Next ice age is 15,000 years away By Deborah Smith June 10, 2004
There will not be a sudden ice age the day after tomorrow. In fact, one is not due for at least another 15,000 years, according to scientists who have drilled an ice core in Antarctica that contains snowfall from the past 750,000 years. The three-kilometre-long core is the oldest obtained so far, and spans eight ice ages and eight warmer interglacial periods. It took eight years for the European team - real-life equivalents of the character played by Dennis Quaid in the disaster movie The Day After Tomorrow - to obtain the cylinder of ice, which is 10 centimetres in diameter. They worked in temperatures of minus 40 degrees, at a site called DomeC, more than 1000 kilometres from the nearest Antarctic research base. Eric Wolff, of the British Antarctic Survey, said: "It's very exciting to see ice that fell as snow three quarters of a million years ago." Although there would not be an ice age soon, "we may have a heatwave if we are unable to control carbon dioxide emissions and other greenhouse gases entering the atmosphere", he said. The benefit of an ice core is that it contains ancient air that was trapped between snow crystals as they formed ice, allowing past levels of greenhouse gases to be determined. Preliminary results obtained by the researchers from the European Project for Ice Coring in Antarctica show present carbon dioxide levels are the highest in the past 440,000 years, they report in the scientific journal Nature today. Most warmer periods between ice ages have lasted about 10,000 years. An exception was 430,000 years ago, when the ensuing warmer interglacial interval lasted 28,000 years. The team used the new core to study levels of greenhouse gases and the size of the temperature change at that time. Dr Wolff said this transition resembled the shift 12,000 years ago, from an ice age to today's warm climate. "Given the similarities between this earlier warm period and today, our results may imply that without human intervention a climate similar to the present one would extend well into the future.".
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