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900,000-year-old ice may destroy US case on Kyoto

Barbara McMahon in Rome and Paul Brown
Saturday April 23, 2005
The Guardian

An Italian expedition to the Antarctic has taken a sample of ice which is more than 900,000 years old and could give scientists evidence of past climate changes which would discredit global warming doubters.

The ice core, which is double the age of previous samples, will show how much carbon dioxide there was in the atmosphere during previous warm and cold phases in the climate and whether the current concentrations caused by burning fossil fuels are likely the lead to catastrophic global warming later this century.

The new core could be enough to discredit the fast diminishing band of climate sceptics, who have the ear of the Bush administration and who say that the climate has always fluctuated and man's destruction of forests and use of oil has nothing to do with the current rising temperatures and increased storminess across the world.

Ice cores contain layer after layer of snow which has fallen over millennia, and provide evidence of past climate in the same way as the growth rings of a tree. Once the tiny air samples trapped in the ice are analysed they will give scientists clear evidence of the volumes of gases and the temperature at the time.

Current scientific belief is that in all that time concentrations of greenhouse gases have not been as high as they are now, but the proof should be in these new ice cores.

President Bush used "uncertainties" in climate science, particularly the volume of carbon dioxide in the atmosphere during warm periods, to justify repudiating the Kyoto protocol when he was elected to office for the first time.

He said that cutting fossil fuel use would damage the US economy and that more scientific research was needed. Since then the science has become more certain, but this latest ice core could provide evidence that even hardliners would find hard to ignore.

World temperatures have risen in the past in direct relationship to the amount of greenhouse gases, mostly carbon dioxide and methane, in the air, but the new samples will enable scientists to analyse 10 to 12 glacial and interglacial cycles, compared with the four attained with the previous record holder, a 420,000-year-old ice core drilled by Russia's Ice Station Vostok five years ago.

Two chunks of ice were extracted, near the Italian-French ice station at Concordia on Antarctica's Dome C, the thickest ice sheet in the world, and in the Ross Sea. The first is some 900,000 years old.

Scientists now hope to reach the maximum attainable limit, taking samples that have been in existence for 1.5m years. These results of the European Project for Ice Coring in Antarctica (Epica) were made possible by drills able to penetrate some 3,000 metres below the surface of the polar ice cap.

Drilling started in 1996, and operations came to a close in 2004, with a final drill depth of 3,270.2 metres (10,730ft). The last stretch of coring was the hardest, with ice close to melting point.

Ten European nations took part: Belgium, Denmark, France, Germany, Italy, Norway, Holland, UK, Sweden and Switzerland with national and European financing.

The nine specialists from France and Italy will end their mission next November. To minimise the impact of human presence in the Antarctic a new burning facility has been created. Dioxin and other toxic emissions were eliminated and solid waste can be burnt.

Guardian Unlimited © Guardian Newspapers Limited 2005

http://www.guardian.co.uk/usa/story/0,12271,1468500,00.html