European lead in reading past climates from ice coresOctober 12, 2007Climate change is a reality today, but how can we find out about the future dangers it poses" What we really need is a full record of the Earth's climate for several hundred thousand years, complete with samples of air from different epochs that can be taken to the lab for analysis. Incredibly, this record exists, in the icecaps of the Arctic and Antarctic regions, and a European Science Foundation programme has a key role in deciphering it. Professor Thomas Stocker of the University of Bern in Switzerland is one of the principal investigators of EPICA (European Programme for Ice Coring in Antarctica.) Stocker explains that EPICA, a joint ESF- European Commission (EC) effort funded by the Commission and 10 national agencies, has put Europe in a leading position in ice core research, in which specially designed drilling technology is used to obtain continuous ice sequences 3.8 thousands of metres in length. A series of EPICA papers in prestigious journals such as Nature and Science are evidence of its world importance. The principle behind ice coring is straightforward. Snow falls in Greenland and the Antarctic, but conditions there are too cold for it to melt. In most places it will eventually be carried away by glacial movement, but it is possible to find areas where the snow has piled up for hundreds of thousands of years, turning to ice as the weight of later snowfall builds up on top. Drilling out a core of such ice reveals the past in a neat sequence of millennia. Better still, the ice contains information about the past. It includes trapped air bubbles that can be analysed to reveal the composition of the ancient atmosphere. Layers of ash reveal ancient volcanic eruptions. And the ratio of different isotopes of oxygen in the ice is a virtual thermometer that tells us past temperatures. The more of the lighter isotope, oxygen 16, there is, the colder it was. Stocker says: "Ice-drilling is an area in which Europe has taken a decisive technological and scientific lead in the past decade. We now have a continuous record of 800,000 years of climate history, thanks to EPICA and other European initiatives." These ice cores directly illuminate current climate debates. As Stocker points out, air bubbles allow us to measure how much methane and carbon dioxide there was in the air when the snow fell. These - especially carbon dioxide - are the principal greenhouse gases in the Earth's atmosphere. It is clear that they are now at their most abundant for hundreds of thousands of years. By contrast, the most-used direct measurements of atmospheric carbon dioxide, made on Hawaii, only date back to 1958. So as Stocker says: "EPICA results form a cornerstone of the current climate debate." EPICA has been responsible for drilling and investigating two deep ice cores in Antarctica. One was at a site called Dome C, and the other at Kohnen research station in Queen Maud Land. At Dome C, ice was drilled out to a depth of 3270m, stopping in December 2004 just 5m above the rocky basement below. Because of the immense pressure at this depth, there is liquid water above the rock, so drilling was stopped to avoid polluting it. At Kohnen station, drilling was completed in January 2006 at a depth of 2774m, where the ice was estimated to be 150,000 years old. Stocker says that this research is being pushed forward under the umbrella of the current International Polar Year, in which ESF is a contributor. Recently a new project called NEEM (North Greenland Eemian Ice Drilling) has been launched to investigate the Eemian period in Earth history. This warm period from about 130,000 to 115,000 years ago shares similarities with an imminent future greenhouse Earth, and it had sea levels about 7m higher than those we observe today. The NEEM project forms part of IPICS, the International Partnership in Ice Core Sciences. Stocker explains that one of the aims of IPICS is to find the oldest ice in Greenland, probably in the north-west of the island, so that we can get a clear comparison between Arctic and Antarctic narratives of Earth history. While these cores still have plenty to tell us, Stocker and his colleagues are in little doubt about the overall message. They think that climate "forcing" by greenhouse gases is a very real phenomenon: in other words, that rising greenhouse gas concentrations drive the Earth's temperature upwards in a very direct way. So the ice cores now deposited in cold "stores" around the world have a clear message for us all. European Science Foundation |
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| Related Ice Core Current Events and Ice Core News Articles Queen's scientists on international team discover 'ecologically unique' changes in Arctic lake Queen's University biologists are part of an international research team whose discovery of a rare sediment core in a remote Arctic lake provides compelling evidence of unprecedented environmental changes occurring over the past few decades. As Greenland melts Not that long ago - the blink of a geologic eye - global temperatures were so warm that ice on Greenland could have been hard to come by. Today, the largest island in the world is covered with ice 1.6 miles thick. Even so, Greenland has become a hot spot for climate scientists. International Greenland ice coring effort sets new drilling record in 2009 A new international research effort on the Greenland ice sheet with the University of Colorado at Boulder as the lead U.S. institution set a record for single-season deep ice-core drilling this summer, recovering more than a mile of ice core that is expected to help scientists better assess the risks of abrupt climate change in the future. Ancient drought and rapid cooling drastically altered climate Two abrupt and drastic climate events, 700 years apart and more than 45 centuries ago, are teasing scientists who are now trying to use ancient records to predict future world climate. New cleaning protocol for future 'search for life' missions Scientists have developed a new cleaning protocol for space hardware, such as the scoops of Mars rovers, which could be used on future "Search for Life" missions on other planets. Sea level rise of 1 meter within 100 years New research indicates that the ocean could rise in the next 100 years to a meter higher than the current sea level - which is three times higher than predictions from the UN's Intergovernmental Panel on Climate Change, IPCC. Study: Did early climate impact divert a new glacial age? The common wisdom is that the invention of the steam engine and the advent of the coal-fueled industrial age marked the beginning of human influence on global climate. Scientists probe Antarctic glaciers for clues to past and future sea level Scientists from the U.S., U.K. and Australia have teamed up to explore two of the last uncharted regions of Earth, the Aurora and Wilkes Subglacial Basins, immense ice-buried lowlands in Antarctica with a combined area the size of Mexico. Gas from the past gives scientists new insights into climate and the oceans In recent years, public discussion of climate change has included concerns that increased levels of carbon dioxide will contribute to global warming, which in turn may change the circulation in the earth's oceans, with potentially disastrous consequences. Greenland Ice Core Reveals History of Pollution in the Arctic New research, reported this week in the online early edition of the Proceedings of the National Academy of Sciences, finds that coal burning, primarily in North America and Europe, contaminated the Arctic and potentially affected human health and ecosystems in and around Earth's polar regions. More Ice Core Current Events and Ice Core News Articles |
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