Sunday, March 08, 2009

SCIENTISTS: FIVE FOOT RISE IN SEA LEVELS BY 2100 POSSIBLE

Guardian, UK - Scientists will warn this week that rising sea levels, triggered by global warming, pose a far greater danger to the planet than previously estimated. There is now a major risk that many coastal areas around the world will be inundated by the end of the century because Antarctic and Greenland ice sheets are melting faster than previously estimated.

Low-lying areas including Bangladesh, Florida, the Maldives and the Netherlands face catastrophic flooding, while, in Britain, large areas of the Norfolk Broads and the Thames estuary are likely to disappear by 2100. In addition, cities including London, Hull and Portsmouth will need new flood defenses.

"It is now clear that there are going to be massive flooding disasters around the globe," said Dr David Vaughan, of the British Antarctic Survey. "Populations are shifting to the coast, which means that more and more people are going to be threatened by sea-level rises.". . .

The International Panel on Climate Change - when it presented its most up-to-date report on the likely impact of global warming in 2007 - concluded that sea-level rises of between 20 and 60 centimeters [8-23 inches] would occur by 2100. These figures were derived from estimates of how much the sea will increase in volume as it heats up, a process called thermal expansion, and from projected increases in run-off water from melting glaciers in the Himalayas and other mountain ranges.

But the report contained an important caveat: that its sea-level rise estimate contained very little input from melting ice sheets in Antarctica and Greenland. The IPCC forecast therefore tended to underestimate forthcoming changes. . .

These revisions suggest sea-level rises could easily top a meter by 2100 - a figure that is backed by the US Geological Survey, which this year warned that they could reach as much as 1.5 meters [five feet]