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Average Temperature of Ice Cores from 400,00 years ago in Celsius. - Justice K.

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this graph shows us how the average temperature in Antarctica changes yearly

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They could of got this information from past graphs and since they can't actually measure the temperature of the ice cores they have to measure the oxygen of isotope. - Justice
https://www.carbonbrief.org/factcheck-what-greenland-ice-cores-say-about-past-and-present-climate-change#:~:text=Ice%20cores%20are%20one%20of,with%20temperature%2C%20but%20imperfectly%20so.

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A misleading graph purporting to show that past changes in Greenland's temperatures dwarf modern climate change has been circling the internet since at least 2010.

Based on an early Greenland ice core record produced back in 1997, versions of the graph have, variously, mislabeled the x-axis, excluded the modern observational temperature record and conflated a single location in Greenland with the whole world.

More recently, researchers have drilled numerous additional ice cores throughout Greenland and produced an updated estimate past Greenland temperatures.

This modern temperature reconstruction, combined with observational records over the past century, shows that current temperatures in Greenland are warmer than any period in the past 2,000 years. That said, they are likely still cooler than during the early part of the current geological epoch - the Holocene - which started around 11,000 years ago.

However, warming is expected to continue in the future as human actions continue to emit greenhouse gases, primarily from the combustion of fossil fuels.

Climate models project that if emissions continue, by 2050, Greenland temperatures will exceed anything seen since the last interglacial period, around 125,000 years ago.

Ice cores as climate 'proxies'

Widespread thermometer measurements of temperatures only extend back to the mid-1700s. Scientists investigating how temperatures have changed prior to the invention of thermometers need to rely on a variety of climate " proxies ", which are correlated with temperature and can be used to infer, with some uncertainties, how it has changed in the past.

Climate proxies can be obtained from sources, such as tree rings, ice cores, fossil pollen, ocean sediments and corals. Ice cores are one of the best available climate proxies, providing a fairly high-resolution estimate of climate changes into the past.

Since scientists cannot directly measure temperatures from ice cores, they have to rely on measuring the oxygen isotope - 18O - which is correlated with temperature, but imperfectly so.

Odyssey of errors

A temperature reconstruction using the Greenland Ice Sheet Project 2 (" GISP2") ice core was first published by Prof Kurt Cuffey and Dr Gary Clow in a 1997 paper published in the Journal of Geophysical Research: Oceans. Prof Richard Alley of Penn State University also used the record in a 2000 paper. Neither of these papers provided a comparison of GISP2 record with current conditions, as the uncertainties in the ice core proxy reconstruction were too large and the proxy record only extended back to 1855.

The GISP2 ice core record was used in a number of papers in the late 1990s and 2000s that examined changes over the last ice age and the start of the current warm era - the Holocene - around 11,000 years ago. Around 2009, it caught the attention of Dr J Storrs Hall of the Foresight Institute, a technology-focused nonprofit group, who wrote a blog post suggesting that it disproved the idea that "human-emitted CO2 is the only thing that could account for the recent warming trend".

That post was republished on a climate sceptic blog called Watts Up With That, which followed up with its own version of a GISP2 graph in late 2010 by Dr Don Easterbrook, an emeritus professor of geology at the Western Washington University. Easterbrook's graph, shown below, was shared widely across the internet by climate sceptics and is still frequently seen - with many small variations - to this day in discussions on Twitter, blogs and news article comment threads.

This graph is misleading for a number of reasons.

First, the x-axis is mislabelled. In fact, it should say "Years before 1950", rather than "Years before present (2000 AD)". The GISP2 ice core only extends up to 1855 - 95 years before 1950. This means that none of the modern observational temperature period overlaps with the proxy reconstruction. (Easterbrook's graph shows the uptick in the final 100 years or so of the record - shown in red - incorrectly indicating that it is the observational temperature period.)

The figure was also featured in another post on the same blog, which conflated Greenland with global temperatures. Any individual location will have significantly more variability than the globe as a whole. A single ice core is also subject to uncertainties around elevation changes and other perturbations to the ice core over time.

As Prof Alley told then-New York Times journalist Andrew Revkin back in 2010:

"The data still contain a lot of noise over short times (snowdrifts are real, among other things). An isotopic record from one site is not purely a temperature record at that site, so care is required to interpret the signal and not the noise."

The GISP2 reconstruction is fairly old and more recent research has questioned the assumptions made in changing the relationship between temperature and 18O during the Holocene and how to best account for elevation change of the ice sheet at the GISP2 site. The GISP2 reconstruction changes the relationship between 18O and temperatures by a factor of two during the Holocene, while more recent reconstructions keep it constant. Similarly, elevation change influences 18O records. The old GISP2 reconstruction did not take elevation changes into account.

Scientists reconstructing past Greenland temperatures now use estimates from many different ice cores, which reduces the uncertainties associated with any single one and gives a more accurate picture of changes over Greenland as a whole.

Alley made this point explicitly, telling Revkin:

"So, what do we get from GISP2? Alone, not an immense amount. With the other Greenland ice cores... and compared to additional records from elsewhere, an immense amount... Using GISP2 data to argue against global warming is, well, stupid, or misguided, or misled, or something, but surely not scientifically sensible."

Multi-core reconstructions

A more modern Greenland temperature reconstruction, based on six different ice cores, was published by Prof Bo Vinther of the Niels Bohr Institute at the University of Copenhagen and colleagues in Nature in 2009.

Speaking to Carbon Brief, Vinther suggests that this multi-core Holocene reconstruction provides a number of advantages over the old GISP2 series, using ice core 18O data corrected for past elevation change and " tuned" to fit ice core borehole temperatures at four locations.

The six ice core sites used by the reconstruction are shown in the figure below.

The temperature reconstruction produced using data from all six ice cores is shown by the blue line in the figure below, and spans the period from 9690BC to AD1970. It has a resolution of around 20 years, meaning that each data point represents the average temperature of the surrounding 20 years. So, the end of the record - 1970 - shows the average temperature between 1960 and 1980.

The ice core data cannot be extended all the way through to present because, as Alley tells Carbon Brief, the snow that falls on the ice sheet needs time to form into solid ice. He explains that "it isn't quite enough to measure the snow as it falls...because there is a bit of post-depositional isotopic exchange and smoothing, so you'd want cores".

To extend this dataset up to the present day, Carbon Brief has taken observational temperature data from Berkeley Earth at the location of each of the ice cores and used a 20-year locally weighted smoothed (" LOWESS ") average of all the sites. This is a statistical approach that provides an estimate of long-term changes in the timeseries.

The black line in the figure below shows the observational record between 1880 and 2018. It is fitted to the ice core reconstruction during the period of overlap from 1880 through to 1970.

Greenland temperature reconstruction from Vinther et al. (2009) using proxy data from six ice cores. Data spans the past 12,000 years with a resolution of 20 years. Observational temperature data from Berkeley Earth is shown at the end in black, with a 20-year smooth applied to match the proxy resolution. Proxy records and observations are aligned over the 1880-1960 period.

Showing instrumental temperature observations alongside climate proxy records is often challenging in practice. As Alley tells Carbon Brief: "The question of how to join palaeoclimatic data to instrumental data is one of the oldest in this field and remains challenging."

Prof Vinther explains that showing proxy data and observations side-by-side is appropriate as long as the data both have the same "temporal resolution". In other words, because each point in both datasets represents an average of the 20 years of surrounding data, they can be more accurately compared. Because ice cores provide relatively high resolution temperature estimates, it is easier to compare them to observed temperatures than other proxy reconstructions that may only have one value in a century or more.

Recent temperatures in Greenland are still likely below those experienced in the early Holocene. This is similar to what is found in global Holocene temperature reconstructions, such as the one published by Prof Shaun Marcott and colleagues in Science in 2013, which suggested that "current global temperatures of the past decade have not yet exceeded peak interglacial values, but are warmer than during ~75% of the Holocene temperature history".

Recent temperatures are clearly higher than any seen in Greenland over the past two millennia. The figure below shows the ice core and observational temperature data zoomed in on the period from AD1 through to the present day.

Greenland temperature reconstruction over the past 2,000 years from Vinther et al 2009 and observational temperature data from Berkeley Earth with a 20-year smooth applied.

Looking into the future

While periods during the early Holocene - 7,000-11,000 years ago - may have been warmer in Greenland than the present day, if the present rate of warming continues, the Earth should pass well beyond any temperatures experienced in Greenland during the Holocene by 2050.

To examine how future Greenland warming might compare to what has happened in the past, Carbon Brief has looked at the average of the CMIP5 climate models used in the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report. Future projections from these models are taken from the locations of the six ice cores used by Vinther and colleagues.

Two future scenarios, known as " Representative Concentration Pathways", are used: representative concentration pathway RCP4.5, a modest mitigation scenario where global temperatures warm to nearly 3C above pre-industrial levels by 2100, and RCP8.5, a very high emissions scenario where global temperatures warm nearly 5C by 2100.

Climate models show faster warming in the Arctic than the rest of the world - a phenomenon known as arctic amplification - and similar to what has been observed over the past few decades. By 2100, these models have the area above the Greenland ice core locations warming by nearly 4C in RCP4.5 and more than 7C in RCP8.5.

The figure below shows a 20-year LOWESS smoothed average of the models from 2000 through to 2100 added on to the end of the observational temperature data. Temperatures clearly exceed any experienced in Greenland during the Holocene by 2050 and are much warmer by 2100.

Greenland temperature reconstruction over the past 12,000 years from Vinther et al 2009 combined with both observational temperature data from Berkeley Earth from 1880-2018 and CMIP5 multimodel mean projections from 1999-2100. A 20-year smooth is applied to annual Berkeley Earth and CMIP5 data. Proxy records and observations are aligned over the 1880-1960 period, while climate models and observations are aligned over the 1999-2018 period.

Just looking at the past 2000 years - and next 100 - shows a similar rapid rise at the end of the record. The rate of warming over the next century is projected to be far faster than anything seen since the end of the last ice age.

Greenland temperature reconstruction over the past 2,000 years from Vinther et al 2009, observational temperature data from Berkeley Earth and CMIP5 models data with a 20-year smooth applied.

Conclusion

Greenland ice cores provide a high-quality high-resolution estimate of past changes in temperatures, allowing more precise comparisons with observed temperature records than most other climate proxies. While current temperatures are likely still below the highs in the early Holocene around 7,000 years ago, they are clearly higher than any temperatures experienced in Greenland over the past 2,000 years.

Greenland is just one location and temperature variations seen in ice core records may not be characteristic of global temperatures. However, global proxy reconstructions have tended to show similar patterns, with current temperatures lower than the early Holocene maximum.

Unless greenhouse gas emissions cease in the near future, warming will continue and, by the middle of the 21st century, Greenland - and the world as a whole - will likely experience temperatures that are unprecedented at least since the last interglacial period 125,000 years ago.

References

Cuffey, K. M., & Clow, G. D. (1997). Temperature, accumulation, and ice sheet elevation in central Greenland through the last deglacial transition. Journal of Geophysical Research: Oceans, 102(C12), 26383-26396. http://doi.org/doi:10.1029/96JC03981

Alley, R. B. (2000). Ice-core evidence of abrupt climate changes. Proceedings of the National Academy of Sciences, 97(4), 1331 LP-1334. http://doi.org/10.1073/pnas.97.4.1331

Vinther, B. M., et al. (2009). Holocene thinning of the Greenland ice sheet. Nature, 461, 385. https://doi.org/10.1038/nature08355

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Factcheck: What Greenland ice cores say about past and present climate change

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A misleading graph purporting to show that past changes in Greenland's temperatures dwarf modern climate change has been circling the internet since at least 2010. Based on an early Greenland ice core record produced back in 1997, versions of the graph have, variously, mislabeled the x-axis, excluded the modern observational temperature record and conflated a single location in Greenland with the whole world.

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They asked Dr. Shenk really nicely and he told them

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The temperature in Antarctica. it is also showing the global temperature for the last 300,000

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This information was estimated from them measuring the oxygen of isotope. Looking at the article Justice provided, I also agree with her answer. The evidence that she provided made it easier for me not to confuse it with something else.

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how the degrees incresses

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More and less sunlight through the course of 400000 years

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More and less sunlight through the course of 400000 years

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Sean m

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by keeping track , drilling into the ice

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this graph shows how the temperature of the ice cores in antarctica  increases and decreases 

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this graph shows how the temperature of the ice cores in antarctica  increases and decreases 

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-naz

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This is showing us the average yearly temperature globally of ice cores for the last 400,00 years.

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The graph shows the temperature on how it evolved an show how the temperature and how it increase and decrease

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To analyze the age of the deepest layers, scientists use a variety of methods, including measurements of the chemical composition and electrical conductivity of the ice.

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they obtained this data by studying  the ice core and seeing how its changes over time - naz

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they obtained this data by studying  the ice core and seeing how its changes over time - naz

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Scientists gained most of this information by traveling ice sheets. They use a drill that drills down into the ice to recover and record the atmospheric carbon dioxide.

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What's the first thing that comes to mind when you hear Antarctica or Greenland? If you're like most people, the answer is probably ice and lots of it. And it is ice that draws paleoclimatologists literally to the ends of the Earth in the quest for knowledge about where our planet has been, where it is, and where it might be going.

Ice cores provide a unique contribution to our view of past climate because the bubbles within the ice capture the gas concentration of our well-mixed atmosphere while the ice itself records other properties. At the Earth's highest latitudes and altitudes, ice is typically the only environmental data available for scientists to reconstruct the climate hundreds to thousands of years ago.

Scientists obtain this information by traveling to ice sheets, like Antarctica or Greenland, and using a special drill that bores down into the ice and removes a cylindrical tube called an ice core. Drilling thousands of meters into ice is a feat of technology, endurance, and persistence in extreme environments, exemplified by the joint Russian, U.S., and French team that worked together to recover the iconic record of atmospheric carbon dioxide from the ice at the Russian Vostok Station in Antarctica in 1987. In 2012, Russian scientists extended the ice core to an incredible 3,768 meters, reaching Lake Vostok underneath the East Antarctic Ice Sheet.

After scientists procure the cores, they slice them up into various portions each allotted to a specific analytical or archival purpose. As the scientists are dividing the cores for analysis, they don special clean suits to prevent the core samples from becoming contaminated. Once the samples have been prepared, the scientists run a variety of physical and chemical analyses on the cores. Some of these ice procedures are consumptive, meaning their analysis requires destruction of the ice, while others have no effect on the ice. Scientists study the gas composition of the bubbles in the ice by crushing a sample of the core in a vacuum. Overall, most of the core is reserved for archival purposes, preserving a long record of Earth history for future research.

These cores have distinct layers in them that form throughout the years. With each passing year, snow falls over the ice sheets and each layer of snow has a different texture and a different chemistry, with winter snow differing from summer snow as well. During the summer, when the sun is up for 24 hours many days, the top layer of the snow changes in texture. As winter arrives and it turns cold and dark again, new snow falls on top of the summer snow forming distinct layers. Each of these layers provides scientists with a vast amount of information about the climate each year.

Ice cores can tell scientists about temperature, precipitation, atmospheric composition, volcanic activity, and even wind patterns. The thickness of each layer allows scientists to determine how much snow fell in the area during a particular year. When several cores are taken from nearby locations, scientists can also determine wind patterns based on where the snow drifted, which can be interpolated from the thickness of the layers in the cores. And, the chemical composition of the snow itself can tell scientists about the temperatures in the area as colder temperatures lead to a higher concentration of a particular oxygen isotope in the snow.

Depending on atmospheric conditions, dust from nearby locations can also accumulate in the layers of the ice cores. In addition to seasonal dust, gigantic volcanic eruptions anywhere on the globe can spew enormous quantities of dust into the atmosphere that can accumulate in the ice. All of the dust layers, combined with the chemical composition of the ice and a flow model that assesses how the ice accumulates over time allow scientists to date the age of the ice cores.

Scientists tie all of these different threads of information provided by the ice cores together and weave them into a single continuous picture of the Earth's past climate. Visit the Ice Core page to access these data from NCDC's Paleoclimatology Program.

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Picture Climate: What Can We Learn from Ice?

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What's the first thing that comes to mind when you hear Antarctica or Greenland? If you're like most people, the answer is probably ice and lots of it. And it is ice that draws paleoclimatologists literally to the ends of the Earth in the quest for knowledge about where our planet has been, where it is, and where it might be going.

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Well to analyze the (cyclical change) or in other terms how to analyze the predicted weather change you would have to spend months maybe even years of studying these changes to predict how the cycle is going to change next

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this could cause that it might start melting

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yes and i think its because of the climate change

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This graph shows the (change in) estimated average annual temperature in C in Antarctica over the past ~500,000 years

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Yes I do think that we are experiencing temperature changes in Connecticut because the earth is warming. Overall, Connecticut has mild winters and warm summers.

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its caused cause of the earths axis

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It is because the earth's axis is tilted that it warms up in the summer and cools down in the winter. A lot of people believe the temperature changes because the earth is closer to the sun in summer and farther from the sun in winter. It actually is farthest from the sun in July and is the closest to the sun in January. The difference between seasons and climate is that season "is a weather-based subdivision of the year." and climate is just weather in an area or over a long period of time.

https://www.askdifference.com/season-vs-climate/

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My birthday is in the summer and I like when it's warm out so the Earth warms up for my birthday and then gets cooler afterwards to balance it out 😎😎😎

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the earth rotates around the sun at an angle, when one part of the earth gets more sun light than the other that what we call summer, and the other part gets no sunlight so then its colder and that's what we call winter - naz 

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the earth rotates around the sun at an angle, when one part of the earth gets more sun light than the other that what we call summer, and the other part gets no sunlight so then its colder and that's what we call winter - naz 

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A few things that could cause this is the change of the weather over the course of 400,00 years. The weather could get warmer which could melt the ice  Also many things have evaluated since then too.

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the data from the graph was gained by them study the ice cores climate changes

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MANNY                                 yeah i do, i think its getting colder because its keeps getting cold as flip outside    

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MANNY                                 yeah i do, i think its getting colder because its keeps getting cold as flip outside    

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Yes, we experience big temperature changes here in Connecticut. This is because we live at a relatively high latitude where the amount of sunlight varies significantly over the course of the year

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yes, there would be a nice hot sunny day and then there will be a freezing cold breeze

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Yes we do experience changes in temperature. You would think that in the winter the weather gets colder due to snow, but over the years weather in the winter is actually getting warmer. This is because the earth is increasing by heat over the years. This is the reason why we have hot dry summers too and cool winters.

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ice drilling may cause it over the course of 400,000 years

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The antarctic temperature changing over the years

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To unlock the information inside an ice core, researchers in the lab may melt or crush the sample bit by bit; each deeper layer represents a slightly earlier time in the Earth's climate history. The ice arrives in small strips, about 1-by-1 inch apiece, which are smaller slices of the roughly three-foot-long, coffee-can-wide pieces a drill pulls out of a glacier.

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Like a prehistoric fly trapped in amber during dinosaurs' days, airborne relics of Earth's earlier climate-including dust, air bubbles, sea salts, volcanic ash, and soot from forest fires-can end up trapped in glacial ice for eons. To climate scientists, those relics tell a story about how our planet's climate and atmosphere have changed over thousands of years.

What they find out could have an impact on worldwide civilization within a few generations-especially in coastal regions. Ice cores may reveal whether Antarctica's western ice sheet melted fully the last time Earth's climate warmed to the temperatures the planet is predicted to reach in the next two centuries. If it did, it's likely to again, which would raise sea levels significantly enough to threaten many seaside cities.

"We have some evidence that may have happened, but we aren't sure," says Erich Osterberg, who studies ice cores as an assistant professor in the Department of Earth Science at Dartmouth College.

Unlocking ice cores' secrets

To unlock the information inside an ice core, researchers in the lab may melt or crush the sample bit by bit; each deeper layer represents a slightly earlier time in the Earth's climate history. The ice arrives in small strips, about 1-by-1 inch apiece, which are smaller slices of the roughly three-foot-long, coffee-can-wide pieces a drill pulls out of a glacier.

Sometimes researchers are studying actual bubbles of the early atmosphere, trapped in the ice as it formed. To collect them, they crush the sample under a vacuum hood, which keeps other air out while they pull the newly released air into vials.

Scientists run melted samples through various instruments-mass spectrometers, scanning electron microscopes, gas chromatographs-to find tiny pieces of pollution, like sulfates, traces of metals, or radioactive fallout, or natural aerosols like dust or volcanic ash.

Because every clue in the ice, whether a grain of sea salt or an air bubble, is so miniscule and the measurements must be incredibly precise, any analysis must be done in a "clean room" setting. The researchers wear body suits and multiple layers of gloves; the room must have ultraclean filters and vents to keep the air pristine.

"Even just a fingerprint from a scientist holding the core can ruin the sample," Osterberg says.

Mystery in the melt

After analyzing enough ice core slices, which may each represent anywhere from a week to a year of time, a researcher can look for patterns to track changes in the atmosphere's composition and temperature, and what activity on Earth shaped it.

The ratio of "light" oxygen-16 to "heavy" oxygen-18 in a sample, for instance, reveals the global temperature when the ice formed; it takes colder temperatures for water vapor containing the lighter oxygen isotope to turn into precipitation. Examining the gasses trapped in ice cores is how scientists first learned that the amount of carbon dioxide and the global temperature have been linked at least the last million years of Earth's history.

Osterberg even thinks ice cores will help figure out whether Antarctica's western ice sheet melted 125,000 years ago, the last time Earth's climate warmed to the temperatures the planet is predicted to reach in the next two centuries.

Scientists hope to collect a new ice core from the eastern side of the Trans-Antarctic Mountains, which today separate the East and West Antarctic Ice Sheets. Much of the land under the West Antarctic Ice Sheet is below sea level. If the ice sheet did disintegrate, then the proposed ice core drilling location-presently in the middle of the frozen continent-would have been coastal real estate 125,000 years ago.

"We would see much warmer temperatures and higher levels of sea salt reflected in the ice core chemistry if this location was hundreds of miles closer to the ocean in the past," Osterberg said.

Ice core trekkers

Before the climate fossils can tell their stories, however, they must be retrieved. Rugged researchers like Osterberg and his colleagues may spend multiple summers scoping never-before-explored areas on glaciers before trekking out to collect a core. To pick the spot, they check the ice's thickness and layers (the flatter the better) and put out GPS markers to track how quickly the ice is flowing and deforming (the slower the better).

Setting up base camp and drilling into the ice may take six to eight weeks for two cores that are each 700 feet long, Osterberg says. Some researchers, particularly in Antarctica, may drill two miles and take much longer.

"Something always goes awry," Osterberg says. "You're doing this in one of the most extreme environments you can imagine-far from help, remote, with not a lot of spare parts."

And that's before dealing with weather and wildlife.

When drilling an ice core at a remote site in Greenland in 2012, his team found out that a hurricane-strength storm was headed their way. Because their tents and equipment were high up on an unprotected, rocky ridge, the best defense would have been to move down into the valley. But they'd camped up high for a reason-warming temperatures in the region had been melting sea ice, which was driving many polar bears onto the land. The ridge was the best place to avoid them.

"We had to chose between storm and polar bear," Osterberg says. They chose storm-and lost most of their tents as a result, though help reached them in a few days.

The difficulties don't end when the core is drilled. Moving ice cores from a drilling site to the various laboratories worldwide that want a piece is a whole other challenge. The cores are usually airlifted off the top of the mountain, then shipped by air or truck in refrigerated crates, racing against the clock before they start to degrade. Precautions include paying customs officials to babysit crates on airport tarmacs and hiring a second truck to follow the first in case it breaks down.

"There's no insurance dollar you can put on it: they're priceless," Osterberg says.

****
The Paleoclimatology Branch at NOAA's National Climatic Data Center doesn't warehouse actual ice cores, but it is the world's largest archive of climate and paleoclimatology data. By providing a long-term, permanent home for data collected by researchers across the world, the group ensures that ice core and other ancient climate data is available to all scientists who are trying to understand and model climate and environmental changes that occur over hundreds or thousands of years.

Links

NOAA Paleoclimate Data
The Oxygen Balance from NASA Earth Observatory
Ice Core Proxy Methods for Tracking Climate Change (ProQuest)
Greenland Ice Sheet Project 2 (University of NH Climate Change Research Center)

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Climate at the core: how scientists study ice cores to reveal Earth's climate history | NOAA Climate.gov

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Like a prehistoric fly trapped in amber during dinosaurs' days, airborne relics of Earth's earlier climate can end up trapped in glacial ice for eons. How do climate scientists turn those tiny relics into a story about Earth's ancient climate?

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After analyzing enough ice core slices, which may each represent anywhere from a week to a year of time, a researcher can look for patterns to track changes in the atmosphere's composition and temperature, and what activity on Earth shaped it.

The ratio of "light" oxygen-16 to "heavy" oxygen-18 in a sample, for instance, reveals the global temperature when the ice formed; it takes colder temperatures for water vapor containing the lighter oxygen isotope to turn into precipitation. Examining the gasses trapped in ice cores is how scientists first learned that the amount of carbon dioxide and the global temperature have been linked at least the last million years of Earth's history.

Osterberg even thinks ice cores will help figure out whether Antarctica's western ice sheet melted 125,000 years ago, the last time Earth's climate warmed to the temperatures the planet is predicted to reach in the next two centuries.

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It changes when the e

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The scientist drilled into ice core samples from very deep underneath the ice and study the ice core temperatures of time to see if the levels change

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This video describes the facts surrounding the Vostok Ice Core. He also explains why global atmospheric temperatures increase.

https://www.youtube.com/watch?v=8BgD9xul16g&feature=emb_logo

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In Hartford, the summers are warm, the winters are very cold, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 21°F to 84°F and is rarely below 6°F or above 92°F.

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Yes , I feel like in Connecticut we do experience a lot big changes in the weather throughout the year. I think we experience these kind of changes because the Earth is warming, the cause of that is since the 1700s the carbon dioxide in the air has increased 40 percent therefore the Earth might become warmer. Also, the green - house gases are also causing the surface of our lower atmosphere to become 1 degree warmer in the last 50 years.

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It is all about the tilt of the Earth’s axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!

During the summer, the sun’s rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.

During the winter, the sun’s rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot. Also, the long nights and short days prevent the Earth from warming up. Thus, we have winter!

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Answer

Because the earth's axis is tilted.

Earth at the beginning of each season. From National Weather Service, National Oceanic and Atmospheric Administration Web site.

It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!

During the summer, the sun's rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.

During the winter, the sun's rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot. Also, the long nights and short days prevent the Earth from warming up. Thus, we have winter!

Clockwise from top left:
Winter in Yellowstone National Park. National Park Service Web site.
Rural Alabama in the spring. Carol M. Highsmith Collection, Library of Congress.
Soybean and corn fields ready for harvesting in late summer in Carroll County, Indiana. Carol M. Highsmith Collection, Library of Congress.
Colorado's Delores River Valley in autumn. Carol M. Highsmith Collection, Library of Congress.

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Why is it hot in summer and cold in winter?

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Because the earth's axis is tilted. Earth at the beginning of each season. From National Weather Service, National Oceanic and Atmospheric Administration Web site. It is all about the tilt of the Earth's axis.

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manny                                          it shows how around every 30 years there are mayor temperature changes      

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manny                                          it shows how around every 30 years there are mayor temperature changes      

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By drilling and using ice cores to measure it over the years

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This is due to the earth axis changing. So when its summer the earth tilts to where the sun rays hit our side of the earth more than usual. Also the days in the summer are much longer than in any other season because summer odes not have day light savings. This causes the days to warm up fast also.

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The Graph Shows us how the weather every 30 years.