http://www.physorg.com/news159025292.htmlCatastrophic sea levels 'distinct possibility' this century: study
April 15th, 2009 by Marlowe Hood
A breakthrough study of fluctuations in sea levels the last time Earth was between ice ages, as it is now, shows that oceans rose some three meters in only decades due to collapsing ice sheets.
The findings suggest that such an scenario -- which would redraw coastlines worldwide and unleash colossal human misery -- is "now a distinct possibility within the next 100 years," said lead researcher Paul Blanchon, a geoscientist at Mexico's National University.
The study, published by the science journal Nature, will appear in print Thursday.
Rising ocean water marks are seen by many scientists as the most serious likely consequence of global warming.
The UN Intergovernmental Panel on Climate Change (IPCC) predicted in 2007 that sea levels will rise by up to 59 centimeters (23 inches) before 2100 due simply to the expansion of warmer ocean waters.
This relatively modest increase is already enough to render several small island nations uninhabitable, and to disrupt the lives of tens of millions of people living in low-lying deltas, especially in Asia and Africa.
But more recent studies have sounded alarms about the potential impact of crumbling ice sheets in western Antarctica and Greenland, which together contain enough frozen water to boost average global sea levels by at least 13 metres (42 feet).
A rapid three-meter rise would devastate dozens of major cities around the globe, including Shanghai, Calcutta, New Orleans, Miami and Dhaka.
"Scientists have tended to assume that sea level reached a maximum during the last interglacial" -- some 120,000 years ago -- "very slowly, over several millennia," Blanchon told AFP by phone.
"What we are saying is 'no, they didn't'."
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