Ice-Core Record Details Earths Atmospheric History |
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Written by spacetravel.org
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Sunday, 27 November 2005 15:47 |
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A frozen record of the Earths atmosphere, 3,270 metres long and covering the last 650,000 years, has been obtained from the tiny air bubbles trapped in a deep Antarctic ice core. It is the longest ice-core record ever obtained, and reveals that changes in levels of greenhouse gases match changes in temperature.
The research was performed by the European Project for Ice Coring in Antarctica, led by Thomas Stocker of the University of Bern in Switzerland. The team has spent years drilling the ice core in Antarctica's Ice Dome Concordia.
The bubbles record how the planets atmosphere changed over six ice ages and the warmer periods in between. During all that time, the atmosphere has never had anywhere near the levels of greenhouse gases seen today. Today's level of 380 parts per million of carbon dioxide is 27% above its previous peaks of about 300 parts per million.
The match between temperatures and greenhouse gas levels help confirm predictions from climate models used to forecast future global warming
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