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1. Why do people believe global warming is occurring on Earth?

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1. Why do people believe global warming is occurring on Earth?

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There is ice melting rapidly throughout the world. According to NASA, the planet's average surface temperature has risen about 1.62 degrees Fahrenheit since the late 19th century.

The main cause of this is the large increase of carbon dioxide and other human-made emissions.

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3. Where is the fastest warming of Earth's atmosphere occurring?

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3. Where is the fastest warming of Earth's atmosphere occurring?

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The Great Barrier Reef in Australia due to the coral mortality rate is above 50 percent.

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2. Why are some people skeptical of global warming?

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2. Why are some people skeptical of global warming?

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The rising sea levels may not have anything to do with climate change at all. Global sea level rise is simultaneously one of the most certain and uncertain impacts of climate change.

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4. Compare global population numbers with rising carbon dioxide levels. Are they related?

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4. Compare global population numbers with rising carbon dioxide levels. Are they related?

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"Population causes CO2. T The more people there are on our planet, the more CO2-generating activities there will be, such as electrical power generation, industrial activity, automobiles, cooking fires, etc."

"CO2 causes population. Population growth in these regions is dependent to a large extent on the food supply, and as we know, crop yields increase with CO2 levels. The greater the food supply, the longer people will live."

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Predictions of atmospheric CO2 levels at some future time are commonly made, usually with the object of assuring us that beyond a certain point our planet will be fried to a crisp. Most of these predictions are in the form 'if CO2 levels reach x, the effect will be such-and-such', without actually indicating why CO2 levels should reach such a value. However, it is possible to make an accurate prediction of future CO2 levels using readily available information.

The graph shown below plots CO2 levels as a function of world population, encompassing the period 1960 to 2015. Note that although each data point represents an individual year in sequential order, time is not explicitly represented on this graph, which merely shows how CO2 levels are related to overall world population.

It is reasonably obvious to the naked eye that CO2 and population seem to move in lockstep. To show this in more analytical terms, we can superimpose a trend line, which is simply a mathematical curve which fits the data. After some experimentation it was found that a trend line consisting of a third-order polynomial provided a very good fit to the data. In statistical terms, the R ² value for this curve is more than 0.999, which indicates that it correlates with the data to an accuracy of better than 99.9%.

One advantage of a trend line is that we can then extend it to make predictions of what the future may hold, which you can see in the chart below. Both axes in this chart have been extended for this purpose.

Of course, the same graph could have been drawn with CO2 levels on the horizontal axis and population on the vertical axis, so that population would be shown as the dependent variable and CO2 as the independent variable. The same correlation between the two would still exist.

The question that now arises is whether population is driving the CO2 level, or CO2 is driving population. There are four possibilities to be considered:

1. There is no connection between the two, the apparent lockstep is just a fluke. Possible, but very unlikely. This possibility can reasonably be ignored.

2. Population causes CO2. This is 'obvious' explanation that most people would give. The more people there are on our planet, the more CO2-generating activities there will be, such as electrical power generation, industrial activity, automobiles, cooking fires, and so on.

3. CO2 causes population. Much of the population growth in the foreseeable future will come from sub-Saharan Africa. Population growth in these regions is dependent to a large extent on the food supply, and as we know, crop yields increase with CO2 levels. The greater the food supply, the more children will survive to maturity.

4. The connection between CO2 and population results from some, as yet unspecified, combination of 2 and 3.

My personal view, and this is only an unsupported guess, is that possibility 4 is the most likely.

What conclusions can be drawn from this? First, the population/CO2 curve is a smooth curve. No evidence is shown of any significant decrease in the inexorable rise of either CO2 or population from beginning to end of this curve. We can conclude from this that none of the measures taken by industrialized countries to reduce CO2 output have had any noticeable effect, nor does it appear likely that they will have any significant effect in the foreseeable future.

Second, current UN population projections indicate that we will reach a population of 9 billion by 2038, and 10 billion by 2056, using the medium variant of their three prediction levels. (To follow this further, go to http://esa.un.org/unpd/wpp/Download/Standard/Population/, then download the spreadsheet called Total Population - Both Sexes.) Assuming that the population/CO2 relationship still holds good by then, we can predict a CO2 level of nearly 460 ppm by 2038 and 500 ppm by 2056.

Population growth is a quantity which can be reasonably well predicted for one or two decades into the future. While extrapolating a curve in order to make predictions is always fraught with danger, based on the data so far I am fairly confident that the CO2/population relationship will hold for a few years yet. In the long term of course, your guess is as good as mine, but I think we can reasonably well predict CO2 levels in the range 450-500 ppm by the middle of this century. Whether the world then disappears in a puff of smoke, or enters a new golden age of unsurpassed crop yields, remains to be seen.
Roger Graves is a physicist and mathematician who, much to his chagrin, is not associated with big oil, big coal, or big anything else.

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The correlation between global population and global CO2

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Guest essay by Roger Graves Predictions of atmospheric CO2 levels at some future time are commonly made, usually with the object of assuring us that beyond a certain point our planet will be fried to a crisp. Most of these predictions are in the form 'if CO2 levels reach x, the effect will be such-and-such', without...

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5. Are increasing levels of carbon dioxide in the atmosphere safe for humans?

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5. Are increasing levels of carbon dioxide in the atmosphere safe for humans?

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Breathing in too much of carbon dioxide may be life-threatening.

It can cause :

Suffocation by displacement of air

Unconsciousness

Inability to concentrate

Seizures

It can be released by:

volcanoes erupting

trees being cut down

fossil fuels

Products like oil and gas being burned.

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Carbon Dioxide: Your Environment, Your Health | National Library of Medicine

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Learn where carbon dioxide is found in our environment, how it is used, and the potential human health risks of exposure. Find out how to protect yourself, your family, and your community.

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6. What's an environmental refugee? What places will people flee from? Where will they go? 

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6. What's an environmental refugee? What places will people flee from? Where will they go? 

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Environmental refugees are a subset of environmental migrants who were forced to flee due to sudden changes to the environment and climate.

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Where will the climate refugees go? | Humanitarian Crises | Al Jazeera

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We use cookies and other tracking technologies to deliver and personalize content and ads, enable features, measure site performance, and enable social media sharing. You can choose to customize your preferences.Learn more about our Cookie Policy.

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7. In 50 years, would we be fleeing our area or accepting environmental refugees into our area?

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7. In 50 years, would we be fleeing our area or accepting environmental refugees into our area?

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Warmer global temperatures will play out differently in different regions of the world, but I think we will be accepting more refugees here because climate will change more in the northern and southern areas of the world.

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What kind of a climate we will experience in 2050 is something we, to a large degree, are actually in the process of deciding.

There are, of course, still some people who do not "believe" in human-caused climate change. Their reasons for this are usually justified by two arguments: The Earth's environment goes through natural cycles and humans cannot change those cycles. Indeed, variations on this line of reasoning are found daily in social media and other news outlets.

The first of these arguments is true--at least to a degree. The Earth's environment certainly has different states and, at various times in its history, the Earth has both been much colder and much warmer than it is today. In periods, the Earth's environment has also apparently "cycled" between different states, for example between ice and non-ice ages. On much shorter time scales, we see oscillations between El Niño and La Niña events.

However, the second argument is demonstrably wrong. Human activities are, without a doubt, influencing not only the global climate system but also several other global processes, which are important for establishing and maintaining the environment on Earth now and in the future.

It is this recognition of our ability to alter processes at the planetary level that causes many to refer to the current period of Earth history as the Anthropocene, meaning the "period of humankind". And knowing that we have the power to influence global climate is enormously important when we want to imagine what our climate might look like in 2050.
Read More: More extreme warm days in a warmer climate
Climate in 2050 largely depends on us

The famous quip "prediction is very difficult - especially about the future" is ever more appropriate when we want to predict future Earth conditions as the climate in 2050 will depend, to a very large degree, on decisions we make now and in the immediate future.

Climate is controlled by how much of the Sun's heat energy arrives at, and remains near, the Earth's surface. Scientists tell us that we can expect no major changes in heat arriving from the Sun for many thousands of years to come. So the changes we will see in climate from now until 2050 will mostly be related to how much of the arriving heat stays here.

This is where our greenhouse gas (GHG) waste ("emission") becomes important. The greater the concentration of these gases in the atmosphere, the more heat is retained near the Earth and the higher the global average temperature will be.
Read More: What makes the climate change? Part one
How hot could it get?

Global political leaders have agreed (the Paris Climate Agreement) that we, the global community, will reduce our GHG emissions to the point that human-caused global warming will never raise the average annual global air temperature by more than two degrees Celsius above those at the beginning of the Industrial Revolution. Even if the voluntary emission reduction goals announced by almost all countries at the signing of the Paris Agreement were to be met, however, human-caused global warming is estimated to reach around three degrees.

Of course, it is possible for countries and for all of us (!) to adopt even more ambitious goals. If we do so, then many scientists believe that it is still possible to keep global warming within two degrees. The chances of meeting this goal are, however, quickly waning--a recent scientific report suggests that there is only about a five per cent chance of restraining global warming to within two degrees.

Furthermore, if we really are to retain human-caused global warming to within 2 degrees, we need to act quickly. We can calculate approximately how much GHG we can release to the atmosphere and still maintain the human-caused global temperature increase to within 2 degrees. We call this our GHG "budget" and we are fast using that budget. Many argue that the absolute amount of GHG released per year must begin to decline within about 3 years in order to meet the 2 degree target.
Read More: COP21: What does two degrees Celsius global warming look like?
What if we do not meet the two degrees target?

But if the two degree target is not met, what then?

The Intergovernmental Panel on Climate Change (IPCC) applies a range of scenarios making different assumptions regarding the global community's ability to reduce GHG emissions to a collection of global climate models to project what global average temperatures might be in 2100. In some ways, it is a pity that the IPCC projections stop in 2100 as this might give the false impression that the effects of global warming will be fully felt by 2100. In fact, adjustments in the Earth system in response to the increased heat energy stored will go on for centuries. Ice, for example, will continue to melt and sea levels continue to rise well beyond 2100.

If we do no more than we are doing today to reduce GHG emissions, the IPCC projects that temperature in 2100 will be up to approximately five degrees higher than it is today. The model results generated when the different scenarios of emissions reduction are applied should not, however, be interpreted as predictions of future temperature at any given time or place but they do provide estimates of the approximate magnitude of emissions reduction necessary to restrain human-caused global warming to within different limits.
Read More: Seven tips to cut your CO2 emissions
Assessing the risk of temperature change

There is, of course, uncertainty associated with the IPCC temperature projections. We can use this uncertainty to tell us something about the risks we are facing if we continue our emissions. For example, even at today's greenhouse gas concentrations, the IPCC identifies a 1.6 percent chance that the Earth will warm by six degrees above the pre-Industrial level.

One-point-six per cent does not sound like much but, if we were to accept a 1.6 percent chance of airplanes crashing, we would accept approximately 1,500 airplanes crashing every day! What's more, modern humans have never experienced a five degree warmer world and, after hundreds of years, when the ice caps have melted, that much global warming would likely lead to a sea level rise of more than 40 metres.
Read More: Scientists: Three years left to reverse greenhouse gas emission trends
The Earth will still be warming in 2050

So, the Earth will be warmer in 2050 than it is today and it will still be warming. As noted above, it takes a long time for the Earth's system to adjust to the changes in its energy budget that increased GHG concentrations imply. That means that, even if we stopped all greenhouse gas emissions today, air temperature would continue to increase for decades.

How much warmer the Earth will be in 2050 is, then, to some extent up to us. Experience from recent years, in which air temperatures have steadily been increasing, has given us the contours of what warmer temperatures will mean for the climate we might expect in 2050.

Even if the goals of the Paris Climate Agreement are met, by 2050 we will globally be looking at heat waves that are dangerous for human health, changes in patterns of rainfall and snowfall, more intense storms, and changes in the distribution, and even extinctions, of various plants and animals--including human pathogens.
Clima​te Change Read More: Four big changes in the Arctic and what to do about them
Warming will be felt differently around the world

Crucially, warmer global temperatures will play out differently in different regions of the world.

For Africa, where populations are growing faster than anywhere else, they will mean increasingly large areas plagued by drought [and the potential mass migration of people no longer able to grow food locally and find water.

In Northern Europe, they will mean warmer winters but also more rain, an increasing number of cloudbursts, stronger storms, and changes in the nature around us. Some already wet agricultural lands will become too wet to farm and sea level will continue to rise.

Coastal regions will be eroded, washing buildings and other infrastructure out to sea and leading to higher insurance premiums.

That such changes will characterise the climate in 2050 is almost without doubt. The question is really only the degree of these changes, and that is something that we-ourselves-can decide.

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Read this article in Danish on Forskerzonen, part of Videnskab.dk.

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What will our climate look like in 2050?

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Knowing that we have the power to influence global climate is enormously important when trying to imagine what our climate might look like in 2050. To a large degree, it will depend on actions our leaders take now and in the immediate future.

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8. Does gasoline that cars need to operate and function contribute to Earth's greenhouse effect?

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8. Does gasoline that cars need to operate and function contribute to Earth's greenhouse effect?

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Materials like gasoline for our cars and burning gas, coal, oil for our homes release greenhouse gases. These include CO2, methane, and water vapor.

Heat gets trapped and the earth’s temperature rises when greenhouse gases build up. In order to decrease the amount of gases in the atmosphere, people can try to use less energy.

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Susan Gilbert brings to Kids Korner and its growing number of support materials her education and experience as an instructional designer and her enthusiasm for energy education. As president and co-founder of Apogee, Susan is the primary architect behind Apogee's online energy courses and web content divisions, effectively translating her nearly 25 years of energy efficiency and training experience into highly interactive, online training courseware and Web site tools.

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9. How does an increasing consumption of and demand for meat in a human's diet relate to carbon emissions?

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9. How does an increasing consumption of and demand for meat in a human's diet relate to carbon emissions?

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Meat can be obtained through different farmings, livestock production, agriculture hunting, and fishing.

All agricultural practices have been found to have a variety of effects on the environment. Some of the environmental effects that have been associated with meat production are pollution through fossil fuel usage, animal methane, effluent waste, and water and land consumption.

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10. How does an increasing consumption of and demand for fish in a human's diet relate to carbon emissions?

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10. How does an increasing consumption of and demand for fish in a human's diet relate to carbon emissions?

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Due to people littering, pollution has increased more than ever. The fish we eat are exposed to toxic chemicals in the bodies of waters they live in. Mercury has shown up at disturbingly high levels in many fish
Sometimes fish even get chemicals from the plastic debris they ingest.

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How Plastic In The Ocean Is Contaminating Your Seafood

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Fish can absorb toxic chemicals that have been dumped into waterways, but they can also get them from eating plastic. And there’s a lot of plastic in the open ocean, which scientists say can act like a sponge, soaking up the chemicals already out there.

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11. Find a graphic of human-influenced CO2 emissions and the atmospheric concentration of CO2. Do the graphs look like hockey sticks?

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11. Find a graphic of human-influenced CO2 emissions and the atmospheric concentration of CO2. Do the graphs look like hockey sticks?

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Yes, the graphs form a line similar to hockey sticks.

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12. What can ice cores tell us about the history of Earth's climate over time? How far back in time can ice cores provide info?

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12. What can ice cores tell us about the history of Earth's climate over time? How far back in time can ice cores provide info?

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They allow us to go back in time to sample accumulation, air temperature and air chemistry.
Ice core records allow us to generate continuous reconstructions of past climate, going back at least 800,000 years.
Scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past and compare past concentrations of greenhouse gasses to temperature.

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1. Jouzel, J. and V. Masson-Delmotte, 2010. Deep ice cores: the need for going back in time. Quaternary Science Reviews, 29(27): 3683-3689.

2. Augustin, L., C. Barbante, P.R.F. Barnes, J.M. Barnola, M. Bigler, E. Castellano, O. Cattani, J. Chappellaz, D. DahlJensen, B. Delmonte, G. Dreyfus, G. Durand, S. Falourd, H. Fischer, J. Fluckiger, M.E. Hansson, P. Huybrechts, R. Jugie, S.J. Johnsen, J. Jouzel, P. Kaufmann, J. Kipfstuhl, F. Lambert, V.Y. Lipenkov, G.V.C. Littot, A. Longinelli, R. Lorrain, V. Maggi, V. Masson-Delmotte, H. Miller, R. Mulvaney, J. Oerlemans, H. Oerter, G. Orombelli, F. Parrenin, D.A. Peel, J.R. Petit, D. Raynaud, C. Ritz, U. Ruth, J. Schwander, U. Siegenthaler, R. Souchez, B. Stauffer, J.P. Steffensen, B. Stenni, T.F. Stocker, I.E. Tabacco, R. Udisti, R.S.W. van de Wal, M. van den Broeke, J. Weiss, F. Wilhelms, J.G. Winther, E.W. Wolff, M. Zucchelli, and E.C. Members, 2004. Eight glacial cycles from an Antarctic ice core. Nature, 429(6992): 623-628.

3. Johnsen, S.J., D. Dahl-Jensen, N. Gundestrup, J.P. Steffensen, H.B. Clausen, H. Miller, V. Masson-Delmotte, A.E. Sveinbjornsdottir, and J. White, 2001. Oxygen isotope and palaeotemperature records from six Greenland ice-core stations: Camp Century, Dye-3, GRIP, GISP2, Renland, and NorthGRIP. Journal of Quaternary Science, 16: 299-307.

4. Mulvaney, R., N.J. Abram, R.C.A. Hindmarsh, C. Arrowsmith, L. Fleet, J. Triest, L.C. Sime, O. Alemany, and S. Foord, 2012. Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history. Nature, 489: 141-144.

5. Lambert, F., B. Delmonte, J.-R. Petit, M. Bigler, P.R. Kaufmann, M.A. Hutterli, T.F. Stocker, U. Ruth, J.r.P. Steffensen, and V. Maggi, 2008. Dust-climate couplings over the past 800,000 years from the EPICA Dome C ice core. Nature, 452(7187): 616-619.

6. Brook, E.J., ICE CORE METHODS | Overview, in Encyclopedia of Quaternary Science, A.E. Scott, Editor. 2007, Elsevier: Oxford. 1145-1156.

7. Aciego, S., B. Bourdon, J. Schwander, H. Baur, and A. Forieri, 2011. Toward a radiometric ice clock: uranium ages of the Dome C ice core. Quaternary Science Reviews, 30(19): 2389-2397.

8. Abram, N.J., R. Mulvaney, E.W. Wolff, J. Triest, S. Kipfstuhl, L.D. Trusel, F. Vimeux, L. Fleet, and C. Arrowsmith, 2013. Acceleration of snow melt in an Antarctic Peninsula ice core during the twentieth century. Nature Geosci, advance online publication.

9. Jouzel, J. and V. Masson-Delmotte, ICE CORE RECORDS | Antarctic Stable Isotopes, in Encyclopedia of Quaternary Science, A.E. Scott, Editor. 2007, Elsevier: Oxford. 1242-1250.

10. Bertler, N.A.N., P.A. Mayewski, and L. Carter, 2011. Cold conditions in Antarctica during the Little Ice Age - implications for abrupt climate change mechanisms. Earth and Planetary Science Letters, 308: 41-51.

11. Grachev, A.M., ICE CORE RECORDS | Thermal Diffusion Paleotemperature Records, in Encyclopedia of Quaternary Science, A.E. Scott, Editor. 2007, Elsevier: Oxford. 1280-1284.

12. Abbott, P.M. and S.M. Davies, 2012. Volcanism and the Greenland ice-cores: the tephra record. Earth-Science Reviews, 115(3): 173-191.

13. Hoek, W., Z. Yu, and J.J. Lowe, 2008. INTegration of Ice-core, MArine, and TErrestrial records (INTIMATE): refining the record of the Last Glacial - Interglacial Transition. Quaternary Science Reviews, 27(1): 1-5.

14. Abram, N.J., E.W. Wolff, and M.A.J. Curran, 2013. A review of sea ice proxy information from polar ice cores. Quaternary Science Reviews, 79(0): 168-183.

15. Fischer, H., F. Fundel, U. Ruth, B. Twarloh, A. Wegner, R. Udisti, S. Becagli, E. Castellano, A. Morganti, and M. Severi, 2007. Reconstruction of millennial changes in dust emission, transport and regional sea ice coverage using the deep EPICA ice cores from the Atlantic and Indian Ocean sector of Antarctica. Earth and Planetary Science Letters, 260(1): 340-354.

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1. Jouzel, J. and V. Masson-Delmotte, 2010. Deep ice cores: the need for going back in time. Quaternary Science Reviews, 29(27): 3683-3689. 2. Augustin, L., C. Barbante, P.R.F. Barnes, J.M. Barnola, M. Bigler, E. Castellano, O. Cattani, J. Chappellaz, D. DahlJensen, B. Delmonte, G. Dreyfus, G. Durand, S. Falourd, H.

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13. How have sea levels fluctuated over the last thousand years? Is this driven by natural circumstances or is this caused by humans?

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13. How have sea levels fluctuated over the last thousand years? Is this driven by natural circumstances or is this caused by humans?

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"Between 1900 and 1990 studies show that sea level rose between 1.2mm and 1.7mm per year on average. By 2000, that rate had increased to about 3.2mm per year. Sea levels are expected to rise even more quickly by the end of the century."

Scientists have said how sea levels have increased over time mainly due to climate change. They also agree that changes in climate are mainly caused by humans and their activities.

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14. If the glaciers melt, where does most of the liquid go? Is ocean water drinkable? Can it be used to irrigate crops for 7 billion Earthlings?

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14. If the glaciers melt, where does most of the liquid go? Is ocean water drinkable? Can it be used to irrigate crops for 7 billion Earthlings?

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According to ScientificAmerican.com,  "Less moisture is trapped in ice sheets, so more is found in liquid form.
When ice pieces fall off landmasses, such as Antarctica or Greenland, and into the ocean, the ice melts even faster."

According to water.usgs.gov, "Seawater is toxic because your body fails eventually when it has to try to get rid of the salt that comes from sea water. Your body normally gets rid of excess salt by having the kidneys produce urine, but it needs freshwater to dilute the salt in your body for the kidneys to work properly."

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15. What is ocean acidification? How has it influenced our oceans over the last 100 years?

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15. What is ocean acidification? How has it influenced our oceans over the last 100 years?

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Ocean acidification is cause by the increasing amount of carbon dioxides in oceans. It has greatly influenced oceans due to   it becoming more difficult for animals to build their homes, like coral reefs and could kill organisms like plankton, which would also affect animals like fish and whales.

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Our continued burning of fossil fuels is increasing the levels of carbon dioxide in the atmosphere. Most of the carbon dioxide that is released into the atmosphere ultimately ends up in the oceans.

Consequently, the oceans have been absorbing large amounts of carbon dioxide since the Industrial Revolution (approximately 1750). It is this increasing amount of carbon dioxide in the oceans that is causing ocean acidification.

When carbon dioxide enters the ocean, it combines with seawater to produce carbonic acid, which increases the acidity of the water, lowering its pH. Although it is unlikely that the ocean will ever become actual acid (fall below a pH of 7.0), the term acidification refers to the process of the oceans becoming more acidic.

A consequence of the oceans becoming more acidic is the binding up of carbonate ions, which are used by marine creatures to make their calcium carbonate shells and skeletons. As the availability of carbonate ions decreases, it becomes more difficult for these animals to build their calcium carbonate structures. Imagine trying to build a house while someone keeps stealing your bricks.

As the oceans become more acidic, it will become progressively more difficult, if not impossible, to build calcium carbonate shells and skeletons. By the middle to end of this century, parts of the oceans will be corrosive enough that they will cause already formed calcium carbonate to dissolve.

The pH of the ocean surface has already fallen 0.1 units, representing a 30 percent increase in acidity. By the end of this century, if current emission trends continue, it could fall by another 0.3 units, thereby increasing the acidity of the oceans by almost 2.5 times. The pH scale can be misleading because it is logarithmic, so its units may seem incremental, when in fact, they represent major changes in acidity.

For example, a seemingly small drop of 0.4 units in pH actually represents more than a doubling (an almost 150 percent increase) in the acidity of the ocean. In the last 300 million years or more, ocean pH has never fallen to more than 0.6 units below the level of 1750. However, if fossil fuel use continues unabated over the next couple of centuries, ocean pH could fall more than 0.7 units below the 1750 level.

The current concentration of carbon dioxide in the atmosphere is much higher than it has been at any time over the course of human civilization. In fact, as far back as scientists have currently determined (800,000 years), the natural range has not exceeded 300 ppm. If we continue on our current emissions trajectory, by 2050 ocean pH will be lower than at any point in the last 20 million years.

Even more significant is the rate at which ocean chemistry is changing. The current rate of acidification is at least 100 times faster than any time period over the last few hundred thousands years and is it most likely unprecedented in Earth's history. Carbon dioxide is being absorbed so rapidly that it is likely that many marine organisms will not be able to adapt to the quickly changing conditions.

One of the major concerns is that the most vulnerable species to ocean acidification are also some of the most important for healthy marine ecosystems. Ocean acidification may adversely impact some plankton species, and their loss would ripple through food webs to impact larger animals like fish and whales.

Corals are also very susceptible to the impacts of ocean acidification and coral reefs are some of the most beautiful and biologically diverse habitats on the planet. Ocean acidification has the potential to cause widespread changes in marine ecosystems which may eventually disrupt the ocean goods and services we depend on. If nothing is done to help curb ocean acidification, its negative impacts may be felt on the marine environment, local communities, and all the way up through the global economy

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Our continued burning of fossil fuels is increasing the levels of carbon dioxide in the atmosphere. Most of the carbon dioxide that is released into the atmosphere ultimately ends up in the oceans. Consequently, the oceans have been absorbing large amounts of carbon dioxide since the Industrial Revolution (approximately 1750).

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16. What are sea surface temps? Are SSTs too hot, too cold, or just right?

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16. What are sea surface temps? Are SSTs too hot, too cold, or just right?

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SST is a measure of the energy of the motion of molecules at the top layer of the ocean.

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17. Why is there less heat escaping into space?

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17. Why is there less heat escaping into space?

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The surface of the Earth is absorbing most of the sun's heat, but it gives infrared radiation to space.

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22. CO2 has been associated with the Warming of Earth. CO2  is taken out of the air by plants and trees through photosynthesis and replaced with breathable oxygen. 

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22. CO2 has been associated with the Warming of Earth. CO2  is taken out of the air by plants and trees through photosynthesis and replaced with breathable oxygen. 

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I think that it does not support them because of CO2 is the cause of it is mainly human activity, such as cutting down trees, littering, and industrialization.

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19. Clouds (water vapor) are considered a greenhouse gas. How can cloud coverage both complicate the heating of Earth and also help alleviate the heating of Earth?

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19. Clouds (water vapor) are considered a greenhouse gas. How can cloud coverage both complicate the heating of Earth and also help alleviate the heating of Earth?

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Clouds cool the Earth by reflecting incoming sunlight. The tiny drops or ice particles in clouds scatter between 20 and 90 percent of the sunlight that strikes them.

Clouds warm the Earth by absorbing infrared radiation emitted from the surface and reradiating it back down. The process traps heat like a blanket and slows the rate at which the surface can cool.

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If the cooling effect of clouds increases more than the heating effect does, the clouds would reduce the magnitude of the greenhouse-induced warming but speed its arrival (negative feedback). The same result could come about if both effects decrease, but the cooling decreases less than the heating does.

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18. How does CO2 trap infrared radiation on Earth?

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18. How does CO2 trap infrared radiation on Earth?

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CO₂ molecules vibrate in ways that simpler nitrogen and oxygen molecules cannot, which allows CO₂ molecules to capture the IR photons. Greenhouse gases and the greenhouse effect play an important role in Earth's climate.

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Molecules of carbon dioxide (CO₂) can absorb energy from infrared (IR) radiation. This animation shows a molecule of CO ₂ absorbing an incoming infrared photon (yellow arrows). The energy from the photon causes the CO ₂ molecule to vibrate. Some time later, the molecule gives up this extra energy by emitting another infrared photon. Once the extra energy has been removed by the emitted photon, the carbon dioxide molecule stops vibrating.

This animation is somewhat of a simplification. Molecules are constantly in motion, colliding with other gas molecules and transferring energy from one molecule to another during collisions. In the more-complex, real-world process, a CO ₂ molecule would most likely bump into several other gas molecules before re-emitting the infrared photon. The CO ₂ molecule might transfer the energy it gained from the absorbed photon to another molecule, adding speed to that molecule's motion. Since the temperature of a gas is a measure of the speed of the molecules in the gas, the faster motion of a molecule that eventually results from the IR photon that was absorbed by a CO ₂ molecule raises the temperature of the gases in the atmosphere.

Do all gas molecules absorb and re-emit infrared energy?

This ability to absorb and re-emit infrared energy is what makes CO ₂ an effective heat-trapping greenhouse gas. Not all gas molecules are able to absorb IR radiation. For example, nitrogen (N ₂) and oxygen (O ₂), which make up more than 90% of Earth's atmosphere, do not absorb infrared photons. CO ₂ molecules can vibrate in ways that simpler nitrogen and oxygen molecules cannot, which allows CO ₂ molecules to capture the IR photons.

Greenhouse gases and the greenhouse effect play an important role in Earth's climate. Without greenhouse gases, our planet would be a frozen ball of ice. In recent years, however, excess emissions of carbon dioxide and other greenhouse gases from human activities (mostly burning fossil fuels) have begun to warm Earth's climate at a problematic rate. Other significant greenhouse gases include water vapor (H ₂O), methane (CH ₄), nitrous oxide (N ₂O) and ozone (O ₃).

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Carbon Dioxide Absorbs and Re-emits Infrared Radiation

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Molecules of carbon dioxide (CO2) can absorb energy from infrared (IR) radiation. This animation shows a molecule of CO 2 absorbing an incoming infrared photon (yellow arrows). The energy from the photon causes the CO 2 molecule to vibrate. Some time later, the molecule gives up this extra energy by emitting another infrared photon.

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21. How would you characterize the weather patterns of the U.S. in the last decade?

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21. How would you characterize the weather patterns of the U.S. in the last decade?

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"The past decade has been one of unprecedented weather extremes. For extreme rainfall and heat waves the link with human-caused global warming is clear, the scientists show in a new analysis of scientific evidence.

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The past decade has been one of unprecedented weather extremes. Scientists of the Potsdam Institute for Climate Impact Research (PIK) in Germany argue that the high incidence of extremes is not merely accidental. From the many single events a pattern emerges. At least for extreme rainfall and heat waves the link with human-caused global warming is clear, the scientists show in a new analysis of scientific evidence in the journal Nature Climate Change. Less clear is the link between warming and storms, despite the observed increase in the intensity of hurricanes.

In 2011 alone, the US was hit by 14 extreme weather events which caused damages exceeding one billion dollars each -- in several states the months of January to October were the wettest ever recorded. Japan also registered record rainfalls, while the Yangtze river basin in China suffered a record drought. Similar record-breaking events occurred also in previous years. In 2010, Western Russia experienced the hottest summer in centuries, while in Pakistan and Australia record-breaking amounts of rain fell. 2003 saw Europe´s hottest summer in at least half a millennium. And in 2002, the weather station of Zinnwald-Georgenfeld measured more rain in one day than ever before recorded anywhere in Germany -- what followed was the worst flooding of the Elbe river for centuries.
A question of probabilities
"The question is whether these weather extremes are coincidental or a result of climate change," says Dim Coumou, lead author of the article. "Global warming can generally not be proven to cause individual extreme events -- but in the sum of events the link to climate change becomes clear." This is what his analysis of data and published studies shows. "It is not a question of yes or no, but a question of probabilities," Coumou explains. The recent high incidence of weather records is no longer normal, he says.

"It´s like a game with loaded dice," says Coumou. "A six can appear every now and then, and you never know when it happens. But now it appears much more often, because we have changed the dice." The past week illustrates this: between March 13th and 19th alone, historical heat records were exceeded in more than a thousand places in North America.
Three pillars: basic physics, statistical analysis and computer simulations
The scientists base their analysis on three pillars: basic physics, statistical analysis and computer simulations. Elementary physical principles already suggest that a warming of the atmosphere leads to more extremes. For example, warm air can hold more moisture until it rains out. Secondly, clear statistical trends can be found in temperature and precipitation data, the scientists explain. And thirdly, detailed computer simulations also confirm the relation between warming and records in both temperature and precipitation.

With warmer ocean temperatures, tropical storms -- called typhoons or hurricanes, depending on the region -- should increase in intensity but not in number, according to the current state of knowledge. In the past decade, several record-breaking storms occurred, for example hurricane Wilma in 2004. But the dependencies are complex and not yet fully understood. The observed strong increase in the intensity of tropical storms in the North Atlantic between 1980 and 2005, for example, could be caused not just by surface warming but by a cooling of the upper atmosphere. Furthermore, there are questions about the precision and reliability of historic storm data.

Overall, cold extremes decrease with global warming, the scientists found. But this does not compensate for the increase in heat extremes.
Climatic warming can turn an extreme event into a record-breaking event
"Single weather extremes are often related to regional processes, like a blocking high pressure system or natural phenomena like El Niño," says Stefan Rahmstorf, co-author of the article and chair of the Earth System Analysis department at PIK. "These are complex processes that we are investigating further. But now these processes unfold against the background of climatic warming. That can turn an extreme event into a record-breaking event."

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global warming; weather; climate; environmental issues; severe weather; storms; hurricanes and cyclones; environmental awareness

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Extreme weather of last decade part of larger pattern linked to global warming

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The past decade has been one of unprecedented weather extremes. Scientists now argue that the high incidence of extremes is not merely accidental. From the many single events a pattern emerges. At least for extreme rainfall and heat waves the link with human-caused global warming is clear, the scientists show in a new analysis of scientific evidence.

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23. Droughts and forest fires are on the rise all around the world. If there's no water for the plants to drink and survive, how can they effectively remove CO2 from the atmosphere?

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23. Droughts and forest fires are on the rise all around the world. If there's no water for the plants to drink and survive, how can they effectively remove CO2 from the atmosphere?

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In order to completely remove CO2 is far from simple, but ways to reduce it include:
- planting more forests
- crushing more rocks
-burning plants for energy
-sprinkling iron in the ocean

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Climate Fwd:

Welcome to the Climate Fwd: newsletter. The New York Times climate team emails readers once a week with stories and insights about climate change. Sign up here to get it in your inbox.
This week: Are we ready to remove carbon dioxide from the air? Would drone deliveries help or hurt the environment? And will Canada push the United States on climate change?

Image

Credit Claire O'Neill/The New York Times

Do you have questions about climate change? We're answering them in this newsletter. Send us yours via the form at the bottom of our climate Q. and A. This one was sent to us from Walter Beinecke in Manchester-by-the-Sea, Mass.:
What are the leading/viable technologies to remove carbon dioxide from the atmosphere?
Removing carbon dioxide that is already in the air is seen as a potential way to combat global warming. There are various approaches, lumped together as "negative emissions technologies" to distinguish them from technologies that reduce or eliminate emissions from power plants and other sources.

In theory, reducing the concentration of heat-trapping carbon dioxide in the atmosphere might be one way to keep the world under the two-degree Celsius target for warming established by the 2015 Paris climate agreement. But in practice, removing carbon dioxide is far from simple. There are major questions about scale, cost, speed and energy requirements. In most cases, the carbon dioxide that was removed would have to be buried underground indefinitely - and carbon storage technologies have only been deployed on a small scale so far.

Some removal technologies are more fanciful than others, but as for which are most viable, it could be argued that none are, at least not yet. In a report last month, the European Academies Science Advisory Council offered a pessimistic outlook for carbon removal, saying that it offered only "limited realistic potential" to have a climate impact. The authors argued that the world should not count on removal technologies to make up for a failure to sharply reduce or eliminate emissions in the first place.

There are five major approaches to carbon dioxide removal:

Plant more forests. Trees remove carbon dioxide naturally, incorporating it into their tissues as they grow. Worldwide, forests store about one billion to two billion tons of carbon annually, offsetting a chunk of the roughly 10 billion tons emitted by human activity. Reforestation and afforestation, properly managed, could remove a lot more and keep it out of the atmosphere. But planting forests is slow work - as Icelanders know well - and requires a lot of land. The world is currently much better at cutting down forests than planting new ones.

Crush a lot of rock. This technique is called enhanced weathering, and is based on the fact that some types of rock weather by naturally combining with carbon dioxide in the air or water. One suggested approach would use the mineral olivine, which is plentiful, crushing it into fine sand and spreading it on land, perhaps along coastlines. But mining, crushing and transporting the billions of tons needed would be expensive and energy intensive. And the carbon removal would still be exceedingly slow.

Burn plants for energy and capture the carbon dioxide. In this high-tech approach, called bioenergy with carbon capture and storage, or BECCS, vegetation would be used to naturally remove carbon dioxide. The vegetation would then be burned in a power plant and the carbon dioxide in the exhaust gases would be captured and stored. So far there are only a handful of working BECCS projects; others have been canceled. Among the many questions about the technology is whether emissions are really negative if the carbon cost of growing and harvesting the vegetation is taken into account.

Sprinkle iron in the ocean. Like enhanced weathering, fertilizing the ocean by putting iron particles or other nutrients in the water is among the more far-fetched approaches. The idea is that the nutrients would stimulate the growth of tiny marine plants called phytoplankton, which would incorporate carbon dioxide as they grew and then sink to the bottom of the ocean when they died, taking the carbon with them. Generally, however, putting large amounts of metal or chemicals into seawater is considered ocean dumping. There have been only a few tests of the idea, one of which was conducted without scientific oversight off Western Canada in 2012 under the pretense of helping a native Canadian community improve its salmon catch.

Suck carbon dioxide out of the air. There has been a significant amount of research into "direct air capture." Much of the technology is similar to what is used in carbon capture projects at power plants: chemicals bind with carbon dioxide molecules and then are heated or otherwise treated to release them for capture. Several companies, including Carbon Engineering and Climeworks, have developed machines to do this. But carbon capture at a fossil-fuel plant, where carbon dioxide can make up perhaps 5 to 10 percent of the exhaust gases, is one thing. Doing it from the air is another. For all the rightful concern about rising carbon dioxide levels, the gas still makes up only about 0.04 percent of the atmosphere. Removing a significant amount of it would involve moving huge volumes of air through thousands upon thousands of capture machines, and powering the machines for decades.

A drone flew over Amazon's testing site in Cambridgeshire, England, in 2016. Credit Andrew Testa for The New York Times

On Dec. 7, 2016, an Amazon Prime Air drone flew 13 minutes from a warehouse in Cambridgeshire, England, to a customer's home a couple of miles away, where it delivered an Amazon streaming device and a bag of popcorn. The flight was among the first attempts in the race to make drone delivery a reality, which has also attracted companies like Alphabet and U.P.S. Even before Amazon's inaugural flight, 7-Eleven had already dispatched doughnuts in Reno, Nev., and Domino's landed chicken pizzas near Auckland, New Zealand.

In a study published this year in Nature Communications, researchers compared the potential environmental impacts of these pilotless couriers with those of existing ground delivery systems. They found that small drones designed to carry packages weighing about a pound or less had a smaller carbon footprint per delivery than diesel and even electric trucks. But bigger drones carrying packages of up to 18 pounds were likely to generate more planet-warming emissions over all.

"My first impression was that if you were really going to do this, it would be a terrible idea for the environment," said Joshuah Stolaroff, an environmental scientist at Lawrence Livermore National Laboratory in California and the lead author of the study. "So I was somewhat surprised that the results were mixed the way they were," he said. "There are opportunities for drones to save energy and emissions."

While drones could consume less energy per package than diesel-powered delivery trucks, additional warehouses would be needed to service those drones, negating at least some of the environmental benefits. To blanket the San Francisco Bay Area, for example, researchers estimated that 112 warehouses and way stations would be needed to house products and drones. Those spaces would need to be cooled and heated, releasing further emissions.

"If you want to properly consider the impacts of drones, you have to consider the whole life cycle," Dr. Stolaroff said.

(The study did not assess ideas like trucks that launch drones or flying drone warehouses, but the researchers said they would consider those types of scenarios in future work.)

In every scenario, however, researchers found that getting something delivered by a drone would be better for the environment than driving to a store to pick it up yourself. "Taking your whole two-ton steel vehicle four miles round trip to get an item is way worse," unless you can complete multiple errands on the same trip, Dr. Stolaroff said.

While drone delivery has yet to be rolled out on a mass scale, Amazon said in a statement that it was committed to offering a delivery option that would "benefit both customers and the planet."

"With drone delivery," Dr. Stolaroff said, "we have an opportunity that we don't usually have with new technology, which is to consider their impacts before they are widely deployed."

Catherine McKenna, Canada's environment minister. Credit Max Rossi/Reuters

Catherine McKenna, Canada's environment minister, was in New York last week to discuss ocean health and climate change with city officials and business leaders. We had a chance to talk about the Group of 7 meeting of leaders of major industrialized nations, to be held in Charlevoix, Quebec, in June.

Last year in Italy the Group of 7 meeting was a flash point on climate change. The Trump administration refused to join the other six nations in reaffirming a commitment to reducing greenhouse gas emissions through the Paris agreement. Ms. McKenna told me she hopes to avoid another such split with the United States, but she said her country won't back down on its commitment to the accord. Here's a portion of our interview, edited and condensed for clarity.
How big a deal is climate change going to be at the G-7?
Climate change, oceans and energy are our top priorities. It is really important. We understand that you need to keep the momentum on climate action. Oceans are a real focus for the prime minister. He really is looking for something along the lines of a zero-waste charter. And I think there's a lot of momentum with that. We've had good discussions with the U.S. There's interest in doing something on plastics. We know that we may have more plastic than fish in the ocean by 2050, which is a really sad state for the ocean.
Are you actively looking for environmental areas that are not climate change where you can find some common ground with the Trump administration?

I think plastics is certainly one where we need to be doing a lot more, and there is some appetite in the United States. Look, clearly in Canada climate change is a top priority. I'm the first minister of energy and climate change, and we've been very active domestically and internationally, so we're not going to shy away from that.
Last year the G-7 negotiations were quite antagonistic on climate change. Do you anticipate the same dynamic?
I'm certainly hopeful not. We certainly learned some lessons there.
Will Canada insist on affirming the Paris agreement in a Group of 7 joint statement?
Spending all your time negotiating a communiqué as opposed to just moving forward and talking about action is probably not where you necessarily want to be. I'm more interested in how we get serious action. Climate change is the biggest issue we face and we're going to continue having conversations about it. I'm always hopeful.
We'd love your feedback on this newsletter. Please email thoughts and suggestions to If you like what we're doing, please spread the word and send this to your friends. You can And be sure to check out our full assortment of free newsletters from The Times. sign up here to get our newsletter delivered to your inbox each week. climateteam@nytimes.com.

Livia Albeck-Ripka is a freelance journalist based in New York and Melbourne, Australia. @livia_ar

Henry Fountain covers climate change, with a focus on the innovations that will be needed to overcome it. He is the author of "The Great Quake," a book about the 1964 Alaskan earthquake. @henryfountain * Facebook

Lisa Friedman reports on climate and environmental policy in Washington. A former editor at Climatewire, she has covered nine international climate talks. @LFFriedman

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Can We Really Scrub Carbon Dioxide From the Atmosphere?

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Climate Fwd: Welcome to the Climate Fwd: newsletter. The New York Times climate team emails readers once a week with stories and insights about climate change. Sign up here to get it in your inbox. This week: Are we ready to remove carbon dioxide from the air?

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20. How do El Nino weather patterns influence climate?

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20. How do El Nino weather patterns influence climate?

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During El Niño events, warmer surface waters in the tropical Pacific move eastward because of winds. The temp of the waters in the western Pacific becomes cooler than normal, which leads to higher pressure and decreased rainfall there.

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El Niño Southern Oscillation, or ENSO, involves large-scale patterns of pressure, temperature, precipitation and winds that affect weather and climate over both the tropics and, through teleconnections, regions outside of the tropics. For an introduction to the science of ENSO, see our ENSO Essentials page.

Scientists have shown that the occurrence of floods, droughts and other climate-related disasters is not statistically different among years with El Niño, neutral or La Niña conditions (see Figure 1). So why does the El Niño-Southern Oscillation, or ENSO, matter? The short answer: in years with El Niño or La Niña conditions, such disasters may be more predictable, allowing decision makers to take action and prepare for such events. Since El Niño and La Niña events can persist up to or more than a year, their effects on temperature and precipitation patterns can last over many seasons and lead to accumulating societal effects.

How does ENSO affect climate and weather patterns?

The most direct effects of ENSO on regional climate patterns are found in those areas closest to the tropical Pacific. During neutral conditions, Indonesia and other areas in the western Pacific experience more precipitation than in the eastern Pacific, such as Peru and Ecuador. However, during El Niño events, warmer surface waters in the tropical Pacific move eastward because of slackened trade winds. This leads to areas of low pressure and increased rainfall along the west coasts of North and South America. Conversely, the temperature of the waters in the western Pacific become cooler than normal, which leads to higher pressure and decreased rainfall there. Although many regions of the world can experience disasters in any year, certain locations tend to be particularly hard hit during El Nino events. For example, effects from past El Niño events include flooding and landslides in Peru and California (the 1997 El Niño caused $2 billion in property damages in Peru); forest fires and their ensuing air pollution in Indonesia; and droughts in northern Australia.

During neutral and La Niña conditions, the upwelling of cold and nutrient-rich water from the deep Pacific feeds and cultivates fisheries in coastal equatorial South America. When El Niño conditions occur, warmer water off of equatorial South America and weaker trade winds dampen the usual upwelling, reducing the amount of available nutrients. The lack of nutrients affects marine life throughout the food chain, resulting in severe impacts to the Peruvian fisheries. In 1972, due to a combination of overfishing and El Niño, Peruvian anchoveta fisheries collapsed. The 1997-98 El Niño also adversely affected the Peruvian fisheries and economy.

During La Niña events, the trade winds resume and intensify, which increases the equatorial upwelling and extends the colder water of the east Pacific westward. The resulting effects are essentially the reverse of El Niño: the western Pacific experiences higher than average precipitation, and the flooding that results can be severe if it follows extended drought brought on by El Niño. Lower than average temperature and rainfall occurs along the western coast of the Americas, while Northern Australia can experience more frequent tropical cyclones.

Can ENSO affect places far from the Pacific Ocean?

Yes! Although the strongest signal of ENSO impacts is in the areas closest to the equatorial Pacific, El Niño and La Niña are such powerful forces that they can shift seasonal temperature and precipitation patterns around the globe. These shifts, known as teleconnections, occur via the effects of tropical sea-surface temperatures on the upper atmosphere. When different parts of the tropical ocean warm and cool and the pressure gradients shift, the atmospheric wind patterns also shift to alter precipitation patterns. Strong tropical rainfall releases significant heat in the atmosphere, which can influence large-scale atmospheric circulation. The shift in location and intensity of tropical rainfall patterns results in shifts in the location and intensity of the jet stream and storm tracks, tropical cyclones and more. Because each El Niño and La Niña event has unique characteristics of timing, intensity and specific pattern changes, such shifts are never exactly the same during every El Niño and La Niña event. In addition, the atmospheric effects due to changes in sea-surface temperatures are responsible for only part of the regional climate observed; chaotic fluctuations within the atmosphere and sea surface temperatures in other areas of the globe also influence the weather and climate we experience. Because of this, anticipated ENSO impacts in seasonal forecasts are treated probabilistically and not with absolute certainty.

During the two strongest El Niño events of the twentieth century (1982-1983 and 1997-1998), the global impacts of altered climate patterns extended to disease outbreaks, natural disasters, limited water availability, disruption to hydropower energy generation, and animal migration. It should be noted that the ENSO impacts during these years were not necessarily more disastrous than climate and weather events in years lacking an influence from ENSO. The difference is that the ENSO impacts can be related to a specific and predictable climate phenomenon, whereas for many climate and weather events, scientists cannot trace the cause of an event to such a phenomenon.

ENSO in Context: Climate Variability

El Niño and La Niño aren't the only influences of climate around the world. Visit our climate variability resource page to learn more.

Among the effects of past ENSO teleconnections is the brown locust outbreak in southern Africa, which is associated with early winter rainfall. Such early rainfall can also lead to drought, crop failure and famine. During El Niño years, western Florida is more likely to experience above-average precipitation, in turn leading to increased water runoff and groundwater discharge during heavy rainfall. On the other hand, El Niño also tends to reduce the number of Atlantic hurricanes, and winter in the northern U.S. is usually more mild than average. Finally, La Niña years can bring more frequent and more damaging hurricanes to the western Atlantic Ocean. For other areas that typically see ENSO impacts, visit our map room.

All of that is because of ENSO?

At any given time, many processes are ongoing in the atmosphere, on land and in oceans all over the world. It is difficult to determine exactly which climate and weather events are a result of El Niño or La Niña and which are a result of other natural climate variabilities. ENSO is a strong force, however, and in many areas it is the most dominant influence on seasonal climate. Because of the uncertainty that climate variability presents, scientists cannot guarantee particular outcomes, but climate prediction can still be accurate a few months ahead of time.

What can we do?

Climatologists and decision makers can anticipate future ENSO impacts by studying its past effects. Although prediction involves uncertainty, the seasonal climate effects in some regions tend to shift in a particular way and thus result in a more likely set of impacts. For example, tropical regions are affected more strongly by ENSO, and while they may be at a higher risk for certain hazards, that also means that we may better anticipate these hazards and prepare for them.

Additionally, when good weather is predicted for an upcoming season, decision makers can capitalize on the forecast. Farmers, for example, can plan for a good season by planting additional or different crops, or by buying fertilizer to further increase their yield. A farmer may be less likely to make these investment risks in a bad year, but if he or she knows that it is probably going to be a good year, these risks can pay off.

An area's vulnerability to climate risks is also informed by its unique sociopolitical and economic characteristics. For example, a country in peacetime with developed infrastructure, highly organized emergency management, irrigated agriculture, and a well-informed population will be well equipped to respond to fires, floods, droughts or crop failures, even if it is in a climate-vulnerable region. On the other hand, a country with fewer resources may be more vulnerable to climate risks, even if it is in an area that typically sees fewer climate hazards. Preparing for the effects of ENSO therefore requires understanding the geography, vulnerability and culture of a given area.

Responding and adapting to climate risks requires significant organization. While the best time to create plans for preparedness for ENSO is when no event is occurring, this may be challenging in many areas. IRI provides a number of prediction tools and forecasts, as well as on-site training events for users with different skills and capabilities. Leaders and decision makers of various sectors - disaster management, public health, agriculture, water resources, etc. - can cooperate and communicate to ensure that resources are shared, information is up to date and accurate and that response is equitable for all stakeholders. Finally, the media can play a strong role in communicating risks by providing accurate information to the public.

Delve into the science

What to know more? Here are some recent publications from IRI scientists studying the influence of ENSO on local and regional climates:

Qian, J.-H., A. W. Robertson, and V. Moron, 2013: Diurnal Cycle in Different Weather Regimes and Rainfall Variability over Borneo Associated with ENSO. J. Climate, 26, 1772-1790. DOI: 10.1175/JCLI-D-12-00178.1.

Koide, N., A. W. Robertson, A. V. M. Ines, J.-H. Qian, D. G. DeWitt, and A. Lucero, 2013: Prediction of Rice Production in the Philippines using Seasonal Climate Forecasts. J. Appl. Meteor. Climatol., 52, 552-569. DOI: 10.1175/JAMC-D-11-0254.1

Qian, J.-H., A. W. Robertson, and V. Moron, 2010: Interactions between ENSO, Monsoon and Diurnal Cycle in Rainfall Variability over Java, Indonesia. J. Atmos. Sci., 67, 3509-3523. DOI: 10.1175/2010JAS3348.1

Allen, J. and D. Karoly, 2014: A Climatology of Australian Severe Thunderstorm Environments 1979-2011: Inter-annual Variability and the ENSO Influence. International J. Climatol. 34, 81-97. DOI: 10.1002/joc.3667

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IRI - International Research Institute for Climate and Society | Why do we care about El Niño and La Niña?

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El Niño Southern Oscillation, or ENSO, involves large-scale patterns of pressure, temperature, precipitation and winds that affect weather and climate over both the tropics and, through teleconnections, regions outside of the tropics. For an introduction to the science of ENSO, see our ENSO Essentials page.

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24. How hass tree ring growth or lack of growth support or refute climate change in the last 100 years?

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24. How hass tree ring growth or lack of growth support or refute climate change in the last 100 years?

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Trees are sensitive to local climate conditions, such as rain and temperature, they give scientists some information about that area’s local climate in the past.

For example, tree rings usually grow wider in warm, wet years and they are thinner in years when it is cold and dry. If the tree has experienced stressful conditions, such as a drought, the tree might hardly grow at all in those years.

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Quite a lot, actually!

But to understand what the trees tell us, we first have to understand the difference between weather and climate.

is a specific event-like a rain storm or hot day-that happens over a short period of time. Weather can be tracked within hours or days. is the average weather conditions in a place over a long period of time (30 years or more).

Scientists at the National Weather Service have been keeping track of weather in the United States since 1891. But trees can keep a much longer record of Earth's climate. In fact, trees can live for hundreds-and sometimes even thousands-of years!

One way that scientists use trees to learn about past climate is by studying a tree's rings. If you've ever seen a tree stump, you probably noticed that the top of the stump had a series of rings. It looks a bit like a bullseye.

These rings can tell us how old the tree is, and what the weather was like during each year of the tree's life. The light-colored rings represent wood that grew in the spring and early summer, while the dark rings represent wood that grew in the late summer and fall. One light ring plus one dark ring equals one year of the tree's life.

Because trees are sensitive to local climate conditions, such as rain and temperature, they give scientists some information about that area's local climate in the past. For example, tree rings usually grow wider in warm, wet years and they are thinner in years when it is cold and dry. If the tree has experienced stressful conditions, such as a drought, the tree might hardly grow at all in those years.

Scientists can compare modern trees with local measurements of temperature and precipitation from the nearest weather station. However, very old trees can offer clues about what the climate was like long before measurements were recorded.

In most places, daily weather records have only been kept for the past 100 to 150 years. So, to learn about the climate hundreds to thousands of years ago, scientists need to use other sources, such as trees, corals, and ice cores (layers of ice drilled out of a glacier).

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What Can Trees Tell Us About Climate Change?

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Tree rings can provide information about past climate!