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This video talks about Geothermal energy and even mentions how the general public uses the same idea for hot springs.

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This video talks about Geothermal energy and even mentions how the general public uses the same idea for hot springs.

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Geothermal Energy

The prefix geo-, like you've seen before in the words 'geology' and 'geography', is a Greek work meaning Earth. The term thermal is similar to the word thermometer and thermal underwear, and it means heat. We put the terms together in the word geothermal to describe heat coming from the earth. There are two sources of Earth's heat, or geothermal energy: the leftover heat from the formation of our planet and radiogenic heat, which is the heat resulting from radioactive decay within Earth. Both heat sources are naturally occurring and provide abundant energy that can be harnessed for human energy needs.

Capturing Earth's Heat

Prehistorically, and until recently, people could only make use of geothermal energy that made its way to Earth's surface, primarily as geothermal hot springs used for recreational and medicinal bathing. The oldest known pool created for this purpose was built in China in the 3rd century BCE, during the Qin dynasty. Today, geothermal baths continue to lure relaxing vacationers. The water in these hot springs is warmed as it comes into contact with rocks heated by magma below the earth's surface, so the springs are most common in volcanic areas.

In the 20th century, people started using geothermal energy for electricity generation instead of, or as a supplement to, oil, natural gas, coal, and nuclear power sources. With greater drilling capabilities came the ability to penetrate deep, underground steam reservoirs. Although geothermal energy is present everywhere on Earth, it is still most easily accessible in volcanic areas, which can typically be found above subducting tectonic plate boundaries, where one tectonic plate sinks beneath another, partially melting and creating volcanoes at the earth's surface, such as in Alaska and Japan; near divergent plate boundaries, where tectonic plates pull away from each other and magma rises to the surface, such as in Iceland; and over hot spots, where mantle material rises beneath the crust, such as in Hawaii and Yellowstone National Park. In these areas, magma is found at shallow depths, bringing geothermal heat close enough to the surface to be drilled and captured for our use at geothermal electricity stations.

Advantages of Geothermal Energy Use

Harnessing geothermal energy can have fewer environmental impacts than exploiting other energy sources. As a cleaner resource, there tends to be little airborne emissions from geothermal electricity stations. Highly developed drilling methods safely tap into geothermal energy reservoirs with little risk of releasing geothermal fluids, and the land area over geothermal reservoirs can still be used as farmland.

As an alternative to oil, natural gas, and coal, geothermal electricity produces far fewer carbon emissions. It, therefore, does not contribute as much to greenhouse gas production and the resulting climate change. Unlike fossil fuels, which require millions of years of heat and pressure to produce, geothermal energy is considered to be a renewable resource. The earth's heat sources are limitless on the timescales of human life, and we need only water in contact with this heat to produce steam to capture for our electricity consumption.

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advantages & disadvantages - video & lesson transcript | study.com

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What Is Geothermal Energy? - Definition, Advantages & Disadvantages - Video & Lesson Transcript | Study.com

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The prefix geo-, like you've seen before in the words 'geology' and 'geography', is a Greek work meaning Earth. The term thermal is similar to the word thermometer and thermal underwear, and it means heat. We put the terms together in the word geothermal to describe heat coming from the earth.

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Lightning can strike 60 miles away from the nearest rainfall. If you hear thunder, you are within striking distance!
NPS Photo

Lightning

Summer storms include lightning, a powerful force which can and does kill. All thunderstorms produce lightning and there is no safe place outside during a storm - you must go indoors.

Lightning can strike up to 60 miles (16 kilometers) away from the nearest rainfall. If you hear a clap of thunder, a thunderstorm is within 10 miles (16 kilometers). So, if you hear thunder, you are within lightning striking distance!

Appropriate shelter is a building with walls, a roof, and a floor. A hard-top vehicle with all doors closed and windows completely closed can also be appropriate shelter.
If you are caught in a lightning storm without shelter:

If in a group, spread out at least 50 feet apart to minimize the chance of everyone being struck.

Adopt the lightning position - crouch down on the balls of your feet, keeping them as close together as possible. Don't allow other body parts to touch the ground and cover your ears!

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Monsoon Season (U.S. National Park Service)

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Summer storms include lightning, a powerful force which can and does kill. All thunderstorms produce lightning and there is no safe place outside during a storm - you must go indoors. Lightning can strike up to 60 miles (16 kilometers) away from the nearest rainfall.

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(Daniel Boulder) A video about climate change and it's impacts

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(Daniel Boulder) A video about climate change and it's impacts

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This video gives easy to understand evidence on what climate change is and why it is occurring. It explains the Greenhouse Effect in easy to understand language while also mentioning the massive amounts of CO2 increases since the industrial revolution.

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Causes and Effects of Climate Change | National Geographic

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(Colton Jenkins) We found a potential solution for mosquitoes and their disease

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(Colton Jenkins) We found a potential solution for mosquitoes and their disease

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Scientists along with Janneth Rodrigues a scientific lead at GlaxoSmithKline stumbled upon a microbe in a mosquitoes stomach that naturally dislikes malaria. I Find it fascinating that we found a natural deterrent to malaria in mosquitoes. Janneth teamed up with researchers at John Hopkins Bloomberg to find what exactly in the microbe prevented malaria growth. The teams found D. tsuruhatensis(D) which is a bacterium that prevents the growth of malaria born bacteria, this bacterium does not pass from mosquitoes to each other but it does pass with little contact physically and does not harm the bug. The bacterium is looking like a good tool humans could use to fight the sickness in bugs without having to obliterate them. Scientists are testing the bacterium on other insects to see if it would be detrimental to release it into the wild but the research is looking up.

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Microbe stops mosquitoes from harboring malaria parasite

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Strategy could provide additional weapon against spread of deadly disease

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National Environmental Satellite, Data, and Information Service

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Mexico's Popocatépetl Volcano, whose name is the Aztec word for smoking mountain, began belching out towering clouds of ash this week.

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Kayla Nelson
A lightning bolt flashes in the skies north of Davis, Oklahoma, United States. A sudden discharge of electrical energy in the atmosphere, a lightning bolt is accompanied by a clap of thunder, and for this reason is also known as a thunderbolt. Thunderbolts are an important symbol of power and authority, wielded by gods such as Indra and Thor, as well as marking the fictional wizard Harry Potter.

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Lightning is an electric charge or current. It can come from the clouds to the ground, from cloud to cloud, or from the ground to a cloud.

Lightning is a product of a planet's atmosphere. Raindrops very high up in the sky turn to ice. When many small pieces of these frozen raindrops collide with each other in a thundercloud, they create an electrical charge. After some time, the entire cloud fills with an electrical charge. The negative charges (electrons) concentrate at the bottom of the cloud. The positive and neutral charges (protons) and neutral charges (neutrons) gather at the top of the cloud.

Negative charges and positive charges attract each other. Thunderclouds are full of electrical charges connecting with each other. These connections are visible as lightning.

On the ground beneath the cloud's negative charges, positive charges build up. The positive charge on the ground concentrates around anything that protrudes, or sticks up-like trees, telephone poles, blades of grass, even people. The positive charges from these objects reach up higher into the sky. The negative charges in the thundercloud reach lower. Eventually, they touch. When they touch, lightning is created between the two charges.

This connection also creates thunder. Thunder is simply the noise lightning makes. The loud boom is caused by the heat of the lightning. When the air gets very, very hot, the heat makes the air explode. Since light travels much, much, faster than sound, you'll see lightning before you hear thunder.

To figure out how far away a storm is, start counting seconds as soon as you see lightning. Stop when you hear thunder. The number you get divided by five is approximately the number of miles away the storm is. For example, if you see lightning and get to 10 before you hear thunder, the storm is about two miles (3.2 kilometers) away.

Lightning Safety

All thunderstorms and lightning storms are dangerous. Lightning is very, very hot-hotter than the surface of the sun. It can reach 28,000 degrees Celsius (50,000 degrees Fahrenheit). Lightning is more likely to strike objects that stick up off of the ground, including people. In the U.S., lightning kills an average of 58 people each year. That's more deaths than are caused by tornadoes and hurricanes.

If you hear thunder or see lightning, you may be in danger. If you hear thunder, the storm is nearby. Go inside a safe place. Stay away from open areas, like fields, and tall objects, like trees or telephone poles. Stay away from anything metal, too, like chain-link fences, bikes, and metal shelters. Since water is a great conductor of electricity, you should get out of a pool if you're swimming and stay away from puddles and any other water. If you're in an area where there is no shelter, crouch low to the ground, but don't lay down flat. If you're in a group, stand at least five meters (15 feet) from anyone else.

Fast Fact

Greased Lightning
Greased lightning is a description for something that is very fast and very powerful. But even the slipperiest substances, like grease, cant be applied to real lightning, of course!

Fast Fact

Imperial Lightning
Lightning strikes the iconic American Empire State Building in New York City about 100 times every year.

Fast Fact

Make Your Own Lightning
The same process that creates lightning is possible to experience at home. Rub your feet on a carpet, then touch a metal doorknob. Do you feel a shock? That's static electricity. Static electricity occurs when an object has too many electrons, giving it a negative charge. The negative charge of your body is attracting the positive charge of the metal in the doorknob. This is a less-dangerous version of the negative charges in a thundercloud attracting the positive charge in the ground beneath.

Media Credits

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Illustrators

Mary Crooks, National Geographic Society

Editors

Jeannie Evers, Emdash Editing, Emdash Editing

Producer

National Geographic Society

other

Last Updated

November 29, 2022

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Lightning is an electric charge or current. It can come from the clouds to the ground, from cloud to cloud, or from the ground to a cloud.

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Treasure Hunt: The first U.S. nationwide geological survey in a generation could reveal badly needed supplies of critical minerals

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Treasure Hunt: The first U.S. nationwide geological survey in a generation could reveal badly needed supplies of critical minerals

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AUDREY HALL
Living in a world where technology is moving faster than humans, there is a constant search for growth from all areas of the world. This created inner conflict for myself. I appreciate the technology in my life and how we have a greater, faster connection to the world and information. At the same time I understand how it can be environmentally detrimental. This article discusses the need for technology and controlling emission levels, creating an essential need for mining materials. Mining the Adirondack mountains for technology sounds heartbreaking and how does that help our environment to destroy our environment. We are losing green space every day in the world, maybe we just need to loose some of the tech. It makes me think about how we are changing the geology of our planet with each device we buy.

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Read Time: 8 minutes

Lightning bolts can be deadly or destructive, but some researchers propose they might also have supplied essential elements for the first life on Earth. In particular, a ll life uses the element phosphorus. It's found in everything from our genetic material to our cell membranes, but most of the phosphorus on Earth is locked up in solid minerals in the form of . Each phosphorus atom in a phosphate mineral is tightly bound by 4 oxygen atoms, making it extremely difficult for life to extract.

Today, phosphorus is released when phosphate minerals are broken down by interacting with water and gases in a process called weathering . Weathering is accelerated by plant roots that break rocks into soil and by microbes that secrete acids and dissolve minerals. Man-made fertilizers are also a major source of phosphorus due to widespread agricultural use .

In other words, the modern biosphere works together to release tightly bound phosphorus atoms from their phosphate cages to share with all forms of life on Earth. But what about the first cells struggling to eke out a living billions of years ago - they hadn't developed ways to deconstruct phosphate minerals, so where did they get their phosphorus? Scientists call this conundrum the phosphate problem .

To solve the phosphate problem, scientists propose early life must have used more accessible forms of phosphorus, termed reactive phosphorus . Unlike phosphate, minerals containing reactive phosphorus are incredibly rare on Earth. Most examples have been found in meteorites, so some researchers the original cells got their phosphorus from frequent meteorite impacts . However, this source would have required the reactive phosphorus in the meteorites and any nearby proto-life to survive the impacts.

Scientists have also found reactive phosphorus in rocks formed from lightning strikes, called fulgurites . This discovery prompted a team led by researchers from Germany to test whether lightning could have supplied the majority of phosphorus to early life. To do so, they attempted to synthesize phosphorus-bearing fulgurites from lightning in the lab. Their approach improved on because they used natural phosphate minerals rather than silica sand, and they applied a continuing electrical current rather than a single spark, which they argued better simulated how natural lightning forms fulgurites.

The scientists put about half a pound (250 grams) of crushed phosphate minerals inside an insulated sample tube. They explained natural lightning consists of a short burst of high magnitude current followed by a longer-duration continuing current of a lower magnitude. To simulate this in the lab , the team first zapped the sample with an intense electrical pulse for around 100 microseconds, or 1/10,000 th of a second, using a high-voltage generator called a Marx generator . They immediately followed this with a lower-voltage electrical current for half a second using a standard DC power source.

Their experiment produced a brown crystalline solid about the size of a dime with a hollow pit in its center. The team explained a pit like this is common in natural fulgurites. Around the central crater they also saw needle-like crystals of newly-formed minerals extending away from the pit in the direction of lightning strike. They interpreted these structures to indicate the lightning had fully melted and fused the rock powder to form a fulgurite.

The scientists characterized the fulgurite with a variety of chemical methods using X-rays, lasers, and electron beams. They found it was made up almost entirely of phosphate, but with no signs of reactive phosphorus in it. They suggested this was because any reactive phosphorus phases formed were too small to identify with these analyses.

For a closer look, they used a method that can image magnetic fields around the nuclei of atoms. With this method the team found magnetic patterns suggestive of reactive phosphorus phases in the fulgurite. They estimated up to 5% of the sample was reactive phosphorus, higher than of 0.2 to 3% from other lab-produced fulgurites.

The scientists showed lightning can produce small amounts of reactive phosphorus from crushed phosphate minerals in the lab. But does this mean fulgurites were a likely food source for early life? The authors stressed the total supply of reactive phosphorus on early Earth would have depended on unknown phenomena like the rate of lightning discharge and the type of rocks it struck. They suggested future experiments should test how the composition and grain size of the target materials affect the supply of reactive phosphorus.

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Did lightning provide food for life's beginning?

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Lightning bolts can be deadly or destructive, but some researchers propose they might also have supplied essential elements for the first life on Earth. Scientists made reactive phosphorus in the lab...

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Rising rates of suicide, depression accelerated by pandemic among U.S. kids (Posted by Dylan Hymas)

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Rising rates of suicide, depression accelerated by pandemic among U.S. kids (Posted by Dylan Hymas)

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This article was interesting to me talking about how the mental health crisis among children and teens has gotten progressively worse since the pandemic.

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“I felt so alone”: Rising rates of suicide, depression accelerated by pandemic among U.S. kids

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Sharyn Alfonsi reports from Wisconsin where rates of adolescent self-harm and attempted suicide have nearly doubled since 2019.

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Acts of kindness are frequent and universal 

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Acts of kindness are frequent and universal 

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~ Posted by Maxwell. Brown

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A study by researchers from UCLA, Australia, Ecuador, Germany, the Netherlands and the U.K. found that people around the world signal others for assistance every couple of minutes. The research, which examined behaviors in towns and rural areas in several different countries, revealed that people comply with these small requests for help far more often than they decline them. The findings suggest that people from all cultures have more similar cooperative behaviors than prior research has established.

A new study by UCLA sociologist Giovanni Rossi and an international team of collaborators finds that people rely on each other for help constantly.

In the study, published in Scientific Reports, the authors -- who also included researchers at universities in Australia, Ecuador, Germany, the Netherlands and the U.K. -- explore the human capacity for cooperation. They found that people signal a need for assistance, such as asking someone to pass them a utensil, once every couple of minutes.

And the research revealed that those requests for help do not go unanswered: Across cultures, people comply with these small requests far more often than they decline them. On the rare occasions when people do decline, they explain why.

Those human tendencies -- to help others when needed and to explain when such help can't be given -- transcends cultural differences, suggesting that, deep down, people from all cultures have more similar cooperative behaviors than prior research has established.

The new findings help solve a puzzle generated by prior anthropological and economic research, which has emphasized variation in rules and norms governing cooperation.

For example, while whale hunters of Lamalera, Indonesia, follow established rules about how to share out a large catch, Hadza foragers of Tanzania share their food more out of a fear of generating negative gossip. In Kenya, wealthier Orma villagers are expected to pay for public goods such as road projects. Wealthy Gnau villagers of Papua New Guinea, on the other hand, would reject such an offer because it creates an awkward obligation to reciprocate for their poorer neighbors.

"Cultural differences like these have created a puzzle for understanding cooperation and helping among humans," said Rossi, the paper's first author. "Are our decisions about sharing and helping shaped by the culture we grew up with? Or are humans generous and giving by nature?"

To answer those questions, the authors analyzed over 40 hours of video recordings of everyday life involving more than 350 people in geographically, linguistically and culturally diverse sites -- towns in England, Italy, Poland and Russia, and rural villages in Ecuador, Ghana, Laos and Aboriginal Australia.

The analysis focused on sequences in which one person sent a signal for help, such as asking directly or visibly struggling with a task, and another person responded. The authors identified more than 1,000 such requests, occurring on average about once every two minutes. The situations involved "low-cost" decisions about sharing items for everyday use or assisting others with tasks around the house or village, for example.

Such decisions are many orders more frequent than "high-cost" decisions such as sharing the spoils of a successful whale hunt or contributing to the construction of a village road, the types of decisions that have been found to be significantly influenced by culture.

People complied with small requests seven times more often than they declined, and six times more often than they ignored them. People did sometimes reject or ignore small requests, but a lot less frequently than they complied. The average rates of rejection (10%) and ignoring (11%) were much lower than the average rate of compliance (79%).

The preference for compliance held across all cultures and was unaffected by whether the interaction was among family or non-family members.

People helped without explanation, but when they declined, 74% of the time they gave an explicit reason. That suggests that while people decline helping only for a good reason, they give help unconditionally, without needing to explain why they are doing it.

"A cross-cultural preference for compliance with small requests is not predicted by prior research on resource-sharing and cooperation, which instead suggest that culture should cause prosocial behavior to vary in appreciable ways due to local norms, values, and adaptations to the natural, technological, and socio-economic environment," said N. J. Enfield, the paper's corresponding author and a linguist at the University of Sydney. "These and other factors could in principle make it easier for people to say 'no' to small requests, but this is not what we find."

The findings suggest that being helpful is an ingrained reflex in the human species, Rossi said.

"While cultural variation comes into play for special occasions and high-cost exchange, when we zoom in on the micro level of social interaction, cultural difference mostly goes away, and our species' tendency to give help when needed becomes universally visible," he said.

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behavior; racial issues; social psychology; consumer behavior; stem education; resource shortage; popular culture; poverty and learning

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Small acts of kindness are frequent and universal, study finds: Around the world, research reveals, people help each other about every 2 minutes

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A study found that people around the world signal others for assistance every couple of minutes. The research, which examined behaviors in towns and rural areas in several different countries, revealed that people comply with these small requests for help far more often than they decline them.

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The Anatomy of Glacial Ice Loss (posted by Alexander Kroe)

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The Anatomy of Glacial Ice Loss (posted by Alexander Kroe)

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This article discusses the impact climate change has on glacial ice lost. It is interesting read about the natural ratio required to have glaciers. There needs to be more snow falling than melting. With the Earth's temperature increasing, more ice is melting than is falling. Especially in the summer, where warm summer air melts the surface of the glacier, and causes the fresh glacier water to mix with the warm ocean water. The warm ocean water is brought up to the surface and causes the glacier to melt faster. Scientists also say that if large landmasses with ice sheets continue to melt (like Antarctica and Greenland), the oceans can rise by almost 210 feet.

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Climate Change: Vital Signs of the Planet

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Greenland and Antarctica are home to most of the world's glacial ice - including its only two ice sheets - making them areas of particular interest to scientists. Combined, the two regions also contain enough ice, that if it were to melt all at once, would raise sea levels by nearly 215 feet (65 meters) - making the study and understanding of them not just interesting, but crucial to our near-term adaptability and our long term survival in a changing world. Credit: NASA

When an ice cube is exposed to a heat source, like warm water or air, it melts. So, it's no surprise that a warming climate is causing our glaciers and ice sheets to melt. However, predicting just how much the glaciers and ice sheets will melt and how quickly - key components of sea level rise - is not nearly as straightforward.

Glaciers and ice sheets are far more complex structures than ice cubes. They form when snow accumulates and is compressed into ice by new snow over many years. As they grow, they begin to move slowly under the pressure of their own weight, dragging smaller rocks and debris across the land with them. Glacial ice that extends to cover large landmasses, as it does in Antarctica and Greenland, is considered an ice sheet.

Get NASA's Climate Change News: Subscribe to the Newsletter "

The processes that cause glaciers and ice sheets to lose mass are also more complex. An ice cube's surface melts when it's exposed to ambient (warm) air. And while warm air certainly melts the surface of glaciers and ice sheets, they're also significantly affected by other factors including the ocean water that surrounds them, the terrain (both land and ocean) over which they move, and even their own meltwater.

Greenland and Antarctica are home to most of the world's glacial ice, including its only two ice sheets. These thick slabs of ice - some 10,000 feet (3,000 meters) and 15,000 feet (4,500 meters) thick, respectively - contain most of the freshwater stored on Earth, making them of particular interest to scientists. Combined, the two regions also contain enough ice that, if it were to melt all at once, would raise sea levels by nearly 215 feet (65 meters) - making the study and understanding of them not just interesting, but crucial to our near-term adaptability and our long-term survival in a changing world.

Ice Loss in Greenland

A glacier is considered "in balance" when the amount of snow that falls and accumulates at its surface (the accumulation zone) is equal to the amount of ice lost through melting, evaporation, calving and other processes.

But with annual air temperatures in the Arctic increasing faster than anywhere else in the world, that balance is no longer achievable in Greenland. Warmer ocean waters surrounding the island's tidewater glaciers are also problematic.

"It's basically like pointing a hairdryer at an ice cube, while the ice cube is also sitting in a warm pot of water," said Josh Willis, principal investigator of NASA's Oceans Melting Greenland (OMG), a project that is investigating the effects of ocean water temperature on melting ice in the region. "The glaciers are being melted by heat from above and below simultaneously."

Although the warm air and the warm water contribute to melting individually, the interplay between the meltwater from the glacier and the warm ocean water also plays a significant role.

When warm summer air melts the surface of a glacier, the meltwater bores holes down through the ice. It makes its way all the way down to the bottom of the glacier where it runs between the ice and the glacier bed, and eventually shoots out in a plume at the glacier base and into the surrounding ocean. The meltwater plume is lighter than the surrounding ocean water because it doesn't contain salt. So it rises toward the surface, mixing the warm ocean water upward in the process. The warm water then rubs up against the bottom of the glacier, causing even more of the glacier to melt. This often leads to calving - ice cracking and breaking off into large ice chunks (icebergs) - at the front end, or terminus of the glacier. Credit: NASA

When warm summer air melts the surface of a glacier, the meltwater bores holes down through the ice. It makes its way all the way down to the bottom of the glacier where it runs between the ice and the glacier bed, and eventually shoots out in a plume at the glacier base and into the surrounding ocean.

The meltwater plume is lighter than the surrounding ocean water because it doesn't contain salt. So it rises toward the surface, mixing the warm ocean water upward in the process. The warm water then rubs up against the bottom of the glacier, causing even more of the glacier to melt. This often leads to calving - ice cracking and breaking off into large ice chunks (icebergs) - at the front end, or terminus, of the glacier.

The complicated shape of the sea floor surrounding Greenland influences how readily this warm water melt can occur. It provides a barrier in some areas - preventing the deep, warmer water from the Atlantic Ocean from reaching glacier fronts. However, the underwater terrain, much like the terrain above water, includes other features like deep canyons. The canyons cut into the continental shelf, allowing the Atlantic waters in. Glaciers sitting in these waters will melt faster than those where the warm water is blocked by underwater ridges or sills.

Ice Loss in Antarctica

In Antarctica, where similar surface and ocean melting processes occur, the topography and bedrock on which the ice sheet sits significantly influence the ice sheet's stability and its contribution to sea level rise.

Researchers separate Antarctica into two regions based on the relationship between the ice and the bedrock beneath it. East Antarctica, the area east of the Transantarctic Mountains, is extremely high in elevation and has the thickest ice on the planet. The bedrock underneath the ice sheet is also mostly above sea level. These features help to keep the east side relatively stable. West Antarctica, on the other hand, is lower in elevation and most of the ice sheet there is thinner. Unlike the east, the ice sheet in West Antarctica sits on bedrock that is below sea level.

"In West Antarctica, we have these glaciers resting on bedrock that is under water. Like in Greenland, there is a layer of warmer ocean water below the cold surface layer. So this warm water is able to flow onto the continental shelf, and then all the way underneath the ice shelves - the floating ice that extends from glaciers and the ice sheet," said NASA Jet Propulsion Laboratory scientist Helene Seroussi. "The water melts the ice shelves from below, which can cause them to thin and break off."

The visualization shows how ocean currents flow around and under Pine Island Glacier in Antarctica. As the water makes its way underneath the ice shelf, it erodes the ice shelf from the bottom causing it to become thinner. The visualization was produced using the "Estimating the Circulation and Climate of the Ocean" (ECCO) V3 ocean circulation model, the 100 meter "Reference Elevation Model of Antarctica" (REMA) surface elevation and the 450 meter bed topography and ice thickness BedMachine Antarctica V1 datasets. The surface is mapped with scenes from NASA's LandSat 8 satellite. Exaggeration factors of 4 and 15 - above and below sea level respectively - were used for clarity. Credit: NASA / Cindy Starr

That matters because the ice shelves act like corks. They hold back the ice that is flowing from upstream, slowing its approach to the ocean where it raises sea level. When the ice shelves calve, the cork is essentially removed, allowing more inland ice to flow freely into the ocean. Furthermore, this leads to retreat of the grounding zone - the area where the ice separates from the bedrock and begins to float.

"The grounding zone delineates floating ice, which is already accounted for in the sea level budget from grounded ice which is not accounted for in the budget," said ICESat-2 scientist Kelly Brunt of NASA's Goddard Space Flight Center and the University of Maryland. "Floating ice is like an ice cube floating in a glass. It doesn't overflow the glass when it melts. But when non-floating ice is added to the ocean, it's like adding more ice cubes to the glass which will cause the water level to rise."

The bedrock in West Antarctica is also reverse sloping - meaning it is higher at the edges and gradually becomes deeper further inland. So each time the grounding zone retreats inland, thicker ice is exposed to the ocean water and the glacier or ice sheet becomes grounded in deeper water. This allows even more ice to flow from upstream into the ocean.

"It's concerning in West Antarctica because as we push the grounding zones back, the downward, reverse slope means that there's really no backstop, nothing to interrupt this cycle of melting and retreat," said Brunt. "Our maps of the bedrock under the ice sheet are not as comprehensive as they are in Greenland, in part because Antarctica is far less accessible. Because of that, we really don't know if there are any little bumps or peaks down there that might help to slow the retreat."

West Antarctic glaciers like Thwaites and Pine Island are already retreating faster than they were in the past. This is problematic because they provide a main pathway for ice from the West Antarctic Ice Sheet to enter the Amundsen Sea and raise sea levels.

Overall, melting and ice loss have accelerated at both poles in recent years. The more we learn about the processes and interactions that cause it, some of which were discussed here, the better we'll be able to accurately and precisely predict sea level rise far into the future.

News Media Contacts

Ian J. O'Neill / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649 / 818-354-0307
ian.j.oneill@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov

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national aeronautics and space administration

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By Esprit Smith,
NASA's Earth Science News Team

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The Anatomy of Glacial Ice Loss - Climate Change: Vital Signs of the Planet

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When an ice cube is exposed to a heat source, like warm water or air, it melts. So, it's no surprise that a warming climate is causing our glaciers and ice sheets to melt. However, predicting just how much the glaciers and ice sheets will melt and how quickly - key components of sea level rise - is not nearly as straightforward.

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Postpartum depression among mothers in  Ethiopia

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Postpartum depression among mothers in  Ethiopia

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posted by Matteus Manzo

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Department of Public Health, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia

Department of Medicine, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia

Department of Biomedical Sciences, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia

Department of Statistics, College of Natural and Computational Sciences, Debre Tabor University, Debre Tabor, Ethiopia

Department of Pediatrics and Neonatal Nursing, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia

Background: Postpartum depression (PPD) is a non-psychotic depressive disorder of variable severity, and it can begin as early as 2 weeks after delivery and can persist indefinitely if left untreated. In Ethiopia, the prevalence of postpartum depression is high. There is a dearth of literature to determine factors associated with postpartum depression in Ethiopia, specifically in the study area.

Objective: This study aimed to identify factors associated with postpartum depression among mothers in Debre Tabor Town, Northcentral Ethiopia.

Method: A community-based unmatched case-control study was conducted among mothers who were living in Debre Tabor Town and fulfilled the inclusion criteria. Postpartum mothers were selected using a simple random sampling technique from the listed sampling frame at the health center. Then, the sample cases and controls were interviewed until the sample size was fulfilled by using a consecutive sampling method. The data were entered into the EPI data version 4.6 and then imported and analyzed using SPSS version 25. Descriptive statistics of different variables were done by cross-tabulation. Binary logistic regression was used to assess the determinant factors with the outcome variable. A P-value of < 0.05 was considered to declare statistical significance.

Results: A total of 308 postnatal mothers living in Debre Tabor Town were included, with a 97.5% response rate. History of substance use in the previous 3 months (AOR: 6.47, 95% CI; 2.61, 15.74), current baby illness (AOR: 3.9, 95% CI; 1.5, 10.12), marital dissatisfaction (AOR: 2.41, 95% CI; 1.22, 4.75), unplanned current pregnancy (AOR: 3.46, 95% CI; 1.32, 9.12), and breastfeeding (AOR: 0.22, 95% CI; 0.09, 0.55) were independent factors that affected the occurrence of PPD.

Conclusion: This study revealed that a recent history of substance use (in the past 3 months), current baby illness, marital satisfaction, unplanned current pregnancy, and breastfeeding were associated with postpartum depression. Healthcare providers working in maternal and child health clinics and health extension workers should give special attention to postpartum mothers who have had a history of substance use, current baby illness, unplanned pregnancy, non-breastfeeding mothers, and mothers with poor marital satisfaction.

Background

Postpartum depression (PDD) also known as postnatal depression is a non-psychotic depressive disorder of variable severity it can begin as early as 2 weeks after delivery and can persist indefinitely if left untreated. Depressive disorders are the leading cause of global disability, and PDD is a clinical depression with symptoms that can include a feeling of fatigue, social withdrawal, sadness, changes in sleeping and eating patterns, guilt, crying, loneliness, and low self-esteem lasting longer than 2 weeks ( 1- 3). Nearly one-fifth of the global disease burden has been ascribed to neuropsychiatric disorders, including those disorders that occur during the postpartum period. These estimates indicate the importance of addressing mental disorders in public health ( 4). According to a standardized diagnostic and statistical manual, postpartum depression is one type of depressive episode, which occurs within 1 year of childbirth. However, it can also manifest as the occurrence of a major depressive episode within 4 weeks after delivery. The fundamental neurobiological changes result from developmental connections between genetic susceptibility and environmental factors rather than a simple chemical imbalance ( 1, 5).

In low and lower-middle-income countries, particularly among poorer women, the prevalence of postpartum depression is high ( 6, 7). The prevalence rates vary by geographic location, with Southern Africa having the highest rate (39.96%). In industrialized nations or high-income countries, there is a much lower prevalence of PPD. Furthermore, the findings from various studies show that when marital status, educational level, social support, spouse care, violence, gestational age, breastfeeding, child mortality, pregnancy plan, financial difficulties, partnership, life stress, smoking, alcohol intake, and living conditions were factored into the pooled estimates, there was a significant difference in PPD rates ( 8). In studies conducted in Ethiopia, the prevalence of postpartum depression is high in different places; for instance, in Bahir Dar, it is 22.2% ( 9), in Harar, 13.11% ( 10), in Debre Birhan, 15.6% ( 4), and Ankesha, 23.7% ( 11).

Maternal depression refers to a wide range of depressive disorders that can affect mothers (up to 12 months postpartum) and expectant moms. Prenatal depression, postpartum depression, and postpartum psychosis are examples of these depressive illnesses. Maternal depression is becoming more widely recognized as a global public health concern with far-reaching consequences for an individual's career, family, and the baby's health and development ( 12, 13). Untreated postpartum depression has a serious adverse long-term effect on mothers and their children. For the mother, the episode can be the precursor of chronic recurrent depression. On the other hand, for her children, it can contribute to emotional, behavioral, and cognitive problems in later life ( 14, 15). Since depressed mothers stop breastfeeding earlier, the infants are more likely to have episodes of diarrhea, and poor mother-infant relationships, which can affect child development and other infectious diseases ( 7, 16). The risk of depression increases significantly during pregnancy and clinically significant depressive symptoms are common in mid and late trimesters ( 17- 19).

Stressful recent life events, poor social support, early life abuse, previous history of depression, abuse by an intimate partner, low levels of maternal education, low socioeconomic status, and a history of mental illness are some factors that have been associated with postpartum depression ( 1, 5, 11, 20, 21).

Even though different cross-sectional studies have been conducted in different parts of Ethiopia on postpartum depression, there is a dearth of research that determines causal factors for PPD using case-control studies at the community level. Therefore, this study aimed to identify the determinants of postpartum depression among mothers in Debre Tabor Town, Northcentral Ethiopia, using a community-based unmatched case-control study.

Methods and materials

Study design, area, and period

A community-based unmatched case-control study was conducted in Debre Tabor Town, the capital of the South Gondar Zone, which is 103 km away from Bahir Dar the capital city of Amhara National Regional State, and 666 km away from Addis Ababa capital city of Ethiopia. There are six primary schools, three health centers, and one referral hospital in the Town. According to the 2007 E.C population census report, the total population of the Zone was 2,578,906. This study was conducted from 1 to 30 December 2020.

Source population

The source population was postnatal mothers living in Debre Tabor Town and within 6 weeks after their delivery.

Cases

The cases were post-partum mothers who scored ≥10 cut-off points of the EPDS and confirmed using the Diagnostic and Statistics Manual, Fourth Edition, Text Revision ( 22).

Controls

Controls were the post-partum mothers who score < 10 cut-off point of the EPDS.

Inclusion and exclusion criteria

All postnatal mothers living in Debre Tabor Town within 6 weeks after delivery were included in this study. Postpartum mothers who had a hearing impairment or were unable to talk were not included in the study.

Sample size and sampling procedure

To determine the sample size, an unmatched case-control study sample size determination method using Open EPI INFO version 7 software was used. Among several exposure variables, the selection of the appropriate exposure variables in controls was done based on the main interest variables of cases of postpartum depression. This research used a study done in Bahir Dar, Northwest Ethiopia, where the proportion of postpartum depression among mothers whose babies were hospitalized was 41.6% and its effect size (AOR) was 2.24 ( 9). During the sample size determination, we used the assumption of a 95% confidence interval, 80% power, and 1:3 case-control ratio with a 10 % non-response, yielding a total sample size of 316 (79 cases and 237 controls).

Post-natal mothers were chosen using particular household numbers. A list of households containing a coded list of post-partum mothers was available for each kebeles (the lowest administrative unit in Ethiopia containing at at-least 5,000 residents) from health extension workers at each health post. Proportional allocation to size was done to decide the study participants from each kebeles. After that, postpartum mothers were selected using a simple random sampling technique from the listed sampling frame. A house-to-house interview/screening using the Edinburg postnatal depression scale (EPDS) was undertaken based on the particular household numbers for selected postpartum mothers. Cases were identified by screening randomly selected post-partum mothers. A positive screening (score ≥10 cut-off points of EPDS) as outlined in the Diagnostic and Statistics Manual, Fourth Edition, Text Revision (DSM-IV-TR) was confirmed by a psychiatric nurse. Those confirmed postpartum mothers with PPD were taken as cases by using a consecutive sampling method until the sample size was reached. Those mothers with a negative screen test were taken as controls until the sample size was reached. The lottery method was used to select one participant if there was more than one eligible mother in the one selected household. The respondents were considered non-respondents after two revisits.

Data collection tool and measurement

Data was collected using a structured questionnaire containing questions relating to socio-demographic characteristics, pregnancy, and birth-related factors, newborn-related factors, maternal and family-related factors, psychosocial and psychological factors, and Edinburg postnatal depression scale (EDPS). Data was collected by the data collector after informed consent and assuring the participant that their information was confidential. All the above tools were used to determine factors associated with postpartum depression among postnatal women in Debre Tabor Town.

Postpartum depression was determined when postpartum mothers scored ≥10 cut-off points of the EPDS, which has ten items with the four-Likert scale for each item and a maximum score of 30 and a minimum score of zero ( 23). Substance use during the current pregnancy was defined as a self-report of exposure to at least one of three substances (alcohol, khat, or tobacco) during the current pregnancy 3 months before the interview irrespective of its dose and frequency (Yes/No) ( 24, 25). The level of marital satisfaction was assessed using the three-item Kansas marital satisfaction scale, with each having a seven-Likert scale ranging from one (extremely dissatisfied) to seven (extremely satisfied) and a maximum score of 21 and a minimum of 3. A cut-off point of 17 and above was taken to identify satisfaction with current marital relations ( 26). Social support is a measure of available support that women perceive or believe that people in their network will assist in times of need and was measured by the Oslo 3-item social support scale. A score between 3 and 8 is classified as "poor support", 9-11 is "moderate support" and 12-14 is deemed "strong support" ( 27). In this study, a social support score of less than nine was categorized as poor or no social support; scores ranging between 9 and 14 were considered moderate to strong support and merged as "yes" for social support.

Study variables

Dependent variable

Postpartum depression

Independent variables

Women-related variables

Age, marital status, residence, religion, family income, educational status, history of family depression, history of chronic illness, and substance use (alcohol, khat, tobacco).

Obstetrics factors

Number of pregnancies, number of birth, number of miscarriages and stillbirths, number of live children, place of birth, use of vacuum and episiotomy, preferred sex of baby, gestational age, baby illness, history of pregnancy complication, feeding of the baby, and planned pregnancy.

Psycho-social factors

Partner support, psycho-social support, and history of family mental illness (See Figure 1).

Data quality management and analysis

The questionnaire was written in English, then translated into Amharic, and then back into English. The data collection instrument was pre-tested on 5% of the sample size in Woreta Town. After the questionnaire was pretested, the anticipated time required and final amendments were made. Finally, the data were entered into EpiData and the error reports were double-checked. After exporting to SPSS, cleaning was done using visualizing, sorting, and calculating frequencies data processing and analysis.

Data were cleaned, modified, and entered into EpiData version 4.6 before being imported into SPSS version 25. The frequency distribution table, graph, and summary measures were used to describe descriptive statistics. Descriptive statistics of different variables were done by cross-tabulation. Bivariate and multivariable binary logistic regression models were used for analysis. During bivariate analysis, variables with p < 0.25 were retained for inclusion in the multivariable analysis in the final model, then variables at p < 0.05 and 95% CI were considered statistically significant and independently of postpartum depression. Multi-collinearity was checked to see the linear correlation among the independent variables by using the variance inflation factor. Both Hosmer-Lemeshow's test ( P = 0.425) and Omnibus tests ( P = 0.000) were used to check model fitness.

Ethical considerations

Ethical clearance was obtained from the ethical review committee of Debre Tabor University with ethical review number HSC/2222/2020. Permission to conduct the study was also obtained from the Debre Tabor Town Health office. Written consent was obtained from the respondents who were all aged above 16 years and this was confirmed by the ethical review committee. Confidentiality and anonymity were ensured throughout the execution of the study.

Results

Socio-demographic charcateristics of postpartum mothers

In the study, 308 mothers were included, and the response rate was 97.5%. Among the study participants, 115 (37.4%) were aged 25-34 and almost 214 (69.5%) were from rural areas. Most of the study participants 292 (94.8%) were orthodox Christians. Hundred thirty-five (43.8%) participants were illiterate and 147 (47.7%) could read and write. About 182 (59.1%) of the participants earned a monthly income of less than < 750 Ethiopian Birr (See Table 1).

Obstetric and clinical characteristics of postpartum mothers

Of the 308 study participants, most respondents (194, 63%) were multigravida (give birth > 1) and 114 (37%) were primigravida (having a first child). Almost 65% of the respondents had two or more living children during the study period. About 24 (7.8%) had undergone termination of pregnancy and stillbirths, of which 14 (58%) had experienced it once and 10 (42%), two times. Nearly 298 (96.8%) of participants, delivered the last child in a health institution and 14 (4.5%) mothers were assisted with vacuum during delivery and 68 (22%) had an episiotomy. Twenty-five (8.1%) participants reported that the recent pregnancy was unplanned (See Table 2).

Newborn-related factors (recent pregnancy)

About 166 (53.9%) of the babies (from the recent pregnancy) were male and the rest were female. While 261 (84.7%) babies had a full-term gestational period, the rest were preterm. Most of the study mothers (273, 88.6%) breastfed their child, and only 34 (11%) of the newborns encountered illness during the first few months of their birth (the duration of this study) and 24 (20.8%) of mothers had a history of fetal death (See Table 3).

Psychosocial factors and social support among postpartum

Social support status was assessed using the Oslo-3 social support scale. Of the total study participants, the majority 298 (97%) had poor social support, 31 (10.1%) had a history of substance use, 91 (29.5%) had psychosocial stressors and 22 (7.2%) had a history of family mental illness (See Table 4).

Determinants of postpartum depression

To identify factors independently affecting postpartum depression, all variables at a significance level of 0.25 in the bivariate analysis were retained for inclusion in the multivariable logistic analysis. From the total twelve variables that were entered in the multivariable logistic regression using the backward stepwise method, five variables were found to have a significant independent association with PPD in the final model. These were: history of substance use in the previous 3 months, current baby illness, marital satisfaction, planned current pregnancy, and breastfeeding.

The odds of developing PPD among postpartum mothers who have a history of substance use in the past 3 months were six times more likely than those who had no history of substance use (AOR: 6.47, 95% CI; 2.61, 15.74). Mothers whose babies were currently ill (first 6 months of their birth which was also the duration of our study) were three times more likely to have PPD compared to those whose babies were healthy (AOR: 3.9, 95% CI; 1.5, 10.12). Postpartum mothers with marital dissatisfaction were two times more likely to have PPD than satisfied ones (AOR: 2.41, 95% CI; 1.22, 4.75). Mothers whose current pregnancies had been unplanned were three times more likely to have PPD than those whose current pregnancies had been planned (AOR: 3.46, 95% CI; 1.32, 9.12). Breastfeeding mothers were 80% less likely to have PPD than mothers who were not breastfeeding (AOR: 0.22, 95% CI; 0.09, 0.55; See Table 5).

Discussion

This study aimed at determining the factors associated with postpartum depression in Debre Tabor Town. Three hundred and eight mothers were included in the study with a response rate of 97.5%. The overall prevalence of postpartum depression was 77 (25%) in this study. Global studies show differing prevalence rates; for instance, 40% in Canada ( 11), and 34% in Jamaican ( 9). The prevalence rates were lower in our study compared to Canada and Jamaica. The lower prevalence rate in our study might be due to differences in residency and sample size difference. In studies carried out in the eastern Tigray zone and Mizan Aman town, the prevalence of major depression at 6 weeks postpartum was 19% ( 28) and 22.4% ( 20) respectively, which is closer to the findings from our study.

In this study, substance use had a significant association with the occurrence of PPD. This is similar to studies done in Nekemte town, West Ethiopia ( 29), Mizan Aman town, Southwest Ethiopia ( 20), and the US ( 30). The possible justification is that substance use has an impact on the user's emotions and behavior. In the case of substance use in postpartum mothers, there is a risk of PPD. Additionally, to deal with the feelings linked with postpartum depression, some women may turn to substance use. When life turns upside down, sleeping becomes difficult, and the stress of doing everything correctly becomes too much to bear, postpartum women turn to substances to help them cope.

The baby falling ill in the initial months had threefold odds of developing PPD compared to those who had healthier babies. This is consistent with studies done in Bahir Dar Town, Northwest Ethiopia ( 9) and Debre Berhan, Ethiopia ( 4). It is possible that the health outcome of the infants induced more stress in mothers, which eventually affected the mental wellness of the mothers.

Marital satisfaction had an inverse significant association with PPD among postpartum mothers. This is supported by studies done in Mizan Aman town, Southwest Ethiopia ( 20), Bandar Abbas, Iran ( 31), Tirana ( 32), Jahrom, Iran ( 33), and Russia ( 34). The reason for this could be that having a healthy relationship reduces the risk of psychological suffering. A healthy relationship can boost a mother's resilience and help her build coping skills while she adjusts to parenting. In addition to a stressful childbirth event, women may be vulnerable to PPD due to a lack of support, love, affection, and advice from their husbands. Low marital satisfaction makes it difficult to form a proper emotional bond between partners. As a result, the risk of depression increases ( 35).

Unplanned pregnancy was significantly associated with PPD among new mothers. This finding is similar to different studies undertaken in Ethiopia (Nekemte ( 29), Bahir Dar Town ( 9), Mizan Aman ( 20)), and studies done abroad ( 36, 37). This is because unplanned pregnancies are more likely to cause stress or worry during pregnancy, which can lead to postpartum depression. This is due to a lack of preparation for pregnancy, labor, and breastfeeding, as well as related socioeconomic compulsions. Unplanned pregnancy among partnered mothers was linked to a higher risk of psychological distress, which could lead to her partner providing less support ( 35).

This study found that breastfeeding mothers have fewer odds of developing PPD than non-breastfeeding mothers. This is similar to different studies ( 38- 40). The plausible explanation might be that during successful breastfeeding, there is skin-to-skin contact, which positively promotes mother-infant bonding. Maternal-infant touch behaviors, particularly affectionate touch, are influenced by skin-to-skin contact to boost the release of oxytocin. The hormone oxytocin is produced during and after childbirth. It promotes sociability and trust among individuals while also reducing fear and anxiety ( 41) hence, preventing PPD. However, this result is contrary to the findings of Alder and Cox that breastfeeding mothers are at increased risk of PPD ( 42).

This study does not address whether or not mothers have the intention to breastfeed, and whether they face any difficulties or not. Some studies have revealed that mothers who go through negative breastfeeding experiences are at an increased risk of PPD. On the other hand, higher maternal satisfaction with breastfeeding has been associated with the absence of PPD ( 43). There is a very high risk of PPD among mothers who had planned to breastfeed and had not gone on to breastfeed ( 44). Studies show that pain and physical breastfeeding difficulty are related to postnatal depression ( 45), where postpartum depression may reduce rates of breastfeeding or breastfeeding may assist in a swifter recovery from the symptoms ( 46).

Strength and limitation

Unlike hospital-based studies, this study used a community-based study design to determine factors associated with postpartum depression.

The limitation of the study is that it might be susceptible to social desirability bias, and to minimize potential bias we used anonymous surveys and female data collectors. This allowed respondents to answer our questions with relative ease and comfort without having to divulge any identifying details like personal names or addresses.

Conclusion and recommendations

A significant proportion of postnatal mothers had depression, 77 (25%). Major life events and factors such as the recent history of substance abuse in the previous 3 months, current baby illness, marital satisfaction, unplanned current pregnancy, and breastfeeding were independent factors affecting the occurrence of PPD. Healthcare professionals working in maternal and child health clinics should pay special attention to postpartum mothers who have a history of substance abuse, have had an unplanned pregnancy, are non-breastfeeding mothers, and have poor marital satisfaction. Midwives and other health professionals should routinely screen new mothers for postpartum depressive symptoms and link them to mental health services, just like they would monitor other reproductive health problems in mothers attending hospitals and health centers after delivery.

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics statement

The studies involving human participants were reviewed and approved by the Ethical clearance was obtained from the ethical review committee of Debre Tabor University with ethical review number HSC/2222/2020. The patients/participants provided their written informed consent to participate in this study.

Author contributions

FD and NI conceived the original idea and were involved in proposal development, design, data collection, and analysis in all stages of the thesis. FD, WA, DA, AD, NI, YB, GY, AB, EC, and HH were involved in proposal development, analysis, and all stages of the research project. All authors read and approved the final manuscript.

Acknowledgments

The authors' heartfelt gratitude goes to Debre Tabor University for giving us this chance and for dealing with the title. Our deep gratitude goes to Debre Tabor Town health office staff members for their support in our work. We also thank the data collectors and the study participants for their kind replies to our questions.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Abbreviations

DTSH, Debre Tabor Specialized Hospital; EPDS, Edinburg Postnatal Depression Scale; GYN/OBS, Gynecology and Obstetrics; ICU, Intensive Care Unit; NICU, Neonatal Intensive Care Unit; PND, Postnatal Depression; PPD, Postpartum Depression; SPSS, Statistical Package for Social Sciences.

References

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Determinants of postpartum depression among mothers in Debre Tabor town, North-central, Ethiopia: Community-based unmatched case-control study

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BackgroundPostpartum depression (PPD) is a non-psychotic depressive disorder of variable severity, and it can begin as early as 2 weeks after delivery and can persist indefinitely if left untreated. In Ethiopia, the prevalence of postpartum depression is high.

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Taylor Kiser. I thought this video was a nice overall example of how climate change is effecting the planet. Towards the end it does mention how we can combat climate change, but I think more strategies are going to need to be at play. Solar is an amazing energy source and I think we need to implement it further into our society. However I think other methods need to be used simultaneously used. Ongoing research is occurring to determine if planting billions if not trillions of trees would help or if it would change the bio make up of an environment possibly creating a further problem. In any case I think we need to identify many major combative techniques and start deploying them on a mass scale as well as consuming less of our natural resources. Easier said than done but we need to do something before it's too late.

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Causes and Effects of Climate Change | National Geographic

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Climate Change Poses Challenges to Plants and Animals

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Climate Change Poses Challenges to Plants and Animals

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This article discusses the effects of global warming on various animal species across the world.

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Climate Change Poses Challenges to Plants and Animals

In the Rocky Mountains, climate change has raised summer temperatures 0.72˚ F each decade over the last 30 years, while snows are melting three to five days earlier in spring. Wildflowers bloom several days earlier, with peak flowering also occurring earlier. No one knows what this might eventually mean for pollinators. In Australia, warmer winters are forcing mountain pygmy possums out of hibernation earlier than their prey, the bogong moth, so many are starving to death. In Europe, roe deer, whose fertility is triggered by the length of days, are giving birth after the first flowers, which are blooming earlier than in the past. The mismatch of 36 days between birthing times and food availability is resulting in a decline in the deer population's fitness.

According to one study, spring, summer, fall and winter in the temperate zones are all arriving on average 1.7 days earlier than they did before 1950. The U.S. Environmental Protection Agency reports that average temperatures in the U.S. have increased 0.14˚F per decade, and worldwide, the decade from 2001 to 2010 was the warmest on record since measurements began. The changing climate with its more extreme weather is already affecting many plant and animal species and disrupting ecosystem functioning.

The Intergovernmental Panel on Climate Change estimates that 20 to 30 percent of assessed plants and animals could be at risk of extinction if average global temperatures reach the projected levels by 2100. Evolution would have to occur 10,000 times faster than it typically does in order for most species to adapt and avoid extinction.

A 2011 study found that in response to warming temperatures, species are moving to higher elevations at an average rate of 36 feet per decade and to higher latitudes approximately 10 miles per decade, though individual species vary in their rates.

The National Wildlife Federation reports that 177 of 305 North American bird species shifted their range further north by 35 miles in the last 40 years; and over the last century, 14 species of small mammals extended their range 1,640 feet higher in the Sierra Nevada region. But many scientists say climate change is occurring too rapidly for the majority of species to outrun it. And even if some species are able to migrate northward or upward, they could enter territory where there is increased competition for food or unprecedented interactions with species they have never encountered before. Those that are already at their northern limits have no place left to go. For example, as forests move north into the tundra, many Arctic creatures such as caribou, arctic fox and snowy owl are losing their habitat. Other species may not be able to migrate due to geographical obstructions or man-made barriers such as cities or highways.

In addition to driving species to cooler regions, warming temperatures affect the timing of seasonal life cycle events of plants and animals such as mating, blooming or migration. One population of pink salmon in Auke Creek, Alaska, and sockeye salmon in the Columbia River are migrating to spawn earlier than they did 40 years ago in response to warmer water temperatures. The changing conditions can lead to mismatches of life cycle events, making growth or survival more difficult when babies are born or migrating animals arrive before or after their food is available. In one Dutch park, as spring arrives earlier, caterpillars are appearing earlier, but their predators, the great tits, are not always laying their eggs earlier, so the bird population is declining.

Pests and pathogens, however, benefit from warmer temperatures, which enable them to expand their territory and survive through the winter; their populations are on the increase.

From 1997 to 2010, mountain pine beetles destroyed trees on 26.8 million acres in the American West. Warmer winters have helped an oyster parasite extend its range from Chesapeake Bay north to Maine, with the potential to cause large oyster die-offs. The Aedes aegypti mosquito that carries dengue and yellow fever and that is usually found in Texas or the southeastern United States appeared as far north as San Francisco in 2013.

With less winter snowfall to insulate the soil and keep it warm, frozen soils result in more root death and nutrient runoff, which can produce algal blooms and dead zones where nothing can survive. Decreasing snow pack in the mountains can create a greater risk of winter and spring flooding, and means there will be less snowmelt runoff to cool streams in summer and fall. Changes in stream flow and temperature can damage habitat and stress fish and wildlife, disrupting their life cycle events. And as rivers and streams become warmer, warm-water fish are crowding cold-water fish out of their habitat.

Warming oceans become increasingly acidified, stressing corals and causing bleaching and die-offs. Warmer waters also cause the rapid melting of Arctic sea ice, which has ramifications all along the food chain: The decline of sea ice results in the loss of ice algae, which are eaten by zooplankton. Arctic cod, which feed on zooplankton, are the prey of seals, which in turn are the main food of polar bears.

Global warming is also intensifying rainfall, flooding, hurricanes and droughts. Changing precipitation patterns can affect plant growth, the amount of moisture in soils, nutrient runoff, water retention and insect prevalence. In California, drier conditions have meant less food for desert bighorn sheep. The drying up of ponds in Yellowstone National Park has led to the decline of four amphibian species. And in the Sonoran Desert in the southwest, some bird species stop breeding altogether during extreme drought conditions.

Over the last 50 years, the Arctic has warmed two to three times faster than the rest of the planet. The tundra is a treeless expanse with only low-lying growth where the subsoil is permanently frozen. Because of global warming, however, more and more woody deciduous shrubs are appearing. Natalie Boelman, assistant research professor at Lamont-Doherty Earth Observatory, is studying the impacts of the changing conditions here on some of the millions of songbirds from all over the world that migrate to the Arctic in spring and summer to breed because of abundant food sources and fewer predators and parasites.

The increasing shrubbiness of the Arctic means that the habitat and food supply are changing. The Lapland longspurs that Boelman and her team are studying prefer to nest on the open tundra, while the Gambel's white-crowned sparrows favor shrubs. On the open tundra, spiders, beetles and more predator insects are prevalent. The shrubbier areas have many types of flies and grasshoppers, so all the birds are eating more flies which is their preferred food source.

Relative to 30 years ago, the sparrows' range limit has moved north by dozens of miles, tracking the shrubs they like to nest under as the shrubs move north. "Because of changing food availability and environmental conditions, the birds on the northern range are more stressed," said Boelman. "But they are doing it so far." Looking ahead, Boelman predicts there will be an increase in sparrow habitat and a decrease in longspur habitat. "It seems clear that shrub nesters will be happy, but open nesters will have a harder time. ... Maybe the longspurs can move further north, but it's a very waterlogged area, so they may be out of luck unless they can adapt to these shrubbier habitats."

Boelman's team is also researching the impacts of changing seasonality. The birds, which migrate based on day length cues unaffected by climate change, will likely continue to arrive in the Arctic at the same time each year. Their reproduction is timed to dovetail with the availability of insects, so that when chicks are born, there is plenty of food. With spring now beginning earlier, fall arriving later and a resulting longer growing season, Boelman is investigating whether the chicks will be hatching after the period of greatest insect availability and thus have a harder time surviving.

The Arctic generally has very unpredictable spring weather conditions, with huge swings between years. As it turned out, the growing season started 12 days late in 2013. The birds also showed up later, had their babies later, found enough insects to eat and did fine dealing with the delayed snowmelt. The delays had no significant effect on their reproduction. Boelman explained. "Animals living and migrating up there are well adapted to big swings and extremes. Perhaps they will react less to climate change because they are already well adapted. We are looking at if we are starting to exceed the range of conditions they can cope with."

While organisms that adapt evolve through natural selection over many generations, some individual organisms can change their features (developmental, behavioral and physical) during their lifetime in response to the environment through phenotypic plasticity. Plasticity enables organisms with identical genes to exhibit different traits in reaction to climate conditions through altering gene expression. For example, a Rocky Mountain wild mustard plant's traits normally vary according to whether it is growing at a low elevation with a hot, dry climate or at higher elevations under cold, wet conditions. Researchers found that when they simulated climate change by reducing the snowpack at an intermediate elevation, the plants flowered earlier and took on the appearance of the lower elevation plants.

Having phenotypic plasticity could allow some species to remain in place and give others time to migrate and adapt. Having more plasticity could also help some species migrating to new areas better adapt to unfamiliar conditions. How plastic a species is can also potentially evolve over time, as species with genes that allow for plasticity might survive better in changing climate conditions. It's also possible, however, that climate change could cause some organisms to change in ways that make them less able to adapt.

Factors other than plasticity also affect how well a species can adapt to climate change. The shorter the generation time (the time it takes for a species to go from one generation to another), the faster the evolutionary rate. The size of a particular population, the amount of genetic variability it has and the fitness of its individuals are also important variables. Adaptation could conceivably keep pace with climate change in situations where there is less environmental disruption, a good-sized population with genetic variation, short generation times and fit individuals.

For example, the Quino checkerspot butterfly, once common in Southern California, was thought to be at risk of extinction because of climate change and habitat loss. To the surprise of scientists, it adapted by shifting its range to higher ground and finding a completely new plant on which to lay its eggs.

Some corals in Samoa have also shown unexpected resilience in response to higher water temperatures. Scientists believe that natural selection may have favored the most heat-tolerant corals, allowing them to survive and produce more offspring.

While there are numerous examples of nature's resilience, today species also face the human-induced stresses of pollution, invasive species and habitat fragmentation or degradation, which can decrease or isolate populations and inhibit migration, all of which make adaptation more difficult.

Organisms that do not have the phenotypic plasticity or genetic variation that enable them to adapt to changing conditions may well face extinction. For example, the endangered red-cockaded woodpecker, which depends on the longleaf pine forests in the southeast U.S., has not shifted its range north at all. As its habitat changes, scientists do not know if the bird will survive.

Polar bears are at risk because of their long generation times and small populations. According to the National Wildlife Federation, the amount of Arctic sea ice observed in 2012 was 49 percent less than in the 1980s and 1990s. Polar bears need thick near-shore ice on which to hunt seals, but with the sea ice dwindling so rapidly, polar bears must now swim, sometimes as long as 12 days, to reach offshore ice floes, and they often drown. The U. S. Geological Survey projects that two-thirds of the world's polar bear sub-populations will be extinct by 2050.

A National Wildlife Federation report offers a range of recommendations to safeguard wildlife including:

Provide funding to federal and state programs that promote climate science and adaptation.

Make sure that steps taken to reduce carbon emissions minimize impacts on wildlife and their habitats.

Promote climate adaptation plans that enhance natural ecosystems and habitats while providing natural protection against extreme weather events.

Discourage development and infrastructure building in environmentally sensitive areas.

Make room for wildlife to shift their ranges in response to changing climate conditions by expanding parks and refuges and providing connectivity between them.

There are now a number of efforts to preserve larger expanses of land that allow for species to move. Landscapes that run north-south like the Yellowstone-to-Yukon project, a joint U.S. and Canada initiative seeking to preserve wild lands from Yellowstone to the Yukon, would allow organisms to move north to cooler temperatures. East-west landscapes would enable species to move away from the increasingly hot, dry West. The Wildlands Network aims to create four Continental Wildways, large protected areas for wildlife movement across North America.

The Nokuse Plantation in Florida, the largest private conservation project east of the Mississippi, is a strategic link between various tracts of existing protected lands. The Quabbin-to-Cardigan partnership's mission is to preserve 2 million acres of one of the largest areas of intact, ecologically important forest in central New England. And Regional Conservation Partnerships are helping private owners, public organizations and agencies in New England work together to preserve larger and connected areas of land.

Renowned evolutionary biologist E.O. Wilson believes the only way to prevent the sixth mass extinction of life on earth is to set aside half the planet for all the other species. He described his vision this way: "I see a chain of uninterrupted corridors forming, with twists and turns, some of them opening up to become wide enough to accommodate national biodiversity parks, a new kind of park that won't let species vanish."

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Climate Change Poses Challenges to Plants and Animals

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Because of climate change, spring, summer, fall and winter in the temperate zones are all arriving on average 1.7 days earlier than they ever have before. The changing climate with its more extreme weather is affecting many plant and animal species, disturbing their habitat and disrupting ecosystem functioning.

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David Jensen - The Hunga Tonga eruption sparked the highest-altitude lightning ever recorded

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David Jensen - The Hunga Tonga eruption sparked the highest-altitude lightning ever recorded

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The Hunga Tonga eruption sparked the highest-altitude lightning ever recorded

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The plume from the 2022 eruption spawned flashes of lightning that started 20 to 30 kilometers above sea level.

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For my post I found this video of a behind the scenes at the Natural History Museum of Utah. I find it very interesting since it shows the naming schemes for the dinosaurs that are presented while also informing the audience of newly discovered dinosaur information. Also the actor who plays Phil in Modern Family cohosts the video.

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Behind the Scenes in Paleontology! - Throwback with Ty Burrell

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I choose this video for this Padlet post because it Looked very interesting to me. I had a very brief understanding of Super Volcanos before this video. Although I have constantly heard about the one in Yellowstone due to it's relevance and direct impact to the location in which I live. This video brought in a lot of information I would otherwise not have known.

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Supervolcanoes 101 | National Geographic

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When I saw this assignment I knew exactly where to searching. Ted-Ed videos to me are always so informations and amazing. This video is no exception. This video does a very amazing job of explaining volcanic eruptions and presents it in a very easy to understand manner. What I learned most from this video is how many different variations of pressure can cause an eruption

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Volcanic eruption explained - Steven Anderson

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For my post I found this cute Dr.Binocs video that I recently shared with the youth I work with. I think this video does a good job at describing landslides.
-Dolores Paredes Pozas

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LANDSLIDE - The Dr. Binocs Show | Best Learning Videos For Kids | Peekaboo Kidz

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The Grand Canyon and Great Unconformity 

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The Grand Canyon and Great Unconformity 

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This is a video explaining the formation of the Grand Canyon. It talks about the different unconformities and mineral deposition throughout time.
-Jasmine Robbins

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Geology of the Grand Canyon and the Great Unconformity

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Brian Nelson

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Mohammed Alkhaldi

Industrialization  as a result of human civilization, has led to emission of greenhouse gases not only in various parts of the world but also in the area of Utah. In Utah it has been a major concern as its effects are doubling from recent reports seen, majorly due to burning of fossil fuels.
The impact of emission of greenhouse gases include, increased drought in Utah, increased wildfires, and also high temperatures  than before. Therefore, it is a cumulative responsibility of each one of us and various stakeholders to come up and mitigate the issue of greenhouse emission in Utah.

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Human civilization continues to emit greenhouse gases by burning fossil fuels at record levels, causing global warming and therefore disrupting the entire planetary climate system. In fact, the State of Utah is warming twice as fast as the global rate.

As a result, Utah will continue to experience severe droughts, shrinking snowpack, costly wildfires, and extreme heat events. How we collectively respond to climate change today will determine how our families, health, economy, and natural landscapes will be impacted in the future.

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Utah Climate Action Network - Utah Climate Action Network

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How is Utah addressing climate change? What can be done to build a more sustainable and resilient future? The Utah Climate Action Network is ensuring a collaborative response to these questions.​ CLIMATE CHANGE IN UTAH Human civilization continues to emit greenhouse gases by burning fossil fuels at record levels, causing global warming and therefore disrupting [...]

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True origin of oldest evidence of animals

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True origin of oldest evidence of animals

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Scientists have resolved a longstanding controversy surrounding the origins of complex life on Earth. The studies found molecular fossils extracted from 635-million-year-old rocks aren't the earliest evidence of animals, but instead common algae.

Interesting read!

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Two teams of scientists have resolved a longstanding controversy surrounding the origins of complex life on Earth.

The joint studies found molecular fossils extracted from 635-million-year-old rocks aren't the earliest evidence of animals, but instead common algae.

The researchers from The Australian National University (ANU), Max Planck Institute and Caltech say the finding has big implications for our understanding of evolution.

"It brings the oldest evidence for animals nearly 100 million years closer to the present day," Dr Lennart van Maldegem from ANU, co-author author of one study, said.

"We were able to demonstrate that certain molecules from common algae can be altered by geological processes -- leading to molecules which are indistinguishable from those produced by sponge-like animals.

Professor Jochen Brocks, also based at ANU, said the mystery of when our very earliest animal ancestors emerged and became abundant in the oceans has puzzled palaeontologists for more than a century.

"Ten years ago, scientists discovered the molecular fossils of an animal steroid in rocks that were once at the bottom of an ancient sea in the Middle East," Professor Brocks said.

"The big question was, how could these sponges have been so abundant, covering much of the seafloor across the world, but leave no body fossils?"

Dr Ilya Bobrovskiy, lead author of the other study, said the researchers have been able to "solve this mystery."

"While it holds true sponges are the only living organism which can produce these steroids, chemical processes can mimic biology and transform common and abundant algae sterols into 'animal' sterols," he said.

"These molecules can be generated in the lab when simulating geological time and temperatures, but we also showed such processes did happen in ancient rocks."

The two complementary studies have been published in Nature Ecology and Evolution.

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nature; marine biology; animals; geology; earth science; climate; fossils; origin of life; early humans

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True origin of oldest evidence of animals

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Two teams of scientists have resolved a longstanding controversy surrounding the origins of complex life on Earth. The joint studies found molecular fossils extracted from 635-million-year-old rocks aren't the earliest evidence of animals, but instead common algae. The researchers from The Australian National University (ANU), Max Planck Institute and Caltech say the finding has big implications for our understanding of evolution.

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Ancient volcanoes in southwestern Utah unleashed the largest landslides known to science

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Ancient volcanoes in southwestern Utah unleashed the largest landslides known to science

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Lonnie Wadley

Because of years of Geologic mapping in the state of Utah, scientists have been able to identify three massive landslides that happened millions of years ago.  The slides left debris on over 3000 miles, covering 3 counties in Utah.  Bob Beik and his team named the three slides together the Marysvale gravity slide complex.  This is an interesting article I recommend reading.

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The Markagunt Plateau is considered the top step in the Grand Staircase, the landscape that descends from the roof of southwestern Utah into the basement of the Grand Canyon.

Back in the 1970s, students exploring the region discovered what persisted as a geological mystery for decades: Older volcanic rocks covered more recently formed stones on the 11,000-foot plateau.

"What in the world might have happened to produce that? We're talking about milelong blocks of rock that are just out of place," said Bob Biek, a senior scientist with the Utah Geological Survey. "It really breaks a fundamental rule of geology that older rocks are typically overlain by younger rocks unless there's something really weird going on, which, it turns out, there is."

That weird something proved to be ancient "megaslides" that occurred 18 million to 25 million years ago and are far larger than any landslide known to have occurred in the Earth's history, according to ongoing r esearch sponsored by the geological survey and led by Biek. Thanks to years of geologic mapping in southwestern Utah, Biek and his team have identified three massive slides associated with volcanic highlands that have long since eroded away, replaced by today's broad valleys and towering plateaus, like the Markagunt, Sevier Plateau and Black Mountains.

Biek named the three slides after these plateaus, collectively called the Marysvale gravity slide complex, named for the volcanic field that dominated this landscape millions of years ago. Debris from the slides covers 3,000 square miles in Piute, Iron, Garfield and Beaver counties and is a mile thick at its deepest on the southern end of the Tushar Mountains.

Put another way, the slides are almost as large as Yellowstone National Park and the debris could fill the Grand Canyon, according to an article Biek and his colleagues wrote in the latest issue of the Utah Geological Survey's quarterly journal Survey Notes.

Collaborators include Peter Rowley, a retired U.S. Geological Survey geologist, and David Hacker, a geology professor at Kent State University in Ohio.

Landslides typically leave obvious signs on a landscape, but that was not the case with this series of ancient slides.

"It is old. It is deeply eroded and partly buried by younger deposits and cut by later faults," Biek and his colleagues wrote. "The [Marysvale complex] is, by any geologic standard, insanely big - so large that we cannot see it from any single vantage point."

Setting the stage for the slides was a volcanic uplift that had created vast highlands dotted with dozens of stratovolcanoes, like those found in the Cascade Mountains of Oregon and Washington, said Rowley, who was monitoring Mount St. Helens at the time of its 1980 eruption.

That eruption caused Mount St. Helens' summit and north face to collapse in what was among the largest slides in recorded history. Multiply that event by a thousand and you'll get an idea of the Markagunt slide's magnitude.

It was the collapse of Mount St. Helens that helped Biek solve the mystery of the Markagunt Plateau's volcanic rocks.

"It really opened the door to geologists to realize how unstable these volcanoes actually are. Before [Mount St. Helens' eruption], they didn't realize that volcanoes fell down," Biek said. "There's hundreds and hundreds of modern examples of volcanoes that you can see in the landscape today that have collapsed catastrophically. St. Helens is just one of the latest."

Biek first identified the Markagunt slide, the largest of the three, in 2014, and subsequent searching identified the Sevier slide to the east in 2016 and the Black Mountains slide to the west last year.

"These Cascades-like volcanoes were built upon a weak foundation of clay-rich, greasy, unstable rock. Imagine piling volcanoes up. At some point they're going to become unstable and collapse," Biek said. "Likely it was an earthquake or an eruption that triggered each of these three slides."

He believes there could be other massive landslides hiding in plain sight elsewhere in the world.

"These things are so large that they replicate truly tectonic features that we see elsewhere in the landscape," Biek said. "One of the important things is to look at other volcanic fields elsewhere in the western U.S. and elsewhere in the world and see if they actually might host as-yet-unrecognized giant landslides."

Biek believes the Marysvale slides began with the Sevier slide 25 million years ago, followed 2 million years later by the Markagunt slide. The pattern culminated with the Black Mountains slide, following a western direction that tracked the movement of volcanic activity over time in this region where the Great Basin and the Colorado Plateau now meet.

Biek suspects each of the slides, which all moved from north to south, was a single catastrophic event that lasted only minutes. Moving debris reached freeway speeds and would have obliterated everything in their paths. Evidence for such cataclysms was found in the form of a strange rock, known as pseudotachylyte, which the geologists discovered in several places.

"That is melted rock. It is formed by the grinding action of rock against rock," Biek said. "The only way to actually generate enough heat to do that is if you move things very quickly."

What concealed these slides was their sheer size. The Markugunt slide was some 20 miles wide and extended 60 miles.

Rowley, who lives in New Harmony, had mapped the geology of this region for decades, filing about 200 reports during his career.

"I did a lot of the early mapping in the Tushars and I missed it all, the three slides," Rowley said, "I walked over them many times and never saw them. It was too big."

Anyone traveling across southwestern Utah will pass through landscapes shaped by these ancient slides.

"You won't know because they're so big and they don't look like a modern slide. But all the pieces are there," Biek said. "It's interesting just to know about the history of the landscape that you were living on."

Biek is developing a field guide to the slides and hopes to see interpretive signs and trails installed at sites where the public can see evidence of these cataclysmic events. Most of these locations are hard to reach, but one possible spot for interpretive facilities is a road cut near Panguitch Lake, where a millimeter-thick layer of pseudotachylyte is apparent.

"This is an exciting discovery," Rowley said. "The public needs to know this stuff and in a language they understand."

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Ancient volcanoes in southwestern Utah unleashed the largest landslides known to science

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The Markagunt Plateau is considered the top step in the Grand Staircase, the landscape that descends from the roof of southwestern Utah into the basement of the Grand Canyon. Back in the 1970s, students exploring the region discovered what persisted as a geological mystery for decades: Older volcanic rocks covered more recently formed stones on the 11,000-foot plateau.

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The Effects of Air Pollution on Life Expectancy in Utah

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The Effects of Air Pollution on Life Expectancy in Utah

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Brooke Deters
This is an interesting article that covers a study that was conducted by a BYU student that determined that air pollution causes between 2,500 and 8,000 premature deaths each year. They acknowledge that the recent strides to reduce air pollution has helped but they hope to reduce the pollution by 25% by 2026. The pollution also effects mental health and crops. By reducing our pollution levels our state would actually save money. I think its important as citizens to try our best to reduce our carbon footprint by making small changes like carpooling, using public transportation, or using solar to power our homes.

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Utah's poor air quality takes a heavy toll on the state's economy and its residents' longevity, according to research released this week by Brigham Young University.

In the peer-reviewed study, an interdisciplinary research team led by graduate student Isabella Errigo concluded air pollution results in between 2,500 and 8,000 premature deaths each year in Utah, decreasing the median life expectancy by 1.1 to 3.6 years.

"It was a real eye opener to see quantitative estimates of how serious the health and economic costs of air pollution are for the people of Utah," said Errigo, who is pursuing a master's degree in BYU's department of plant and wildlife sciences. "The consequences of dirty air can seem very abstract until you read the medical research connecting the quality of our environment to our personal health."

That move by the EPA recognized the strides Utah has made toward reducing emissions, but officials acknowledge there is still much room for improvement and they seek to reduce emissions by 25% by 2026.

Drawing from contributions of 23 scholars, the BYU study employed an approach called expert assessment, which analyzes all available research and experience from published and unpublished scientific studies. Combining expertise from public health, atmospheric science and economics, the researchers identified the types of disease and economic damage arising from Utah's air pollution and then quantified their impact.

"Utahns understand that air pollution imposes large hidden costs on our communities which is why it's consistently ranked as a top concern," said Mitchell, an atmospheric scientist. "Thankfully, innovation has made clean energy technologies cost competitive on the market, without even considering those hidden costs. The coming energy transition will mean being good stewards of the environment will also protect our economy."

Besides eating away at Utah residents' life expectancy, air pollution also takes a bite out of their pocketbooks.

The researchers assigned economic losses to a range between $750 million and $3.3 billion, mostly stemming from health care expenses, crop damage and lost earning potential, in addition to indirect costs such as loss of tourism, decreased growth and regulatory burdens.

These losses pale in comparison to the $10 million the Utah Legislature appropriated this year toward programs to reduce pollution, suggesting such expenditures could represent a huge return on investment.

"The payoff of reducing pollution would be huge in economic terms and the benefits would be incalculable in terms of human life and health," said senior author Ben Abbott, a BYU professor of ecology. "It's a question of choice. Are we going to settle for incremental progress in air quality or take advantage of this immense opportunity to improve the health of our communities and remove this enormous drag on our economy?"

The Gardner roadmap offered more than 30 recommendations, which the study ranked in terms of their impact. The most effective measures are increasing energy efficiency of vehicles and buildings, promoting awareness, removing subsidies for nonrenewable energy, such as coal and natural gas, requiring industry to pay for the right to pollute, and expanding alternative transportation, such as cycling and public transit. Each of these initiatives could result in double-digit decreases in air pollution, although no single measure could solve the state's air quality problems, the study found.

"In our efforts to clear the air there are no perfect answers, but there are practical solutions," Carter said. "When looking at how poor air quality impacts our region, it is important to know that we are making progress and that each person, family, organization, and community can find ways to reduce emissions and improve our quality of life."

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Study finds air pollution reduces life expectancy in Utah

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Utah's poor air quality takes a heavy toll on the state's economy and its residents' longevity, according to research released this week by Brigham Young University. In the peer-reviewed study, an interdisciplinary research team led by graduate student Isabella Errigo concluded air pollution results in between 2,500 and 8,000 premature deaths each year in Utah, decreasing the median life expectancy by 1.1 to 3.6 years.

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The Importance of Clean Air and the Health of Our Brains.

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The Importance of Clean Air and the Health of Our Brains.

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In Utah, we live in a bowl. Due to this, every winter we can clearly see the inversion. We have bad air during the summers as well, but it's just not as visible.  "“Utah’s mountain valleys and wintertime temperature inversions, combined with emissions, creates unusual chemical and photochemical conditions that lead to the formation of PM2.5,” (DeBry, 2019). KSL We are already aware of the effects of bad air on the human and that it can cause:

Premature death in people with heart or lung disease

Nonfatal heart attacks

Irregular heartbeat

Aggravated asthma

Decreased lung function

Though now studies are linking issues such as Alzheimer's disease found in the brains of children, autism-like social and behavioral issues (lab tests), and that particles from air pollution may also afflict the brain via the bloodstream. Clean are is a global issue. According to the article,  more than 90 percent of people breathe air that fails to meet WHO standards globally.

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A Global Threat

Although the coronavirus disease 2019 (COVID-19) pandemic and associated "shelter in place" policies have reduced fossil fuel use to offer a temporary respite from extreme pollution in some places, most countries face an ongoing epidemic of dirty air as a result of growing urban congestion and an uptick in climate-driven wildfires, among other factors. Indoor air pollution further plagues many of the world's poorest communities. Around 3 billion people cook indoors over open fires or stoves fueled by wood, biomass, kerosene, or coal. In 2018, the World Health Organization (WHO) identified air pollution as the second-largest risk factor for noncommunicable disease worldwide. And the WHO's stats don't include the full range of neurological effects now being discovered, notes neurotoxicologist Deborah Cory-Slechta at the University of Rochester in New York.

Globally, more than 90 percent of people breathe air that fails to meet WHO standards. That includes an estimated four in 10 people in the United States, although efforts such as the US Clean Air Act and its amendments of 1990 have helped. Between 2000 and 2016, the average concentration of particulate matter (PM) with a diameter of less than 2.5 micrometers (PM2.5), tiny particles produced by combustion, fell by around 40 percent in the United States. But the country's overall air quality has worsened since 2016. Partly to blame is a rise in wildfire smoke, which is now responsible for an estimated 40 percent of particulate matter pollution.

Yet cleaner, healthier air remains achievable, notes Dean Schraufnagel, a pulmonologist at the University of Illinois at Chicago. "There are no death certificates that say air pollution exposure," he says. "But we know that air pollution affects every organ in the body. If we stop the air pollution at its source, we can get strikingly important health benefits."

Schraufnagel, also the director of the Forum of International Respiratory Societies, points to one easy target: idling diesel-powered school buses. A 2019 study out of Georgia in the United States found that districts that retrofitted school buses to reduce diesel emissions reported significant increases in students' English test scores as well as smaller improvements in math ( 4).

The havoc air pollution can wreak on the brain is also a new area of interest for Schraufnagel, whose research and clinical practice has long focused on lung disease. Today, he is working with international organizations to get air pollution on the minds of not just pulmonologists but also neurologists and other medical experts. "This should be a call to action," adds Schraufnagel.

Size Matters

Air pollution is a cocktail of suspended gases, solids, and liquid particles. While this mix contains numerous hazardous ingredients, such as ozone, sulfur dioxide, and carbon monoxide, the component that appears most concerning for the brain is PM.

The US Environmental Protection Agency (EPA) regulates PM10 and PM2.5, defined as particles less than 10 and 2.5 micrometers in diameter, respectively. PM2.5, also known as fine particulate matter, generally comes from smoke, dust, and vehicle exhaust. Because PM2.5 is so tiny-30 times smaller than the width of the average human hair-it can remain airborne for long periods of time, infiltrate buildings, and penetrate the body. Ultrafine particles, which measure less than 0.1 micrometer across, may be even worse offenders. Yet the miniscule mass of these particles makes them difficult to monitor. They remain unregulated by the EPA.

Fine and ultrafine particulate matter tends to circumvent the mechanisms that the human body has evolved to deflect, detain, and destroy unwelcome visitors. "The health effects of air pollution are all about particle size," says Cory-Slechta. Studies suggest that these tiny particles can even go up the nose and be carried straight to the brain via the olfactory nerve ( 5)-hence bypassing the blood-brain barrier. And they don't travel alone. On their surfaces these particles carry contaminants, from dioxins and other chemical compounds to metals such as iron and lead. "PM is simply acting as a vector," says Masashi Kitazawa, a molecular neuropathologist at the University of California, Irvine. "It might be a number of chemicals that get into the brain and act in different ways to cause damage."

Because of their large surface area relative to their volume, the smallest particles are the biggest offenders. Cory-Slechta's research has largely focused on lead and mercury, neurotoxic metals that are abundant in air pollution. "Ultrafine particles are like little Trojan horses," she says. "Pretty much every metal known to humans is on these."

Metal-toting particles that reach the brain can directly damage neurons. Both the particles themselves and their toxic hitchhikers can also cause widespread harm by dysregulating the activation of microglia, the immune cells in the brain. Microglia may mistake the intruders for pathogens, releasing chemicals to try to kill them. Those chemicals can accumulate and trigger inflammation. And chronic inflammation in the brain has been implicated in neurodegeneration ( 6).

Particles may also afflict the brain via the bloodstream. Research shows that small particles can slip through the plasma membrane of alveoli-the tiny air sacs in the lungs-and get picked up by capillaries. The particles are then distributed around the body in the blood. Although some of these particles may eventually breach the blood-brain barrier, a pollutant need not enter the brain to cause trouble there. The immune system can react to particles in the lung or bloodstream, too, triggering widespread inflammation that affects the brain.

Even an ingested particle could have indirect neurological effects, via the gut. Researchers now recognize strong connections between the gut microbiome and the brain ( 7), and studies show that delivering fine particles to the gut can cause systemic inflammation ( 8).

A Toxic Turn

In January 2010, Cory-Slechta received a surprising request from some University of Rochester environmental medicine colleagues. Typically, the group researched the effects of air pollution on the lungs and hearts of adult animals. But they had just exposed a group of newborn mice and asked Cory-Slechta's team to look at the brains.

At first she didn't think much of the request. Cory-Slechta was much more concerned about deadly lead exposure in children, her research focus at the time. "I didn't think of air pollution as a big problem for the brain," she says. Then she examined the animals' tissue. "It was eye-opening. I couldn't find a brain region that didn't have some kind of inflammation."

Her team followed up with their own studies. In addition to inflammation, they saw classic behavioral and biochemical features of autism, attention-deficit disorder, and schizophrenia in mice exposed to pollutants during the first days after birth. The mouse brains had noticeably less white matter, particularly in the corpus callosum connecting the right and left cerebral hemispheres. In work published last November, Cory-Slechta's group further linked short-term exposures to air pollution with impaired learning and memory in aged mice, based on measures of spontaneous movement, navigation of a maze, short-term object recognition, and the ability to discriminate odors ( 9). The concentrations of particulate matter used, she notes, "easily include sitting in traffic in major cities."

"We may not know all the details, and very much of the research is incomplete. But incomplete doesn't mean inconclusive."

-Amedeo D'Angiulli

The work adds to a mounting literature on air pollution's unanticipated effects on the brain. Some of the first data came from Mexico City in the early 2000s, shortly after the United Nations declared it the most polluted city on Earth. Those studies identified signs of DNA damage, inflammation, degradation of the blood-brain barrier, and Alzheimer's-type pathology in stray dogs living in the city ( 10, 11).

But many researchers were initially skeptical. Such observational studies could not prove that air pollution caused the neurological changes. Urban dogs encounter many stresses, such as traffic noise, that may correlate with air pollution. For people, potential confounders include access to green space and a range of socioeconomic factors. "To be honest, I didn't believe in the studies," says Amedeo D'Angiulli, a neuroscientist at Carleton University in Ottawa, Ontario, Canada. He adds that he didn't want to believe them: The implications were too frightening.

D'Angiulli later ran into the lead author of those studies, Lilian Calderón-Garcidueñas, at a conference. They then began corresponding via email and she suggested he analyze the data himself. D'Angiulli did. And after he uncovered the same patterns, the two started collaborating on research that not only replicated the previous canine observations, D'Angiulli says, but also suggested that it was more than dogs that were in trouble.

Based on MRI scans, cognitive tests, and measures of inflammatory markers in the blood, the team identified neuroinflammation, brain structure changes, cognitive deficits, and Alzheimer's-like pathologies in apparently healthy children living in Mexico City, compared with a group of similar children in a less polluted city. The findings, according to the authors, suggested that dirty air may spur brain disease at far younger ages than previously suspected ( 12). In a 2018 study, Calderón-Garcidueñas, now a toxicologist at the University of Montana in Missoula, found above-normal levels of both amyloid and tau proteins in more than 99 percent of autopsies conducted on 203 city residents-one just 11 months old.

Other epidemiological studies have strengthened the connection by looking at the relationship between the exposure dose and the resulting risk. Research in Ontario, Canada, found that living farther away from a major road lowered the risk of developing dementia ( 13). A study of nearly 3,000 Barcelona schoolchildren found that those attending schools with more traffic pollution had slower cognitive development ( 14). And in the United States, a study found that living in locations where ambient particulate matter exceeded EPA recommendations nearly doubled women's risk of developing dementia. When those researchers looked specifically at older women with two copies of the APOE4 gene variant, a strong genetic factor for Alzheimer's disease, the dementia risk associated with living in those locations jumped almost threefold ( 2).

Catching Air

Still, controlled studies in animals provide some of the strongest and most detailed evidence of air pollution's impacts. Many of these studies use ambient air from polluted environments to simulate real-world exposure-researchers are gathering air particles near roadways, harbors, oil refineries, and traffic tunnels.

Pamela Lein took the unusual step of bringing her research animals to the source. The molecular biologist at the University of California, Davis, recently spent two years converting a single-wide trailer into a vivarium that now sits adjacent to a traffic tunnel in northern California.

A system of ducts pulls air from the tunnel directly into the trailer, which holds 216 rodent cages. Some of the animals in Lein's studies receive air straight from the tunnel to experience daily and seasonal fluctuations in gases and particulate matter, along with the traffic vibrations and noise. Another group of animals breathes filtered, clean air but is exposed to the same vibration and noise, while a third group-back at a lab on campus-gets clean air, peace, and quiet. The arrangement allows the researchers to separate any potential effects of vibration and noise from those of the pollution as they look for effects on the brain and behavior over several months.

Although Lein's findings are not yet published, she reports "remarkable changes" in the brains of rat pups exposed to traffic-related air pollution throughout gestation and nursing, including an excess of new neurons forming in the developing brain. (Too many neurons can be just as detrimental to brain function as too few, she notes.) After lifelong exposures, older rats showed behavioral deficits, losses of synapses-the junctions between nerve cells-and earlier and larger growth of amyloid plaques.

Neurobiologist Caleb Finch, at the University of Southern California in Los Angeles, and behavioral neuroscientist Ben Nephew, at the Worcester Polytechnic Institute in MA, are producing similarly concerning results in the rodent brain. They're seeing reduced adult nerve stem cell production and inflammatory responses that speed up the production of amyloid plaques. Their animals also show decreased play behavior and social grooming and increased anxiety-related behaviors ( 15). Costa's team has found that mice exposed to diesel exhaust during prenatal and early postnatal life have lower levels of reelin, a protein important for brain development, as well as morphological changes in the layering of the cortex ( 16). "That is very similar to what you find in autism," he says.

Saving Minds and Money

Nicolai Kuminoff, an environmental economist at Arizona State University (ASU) in Tempe, had spent much of his career thinking about the benefits of reducing air pollution. Yet, again, impacts on the brain hadn't been a top priority until he saw the emerging animal and epidemiological studies. He and some ASU colleagues believed insights from economic studies could build on that work.

They recently leveraged a natural experiment to seek evidence of a causal relationship between air pollution and dementia in humans ( 17). In the mid-2000s, the EPA began to enforce a maximum PM2.5 threshold around the country. Local regulators in many areas were forced to improve air quality. In areas where pollution levels were just below the threshold, however, no cleanup was required.

Epidemiological studies can face a major limitation: People often end up living in more or less polluted areas as a result of factors such as education and income that might also influence health outcomes. The team sidestepped that issue by taking advantage of these resulting higher and lower exposure groups, connecting EPA air quality data to Medicare data for nearly 7 million Americans between 2004 and 2013. They wanted to know whether cutting air pollution could reduce rates of dementia.

After controlling for a range of health and socioeconomic factors, including hypertension, education, and housing values, they found that relatively fewer older people in counties with newly improved air quality developed dementia compared with counties without recent changes. Overall, evidence linked the federal regulation to nearly 182,000 fewer people with dementia in 2013. The team calculated that reduction to be worth an estimated $214 billion based on assumptions about the value of life and health. They further determined that additional regulation would avoid even more cases of dementia. In fact, dropping air pollution in areas with lower initial concentrations produced some of the largest risk reductions, notes Kuminoff.

The federal government has been incorporating a value for improving health into its cost-benefit calculations for avoided cases of asthma and heart disease but has not yet accounted for the link between air pollution and dementia. The EPA doesn't cite the impact of air pollution on the brain, nor do US regulations such as the 2015 Clean Power Plan. "We've almost entirely ignored the brain," says Finch. Shifting Alzheimer's disease onset earlier by a year or two, he adds, "could be an immense cost."

He and other researchers continue to explore many unanswered questions, such as which pollutants or hitchhiking metals are the most potent in damaging the brain and whether there are developmental windows of higher susceptibility. Gender may play a role, too: Cory-Slechta has found that exposures after birth cause far more change in the brains of male mice than females.

Kuminoff and his colleagues are now investigating how impacts of air pollution on the brain vary across regions of the country and demographic groups. The particulate matter contaminating East Coast air is predominantly generated by coal and natural gas, for example, whereas manufacturing and motor vehicle traffic contribute more particles to the air in the West Coast. "One possibility is that it's not the size of particulates but what's in it that matters most," Kuminoff says. His team is also asking questions such as whether someone could reverse the effects of their exposure if they move from a place with dirty air to a cleaner area-similar to quitting smoking-or whether air pollution may play a role in the persistence of socioeconomic status across generations. Damage to the brain at an early age, explains Kuminoff, may cause a downward spiral of poor education and income that pushes people to stay in polluted areas throughout their lives.

Everyone seems to agree that although the research remains at an early stage, enough evidence exists now to take action. "We may not know all the details, and very much of the research is incomplete. But incomplete doesn't mean inconclusive," says D'Angiulli.

View Abstract

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News Feature: How air pollution threatens brain health

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Long thought to primarily harm the lungs and cardiovascular system, air pollution is now catching the attention of neuroscientists and toxicologists. The buzz of a leaf blower and its gaseous fumes fill the air outside a lab facility at the University of Washington in Seattle.

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My padlet is on Natural hazards in regards to what an earthquake is: An earthquake is caused by a sudden slip on a fault. The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel. Aftershocks are a sequence of earthquakes that happen after a larger mainshock on a fault. Aftershocks occur near the fault zone where the mainshock rupture occurred and are part of the "readjustment process” after the main slip on the fault. They can become less frequent with time, and can continue for days, weeks, and even months.

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What Is An Earthquake? | The Dr. Binocs Show | Educational Videos For Kids

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It's good to get all the facts and not allow fear to rule us when it comes to climate change, politics, pandemics, etc...

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Climate scientists are speaking out against grossly exaggerated claims about global warming.
Getty

Environmental journalists and advocates have in recent weeks made a number of apocalyptic predictions about the impact of climate change. Bill McKibben suggested climate-driven fires in Australia had made koalas "functionally extinct." Extinction Rebellion said "Billions will die" and "Life on Earth is dying." Vice claimed the "collapse of civilization may have already begun."

Few have underscored the threat more than student climate activist Greta Thunberg and Green New Deal sponsor Rep. Alexandria Ocasio-Cortez. The latter said, "The world is going to end in 12 years if we don't address climate change." Says Thunberg in her new book, "Around 2030 we will be in a position to set off an irreversible chain reaction beyond human control that will lead to the end of our civilization as we know it."

Sometimes, scientists themselves make apocalyptic claims. "It's difficult to see how we could accommodate a billion people or even half of that," if Earth warms four degrees, said one earlier this year. "The potential for multi-breadbasket failure is increasing," said another. If sea levels rise as much as the Intergovernmental Panel on Climate Change predicts, another scientist said, "It will be an unmanageable problem."

Apocalyptic statements like these have real-world impacts. In September, a group of British psychologists said children are increasingly suffering from anxiety from the frightening discourse around climate change. In October, an activist with Extinction Rebellion ("XR") - an environmental group founded in 2018 to commit civil disobedience to draw awareness to the threat its founders and supporters say climate change poses to human existence - and a videographer, were kicked and beaten in a London Tube station by angry commuters. And last week, an XR co-founder said a genocide like the Holocaust was "happening again, on a far greater scale, and in plain sight" from climate change.

Climate change is an issue I care passionately about and have dedicated a significant portion of my life to addressing. I have been politically active on the issue for over 20 years and have researched and written about it for 17 years. Over the last four years, my organization, Environmental Progress, has worked with some of the world's leading climate scientists to prevent carbon emissions from rising. So far, we've helped prevent emissions increasing the equivalent of adding 24 million cars to the road.

I also care about getting the facts and science right and have in recent months corrected inaccurate and apocalyptic news media coverage of fires in the Amazon and fires in California, both of which have been improperly presented as resulting primarily from climate change.

Journalists and activists alike have an obligation to describe environmental problems honestly and accurately, even if they fear doing so will reduce their news value or salience with the public. There is good evidence that the catastrophist framing of climate change is self-defeating because it alienates and polarizes many people. And exaggerating climate change risks distracting us from other important issues including ones we might have more near-term control over.

I feel the need to say this up-front because I want the issues I'm about to raise to be taken seriously and not dismissed by those who label as "climate deniers" or "climate delayers" anyone who pushes back against exaggeration.

With that out of the way, let's look whether the science supports what's being said.

First, no credible scientific body has ever said climate change threatens the collapse of civilization much less the extinction of the human species. "'Our children are going to die in the next 10 to 20 years.' What's the scientific basis for these claims?" BBC's Andrew Neil asked a visibly uncomfortable XR spokesperson last month.

"These claims have been disputed, admittedly," she said. "There are some scientists who are agreeing and some who are saying it's not true. But the overall issue is that these deaths are going to happen."

"But most scientists don't agree with this," said Neil. "I looked through IPCC reports and see no reference to billions of people going to die, or children in 20 years. How would they die?"

"Mass migration around the world already taking place due to prolonged drought in countries, particularly in South Asia. There are wildfires in Indonesia, the Amazon rainforest, Siberia, the Arctic," she said.

But in saying so, the XR spokesperson had grossly misrepresented the science. "There is robust evidence of disasters displacing people worldwide," notes IPCC, "but limited evidence that climate change or sea-level rise is the direct cause"

What about "mass migration"? "The majority of resultant population movements tend to occur within the borders of affected countries," says IPCC.

It's not like climate doesn't matter. It's that climate change is outweighed by other factors. Earlier this year, researchers found that climate "has affected organized armed conflict within countries. However, other drivers, such as low socioeconomic development and low capabilities of the state, are judged to be substantially more influential."

Last January, after climate scientists criticized Rep. Ocasio-Cortez for saying the world would end in 12 years, her spokesperson said "We can quibble about the phraseology, whether it's existential or cataclysmic." He added, "We're seeing lots of [climate change-related] problems that are already impacting lives."

That last part may be true, but it's also true that economic development has made us less vulnerable, which is why there was a 99.7% in the death toll from natural disasters since its peak in 1931.

In 1931, 3.7 million people died from natural disasters. In 2018, just 11,000 did. And that decline occurred over a period when the global population quadrupled.

What about sea level rise? IPCC estimates sea level could rise two feet (0.6 meters) by 2100. Does that sound apocalyptic or even "unmanageable"?

Consider that one-third of the Netherlands is below sea level, and some areas are seven meters below sea level. You might object that Netherlands is rich while Bangladesh is poor. But the Netherlands adapted to living below sea level 400 years ago. Technology has improved a bit since then.

What about claims of crop failure, famine, and mass death? That's science fiction, not science. Humans today produce enough food for 10 billion people, or 25% more than we need, and scientific bodies predict increases in that share, not declines.

The United Nations Food and Agriculture Organization (FAO) forecasts crop yields increasing 30% by 2050. And the poorest parts of the world, like sub-Saharan Africa, are expected to see increases of 80 to 90%.

Nobody is suggesting climate change won't negatively impact crop yields. It could. But such declines should be put in perspective. Wheat yields increased 100 to 300% around the world since the 1960s, while a study of 30 models found that yields would decline by 6% for every one degree Celsius increase in temperature.

Rates of future yield growth depend far more on whether poor nations get access to tractors, irrigation, and fertilizer than on climate change, says FAO.

All of this helps explain why IPCC anticipates climate change will have a modest impact on economic growth. By 2100, IPCC projects the global economy will be 300 to 500% larger than it is today. Both IPCC and the Nobel-winning Yale economist, William Nordhaus, predict that warming of 2.5°C and 4°C would reduce gross domestic product (GDP) by 2% and 5% over that same period.

Does this mean we shouldn't worry about climate change? Not at all.

One of the reasons I work on climate change is because I worry about the impact it could have on endangered species. Climate change may threaten one million species globally and half of all mammals, reptiles, and amphibians in diverse places like the Albertine Rift in central Africa, home to the endangered mountain gorilla.

But it's not the case that "we're putting our own survival in danger" through extinctions, as Elizabeth Kolbert claimed in her book, Sixth Extinction. As tragic as animal extinctions are, they do not threaten human civilization. If we want to save endangered species, we need to do so because we care about wildlife for spiritual, ethical, or aesthetic reasons, not survival ones.

And exaggerating the risk, and suggesting climate change is more important than things like habitat destruction, are counterproductive.

For example, Australia's fires are not driving koalas extinct, as Bill McKibben suggested. The main scientific body that tracks the species, the International Union for the Conservation of Nature, or IUCN, labels the koala "vulnerable," which is one level less threatened than "endangered," two levels less than "critically endangered," and three less than "extinct" in the wild.

Should we worry about koalas? Absolutely! They are amazing animals and their numbers have declined to around 300,000. But they face far bigger threats such as the destruction of habitat, disease, bushfires, and invasive species.

Think of it this way. The climate could change dramatically - and we could still save koalas. Conversely, the climate could change only modestly - and koalas could still go extinct.

The monomaniacal focus on climate distracts our attention from other threats to koalas and opportunities for protecting them, like protecting and expanding their habitat.

As for fire, one of Australia's leading scientists on the issue says, "Bushfire losses can be explained by the increasing exposure of dwellings to fire-prone bushlands. No other influences need be invoked. So even if climate change had played some small role in modulating recent bushfires, and we cannot rule this out, any such effects on risk to property are clearly swamped by the changes in exposure."

Nor are the fires solely due to drought, which is common in Australia, and exceptional this year. "Climate change is playing its role here," said Richard Thornton of the Bushfire and Natural Hazards Cooperative Research Centre in Australia, "but it's not the cause of these fires."

The same is true for fires in the United States. In 2017, scientists modeled 37 different regions and found "humans may not only influence fire regimes but their presence can actually override, or swamp out, the effects of climate." Of the 10 variables that influence fire, "none were as significant... as the anthropogenic variables," such as building homes near, and managing fires and wood fuel growth within, forests.

Climate scientists are starting to push back against exaggerations by activists, journalists, and other scientists.

"While many species are threatened with extinction," said Stanford's Ken Caldeira, "climate change does not threaten human extinction... I would not like to see us motivating people to do the right thing by making them believe something that is false."

I asked the Australian climate scientist Tom Wigley what he thought of the claim that climate change threatens civilization. "It really does bother me because it's wrong," he said. "All these young people have been misinformed. And partly it's Greta Thunberg's fault. Not deliberately. But she's wrong."

But don't scientists and activists need to exaggerate in order to get the public's attention?

"I'm reminded of what [late Stanford University climate scientist] Steve Schneider used to say," Wigley replied. "He used to say that as a scientist, we shouldn't really be concerned about the way we slant things in communicating with people out on the street who might need a little push in a certain direction to realize that this is a serious problem. Steve didn't have any qualms about speaking in that biased way. I don't quite agree with that."

Wigley started working on climate science full-time in 1975 and created one of the first climate models (MAGICC) in 1987. It remains one of the main climate models in use today.

"When I talk to the general public," he said, "I point out some of the things that might make projections of warming less and the things that might make them more. I always try to present both sides."

Part of what bothers me about the apocalyptic rhetoric by climate activists is that it is often accompanied by demands that poor nations be denied the cheap sources of energy they need to develop. I have found that many scientists share my concerns.

"If you want to minimize carbon dioxide in the atmosphere in 2070 you might want to accelerate the burning of coal in India today," MIT climate scientist Kerry Emanuel said.

"It doesn't sound like it makes sense. Coal is terrible for carbon. But it's by burning a lot of coal that they make themselves wealthier, and by making themselves wealthier they have fewer children, and you don't have as many people burning carbon, you might be better off in 2070."

Emanuel and Wigley say the extreme rhetoric is making political agreement on climate change harder.

"You've got to come up with some kind of middle ground where you do reasonable things to mitigate the risk and try at the same time to lift people out of poverty and make them more resilient," said Emanuel. "We shouldn't be forced to choose between lifting people out of poverty and doing something for the climate."

Happily, there is a plenty of middle ground between climate apocalypse and climate denial.

... Read More

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Why Apocalyptic Claims About Climate Change Are Wrong

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Environmental journalists and advocates have in recent weeks made a number of apocalyptic predictions about the impact of climate change. Bill McKibben suggested climate-driven fires in Australia had made koalas "functionally extinct." Extinction Rebellion said "Billions will die" and "Life on Earth is dying." Vice claimed the "collapse of civilization may have already begun."

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An inconvenient geological truth is staring at the Intermountain West. One of its most densely populated metropolitan area happens to also be its most seismically unstable, raising the possibility - some would say inevitability - of catastrophic loss of life and economic upheaval in the event of a major earthquake.

A network of fissures, known as the Wasatch fault zone, runs 220 miles from central Utah north along the Wasatch Front through Salt Lake City into Idaho, a region with as many as 185,000 homes and other structures built of unreinforced masonry, a construction type prone to crumbling when the earth moves. Last month's magnitude 5.7 temblor was but a mild taste of what could happen.

Now the Utah Geological Survey has released a new report after four years of study, mapping the myriad Wasatch Front faults capable of surface rupture, the kind of seismic movements that can damage buildings and infrastructure.

The Wasatch fault zone is comprised of 10 segments - from Malad, Idaho, to Fayette, Utah. The new study expands the length of surface-rupture faults that are mapped by 64% - from 451 miles to 739 miles, with the biggest gains notched for the Provo, Salt Lake City and Weber segments. Researchers emphasized their findings do not indicate an increase in earthquake risk.

"What has changed is our resolution of the faults and our ability to more closely see the smaller portions of the fault zones or systems," said Nathan Schwebach, spokesman for the Department of Natural Resources. "It's kind of like our human circulatory system. The circulatory system includes large arteries and smaller veins. Yet it's one system. Because of this research, we have now been able to zoom in more closely on smaller sections of the [Wasatch Front] fault systems, which significantly improves our understanding of the entire zone."

The study harnessed airborne light detection and ranging (or lidar) elevation data to improve the accuracy, resolution and detail of current fault maps.

"As a result of this research, we better understand where we've had surface-rupturing earthquakes in the geologic past, and where we may have them in the future. Knowing where fault scarps are present helps us make better land use decisions now and in the future," said UGS hazards geologist Emily Kleber, a co-author of the report. "This new study provides detailed fault mapping and delineates 'special study zones' for the Wasatch fault zone from southern Idaho to central Utah."

"We can wipe away all the trees and buildings from the data so we can just see the surface without distractions," Kleber said. "We can calculate the slope and see subtle changes in the slope."

The new study also helped locate previously unmapped fault traces and find potential sites for future investigations into earthquakes that occurred in the distant past, known as paleoseismic events. These investigations should be pursued "in areas that are being rapidly developed or are in areas lacking good earthquake timing and recurrence information," the report recommends.

The special study zones and fault mapping will soon be available on a hazards app that the UGS is beta testing. The agency has already posted an interactive map illustrating faults and folds that produced earthquakes exceeding magnitude 6.5 over the Quaternary Period, which covered the past 2.6 million years. These geological structures are those that are most likely to produce large quakes in the future.

Not covered in the study is the fault that shifted near Magna on March 18, damaging dozens of homes and scores of historic buildings. That quake and a previous temblor in the same area in 1962 were not strong enough to breach the surface, so that fault remains hidden underground.

While the new lidar-based study helps pin down fault locations, it lacks the precision necessary to determine where it's best to safely site buildings on specific lots.

"While we recommend additional site-specific investigation prior to building," UGS hazards geologist Greg McDonald said, "it's up to local agencies to regulate development within our delineated special study zones."

The study proposes special study areas around fault traces to look for ground cracking, tilting, and minor faulting that usually accompany surface ruptures, according the UGS. This zone of deformation occurs adjacent to the main fault scarp and can extend hundreds of feet, mostly on the "downthrown," or valley side of the fault.

"Those are red flag areas," Kleber said, "that we suggest cities ask for extra studies be done."

Researchers also tapped an archive of historical aerial photographs. Many of these pictures were shot in the early 1970s, predating much of the residential and commercial development now filling the fault zone. Aerials of the Salt Lake Valley date back to 1936.

"These photographs were most useful for mapping in urban areas, where surface fault traces have been obscured by modern ground disturbance," the report states.

To complete the study, Salt Lake County and it cities, along with the Utah Division of Emergency Management, helped pay for a massive data-acquisition effort in 2014. The Utah Geological Survey teamed with the U.S. Geological Survey to hire a plane and conduct overflights, photographing the fault zones with a laser camera. Kleber said they covered 3,000 square miles and recorded 40 billion lidar points.

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Weeks after big earthquake, Wasatch fault system comes into sharper focus, thanks to new study

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An inconvenient geological truth is staring at the Intermountain West. One of its most densely populated metropolitan area happens to also be its most seismically unstable, raising the possibility - some would say inevitability - of catastrophic loss of life and economic upheaval in the event of a major earthquake.

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Utah soon may have a park that pays tribute to one of the state's most notorious killers.

Relax, though, this fleet-footed slasher hasn't been around for millions of years.

But Utahraptor State Park soon could be born, under a proposal expected to be unveiled this week.

It would become Utah's 45th state park, designed to protect the Dalton Wells Quarry, which yielded the first fossils of Utahraptor, Utah's official dinosaur, and many other species unique to Grand County.

Located about 15 miles north of Moab in a part of the state where there are few developed destinations celebrating Utah's rich fossil record, Dalton Wells has since fallen into neglect and now gets more attention from vandals than from paleontologists. The park proposal, the subject of legislation filed last week as an unnumbered bill, enjoys the full support of Grand County leaders, who have long looked for ways to safeguard the quarry and surrounding state-owned lands in the face of relentless vandalism and unregulated recreational use.

"Creating a state park will accomplish Grand County's goals by protecting this valuable area while maintaining recreational opportunities," the council wrote in a Feb. 4 letter to Gov. Gary Herbert. "We look forward to working with the state of Utah to bring this state park to fruition."

State Paleontologist Jim Kirkland considers Dalton Wells the most important dinosaur site in the United States because of its massive deposits of dinosaur bones from at least 10 species found nowhere else in North America.

"It's a gold mine of new dinosaurs. There are 30 that we know are only in Moab Valley," Kirkland said. "Dalton Wells has more kinds of dinosaurs than Dinosaur National Monument " in northeastern Utah.

The size and shape of the park - and what amenities it would host - have yet to be determined. The land, sandwiched between U.S. Highway 191 and Arches National Park, is crisscrossed with motorized and mountain bike trails and is heavily used for dispersed camping. Consequently, the area has become a breeding ground for "Charmin's lily," a truly noxious and invasive species comprised of toilet paper and human excrement.

It also is the site of a historic Civilian Conservation Corps work camp that served as the Moab Isolation Center, a facility for "relocating" Japanese-American internees during World War II.

"It has a whole variety of things that would make it a phenomenal park area," said Hayes, who died in 2018. His successor, Jeff Rasmussen, deferred queries about the newly planned state park to the Department of Natural Resources.

"We're very early in the process. The divisions of Parks and Recreation; Forestry, Fire and State Lands; and the Utah Geological Survey are exploring possibilities, and discussing scenarios with other landowners like SITLA," DNR spokesman Nathan Schwebach said. "As tourism in Utah expands, more recreation facilities are needed, particularly in southeastern Utah. The Dalton Wells/Willow Springs area is popular but [needs] infrastructure to support the demand. With some planning, we can better care for the area while maintaining its recreational value."

Southern Utah abounds in fossils spanning much of dinosaurs' 185-million-year existence, but it lacks much in the way of interpretive destinations for those interested in paleontology.

The sponsor of the legislation calling for a park at Dalton Wells will be Rep. Steve Eliason, R-Sandy, a veteran of two previous efforts to designate new state parks, one at San Rafael Swell and another at Little Sahara Sand Dunes. Neither park came to be, most likely because they were proposed on federal land, which would have required complicated land swaps or land-use agreements with the BLM.

Dalton Wells, by contrast, is on a large block of state-owned land that has become ever more popular among those seeking to avoid the crowds at Moab's usual hot spots. The state block spans Willow Springs Road, once used as Arches' original entrance, and is just south of Klondike Bluffs, a mountain biking magnet developed on federal land during the past decade. The BLM is planning to put an end to dispersed camping there and designate campsites.

The Dalton Wells Quarry is on a 2,000-acre parcel, shaped like the numeral 7, overseen by the Utah Division of Forestry, Fire and State Lands, surrounded by land held by SITLA. Neither agency is equipped to run a park. Some trust lands would need to be incorporated into the park, but SITLA, by law, cannot give away its holdings, even for the most laudable uses. The agency, which manages lands to raise money for public education, would have to be fairly compensated.

To that end, state officials are busy identifying state sovereign lands elsewhere in Grand County that can be traded for trust lands near the dinosaur quarry, according to SITLA Director David Ure.

"We are trying to make the trade to make this park possible. We are working with our sister agencies to determine what is beneficial for them and is beneficial for us," Ure said. "There are some grounds that they have that are important to us. We think the majority would be within a 10-mile radius. That's as close as I can tell you until we have the appraisals."

Dalton Wells is one of three quarries rimming Arches - the others are Gaston and Stikes - that have produced countless pieces of Utahraptor, a small feathered predator that hunted in packs, as well as many other dinosaur species.

The fossils, found in the lower reaches of the Cedar Mountain Formation, date to 125 million to 135 million years ago, marking the early Cretaceous Period. Brigham Young University has conducted most of the groundbreaking excavations at Dalton Wells and some of the bones are housed in its collections in Provo, but many others have left the state.

The site has not been actively excavated for authorized science in several years. As the area between Klondike Bluffs and Willow Springs becomes more popular for recreation, more people are clambering around the Dalton Wells Quarry in search of souvenirs.

"It's a famous site," Kirkland said. "People go up and dig scratch holes. They are curious. They aren't looking to get rich on the black market."

Some have proposed covering the quarry with chain-link fences and burying it to keep the fossils safe, but Kirkland fears such a move would discourage future study and public enjoyment.

"Our communities should see long-term benefits from these resources," Kirkland said, "and long-term benefit for a scientist is interpretation."

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Proposed state park would pay tribute to Utah's dinosaurs

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Utah soon may have a park that pays tribute to one of the state's most notorious killers. Relax, though, this fleet-footed slasher hasn't been around for millions of years. But Utahraptor State Park soon could be born, under a proposal expected to be unveiled this week.

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Two years ago, Alan Titus was prospecting for fossils on Utah's Kaiparowits Plateau, searching for new places to unearth paleontological treasures that could reveal secrets about massive and long-extinct land reptiles known as dinosaurs.

Protruding from sandstone he saw some vertebrates, not an uncommon sight in this corner of the Grand Staircase-Escalante National Monument that has become renowned as one of the world's most productive repositories of dinosaur bones dating to the Cretaceous.

But over the next several months of excavation, what Titus, the monument's resident paleontologist, and colleagues from the Natural History Museum of Utah found was anything but common.

Coming into focus was a well-articulated, nearly complete tyrannosaur, the notorious flesh-ripping, tiny-armed predator.

"It looks like we have the entire skull and most of the body," said Randy Irmis, the museum's paleontology curator. "The back part of tail is missing and a few toes. We don't know yet if the arms are there."

On Sunday, Titus and museum staffer Tylor Birthisel deployed a helicopter to extract the specimen. It was encased in plaster and flown out in pieces, the largest weighing nearly a ton, for shipment to Salt Lake City.

So far, it appears to be 80 percent intact, the most complete tyrannosaur ever recovered in the American Southwest.

Researchers believe the specimen is a teratophoneus, a relative of T. rex that stood about 12 feet tall and roamed the Earth several million years before its more famous cousin.

The genus name means "monstrous murderer" and was first characterized by Thomas Carr and Thomas Williamson in 2011. The species has been found only in the Grand Staircase.

"This discovery exemplifies the uniqueness of the fossils in the the Staircase," Irmis said. "Regardless if it's a teratophoneus or something new, these are things found only in Grand Staircase. These are world-class paleontological resources."

That part of the Grand Staircase also contains 9 billion tons of another extractable resource: high-quality, low-sulphur coal.

Interior Secretary Ryan Zinke's undisclosed monument-reduction recommendations are believed to call for pulling the Kaiparowits out of the monument. A leaked memo to President Donald Trump indicates Zinke wants to shrink Grand Staircase, Bears Ears and two other Western monuments, but it does not provide specifics.

Titus's specimen was embedded in the famed Kaiparowits Formation, a layer of sandstone 2,800 feet thick deposited 76 million to 74 million years ago, just 7 million years before an astroid wiped out most large-bodied animals on Earth.

The discovery could advance dinosaur science because the bones are still together, as if the animal was preserved in the very position in which it died.

"A lot of the bones are articulated. A few things are out of place, but most [of it] is in a life position," Irmis said. "In fossil records carnivores are rarer than herbivores. These apex predators are the rarest because they are at the top of the food chain."

It is unusual to find much of any single dinosaur since so many things can destroy bones over the course of time, including decay, scavengers, weather and geologic forces. This specimen was in the early stages of being exposed when Titus spotted it.

"It has to be exposed for us to find it but not so much that erosion destroys it," Irmis said. He said he believes the dinosaur's carcass was buried in a river channel or in a flooding event.

"We still have to do more geological work to figure which it is," he said.

The find is fortuitous because the museum has specimens representing adult and young teratophoneus. This one, about 17 feet to 20 feet in length, is a juvenile, giving researchers a more complete picture of the creature.

"It can tell us how they change as they grow older," Irmis said. "Having a complete skeleton helps answers those questions."

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Nearly complete tyrannosaur fossil airlifted from Utah's Grand Staircase

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Two years ago, Alan Titus was prospecting for fossils on Utah's Kaiparowits Plateau, searching for new places to unearth paleontological treasures that could reveal secrets about massive and long-extinct land reptiles known as dinosaurs.

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Two earth scientists offered a new model to explain destructive activity in 2018, but a number of their colleagues aren't buying it.

Lava flowing from a fissure in the Leilani Estates neighborhood near Pahoa, Hawaii, in July 2018. Credit... U.S. Geological Survey, via Associated Press

The study's authors, Jamie Farquharson and Falk Amelung, both earth scientists at the University of Miami, note that 60 percent of the volcano's eruptions since 1790 have occurred during the area's shorter rainy season rather than its dry season. That makes them suspect that rainfall has played a key role in triggering not just the 2018 eruption, but also many throughout its history.

But many other scientists aren't buying it.

There are known cases where environmental changes around a volcano affect its eruptive activity. Evidence suggests that big earthquakes, for example, can trigger eruptions but perhaps only if the volcano is primed to erupt. There is also tentative evidence that rainfall could trigger small earthquakes along some faults.

And the notion that water accumulating in rock cavities can destructively forge new corridors for magma isn't unreasonable either, said Michael Manga, a geoscientist at the University of California, Berkeley, who wasn't involved with the study but wrote a perspective piece accompanying the paper. That's the basic principle of hydraulic fracturing, where pressurized fluids are injected underground to break rocks open and liberate their fossil fuel contents.

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A small pond of green water at the lowest point of Kilauea's Halemaʻumaʻu Crater in August. Credit... S. Conway/U.S. Geological Survey Hawaiian Volcano Observatory, via Associated Press

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Did Heavy Rain Make Hawaii's Kilauea Volcano Erupt?

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Two earth scientists offered a new model to explain destructive activity in 2018, but a number of their colleagues aren't buying it. The study's authors, Jamie Farquharson and Falk Amelung, both earth scientists at the University of Miami, note that 60 percent of the volcano's eruptions since 1790 have occurred during the area's shorter rainy season rather than its dry season.

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The eruption on May 18, 1980, was unique for exploding in two ways, a lateral blast plus a column of volcanic ash that went 80,000 feet into the sky. Credit... Corbis, via Getty Images

It's been 40 years since the sideways explosion that changed volcanology forever.

The eruption on May 18, 1980, was unique for exploding in two ways, a lateral blast plus a column of volcanic ash that went 80,000 feet into the sky. Credit... Corbis, via Getty Images

The eruption also showed how much more the contiguous United States needed to prepare for volcanic activity. While the country has 161 geologically active volcanoes, 10 percent of Earth's total, only a handful on Alaskan islands and the Hawaiian archipelago made shows of force in modern history. Many Americans had forgotten about or remained unaware of the active but quiescent volcanoes of the Cascades, the mountainous spine snaking up the West Coast, said Jackie Caplan-Auerbach, a geophysicist at Western Washington University.

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A geologist stood in an 18-inch-deep trench cut into the ash left by Mount St. Helens's eruption on Coldwater Ridge, Wash. Credit... Smith Collection/Gado, via Getty Images

Smoke and ash poured from Mount St. Helens on April 10, 1980, about a month before the historic eruption. Credit... Jack Smith/Associated Press

Downed trees in Washington State on May 23. Credit... John Barr/Liaison, via Getty Images

Dr. Johnston, seeing the north face fall from Coldwater II, jumped on the radio. "Vancouver! Vancouver! This is it!" he cried. Moments later, the blast engulfed the 30-year-old scientist. On another ridge two miles behind him, Gerry Martin, an amateur radio operator who was observing the volcano for the Washington Department of Emergency Services, saw the annihilation of Coldwater II. His last words were: "It's going to get me, too."

By day's end, the storm subsided. A 2.2-mile-long hole now adorned the volcano. Although 57 people, and countless wildlife, had perished, some managed to survive: a few fishermen jumped into rivers to evade the conflagration; a family of hikers were serendipitously shielded by another mountain between them and the volcano.

It could have been worse. As the volcano's activity ramped up in March, scientists had to continually persuade the authorities to restrict access to all but law enforcement, volcano monitoring teams and other essential staff. Some groups protested, in an echo of events now occurring during the coronavirus pandemic, pointing to the impact the no-go zones were having on the local economy. If it wasn't for the vigilance and insistence of scientists such as Dr. Johnston, the death toll could have been in the thousands.

Ash clouds over from the eruption at Ephrata Municipal Airport in Washington on May 19. Credit... Mike Cash/Associated Press

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The Mount St. Helens Eruption Was the Volcanic Warning We Needed

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It's been 40 years since the sideways explosion that changed volcanology forever. The eruption on May 18, 1980, was unique for exploding in two ways, a lateral blast plus a column of volcanic ash that went 80,000 feet into the sky. Credit...

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Castleton Tower, near Moab, pulsates at about the rate of a human heartbeat as it taps into the earth's natural vibrations.

Nathan Richman paragliding after delivering a seismometer to the summit of Castleton Tower in Castle Valley, Utah, last year. A nearby formation known as the Rectory is at right. Credit... Kat Vollinger

In 2013, a mutual friend brought Kat Vollinger and Nathan Richman together as rock climbing partners. Within a few years, they were married, and their shared love of climbing led them on adventures around the world. That's how, in March 2018, they found themselves scaling Castleton Tower, a nearly 400-foot sandstone spire near Moab, Utah, with a seismometer in tow.

Listen to Castleton Tower

A research team led by Jeff Moore, a geologist at the University of Utah, used a pair of seismometers to measure the movement of Castleton Tower, a rock formation in Utah. They sped up the low-frequency seismic data into audible sound.

Formed over tens of thousands of years, these structures have withstood earthquakes and heavy winds. But human-made sounds and vibrations - from helicopters, for instance, or highway traffic - may be challenging their endurance. As some of the most well-known and photographed arches in Arches National Park have collapsed over the past two decades, scientists, climbers, Native Americans and the National Park Service have been left to wonder: Is this normal? How much can a rock take?

The south face of Castleton Tower. It is one of many desert structures that Jeff Moore, a geologist at the University of Utah, has been monitoring with audio recordings. Credit... Jeff Moore

Kat Vollinger carrying instruments into an arch she and Mr. Richman measured in Canyonlands National Park in Utah. Credit... Nathan Richman

To assess how Castleton manages, Dr. Moore taught Ms. Vollinger and Mr. Richman to use a seismometer.

They placed one seismometer at the tower's base and then carried a second to the top, scaling its flat northern face. Placing a seismometer at each location allowed the researchers to distinguish between vibrations coming from the swaying of the tower and the ground around it.

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The climbers placed one of the seismometers directly on bedrock and underneath an insulated bucket, which protected it from temperature changes and direct exposure to wind. Credit... Nathan Richman

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Taking the Pulse of a Sandstone Tower in Utah

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Castleton Tower, near Moab, pulsates at about the rate of a human heartbeat as it taps into the earth's natural vibrations. In 2013, a mutual friend brought Kat Vollinger and Nathan Richman together as rock climbing partners. Within a few years, they were married, and their shared love of climbing led them on adventures around the world.

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Juan Cuartas

To be honest I took this class because it was required, but I have learned so much in this class, more than I ever thought I would. The lesson that really had an impact on me was the lesson on water conservation. I have never thought about Water conservation and this is the first time I've really seen the affects of my negligence. Every state is pretty much using a long straw to the colorado river.  If we don't make drastic changes now we may lose this river. In one of the clips from the Water conservation assignment, a homeowner went from having a lawn that's needing to be watered one day to a completely grassless lawn the very next day. Every neighborhood where I live has grass in the front and in the backyard. St George on the other hand has made great strides in their more developed areas. You can see full neighborhoods filled with lawn turf. It looks like grass it has a similar feel to grass but you never have to water it.

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http://eds.a.ebscohost.com.libprox1.slcc.edu:2048/eds/detail/detail?vid=1&sid=2a347f2c-eaee-4ffc-b17f-996edd7d3013%40sessionmgr4007&bdata=JnNpdGU9ZWRzLWxpdmU%3d#AN=100014744&db=buh

One of my favorite segments during this semester was learning about the amount of water that we each consume individually on a daily basis. I had no Idea that I was consuming so much water and the impact that such consumption could have on the environment. I had never really thought about my diet and how much water specific diets impact water intake. I will not be making the switch to being vegetarian any time soon but I am certainly more aware of the damage that that just several people can make if they are not aware of their water foot-print.

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Napali Coast Line Kauai, Hawaii

After learning more about the formations of the Hawaiian islands It made me appreciate the pictures I had taken on our helicopter tour in Kauai, Hawaii. The whole Nepali Coast Line is one of the biggest attractions in all of the Hawaiian islands. This coastline is viewable by air or by boat. It is very unique and because it is very hard to get there by foot, it makes it a special unique area that has little no to human interferance. I loved learning more about how these islands were formed due to plate movement as well at being part of the plate boundaries that have hot spots.

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Michelle Brandon

Following our discussion on water consumption and humanity's impact to our carbon footprint, I found myself looking more into how we are responsible for the greenhouse gases and global warming. I found this article to be fascinating as it specifically indicates how our increased greenhouse gas emissions will wreck havoc on our oceans and marine resources.

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Earth's Origin of Nitrogen revealed thanks to new geochemical tool.

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Earth's Origin of Nitrogen revealed thanks to new geochemical tool.

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Hailee Henson
" By analyzing volcanic gas samples from around the globe -- including gases from Iceland and Yellowstone National Park -- using a new method of analyzing "clumped" nitrogen isotopes. This method provided a unique way to identify molecules of nitrogen that come from air, which allowed the researchers to see the true gas compositions deep within Earth's mantle. This ultimately revealed evidence that nitrogen in the mantle has most likely been there since our planet initially formed." This article is interesting because it allows us new tools to discover more about our planet!

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Researchers at Woods Hole Oceanographic Institution (WHOI), the University of California Los Angeles (UCLA) and their colleagues used a new geochemical tool to shed light on the origin of nitrogen and other volatile elements on Earth, which may also prove useful as a way to monitor the activity of volcanoes. Their findings were published April 16, 2020, in the journal Nature.

Nitrogen is the most abundant gas in the atmosphere, and is the primary component of the air we breathe. Nitrogen is also found in rocks, including those tucked deep within the planet's interior. Until now, it was difficult to distinguish between nitrogen sources coming from air and those coming from inside the Earth's mantle when measuring gases from volcanoes.

"We found that air contamination was masking the pristine 'source signature' of many volcanic gas samples," says WHOI geochemist Peter Barry, a coauthor of the study.

Without that distinction, scientists weren't able to answer basic questions like: Is nitrogen left over from Earth's formation or was it delivered to the planet later on? How is nitrogen from the atmosphere related to nitrogen coming out of volcanoes?

Barry and lead author Jabrane Labidi of UCLA, now a researcher at Institut de Physique du Globe de Paris, worked in partnership with international geochemists to analyze volcanic gas samples from around the globe -- including gases from Iceland and Yellowstone National Park -- using a new method of analyzing "clumped" nitrogen isotopes. This method provided a unique way to identify molecules of nitrogen that come from air, which allowed the researchers to see the true gas compositions deep within Earth's mantle. This ultimately revealed evidence that nitrogen in the mantle has most likely been there since our planet initially formed.

"Once air contamination is accounted for, we gained new and valuable insights into the origin of nitrogen and the evolution of our planet," Barry says.

While this new method helps scientists understand the origins of volatile elements on Earth, it may also prove useful as a way of monitoring the activity of volcanoes. This is because the composition of gases bellowing from volcanic centers change prior to eruptions. It could be that the mix of mantle and air nitrogen could one day be used as a signal of eruptions.

This study was supported by the Deep Carbon Observatory and the Alfred P. Sloan Foundation. The research team also included colleagues David Bekaert and Mark Kurz from WHOI, scientists from several other U.S.-based universities, and from France, Canada, Italy, the United Kingdom and Iceland.

Journal Reference:

J. Labidi, P. H. Barry, D. V. Bekaert, M. W. Broadley, B. Marty, T. Giunta, O. Warr, B. Sherwood Lollar, T. P. Fischer, G. Avice, A. Caracausi, C. J. Ballentine, S. A. Halldórsson, A. Stefánsson, M. D. Kurz, I. E. Kohl, E. D. Young. Hydrothermal 15N15N abundances constrain the origins of mantle nitrogen. Nature, 2020; 580 (7803): 367 DOI: 10.1038/s41586-020-2173-4

Cite This Page:

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organic chemistry; aerospace; petroleum; air pollution; volcanoes; air quality; early climate; charles darwin; origin of life

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New geochemical tool reveals origin of Earth's nitrogen: Novel analysis method may also be useful for monitoring volcanic activity

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Researchers at Woods Hole Oceanographic Institution (WHOI), the University of California Los Angeles (UCLA) and their colleagues used a new geochemical tool to shed light on the origin of nitrogen and other volatile elements on Earth, which may also prove useful as a way to monitor the activity of volcanoes.

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Covid-19 and the change in fossil fuel consumption. 

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Covid-19 and the change in fossil fuel consumption. 

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Jon Sanchez

I was found this intriguing article about how covid-19 is not only causing massive damage to the economic status of many countries, but also its environment as well. This will change possibly in the next coming weeks, but it doesn't change the fact that for a short period of time humans were not using as much as the fossil fuels that they typically use.

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NASA Probes Environment, COVID-19 Impacts, Possible Links

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Scientists are using information from NASA's Earth-observing satellites, on-the-ground sensors and computer-based datasets to study the environmental, economic and societal impacts of the COVID-19 pandemic.

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Modern Climate Change Is the Only Worldwide Warming Event of the Past 2,000 Years

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Modern Climate Change Is the Only Worldwide Warming Event of the Past 2,000 Years

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Shannon Martin

I found it very interesting that this article stated that global climate change has only been occurring since the around the time of the industrial revolution. Before that, periods of temperature increases or decreases were localized to certain regions of the world, whereas now the temperatures are rising worldwide. This makes sense because of the growth of industries and other man made contributions of climate change.

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New research finds that previous periods of warming and cooling driven by natural causes were regional shifts in temperature rather than global events

smithsonianmag.com

A group of climate scientists has reached a surprising conclusion about Earth's past eras of naturally-driven, global warming and cooling-they weren't global after all.

The authors of new studies in and Nature Geoscience used evidence of ancient climates gathered around the world, from tree rings to coral reefs, to examine the pace and extent of well-known episodes of warming or cooling over the past 2,000 years. They report that events like the Little Ice Age and Mediaeval Warm Period, driven by natural variability, were actually more regional than global in scope.

In fact, the only time in the past 2,000 years that nearly all of the Earth has undergone significant warming or cooling is the present period of change that began in the 20th century, according to the research of Nathan Steiger, an atmospheric scientist at the Lamont-Doherty Earth Observatory of Columbia University, and colleagues. The rate of warming was also higher during the second half of the 20th century than during any similar period of the past 2,000 years, the studies found.

"It was surprising to us that the coherence of the climate, prior to the industrial revolution, was much more regional," Steiger says. "There were regional periods of cold or warmth, but it's only during the contemporary period where there's a global warm period that's very different from what we see in the past. On one hand it isn't all that surprising that the climate now is fundamentally different, but this provides a really nice long-term context where can clearly see that contrast."

Previous studies of past climates have identified well-known periods when the Earth warmed or cooled abruptly during the past 2,000 years. Standout eras include the Little Ice Age (1300s to 1800s), the Mediaeval Warm Period (800 to 1200), the Dark Ages Cold Period (400 to 800), and the Roman Warm Period, which occurred during the first few centuries A.D.

"I think that back in the past the assumption was that these must have been global events, and that if you have a record from a tree ring or an ice core somewhere on the planet you should see evidence of the Medieval Warm Period or you should see evidence of the Little Ice Age," says Scott St. George, who studies environmental variability at the University of Minnesota and wasn't involved in the research.

But the new studies suggest otherwise. For example, the coldest period of the Little Ice Age varied widely depending on the region of the planet. The coldest temperatures of the past 2,000 years occurred in the 15th century in the Pacific Ocean, the 17th century in northwestern Europe and southeastern North America, and elsewhere not until the mid-19th century.

Finding the warmest period of the past 2,000 years is far simpler. For 98 percent of the globe, the warmest temperatures in the last two millennia occurred in the late 20th century, the authors report.

Kevin Anchukaitis, a paleoclimatologist at the University of Arizona not involved in the research, says the idea that the Medieval period and Little Ice Age weren't eras of truly global change has been discussed in previous studies, and the authors' recent conclusions support that earlier work. "They were broad warm and cold periods, within which different regions of the globe had their coldest or warmest periods at different times. For the Little Ice Age, we know this is linked to volcanism," Anchukaitis says.

One of the studies also found that rates of warming during the second half of the 20th century were the fastest of the 2,000-year period, based on global average temperatures over timespans of two decades or more. "We looked at the warming rate, how fast it was warming or cooling over the globe over the last 2,000 years, and we found that the most drastic warming over the past 2,000 years occurred during the second half of the 20th century, which highlights the extraordinary character of current climate change," coauthor and paleolimnologist Raphael Neukom of the University of Bern said in a media briefing. Neukom also noted that the team's various past climate reconstructions largely agreed with the predictions of climate models on the scale of one to three decades, suggesting that those models' future climate forecasts may also be accurate over the next few decades.

"What struck me is how robust the earlier reconstructions are," says Kim Cobb, a climate scientist at the Georgia Institute of Technology unaffiliated with the research, agrees. "This vastly enriched dataset of new paleoclimate records, combined with state-of-the-art modeling, tends to confirm earlier efforts of climate scientists going back 20 years or more. ... So the idea that 20th century climate change is very unusual, and outside the rage of natural variability, is certainly being reinforced with an exclamation point now with these new efforts."

Both studies' global temperature reconstructions used multiple methodologies, created with the ever-growing repository of ancient climate data maintained in the Past Global Changes or PAGES 2k. Dozens of scientists from countries around the world have contributed nearly 700 records to the open-access database, adding details about ancient climate that were uncovered in glacial ice, ocean sediments, tree rings, corals and other sources. The resource allows scientists to recreate wide snapshots of global climate that would have been extremely difficult just a few short years ago.

"Each one of those records requires an enormous amount of work in the field, and then in the lab," St. George says. "When you think of ocean corals, a lot of those are recovered using an underwater drill by people in scuba suits. It's hard to find a 1,000-year-old tree that can reflect changes in temperature or find sediments in an undisturbed lake. So it's a real challenge sometimes, and there's a lot of effort that goes into each one of the data points that was used as the foundation for these climate maps."

Despite the fact that more data is available to paleoclimatologists than ever before, Anchukaitis believes that significantly more work needs to be done if scientists are to gather a truly global picture of past climate. "To make progress in understanding the climate of the [past 2,000 years], we should move beyond applying a smorgasbord of different statistical methods," he says via email. Instead, scientists need a renewed effort to gather paleoclimate records from places and times that are underrepresented in compilations like PAGES 2k.

"The proxy network is largely Northern Hemisphere tree-rings, tropical records (corals) decline rapidly by 1600, and there are relatively few Southern Hemisphere records outside of the Antarctic ice cores," Anchukaitis says. "So claims about global spatial patterns prior to about 1600, particularly for the tropics and southern hemisphere, must be viewed cautiously."

Neukom and colleagues' study also found that huge volcanic eruptions were a major driver of temperature fluctuations at timescales of two or three decades, while other natural factors, like solar output, didn't seem to have a significant influence. A third, related study by Stefan Brönnimann and colleagues focused exclusively on the role that five massive volcanic eruptions, including the 1815 Tambora episode, had on shaping climate at the end of the Little Ice Age. The eruptions created a cooling effect, weakened monsoons in Africa causing droughts, and shifted storm tracks over Europe that resulted in increased snowfall and glacier growth in the Alps.

This volcanically active time period, unusual in the past 2,000 years, coincides with the start of industrialization. The overlap makes teasing out which factors impacted climate at that time both difficult and extremely important.

"It does sort of mask the effect of industrial processes, where they are starting to omit more CO2, because they counteract each other," Steiger says. "So volcanoes could cool, and humans would warm by the release of greenhouse gasses. It's tricky to parse out what's what."

Taken together, the findings of these three studies help better our understanding of Earth's past climate history and highlight how contemporary climate change is unique over the past 2,000 years.

"They've shown that not only is the warming that we've experienced in the last few decades larger in magnitude than the kinds of changes we've seen due to natural factors in the past, [but] it's affecting almost the entire planet in the same way at the same time," St. George says. "That's really different than earlier prolonged climate changes due to natural factors which sometimes affected a large part of the planet but nothing close to 100 percent. The current warming that we're going through is almost everywhere, and that's what really makes it distinct from earlier climatic events due to natural causes."

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Modern Climate Change Is the Only Worldwide Warming Event of the Past 2,000 Years

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smithsonianmag.com A group of climate scientists has reached a surprising conclusion about Earth's past eras of naturally-driven, global warming and cooling-they weren't global after all. The authors of new studies in and Nature Geoscience used evidence of ancient climates gathered around the world, from tree rings to coral reefs, to examine the pace and extent of well-known episodes of warming or cooling over the past 2,000 years.

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Kendall Watkins

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Carla Shatz upends neuroscience

One of those scientists was Carla Shatz, professor of biology and neurobiology at Stanford University (shown), who shared the 2016 Kavli Prize for Neuroscience with Eve Marder of Brandeis University and Michael Merzenich of University of California, San Francisco. Shatz found that before birth, activity in the human retina sends signals that sculpt the neural circuitry in parts of the brain that make sense of what we see. The fact that neural activity alters brain wiring helps explain the brain's ability to adapt, and it shaped the modern concept of neuroplasticity.

Listen to Carla Shatz describe how research on babies' brains could help adults with brain damage and disease. Credit: Gabriela Hasbun

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Biggest Questions in Science: Carla Shatz

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One of those scientists was Carla Shatz, professor of biology and neurobiology at Stanford University (shown), who shared the 2016 Kavli Prize for Neuroscience with Eve Marder of Brandeis University and Michael Merzenich of University of California, San Francisco.

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Nitrogen Variations In the Mantle Might Have Survived Since Earth's Formation

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Nitrogen Variations In the Mantle Might Have Survived Since Earth's Formation

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Stephanie Daniel

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Earth's nitrogen-rich atmosphere contributes to the pleasant surface environment in which we live and breathe - but makes it very difficult to determine the nitrogen isotope composition of anything else. Pervasive atmospheric contamination of samples derived from Earth's mantle poses a formidable challenge to anyone investigating the origins and transport of volatile species, such as nitrogen and the noble gases, in the deep Earth. In a paper in Nature, Labidi et al. report that they have used a 'clumped isotope' method to identify uncontaminated mantle nitrogen in volcanic-gas effusions and gases trapped in volcanic-rock samples. The relative abundances of isotopes in uncontaminated nitrogen vary among samples from different locations. The authors argue that these differences originate from Earth's formation and have survived approximately 4.5 billion years of mixing associated with mantle convection.

There are two stable nitrogen isotopes, 14N and 15N, and their relative abundances are expressed as δ 15N values - the parts per thousand deviation of the 15N/ 14 N ratio from a standard value. The nitrogen isotopic compositions of mantle-derived samples can provide insight into a wide range of topics, from the mix of planetary building blocks that brought volatile species to Earth during its formation, to the transport of atmospheric nitrogen into the mantle through the sinking of tectonic plates over time.

Apart from the proportions of 14N and 15N in a sample, the way that isotopes are distributed between molecules also provides information. An isotopologue is a molecule that has a specific combination of isotopes of its constituent elements. For example, diatomic nitrogen molecules (N 2, which constitute about 78% of the atmosphere by volume) can incorporate either 14N or 15N, yielding three possible isotopologues: 14N 14N, 14N 15N and 15N 15N. Because the vast majority of nitrogen is 14N, the most common isotopologue is 14N 14N. Substitution of a single 15N for 14N is rare; a doubly substituted isotopologue ( 15N 15N) is rarer still. A random distribution of 14N and 15N between N 2 molecules produces a specific mixture of the three isotopologues. Any measured deviation from the expected proportion of 15N 15 N is described as a clumped-isotope anomaly.

Earth's atmospheric N 2 exhibits a well-resolved clumped-isotope anomaly, and Labidi et al. used this signature to identify atmospheric contamination of volcanic gases. The authors established that mantle N 2 has no clumped-isotope anomaly by analysing nitrogen released from unusually gas-rich samples of mid-ocean ridge basalt, confirming the expectation that magmatic gases have a random distribution of isotopes among N 2 isotopologues. With this information in hand, the authors examined nitrogen isotope compositions in hydrothermal gases sampled from Yellowstone National Park in the United States, Iceland and other volcanic localities. They identified the nitrogen isotope compositions of the mantle sampled at locations at which trends showing varying degrees of atmospheric contamination were evident.

In previous studies, of nitrogen in mantle-derived gases, systematic variations among measured nitrogen and noble-gas compositions were sought to identify atmospheric contamination, but contradictory signatures were sometimes observed - some metrics indicated that there was contamination, whereas others suggested there was none. Labidi and colleagues show that data that might have been interpreted as mantle compositions on the basis of relationships between nitrogen and noble gases are, in fact, affected by atmospheric N 2 contamination.

Their study also indicates that δ 15N variations are produced in atmospheric N 2 as it circulates through hydrothermal systems. However, the processes that generate such changes in the bulk proportions of 14N and 15N do not redistribute isotopes among isotopologues, so that the atmospheric clumped-isotope anomaly is preserved - which means that any contamination remains identifiable. There is no place for atmospheric N 2 to hide if one is looking through a clumped-isotope lens.

An important feature of the authors' analytical approach is that it is not necessary to measure pure, uncontaminated magmatic gas to estimate the mantle composition. Even if multiple atmospheric contaminants are present, evidence of mixing trends in the data can be used to identify the mantle δ 15N value of magmatic gas, which has no clumped-isotope anomaly. Labidi et al. report a mantle δ 15N value for the potentially deep-seated, Yellowstone mantle plume that is distinct from those determined for mid-ocean ridge basalts. With uncertainties regarding atmospheric contamination eliminated, nitrogen isotope variations in the mantle can be interpreted in the context of Earth's formation, differentiation into distinct layers, and the long-term coevolution of the deep Earth and surface owing to plate tectonics (Fig. 1).

To test whether nitrogen exchange between the surface and mantle over time explains their results, Labidi and co-workers developed a mathematical model of nitrogen evolution in the mantle. Intriguingly, the results suggest that there has been a net loss of nitrogen from the convective mantle over most of Earth's history, and little incorporation of surface nitrogen into the mantle. This contrasts with previously reported evidence of substantial incorporation of atmospheric xenon into the mantle,. Given the limited role of surface nitrogen in the mantle, the authors argue that the observed nitrogen isotope variations are a remnant from Earth's formation and early differentiation, when volatile species were delivered to the growing Earth as it separated into the core, mantle, crust and atmosphere.

Evidence that early-formed mantle heterogeneities survive in the modern mantle has come from studies of signatures formed by rapidly decaying radioactive isotopes that decayed within the first 100 million years of Earth's history,. It will be challenging to confirm that the nitrogen isotope variations identified by Labidi et al. arose early in Earth's evolution, given that neither of the element's two isotopes is produced by radioactive decay and that surface signatures might have a confounding role, however limited. Determination of δ 15N values at other plume localities, including regions thought to be influenced by the recycling of surface materials, would provide an interesting test of the authors' primordial hypothesis. The application of clumped-isotope analysis reported by Labidi et al. provides an exciting method for such future studies - we now have an improved tool with which to view the origins and evolution of volatile species in the mantle.

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Nitrogen variations in the mantle might have survived since Earth's formation

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A method for identifying atmospheric contamination of volcanic-gas samples reveals variations in the isotopic composition of nitrogen in the mantle, and provides a clearer view of the origins of this element in Earth's interior. An analysis of the nitrogen-isotope composition of volcanic gases.

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Emily Engh
This explains the Great Unconformity at the Grand Canyon.

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Achaias Haycock

With the increasing population, we only have a very limited amount of resources that can sustain the life and growth of our population. As quality of life grows, so does the amount of people who grow families, and the resources that are used. This article explains how we are already using 1.7 times the earth can sustain of resource use. These resources include, farm land, the water that is used, the elements such as deforestation and wood production.

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Robert B. Richardson, associate professor of sustainable development, Michigan State University. This article was originally published on The Conversation. Read the original article.

Purse seiner fishing in the Indian Ocean. Footprint estimates do not assess how sustainably resources such as fisheries are managed. Jiri Rezac, CC BY-SA Robert B. Richardson, Michigan State University

Experts widely agree that human activities are harming the global environment. Since the Industrial Revolution, the world economy has grown dramatically. Overall this is a success story, since rising incomes have lifted millions of people out of poverty. But it has been fueled by population growth and increasing consumption of natural resources.

Rising demand to meet the needs of more than 7 billion people has transformed land use and generated unprecedented levels of pollution, affecting biodiversity, forests, wetlands, water bodies, soils and air quality.

On Aug. 1, humans will have consumed more natural resources in 2018 than the Earth can regenerate this year, according to the California-based Global Footprint Network. This environmental nonprofit calculates the annual arrival of Earth Overshoot Day - the date when humanity's demands on nature exceed what the network's analysts estimate the Earth can regenerate over the entire year.

Aug. 1 is the earliest date since ecological overshoot began in the early 1970s. Global Footprint Network, CC BY-SA

As an ecological economist and scholar of sustainability, I am particularly interested in metrics and indicators that can help us understand human uses of Earth's ecosystems. Better measurements of the impacts of human activities can help identify ways to sustain both human well-being and natural resources.

Earth Overshoot Day is a compelling concept and has raised awareness of the growing impact of human activities on the planet. Unfortunately, the methodology used to calculate it and the ecological footprint on which it is based is conceptually flawed and practically unusable in any science or policy context. In my view, the ecological footprint ultimately does not measure overuse of natural resources - and it may very well underestimate it.

Rising demands, finite resources

The Global Footprint Network estimates when Earth Overshoot Day will arrive based on its National Footprint Accounts. These include extensive data sets that the organization uses to calculate two overarching indicators:

The ecological footprint, perhaps the most commonly used metric of the environmental impacts of human resource use. Each country's ecological footprint is an estimate of the biological resources required to meet its population's consumption demands and absorb its carbon emissions.

National biocapacity, which is an estimate of how well each country's ecosystems can produce the natural resources consumed by humans and absorb the waste and pollution that humans generate.

Both of these measures are expressed in global hectares. One hectare is equal to 10,000 square meters, or about 2.47 acres.

Going into overshoot

To estimate when Earth Overshoot Day will arrive, the Global Footprint Network calculates the number of days in a given year for which Earth has enough biocapacity to provide for humans' total ecological footprint. The rest of the year represents "global overshoot."

When the footprint of consumption worldwide exceeds biocapacity, the authors assert that humans are exceeding the regenerative capacity of Earth's ecosystems. This year, they estimate that humans are using natural resources 1.7 times faster than ecosystems can regenerate - or, put another way, consuming 1.7 Earths.

As an example, the ecological footprint for France is 4.7 global hectares per person, and global biocapacity is 1.7 hectares per person. Therefore, it would take (4.7/ 1.7 =) 2.8 Earths if everyone lived like the French.

France's Overshoot Day would be estimated as (365 x (1.7/ 4.7)) = 130, or the 130th day of the year, which is May 5 based on 2014 data. The United States reached overshoot even earlier, on March 15.

What to count?

However, there are some fundamental and misleading shortcomings in these calculations. In a 2013 paper, six authors from academia, The Nature Conservancy and the California-based Breakthrough Institute analyzed how the Ecological Footprint falls short. In their view, it primarily measures humans' carbon footprint but does not address other key impacts.

To calculate ecological footprints, the Global Footprint Network estimates the supply and demand of renewable biological resources across six land use types: forests, fishing grounds, croplands, grazing lands, developed lands and the area of forest required to offset human carbon emissions - that is, the carbon footprint. According to the network's own analysis, each of these land use types is nearly in balance or in surplus, except for the carbon footprint.

USDA NRCS South Dakota, CC BY-SA

The two key categories for producing food - cropland and grazing land - are defined in such a way that they can never be in deficit. And the analysis does not reflect environmental consequences of human use of these lands, such as soil erosion, nutrient runoff or overuse of water. It measures only land area.

For example, the ecological footprint for Indonesia is 1.61 global hectares per person, which is among the lowest 30 percent of all countries. But according to a 2014 study, Indonesia has the highest deforestation rate in the world.

Furthermore, the footprint calculation does not consider whether stocks of natural resources are decreasing or increasing as a result of human consumption. This question is critical for understanding ecological impacts.

These national ecological footprint calculations also conflate sustainability with self-sufficiency. They assume that every nation should produce all of the resources it consumes, even though it might be less expensive for countries to import some goods than to produce them at home.

As an example, the network lists Canada as an "ecological creditor" whose biocapacity exceeds its population's ecological footprint. However, Canada is among the top 10 oil-producing countries in the world, and exports much of that oil for foreign consumption. Most of it goes to the United States, an "ecological debtor" that consumes more resources than it produces.

Thinking purely in terms of generic "resources," everyone is better off when debtor countries can import resources from nations with supplies to spare. There are real and important environmental impacts associated with producing and consuming oil, but the network's calculations do not address them. Nor do they reflect the decline in natural capital from extracting a nonrenewable resource.

Measuring sustainability

The Global Footprint Network asserts that "You can't manage what you can't measure," but it may be impossible to create a single metric that can capture all human impacts on the environment. Earth Overshoot Day highlights unsustainable uses of natural resources, but we need scientifically robust ecological indicators to inform environmental policy, and a broader understanding of ecological risks.

Better measurements of sustainability should reflect changes in our supplies of natural capital, include estimates of uncertainty and incorporate multiple pathways to reducing carbon footprints. The best tool for measuring human impacts on the planet may be a dashboard of environmental indicators, not a footprint.

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Robert B. Richardson, associate professor of sustainable development, Michigan State University. This article was originally published on The Conversation. Read the original article. Purse seiner fishing in the Indian Ocean. Footprint estimates do not assess how sustainably resources such as fisheries are managed. Jiri Rezac, CC BY-SA Robert B.

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Jacob Roper

Paleontologist Kenneth Lacovara details the discovery of a 77 million year old dinosaur that aids in contemplating our place in time.

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Kenneth Lacovara: Hunting for dinosaurs showed me our place in the universe

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What happens when you discover a dinosaur? Paleontologist Kenneth Lacovara details his unearthing of Dreadnoughtus -- a 77-million-year-old sauropod that was as tall as a two-story house and as heavy as a jumbo jet -- and considers how amazingly improbable it is that a tiny mammal living in the cracks of the dinosaur world could evolve into a sentient being capable of understanding these magnificent creatures.

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Heat stress may affect more than 1.2 billion people annually by 2100

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Heat stress may affect more than 1.2 billion people annually by 2100

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Shawn Cogswell

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Heat stress from extreme heat and humidity will annually affect areas now home to 1.2 billion people by 2100, assuming current greenhouse gas emissions, according to a Rutgers study.

That's more than four times the number of people affected today, and more than 12 times the number who would have been affected without industrial era global warming.

The research is published in the journal Environmental Research Letters.

Rising global temperatures are increasing exposure to heat stress, which harms human health, agriculture, the economy and the environment. Most climate studies on projected heat stress have focused on heat extremes but not considered the role of humidity, another key driver.

"When we look at the risks of a warmer planet, we need to pay particular attention to combined extremes of heat and humidity, which are especially dangerous to human health," said senior author Robert E. Kopp, director of the Rutgers Institute of Earth, Ocean, and Atmospheric Sciences and a professor in the Department of Earth and Planetary Sciences in the School of Arts and Sciences at Rutgers University-New Brunswick.

"Every bit of global warming makes hot, humid days more frequent and intense. In New York City, for example, the hottest, most humid day in a typical year already occurs about 11 times more frequently than it would have in the 19th century," said lead author Dawei Li, a former Rutgers post-doctoral associate now at the University of Massachusetts.

Heat stress is caused by the body's inability to cool down properly through sweating. Body temperature can rise rapidly, and high temperatures may damage the brain and other vital organs. Heat stress ranges from milder conditions like heat rash and heat cramps to heat exhaustion, the most common type. Heat stroke, the most serious heat-related illness, can kill or cause permanent disability without emergency treatment, according to the U.S. Centers for Disease Control and Prevention.

The study looked at how combined extremes of heat and humidity increase on a warming Earth, using 40 climate simulations to get statistics on rare events. The study focused on a measure of heat stress that accounts for temperature, humidity and other environmental factors, including wind speed, sun angle and solar and infrared radiation.

Annual exposure to extreme heat and humidity in excess of safety guidelines is projected to affect areas currently home to about 500 million people if the planet warms by 1.5 degrees Celsius (2.7 degrees Fahrenheit) and nearly 800 million at 2 degrees Celsius (3.6 degrees Fahrenheit). The planet has already warmed by about 1.2 degrees (2.2 degrees Fahrenheit) above late 19th century levels.

An estimated 1.2 billion people would be affected with 3 degrees Celsius (5.4 degrees Fahrenheit) of warming, as expected by the end of this century under current global policies.

In New York City, extreme heat and humidity, comparable to the worst day in a typical year today, is projected to occur on four days in a typical year with global warming of 1.5 degrees Celsius (2.7 degrees Fahrenheit) and about eight days per year with warming of 2 degrees Celsius (3.6 degrees Fahrenheit). With 3 degrees Celsius (5.4 degrees Fahrenheit) of warming, extreme heat and humidity are projected to occur for about 24 days in a typical year.

The paper was co-authored by Jiacan Yuan, a former Rutgers assistant research professor in the Department of Earth and Planetary Sciences who is now at Fudan University in China.

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workplace health; mental health research; elder care; chronic illness; global warming; environmental issues; weather; climate

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Heat stress may affect more than 1.2 billion people annually by 2100: Rising global temperatures are increasing exposure to extreme heat and humidity

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Heat stress from extreme heat and humidity will annually affect areas now home to 1.2 billion people by 2100, assuming current greenhouse gas emissions, according to a new study. That's more than four times the number of people affected today, and more than 12 times the number who would have been affected without industrial era global warming.

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Switching from burning fossil fuels to biomass is not the solution some thought it would be. 

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Switching from burning fossil fuels to biomass is not the solution some thought it would be. 

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It was originally thought that if you cut a tree down to burn, another would grow in it's place and suck up the amount of carbon dioxide released in burning it, making it carbon neutral. However, scientists have found that time between the release of C02 from the burning and the payback from a mature tree is too long. We could do significant damage to the carbon cycle before new trees are able to grow.

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Of all the solutions to climate change, ones that involve trees make people the happiest. Earlier this year, when a Swiss study announced that planting 1.2 trillion trees might cancel out a decade's worth of carbon emissions, people swooned (at least on Twitter). And last month, when Ethiopian officials announced that twenty-three million of their citizens had planted three hundred and fifty million trees in a single day, the swooning intensified. Someone tweeted, "This should be like the ice bucket challenge thing."

So it may surprise you to learn that, at the moment, the main way in which the world employs trees to fight climate change is by cutting them down and burning them. Across much of Europe, countries and utilities are meeting their carbon-reduction targets by importing wood pellets from the southeastern United States and burning them in place of coal: giant ships keep up a steady flow of wood across the Atlantic. "Biomass makes up fifty per cent of the renewables mix in the E.U.," Rita Frost, a campaigner for the Dogwood Alliance, a nonprofit organization based in Asheville, North Carolina, told me. And the practice could be on the rise in the United States, where new renewable-energy targets proposed by some Democrats and Republicans in Congress, as well as by the E.P.A., treat "biomass"-fuels derived from plants-as "carbon-neutral," much to the pleasure of the forestry industry. "Big logging groups are up on Capitol Hill working hard," Alexandra Wisner, the associate director of the Rachel Carson Council, told me, when I spoke with her recently.

The story of how this happened begins with good intentions. As concern about climate change rose during the nineteen-nineties, back when solar power, for instance, cost ten times what it does now, people casting about for alternatives to fossil fuels looked to trees. Trees, of course, are carbon-when you burn them you release carbon dioxide into the atmosphere. But the logic went like this: if you cut down a tree, another will grow in its place. And, as that tree grows, it will suck up carbon from the atmosphere-so, in carbon terms, it should be a wash. In 2009, Middlebury College, where I teach, was lauded for replacing its oil-fired boilers with a small biomass plant; I remember how proud the students who first presented the idea to the board of trustees were.

William R. Moomaw, a climate and policy scientist who has published some of the most recent papers on the carbon cycle of forests, told me about the impact of biomass, saying, "back in those days, I thought it could be considered carbon neutral. But I hadn't done the math. I hadn't done the physics." Once scientists did that work, they fairly quickly figured out the problem. Burning wood to generate electricity expels a big puff of carbon into the atmosphere now. Eventually, if the forest regrows, that carbon will be sucked back up. But eventually will be too long-as the Intergovernmental Panel on Climate Change made clear last fall, we're going to break the back of the climate system in the next few decades. For all intents and purposes, in the short term, wood is just another fossil fuel, and in climate terms the short term is mostly what matters. As an M.I.T. study put it last year, while the regrowth of forests, if it happens, can eventually repay the carbon debt created by the burning of wood pellets, that payback time ranges from forty-four years to a hundred and four in forests in the eastern U.S., and, in the meantime, the carbon you've emitted can produce "potentially irreversible impacts that may arise before the long-run benefits are realized."

As the scientific research on this carbon debt emerged, in the past decade, at least a few of us in the environmental movement started voicing opposition to burning trees. The most effective leadership has come from the Southeast, where community activists have pointed out that logging rates are now the highest in the world, and that rural communities-often communities of color-are being disrupted by endless lines of logging trucks and by air pollution from plants where trees are turned into easy-to-ship pellets. Earlier this year, a proposal to build the largest pellet mill in the world, in Lucedale, Mississippi, drew opposition from a coalition that included the N.A.A.C.P. and which predicted that the plant would have a "disastrous effect on the people, wildlife, and climate."

But Mississippi environmental officials approved an air permit for the plant, which would employ ninety full-time workers, and so far European officials have also turned a deaf ear to the opposition: new E.U. regulations will keep treating the cutting down of trees as carbon neutral at least through 2030, meaning that utilities can burn wood in their old plants and receive massive subsidies for theoretically reducing their emissions. The Drax power plant, in the North of England, which burns more wood than any power plant on Earth, gets 2.2 million dollars a day in subsidies. But a new study, commissioned by the Southern Environmental Law Center and released on Monday, makes clear that, even under the most conservative estimates, Drax's burning of wood pellets that it imports from the American South will "increase carbon pollution in the atmosphere for more than forty years, well beyond the timeframe identified by the IPCC as critical for carbon reduction."

European subsidies treat power plants that burn wood as the equivalent of, say, solar panels, despite the fact that, under even the most generous scenarios, they emit at least ten times as much carbon, when factoring in the energy that it takes to make the panels. "They're looking for ways to shift their infrastructure without drastically overhauling it," Bob Musil, a veteran-environmentalist who now runs the Rachel Carson Council, said. "Ways that don't cause shifts in culture." It's remarkably similar to what happened in the United States with fracking: political leaders, including some in the Obama Administration, decided that the least-fuss way to replace coal would be with natural gas, only to learn that, as new science emerged, they had in fact replaced carbon emissions with leaking methane, which was making the climate crisis worse.

In this case, the greenwashing is particularly misleading, because burning trees defies the carbon math in another way, too: once they have been cut down, the trees won't be there to soak up the carbon. "The Southeast U.S. is falsely seen as a sustainable source of wood," Danna Smith, the executive director of the Dogwood Alliance, told me, because when the trees are cut down they can regrow-unlike, say, in the Amazon, where thin soils usually mean that when trees are cut down the land becomes pasture. She added, "But these forests are vital carbon sinks."

In fact, the newest research shows just what folly biomass burning really is. This summer, William Moomaw was the co-author of a paper that tracked carbon accumulation in trees. Planting all those trees in Ethiopia definitely helps pull carbon from the air, but not as much as letting existing trees keep growing would. Unlike human beings, who gain most of their height in their early years, Moomaw explained to me, "trees grow more rapidly in their middle period, and that extends far longer than most people realize." A stand of white pines, for instance, will take up twenty-two tons of carbon by its fiftieth year, which is about when it would get cut down to make pellets. "But, if you let it grow another fifty years, it adds twenty-five tons," he said. "And in the next fifty years it adds 28.5 tons. It would be a mistake to cut them down when they're forty and make plywood. It's really foolish to cut them down when they're forty and burn them, especially now that we've got cheap solar." He calls letting trees stand and accumulate carbon "proforestation"-as opposed to reforestation.

"You can get to some pretty big numbers this way," Moomaw added. "The Woods Hole Research Center found that, if we let secondary forests grow around the world, they would sequester 2.8 billion tons of carbon a year, which is about sixty per cent of the gap between what humans produce annually and what natural systems currently soak up. Instead, we're increasingly cutting them down to burn for fuel." Earlier this year, Moomaw helped draft a letter to the European Parliament which made these points, and it was signed by nearly eight hundred scientists, mostly from Europe and North America. So far, the scientists have received no reply; perhaps they should have also sent an ice bucket.

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Don't Burn Trees to Fight Climate Change-Let Them Grow

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Of all the solutions to climate change, ones that involve trees make people the happiest. Earlier this year, when a Swiss study announced that planting 1.2 trillion trees might cancel out a decade's worth of carbon emissions, people swooned (at least on Twitter).

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speaking about tracking the rise in ocean levels into the year 2030.

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Climate Change: Vital Signs of the Planet

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Earth's climate is changing, and the study of oceans is vital to understanding the effects of those changes on our future. For the first time, U.S. and European agencies are preparing to launch a 10-year satellite mission to continue to study the clearest sign of global warming - rising sea levels. The Sentinel-6/Jason-CS mission (short for Jason-Continuity of Service), will be the longest-running mission dedicated to answering the question: How much will Earth's oceans rise by 2030?

By 2030, Sentinel-6/Jason-CS will add to nearly 40 years of sea level records, providing us with the clearest, most sensitive measure of how humans are changing the planet and its climate.

The mission consists of two identical satellites, Sentinel-6A and Sentinel-6B, launching five years apart. The Sentinel-6A spacecraft was on display for the media on Nov. 15 for a last look in its clean room in Germany's IABG space test center. The satellite is being prepared for a scheduled launch in November 2020 from Vandenberg Air Force Base in California on a SpaceX Falcon 9 rocket.

Sentinel-6/Jason-CS follows in the footsteps of four other joint U.S.-European satellite missions - TOPEX/Poseidon and Jason-1, Ocean Surface Topography/Jason-2, and Jason-3 - that have measured sea level rise over the past three decades. The data gathered by those missions have shown that Earth's oceans are rising by an average of 0.1 inches (3 millimeters) per year.

Sentinel-6/Jason-CS will continue that work, studying not just sea level change but also changes in ocean circulation, climate variability such as El Niño and La Niña, and weather patterns, including hurricanes and storms.

"Global sea level rise is, in a way, the most complete measure of how humans are changing the climate," said Josh Willis, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "If you think about it, global sea level rise means that 70 percent of Earth's surface is getting taller - 70 percent of the planet is changing its shape and growing. So it's the whole planet changing. That's what we're really measuring."

Decades of space- and ground-based observations have documented Earth's surface temperature rising at a rapidly accelerating rate. The oceans help to stabilize our climate by absorbing over 90 percent of the heat trapped on the planet by excess greenhouse gases, like carbon dioxide, that have been emitted into the atmosphere since the start of the Industrial Revolution.

As the oceans warm, they expand, increasing the volume of water; the trapped heat also melts ice sheets and glaciers, contributing further to sea level rise. The rate at which it is rising has accelerated over the past 25 years and is expected to continue accelerating in years to come.

Sentinel-6/Jason-CS will measure down to the millimeter how much global sea level rises during the 2020s and how fast that rise accelerates. As the rate increases, humans will need to adapt to the effects of rising seas - including flooding, coastal erosion, hazards from storms and negative impacts to marine life.

Along with measuring sea level rise, the mission will provide datasets that can help with weather predictions, assessing temperature changes in the atmosphere and collecting high-resolution vertical profiles of temperature and humidity.

As with its Jason-series predecessors, Sentinel-6/Jason-CS will gather global ocean data every 10 days, providing insights into large ocean features like El Niño events. However, unlike previous Jason-series missions, its higher-resolution instruments will also be able to provide data on smaller ocean features - including complex currents - that will benefit navigation and fishing communities.

"Global sea level rise is one of the most expensive and disruptive impacts of climate change that there is," said Willis. "In our lifetimes, we're not going to see global sea level fall by a meaningful amount. We're literally charting how much sea level rise we're going have to deal with for the next several generations."

Sentinel-6/Jason-CS is being jointly developed by the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellite (EUMETSAT), NASA and the National Oceanic and Atmospheric Administration (NOAA) with funding support from the European Commission and support from France's National Centre for Space Studies (CNES). NASA's contributions to the Sentinel-6 mission are science instrument payloads for the two Sentinel-6 satellites, launch services for those satellites, ground systems supporting the science instruments operations and support for the international Ocean Surface Topography Science Team.

To learn more about NASA missions studying climate change, visit:

To learn more about NASA's study of sea level rise, visit:
https://sealevel.nasa.gov
View the latest sea level data in Earth Now:
https://go.nasa.gov/341j5aV
News Media Contact

Arielle Samuelson
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307
arielle.a.samuelson@jpl.nasa.gov

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national aeronautics and space administration

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By Arielle Samuelson,
NASA's Jet Propulsion Laboratory

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New Earth Mission Will Track Rising Oceans Into 2030 - Climate Change: Vital Signs of the Planet

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Earth's climate is changing, and the study of oceans is vital to understanding the effects of those changes on our future. For the first time, U.S. and European agencies are preparing to launch a 10-year satellite mission to continue to study the clearest sign of global warming - rising sea levels.

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This TED Talk is about a easy way we can all help climate change, and how we should not be degrading our soil.

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Get a daily email featuring the latest talk, plus a quick mix of trending content.

By subscribing, you understand and agree that we will store, process and manage your personal information according to our Privacy Policy

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Asmeret Asefaw Berhe: A climate change solution that's right under our feet

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There's two times more carbon in the earth's soil than in all of its vegetation and the atmosphere -- combined. Biogeochemist Asmeret Asefaw Berhe dives into the science of soil and shares how we could use its awesome carbon-trapping power to offset climate change.

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This article shows you in a visual way where and how extensive the earth is warming. Sometimes just reading something doesn't convey the seriousness of the problem like a visual representation does

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Climate Change: Vital Signs of the Planet

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Home - Climate Change: Vital Signs of the Planet

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Vital Signs of the Planet: Global Climate Change and Global Warming. Current news and data streams about global warming and climate change from NASA.

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This article discusses the properties of some corals and their resistance to the changing environment, as well as their ability to rehabilitate other corals. Giving a bit of hope to previous predictions.

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Anne Cohen dropped into the ocean off the coast of the Phoenix Islands expecting to find desolation. It was 2018, and a powerful El Niño weather system two years earlier had warmed the waters around this mid-Pacific atoll by nearly 3 °C. Coral reefs simmered in the heat.

Such feverish temperatures cause the tiny animals that make up a reef to expel the colourful, symbiotic algae that nourish them. They bleach, starve and die. On her expedition to the islands, part of the nation of Kiribati, Cohen found greyish reefs in which almost 70% of corals had expired.

But she also found reason for hope.

"We'd come across these areas, I'm talking about several square kilometres, with super-high coral cover and super-high coral diversity," recalls Cohen, a marine scientist at the Woods Hole Oceanographic Institution in Massachusetts. Healthy taupe coral branches sprouted from a field of blonde and rose plates, while schools of gold-and-magenta anthias fish flitted to and fro.

Such places give ocean ecologists hope that even as the climate warms, corals still have a fighting chance. When these scientists hear that 70-90% of reefs could be gone by mid-century, they focus on the 30% that might live. And they're taking action to save those reefs for the future. Around the world, hundreds of millions of people depend on reefs for food, tourism income and protection from ocean storms.

Researchers and conservationists are testing many strategies to help corals. Some approaches - such as breeding or genetically manipulating corals to tolerate climate change, or sprinkling reefs with beneficial microbes - have yet to prove themselves outside of the laboratory.

But scientists are already trying out other ideas in the wild: growing and replanting corals in damaged reefs, for instance, and helping them to breed. And there's another tactic getting attention - finding the reefs that have the best natural chances of survival and helping them to stay alive. There are downsides to both of these approaches, however: breeding is impractical at large scales, and some researchers worry that focusing only on naturally resilient reefs will constrain conservation to a few niche locations.

Conservationists say that it will take a variety of strategies to save coral reefs, but the time is now. "The next decade is really our window," says Lizzie McLeod, who works in reef management at the Nature Conservancy in Alexandria, Virginia.

Half the globe's reefs are already gone. Carbon pollution heats up the ocean and turns it more acidic, making it difficult for the delicate creatures to build their calcium carbonate skeletons. Human activities such as fishing, dredging, pollution and development have also caused serious harm.

The efforts to save particular reefs are offering some hope, researchers say, but these solutions are only a stop-gap. "Unless we curb carbon emissions, none of this is going to make any difference whatsoever," says Iliana Baums, a molecular ecologist at Pennsylvania State University (Penn State) in University Park.

Helping hands

In the Caribbean Sea, a one-two punch of climate change and disease has hit reefs hard. "The Florida reef tract has been going downhill for the last 40 years or so," says Erinn Muller, science director of the Elizabeth Moore International Center for Coral Reef Research & Restoration at the Mote Marine Laboratory & Aquarium in Sarasota, Florida. "We really haven't seen any natural recovery."

So conservationists from Mote and other organizations are taking matters into their own hands. Over the past several years, the Mote laboratory's reef-restoration teams have planted almost 70,000 pieces of coral from five main species off the Florida Keys. The goal of this project, and others like it around the world, is not to replant reefs entirely, but to provide enough new corals to allow them to reproduce themselves.

Mote's coral nannies start with artificial, ocean-based nurseries. They create tree-like structures by hanging fishing line from buoys and attaching plastic branches. Then they dangle individual corals from those branches.

Once the danglers reach about the size of a basketball, divers carve out softball-sized chunks. Then Muller and her colleagues test the corals, ensuring that some in each batch have the genes to resist dangers such as diseases, heat or acidification, before the restoration crew plants them on the sea floor.

The reef begins to recover within a year, says Muller, and more fish and invertebrates move in. Eventually, the planted chunks will fuse into larger corals. From their experiences with past plantings, the researchers know that the corals will be big enough to spawn within a couple of years.

This works for fast-growing, branching corals. But some mound and boulder corals expand slowly - just a couple of millimetres per year. Mote researchers speed that up by cutting the corals into tiny pieces and affixing them to small, round tiles with stems, like a ceramic flower. In the lab's on-shore tanks, the fingernail-sized fragments grow up to 50 times faster than the full-sized corals, reaching 3 centimetres across in a few months.

To replant them, the restoration team finds a large coral head from which the animals have disappeared but left their limestone skeletons. Divers drill about 20 holes in that dead coral, and poke in the stems of the coral-tile flowers. Eventually, the pieces grow together, 're-skinning' the dead coral and restoring it to spawning in two to three years.

"It's a way to jump-start the reef," says Emily Hall, a chemical ecologist at Mote. The lab places thousands of these coral-flowers every year, says Muller, and typically achieves more than 80% survival.

The microfragmentation approach is promising, says Dirk Petersen, executive director of the coral conservation non-profit organization SECORE International in Bremen, Germany. But he has doubts about re-skinning. The old coral head might have new residents that could harm or compete with the coral-flowers, he says, and organisms that killed the original inhabitants might still be present.
Romancing the reef
Mote, SECORE and others are also helping corals to reproduce. By assisting breeding, reef managers can make not just more corals, but more diverse populations. Some larvae will be heat-tolerant, some resistant to acidified waters. Nature will select those that match a given reef's conditions.

It was in pursuit of this diversity that Baums went to the Caribbean island of Curaçao in August. She and her colleagues from SECORE teamed up with local conservationists to perform in vitro fertilization for elkhorn coral ( Acropora palmata).

The affair began a couple of hours after sunset, under a full moon. Corals spewed their gametes into the water. Sperm and eggs were so thick, they formed a slick on the surface. Baums and the other divers secured nets over the colonies to collect the gametes.

Because gametes are viable only for a few hours, the team had to race to pair up compatible eggs and sperm. "We have used a bench on the beach as an improvized laboratory," says Petersen. The low-tech lab can boost fertilization rates to 90% or higher.

Then, SECORE placed the embryos in the nursery, a floating pool in the sea that is protected from predators. A few days later, larvae settled on 3D-printed, starfish-shaped structures. When the corals reach about fingernail size, divers will wedge these substrates into the crevices of needy reefs. Petersen says this approach has also been tested in reefs off Mexico, Florida, the Bahamas, the Dominican Republic, Bonaire, Australia, Palau and Guam.

Although these restoration measures are beneficial in deeply damaged reefs, they are difficult and costly to deploy at scale. Consider Australia's Great Barrier Reef, which is close to the size of Italy. Heatwaves in 2016 and 2017 bleached half the corals. Although some restoration is happening, surviving corals in larger areas have to help themselves, says Terry Hughes, director of the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University in Townsville. "Billions of tougher corals survived, and they're breeding."

Come hell or hot water

Fortunately, the Great Barrier Reef's neighbourhood is better off than the Caribbean's. "The Indo-Pacific is still in great shape," says Emily Darling, a conservation scientist at the Wildlife Conservation Society in Toronto, Canada.

In August, a large team led by Darling published an analysis of 2,584 Indo-Pacific reefs. The good news is that 86% of those reefs were dominated by large species such as branching, plating and boulder corals, the types that create fish habitats and shield shorelines from storms.

The bad news is that these species are also the most sensitive to heat.

Darling and her colleagues identified a group of almost 450 reefs that had been affected very little by recent warming events and had retained more than 10% coral cover - the minimum at which the reef can build more skeleton than it's likely to lose (but still well below the area's coral cover in decades past). "Right now, I would really target those to save," says Darling.

Cohen, too, is on a quest to find resilient reefs and make sure they are protected in her Super Reefs project (see 'The reef half full').

Her team has found three ways in which reefs beat the heat. Some corals live in naturally warm environments and are genetically adapted to deal with scorching temperatures. For example, reefs off Palau's Rock Islands withstood major heatwaves in 1998 and 2010. In the nearby barrier reef, where the water is typically cooler, coverage dropped to 5-6%. Other reefs are simply lucky in location. Some benefit from cold currents that protect them from hot spells. Others are served by currents that provide a constant plankton buffet. Even if they bleach, these corals remain well-fed and survive.

"So far," says Cohen, "most of the super reefs we've found have been by accident." To find more, she's using hydrodynamic modelling of currents to identify likely spots, and developing underwater robots that can identify areas with living corals and hover over them to gather data. "I'm convinced there are super reefs in most places," she says.

The next step will be to protect them. For example, Cohen is working with the Nature Conservancy and the government of the Marshall Islands to identify resilient reefs in the nearby waters, and to ensure that the nation includes some of these corals in any new marine protected areas.

Another researcher on the hunt for resilient reefs is Ove Hoegh-Guldberg, a marine scientist at the University of Queensland in Brisbane, Australia. He borrowed an algorithm from the world of finance to find them.

Investors want a diverse portfolio that balances risk and reward. Hoegh-Guldberg joined forces with other coral specialists and economists to apply the same logic to the world's reefs. For example, being in the predicted path of cyclones might put a reef at high risk, but having good tolerance for climate change, or being well-connected to other reefs that could need re-seeding, would give it a high benefit profile.

Considering 30 such factors, the group identified 50 ocean regions scattered throughout the tropics, each about 500 square kilometres, as conservation priorities. If the rest of the world's reefs are wiped out, these reefs might be able to kick-start repopulation, assuming the climate stabilizes, Heogh-Guldberg says.

Some find the idea of singling out survivors troubling. "I hope it doesn't come to the point that we have to pick and choose one reef over another," says Hall. "I think all reefs are important."

Mónica Medina, a coral-reef biologist at Penn State, called the idea of relying on naturally robust corals "dangerous" at an October meeting of science writers held at her university. Corals that are resilient in one habitat might not thrive elsewhere, she pointed out, and the idea can lull people into thinking that reefs don't need other assistance.

Both Heough-Guldberg and Cohen stress that they don't intend for only these special reefs to receive conservation attention. In his '50 Reefs' project, Heogh-Guldberg is simply hedging his bets by identifying some promising targets. "You have a good chance of winning, no matter what."

Social science

In one of his 50 regions, off Madagascar, the wildlife charity WWF is helping protect a beautiful reef. Broad table corals rise in layers, and sea turtles prowl the clear waters. Although there are some signs of bleaching from past stress, the reef has mostly recovered, says Gabby Ahmadia, a marine conservation scientist with the WWF in Washington DC. But there aren't quite as many fish as there ought to be.

The way to solve that fish deficit is as much about local people as it is about marine ecology, she says. Conservation groups have helped locals to set up boutique tourism. The Nosy Hara marine national park pays community rangers to keep an eye on the corals. Fishers across Madagascar teach each other protective practices.

Conservationists are applying similar strategies in several places, customized to the people and the environment. It's societal action, not biology, that will ultimately save reefs, Hughes says. "They'll die again if we don't first fix water pollution, overfishing and ever-rising emissions."

Nonetheless, conservationists cling to hope for the future - albeit tempered with realism. "I think we can resolve this crisis," says Petersen. "I'm also sure that reefs will look different than they do now." Coral ecologists might have to sacrifice species diversity to rescue the whole ecosystem. Petersen compares future reefs to modern, managed forests, which host a narrower mix of trees than untouched forests, but still provide habitats for wildlife and help to cleanse water and air.

Another reason for hope is that reefs have made it through other challenges. Reef-building corals are part of a lineage that is more than 400 million years old. They've endured global water temperatures that have swung between 10 and 32 °C, and carbon dioxide levels up to quadruple those of today. But they've never before had to endure such rapid warming.

The current pace of climate change could stretch corals beyond their adaptive limits. Even if nations succeeded in limiting global warming to 1.5 °C above 1990 levels, the target of the 2018 Paris agreement, 70-90% of reefs would be lost, according to the Intergovernmental Panel on Climate Change. And that target is looking more and more unrealistic. If the climate warms by 2 °C, the panel projects losses of greater than 99%.

Still, researchers are confident that with human assistance, and a global drop in emissions, reefs can rise again. "Corals 'know' how to recover, they know how to regenerate themselves," says Hoegh-Guldberg. "Corals are almost made for this."

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These corals could survive climate change - and help save the world's reefs

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Ocean warming threatens to wipe out corals, but scientists are trying to protect naturally resilient reefs and are nursing some others back to health. Ocean warming threatens to wipe out corals, but scientists are trying to protect naturally resilient reefs and are nursing some others back to health.

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Stacie Smith - Panama Canal Construction

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Stacie Smith - Panama Canal Construction

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I recently had the opportunity to go through the new locks at the Panama Canal. During this time I learned about the history of the canal and was able to see how they cut through the land to create the canal and lake. This is a film that is an introduction to the construction of the Panama Canal

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Panama Canal Construction in 1912 | American Vintage Documentary

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This is an article with a short interview of scientist, Philip Fearnside, for Brazil’s National Institute of Amazonian Research in Manaus, with insight as to who is to blame.

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Development, most of it illegal, destroyed more than 9700 square kilometers of Brazilian Amazon rainforest in the year ending in July, according to a government estimate released on Monday-an increase of 30% from the previous year and the highest rate of deforestation since 2007-08.

The number is based on analysis of high-resolution Landsat satellite images by the Program for Monitoring Deforestation of the Amazon by Satellite (PRODES), run by Brazil's National Institute for Space Research. The estimate confirms indications of increased forest loss reported earlier this year by a different system, the Real-Time Deforestation Detection System (DETER), which uses lower resolution satellite images for real-time monitoring of illegal activities in the forest.

Many scientists and environmentalists blame the deforestation spike on President Jair Bolsonaro's aggressive policies to support mining and ranching and to dismantle environmental protections. But Minister of the Environment Ricardo Salles has said the increased deforestation continues a trend that began in 2012, before Bolsonaro was elected. Science asked Philip Fearnside, a scientist at Brazil's National Institute of Amazonian Research in Manaus, who's right. Thisinterviewhas been edited for clarity and brevity.
Q: The Brazilian government argues we're looking at the continuation of a rising trend that began in 2012-not a deviation that can be blamed on the current administration. How do you see this?
A: The deforestation surge in 2019 can definitely be blamed on the Bolsonaro administration, despite the fact that twice since 2012 [in 2013 and 2016], the deforestation rate approached this year's growth percentage. It should be remembered that the PRODES data only cover the year through July 31. The deforestation rate in the following months exploded to levels far above those for the same months in the previous year [according to DETER data], reaching 222% above the 2018 value in August. This part of the Bolsonaro effect will only be reflected in the PRODES numbers that will be released a year from now.
Q: What particular actions and/or words from the Bolsonaro administration have contributed most to this rise in deforestation, in your view?
A: The change results both from the constant antienvironment rhetoric and from concrete actions in dismantling the country's environmental agencies and effectively halting fines for illegal clearing. The rhetoric and institutional setbacks are documented in detail in a recent paper that I co-authored. The discourse of the president and his minister of environment sends a clear message that there will be no consequences for violating environmental laws. When the ministers of environment and agriculture visited an illegal soy plantation in an indigenous area in Mato Grosso, they posed for photographs with the machinery and praised the operation. Those at the deforestation frontier do not follow the publication of decrees and laws in the government's official gazette or read the details of legal changes reported in major newspapers. Instead, their information comes from social media that rapidly spreads the news of each tirade by the president and his ministers against environmental agencies and NGOs [nongovernmental organizations].
Q: Why was deforestation on the rise since 2012? What was happening before Bolsonaro came along?
A: Deforestation has risen since 2012 due the continual increase in forces driving forest loss, such as more roads giving access to the forest, an increasing population, and more investment. The indirect effect of soy expansion has undoubtedly played an important role, with soy planters purchasing many cattle ranches in the state of Mato Grosso-not only in former Amazon forest, but also in the Cerrado savanna area. These ranchers use the money from the land sales to buy much cheaper land in the Amazon forest further north, especially in the state of Pará, where they clear forest on a large scale to establish new ranches. Pará has been the biggest contributor to deforestation since 2006, when it surpassed Mato Grosso.
Q: What are your perspectives for 2020?
A: They're grim. The PRODES data for next year will include deforestation that has occurred since August, which now totals at least 3929 square kilometers, based on the DETER monitoring system. Nothing has changed in the presidential administration's discourse, and the dismantling of the country's environmental institutions continues. Various planned roads, dams, and other projects in Amazonia will lead to more deforestation.

doi:10.1126/science.aba3238

Herton Escobar is a science and environment journalist in São Paulo, Brazil.

More from News

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Brazil's deforestation is exploding-and 2020 will be worse

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Development, most of it illegal, destroyed more than 9700 square kilometers of Brazilian Amazon rainforest in the year ending in July, according to a government estimate released on Monday-an increase of 30% from the previous year and the highest rate of deforestation since 2007-08.

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This article defines the effects and history of Greenhouse Gases on the planet and how Carbon Dioxide has increased in the last 800,000 years.

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Landsat 8 acquired this image of Mauna Loa on December 20, 2014. The CO2 observatory is located just north of the summit caldera. Credit: NASA Earth Observatory/Landsat 8. Learn more about the image here.

If you follow science news, this will probably sound familiar.

In May 2019, when atmospheric carbon dioxide reached its yearly peak, it set a record. The May average concentration of the greenhouse gas was 414.7 parts per million (ppm), as observed at NOAA's Mauna Loa Atmospheric Baseline Observatory in Hawaii. That was the highest seasonal peak in 61 years, and the seventh consecutive year with a steep increase, according to NOAA and the Scripps Institution of Oceanography.

The Mauna Loa Observatory has been measuring carbon dioxide since 1958. The remote location (high on a volcano) and scarce vegetation make it a good place to monitor carbon dioxide because it does not have much interference from local sources of the gas. (There are occasional volcanic emissions, but scientists can easily monitor and filter them out.) Mauna Loa is part of a globally distributed network of air sampling sites that measure how much carbon dioxide is in the atmosphere.

Global concentrations of atmospheric carbon dioxide spike every April or May, but in 2019 the spike was bigger than usual. The dashed red line represents the monthly mean values; the black line shows the same data after the seasonal effects have been averaged out. Credit: NOAA. Read more about the image here.

The broad consensus among climate scientists is that increasing concentrations of carbon dioxide in the atmosphere are causing temperatures to warm, sea levels to rise, oceans to grow more acidic, and rainstorms, droughts, floods and fires to become more severe. Here are six less widely known but interesting things to know about carbon dioxide.

The rate of increase is accelerating.

For decades, carbon dioxide concentrations have been increasing every year. In the 1960s, Mauna Loa saw annual increases around 0.8 ppm per year. By the 1980s and 1990s, the growth rate was up to 1.5 ppm year. Now it is above 2 ppm per year. There is "abundant and conclusive evidence" that the acceleration is caused by increased emissions, according to Pieter Tans, senior scientist with NOAA's Global Monitoring Division.

Credit: NOAA/Scripps Institute of Oceanography. Read more about the chart here.

Scientists have detailed records of atmospheric carbon dioxide that go back 800,000 years.

To understand carbon dioxide variations prior to 1958, scientists rely on ice cores. Researchers have drilled deep into icepack in Antarctica and Greenland and taken samples of ice that are thousands of years old. That old ice contains trapped air bubbles that make it possible for scientists to reconstruct past carbon dioxide levels. The video below, produced by NOAA, illustrates this data set in beautiful detail. Notice how the variations and seasonal "noise" in the observations at short time scales fade away as you look at longer time scales.

CO2 is not evenly distributed.

Satellite observations show carbon dioxide in the air can be somewhat patchy, with high concentrations in some places and lower concentrations in others. For instance, the map below shows carbon dioxide levels for May 2013 in the mid-troposphere, the part of the atmosphere where most weather occurs. At the time there was more carbon dioxide in the northern hemisphere because crops, grasses, and trees hadn't greened up yet and absorbed some of the gas. The transport and distribution of CO2 throughout the atmosphere is controlled by the jet stream, large weather systems, and other large-scale atmospheric circulations. This patchiness has raised interesting questions about how carbon dioxide is transported from one part of the atmosphere to another-both horizontally and vertically.

The first space-based instrument to independently measure atmospheric carbon dioxide day and night, and under both clear and cloudy conditions over the entire globe, was the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite. Read more about this image here. The OCO-2 satellite, launched in 2014, also makes global measurements of carbon dioxide, and it does so at even lower in the atmosphere than AIRS.

Despite the patchiness, there is still lots of mixing.

In this animation from NASA's Scientific Visualization Studio, big plumes of carbon dioxide stream from cities in North America, Asia, and Europe. They also rise from areas with active crop fires or wildfires. Yet these plumes quickly get mixed as they rise and encounter high-altitude winds. In the visualization, reds and yellows show regions of higher than average CO2, while blues show regions lower than average. The pulsing of the data is caused by the day/night cycle of plant photosynthesis at the ground. This view highlights carbon dioxide emissions from crop fires in South America and Africa. The carbon dioxide can be transported over long distances, but notice how mountains can block the flow of the gas.

Carbon dioxide peaks during the Northern Hemisphere spring.

You'll notice that there is a distinct sawtooth pattern in charts that show how carbon dioxide is changing over time. There are peaks and dips in carbon dioxide caused by seasonal changes in vegetation. Plants, trees, and crops absorb carbon dioxide, so seasons with more vegetation have lower levels of the gas. Carbon dioxide concentrations typically peak in April and May because decomposing leaves in forests in the Northern Hemisphere (particularly Canada and Russia) have been adding carbon dioxide to the air all winter, while new leaves have not yet sprouted and absorbed much of the gas. In the chart and maps below, the ebb and flow of the carbon cycle is visible by comparing the monthly changes in carbon dioxide with the globe's net primary productivity, a measure of how much carbon dioxide vegetation consume during photosynthesis minus the amount they release during respiration. Notice that carbon dioxide dips in Northern Hemisphere summer.

Credit: NASA Earth Observatory. Read more about this image here.

It isn't just about what is happening in the atmosphere.

Most of Earth's carbon-about 65,500 billion metric tons-is stored in rocks. The rest resides in the ocean, atmosphere, plants, soil, and fossil fuels. Carbon flows between each reservoir in the carbon cycle, which has slow and fast components. Any change in the cycle that shifts carbon out of one reservoir puts more carbon into other reservoirs. Any changes that put more carbon gases into the atmosphere result in warmer air temperatures. That's why burning fossil fuels or wildfires are not the only factors determining what happens with atmospheric carbon dioxide. Things like the activity of phytoplankton, the health of the world's forests, and the ways we change the landscapes through farming or building can play critical roles as well. Read more about the carbon cycle here.

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If you follow science news, this will probably sound familiar. In May 2019, when atmospheric carbon dioxide reached its yearly peak, it set a record. The May average concentration of the greenhouse gas was 414.7 parts per million (ppm), as observed at NOAA's Mauna Loa Atmospheric Baseline Observatory in Hawaii.

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This article gives an analyst of the division of earthly preservation as well as economic interest.

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Climate Change - We are the PROBLEM & the SOLUTION (Animated Infographic)

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Climate Change - We are the PROBLEM & the SOLUTION (Animated Infographic)

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This infographic talks about climate change patterns throughout the Earth's history, and the affects that humans have had on the climate.

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Climate Change - We are the PROBLEM & the SOLUTION (Animated Infographic)

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This article gives us some more evidence that the bombardment that occurred on Earth may have spurred on new life.

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Sugars in Meteorites Gives Clues to Origin of Life

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An international team has found sugars essential to life in meteorites, supporting the hypothesis that meteorite bombardment on ancient Earth may have assisted the origin of life with a supply of life's building blocks.

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It's a great introduction to how evolution works and how we came to be.

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Holly King - This film is a beautifully made film that opens the mind to the terrible impact that humans have on the ocean and climate change.

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Can we imagine a film that would change the way people look at the ocean? Can we explain simply, to everyone, the greatest natural mystery of our planet? And lastly, can we help our children believe in a better and more sustainable world tomorrow?
This is the triple challenge of a new cinema adventure signed by Yann Arthus-Bertrand and editor- in-chief Michael Pitiot, who brings with him the scientific missions of TARA, a unique pool of researchers, oceanographers and biolo- gists from several countries. Thanks to its astonishing photography, the film takes us on a magnificent and unprecedented journey into the heart of the least known regions of our planet. For more info visit http://www.goodplanet.org/

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Natalie Stratton - The Science behind the New Black Hole Pictures!

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Natalie Stratton - The Science behind the New Black Hole Pictures!

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Hannah Dunford-Sine: Climate Change and Public Health in Utah

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Hannah Dunford-Sine: Climate Change and Public Health in Utah

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Earth's concentric layers scale remarkably well to those of a peach. The atmosphere is proportionally as thick as the exterior fuzz. The crust corresponds to the skin, the iron core (although spherical rather than pointed) to the pit, and the rocky mantle, which constitutes eighty-four per cent of the volume of the planet, to the flesh of the fruit. The lower mantle is about eighteen hundred miles from Earth's surface-roughly the distance from Manhattan to Denver-but is less accessible and less known to us than the face of Mars. The deepest holes ever drilled, in a bizarre late-Cold War competition between NATO and the Soviet Union, barely pricked the skin; they went about eight miles down.

We know that the mantle is solid rock, contrary to various fanciful depictions in fiction and film, because, in the wake of major earthquakes, certain seismic waves that can be transmitted only through solids are detected on the opposite side of the globe. The time it takes these waves to traverse the mantle even provides information about the minerals that they encounter along the way. We also know that the mantle, although solid, is flowing in a slow, continuous roil, like the wax in a lava lamp. This convective overturning is the principal means by which Earth cools itself, and it sets the pace for the dance of the tectonic plates at the surface. It is also crucial to the existence of the magnetic field, which arises from the motion of liquid iron in the outer core. If the mantle didn't transport heat outward, there would be no vertical temperature contrast in the core to drive Earth's electromagnetic dynamo, which creates an invisible aura that extends many planetary diameters away-the scent, perhaps, of the peach. This halo protects us from solar wind and space radiation.

The character and behavior of the lower mantle have been the focus of one of the most quarrelsome modern debates in the geosciences. In the early nineteen-seventies, plate-tectonic theory-then only about five years old-had already gone far in explaining how geophysical phenomena, including earthquakes, volcanism, and mountain building, result from interactions between the major plates at their boundaries. The San Andreas Fault, the Himalayas, the Andes, Krakatoa, Vesuvius, and Mt. St. Helens all lie on plate boundaries. But there remained obvious exceptions, such as the prodigious volcanic activity at Hawaii and Yellowstone, both of which are in the far interiors of their plates. Not all the unrest, in other words, was at the margins.

In a modest paper published in the March 5, 1971, issue of Nature, the geophysicist Jason Morgan proposed that Hawaii and other isolated volcanic hot spots were surface manifestations of what he called mantle plumes-columns of hot (although not molten) rock, about a hundred miles in diameter, that rose from the core-mantle boundary and generated magma as they neared the surface. Morgan's article was rather thin on actual data, but his theory was consistent with a number of observations. First, lavas from Hawaii and similar archipelagoes, including Samoa, the Canaries, and dozens of others, differ markedly in their chemistry from those that erupt at the mid-ocean ridges, where plates diverge from each other. This suggests that they emanate from parts of the mantle that are distinct from those that produce ordinary seafloor basalt. Second, some island groups in both the Pacific and the Atlantic show a well-defined progression of ages. In the case of Hawaii, a string of successively older islands-and then an underwater mountain range, known as the Emperor chain-stretches to the northwest of the Big Island. Morgan's greatest insight was that this pattern could be a result of the northwestward motion of the Pacific Plate. Just as the bars on a typewriter strike a fixed point on a moving sheet of paper, the stationary mantle plume was leaving its embossment on the surface of the drifting crust.

Although Morgan's evidence was indirect, his idea quickly became reified, and most geologists forgot that mantle plumes were a conjectural concept rather than an observation. Over the next thirty years, in thousands of scientific papers, plumes and their putative effects were described, modeled, and categorized. They were invoked to explain a wide range of modern and ancient volcanic phenomena, including a billion-year-old rift beneath Lake Superior and the gigantic outpouring of lavas called the Siberian Traps, which may have triggered the Permian-Triassic extinction event, the most devastating in Earth's history.

But, in the early two-thousands, a vocal group of skeptics began raising questions. By this time, global seismology had progressed from merely delineating Earth's layers to measuring subtle variations in temperature or composition within the mantle using three-dimensional seismic tomography-analogous to medical CT scans. To the surprise of mainstream geoscientists, this method failed to reveal the expected columns of hot rock beneath oceanic islands. Even Hawaii, the paradigmatic plume site, did not seem to be fed by one.

Plume believers argued that seismic tomography lacked the resolution to detect relatively thin spindles of slightly warmer mantle; they remained certain that they would eventually spot the rara avis. Plume doubters, meanwhile, argued that the hypothesis was unscientific if no evidence could persuade its advocates to discard it. In their view, plumes were the phlogiston or the Sasquatch of geophysics, chimeras created to explain poorly understood phenomena that could be accounted for in other ways. A Web site, mantleplumes.org, was set up as an uncharacteristically raucous forum for exchanges between the two scientific camps.

Then, earlier this month, another paper in Nature reported what may be the first real glimpse of Morgan's elusive plumes, some forty-four years after he first postulated their existence. Using a new, computationally intensive method of seismic tomography, a pair of geoscientists at the University of California, Berkeley, captured the mantle's structure at unprecedented resolution. The images do at last reveal areas of warm rock emanating from the lower mantle far beneath Hawaii and other Pacific hot spots, but the columns are far larger in diameter than previously envisioned: these rare birds have stocky legs nearly five hundred miles wide. Another unexpected finding is that the plumes radiate only from certain areas along the core-mantle boundary, suggesting that they may be geochemical as much as thermal in nature. (Why the deepest mantle would be so chemically variable is a question that could become as contentious as the plume debate itself.) Finally, and perhaps most curiously, no deep plumes were detected beneath some archetypal hot spots, among them Yellowstone. The paper is so new that the scope of its influence is not yet clear. But it is a humbling reminder that this planet is one mysterious peach.

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Earth's concentric layers scale remarkably well to those of a peach. The atmosphere is proportionally as thick as the exterior fuzz. The crust corresponds to the skin, the iron core (although spherical rather than pointed) to the pit, and the rocky mantle, which constitutes eighty-four per cent of the volume of the planet, to the flesh of the fruit.

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Stand atop the steep white cliffs that surround the giant rivers of Siberia, and your feet will mark a pivotal point in the history of life on Earth: the 541-million-year-old geologic boundary between the Precambrian and Cambrian periods. The rocks below this dividing line contain scant fossil remains-ghostly impressions of soft-bodied organisms and a smattering of shelly forms. But break open any of the rocks just above the boundary, and they will be teeming with shells. A little higher up still, familiar fossil creatures such as trilobites appear. These changes document the so-called Cambrian explosion, one of the most significant, but still poorly understood, events in all of evolution.

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Stand atop the steep white cliffs that surround the giant rivers of Siberia, and your feet will mark a pivotal point in the history of life on Earth: the 541-million-year-old geologic boundary between the Precambrian and Cambrian periods.

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Why isn't anyone taking this problem more seriously? Unlikely isn't the same thing as impossible, even though it's human nature to conflate the two.

By

Mr. Walsh is the author of a forthcoming book on existential risks.

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Credit Credit Illustration by Zak Tebbal; Photographs via Getty Images

If you're planning to visit Yellowstone National Park this Labor Day weekend, I have good news: It is very, very, very unlikely that the supervolcano beneath it will erupt while you're there.

The Yellowstone supervolcano - an 8 out of 8 on the Volcanic Explosivity Index - has erupted three times over the past 2.1 million years, most recently 640,000 years ago. A Yellowstone eruption would be like nothing humanity has ever experienced.

First would come increasingly intense earthquakes, a sign that magma beneath Yellowstone was rushing toward the surface. Then magma would burst through the ground in a titanic eruption, discharging the toxic innards of the earth to the air. It would continue for days, burying Yellowstone in lava within a 40-mile radius.

A bad day at the park. But the devastation around Yellowstone would be just the beginning. Volcanologists believe a Yellowstone supereruption would bury large swaths of Colorado, Wyoming and Utah in up to three feetof toxic volcanic ash. Depending on the weather patterns, much of the Midwest would receive a few inches, too, plunging the region into darkness. Even the coasts - where a majority of Americans live - would most likely see a dusting as the ash cloud spread. Crops would be destroyed; pastureland would be contaminated. Power lines and electrical transformers would be ruined, potentially knocking out much of the grid.

That's just the United States. Modeling by meteorologists has found that the aerosols released could spread globally if the eruption occurred during the summer. Over the short term, as the toxic cloud blocked sunlight, global average temperatures could plunge significantly - and not return to normal for several years. Rainfall would decline sharply. That might be enough to trigger a die-off of tropical rain forests. Farming could collapse, beginning with the Midwest. It would be, as a group of researchers wrote in a 2015 report on extreme geohazards for the European Science Foundation, "the greatest catastrophe since the dawn of civilization."

Supervolcanoes like Yellowstone represent what are known as existential risks - ultra-catastrophes that could lead to global devastation, even human extinction. They can be natural, like supereruptions or a major asteroid impact of the scale that helped kill off the dinosaurs, or they can be human-made, like nuclear war or an engineered virus. They are, by definition, worse than the worst things humanity has ever experienced. What they are not, however, is common - and that presents a major psychological and political challenge.

Though asteroids get the press and the Michael Bay movies, existential risk experts largely agree that supervolcanoes - of which there are 20 scattered around the planet - are the natural threat that poses the highest probability of human extinction. But that's not the same thing as high. The probability of a supereruption at Yellowstone in any given year is 1 in 730,000.

But extremely unlikely isn't the same thing as impossible, even though it's human nature to conflate the two. What sets existential risks apart from everyday dangers isn't likelihood but consequence.

Let's say, as scientists have modeled, that a supereruption might kill 10 percent of the global population. Even if such eruptions occur roughly every 714,000 years - the low end of the frequency range - the death toll of that catastrophe equates to the expected loss of over 1,000 people annually, averaged out between now and when that supervolcano finally blows. If they occur roughly every 45,000 years - the high end of the range - that annual expected death toll jumps to some 17,000.

A bit of comparison helps here. Aviation accidents around the world caused 556 deaths in 2018. The Federal Aviation Administration alone spends more than $7 billion a year on aviation safety. Yet the United States spends only about $22 million annually on its volcano hazard programs - even though supervolcanoes, viewed over the longest of the long term, will kill far more people than plane crashes.

The difference, of course, is that aviation poses a risk that is relatively constant and known. There will probably never be a year in which no one dies in an aviation accident, but there will definitely never be a year in which 10 percent of the global population dies in a single plane crash. Yet that could happen with a supervolcano, an asteroid strike or a nuclear war.

We can reduce these existential risks. NASA has budgeted $150 million a year on planetary defense and could invest in space-based telescopes that might catch the asteroids we're missing now. It would cost about $370 million a year to bring the rest of the world up to the same level of volcanic monitoring that the United States has, which would lessen the chance of being surprised by a supereruption and thus reduce the potential death toll. Human-made existential risks like nuclear war or even artificial intelligence are, of course, well within our ability to prevent. Our species faces greater existential peril than we ever have before, but unlike through most of our existence, we now have the ability to protect ourselves.

What has happened before can and will happen again, eventually - but because we remain confined to the brief human time horizons of our own experience, we treat them as unreal. In doing so, we leave ourselves vulnerable to what we can't imagine.

A version of this article appears in print on , Section A, Page 27 of the New York edition with the headline: The Giant Volcano Under Our Feet. Order Reprints | Today's Paper | Subscribe

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Opinion | A Giant Volcano Could End Human Life on Earth as We Know It

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Why isn't anyone taking this problem more seriously? Unlikely isn't the same thing as impossible, even though it's human nature to conflate the two. By Mr. Walsh is the author of a forthcoming book on existential risks.

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Two centuries ago, a series of giant earthquakes rocked the tiny town of New Madrid, Missouri, collapsing chimneys and shaking houses more than 1000 kilometers away. It was even said that parts of the Mississippi River momentarily flowed backward as the riverbed heaved upward. Modern seismologists estimate that all three quakes in 1811-1812 registered above a 7.0 on the Richter scale-the largest known quakes east of the Rocky Mountains. Even today, the New Madrid Seismic Zone (NMSZ) generates more than 200 small tremors each year-and now a team of geophysicists thinks it knows what causes all the shaking.

In a new study, they use tomographic information about Earth's interior to show how blobs of dense rock from the lower crust rise up underneath the region. This dense rock gravitationally tugs on everything else around it, changing regional stresses in a way that makes some NMSZ faults more likely to slip. The approach not only confirms some scientists' suspicions about the driving force behind the NMSZ earthquakes, but it also opens the door to identifying other potentially deadly seismic areas. "We're interested in creating an honest-to-goodness map of where we think earthquakes will occur in the future," says lead author Will Levandowski, a geophysicist with the United States Geological Survey (USGS) in Golden, Colorado.

The NMSZ has been difficult to study. The region doesn't generate large earthquakes often enough for seismologists to have a detailed historical record, and there is no obvious mechanism driving the seismic activity. Elsewhere in the world, earthquakes tend to occur along active faults, like the San Andreas Fault in California, where two tectonic plates meet and push, pull, or slide against one another. But the NMSZ is smack in the middle of the quiet, solid North American plate. "Here, in the center of a plate, we don't have a theory that we can attribute the earthquakes to," says Christine Powell, a seismologist at the University of Memphis in Tennessee. "So in order to understand why they're occurring, you have to think outside the box."

One idea is that an ancient rifting event plays a role. Between 700 million and 540 million years ago, what is now the North American Plate was being pulled apart as it broke away from a supercontinent. The plate failed to split completely, but geologists think that the event left scars below the NMSZ: a buried rift zone, where the rocks are weak and fractured, over plutons-blobs of dense igneous rock-that themselves rose from an upwelling of unusually dense lower crust. Although this scenario has been proposed before, the researchers combined different data sets to provide strong support for the idea that the lower crust wells up beneath the NMSZ, they report in a study published 30 August in Geophysical Research Letters.

Key to the team's analysis was seismic velocity data from the U.S. Transportable Array, a traveling grid of seismometers that "listens" for low-level earthquakes and tracks the way their energy passes through the subsurface. The speeds of these seismic waves are related to the density of the rocks underground, and they allow researchers to construct a tomographic view of Earth's interior, like a computerized tomography scan.

The researchers also calculated how the presence of this dense lower crust would alter the stresses that drive earthquakes. The dense rocks' higher gravity pulls the surrounding land inward and downward. Already, the Mid-Atlantic Ridge, which runs down the middle of the Atlantic Ocean, is spreading and putting pressure on the North American plate, pushing it westward. But the high-density rocks below the NMSZ redirect that pressure downward, putting faults in the buried rift zone under significantly more pressure than the surrounding terrain. Under the right conditions, that pressure can be released as an earthquake.

Identifying potential earthquake triggers, however, is more difficult, and the researchers suggest that quakes might be set off by any number of factors. Between 16,000 and 10,000 years ago, for instance, geologic evidence suggests that the region became seismically active after the Mississippi River eroded too much soil from the ground above. Without the weight of the soil, faults that had been locked in place were unclamped, and could release energy through earthquakes.

Experts say the work could be used to explain why some areas are more prone to human-induced earthquakes, such as Oklahoma, which now sees more earthquakes than California. Fracking-related activities might be more likely to trigger an earthquake in an area that was already under stress, according to Roland Bürgmann, a geophysicist at the University of California, Berkeley. "I think the approach [the authors] take here is a useful one to bring to bear on that," he says.

In addition, the approach could be used to identify regions that are naturally under stress and prone to earthquakes. Levandowski suggests that using similar techniques, USGS might be able to find other vulnerable faults that haven't produced an earthquake in recorded history. Though Powell approves of the team's New Madrid analysis, she is skeptical of its broader application-in part because each of these seismic zones is unique. "I think it's going to take careful study and investigation to really sort out what we're seeing," she says.

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Scientists may have solved mystery of giant Midwest earthquakes

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Two centuries ago, a series of giant earthquakes rocked the tiny town of New Madrid, Missouri, collapsing chimneys and shaking houses more than 1000 kilometers away. It was even said that parts of the Mississippi River momentarily flowed backward as the riverbed heaved upward.

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Geologists tend to notice when rocks, especially big ones, are out of place. A few years ago, a group of researchers working in the Cape Verde islands, off West Africa, made a particularly jarring discovery-elephant-sized chunks of basalt and limestone that had formed at sea level and somehow ended up more than six hundred feet above, on a volcanic plateau on Santiago Island. The rocks constituted only the final few pages of an unusual narrative. What remained for the scientists, Ricardo Ramalho and his colleagues at Columbia University's Lamont-Doherty Earth Observatory, was to reconstruct the plot. Since it isn't easy to move more than seven hundred tons of stone at a time uphill, there were only a few possible protagonists. The one that they settled on was larger than life: a tsunami some eight hundred feet high, almost six times taller than the wave that hit Japan's Pacific Coast in 2011.

Back in the early nineteenth century, when geology was just emerging as a distinct science, such catastrophic explanations for modern-day features were fairly common. In those years, geologists in Europe and the Great Lakes region of North America began to take note of so-called erratic boulders, which were composed very differently from the local bedrock on which they rested. Monoliths of granite sat, illogically, on limestone; slabs of schist, improbably, on sandstone. The most reasonable interpretation of these foreign rocks, in the context of the contemporary understanding of Earth's history, was that they had been washed in by the waters of the Great Flood of Noah. Geologists called such flotsam "drift," and an early version of the geologic time scale included a period known as the Antediluvian-that is, "before the deluge."

Within a few decades, however, the maturing field of geology had distanced itself from Biblical accounts of Earth's evolution, and the incongruous rocks were reinterpreted as glacial hitchhikers, remnants of the Ice Age. Gradualistic explanations for geologic phenomena, informed by processes that could be observed today, became de rigueur; invoking the Noachian flood-or any catastrophic origin for rocks or landscapes-became a geologic taboo. (Even so, a vestige of the old flood paradigm persists in the name of an unglaciated region along the Upper Mississippi Valley: the Driftless Area.) The taboo finally lost some of its power in the nineteen-eighties, when it began to seem probable that a meteorite impact at the end of the Cretaceous Period had wiped out the dinosaurs. This unleashed into the scientific literature a pent-up flood of neocatastrophist papers, which sometimes veered toward the sensationalism of tabloids (with references cited, of course). Geologists were at last free to suggest that calamitous but infrequent events-powerful deluges, colossal landslides, gargantuan volcanic eruptions, supersonic impacts from extraterrestrial objects-did in fact play a role in shaping our world. Bad things sometimes happen to good planets.

In the past thirty years, the initial giddiness over extreme geology has subsided and the scientific standard for documenting ancient disasters has risen. When Ramalho's team began developing their theory about the Cape Verde rocks, there was a heap of skepticism to dispense with. At a latitude of just fifteen degrees north of the equator, the islands were never glaciated. This meant that the only other possible anti-gravity agent was water-namely, a very high and very powerful wall of it. The terrifying force of earthquake-generated tsunamis has already been seen twice in this new millennium, in Indonesia and Japan. But both of those island chains, unlike Cape Verde, lie hard up against the boundaries of tectonic plates, which occasionally lurch into motion, displacing immense volumes of seawater. Cape Verde is comparatively far from the edge of the African Plate. Whence, then, the wave?

Submarine earthquakes are not the only way to generate tsunamis. The sudden addition of a large mass to a body of water-like a chubby bully doing a cannonball into a swimming pool-can generate local waves of extraordinary height. In Cape Verde, the bully must have been an enormous quantity of rock, displaced suddenly from a significant elevation into the waters nearby. And there was a good candidate: the neighboring island of Fogo, thirty miles to the west, which has the shape of a half-eaten chocolate kiss. Whereas its west flank is smoothly conical, its east side is a ragged depression, pulled apart from the rest of the island in a great landslide. But did the slide happen slowly, as on the east flank of Kilauea, in Hawaii, which is collapsing under its own weight, or in a single cataclysmic failure?

Previous geological work on Fogo Island had constrained the timing of the slope failure to between a hundred and twenty-four thousand and sixty-five thousand years ago. Geologists routinely use naturally occurring radioactive isotopes-potassium-40, rubidium-87, uranium-238-to determine the ages of rocks. The question in this case, however, was not the age of the rocks but how long they had been lying in their present anomalous positions. Ramalho and his colleagues used an innovative new method of isotopic dating to establish a link between the landslide on Fogo and the boulders on Santiago. The technique relies on the fact that Earth is bombarded, constantly and invisibly, by cosmic rays-high-energy particles that hurtle toward the planet from deep space, mainly from distant supernovae. When these guts of ancient stars collide with atoms on rock surfaces, they produce small amounts of certain distinctive isotopes. Measure how much helium-3, for instance, has accumulated on a rock face and you know how long it has been exposed to cosmic radiation. In the case of the Santiago boulders, that was about seventy-three thousand years-well within the time window of the Fogo collapse.

So the rock-throwing protagonist has been conclusively identified, but what does the story mean for us? Is it a cautionary tale, a portent of looming disaster that should be added to our list of late-night worries? Probably not. Although the landslide on Fogo and the ensuing megatsunami would have been utterly devastating to nearby islands, it is not clear how far such a locally generated wave would have gone before dissipating. And, more to the point, the obsession with unlikely catastrophes is itself dangerous if it blinds us to the slow-motion disasters that are elapsing before our eyes. Envisioning a single deluge is easy; it takes imagination to perceive a sea change.

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Geologists tend to notice when rocks, especially big ones, are out of place. A few years ago, a group of researchers working in the Cape Verde islands, off West Africa, made a particularly jarring discovery-elephant-sized chunks of basalt and limestone that had formed at sea level and somehow ended up more than six hundred feet above, on a volcanic plateau on Santiago Island.

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The steel tycoon and philanthropist Andrew Carnegie, who was wealthier in his day than Bill Gates, Sam Walton, and Warren Buffett combined, amassed his fortune through brash business practices and the labor of thousands who toiled in his mills, but he actually owed everything to the work of ancient microbes.

Refined steel consists mostly of iron, with a little carbon thrown in for strength and toughness. Carnegie's steel, like almost all the steel ever produced in the world, was made with ore from Precambrian iron formations-stratified rock sequences, blood red and dull gray, that are typically mined in giant open pits. (One of the biggest, the so-called Grand Canyon of the North, is in Bob Dylan's hometown of Hibbing, Minnesota.) Whereas most rock types are timeless, in the sense that they come into being today in the same way that they have for aeons, iron formations are, in a manner of speaking, extinct. They provide an insider's account of a pivotal transition in Earth's history, a time of geochemical upheaval, between about 2.5 billion and 1.8 billion years ago, that is known as the Great Oxygenation Event. Prior to that planet-changing revolution, Earth's atmosphere was made up largely of carbon dioxide, water vapor, and nitrogen. Afterward, thanks to the industrious activity of photosynthesizing microorganisms such as cyanobacteria-whose modern descendants are often called, with less than due respect, pond scum-the air was full of free oxygen.

The ancient iron formations share many characteristics with modern limestones, which suggests that they accumulated in a marine environment. In today's oceans, iron is in such short supply that it is a limiting nutrient-an essential element whose scarcity holds biological productivity in check. (A controversial climate-engineering scheme is even based on this fact; the idea is that if the oceans were fertilized with iron powder, plankton would bloom enthusiastically and then die, sinking to the ocean floor and sequestering large amounts of carbon there without, fingers crossed, wreaking havoc on the rest of the marine biosphere.) The primordial oceans, by contrast, must have been awash with iron. The richness of the rock formations-imagine all the steel in cars, cutlery, airplanes, buildings, bridges, and railroads-attests to that.

It was oxygen, a disruptive newcomer to the aquatic economy, that permanently altered the rules about what could and could not be present in seawater. Before the Great Oxygenation Event, iron was able to dissolve in the oceans, commingling invisibly with sodium, chlorine, and other ions. But, when oxygen began to make inroads, even in concentrations far lower than present levels, it found the iron atoms, bonded itself to them, and pulled them to the seafloor. Oxygen, and the microbes that manufactured it, purged the oceans of iron literally by rusting it out. Red was the color of the revolution.

The iron formations precipitated from seawater, but where did the dissolved iron come from in the first place? Geologists have generally pointed to deep-sea volcanic vents like the modern Mid-Atlantic Ridge. Here, incandescent magma from the mantle meets cold seawater, and metallic brines gush forth from the rock chimneys known as black smokers. But a paper published in July in the Proceedings of the National Academy of Sciences suggests an alternative source. Up to half of the iron in iron formations, a group of geochemists at the University of Wisconsin argues, may have come originally from land. According to their theory, iron from continental rocks, which had become newly reactive in the oxidizing atmosphere, was carried by rivers to the ocean, where it was released into seawater by non-photosynthesizing microorganisms-the comrades of the cyanobacteria that were transforming the air.

The study examines the iron formations of the Hamersley Basin, in western Australia. Like most elements, iron comes in a range of flavors, known as isotopes, which vary in mass and stability. Iron from the mantle, released at black smokers, has a predictable ratio of iron-56 (full fat) to iron-54 (lite), but in the Hamersley rocks the ratio is skewed; the iron is, on average, lower-fat than expected. According to the Wisconsin group, this is evidence of biological activity, since iron-54 is easier for living things to metabolize than iron-56. In particular, they suggest that the isotope ratios are the signature of microbes that colonized the shores of the primordial ocean and found a way to make an opportunistic living from the incoming river sediments. These single-celled entrepreneurs might have gained energy by stripping oxygen from the land-derived iron-an electron-transfer reaction that anticipated the first battery by two billion years. The bacterial middlemen then discarded the unwanted iron, disproportionately enriched in the lighter isotope, into the water, where it was again hunted down by oxygen and rusted out. In other words, much of the iron in iron formations may come pre-owned.

This conclusion is not accepted by everyone in the surprisingly vigorous and contentious field of Precambrian biogeochemistry. Skeptics point out that iron isotopes can be sorted by mass through non-biological processes, as when bodies of water with different chemistries mix, and that the iron-54 signature in the Australian rocks could just as easily be due to the removal of heavy iron as to the addition of light, in the same way that the average income of a neighborhood could be reduced by a few rich people moving away rather than an influx of lower-income families. Whether or not a second group of microbial workers was involved in the manufacture of iron formations, though, the fact that the question can be posed at all reveals how far geology has come in learning the dialects of even very old rocks that formed on an Earth we would find alien.

In some strange way, Andrew Carnegie was not unlike the cyanobacterial minions to which he was unknowingly indebted. Through ruthless capitalism, and inexorable Darwinism, both concentrated huge stockpiles in their time and unilaterally changed the rules for their contemporaries. Yet both ultimately left behind egalitarian legacies of shared riches-libraries, Pell grants, public broadcasting, and free oxygen for all.

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The steel tycoon and philanthropist Andrew Carnegie, who was wealthier in his day than Bill Gates, Sam Walton, and Warren Buffett combined, amassed his fortune through brash business practices and the labor of thousands who toiled in his mills, but he actually owed everything to the work of ancient microbes.

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Among Earth's planetary neighbors, Mars has been the one on which humanity has most often, and most variously, projected its hopes and fears. In the Greco-Roman and Norse pantheons, blood-red Mars (a.k.a. Ares or Tyr) was the god of war, a role we still celebrate each Tuesday-although the etymological connection is more obvious in Spanish ( martes) and Norwegian ( tirsdag) than in English. To Percival Lowell, the scion of a nineteenth-century Boston family, who was wealthy enough to build himself a world-class astronomical observatory, Mars was the tragic site on which a dying race of civil engineers built an elaborate, if illogically designed, canal system, in a desperate effort to redirect water from the polar ice caps to equatorial cities. (The fact that Lowell also described reticulated patterns on the surface of Venus, which is perennially cloud-shrouded, has driven modern astronomers to suggest that his telescope lens was actually acting as an ophthalmologic instrument, causing him to see the shadows of the blood vessels in his eye.)

The redoubtable inventor Nikola Tesla was so convinced that he had detected radio signals from Mars with his receiver array, at the top of Pikes Peak, in Colorado, that in 1924 he persuaded the U.S. government to hold a National Radio Silence Day, during which broadcasters were ordered to cease transmissions for five minutes every hour. To H. G. Wells and many others, Mars has been the cradle of malevolent invading aliens-stand-ins, in different decades, for (red) communists, immigrants, nonconformists, and other categories of the despised. Even latter-day NASA scientists have fallen prey to the allure of Mars as a possible crucible for life. In 1996, the agency held a press conference prematurely announcing the discovery of fossilized microbes in a Martian meteorite. Subsequent peer review of their analyses led to an embarrassing series of hedges and retractions.

Yet the actual story of Mars is weirder, grander, and in some ways more terrifying than any of the fictions that humans have spun. Although the planet has a diameter about six-tenths that of Earth and weighs in at only eleven per cent of Earth's mass, it is in other ways a place of extremes. Its entire top seems to have been blown off in an early impact, resulting in a so-called crustal dichotomy: Mars's northern hemisphere is at an average elevation one and a half miles lower than the southern. The planet is scarred by a vast chasm, the Valles Marineris, which is five times longer and two and a half times deeper than the Grand Canyon. Superimposed on the continental United States, it would stretch from the Carolinas to California.

Diminutive Mars is also home to the solar system's most gargantuan volcano, Olympus Mons. It has a footprint the size of Arizona and a height almost three times that of the Earth's largest volcano, Mauna Loa. Other than an unexplained near-vertical four-mile-high scarp around its base, Olympus Mons has the gentle slopes that are typical of terrestrial shield volcanoes, like those in Hawaii, which are built of basalt. But Olympus Mons is just one of many overgrown volcanoes on a high lava plain called the Tharsis Bulge. The eruptions that formed the Tharsis Bulge, driven by convective overturn in the Martian mantle, transferred so much mass from the interior to the exterior of Mars that at some point the volcanic carbuncle was large enough to alter the planet's rotation. The huge pile of basalt, formed initially at high latitude, caused Mars to tip over on its side, even as it continued rotating on the same axis with respect to its path through space. Areas that once were close to the poles now lie near the equator-as if northern Greenland became the new Bahamas-a phenomenon known as true polar wander.

The growth of the Tharsis Bulge and the resultant listing of the planet were previously thought to have happened very early in Mars's development, more than three and a half billion years ago, during the Noachian Era. (Because Mars has a very different geologic-or, to purists, areologic-history than Earth, it does not make sense to use the Earth-based geologic timescale, whose divisions correspond to important chapters in our planet's evolution.) The use of the name "Noachian" for a Martian time period may seem rather ironic, given the strenuous efforts of geologists to distance their discipline from biblical floods, but it is clear from fossilized drainage networks on the Martian surface that Mars once did have abundant running water. The distribution of these ancient river systems should reflect both latitudinal variations in precipitation and the regional slopes created by the Tharsis Bulge, if it indeed existed at the time the rivers flowed.

A new study in this week's issue of Nature, by the geoscientist Sylvain Bouley and six of his colleagues in France, Senegal, and the United States, suggests that some of this history may need to be rewritten. The authors argue that the Tharsis-induced planetary toppling occurred well after the Noachian, and that the decline of an active water cycle on the planet coincided with the end of vigorous volcanism. When they restored Mars to its pre-polar-wander position, and also removed the flattening related to its spin on its present-day axis, they found that the ancient valley networks define a band of streams that flowed from the southern hemisphere toward the northern lowlands. This is consistent with precipitation patterns predicted by climate models of a Mars without the Tharsis Bulge, on which the crustal dichotomy dictated drainage patterns. Percival Lowell was right about Martian water transfer, but he had the directions, dates, and responsible parties all wrong.

The new study's conclusions are satisfying in that they suggest a coherent story of the gradual decline of Mars as an active planet. On rocky planets like Earth and Mars, volcanic emissions are the primary source of atmospheric gases, including water vapor. A body as small as Mars, with a weak gravitational pull, will quickly lose its atmosphere to space without constant volcanic replenishment. It makes sense, then, that the valley networks on Mars-records of halcyon days when there were rains and rivers-would have taken shape while the great Tharsis volcanoes were in their formative stages. By the time the volcanoes got large enough to affect the planet's rotation, they were on their way to dormancy. The planet had cooled, the interior ceased convecting, and the great volcanoes exhaled their last breaths. Martian waters slowly dissipated to space, and the disfiguring Tharsis lump pulled the dying planet over, carrying the abandoned river valleys to foreign latitudes.

There is pathos in the story of a planet that would seem to have had the promise of a much longer biography. In contrast to Earth's geologic timescale, whose divisions get finer as we approach the present day, the past three billion years on Mars, during which little has changed, are considered one long era (the Amazonian, another ironic choice of names). Earth, meanwhile, had the advantage of its greater size and gravity, but it also struck fortuitously upon a marvellous system for recycling and sequestering water and other atmospheric gases for later use-namely, plate tectonics, which, via the subduction of ocean crust, keeps the interior and exterior of our planet connected in a way that Mars never had time to try.

The stories that humans have long told about Mars-most of them narcissistically anthropocentric-have all missed the point. The most important message from Mars may be what it is telling us about how it parted ways long ago with an even stranger planet known as Earth.

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Among Earth's planetary neighbors, Mars has been the one on which humanity has most often, and most variously, projected its hopes and fears. In the Greco-Roman and Norse pantheons, blood-red Mars (a.k.a. Ares or Tyr) was the god of war, a role we still celebrate each Tuesday-although the etymological connection is more obvious in Spanish ( martes) and Norwegian ( tirsdag) than in English.

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Residential land zoned for:

Single-family zoning is practically gospel in America, embraced by homeowners and local governments to protect neighborhoods of tidy houses from denser development nearby.

But a number of officials across the country are starting to make seemingly heretical moves. The Oregon legislature this month will consider a law that would end zoning exclusively for single-family homes in most of the state. California lawmakers have drafted a bill that would effectively do the same. In December, the Minneapolis City Council voted to end single-family zoning citywide. The Democratic presidential candidates Elizabeth Warren, Cory Booker and Julián Castro have taken up the cause, too.

A reckoning with single-family zoning is necessary, they say, amid mounting crises over housing affordability, racial inequality and climate change. But take these laws away, many homeowners fear, and their property values and quality of life will suffer. The changes, opponents in Minneapolis have warned, amount to nothing less than an effort to " bulldoze" their neighborhoods.

Today the effect of single-family zoning is far-reaching: It is illegal on 75 percent of the residential land in many American cities to build anything other than a detached single-family home.

That figure is even higher in many suburbs and newer Sun Belt cities, according to an analysis The Upshot conducted with UrbanFootprint, software that maps and measures the impact of development and policy change on cities.

If this moment feels like a radical shift, said Sonia Hirt, a professor at the University of Georgia's college of environment and design, it was also a radical shift a century ago when Americans began to imagine single-family zoning as possible, normal and desirable. That shift led Minneapolis to look like this:

Minneapolis's new policy will end single-family zoning on 70 percent of the city's residential land, or 53 percent of all land. The Upshot used public zoning data compiled by UrbanFootprint to calculate this and draw similar maps for 10 other American cities.

Zoning codes vary significantly by city. But in each place, we sought to identify codes devoted to detached single-family homes, grouping rowhouses more common in older East Coast cities like Washington and New York into a second category covering all other housing types. (The earliest American zoning advocates clearly did not put rowhouses in the same category: A home, they believed, was a house " which one can drive a yoke of oxen around.")

Many cities allow additional housing in nonresidential zones: for instance, in apartments built over offices or stores. These maps highlight the land exclusively set aside for housing.

Such maps reflect the belief that denser housing can be a nuisance to single-family neighborhoods just as a factory would be. That conviction is at least as old as the 1926 Supreme Court decision that upheld zoning in America.

Apartments, the court warned, block the sun and air. They bring noise and traffic. They act as a parasite on single-family neighborhoods - "until, finally, the residential character of the neighborhood and its desirability as a place of detached residences are utterly destroyed."

Today, the very density that the court scorned is viewed by environmentalists as an antidote to sprawling development patterns that feed gridlock and auto emissions. It's viewed by planners as an essential condition to support public transit, and by economists as the best means of making high-cost cities more affordable.

Single-family zoning "means that everything else is banned," said Scott Wiener, a California state senator, speaking this spring at the Brookings Institution in Washington. "Apartment buildings - banned. Senior housing - banned. Low-income housing, which is only multi-unit - banned. Student housing - banned."

Cities regularly "upzone" individual neighborhoods or properties to allow more housing options. Minneapolis's remarkable approach was to upzone every single-family neighborhood at once. That was the fairest solution, officials argued.

"If we were going to pick and choose, the fight I think would have been even bloodier," said Heather Worthington, director of long-range planning for the city.

Even so, some residents vocally opposed the change, and the city collected 20,000 public comments on the broader plan that included the zoning proposal. The City Council ultimately voted for it, 12-1. If, as expected, a regional council approves it this year, duplexes and triplexes will be allowed citywide on what are now single-family lots.

The lesson of Minneapolis, said Salim Furth, an economist at the conservative Mercatus Center, is that a single, sweeping edit to these maps may be politically easier than block-by-block tweaking.

Over time, if just 5 percent of the largest single-family lots in Minneapolis - lots of at least 5,000 square feet - converted to triplexes, that would create about 6,200 new units of housing, according to UrbanFootprint. If 10 percent of similar-sized lots in San Jose, Calif., added a second unit, the city would gain 15,000 new homes.

"If you want to have the suburban American lifestyle, that will still be on offer," Mr. Furth said. "What we're really trying to change is that that has become so universal that there's not much space left for anything else."

A moment of crisis

While zoning remains invisible to many people, the problems it's connected to increasingly are not.

"Every community has to have a moment of crisis that eventually makes you pay attention to certain things," said Taiwo Jaiyeoba, the planning director for Charlotte. "You knew they were there, but there was no impetus or motivation to address it."

The crisis struck in Charlotte in 2014, he said, when a national study ranked the region as having among the worst prospects in the country for poor children. Public meetings and task force reports followed, focused on Charlotte's racial and economic segregation.

Zoning laws helped cement those patterns in cities across the country by separating housing types so that renters would be less likely to live among homeowners, or working-class families among affluent ones, or minority children near high-quality schools.

Mr. Jaiyeoba believed Charlotte had to change its zoning to become more equitable. But that argument seemed abstract until Minneapolis acted on it. This spring, Mr. Jaiyeoba invited Ms. Worthington to town to explain the idea in a public forum. Charlotte doesn't have a formal proposal yet, but he hopes elected officials will lead the city toward one.

Ms. Warren, Mr. Booker and Mr. Castro, who have similarly emphasized racial inequality, have proposed leveraging federal money to nudge cities to change zoning laws.

On the West Coast, a severe housing shortage and environmental concerns loom larger. Single-family zoning leaves much land off-limits to new housing, forcing new supply into poorer, minority communities or onto undeveloped land outside of cities.

In California, a bill by Mr. Wiener affecting zoning statewide has been stalled by homeowners and local officials who object to state interference in their communities. The bill would allow more density around transit and jobs centers. It would also permit single-family homes to be subdivided into as many as four units, and multi-unit buildings to go up on vacant lots in single-family neighborhoods.

Oregon's bill would allow options as dense as fourplexes across cities larger than 25,000 people and within metropolitan Portland, and it would permit duplexes in towns of at least 10,000. Portland has spent several years planning its own zoning changes to single-family neighborhoods, amid opposition by homeowners.

But the prospects for such ideas have improved from even two years ago.

"Wages are up, people are working, unemployment is way down - and people can't find a place to live," said Tina Kotek, the speaker of the Oregon house and the author of the new bill. The dissonance between those facts, she said, is changing the politics of zoning.

The state has long regulated "urban growth boundaries" intended to protect farmland and green space beyond cities. But even so, many communities have been reluctant to grow denser inside those boundaries. In Oregon, the joke goes, people hate sprawl and density.

"At some point," Ms. Kotek said, "something's got to give."

A return to history

High-level arguments about the environment, affordable housing or equity invariably meet more prosaic objections: What if some neighborhoods lack enough parking? Or if one person's development shades another's backyard? How are apartment buildings more environmentally friendly if they replace all the trees?

"What we're selling here in Minneapolis - or what our planning department and our city council are selling - is that we're new, we're state of the art, we're cutting-edge, we're virtue signaling," said Lisa McDonald, a former Minneapolis City Council member and part of a group opposing the city's plans.

In reality, she said, Minneapolis is giving itself away to developers. They'll build more market-rate housing, she said. But she doubts the city will get much more affordable housing - or less racism, more equity or a fairer society. Beware those promises, she warns other cities.

People elsewhere say their legitimate fears about traffic or the environment have been mischaracterized, caught up in an emotional debate over race and fairness. Martin Henry Kaplan, an architect in Seattle whose neighborhood association sued to block looser regulations on "accessory dwelling units," recalled as a child that his parents couldn't buy a house in a neighborhood where Jews weren't welcome.

"I'm old enough to actually have lived in some of that," said Mr. Kaplan, who is 70. But he does not see bigotry behind the objections to upzoning today. "Maybe I'm wrong, but I've grown up here, I have tons of friends in every neighborhood across the city, and I don't get the sense that anybody thinks like that."

Policies originally conceived in part to be exclusionary, he said, can still be useful toward nonexclusionary ends, like ensuring that neighborhoods don't have more residents than their sewers can handle, or that families who sink their savings into a home know what to expect around it.

"Zoning has a role," Mr. Kaplan said, "in addressing land-use regulations for the common good."

This debate is partly about the scale of that common good, given that the common good desired within many single-family neighborhoods conflicts with the common good across whole cities where housing is scarce or segregated. In an uneasy compromise between those interests, Seattle in March upzoned 6 percent of its single-family land.

Cities have typically prioritized single-family homeowners above other groups, with the old belief that dense housing hurts their property values, said Andrew Whittemore, a professor of city and regional planning at the University of North Carolina-Chapel Hill. Evidence supporting that belief is mixed, but Mr. Whittemore suggests it's the wrong thing to focus on.

"Why is it the job of a government to see that a housing unit accumulates as much value as possible?" he said. "I think the purpose of zoning is to prevent harm. Planners shouldn't be wealth managers. But they effectively are in every municipality in the country."

Citywide proposals to change these maps are not as unprecedented as they appear today. In 1960, Los Angeles had the zoned capacity for about 10 million people, according to Greg Morrow at the University of California, Berkeley. By 1990, Los Angeles had downzoned to a capacity of about 3.9 million, a number that is only slightly higher today. As a result, the city's actual population is now uncomfortably close to what it legally has room for; residents of Los Angeles today effectively fill about 93 percent of the city's zoned capacity, by Mr. Morrow's calculation.

Advocates who want to curb single-family zoning, he said, are not pushing an idea that has never been tried before. They're lobbying for a return to the past.

Many Minneapolis blocks today date to before the 1920s, with duplexes or small apartment buildings next to single-family homes. For years, those older buildings have been considered " nonconforming," as the law changed around them. Under Minneapolis's new plan, that distinction will end, too.

Mixed-use zones and other nonresidential districts, gray on these maps, may allow housing in addition to other uses, like offices. The following cities allow accessory dwelling units like garage apartments or in-law suites on some or all single-family lots, typically with many restrictions: Minneapolis, Washington, Charlotte, San Jose, Seattle, Portland and Los Angeles. Some cities include adjacent land uses like churches, schools, parks or cemeteries in residential zones.

Detailed New National Maps Show How Neighborhoods Shape Children for Life

Some places lift children out of poverty. Others trap them there. Now cities are trying to do something about the difference.

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Cities Start to Question an American Ideal: A House With a Yard on Every Lot

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Residential land zoned for: Single-family zoning is practically gospel in America, embraced by homeowners and local governments to protect neighborhoods of tidy houses from denser development nearby. But a number of officials across the country are starting to make seemingly heretical moves.

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More than half a billion years ago, our planet was a giant snowball hurtling through space. Glaciers blanketed the globe all the way to the equator in one of the mysterious "Snowball Earth" events geologists think occurred at least twice in Earth's ancient past. Now, scientists have found that the final snowball episode likely ended in a flash about 635 million years ago-a geologically fast event that may have implications for today's human-driven global warming.

The ice, which built up over several thousand years, "melted in no more than 1 million years," says Shuhai Xiao, a paleobiologist at Virginia Polytechnic Institute and State University in Blacksburg who was part of the team that made the discovery. That's the blink of an eye in our planet's 4.56-billion-year history, suggesting the globe reached a sudden tipping point, Xiao says. Although the team doesn't know for certain what caused it, carbon dioxide emitted by ancient volcanoes may have triggered a greenhouse event, causing the ice sheets to thaw rapidly.

To shine light on the pace of deglaciation, Xiao and colleagues dated volcanic rocks from southern China's Yunnan province. These were embedded below another kind of rock called a cap carbonate-unique deposits of limestone and dolostone that formed during Snowball Earth's shutdown in response to high levels of carbon dioxide in the atmosphere. Using radiometric dating techniques, the team found the volcanic rocks were 634.6 million years old, give or take about 880,000 years. Alone, this single new date couldn't reveal the speed at which the melting happened. But in 2005, a different team of scientists dated volcanic rocks from above a similar cap at a different location-in China's Guizhou province. They were dated to 635.2 million years, give or take 570,000 years.

Together, the two samples suggest the melting event was a quick thaw of about 1 million years, Xiao and his colleagues wrote last month in Geology. The key, Xiao explains, is that these two dates are far more precise than those of past samples, with error bars of less than 1 million years. Those error bars essentially bracket the period in which the cap carbonates formed-and, thus, bound the period of the final Snowball Earth thawing event. Because previously discovered samples have error bars of several million years or more, Xiao says these new dates are the first that can be used to calculate the pace of melting with any certainty.

However, because the two new samples come from southern China, they don't paint a global picture of the ancient thaw, says Carol Dehler, a geologist at Utah State University in Logan. To do that, scientists would need to find datable volcanic rocks from other parts of the world, which are about "as common as unicorns," she jokes. But, she adds, they might be out there "waiting to be discovered."

Meanwhile, understanding the nature of these ancient glaciations could help scientists dealing with climate change today: "I think one of the biggest messages that Snowball Earth can send humanity," Dehler says, "is that it shows the Earth's capabilities to change in extreme ways on short and longer time scales."

doi:10.1126/science.aax5539

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Ancient 'Snowball Earth' thawed out in a flash

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More than half a billion years ago, our planet was a giant snowball hurtling through space. Glaciers blanketed the globe all the way to the equator in one of the mysterious "Snowball Earth" events geologists think occurred at least twice in Earth's ancient past.

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ORLANDO, FLORIDA- An estimated 18 million Americans are at risk of lead leaching from old pipes in their homes and city water systems; such exposure can cause neurological problems in adults and-in children-delayed or stunted brain development. The impact of such leaching was on full display in 2015 in Flint, Michigan, when officials changed the source of city water to save money. The new water increased corrosion in the city's lead pipes, releasing lead into the drinking water and exposing tens of thousands of children.

To prevent lead from leaching, many cities add negatively charged compounds called phosphates to their water source. When the phosphates encounter positively charged lead ions in the water, the two react to create lead phosphate, an insoluble minerallike crust that builds up on the inside of the pipe, sealing it and preventing additional lead ions from leaching into the water. But depositing that crust, a process known as scaling, can take years.

Now, researchers in California have found a way to speed this process 500-fold, by simply threading a wire down the inside of the pipe and temporarily switching on an electric current. The current actually causes more lead ions to leach into the water, but those ions then react with the phosphates to build up the mineral barrier. Once locked in place, the mineral scaling causes lead levels leaching into the pipe to drop by 99%, the researchers report today here at the semiannual meeting of the American Chemical Society. The process can create a scale in just hours, rather than months or years.

So far, the potential fix has only been tested in the lab. Later this year, the researchers plan to field test it at a school in Oakland, California, where normal scale buildup isn't happening in the building's lead pipes. If the new method works, it could offer cities around the world-including Flint-a fast and cheap way to seal lead in their aging pipes without having to dig them out of the ground.

doi:10.1126/science.aax5712

Bob is a news reporter for Science in Portland, Oregon, covering chemistry, materials science, and energy stories.

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To seal off dangerous lead pipes, just add electricity

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ORLANDO, FLORIDA- An estimated 18 million Americans are at risk of lead leaching from old pipes in their homes and city water systems; such exposure can cause neurological problems in adults and-in children-delayed or stunted brain development. The impact of such leaching was on full display in 2015 in Flint, Michigan, when officials changed the source of city water to save money.

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VIENNA- Braving a raft of icebergs, a scientific drill ship has recovered the first deep sediment cores from the Amundsen Sea, where the massive Antarctic ice sheet is rapidly melting. The 800-meter-long records, described for the first time last week at the annual meeting of the European Geosciences Union here, contain several million years of history of the West Antarctic Ice Sheet. "It's a very strategic place to drill," says Florence Colleoni, a paleoclimate and ice sheet modeler at the National Institute of Oceanography and Experimental Geophysics in Sgonico, Italy.

Geoscientists suspect the ice sheet has previously collapsed, raising sea level around the world by several meters. By searching the cores for clues to the timing and extent of these dramatic, ancient events-and the ocean conditions that led to them-scientists can better assess how much the ocean might rise now and how quickly, Colleoni says. "This is really important for our future."

The West Antarctic Ice Sheet is particularly vulnerable to melting from warming ocean waters because its base lies below sea level. Computer models vary in their predictions of how quickly it will disappear, but some predict it will be responsible for driving up global sea levels by a meter or more over the next century. To improve those models, scientists want to learn about the behavior of the ice sheet during the mid-Pliocene, 3 million to 4 million years ago, when temperatures were like today's, says Rob DeConto, a glaciologist at the University of Massachusetts in Amherst who studies the ice sheet. The new cores, he says "will have a lot to bring to the table."

The JOIDES Resolution, a research ship operated by the International Ocean Discovery Program, spent January to March in the Amundsen Sea, off the coast of West Antarctica. The hope was to drill sediment cores in five places, ranging from the continental rise toward the shallower waters of the continental shelf. Unfortunately, the ship could not reach the drill sites closer to Antarctica because it is not equipped to travel through ice and sea ice (which grows and retreats each year) extended farther out than usual. Even in the open water, avoiding the many icebergs meant less time to drill in other places. "We simply had bad luck this year," says Karsten Gohl, a geophysicist at the Alfred Wegener Institute in Bremerhaven, Germany, and a leader of the cruise. "Despite the icebergs, we still got fantastic cores."

The cores were retrieved from the two sites in deeper water. At each site, the JOIDES Resolution had to drill multiple holes-whenever an iceberg drifted too close for comfort, the crew aborted the drilling-but they eventually collected hundreds of meters of sediment. One set of cores, from seven holes, was drilled through a drift, a dune on the sea floor. Currents sweeping around the continent continuously deposited sediment there and with those records geologists can determine whether Earth was in an ice age. During glacial periods, the currents tend to be vigorous, leading to thin layers of fine sediments. But when Earth is warmer and the ice sheet disappears, the ocean circulations around Antarctica relax and sediment is deposited without obvious fine layers.

Crucially, the sediment cores preserve a complete history: The Amundsen Sea at that site is 4000 meters deep, so the seafloor dune was safe from storms that can erode sediment in shallower water. "The fact that you have a continuous record from this margin is really exceptional," Colleoni says. Tiny fossils indicate that the oldest parts of the core date back to the late Miocene, about 6 million years ago, dates that were confirmed by the patterns of magnetism recorded in the sediments.

The other site, which yielded cores from four holes, is some 60 kilometers away from the first one and close to a submarine channel. When deep currents travel down such channels, they often carry and deposit sediment that was eroded from nearby land. (The currents passing over the drift, in contrast, are thought to carry sediment from much farther away.) Researchers can trace the origin of sediment by studying the mineralogy and chemistry of individual grains, comparing them to rocks on land. By combining various lines of evidence, the team hopes to infer when the ice sheet retreated.

The cores from both sites also contain pebbles or larger stones that were transported from the continent by icebergs. An abundance of such stones is another, more straightforward sign of a retreating ice sheet that is calving many icebergs.

A key question is how the waxing and waning of the ice sheet correlates with records of ocean temperatures, which the researchers can estimate from the abundance of certain chemical isotopes in the fossilized shells of tiny organisms called foraminifera.

The research team expects to spend the next 2 years coaxing this history out of the cores. But their analysis of them began on board the ship, as soon as they emerged from the drill rig. "The JOIDES Resolution is an extraordinary floating lab," says Julia Wellner, a sedimentologist at the University of Houston in Texas who co-led the expedition. An x-ray machine was installed on board for the first time to look inside the cores for pebbles dropped by melting icebergs. In addition to counting the pebbles, the team has found a variety of layers, sediment types, and patterns of deposition that reveal the conditions of the ocean through time. "That was the truly exciting thing about this cruise," Wellner says. "I had a little bit of dread that we would drill 800 meters of the same thing."

doi:10.1126/science.aax7040

Erik is a reporter at Science, covering environmental issues and UK research.

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Newly drilled sediment cores could reveal how fast the Antarctic ice sheet will melt

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VIENNA- Braving a raft of icebergs, a scientific drill ship has recovered the first deep sediment cores from the Amundsen Sea, where the massive Antarctic ice sheet is rapidly melting. The 800-meter-long records, described for the first time last week at the annual meeting of the European Geosciences Union here, contain several million years of history of the West Antarctic Ice Sheet.

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The state of biodiversity and ecosystems is at its most perilous point in human history and the decline is accelerating, warns a landmark assessment released today. But the hope is that the bleak assessment-crafted by hundreds of scientists and historic in its depth and breadth-will finally persuade governments and others of the need to change course and prevent further harm to the ecological systems that provide for human well-being. "What's at stake here is a livable world," says Robert Watson of the University of East Anglia in Norwich, U.K., who chaired the organization that produced the report.

Only transformative changes to economic, political, and social systems will allow nations to meet agreed targets for nature conservation, the authors conclude. The core message is "quite radical," says Georgina Mace, an ecologist at University College London who reviewed the assessment. "You have to prioritize nature and nature's benefits to people in everything you do."

The report confirms "that we can't just preserve, we must reverse the trend by increasing biodiversity locally, regionally, and globally," said Alexandre Antonelli, director of the Royal Botanic Gardens, Kew in the United Kingdom, in a statement.

The report comes from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), based in Bonn, Germany, which includes representatives from more than 100 countries. More than 450 experts from around the world were involved in drafting the 1800-page report over 3 years. They reviewed some 15,000 scientific papers and other sources of data on trends in biodiversity and its ability to provide what are known as ecosystem services or nature's contributions to people: everything from food and fiber to clean water and air.

Many species are declining, the report notes. Out of 8 million known species of animals and plants, about 1 million are under threat of extinction, including more than 40% of amphibian species and a third of marine mammals. Even more are declining in numbers: Since 1900, native species have become, on average, about 20% less abundant. Measures of the extent and condition of natural ecosystems have declined 47% since the earliest estimates and many are deteriorating by 4% every decade.

The report highlights other metrics of the decline of nature and its human domination. They include:

Seventy-five percent of land has been "severely altered" by human activities.

More than a third of land and almost 75% of freshwater is used for crops or livestock.

The extent of living coral reef has dropped by perhaps half since the 1870s.

One hundred million hectares of tropical forest have been destroyed between 1980 and 2000.

Wetlands, which provide clean water and fish, are being destroyed three times faster than forests.

Plastic pollution has increased 10-fold since 1980 and 300 million to 400 million tons of industrial waste are dumped each year.

Coasts are marred by some 400 low-oxygen dead zones, equivalent to the area of the United Kingdom.

"The message is unfortunately very alarming," says Hesiquio Benitez of the National Commission for the Knowledge and Use of Biodiversity in Mexico City, a national delegate who voted to approve the report. "We're reaching the limits of the planet."

For the first time at a global scale, the report has ranked the causes of damage. Topping the list, changes in land use-principally agriculture-that have destroyed habitat. Second, hunting and other kinds of exploitation. These are followed by climate change, pollution, and invasive species, which are being spread by trade and other activities. Climate change will likely overtake the other threats in the next decades, the authors note. Driving these threats are the growing human population, which has doubled since 1970 to 7.6 billion, and consumption. (Per capita of use of materials is up 15% over the past 5 decades.) The report also includes perspectives from indigenous and local communities to a greater extent than before. Lands managed by indigenous peoples are declining less quickly than elsewhere, but 72% of indicators developed by such communities show deterioration of nature.

There are a few bright spots, mostly the increasing creation of nature reserves and marine protected areas. But the progress is not nearly enough to meet most of the international conservation targets that nations set in the Convention on Biological Diversity in 2010. The declining state of nature also jeopardizes efforts to meet many of the United Nations's Sustainable Development Goals, such as ending hunger. "If we continue with business as usual, we'll miss [the goals]," Mace says. "We're quite good at making plans, and quite good at setting aside protected areas, but the response of the natural world is nothing like good enough to meet the targets."

The new report is the first global analysis of the state of nature since 2005, when researchers assembled what is known as the Millennium Ecosystem Assessment. But the hope is that the IPBES report will have a greater impact than that study. The new report "is significant, because it's the first global assessment that has been asked for by governments-they've been involved in it, they've shaped it," says Peter Bridgewater, a biodiversity policy expert and adjunct at the University of Canberra, who was not involved in the report. Delegates from member nations approved the report on Saturday, after a week negotiating the text of the 40-page summary for policymakers.

According to scenarios included in the report that examine the consequences of various possible policy decisions to 2050, the news will keep getting worse unless transformative change occurs. That change would involve undertaking a wide array of activities, the authors write, including land restoration, more widespread adoption of agroecological practices such as preventing soil erosion, and more widely enforced limits on fishing. Fundamentally, reversing the trends will require a shift to a more sustainable global economy, the authors state, and "steering away from the current limited paradigm of economic growth."

In its call for transformation, the report anticipates pushback: "By its very nature, transformative change can expect opposition from those with interests vested in the status quo, but such opposition can be overcome for the broader public good." IPBES will examine how to achieve such transformative change as part of its next round of work, notes Esther Turnhout, a science policy expert at Wageningen University in the Netherlands. The goal, she says, would be to better understand "how we can tackle those challenges and why we haven't done so."

Anne Larigauderie, executive secretary of IPBES, is optimistic the global report released today will make a difference. "The moment for biodiversity has arrived," she says, pointing to growing initiatives and interest in protecting nature. "There is so much evidence, and the scientific community is speaking with one voice," Larigauderie says. "Now it's not something that can be ignored."

doi:10.1126/science.aax9287

Erik is a reporter at Science, covering environmental issues and UK research.

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Landmark analysis documents the alarming global decline of nature

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The state of biodiversity and ecosystems is at its most perilous point in human history and the decline is accelerating, warns a landmark assessment released today. But the hope is that the bleak assessment-crafted by hundreds of scientists and historic in its depth and breadth-will finally persuade governments and others of the need to change course and prevent further harm to the ecological systems that provide for human well-being.

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To grow the world's wheat, corn, and beans, farmers need phosphorus-an essential nutrient that comes from bird and bat droppings and rock deposits. But the global supply of easily mineable phosphorus is dwindling; to stave off the coming drought, scientists are exploring an alternative: recycling animal manure for its phosphorus content. Now, they've come up with the world's first map of this underappreciated resource, which shows that most manure is exactly where farmers need it-in their own backyards.

To make their map (above), researchers used data on livestock density and calculated the annual amount of phosphorus excreted by cattle, pigs, chickens, sheep, and goats globally- as much as a whopping 130,000 kilograms per square kilometer, they report in an upcoming issue of Earth's Future. (Various estimates put total global production between 15 million to 20 million metric tons per year.) The researchers found "hot spots," areas in which manure-based phosphorus is a widely available, but underused, on every continent except Antarctica. Unsurprisingly, many of those hot spots are near farming communities and river deltas where agricultural runoff abounds.

But reusing old phosphorus is easier said than done. To process pig and cow poo, farmers must break it down with bacteria or use special equipment to crystallize its struvite-the same phosphate mineral that makes up some kidney and bladder stones. These processes are already used by many commercial farms, which together help recycle about half the global supply of manure. But they are costly for small family farms, which supply most food in parts of Asia, sub-Saharan Africa, and Latin America.

The researchers hope their map will encourage countries, including India, Brazil, China, and the United States (which together use 66% of the world's phosphorus fertilizer), to support phosphorus recycling. Not only would more recycling reduce imports, but it would also help the environment by eliminating manure-and its phosphorus-from the water supply. It could also put a few more years on our phosphorus clock.

doi:10.1126/science.aax9536

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This global map of manure could help save farming as we know it

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To grow the world's wheat, corn, and beans, farmers need phosphorus-an essential nutrient that comes from bird and bat droppings and rock deposits. But the global supply of easily mineable phosphorus is dwindling; to stave off the coming drought, scientists are exploring an alternative: recycling animal manure for its phosphorus content.

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A fossil site in North Dakota records a stunningly detailed picture of the devastation minutes after an asteroid slammed into Earth about 66 million years ago, a group of paleontologists argue in a paper due out this week. Geologists have theorized that the impact, near what is now the town of Chicxulub on Mexico's Yucatán Peninsula, played a role in the mass extinction at the end of the Cretaceous period, when all the dinosaurs (except birds) and much other life on Earth vanished.

If the team, led by Robert DePalma, a graduate student in paleontology at the University of Kansas in Lawrence, is correct, it has uncovered a record of apocalyptic destruction 3000 kilometers from Chicxulub. At the site, called Tanis, the researchers say they have discovered the chaotic debris left when tsunamilike waves surged up a river valley. Trapped in the debris is a jumbled mess of fossils, including freshwater sturgeon that apparently choked to death on glassy particles raining out of the sky from the fireball lofted by the impact.

"That's the first ever evidence of the interaction between life on the last day of the Cretaceous and the impact event," says team member Phillip Manning, a paleontologist at the University of Manchester in the United Kingdom. The deposit may also provide some of the strongest evidence yet that nonbird dinosaurs were still thriving on impact day.

"Outcrops like [this] are the reasons many of us are drawn to geology," says David Kring, a geologist at the Lunar and Planetary Institute in Houston, Texas, who wasn't a member of the research team. "Those few meters of rock record the wrath of the Chicxulub impact and the devastation it caused." But not everyone has fully embraced the find, perhaps in part because it was first announced to the world last week in an article in The New Yorker. The paper, in the Proceedings of the National Academy of Sciences ( PNAS), does not include all the scientific claims mentioned in The New Yorker story, including that numerous dinosaurs as well as fish were buried at the site.

"I hope this is all legit-I'm just not 100% convinced yet," says Thomas Tobin, a geologist at the University of Alabama in Tuscaloosa. Tobin says the PNAS paper is densely packed with detail from paleontology, sedimentology, geochemistry, and more. "No one is an expert on all of those subjects," he says, so it's going to take a few months for the research community to digest the findings and evaluate whether they support such extraordinary conclusions.

In the early 1980s, the discovery of a clay layer rich in iridium, an element found in meteorites, at the very end of the rock record of the Cretaceous at sites around the world led researchers to link an asteroid to the End Cretaceous mass extinction. A wealth of other evidence has persuaded most researchers that the impact played some role in the extinctions. But no one has found direct evidence of its lethal effects.

DePalma's team says the killing is captured in forensic detail in the 1.3-meter-thick Tanis deposit, which it says formed in just a few hours, beginning perhaps 13 minutes after impact. Although fish fossils are normally deposited horizontally, at Tanis, fish carcasses and tree trunks are preserved haphazardly, some in near vertical orientations, suggesting they were caught up in a large volume of mud and sand that was dumped nearly instantaneously. The mud and sand are dotted with glassy spherules-many caught in the gills of the fish-isotopically dated to 65.8 million years ago. They presumably formed from droplets of molten rock launched into the atmosphere at the impact site, which cooled and solidified as they plummeted back to Earth. A 2-centimeter-thick layer rich in telltale iridium caps the deposit.

Tanis at the time was located on a river that may have drained into the shallow sea covering much of what is now the eastern and southern United States. DePalma's team argues that as seismic waves from the distant impact reached Tanis minutes later, the shaking generated 10-meter waves that surged from the sea up the river valley, dumping sediment and both marine and freshwater organisms there. Such waves are called seiches: The 2011 Tohoku earthquake near Japan triggered 1.5-meter-tall seiches in Norwegian fjords 8000 kilometers away.

DePalma and his colleagues have been working at Tanis since 2012. "Robert has been meticulous, borderline archaeological in his excavation approach," says Manning, who has been working at Tanis from the beginning.

But others question DePalma's interpretations. "Capturing the event in that much detail is pretty remarkable," concedes Blair Schoene, a geologist at Princeton University, but he says the site does not definitively prove that the impact event was the exclusive trigger of the mass extinction. Schoene and some others believe environmental turmoil caused by large-scale volcanic activity in what is now central India may have taken a toll even before the impact.

Other geologists say they can't shake a sense of suspicion about DePalma himself, who, along with his Ph.D. work, is also a curator at the Palm Beach Museum of Natural History in Wellington, Florida. His reputation suffered when, in 2015, he and his colleagues described a new genus of dinosaur named Dakotaraptor, found in a site close to Tanis. Others later pointed out that the reconstructed skeleton includes a bone that really belonged to a turtle; DePalma and his colleagues issued a correction.

DePalma may also flout some norms of paleontology, according to The New Yorker, by retaining rights to control his specimens even after they have been incorporated into university and museum collections. He reportedly helps fund his fieldwork by selling replicas of his finds to private collectors. "His line between commercial and academic work is not as clean as it is for other people," says one geologist who asked not to be named. DePalma did not respond to an email request for an interview.

Manning points out that all fossils described in the PNAS paper have been deposited in recognized collections and are available for other researchers to study. "It saddens me that folks are so quick to knock a study," he says. "That some competitors have cast Robert in a negative light is unfortunate and unfair," says another co-author, Mark Richards, a geophysicist at the University of California, Berkeley.

Manning confirms rumors that the study was initially submitted to a journal with a higher impact factor before it was accepted at PNAS. He says the reviewers for the higher-profile journal made requests that were unreasonable for a paper that simply outlines the discovery and initial analysis of Tanis. "After a while, we decided it wasn't a good route to go down," he says. The paper cleared peer review at PNAS within about 4 months.

Several more papers on Tanis are now in preparation, Manning says, and he expects they will describe the dinosaur fossils that are mentioned in The New Yorker article. Its author, Douglas Preston, who learned of the find from DePalma in 2013, writes that DePalma's team found dinosaur bones caught up in the 1.3-meter-thick deposit, some so high in the sequence that DePalma suspects the carcasses were floating in the roiling water. Such a conclusion might provide the best evidence yet that at least some dinosaurs were alive to witness the asteroid impact. But just one dinosaur bone is discussed in the PNAS study-and it is mentioned in a supplement document rather than in the paper itself. That "disconnect" bothers Steve Brusatte, a paleontologist at the University of Edinburgh. "I just hope this hasn't been oversensationalized."

Until a few years ago, some researchers had suspected the last dinosaurs vanished thousands of years before the catastrophe. If Tanis is all it is claimed to be, that debate-and many others about this momentous day in Earth's history-may be over.

doi:10.1126/science.aax5400

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Astonishment, skepticism greet fossils claimed to record dinosaur-killing asteroid impact

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A fossil site in North Dakota records a stunningly detailed picture of the devastation minutes after an asteroid slammed into Earth about 66 million years ago, a group of paleontologists argue in a paper due out this week.

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A number of tiny, bat-winged dinosaurs flew the Jurassic skies, according to the strongest evidence yet for such creatures-a well-preserved fossil of a starling-size fluffball that may have looked a little like a flying squirrel. The find, recovered near a farming village in northeastern China, suggests dinosaurs were experimenting with several methods of flight during this period, but many were an evolutionary dead end.

"This fossil seals the deal-there really were bat-winged dinosaurs," says Stephen Brusatte, a paleontologist at the University of Edinburgh who was not involved with the study.

Scientists were already confident that a number of dinosaurs could fly. There are birds, of course, which are technically dinosaurs and appeared during the Jurassic period, at least 150 million years ago. Other dinosaurs sported feathers on their hind- and forelimbs, effectively giving them four birdlike wings.

Then, in 2015, researchers discovered a dinosaur that may have flown more like a bat. Named Yi qi (Mandarin for "strange wing") and discovered in northwestern China, the crow-size creature appeared to have a flap of skin stretched between its body and arm bones that was supported by a rod of cartilage. But the fossil, which belongs to an enigmatic group of dinosaurs called the scansoriopterygids, was partial and poorly preserved, so scientists couldn't be sure it actually flew like a bat. "There's been debate about whether the skin flap was really an airfoil or used for another purpose," Brusatte says.

The new fossil, named Ambopteryx longibrachium (meaning "both-wing" and "long arm," referring to this second method of dinosaur flight) and dated to about 163 million years ago during the Jurassic period, doesn't have that problem. Nearly every part of the little dino-which was uncovered by a farmer who provides the fossils he finds to the Chinese Academy of Sciences's Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing-is well-preserved, including membranous batlike wings similar to those of Yi qi. "You could have fit it in your hand," says IVPP paleontologist and study author Jingmai O'Connor. "It would have been this tiny, bizarre-looking, buck-toothed thing like nothing alive today."

Even Ambopteryx 's stomach contents were preserved. Researchers recovered pieces of bone and small rocks called gastroliths, which modern birds use to grind plant material, indicating the species may have been omnivorous. Though the creature was replete with feathers, these were a downy fuzz and not used for flight. O'Connor also speculates that males of the species may have sported long ornamental tail feathers, possibly to woo females, as can be seen in other scansoriopterygid fossils.

The complete skeleton has allowed scientists to make the first detailed analysis of differences in wing design and mode of flight between these dinosaurs and birds. Researchers measured the bones of the arms and fingers in each type of wing and compared them using statistical methods.

Ambopteryx's wings were formed by elongating the humerus and ulna, the bones of the upper and lower arm in humans, the team reports today in Nature. Birds instead achieved flight by elongating their metacarpals, analogous to our fingers. "The main lift-generating surface of birds' wings is formed by feathers," O'Connor explains. "In bats, pterosaurs [dinosaur-era reptiles that flew similar to bats], and now scansoriopterygids-you instead have flaps of skin that are stretched out in between skeletal elements."

"This new discovery shows Yi qi was not an aberrant species, but that there was an entire group of bat dinosaurs taking to the skies in the [Jurassic]," says Darla Zelenitsky, a paleontologist at the University of Calgary in Canada who has studied feathered dinosaurs.

However, although nearly 10,000 species of birds live today, no scansoriopterygids survived past the end of the Jurassic. That suggests their early experiment in flight was far less successful, O'Connor says. Still, she says, their existence is remarkable, given that flight has only evolved in a handful of groups of animals across the entire history of life. "The idea that flight evolved more than once in dinosaurs is incredibly exciting and hasn't quite sunk into the scientific community yet."

"The evolution of flight wasn't a gradual march from dinosaur to bird," Brusatte adds. "It involved lots of experimentation and tinkering."

doi:10.1126/science.aax9708

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New batlike dinosaur was early experiment in flight

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A number of tiny, bat-winged dinosaurs flew the Jurassic skies, according to the strongest evidence yet for such creatures-a well-preserved fossil of a starling-size fluffball that may have looked a little like a flying squirrel. The find, recovered near a farming village in northeastern China, suggests dinosaurs were experimenting with several methods of flight during this period, but many were an evolutionary dead end.

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About two-thirds of the world's longest rivers are no longer free flowing, compromising their ability to move sediment, facilitate fish migration, and perform other vital ecosystem services, according to a new study. And with more than 3700 large dams in the works, the future of free-flowing waterways looks even bleaker, researchers say.

To get a global perspective on river conditions, Bernhard Lehner, a hydrologist at McGill University in Montreal, Canada, who for years has studied the effects of dams on entire watersheds, teamed up with researchers from the World Wildlife Fund (WWF), based in Washington, D.C., and elsewhere. Using aerial, satellite, and other data, the team examined 12 million kilometers of waterways, evaluating their flows in 4.5-kilometer segments.

Traditionally, researchers focused on dams when assessing a river's free flow. But in this assessment, the team also considered the impacts on flow created by riverbank levees, other flood control structures, and water diversions for power, irrigation, or drinking supplies. "It's a more comprehensive analysis of global hydrology than we have had before," says N. LeRoy Poff, a hydroecologist at Colorado State University in Fort Collins who was not part of the project.

In particular, the researchers focused on the 246 longest rivers encompassing more than 1000 kilometers of flowing water-think the Nile and Mississippi rivers-because of their huge ecological impact. Just 90 of those big rivers are still unencumbered, they report today in Nature. Most of the remaining unblocked rivers are in the Amazon, the Arctic, and Africa's Congo basin.

"In the U.S., Europe, and more developed areas, these longer, free-flowing rivers don't really exist," Poff says. And those free rivers that remain "are some of the most important places for freshwater species," says Michele Thieme, a WWF freshwater ecologist. Freshwater plants and animals are declining twice as fast as terrestrial and marine populations, WWF has found. And rivers in general have a lot of hidden value not fully appreciated by policymakers, Thieme notes.

Thieme and Bernhard hope this assessment will have an effect on both global and local policymaking. It provides a ready source of data for countries working to meet international sustainable management goals, which include protection for freshwater systems. And the study's methodology can be applied more locally with finer scale data to help guide where to site-or remove-dams to maintain or restore free flows.

WWF, for example, is advocating increased use of solar or wind power to cut down on the need for more hydroelectric dams, which could help protect areas such as Asia's Mekong delta. The group has also worked with Myanmar and the World Bank's International Finance Corporation to try to keep dams off the Irrawaddy and the Salween river, two of that country's major free-flowing waterways. And it's helping establish baseline monitoring of the water quality of Canada's Liard River, which runs from the Yukon into the Northwest Territories and is one of that country's last long free-flowing rivers.

Already, the increased awareness of the value of free-flowing rivers is leading to policy changes, WWF notes. In February, Slovenia agreed to stop hydropower development on that country's Mura River, one of the last refuges with otters and the Danube salmon. Last year, Mexico established water reserves in about 300 river basins-water reserved for nature and not stored behind dams.

Bernhard would like to see more such decisions. "We hope that our data can be used to find smarter and more sustainable solutions in how we manage rivers," he says.

doi:10.1126/science.aax9703

Liz is a senior correspondent covering many aspects of biology for Science.

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Two-thirds of the world's longest rivers no longer run free

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About two-thirds of the world's longest rivers are no longer free flowing, compromising their ability to move sediment, facilitate fish migration, and perform other vital ecosystem services, according to a new study. And with more than 3700 large dams in the works, the future of free-flowing waterways looks even bleaker, researchers say.

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New Study Reveals Dark Side of Outdoor Night Lighting

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Global night light is getting bigger and brighter, blotting out the stars of the Milky Way for one-third of humankind, according to a new study of federal satellite data measuring outdoor lighting.

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About One Million Species Face Risk of Extinction, U.N. Report Says

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The rate that species are going extinct is accelerating to unprecedented levels, with about one million plant and animal species now at risk of dying out over the next few decades, according to new findings from a U.N. group.

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On June 23, 1988-a blisteringly hot day in Washington, D.C.-James Hansen told a Senate committee that "the greenhouse effect has been detected and is changing our climate now." At the time, Hansen was the head of NASA's Goddard Institute for Space Studies, and though his testimony was certainly not the first official warning about the "greenhouse effect"-a report to President Lyndon Johnson, in 1965, predicted "measurable and perhaps marked changes in climate" in the decades to follow-it was the first to receive national news coverage. The Times ran the story at the top of the front page, with a graph showing a long-term rise in average global temperatures.

This week marks the thirtieth anniversary of Hansen's testimony, and it would be hard to think of a more lugubrious milestone. In the intervening three decades, nearly half of the Arctic ice cap has melted away, the oceans have acidified, much of the American West has burned, lower Manhattan, South Florida, Houston, and New Orleans have flooded, and average temperatures have continued to climb. Just last week, a team of scientists reported in Nature that the rate of melt off Antarctica has tripled in the past decade; as the Washington Post put it, "If that continues, we are in serious trouble." (Were the Antarctic ice to melt away entirely, global sea levels would rise by two hundred feet; if just the more vulnerable West Antarctic Ice Sheet melted, sea levels would rise by about ten feet.) Also last week, scientists reported that most of Africa's oldest baobab trees have died, probably because of climate change, and last month researchers showed that rising CO 2 levels were reducing the nutrient content of rice, which is probably the single most important food source for people. Yet Washington continues to ignore the problem, or, worse still, to actively impede efforts to address it. How can this be?

A possible answer, which seems to be the one that Hansen himself, at least in part, subscribes to, is that scientists are to blame. Hansen is now seventy-seven and retired from NASA. He recently told the Associated Press that he regrets not being "able to make this story clear enough for the public." Many climate scientists seem similarly to believe that they are not good at conveying information to lay audiences, and, as a result, dozens of Web sites and several whole organizations have been created to help them communicate better.

As someone who has interviewed a lot of climate scientists-including, on several occasions, Hansen-I can attest that, as a group, they are not particularly good at expressing themselves. (I once wrote a Profile of Hansen, and watched him lose even audiences predisposed to adore him.) But thirty years into the so-called climate debate-fifty-three years, if you go back to the report to L.B.J.-I also think it's time to put this particular story line to rest.

Back in 1988, just about the only information available on climate change was written in the dry-as-standard-deviations style of academic science. The following year, Bill McKibben published the first book on the subject aimed at a popular audience, " The End of Nature." Since then, more generally accessible books have been written on the climate than even the most avid reader could possibly keep up with; these include kids' books, comic books, and even a coloring book. Meanwhile, countless newspaper and magazine articles, television specials, and documentaries have appeared on the topic. Above all, climate change has become obvious. You don't need to read or watch or hear about it; in many parts of the world, all you have to do is look around. The southwestern United States, for instance, is currently experiencing such a severe drought that water restrictions are in place and many national forests are closed. "Thirty years ago, we may have seen this coming as a train in the distance," Deke Arndt, the chief of climate monitoring at the National Oceanic and Atmospheric Administration center in Asheville, North Carolina, recently told the A.P. "The train is in our living room now."

Instead of using this anniversary to lament the failures of climate scientists, I'd like to propose that we use it to celebrate-well, "celebrate" probably isn't quite the right word, but maybe recognize-their successes. Three decades ago, led by Hansen, they made a series of predictions; for the most part these have proved to be spectacularly accurate. That we, the general public, have failed to act on these predictions says a lot more about us than it does about them.

I happened to interview Hansen last year, for a video project. I asked him if he had a message for young people. "The simple thing is, I'm sorry we're leaving such a fucking mess," he said. Could the message be any clearer than that?

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Listening to James Hansen on Climate Change, Thirty Years Ago and Now

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On June 23, 1988-a blisteringly hot day in Washington, D.C.-James Hansen told a Senate committee that "the greenhouse effect has been detected and is changing our climate now."

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Last week, representatives from around the world gathered to begin another round of climate negotiations in Katowice, a city in the heart of Poland's coal-mining country. Delegates arriving at the meeting, known in United Nations-speak as a Conference of the Parties, or COP, were treated to an outdoor performance by a Polish coal miners' band. Inside the convention pavilions, they found mounds of coal displayed behind glass, like objets d'art, as well as arrangements of coal-based cosmetics and coal-encrusted jewelry. Poland gets about eighty per cent of its electricity from coal, the most carbon-intensive of carbon-based fuels, and the Polish President, Andrzej Duda, noted in his opening remarks that the country had enough as yet unmined supplies to last another two centuries. "It would be hard not to use them," he said.

Depending on how you look at things, a coal-stuffed climate summit is either completely absurd-"beyond parody," as one commentator put it-or merely appropriate. With each passing month, the threat posed by global warming grows clearer. And so, too, does the world's failure to take that threat seriously. "We are in trouble," the United Nations' Secretary-General, António Guterres, said at the COP 's opening session. "It is hard to comprehend why we are collectively still moving too slowly-and even in the wrong direction."

In October, a report from an international team of scientists warned that the planet was closer to dangerous warming than had previously been believed, and that a critical threshold could be crossed within a matter of years. To avoid this, a rapid and total overhaul of global energy systems would be needed. Such a transformation, the team observed, has "no documented historical precedent."

Then, in November, a study put together by experts from thirteen U.S. federal agencies laid out the extent to which warming is already wreaking havoc in this country-via drought, intensifying storms, and an increasing number of wildfires. The study predicted that, as temperatures continue to rise, the country will experience "losses to infrastructure and property" that could run to hundreds of billions of dollars annually. (The Trump Administration did not tamper with the contents of the study, a version of which must, by law, be presented every four years. Instead, it sought to bury the assessment, by releasing it the day after Thanksgiving.) In the brief interval between the publication of the two reports, the deadliest wildfire in California's history, the Camp Fire, claimed the lives of at least eighty-five people.

As these alarms were going off, one nation after another reached for the snooze button. Last month, the President-elect of Brazil, Jair Bolsonaro, chose as his Foreign Minister a climate-change denier, Ernesto Araújo. (Araújo has described climate science as part of a plot by "cultural Marxists" to cripple Western economies.) The incoming government promptly announced that Brazil was reneging on its offer to host the next COP, which is scheduled for November, 2019.

Last week, just as the session in Katowice was getting under way, the French President, Emmanuel Macron, suspended plans to raise that nation's gasoline and diesel-fuel taxes. The increase had been intended to speed the transition to cleaner cars; the postponement came in response to violent protests by the so-called "yellow vest" movement. Demonstrators complained that Macron was worried about the end of the world, while they were worried about the end of the month.

The Trump Administration, meanwhile, has already made plain its intention of undermining the whole COP process. Last week, the Administration basically flipped off negotiators in Poland by unveiling not one but two new schemes for promoting fossil-fuel use. The first was a proposed rollback of an Obama-era rule that effectively blocked new construction of coal-fired power plants. (The rollback was presented by the acting head of the Environmental Protection Agency, Andrew Wheeler, a former coal-industry lobbyist.) The second was a plan to open some nine million acres of public lands in Western states to oil and gas drilling by sweeping aside protections for the greater sage grouse. Environmentalists-justifiably-labelled this move a "giveaway" to the fossil-fuel industry. As the Times noted, it would "open more land to drilling than any other step the administration has taken."

This year's COP-the twenty-fourth in the series-is supposed to resolve procedural questions left hanging when the Paris Agreement was negotiated, three years ago, at COP 21. Under the agreement, each country was asked to formulate its own emission-reduction plan. The aim of this give-what-you-can approach was to nudge developed and developing countries toward a consensus. It was hoped that nations would, over time, push one another to increase their commitments. Back in 2015, this might have been a reasonable expectation. Now, in the era of America First, it looks increasingly like wishful thinking.

On Wednesday, even as negotiators in Poland were debating how to monitor CO 2 reductions, researchers at the University of East Anglia and a group called the Global Carbon Project announced that emissions are again on the rise. Worldwide, they are expected to have increased by almost three per cent in 2018, to more than forty billion tons. In the United States, emissions rose by about 2.5 per cent, following a decade of decline. The message from this year's tally "is more brutal than ever," David Reay, a climate scientist at the University of Edinburgh, told the Guardian. "We are deep in the red and heading still deeper."

Even gloomier was the assessment of a trio of prominent researchers at universities in California and Texas, which appeared last week in Nature. They argued that, while the latest warnings have been dire, they have not been dire enough. Owing in part to the recent uptick in emissions, warming will be "faster and more furious" than predicted. "For decades scientists and policymakers have framed the climate-policy debate in a simple way: scientists analyse long-term goals, and policymakers pretend to honour them," they wrote. "Those days are over."

If they're right, this year's carbon-friendly COP may indeed mark a turning point-the moment when climate negotiations can no longer be considered even a useful fiction. ♦

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Coal for Christmas at the U.N. Climate Conference

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Last week, representatives from around the world gathered to begin another round of climate negotiations in Katowice, a city in the heart of Poland's coal-mining country. Delegates arriving at the meeting, known in United Nations-speak as a Conference of the Parties, or COP, were treated to an outdoor performance by a Polish coal miners' band.

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The state loses a football field's worth of land every hour and a half. Now engineers are in a race to prevent it from sinking into oblivion.

The New Orleans Lakefront Airport was built by the Louisiana governor Huey P. Long on a tongue of fill that sticks out into Lake Pontchartrain. Its terminal was designed by the same architect Long had used to build a new Louisiana state capitol and a new governor's mansion, and it was originally named for one of Long's cronies, Abraham Shushan. Within eighteen months of the airport's opening, in 1934, Shushan had been indicted for money laundering and Long had been murdered. A few years later, the architect, too, went to prison.

Today, Lakefront Airport is used for small planes, which is how I recently found myself there, aboard a four-seat Piper Warrior. The Piper's pilot and owner was a lawyer who liked having an excuse to fly. The plane took off to the north, over Lake Pontchartrain, and looped back toward New Orleans. We picked up the Mississippi at English Turn, the sharp bend that brings the river almost full circle. Then we continued to follow the water as it wound its way into Plaquemines Parish.

Plaquemines is where the river meets the sea. On maps, it appears as a thick, muscular arm stretching into the Gulf of Mexico, with the Mississippi running, like a ropy blue vein, down the center. At the very end of the arm, the main channel divides into three, an arrangement that calls to mind fingers or claws, hence the area's name-the Bird's Foot.

Seen from the air, the parish has a very different look. If it's an arm, it's a horribly emaciated one. For most of its length-more than sixty miles-it's practically all vein. What little solid land there is clings to the river in two skinny strips.

Flying at an altitude of two thousand feet, I could make out the houses and farms and refineries that fill the strips, though not the people who live or work in them. Beyond was open water or patchy marsh. In many spots, the patches were crisscrossed with channels. Presumably, these had been dug when the land was firmer, to get at the oil underneath. In some places, I could see the outlines of what were once fields and are now rectilinear lakes. Great white clouds, billowing above the plane, were mirrored in the black pools below.

Plaquemines has the distinction-a dubious one, at best-of being among the fastest-disappearing places on Earth. Everyone who lives in the parish-and fewer and fewer people do-can point to some stretch of water that used to have a house or a hunting camp on it. This is true even of teen-agers. A few years ago, the National Oceanic and Atmospheric Administration officially retired thirty-one Plaquemines place-names, including Bay Jacquin and Dry Cypress Bayou, because there was no there there anymore.

And what's happening to Plaquemines is happening all along the coast. Since the days of Huey Long, Louisiana has shrunk by more than two thousand square miles. If Delaware or Rhode Island had lost that much territory, the U.S. would have only forty-nine states. Every hour and a half, Louisiana sheds another football field's worth of land. Every few minutes, it drops a tennis court's worth. On maps, the state may still resemble a boot. Really, though, the bottom of the boot is in tatters, missing not just a sole but also its heel and a good part of its instep.

A variety of factors are driving the "land-loss crisis," as it's come to be called. But the essential one is a marvel of engineering. Thousands of miles of levees, flood walls, and revetments have been erected to manage the Mississippi. As the Army Corps of Engineers once boasted, "We harnessed it, straightened it, regularized it, shackled it." This vast system, built to keep southern Louisiana dry, is the very reason the region is disintegrating, coming apart like an old shoe.

But if control is the problem it must also, by the logic of the Anthropocene, be the solution. And so a huge new public-works project is getting under way-this one aimed not at flood control so much as at controlled flooding. Ten pharaonic structures are planned. The furthest along of these is slated for Plaquemines Parish. It will feature enough concrete and riprap to pave Greenwich Village and, when operating at full capacity, will, by flow, be the twelfth-largest river in the country.

In one form or another, the Mississippi has been winding its way to the Gulf for millions of years. All the while, it has been carrying on its broad back vast loads of sediment-at the time of the Louisiana Purchase, some four hundred million tons annually. "I do not know much about gods; but I think that the river is a strong brown god," T. S. Eliot wrote. Whenever it overtopped its banks-something it used to do virtually every spring-the river cast its sediment across the plain. Season after season, layer after layer, clay and sand and silt built up. In this way, the "strong brown god" assembled the Louisiana Gulf Coast out of bits and pieces of Illinois and Iowa and Minnesota and Missouri and Arkansas and Kentucky.

Because the Mississippi is always dropping sediment, it is always on the move, seeking new and faster routes to the sea. Its most dramatic leaps are called avulsions. In the last seven thousand years, the river has avulsed six times, and each time it has set about laying down a new bulge of land. Lafourche Parish is what's left of the lobe laid down during the reign of Charlemagne. Western Terrebonne Parish is the remains of a delta lobe built during the time of the Phoenicians. The city of New Orleans sits on a lobe-the St. Bernard-created around the time of the pyramids. Many still more ancient lobes are now submerged.

The Mississippi's most recent lobe is the Plaquemines-Balize Delta, otherwise known as Plaquemines Parish. It started to build about fifteen hundred years ago, after the river's last great leap. The next avulsion is now overdue. Only human invention, in the form of steel and concrete, stands in its way.

Meanwhile, as the Mississippi has pushed lobe after lobe into the sea, the sea has pushed back. The delta's soft, jello-like soils tend to de-water and compact over time, with the newest layers, which are wetter, losing bulk most rapidly. Where the river delivers enough sand and clay to make up for the lost volume, the land holds its own. Where compaction outpaces accretion, the land begins to subside until, eventually, the Gulf reclaims it. In southern Louisiana, to borrow from Bob Dylan, any place that is "not busy being born is busy dying."

Such a mutable landscape is a hard one to settle. Nevertheless, Native Americans were probably living in the delta even as it was being created. Their strategy for dealing with the river's vagaries, as far as archeologists have been able to determine, was one of accommodation. If the Mississippi flooded, they sought higher ground. If it shifted quarters, they did, too.

When the French arrived, they consulted with the tribes living there. In the winter of 1700, the colonists erected a wooden fort on what's now the east bank of Plaquemines. Pierre Le Moyne d'Iberville, the fort's commander, had been assured by a Bayogoula guide that the fort's site was a dry one. Whether this represented a purposeful misstatement or just a misunderstanding, "dry" in southern Louisiana being a relative term, the place soon flooded out. A priest who visited the following winter found soldiers wading "mid-leg deep" to get to their cabins. In 1707, the fort was abandoned. "I do not see how settlers can be placed on this river," Iberville's brother Jean-Baptiste Le Moyne de Bienville wrote to the authorities in Paris, explaining the retreat.

Bienville went on to found New Orleans, in 1718, in spite of his cold, wet feet. The new city, called, in honor of its watery surroundings, L'Isle de la Nouvelle Orléans, was laid out where the land was highest. Counterintuitively, this was right up against the Mississippi. During floods, sand and other heavy particles tend to settle out of the water first, creating what are known as natural levees. ( Levée, in French, simply means "raised.")

One year after its founding, L'Isle de la Nouvelle Orléans suffered its first flood. "The site is drowned under half a foot of water," Bienville wrote. The settlement remained submerged for six months. Rather than retreat again, the French dug in. They started cutting drainage channels through the muck and raising artificial barriers atop the natural ones. Most of this backbreaking labor was performed by African slaves. By the seventeen-thirties, slave-built levees stretched along both banks of the river for nearly fifty miles.

These early levees, made of earth reinforced with timber, failed frequently. But they established a pattern that endures to the present day. Since the city wasn't going to move to suit the river, the river would be forced to stay put. With each failure, the levees were improved-built higher and wider and longer. By the War of 1812, they ran along the river for more than a hundred and fifty miles.

A few days after I flew over Plaquemines, I found myself once again gazing down on the parish. The Mississippi was rising rapidly, and there was concern that the gates on a spillway upriver from New Orleans weren't functioning. If the water kept rising and the spillway failed to open, the city and the parishes downriver from it would be inundated. I was with several engineers, and they were starting to get nervous. I was anxious, too, though only a little, since the Mississippi we were looking at was about five inches wide.

The Center for River Studies is an outpost of Louisiana State University. It's situated not far from the actual Mississippi, in Baton Rouge, in a building that resembles a hockey rink.

At the Center's center is a 1:6,000 replica of the delta, from the town of Donaldsonville, in Ascension Parish, to the tip of the Bird's Foot. The model is made of high-density foam that's been machined to mimic the region's topography and all that's been added to it-the levees, the gates, the flood walls. The size of two basketball courts, it's sturdy enough to stand on. But when the model is running, as it was the day I showed up, it's hard to take more than a few steps. There are large puddles representing Lake Pontchartrain and Lake Borgne, which are not really lakes but, rather, brackish lagoons. More puddles represent Barataria Bay and Breton Sound, inlets of the Gulf, and still more puddles represent various bayous and backwaters. I pulled off my shoes and tried to walk from New Orleans to the Gulf. By the time I got to English Turn, my feet were wet. I stuffed my soggy socks into my pocket.

The model delta, which represents a kind of relief map of the future, is supposed to simulate flooding and sea-level rise and to help test strategies for dealing with them. Prominently displayed on one of the walls of the Center is a quote attributed to Albert Einstein: "We cannot solve our problems with the same thinking we used when we created them."

At the time of my visit, the model was so new that it was still being calibrated. This involved running simulations of well-studied disasters from the past, like the flood of 2011. In the spring of that year, heavy snowmelt combined with weeks of intense rain across the Midwest, resulting in record-breaking water levels. To spare New Orleans, the Army Corps of Engineers opened the Bonnet Carré Spillway, about thirty miles upriver from the city. (The Bonnet Carré diverts water into Lake Pontchartrain; when all the gates are open, the flow through it exceeds that of Niagara Falls.) On the model, the spillway gates were represented by small strips of brass attached to copper wires. Because they hadn't worked properly in previous trials, an engineer was watching over them from a folding chair. He looked like a latter-day Gulliver, bent over a drowning Lilliput. He, too, I noticed, had wet socks.

In the world of the model, time-as well as space-contracts. On its accelerated schedule, a year passes in an hour, a month in five minutes. As I watched the weeks race by, the river kept rising. Much to the engineers' relief, this time the gates on the pint-size Bonnet Carré opened. Water began flowing out of the Mississippi into Lake Pontchartrain, and New Orleans was saved, at least for now.

Two separate vats served as the source for the mini-Mississippi. One provided clear water. The other held the mud of the Little Muddy, though not real mud. This was simulated sediment, imported from France and composed of exactingly milled plastic pellets-teensy, half-millimetre-wide pellets for large grains of sand and even teensier ones to represent finer particles. The sediment was jet black and stood out against the foam riverbed and surrounding terrain, which were painted bright white.

During the mock flood, some of the dark pellets had been flushed down the spillway, into Lake Pontchartrain. Others had settled in the riverbed, where they'd formed miniature shoals and sandbars. Most had swooshed out past New Orleans and around English Turn. So thick with simulated sediment were the channels of the Bird's Foot that they looked as if they were filled with ink. This inky mix was streaming in dark eddies toward the Gulf of Mexico, where, had it been real sediment, it would have vanished off the coast.

Here, in black and white, was Louisiana's land-loss dilemma. Had the river been left to its own devices, a super-wet spring like that of 2011 would have sent the Mississippi and its distributaries surging over their banks. The floodwaters would have wreaked havoc, but they would have spread tens of millions of tons of sand and clay across thousands of square miles of countryside. The new sediment would have formed a fresh layer of soil and, in this way, countered subsidence.

Thanks to the intervention of the engineers, there had been no spillover, no havoc, and hence no land-building. The future of southern Louisiana had, instead, washed out to sea.

Directly next door to the Center for River Studies sits the headquarters of Louisiana's Coastal Protection and Restoration Authority. C.P.R.A. was founded in 2005, a few months after Hurricane Katrina hit, inundating New Orleans and leaving more than fifteen hundred Louisianans dead. (The storm claimed an additional three hundred lives in other states.) The authority's official mission is to implement "projects relative to the protection, conservation, enhancement and restoration of the coastal area of the state," which is a nice way of saying that it's supposed to prevent the region from disappearing.

One day while I was in Baton Rouge, I met up with two C.P.R.A. engineers at the model. As we chatted, someone flipped a switch controlling projectors in the ceiling. Suddenly, the fields of Plaquemines turned green and the Gulf blue. A satellite image of New Orleans glowed in the crook between the Mississippi and Lake Pontchartrain. The effect was dazzling, if also a little unnerving, as when Dorothy steps out of sepia-toned Kansas into Oz.

"You can see there's not a lot of land in Plaquemines," Rudy Simoneaux, one of the engineers, observed. He was wearing a shirt embroidered with the C.P.R.A. emblem, a circle with marsh grass on one side, waves on the other, and a black flood wall in between. "It's kind of frightening when you look at this model and realize how close we all are to water."

Simoneaux and his colleague, Brad Barth, were holding a public meeting that evening in Plaquemines, so, after we'd admired the mini-Mississippi for a while, we set out for the real thing. Our destination was Buras, a town ten miles north of the Bird's Foot. We reached the parish seat, Belle Chasse, in time to grab po'boys for lunch, then continued south on State Route 23, the only through road on the parish's west bank.

Much of Plaquemines lies below sea level-six feet under, people sometimes say. This arrangement is made possible by four sets of levees. Two run along the river, one on each bank. Another two-known as "back levees"-run between the parish and the Gulf, to stop the sea from rolling in. The levees, which keep water out, also keep water in. When they are breached or overtopped, Plaquemines fills up like a pair of long, skinny bathtubs.

Plaquemines was devastated by Katrina, which made landfall in Buras, and then was ravaged again, just a few weeks later, by Hurricane Rita, the most intense storm ever recorded over the Gulf. For months after these back-to-back disasters, Route 23 was blocked by washed-up fishing boats. Dead cows hung from the trees. In anticipation of the next catastrophe, public buildings in the parish stand on improbable pilings. Where other schools might have a gym or a ground-floor cafeteria, South Plaquemines High has enough empty space to park a fleet of tractor trailers. (The school's mascot is a swirling hurricane.) Many of the homes in the parish have been similarly elevated. One house we passed had been raised to a particularly vertiginous height; Simoneaux estimated that its pilings were thirty feet tall.

"That's really getting up there," he said. We were driving alongside the river but inside the levees, so for long stretches the Mississippi was invisible. Every so often, ships would loom into view. From the vantage point of the road, they appeared to be floating not on water but on air, like zeppelins.

Near the town of Ironton, Simoneaux pulled off Route 23 onto a gravel drive. At the end of it, we climbed over some barbed wire onto a scruffy field. It was a steamy day, and the field, dotted with puddles, smelled of rot. Flies buzzed lazily in the thick afternoon air.

The land we were standing on was a project technically known as BA-39. Simoneaux explained that, like the rest of the delta, BA-39 had come out of the Mississippi, though not quite in the usual way. "Picture a massive, eight-foot drill bit on the bottom of the river," he said. As the drill spun, it had gouged out sand and mud. Enormous diesel-powered pumps had sent this slurry gushing through a thirty-inch steel pipe. The pipe had run for five miles, from the west bank of the Mississippi, over the river levees, under Route 23, across some cattle fields, over the back levees, and finally into a shallow basin of Barataria Bay. There, the muck had piled up until bulldozers spread it around.

BA-39 had proved, not that further proof was really necessary, what enough pipes and pumps and diesel fuel can accomplish. Nearly a million cubic yards of sediment had made the five-mile journey, resulting in the creation-or, to be more accurate, the re-creation-of a hundred and eighty-six paludal acres. Here were all the benefits of flooding without the messy side effects: drowned citrus groves, drowned people, cows hanging from the trees. "We took centuries of land-building and we did it in a year," Simoneaux observed. The bill for the project had been six million dollars, which, I calculated, meant that the acre we were standing on had cost about thirty thousand dollars.

C.P.R.A.'s somewhat redundantly titled "comprehensive master plan" calls for dozens more such "marsh creation" projects, each with a price tag of millions or, in some cases, tens of millions of dollars. But Louisiana is locked in a race with the Red Queen, and in this race it has to move twice as fast just to stay even. To match the pace of land loss, the state would have to churn out a hundred and eighty-six acres every nine days. Meanwhile, the artificial marsh had already begun to de-water and subside. According to the authority's projections, in another decade, BA-39 will once again have sunk away.

We reached Buras at around three o'clock and turned in at a sign advertising "Cajun Fishing Adventures." The sign showed ducks and fish leaping into the air as if startled by some kind of explosion. Behind a grove of palms was an A-frame lodge with a pool out back.

The lodge's owner was a fish-and-game guide named Ryan Lambert. "I want to teach people not to listen to propaganda," he said, explaining why he'd volunteered his lodge for the evening's meeting. "I want them to see for themselves." To this end, he'd also organized a flotilla of boats to take attendees out on the Mississippi. I joined a group that included a reporter from the local Fox station and Lambert's big black dog.

On the water, it was about ten degrees cooler than onshore. A stiff breeze set the dog's ears flapping like flags. We hit the wake of another boat, and the Fox reporter, trying to balance a camera on his shoulder, almost fell overboard.

Unlike on Plaquemines' west bank, where the levees stretch all the way to the Bird's Foot, on the east bank they give out right about at the point where, if the parish were actually an arm, its elbow would go. South of the elbow, the river regularly overflows. On occasion, it cuts a new channel, sending water and sediment flowing in new directions and, in the process, creating land.

"Everything you see in front of you used to be open water," Lambert said, as we glided past a wide stretch of green. "Now it's lush and beautiful." His mirrored sunglasses reflected the low, late-afternoon sun and the tea-colored river.

"Look at all the new willow trees!" he exclaimed. He was steering with one hand and gesturing with the other. "Look at the birdlife!" The Fox reporter asked what the spot was called.

"It's hard to put a name on it, because it doesn't have a name, because it's new," Lambert said. "This is the newest land in the world!"

We sped in and out of unnamed bayous. A large alligator sunning itself on a log plopped into the water as we passed. "Isn't this beautiful?" Lambert kept saying. "When I come here, I feel great. When I go over to the west bank, I want to vomit." The newborn marsh had the sweet smell of freshly cut grass. Way off in the distance, I could see the silhouette of a giant oil platform, perched above the Gulf.

Back on the west bank, the lodge was filling up. A screen had been set up in a large room decorated with an elk's head, a stuffed squirrel, and several fish mounted in arcing poses. About fifty people had gathered, some sitting on couches, others leaning against the walls beneath the fish and the elk.

Barth began with a slide presentation. He explained the deep geology-how the coast had built up over the millennia, delta lobe by delta lobe, as the Mississippi thrashed around. Then he laid out the problem: How were two million people going to live in a region that was sinking into oblivion?

"We're in an uphill battle against sea-level rise and subsidence," Barth said. C.P.R.A. would continue to pump and lay pipe. "We will attempt to dredge every ounce of sediment out of the river that we can," he promised. But projects like BA-39 were incommensurate with the scale of the problem: "We need to be bold."

When the Mississippi bursts through its levees, be they natural or man-made, the opening is called a crevasse. For anyone standing in the way, a crevasse signifies disaster, and for much of New Orleans's history such disasters were commonplace. (Donald W. Davis, a geographer at L.S.U., has dubbed the first centuries of the city's existence "the crevasse period.")

A crevasse-induced flood in 1735 inundated practically all of New Orleans, which at that point consisted of forty-four square blocks. Sauvé's Crevasse was a breach that opened on the east bank of the Mississippi in May, 1849. A month later, a reporter for the Daily Picayune, surveying New Orleans from the cupola of the St. Charles Hotel, observed "one sheet of water, dotted in innumerable spots with houses." In 1858, forty-five crevasses opened up in Louisiana's levees; in 1874, forty-three; in 1882, two hundred and eighty-four.

In what's become known as the Great Flood of 1927, two hundred and twenty-six crevasses were reported. That flood inundated twenty-seven thousand square miles across half a dozen states. It displaced more than five hundred thousand people, caused an estimated five hundred million dollars' worth of damage (more than seven billion dollars in today's money), and marked a very wet watershed. "I woke up this mornin', can't even get out of my door," Bessie Smith lamented, in "Backwater Blues."

In response to the Great Flood, Congress, in effect, nationalized flood control along the Mississippi and entrusted the work to the Army Corps of Engineers. Joseph Ransdell, Louisiana's senior U.S. senator at the time, called the Flood Control Act of 1928 the most important piece of water-related legislation "since the world began." The Corps extended the levees-within four years, it had added another two hundred and fifty miles' worth-and strengthened them. (On average, the levees were raised by three feet, while their volume almost doubled.) The Corps also added a new feature-spillways, like the Bonnet Carré. When the river was at flood stage, the spillway gates would open, relieving pressure on the levees. A poem commemorating the Corps' efforts declared:

The plan was an engineer masterpiece
Fashioned by experts, a grand bas-relief
Levees, floodways, and other improvements
Blended into a project beneficent.

Thanks to the "project beneficent," the crevasse period drew to an end. This was a comfort to the millions of people who had settled (and resettled) in the floodplain. But with the end of river flooding came an end to fresh sediment. In the succinct formulation of Davis, the L.S.U. geographer: "The Mississippi River was controlled; land was lost; the environment changed."

C.P.R.A.'s "bold" scheme for saving Plaquemines is to rehabilitate the crevasse for the post-crevasse era. The agency's master plan calls for punching eight giant holes through the levees on the Mississippi and two more through those on its main distributary, the Atchafalaya. The openings will be gated and channelized, and the channels will themselves be leveed. C.P.R.A. likes to characterize the effort as a form of restoration, a way to reëstablish natural processes. And that's true, but only in the sense that trucking salmon upstream, or using planes to train whooping cranes to migrate, is natural.

The first artificial crevasse scheduled to be built is a project known as the Mid-Barataria Sediment Diversion. The diversion will be six hundred feet wide and thirty feet deep. It will start on the west bank of the Mississippi, some thirty-five miles upriver of Buras, then, in evident defiance of hydrology, run in a perfectly straight line due west for two and a half miles, to Barataria Bay. When it's operating at maximum capacity, some seventy-five thousand cubic feet of water will flow through it every second. In terms of weight, that's a fully loaded aircraft carrier's worth every minute. For comparison's sake, the Hudson River's average flow is twenty thousand cubic feet per second. Nothing quite like it has ever been attempted before. "It's one of a kind," Barth told me.

Currently, the bill for the project is estimated at $1.4 billion. The next diversion in line, the Mid-Breton, which is planned for the east bank of Plaquemines, is priced at eight hundred million dollars. Financing for both diversions is supposed to come out of the settlement fund from the BP oil spill, which, in 2010, spewed more than three million barrels of oil into the Gulf, fouling the coast from Texas to Florida. (Planning for the other diversions is still in a very early stage, and funding for them hasn't been secured.)

Many Plaquemines residents, like Lambert, welcome the diversions as the parish's last, best chance. "It's all about the sediment," Albertine Kimble, an outspoken proponent of the projects, and one of the few people in the parish who live outside the levees, told me. But there are also many who oppose the diversions. A few weeks before the meeting in Buras, Plaquemines' president had staged a public showdown with C.P.R.A. by denying the authority permits to take soil samples at the site of the Mid-Barataria project. The authority had taken them anyway, with a state trooper standing guard.

At Cajun Fishing Adventures, Barth clicked through slides showing where the Mid-Barataria diversion would go and how it would be constructed, over a period of up to five years. An animation of the process revealed it to be almost incomprehensibly complex, involving relocating a rail line, rerouting Route 23, and assembling the enormous gates out of floating sections. Once the structure was completed, Barth explained, the gates would be opened when the river was at flood stage and carrying the most sand. After a few years, enough sediment would be deposited in Barataria Bay that terra semi-firma would start to form. The diversion would be powered by the river itself, instead of by pumps, and, in contrast with projects like BA-39, it would continue to deliver sediment year after year.

"When we talk about a sediment diversion, what's the main purpose?" Barth said. "It's to maximize the sediment and minimize the freshwater."

A man in the corner of the room raised his hand. "I assume you're going to build it," he said of the Mid-Barataria project. "But what is the damage going to be?" Despite Barth's assurances, the man was worried about how much freshwater would be directed into the basin and how that would affect recreational fishing. "Speckled trout will be done," he declared.

"If this were a natural crevasse, I'd be all for it," he said. "But, when we as humans intervene, it rarely turns out well. That's why we are where we are today."

Soon it would be too hot.

It was another sticky day, and I'd circled back to New Orleans to meet up with a coastal geologist named Alex Kolker. Kolker teaches at the Louisiana Universities Marine Consortium, and, as a pedagogical sideline, he sometimes organizes excursions around the city. Unlike more conventionally popular tours, which feature ghosts, voodoo, and pirates, his emphasize hydrology. He'd agreed to take me on one, though, he'd warned, we'd have to leave early; by noon, the streets would be a sauna.

"This city was built largely by the river," Kolker observed, as we set out. We were travelling by bike from the Garden District, which was still sound asleep. "And the short story is that the high ground is near the river and the low ground is old swamps and old marshes." We pedalled north on Josephine Street, away from the Mississippi and imperceptibly downhill. Lofty mansions gave way to shotgun houses in various states of renewal and disrepair.

Kolker braked at an enormous pothole. It had been patched with asphalt, and this patch had developed a new pothole of its own.

"Subsidence happens on a couple of different scales," he observed. "You have the big scale, where the old marshes are degrading. And then you have smaller-scale features, like this." A bit farther on, we came to a manhole cover sticking out of the street like a turret.

"The manhole is probably anchored, and so it doesn't sink, or, at least, it doesn't sink as fast as the ground around it," Kolker explained. A sign nearby read "Evacuation Route."

In the sunny literature aimed at tourists, New Orleans is called the Crescent City (for the curve of the Mississippi it was built along) or the Big Easy (for its laid-back vibe). In a less upbeat context, residents refer to it as the "bowl." By now, most of the bowl lies at or below sea level-some spots as much as fifteen feet below. When you're in the city, it's hard to imagine the entire place sinking underneath you, and yet it is. A recent study that relied on satellite data found some sections of New Orleans dropping by almost half a foot per decade. "That's one of the fastest rates on Earth," Kolker noted.

After a few more stops to admire various swales and depressions-"There's a sinkhole over there!"-we arrived at the Melpomene Pumping Station. By this point, we were in Broadmoor, a low-lying neighborhood sometimes called "Floodmoor." The station was locked, but through its windows I could see a series of what looked like rockets resting on their sides. These were Wood Screw Pumps, so named for their inventor, A. Baldwin Wood. Wood patented his design in 1920, a moment of particularly grandiloquent confidence in the power of engineering.

"New Orleans' drainage problem is a terrible one," a front-page article in the Item observed in May of that year. "To meet the problem, New Orleans has constructed the greatest drainage system in the world."

"Man every day is surpassing Nature," the article declared. "He has thrown back the giant Mississippi and made it go where it listeth not."

In 1920, New Orleans had six pumping stations, including the Melpomene. These allowed the "old swamps" to be drained and developed into new communities, such as Lakeview and Gentilly.

Today, there are twenty-four stations, which together operate a hundred and twenty pumps. During a storm, rain is funnelled into a Venice's worth of canals. Then it's channelled into Lake Pontchartrain. Without this system, large swaths of the city would quickly become uninhabitable.

But New Orleans's world-class drainage system, like its world-class levee system, is a sort of Trojan solution. Since marshy soils compact by de-watering, pumping water out of the ground exacerbates the very problem that needs to be solved. The more water that's pumped, the faster the city sinks. And, the more it sinks, the more pumping is required.

"Pumping is a big part of the issue," Kolker told me, as we climbed back onto our sweaty bicycles. "It accelerates subsidence, so it becomes a positive-feedback loop."

As we cycled on, the conversation turned to Katrina. Kolker moved to New Orleans about eighteen months after the storm hit. He recalled that, for several years, the "bathtub ring"-the citywide stain left behind by the floodwaters-was still clearly visible on the sides of most buildings.

"Here we're getting into areas that had five to eight feet of water," he told me at one point.

An unusually large storm, Katrina was far from a worst-case scenario. As it churned north, in the early morning hours of August 29, 2005, its eye passed to the east of the city; this meant that its strongest winds also passed to the east, over towns like Waveland and Pass Christian, in Mississippi. Briefly, it seemed that New Orleans had been spared.

But the storm was driving water into a network of channels on the city's eastern edge. These channels-the Industrial Canal, the Gulf Intercoastal Waterway, and the Mississippi River Gulf Outlet (otherwise known as Mr. Go)-had been dug for shipping, to provide a shortcut between the river and the sea. At around 7:45 A.M., the levees on the Industrial Canal failed, sending a twenty-foot-high wall of water crashing through the Lower Ninth Ward. At least six dozen people in the predominantly African-American neighborhood were killed. Water was also surging into Lake Pontchartrain. As the hurricane pushed inland, this water was forced south, out of the lake and into the city's drainage canals. The effect was like emptying a swimming pool into a living room. Soon the flood walls on the Seventeenth Street and London Avenue Canals gave way. By the next day, eighty per cent of the bowl was underwater.

Hundreds of thousands of people had evacuated New Orleans ahead of the storm. With the city inundated, it was unclear if they would return, or whether they should. "The Case Against Rebuilding the Sunken City of New Orleans," ran a headline in Slate a week after the hurricane.

"It is time to face up to some geological realities and start a carefully planned deconstruction of New Orleans," an op-ed in the Washington Post declared. The author, Klaus Jacob, a geophysicist and an expert on disaster risk management, suggested that, as a temporary fix, some of New Orleans could be converted "into a city of boathouses." The Mississippi could then be allowed to flood again, "to fill in the 'bowl' with fresh sediment." (Jacob went on to warn, in 2011, that New York City's subways would flood during a major storm, a prediction fulfilled the following year, by Superstorm Sandy.)

An advisory group appointed by New Orleans's mayor recommended that only the highest areas of the city-those along the river and atop what are known as the Gentilly and Metairie Ridges-be resettled. A public planning process should then be conducted, the group proposed, to determine which low-lying neighborhoods to reoccupy and which to abandon.

All sorts of radical ideas were put forward, and then shelved. Retreat might make geophysical sense; politically, it was a non-starter. And so the Corps was charged, yet again, with reinforcing the levees-in this case, against storm surges coming from the Gulf. South of the city, the Corps erected the world's largest pumping station, part of a $1.1-billion structure called the West Closure Complex. To the east, it constructed the Lake Borgne Surge Barrier, a concrete wall nearly two miles long and five and a half feet thick, which cost $1.3 billion. The Corps plugged the Mississippi River Gulf Outlet with a nine-hundred-and-fifty-foot-wide rock dam and installed massive gates and pumps between the drainage canals and Lake Pontchartrain. The pumps at the foot of the Seventeenth Street Canal were designed to move twelve thousand cubic feet of water per second, a flow greater than the Tiber's.

These outsized structures have kept the city dry during several post-Katrina storms. And, from a certain perspective, New Orleans now appears substantially better protected than when Katrina hit. But what looks like a defense from one angle can look like a trap from another. "You must have a replenished coast," Jeff Hebert, a former deputy mayor of New Orleans, told me. "Because as goes the coast, goes New Orleans." Since the close of the crevasse period, land loss to the south has brought the city some twenty miles closer to the Gulf. It's been estimated that for every three miles a storm has to travel over land its surge is reduced by a foot. If this is the case, then the threat to New Orleans has grown seven feet taller.

"Drive out nature though you will with a pitchfork," Horace wrote, in 20 B.C., "yet she will always hurry back, and, before you know it, will break through your perverse disdain in triumph."

Toward the end of our subsidence tour, Kolker and I cycled through the French Quarter, where, although it was still early, tourists armed with drinks were jamming the streets. In Woldenberg Park, we got up on top of the levees and could look out over the Mississippi, toward Algiers.

I asked Kolker how he saw the future. "Sea level will continue to rise," he said. The diversions planned for Plaquemines would add some land back to the marshes south of the city, and so, too, would more conventional dredging projects, like BA-39. "But I think the areas that don't get restored will flood more and more frequently. There will be continued wetland loss." The city once known as L'Isle de la Nouvelle Orléans would, in coming years, Kolker predicted, "look more and more like an island."

Isle de Jean Charles, in Terrebonne Parish, lies fifty miles southwest of New Orleans and sixty miles due east of Buras, along the moldering instep of Louisiana's boot. It can be reached by a single, narrow causeway that used to run over marshland. Now you can fish from your car.

"In the springtime, there's always water on the road, whenever there's a south wind," Boyo Billiot told me. We were standing in the back yard of the house he had grown up in, which his mother, who is ninety-four, still occupies. It teetered above us on twelve-foot pilings. Several American flags fluttered from the aerial porch. It was winter, and the tail end of deer-hunting season. Billiot was dressed in camouflage. His phone kept dinging with messages from hunting buddies wondering where he was.

Billiot is a broad man with a gravelly voice and a salt-and-pepper goatee. He can trace his ancestry back to Jean Charles Naquin, who gave the island its name, in the early eighteen-hundreds. (The eponymous Jean Charles was an associate of the notorious pirate Jean Lafitte.) Naquin had a son, Jean Marie, who married a Native American woman and escaped to the island after his father disowned him. Jean Marie's children, in turn, married descendants of three tribes-the Biloxi, the Chitimacha, and the Choctaw. Most of their children remained on the island, where they formed their own tightly knit, largely self-sufficient society.

"They went for years and years and nobody knew there was anybody living here," Billiot told me. "When they had the Great Depression, they didn't know anything about it over here, because it didn't affect them."

Billiot grew up on Isle de Jean Charles in the nineteen-fifties, speaking a mixture of Cajun French and Choctaw. "Everybody knew each other, from one end of the island to the other," he recalled. People still earned a living mostly from fishing, oystering, and trapping. His father had had a shrimp boat that he would dock right in front of the house. In those days, a deep bayou ran the length of the island, and people crabbed in it. The road, which had just been built, didn't get much use, because the island had its own grocery stores.

Today, the island's stores are all gone. There are about forty houses left, most of them raised up on pilings, and many of them abandoned. Since Billiot was a child, the island has shrunk from thirty-five square miles to half a square mile-a loss in area of more than ninety-eight per cent.

The island is disappearing for all the usual reasons. It's part of an ancient delta lobe whose soil is compacting. Sea levels are rising. In the early part of the twentieth century, it lost its main sources of fresh sediment to flood-control measures. Then came the oil industry, which dug canals through the wetlands. The canals pulled in salt water, and, as the salinity rose, the reeds and marsh grasses died. The die-off widened the channels, allowing in more salt water, causing more die-off and more widening.

"It's almost like when we used to have video players and you'd hold down the fast-forward button to get where you wanted to in a movie," Billiot's daughter, Chantel Comardelle, told me. She was sitting in the kitchen of the elevated house with Billiot's mother, whom she calls maman. The walls were lined with family photos. "Those canals just held the fast-forward button on the problem."

After a pair of hurricanes in the nineteen-eighties flooded the trailer they were living in, Billiot and Comardelle and the rest of their immediate family moved off the island. With each successive storm, another chunk of land was lost and more families left. In the early two-thousands, a ring of levees was erected around the remnants of Isle de Jean Charles. These turned the bayou where people had once fished and crabbed into a narrow, stagnant pond. Inside the levees, land loss slowed. Outside and along the road, it only got worse.

Even at this point, steps could have been taken to preserve what was left of Isle de Jean Charles. Plans for a massive hurricane-protection system, known as the Morganza to the Gulf project, were being drawn up and could have been extended to include the island. But in this case the Corps recommended against more engineering. Building the extension would have added a hundred million dollars to the project's billion-dollar price tag and preserved just three hundred soupy acres. (The cost of the project has since ballooned to ten billion dollars.) For that much money, you could buy as much land in, say, Chicago.

The residents of the island, as well as the families who have moved off it in recent decades, are virtually all members of the Isle de Jean Charles band of the Biloxi-Chitimacha-Choctaw Tribe. Comardelle is the band's secretary, Billiot is a deputy chief, and the band's chief is Billiot's uncle, Albert Naquin. When it became clear that the road and then, ultimately, the isle itself were going to be allowed to wash away, a plan was drawn up to move the entire community inland. For the first phase of construction, the band applied for a fifty-million-dollar federal grant, which was awarded in 2016. At the time of my visit, though, the money had become tied up in state politics, and the plan seemed to be in the process of unravelling.

As I wandered past empty homes plastered with " No Trespassing " signs, I could see the economic logic of the island's "planned deconstruction." At the same time, the injustice was pretty glaring. The Biloxi and the Choctaw had come to Louisiana after they'd been dispossessed of ancestral lands farther east. The Isle de Jean Charles band had been able to live peacefully on the island only because it was too isolated and commercially irrelevant for anyone else to take an interest in. The band had had no say in the dredging of the oil channels or in the layout of the Morganza to the Gulf project. They'd been excluded from the efforts to control the Mississippi, and, now that new forms of control were being imposed to counter the effects of the old, they were being excluded from those, too.

"It's kind of hard to imagine that no one's going to be living here," Billiot told me. "But I've watched it erode away."

From a distance, the Old River Control Auxiliary Structure looks like a row of sphinxes attached at the ears. The structure is four hundred and forty feet long and a hundred feet high. When you get close enough, you can see that the heads of the sphinxes are really cranes and the haunches steel gates. If there is a single feat of engineering that can stand for the centuries-long effort to dominate the Mississippi-to make it "go where it listeth not"-the Auxiliary Structure might be it. Unlike a levee or a spillway, built to stop the river from flooding, it was put up to stop time.

The Auxiliary Structure sits on a broad plain about eighty miles upriver from Baton Rouge. Near this spot, some five hundred years ago, the Mississippi went on a bender, creating a kind of hydrological as well as nomenclatural hair ball. The meander took the Mississippi so far west that it ran into the Atchafalaya, at that time a distributary of a different river, the Red, which itself was a Mississippi tributary. The Atchafalaya is a good deal shorter and steeper than the last few hundred miles of the Mississippi, and the tangle presented the water in the larger river with a choice. It could follow its old path to the Gulf, via the Bird's Foot, or it could switch routes and take the faster path offered by the Atchafalaya. Until the mid-eighteen-hundreds, an enormous logjam on the Atchafalaya, which was dense enough to walk across, complicated this choice. But once the jam was removed-by, among other means, nitroglycerin-more and more water began flowing out of the main stem of the Mississippi. As the flow on the Atchafalaya increased, it widened and deepened.

In the ordinary course of events, the Atchafalaya would have kept widening and deepening until, eventually, it captured the lower Mississippi entirely. This would have left New Orleans low and dry and rendered the industries that had grown up along the river-the refineries, the grain elevators, the container ports, and the petrochemical plants-essentially worthless. Such an eventuality was thought to be unthinkable, and so, in the nineteen-fifties, the Corps stepped in. It dammed the former meander, known as Old River, and dug two huge, gated channels. The river's choice would now be dictated for it, its flow maintained as if it were forever the Eisenhower era.

Long before I caught sight of the Auxiliary Structure, I'd read about it in John McPhee's classic piece " Atchafalaya," a morality tale of a darkly comic cast that appeared in this magazine, in 1987. In McPhee's telling, the Corps throws its heart-and millions of tons of concrete-into forestalling the Mississippi's avulsion, and believes that it has succeeded. "The Corps of Engineers can make the Mississippi River go anywhere the Corps directs it to go," one general avers, after a narrow brush with disaster, in 1973, when control of Old River Control was nearly lost. McPhee writes admiringly of the Corps' grit, determination, even genius, but running through the essay is a strong countercurrent. Is the Corps just kidding itself? Are we all?

"Atchafalaya," McPhee writes. "The word will now come to mind more or less in echo of any struggle against natural forces-heroic or venal, rash or well advised-when human beings conscript themselves to fight against the Earth, to take what is not given, to rout the destroying enemy, to surround the base of Mt. Olympus demanding and expecting the surrender of the gods."

I showed up at Old River Control on a lovely Sunday afternoon in late winter. The Corps' office, tucked behind a formidable iron fence, looked empty. But, when I pressed on a buzzer by the driveway, the intercom crackled to life and a natural-resource specialist named Joe Harvey came out to meet me. He was dressed as if he were about to go fishing, with his pants tucked into big rubber boots. He led me out to a gazebo overlooking the Auxiliary Structure and its outflow channel.

As the water in the channel swirled by, we chatted about fluvial history. "In 1900, about ten per cent of the Red River and the Mississippi put together was going down the Atchafalaya," Harvey explained. "In 1930, you had about twenty per cent. By 1950, you had thirty per cent." This was the trend line that prompted the Corps to step in.

"We still do the seventy-thirty division," Harvey said. Every day, engineers measure the flow on the Red and the Mississippi and adjust the gates accordingly. On this particular Sunday, they were allowing through some forty thousand cubic feet per second.

"From here down to the mouth of the Mississippi is about three hundred and fifteen miles," Harvey said. "And from here to the mouth of Atchafalaya is about a hundred and forty miles. So it's about half the distance. So the river wants to go this way. But if that happens . . ." His voice trailed off.

Two people were fishing on the outflow channel, from a little motorboat, and I asked Harvey what they might catch. "Oh, we have everything that's in the Mississippi," he said. "Of course, now there's a whole lot of carp, and that's not so good." He was referring to Asian carp, which were brought over from China in the nineteen-sixties and seventies. The fish, which had been imported to provide algae control, escaped from hatcheries during flood season and found their way into the Mississippi, and from there into virtually all of the river's major tributaries. In some stretches of the Illinois River, Asian carp now make up ninety per cent of the fish stock by weight. Like the dissolution of the Louisiana coast, the carpification of the Mississippi basin is a man-made natural disaster. And here, as well, the Corps has been called in. In an effort to keep the fish from swimming into Lake Michigan, it has spent tens of millions of dollars installing electric carp barriers.

"They're still trying to keep them out of the Great Lakes," Harvey said. "Here, they're just everywhere."

McPhee included "Atchafalaya" in his book " The Control of Nature," published in 1989. Since then, a lot has happened to complicate the meaning of "control," not to mention "nature." Choose just about any metric you want and it tells the same story. Through activities like farming, mining, and clear-cutting, people have directly transformed more than half the ice-free land on Earth-some twenty-seven million square miles-and we've indirectly altered half of what remains. As with the Mississippi, we have dammed or leveed most of the world's major rivers. Our fertilizer plants and legume crops fix more nitrogen than all terrestrial ecosystems combined, and our planes, cars, and power stations emit about a hundred times more carbon dioxide than volcanoes. We now routinely cause earthquakes. (A particularly damaging human-induced quake that shook Pawnee, Oklahoma, on the morning of September 3, 2016, was felt all the way in Des Moines.) In terms of sheer biomass, the numbers are stark-staring: today, people outweigh wild mammals by a ratio of more than eight to one. Add in the weight of our domesticated animals-mostly cows and pigs-and that ratio climbs to twenty-three to one. "In fact," as a recent paper in the Proceedings of the National Academy of Sciences observed, "humans and livestock outweigh all vertebrates combined, with the exception of fish." We have become the major driver of extinction and also, probably, of speciation. In the age of man, there is nowhere to go-and this includes the deepest trenches of the oceans and the middle of the Antarctic ice sheet-that does not already bear our Friday-like footprints.

Atmospheric warming, ocean warming, ocean acidification, sea-level rise, deglaciation, desertification, eutrophication-these are just some of the byproducts of our species' success. Such is the pace of what is blandly labelled "global change" that there are only a handful of comparable examples in Earth's history, the most recent being the asteroid impact that ended the reign of the dinosaurs, sixty-six million years ago. Humans are producing no-analogue climates, no-analogue ecosystems, a whole no-analogue future. At this point, it might be prudent to scale back our commitments and reduce our impacts. But there are so many of us-nearly eight billion-and we are stepped in so far, return seems impracticable.

And so we face a no-analogue predicament. If there is to be an answer to the problem of control, it's going to be more control. Only now what's to be managed is not a nature that exists-or is imagined to exist-apart from the human. Instead, the new effort begins with a planet remade, and spirals back on itself-not so much the control of nature as the control of (the control of) nature. A Mississippi that's been harnessed, straightened, regularized, and shackled can still exert a godlike force; it's no longer exactly a river, though. It's hard to say who, these days, occupies Mt. Olympus, if anyone. ♦

This article appears in the print edition of the April 1, 2019, issue, with the headline "Under Water."

Elizabeth Kolbert has been a staff writer at The New Yorker since 1999. She won the 2015 Pulitzer Prize for general nonfiction for " The Sixth Extinction: An Unnatural History."
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The New Orleans Lakefront Airport was built by the Louisiana governor Huey P. Long on a tongue of fill that sticks out into Lake Pontchartrain. Its terminal was designed by the same architect Long had used to build a new Louisiana state capitol and a new governor's mansion, and it was originally named for one of Long's cronies, Abraham Shushan.

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This could revolutionize how we think about the formation of Earth - it may be that it started out with a lot of the water already here rather than raining down on us via comets.

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A battered diamond that survived a trip from "hell" confirms a long-held theory: Earth's mantle holds an ocean's worth of water.

"It's actually the confirmation that there is a very, very large amount of water that's trapped in a really distinct layer in the deep Earth," said Graham Pearson, lead study author and a geochemist at the University of Alberta in Canada. The findings were published today (March 12) in the journal Nature.

The worthless-looking diamond encloses a tiny piece of an olivine mineral called ringwoodite, and it's the first time the mineral has been found on Earth's surface in anything other than meteorites or laboratories. Ringwoodite only forms under extreme pressure, such as the crushing load about 320 miles (515 kilometers) deep in the mantle.
What's in the mantle?
Most of Earth's volume is mantle, the hot rock layer between the crust and the core. Too deep to drill, the mantle's composition is a mystery leavened by two clues: meteorites, and hunks of rock heaved up by volcanoes. First, scientists think the composition of the Earth's mantle is similar to that of meteorites called chondrites, which are chiefly made of olivine. Second, lava belched by volcanoes sometimes taps the mantle, bringing up chunks of odd minerals that hint at the intense heat and pressure olivine endures in the bowels of the Earth.

In recent decades, researchers have also recreated mantle settings in laboratories, zapping olivine with lasers, shooting minerals with massive guns and squeezing rocks between diamond anvils to mimic the Earth's interior.

These laboratory studies suggest that olivine morphs into a variety of forms corresponding to the depth at which it is found. The new forms of crystal accommodate the increasing pressures. Changes in the speed of earthquake waves also support this model. Seismic waves suddenly speed up or slow down at certain depths in the mantle. Researcher think these speed zones arise from olivine's changing configurations. For example, 323 to 410 miles (520 to 660 km) deep, between two sharp speed breaks, olivine is thought to become ringwoodite. But until now, no one had direct evidence that olivine was actually ringwoodite at this depth. [ Infographic: What is Earth Made Of?]

"Most people (including me) never expected to see such a sample. Samples from the transition zone and lower mantle are exceedingly rare and are only found in a few, unusual diamonds," Hans Keppler, a geochemist at the University of Bayreuth in Germany, wrote in a commentary also published in Nature today.
Earth's deepest ocean
The diamond from Brazil confirms that the models are correct: Olivine is ringwoodite at this depth, a layer called the mantle transition zone. And it resolves a long-running debate about water in the mantle transition zone. The ringwoodite is 1.5 percent water, present not as a liquid but as hydroxide ions (oxygen and hydrogen molecules bound together). The results suggest there could be a vast store of water in the mantle transition zone, which stretches from 254 to 410 miles (410 to 660 km) deep.

"It translates into a very, very large mass of water, approaching the sort of mass of water that's present in all the world's ocean," Pearson told Live Science's Our Amazing Planet.

Plate tectonics recycles Earth's crust by pushing and pulling slabs of oceanic crust into subduction zones, where it sinks into the mantle. This crust, soaked by the ocean, ferries water into the mantle. Many of these slabs end up stuck in the mantle transition zone. "We think that a significant portion of the water in the mantle transition zone is from the emplacement of these slabs," Pearson said. "The transition zone seems to be a graveyard of subducted slabs."

Keppler noted that it's possible the volcanic eruption that brought the deep diamond to Earth's surface may have sampled an unusually water-rich part of the mantle, and that not all of the transition-zone layer may be as wet as indicated by the ringwoodite.

"If the source of the magma is an unusual mantle reservoir, there is the possibility that, at other places in the transition zone, ringwoodite contains less water than the sample found by Pearson and colleagues," Keppler wrote. "However, in light of this sample, models with anhydrous, or water-poor, transition zones seem rather unlikely."
Ride on a rocket
A violent volcanic eruption called a kimberlite quickly carried this particular diamond from deep in the mantle. "The eruption of a kimberlite is analogous to dropping a Mentos mint into a bottle of soda," Pearson said. "It's a very energetic, gas-charged reaction that blasts its way to Earth's surface."

The tiny, green crystal, scarred from its 325-mile (525 km) trip to the surface, was bought from diamond miners in Juína, Brazil. The mine's ultradeep diamonds are misshapen and beaten up by their long journey. "They literally look like they've been to hell and back," Pearson said. The diamonds are usually discarded because they carry no commercial value, he said, but for geoscientists, the gems provide a rare peek into Earth's innards. [ Shine On: Photos of Dazzling Mineral Specimens]

The ringwoodite discovery was accidental, as Pearson and his co-authors were actually searching for a means of dating the diamonds. The researchers think careful sample preparation is the key to finding more ringwoodite, because heating ultradeep diamonds, as happens when scientists polish crystals for analysis, causes the olivine to change shape.

"We think it's possible ringwoodite may have been found by other researchers before, but the way they prepared their samples caused it to change back to a lower-pressure form," Pearson said.

Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Rare Diamond Confirms That Earth's Mantle Holds an Ocean's Worth of Water

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A battered diamond that survived a trip from "hell" confirms a long-held theory: Earth's mantle holds an ocean's worth of water. "It's actually the confirmation that there is a very, very large amount of water that's trapped in a really distinct layer in the deep Earth," said Graham Pearson, lead study author and a geochemist at the University of Alberta in Canada.

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Scientists offer a new way to accurately map coral reefs using a combination of Earth-orbiting satellites and field observations. This first-ever global coral reef atlas contains maps of over 65,000 square kilometers (25,097 square miles) of coral reefs and surrounding habitats.

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A study from scientists at the Khaled bin Sultan Living Oceans Foundation and the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science offers a new way to accurately map coral reefs using a combination of Earth-orbiting satellites and field observations. This first-ever global coral reef atlas contains maps of over 65,000 square kilometers (25,097 square miles) of coral reefs and surrounding habitats.

The maps, published today in the journal Coral Reefs, are the result of a 10-year Global Reef Expedition by scientists for the Khaled bin Sultan Living Oceans Foundation. The expedition traveled to over 1,000 remote coral reefs in 15 countries, mapping and surveying the reefs down to a one-square meter scale to better understand their health and resiliency. Many of the reefs visited on the expedition had never been studied before.

The high-resolution coral reef maps contain information on shallow water marine habitat such as fore and back reefs as well as information on the size of seagrass beds and mangrove forests for key locations visited on the expedition. All of these coastal habitats are key components of tropical coastal ecosystems and help to filter water, protect the coast from storms, and provide key nursery habitat for commercial and subsistence fisheries. They also face increasing threats from coastal development, overfishing, and climate change.

To develop the new model to accurately map coral reef and other tropical shallow-water marine habitats, scientists took data collected from extensive SCUBA surveys conducted on the Global Reef Expedition and extrapolate that information across the entire reef using ultra-high-resolution satellite imagery. By comparing the maps with video footage from cameras dropped at precise coordinates along the reef, the scientists were able to verify the accuracy of their new mapping method.

"In order to conserve something, it's imperative to know where it is located and how much of it you have," said Sam Purkis, professor and chair of the UM Rosenstiel School Department of Marine Geosciences. "Developing such an understanding for coral reefs is especially challenging because they are submerged underwater and therefore obscured from casual view. With this study, we demonstrate the potential to use satellite images to make coral reef maps at global scale."

Scientists now have a way to peer beneath the waves to accurately map large areas of coral reefs at greatly reduced cost. Traditional coral reef surveys are expensive to conduct and limited in scope, requiring hours of underwater surveys conducted by highly-trained scientific divers. Using this new model, scientists can create detailed coral reef habitat maps at a regional scale without having to survey the entire reef in person.

"Satellite, aircraft, and drone imaging will become an increasingly important tool for addressing the coral reef crisis at the global scale at which it's occurring." said Purkis, also the interim chief scientist for the Living Oceans Foundation.

The high-resolution coral reef maps made for this study can be found on the World Reef Map, an interactive coral reef atlas where users can explore all of the coral reefs and shallow water marine habitats mapped on the Global Reef Expedition.

Although they by no means cover every reef worldwide, this new atlas covers a meaningful portion of key reef provinces around the world. It also provides much-needed baseline data of coral reef health prior to the 2017 mass bleaching event. This digital resource has been made available to the public so that governments and conservation organizations can use these maps to protect and restore their coral reefs for generations to come.

Scientists estimate that over 50 percent of coral reefs worldwide have been lost in the past 40 years due to climate change and other human pressures. These new detailed habitat maps can help local resource managers identify areas that may be in greatest need of conservation action.

"Benthic habitat maps are an essential tool in coral reef conservation as they provide a snapshot of where reefs are located and the status of their health," said Alexandra Dempsey, the director of science management for the Khaled bin Sultan Living Oceans Foundation and a co-author of the paper. "Scientists will use these habitat maps as baseline data to help track changes in reef composition and structure over time."

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marine biology; sea life; fish; satellites; space station; space exploration; coral reefs; ecology; geography

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Largest collection of coral reef maps ever made: New global atlas offers new way to map coral reefs from space

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Scientists offer a new way to accurately map coral reefs using a combination of Earth-orbiting satellites and field observations. This first-ever global coral reef atlas contains maps of over 65,000 square kilometers (25,097 square miles) of coral reefs and surrounding habitats.

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This article goes over new evidence for The Great Dying. Pretty Interesting read! - Kaitlyn Gardner

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Researchers say mercury buried in ancient rock provides the strongest evidence yet that volcanoes caused the biggest mass extinction in the history of the Earth.

The extinction 252 million years ago was so dramatic and widespread that scientists call it "the Great Dying." The catastrophe killed off more than 95 percent of life on Earth over the course of hundreds of thousands of years.

Paleontologists with the University of Cincinnati and the China University of Geosciences said they found a spike in mercury in the geologic record at nearly a dozen sites around the world, which provides persuasive evidence that volcanic eruptions were to blame for this global cataclysm.

The study was published this month in the journal Nature Communications.

The eruptions ignited vast deposits of coal, releasing mercury vapor high into the atmosphere. Eventually, it rained down into the marine sediment around the planet, creating an elemental signature of a catastrophe that would herald the age of dinosaurs.

"Volcanic activities, including emissions of volcanic gases and combustion of organic matter, released abundant mercury to the surface of the Earth," said lead author Jun Shen, an associate professor at the China University of Geosciences.

The mass extinction occurred at what scientists call the Permian-Triassic Boundary. The mass extinction killed off much of the terrestrial and marine life before the rise of dinosaurs. Some were prehistoric monsters in their own right, such as the ferocious gorgonopsids that looked like a cross between a sabre-toothed tiger and a Komodo dragon.

The eruptions occurred in a volcanic system called the Siberian Traps in what is now central Russia. Many of the eruptions occurred not in cone-shaped volcanoes but through gaping fissures in the ground. The eruptions were frequent and long-lasting and their fury spanned a period of hundreds of thousands of years.

"Typically, when you have large, explosive volcanic eruptions, a lot of mercury is released into the atmosphere," said Thomas Algeo, a professor of geology in UC's McMicken College of Arts and Sciences.

"Mercury is a relatively new indicator for researchers. It has become a hot topic for investigating volcanic influences on major events in Earth's history," Algeo said.

Researchers use the sharp fossilized teeth of lamprey-like creatures called conodonts to date the rock in which the mercury was deposited. Like most other creatures on the planet, conodonts were decimated by the catastrophe.

The eruptions propelled as much as 3 million cubic kilometers of ash high into the air over this extended period. To put that in perspective, the 1980 eruption of Mount St. Helens in Washington sent just 1 cubic kilometer of ash into the atmosphere, even though ash fell on car windshields as far away as Oklahoma.

In fact, Algeo said, the Siberian Traps eruptions spewed so much material in the air, particularly greenhouse gases, that it warmed the planet by an average of about 10 degrees centigrade.

The warming climate likely would have been one of the biggest culprits in the mass extinction, he said. But acid rain would have spoiled many bodies of water and raised the acidity of the global oceans. And the warmer water would have had more dead zones from a lack of dissolved oxygen.

"We're often left scratching our heads about what exactly was most harmful. Creatures adapted to colder environments would have been out of luck," Algeo said. "So my guess is temperature change would be the No. 1 killer. Effects would exacerbated by acidification and other toxins in the environment."

Stretching over an extended period, eruption after eruption prevented the Earth's food chain from recovering.

"It's not necessarily the intensity but the duration that matters," Algeo said. "The longer this went on, the more pressure was placed on the environment."

Likewise, the Earth was slow to recover from the disaster because the ongoing disturbances continued to wipe out biodiversity, he said.

Earth has witnessed five known mass extinctions over its 4.5 billion years.

Scientists used another elemental signature -- iridium -- to pin down the likely cause of the global mass extinction that wiped out the dinosaurs 65 million years ago. They believe an enormous meteor struck what is now Mexico.

The resulting plume of superheated earth blown into the atmosphere rained down material containing iridium that is found in the geologic record around the world.

Shen said the mercury signature provides convincing evidence that the Siberian Traps eruptions were responsible for the catastrophe. Now researchers are trying to pin down the extent of the eruptions and which environmental effects in particular were most responsible for the mass die-off, particularly for land animals and plants.

Shen said the Permian extinction could shed light on how global warming today might lead to the next mass extinction. If global warming, indeed, was responsible for the Permian die-off, what does warming portend for humans and wildlife today?

"The release of carbon into the atmosphere by human beings is similar to the situation in the Late Permian, where abundant carbon was released by the Siberian eruptions," Shen said.

Algeo said it is cause for concern.

"A majority of biologists believe we're at the cusp of another mass extinction -- the sixth big one. I share that view, too," Algeo said. "What we should learn is this will be serious business that will harm human interests so we should work to minimize the damage."

People living in marginal environments such as arid deserts will suffer first. This will lead to more climate refugees around the world.

"We're likely to see more famine and mass migration in the hardest hit places. It's a global issue and one we should recognize and proactively deal with. It's much easier to address these problems before they reach a crisis."

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extinction; nature; endangered plants; volcanoes; global warming; natural disasters; dinosaurs; fossils; early climate

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New evidence suggests volcanoes caused biggest mass extinction ever: Mercury found in ancient rock around the world supports theory that eruptions caused 'Great Dying' 252 million years ago.

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Researchers say mercury buried in ancient rock provides the strongest evidence yet that volcanoes caused the biggest mass extinction in the history of the Earth. The extinction 252 million years ago was so dramatic and widespread that scientists call it 'the Great Dying.'

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This helps validate assumptions about the early universe.

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Everything has a beginning. That's true for stories, for people, for the universe and even for chemistry. The Big Bang itself produced just a handful of elements (variations of hydrogen, helium and lithium nuclei), so researchers have a pretty good sense of what the first atoms and molecules might have been. But the very first molecular bond to form, linking together atoms of different elements in a single molecule, has long been missing in action.

Known as a helium hydride ion (HeH+), this conglomeration of basic bits is just a helium atom and a hydrogen's nucleus (aka a proton) stuck together. As the first compound created in the universe, you'd expect there to be traces of it throughout the universe - but astronomers couldn't find it. (Scientists managed to produce some in the lab in 1925, so at least they knew it wasn't an impossible substance.)

However, just as researchers wondered if they might've gotten things wrong about the early universe (or basic chemistry), fortune smiled on them: A paper today in describes the first unequivocal discovery of the HeH+ molecule in space. It took precise instruments and a flying observatory to do it, but now chemists and cosmologists alike can breathe easy - and push their research in new directions.

SOFIA So Fine

Ever since the 1970s, astronomers had been looking for HeH+ molecules in the hazy collections of gas and dust known as nebulas. Some in particular, called planetary nebulas, could mimic conditions in the early universe, so they became the biggest targets. But for decades, astronomers found nothing. (Well, nothing definite, at least; some helium hydride findings came in, but they all remained unconfirmed.)

Part of the problem was that the kind of light the molecule gives off is easily absorbed by Earth's atmosphere. The very air around most observatories was blocking out the molecule's signature. So to get a good look, scientists had to literally rise above all that.

Most observatories are built high up on mountains for lots of reasons, but even that wasn't good enough for this search. Instead, astronomers turned to the Stratospheric Observatory for Infrared Astronomy, or just SOFIA, which is literally an observatory aboard a plane. They took their telescope above all that blocking air, and finally saw clear and unambiguous emissions of the HeH+ ion, coming from a planetary nebula named NGC 7027, 2,900 light-years from Earth.

Molecule Manhunt

The finding opens a window into the behavior of planetary nebulas, and into this specific molecule (which formed differently in the distant past than in NGC 7027). Plus, it gives researchers better numbers to help them form more accurate theories and models.

But mostly, this is a symbolic victory, confirming some of the most basic things we think we know about the early universe, some 14 billion years ago.

As the study's authors put it: "The chemistry of the Universe began with this ion. The lack of definitive evidence for its very existence in interstellar space has been a dilemma for astronomy. The unambiguous detection reported here brings a decades-long search to a happy ending at last."

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Astronomers find oldest type of molecule in space

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Everything has a beginning. That's true for stories, for people, for the universe and even for chemistry. The Big Bang itself produced just a handful of elements (variations of hydrogen, helium and lithium nuclei), so researchers have a pretty good sense of what the first atoms and molecules might have been.

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Cryoseisms, also known as "frost quakes" or "ice quakes," may have been the reason loud booms and banging sounds were reported in the Chicago area, where brutally cold, below-zero wind chills have taken over.

The "frost quake" weather phenomenon occurs when the ground is saturated with water or ice.

Right now, that's the case in the Midwest, where many spots were recently covered with snow that then melted into the ground.

When there is a rapid drop in temperature, that saturated ground will quickly freeze.

(Julio Cortez/AP) Ice is seen on the side of the Great Falls National Historic Park as a couple takes in the sights during a frigid winter day, Jan. 30, 2019, in Paterson, N.J.

As that water underground suddenly freezes into ice, it then expands, causing the surrounding soil and rock to crack.

The cracking is what produces the loud noises -- or the "frost quake."

All of the ingredients were certainly there for "frost quakes" to occur in the Midwest Wednesday morning as wind chills plummeted well below zero.

The wind chill in Chicago clocked in at minus 52 degrees. The wind chill reached minus 55 degrees at the Minneapolis-Saint Paul International Airport.

Frost quakes were reported in Pennsylvania this week, according to WHP in Harrisburg, and in the Indianapolis area last week, according to WISH-TV.

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What is a 'frost quake'? Explaining the weather phenomenon

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Cryoseisms, also known as "frost quakes" or "ice quakes," may have been the reason loud booms and banging sounds were reported in the Chicago area, where brutally cold, below-zero wind chills have taken over. The "frost quake" weather phenomenon occurs when the ground is saturated with water or ice.

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It seems like future geologists may be able to identify the boundary between pre-human and post-human geologic history with this deposition layer.

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Amid the rugged peaks of the Vicdessos region of the French Pyrenees, the only visible signs of a human presence are a smattering of villages and the odd hiker or skier; it is considered a pristine environment. But even here, scientists have detected tiny pieces of plastic falling out of the air like artificial dust.

A first-of-its-kind study finds these particles have blown in on the wind from at least 100 kilometers away and likely much farther. This is a clear indication that atmospheric transport is yet another way plastic pollution is being distributed around the planet, even to remote areas. "And it suggests that this is a far bigger problem than we have currently thought about," says study co-author Deonie Allen, of the École Nationale Supérieure Agronomique de Toulouse (ENSAT).

The study, published Monday in Nature Geoscience, is one of only a handful that have attempted to measure how much plastic is falling from the atmosphere. It marks the first wave in what is likely to be a flood of such studies in the coming years, in an effort to fill in the picture of how microplastics move around the environment and how humans might be exposed to them.

"Nobody Had Looked Up"

Microplastics are tiny pieces that break off larger plastic items (such as bottles and bags) as they degrade in the environment, as well as the fibers that slough off synthetic fabrics. They come in a wide range of sizes-from a grain of rice down to a virus-and are made up of a complex variety of polymers and added chemicals.

Most research to detect microplastics in the environment has been done in the ocean, where they were first noticed, but scientists have slowly realized they are also present in freshwater systems, soil and the atmosphere. The first study to measure plastic fallout from the atmosphere- conducted in Paris -was published only in 2015. The recent attention to the issue means that there are only a handful of measurements of airborne plastic, and little sense of how the numbers might vary from place to place, depending on weather conditions and where the material is ultimately coming from.

Allen and her colleagues knew microplastics had been found in rivers and sediments in the Pyrenees, but no one had determined the sources. The bulk could not have come from local sources because of the small human population and limited industrial activity, so Allen was struck by a key question: "Why haven't we looked up?"

That is what she and her colleagues did, taking advantage of atmospheric measuring equipment already in place in the Pyrenees and sampling over five months. They found plastic fibers, films and shards, all in a range of sizes. Most of the polymers that turned up in the samples were polystyrene, polyethylene and polypropylene, which are all common in single-use plastic products such as bags and foam food containers.

A First Peek

Because the new study included smaller sizes of particles than previous studies, the researchers found more plastic particles overall; this bears out a recurring trend in microplastics research findings that the smaller the size of the particles, the more of them there are. When comparing only the size ranges examined in the 2015 Paris study, Allen and her colleagues found a similar amount of microplastic, which was unexpected given the disparate environments of the two studies. This could mean that the new study "gives us a background level of microplastic that you probably get pretty much everywhere in the world," says Melanie Bergmann, a marine ecologist with the Alfred Wegener Institute for Polar and Marine Research (AWI), who studies microplastics but was not involved in the new research. But because the samples were averaged over a whole month, it could be that the background level in the Pyrenees is lower but is punctuated by periodic plumes of microplastics coming in from populated areas.

The study did not pinpoint precisely where the microplastics originated, but used computer models of atmospheric currents to attempt to back-trace the air that brought them in-the first study to do so. They could only trace the air masses regionally, but were able to show the primary directions they came from. It was clear that the relatively small towns and villages were unlikely to account for all of the plastic they detected, which suggests the ultimate sources are more distant.

While such tracking is "an important step," says microplastic researcher Stephanie Wright, of King's College London, who wasn't involved in the research, "you kind of need to know the sources to understand the back trajectory more." Different plastics may be coming from different sources, and "an airstream could just pick up bits as it goes," she says.

The authors say their work is only a first peek at the larger airborne microplastics picture. Many more samples from across the world-as well as lab experiments that see how different shapes, types and sizes of plastics behave in different meteorological conditions-are needed to understand the full scope of the situation, including how much microplastics humans might be inhaling. Both Wright and Bergmann have pending studies that measure microplastic fallout in London and the Arctic, respectively, and these will add more data. Allen and her colleagues, too, are working to expand their research. Co-author Steve Allen, of ENSAT and the University of Strathclyde, says that "we should, in the next few years, get a much better picture of what's going on."

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Amid the rugged peaks of the Vicdessos region of the French Pyrenees, the only visible signs of a human presence are a smattering of villages and the odd hiker or skier; it is considered a pristine environment. But even here, scientists have detected tiny pieces of plastic falling out of the air like artificial dust.

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Tanis Deposits hold incredible K-Pg extinction event find.

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Mere minutes after a miles-wide asteroid slammed into Earth 66 million years ago, a hailstorm of tiny glass beads rained down on a flooding estuary in what's now North Dakota. As seismic waves from the impact thrashed the water, plants and animals were jumbled up and buried in the shifting sediments, which preserved the aftermath for millennia.

Now, researchers say this site-newly described in a paper in the Proceedings of the National Academy of Sciences-represents an exceedingly rare snapshot of the moment that marked the dinosaurs' demise. Handfuls of fossils have been found before at other places that also capture this moment in the geologic record, known as the K-Pg boundary. But the North Dakota site potentially represents an entire ecosystem affected by the catastrophe.

"Essentially, what we've got there is the geologic equivalent of high-speed film of the very first moments after the impact," says lead study author Robert DePalma, a Ph.D. student at the University of Kansas and a curator at the Palm Beach Museum of Natural History.

"To see organisms that would have been impacted by the actual event at the end of the Cretaceous is just stunning," adds coauthor Philip Manning, a paleontologist at the University of Manchester. ( See why some scientists think that volcanoes helped doom the dinosaurs.)

On Friday, The New Yorker published a feature describing the site-sometimes in more detail than the study itself provides. According to DePalma, the new PNAS paper will be just the first of several scientific studies that will fill in the details of this remarkable find.

So, what does the published data actually reveal so far? And what else might the site hold for paleontologists? We've got you covered.

Rain of glass

The North Dakota site, nicknamed Tanis after the "lost" ancient Egyptian city, lies on private ranch land within a tiny outcrop of the larger Hell Creek Formation, a series of rock layers that record the hundreds of millennia leading up to the dinosaurs' extinction.

DePalma first learned of the site from a fossil-dealer acquaintance, who had prospected there and found little he could sell for high value. Based on the fish, the dealer thought the site was a pond deposit that formed many thousands of years before the K-Pg boundary. But the more that DePalma mapped the site, the more he reconsidered. What if the site was in fact the low-lying portion of a river valley?

As described in the paper, DePalma found telltale signs of the K-Pg impact in the site's sediments, including bits of quartz shocked under the impact's immense pressure, as well as plenty of impact debris.

After the asteroid struck, it tore a gaping hole in Earth's crust some 50 miles wide and 18 miles deep, sending hunks of molten earth splashing upward and outward with ferocious speed. High in the atmosphere, the debris coalesced into tiny glass blobs, many of them less than a millimeter wide. These particles, called tektites, started raining down about 15 minutes after impact in a torrent of glass that didn't let up for another three quarters of an hour.

In many K-Pg sites, the tektites formed a discrete layer-but not at Tanis. The site's many layers of sediments are chock-full of tektites, which researchers interpret as a sign of water sloshing back and forth as the tektites fell. Tree resin at the site managed to catch some tektites before becoming fossilized as amber. DePalma's team even claims to have a tektite buried within the two-inch-deep hole it punched into sediment once it landed. After being flung onto land, a mass of fish became entombed all at once, and their exquisitely preserved bodies include gills congested with impact debris.

"It essentially stockpiled the rarest and most poorly represented things in [the rock formation] in one deposit that we can study for decades-and that's without even including the impact scenario," DePalma says. ( Here's why some experts think the asteroid hit just the right spot to cause the mass extinction.)

Ken Lacovara, a paleontologist at Rowan University who was not on the study team, points out that more than 350 sites around the world preserve the K-Pg boundary, and some of these sites also bear fossils. In 1987, paleontologists described shark teeth and clam shells at a K-Pg site in central Poland. In 2013, researchers in Denmark found isolated shark teeth within the clays laid down by the impact's fallout. But Manning and other researchers who have seen the fossils up close stress that Tanis stands alone.

"It's just mind-boggling," says Florida State University paleobiologist Greg Erickson, who is not on the team but saw the fish fossils firsthand when visiting DePalma's lab several weeks ago. "I've never seen anything like that, and there's stacks of these things!"

Seismic sloshing

Though DePalma and his colleagues interpret the site as an estuary in a river valley, there are signs of creatures at Tanis that normally lived out at sea. The study documents some fragmentary marine fossils, including the teeth of ancient sharks, aquatic reptiles called mosasaurs, and an extinct type of mollusk called an ammonite. DePalma and his teams interpret the mix of land and ocean animals as a sign that water from an inland sea suddenly washed upriver, spilling its guts onto the riverbanks at Tanis. ( See other evidence for a mass shark extinction in the wake of the asteroid strike.)

"The presence of the ammonite there is very weird ... it's like putting a squid in the Upper Potomac," says Kirk Johnson, director of the Smithsonian National Museum of Natural History and an expert on the Hell Creek Formation. Johnson adds that if the mosasaur tooth is confirmed to be the same age as the rest of the site, it could represent the youngest mosasaur material ever found.

The site's sediments also suggest that a sudden rush of water overtook it. Researchers initially thought the deluge was the impact's tsunami racing up the Western Interior Seaway, a dinosaur-era body of water that stretched from the Gulf of Mexico to northwest North America. But the timing was off: It would have taken eight to 16 hours for the tsunami to reach Tanis, but the site's sloshing must have occurred within the first hour after impact.

Instead, the team thinks that the floods were seiche waves, pulses of flooding caused by magnitude 10 to 11 earthquakes triggered by the impact. Much like the footfalls of T. rex shook every glass of water in the film Jurassic Park, the asteroid impact would have generated such waves that would have sloshed bodies of water around the world.

Extraordinary claims

So far, many geologists and paleontologists have welcomed the study's insights into the asteroid impact.

"The beauty of the study-and it is a beautiful piece of work-is that it is what you expect: Giant rock hits Earth, stuff happens," says Paul Renne, a geochronologist at the University of California, Berkeley, who has studied the detailed timing at the end of the Cretaceous.

However, nearly every paleontologist contacted by National Geographic who is not on the study team raised some concerns about the rollout of the discovery, going back to when DePalma presented previews at conferences in 2013 and 2016. Some researchers were so shocked by his claims at the time, they wondered whether the site was too good to be true.

Some of DePalma's early work has also raised eyebrows, including one high-profile error. In 2015, DePalma unveiled a new species of dinosaur called Dakotaraptor, but a follow-up study in 2016 revealed that DePalma had accidentally included fossil turtle bones in Dakotaraptor's reconstructed skeleton. Still, DePalma's colleagues vigorously defend his work on Tanis.

"There's not one person out there that hasn't dropped the ball at some point," Manning says. "He has produced a remarkable study."

Concerns also linger about the lack of visibility. The New Yorker story published days before the underlying scientific study and its 69-page supplement are set to formally appear online. National Geographic obtained both documents and distributed them to outside researchers for comment.

According to the New Yorker, Tanis abounds with fossils, including teeth, bones, and hatchling remains of almost every dinosaur group known from the Hell Creek Formation. The story also reports the presence of foot-long feathers possibly from dinosaurs, pterosaur remains, and an unhatched egg of some kind with a preserved embryo inside.

None of these details are in the study, however. No dinosaur bones are mentioned in the main study, and the supplement highlights only one hip-bone fragment from a horned dinosaur like Triceratops, found with "associated impressions of tissue." (The New Yorker claims that a suitcase-size piece of fossilized skin is attached to the bone fragment.)

"The weird thing is, DePalma has been very hyperbolic and cryptic for the last six years," says the Smithsonian's Johnson, who was also interviewed for the New Yorker story. "The paper is fine, and we can talk about its significance, [but we] have it paired with the New Yorker article, which has a lot more nuanced detail and a lot more claims. It just makes us all a little bit queasy."

Steve Brusatte, a paleontologist at the University of Edinburgh and a National Geographic grantee, also expresses some consternation: "Right now, I am left with more questions than answers ... It seems odd."

To verify the study's claims, paleontologists say that DePalma must broaden access to the site and its material.

"It's the case where extraordinary claims require extraordinary evidence; the jury should be out until other people look at this," says Kevin Padian, a paleontologist at the University of California, Berkeley.

DePalma says that the new study is supposed to be a geological introduction to Tanis, not a full description, and that the team is working on follow-up publications. Also, the excavated fossils are entering museum collections, making them available for wider study. The horned-dinosaur bone, for instance, now resides at Florida Atlantic University.

The researchers add that there are early discussions with the ranch owner on how best to protect Tanis for posterity. In the meantime, the site continues to reveal its secrets.

"Virtually every day they dig there, they see something they haven't seen before," says study coauthor Mark Richards, a geophysicist at the University of California, Berkeley, who visited the site in 2017. "You can go for days or months at a paleontology dig site and not find anything interesting, and [DePalma] finds things literally by the hour. It's unbelievable."

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Fossils may capture the day the dinosaurs died. Here's what you should know.

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Mere minutes after a miles-wide asteroid slammed into Earth 66 million years ago, a hailstorm of tiny glass beads rained down on a flooding estuary in what's now North Dakota. As seismic waves from the impact thrashed the water, plants and animals were jumbled up and buried in the shifting sediments, which preserved the aftermath for millennia.

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New Squid Genome Shines Light on Symbiotic Evolution

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New Squid Genome Shines Light on Symbiotic Evolution

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https://www.quantamagazine.org/new-squid-genome-shines-light-on-symbiotic-evolution-20190219/

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Black Hole at Center of Milky Way Galaxy

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Black Hole at Center of Milky Way Galaxy

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The Discovery of such a powerful force is truly groundbreaking research for science and may point to others being discovered with greater ease.

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Indication of Another Intermediate-mass Black Hole in the Galactic Center - IOPscience

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The American Astronomical Society (AAS), established in 1899 and based in Washington, DC, is the major organization of professional astronomers in North America. Its membership of about 7,000 individuals also includes physicists, mathematicians, geologists, engineers, and others whose research and educational interests lie within the broad spectrum of subjects comprising contemporary astronomy.

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Diverse microbes living in unique area.

https://www.sciencedaily.com/releases/2019/02/190227155805.htm
Nikki Nunes

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Interesting article about animal extinction and how we are experiencing the worst die off since the loss of dinosaurs.

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It’s an unprecedented extinction crisis — a million species facing extinction. Learn about our Saving Life on Earth campaign.

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Imagine a day when a bioprinter filled with a patient's own cells can be wheeled right to the bedside to treat large wounds or burns by printing skin, layer by layer, to begin the healing process. That day is not far off.

Wake Forest Institute for Regenerative Medicine (WFIRM) scientists have created such a mobile skin bioprinting system -- the first of its kind -- that allows bi-layered skin to be printed directly into a wound.

"The unique aspect of this technology is the mobility of the system and the ability to provide on-site management of extensive wounds by scanning and measuring them in order to deposit the cells directly where they are needed to create skin," said Sean Murphy, Ph.D., a WFIRM assistant professor who was lead author of the paper published this month in Nature's Scientific Reports journal.

Affecting millions of Americans, chronic, large or non-healing wounds such as diabetic pressure ulcers are especially costly because they often require multiple treatments. It is also estimated that burn injuries account for 10-30 percent of combat casualties in conventional warfare for military personnel.

The major skin cells -- dermal fibroblasts and epidermal keratinocytes -- are easily isolated from a small biopsy of uninjured tissue and expanded. Fibroblasts are cells that synthesize the extracellular matrix and collagen that play a critical role in wound healing while keratinocytes are the predominant cells found in the epidermis, the outermost layer of the skin.

The cells are mixed into a hydrogel and placed into the bioprinter. Integrated imaging technology involving a device that scans the wound, feeds the data into the software to tell the print heads which cells to deliver exactly where in the wound layer by layer. Doing so replicates and accelerates the formation of normal skin structure and function.

The researchers demonstrated proof-of-concept of the system by printing skin directly onto pre-clinical models.

The next step is to conduct a clinical trial in humans. Currently, skin grafts to treat wounds and burns are the "gold standard" technique, but adequate coverage of wounds is often a challenge particularly when there is limited availability of healthy skin to harvest. Skin grafts from donors are an option, but risk immune rejection of the graft and scar formation. With the WFIRM bioprinter system the researchers could see new skin forming outward from the center of the wound and this only happened when the patient's own cells were used, because the tissues were accepted and not rejected.

"The technology has the potential to eliminate the need for painful skin grafts that cause further disfigurement for patients suffering from large wounds or burns," said WFIRM Director Anthony Atala, M.D., and a co-author of the paper. "A mobile bioprinter that can provide on-site management of extensive wounds could help to accelerate the delivery of care and decrease costs for patients."

"If you deliver the patient's own cells, they do actively contribute to wound healing by organizing up front to start the healing process much faster," said James Yoo, M.D., Ph. D, who led the research team and co-authored the paper. "While there are other types of wound healing products available to treat wounds and help them close, those products don't actually contribute directly to the creation of skin."

Journal Reference:

Mohammed Albanna, Kyle W. Binder, Sean V. Murphy, Jaehyun Kim, Shadi A. Qasem, Weixin Zhao, Josh Tan, Idris B. El-Amin, Dennis D. Dice, Julie Marco, Jason Green, Tao Xu, Aleksander Skardal, James H. Holmes, John D. Jackson, Anthony Atala, James J. Yoo. In Situ Bioprinting of Autologous Skin Cells Accelerates Wound Healing of Extensive Excisional Full-Thickness Wounds. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-018-38366-w

Cite This Page:

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skin care; wounds and healing; skin cancer; medical topics; graphene; biochemistry; medical technology; solar energy

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Mobile bedside bioprinter can heal wounds

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Imagine a day when a bioprinter filled with a patient's own cells can be wheeled right to the bedside to treat large wounds or burns by printing skin, layer by layer, to begin the healing process. That day is not far off.

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Warmer waters are killing our fish. We need to start making huge changes to stop global warming before its too late.

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A new study published Thursday in the journal Science outlines the impacts warming waters are having on commercially important fish species.

The world's fishing industry relies on what's called fisheries, the clusters of regional fish populations that people can catch economically. And on average, the researchers found that the numbers of fish in critical fisheries around the world have decreased by four percent since 1930.

Fisheries located in the Sea of Japan and the North Sea were the worst off. They experienced as much as a 35 percent drop in their numbers. Other fisheries, however, benefitted from warmer waters, and their populations grew, an expansion scientists warn could create unsustainable competition for resources.

"We were surprised at the strength the impact of warming has already had on fish populations," says the study's lead author, ecologist Chris Free at the University of California Santa Barbara.

Taking the ocean's temperature

To measure the effect of warming and overfishing, Free started by looking at temperature data from the past 80 years and comparing it to how productive a given fishery was during periods of higher-than-average temperatures. The team looked at 235 populations of 124 species of fish spread across 38 different regions.

Warmer waters can make some fisheries smaller by putting metabolic stress on the fish, making it harder for them to reproduce or find food. Warm waters can also cause zooplankton, essential fish food, to decline. The impacts on smaller organisms then have cascading impacts on the rest of the food chain.

In the North Sea and the Sea of Japan where they measured increased water temperature, scientists found overfishing had further made the fisheries even more vulnerable.

"It's like a one-two punch," says study co-author Malin Pinsky, an ecologist at Rutgers. "If fishing already knocks them down, they're more likely to respond poorly when it's hot."

"When Chris brought me these figures, I was really stunned," Pinsky adds. "We knew that animals were moving into new locations, but I didn't realize it already affected the ability of these populations to produce fish."

Mitigating warming impacts

Fisheries ecologist Will White from Oregon State University was not involved with Free and Pinsky's study, but he says their conclusions highlight the importance of managing fisheries.

"With a lot of fisheries off the West Coast, we have historically had pretty good fishery management, which has given us resilience," says White.

From 2014 to 2016, the West Coast felt the deadly presence of a patch of warmer water called the "blob." When it warmed Pacific waters, it killed off marine creatures like zooplankton that salmon feed on, jeopardizing the health of Oregon's lucrative salmon fisheries.

"I'm not sure there's a way to manage our way out of that," White says of acute ocean warming, but on a less dramatic, global scale, he says taking warming oceans into consideration should be an important fishery management tool.

Pinsky cautions against viewing growing populations as a good sign.

"Fish are a bit like goldilocks," says Pinsky. "For some it's too cold, but warming will make it too hot."

Growing populations of one fish could also encroach upon the territory of another species. Off the coast of New England, populations of black sea bass have increased.

"Turns out," he adds, "they like to eat lobster. As they become more abundant, they may start impacting American lobster. There are all these ripple effects."

If current population trends continue at the same rate, the world will need to double its food production by 2050. To compensate, world leaders are consistently looking toward fisheries to be a critical source of protein for millions of people.

In 2016, 171 million tons of fish were taken from the sea, and that number is expected to rise to 201 million over the next 10 years.

"Food security is a big concern," says Pinsky. An estimated three billion people use fish as their primary source of protein.

"Beyond that," Pinsky adds, "we also know that it has very important local impacts for those who make their livelihoods catching these fish."

He thinks better management can help mitigate the impacts of warming. Establishing "no-take" zones, for instance, allow fish time to reproduce and regrow overfished populations.

Ultimately, Free says his study highlights the wide-ranging impacts of burning greenhouse gases. Unabated, he says some fisheries will likely continue their decline.

He adds, "We'll just have to be adaptive."

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Climate change is depleting our essential fisheries

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A new study published Thursday in the journal Science outlines the impacts warming waters are having on commercially important fish species. The world's fishing industry relies on what's called fisheries, the clusters of regional fish populations that people can catch economically.