Tuesday, November 29, 2005

Air today has the highest fix of CO2 in over a half a million years

Carbon dioxide (CO2) that is known as the principal gas driving global warming is also well understood to have reached alarming levels. But a new 10-country European study into Antarctica's ice cores startlingly suggests that levels are nearly a third higher than any point in 650,000 years.

In the run up to a major UN summit on global warming in Canada, the study provides compelling evidence of man's role in changing the Earth's climate system.

The new revelation owes its origins to the deepest ice core in the world located at a site dubbed Dome Concordia in the Eastern Antarctica. European scientists have drilled into the core using a 10 cm wide drill bit to extract ice deposited over 650,000 years ago as identified from the layers of annual snowfall.

The analysis of the ice for trapped bubbles of carbon dioxide shows that at no point in the intervening years were the levels close to current day concentrations of 380 part per million. This leads scientists to believe that the rising CO2 concentrations today are at least 27 percent more than the highest levels ever seen in 650,000 years.

The study appearing in the journal Science also suggests that in the world's pre-industrial times up until the mid 19th century, the CO2 concentrations had been at least a 100 parts per million lower than today. The study's lead author Thomas Stocker of the University of Bern in Switzerland said the results were “another piece” to show how man influenced atmospheric compositions in shorter time scales “compared to natural cycles of the climate system”. Events like volcanic eruptions are known to release into the atmosphere large volumes of methane, carbon dioxide and nitrous oxide that contribute to Earth's rising surface temperature. But the new evidence clearly links the rising carbon dioxide concentrations to man's industrial and economic activity in the last two centuries.

If in just five years, average global temperatures haves risen by 100 times and nearly 0.2 C over what is expected for such a period, one can imagine what the world can expect in years to come. 2005 is already on course to be dubbed the hottest year in Earth's known history. With this kind of temperature change comes a quicker meltdown of polar icecaps and a consequent twice as fast ocean-rise, which as per evidence from tidal gauges from 1850 and recent satellite imagery is currently 2 mm a year.

With this study the European Project for Ice Coring in Antarctica (EPICA) has set a record that previously stood at the depths of 210,000-year old ice in another part of Antarctica. However, it appears that as quickly as man discovers his past, he is even after destroying his future. Professor Kenneth Miller of Rutgers University said, “Now with solid historical data, we know it (climate change and ocean rise) is definitely a recent phenomenon”.

He alongside other researchers are hoping that the combined wealth of evidence provided by these studies help in sharpening the world's resolve to cut carbon pollution that the Kyoto Protocol sought to facilitate. Meanwhile, there is hope that this meeting at Montreal augurs a change in stance on the part of America that so far has steered clear of signing its pledge to reduce carbon dioxide pollution.



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