Blog Archive

Monday, December 14, 2009

Robert Corell, Dahl-Jensen express great concern over the increasing velocity of glacier outflow on Greenland; Gore focuses on water scarcity looming for a billion people

Robert Corell, Dahl-Jensen express great concern over the increasing velocity of glacier outflow on Greenland; Gore focuses on water scarcity looming for a billion people

COPENHAGEN (AFP) – Climate guru Al Gore warned UN climate talks Monday that the record melting of glaciers worldwide could deprive more than a billion people of access to fresh water.

"There are more than a billion people on the planet who get more than half of their drinking water -- many of them all of their drinking water -- from the seasonal melting of snow melt and glacier ice," Gore said at the release of a report he co-sponsored.

A triple threat from crumbling ice sheets, disappearing glaciers and the shrinking Arctic ice cap are feeding global warming and will fuel rising sea levels, the report found.

Adding to an avalanche of bad scientific news over the last two years, the former US vice president also cited new research showing that the Arctic ice cap may have shrunk to record-low levels last year.

"2008 had a smaller minimum, probably, than 2007," Gore said, alluding to work led by California-based researcher Wieslaw Maslowski.

"Some of the models suggest to Dr. Maslowski that there is a 75% chance that the entire polar ice cap during some summer months could be completely ice free within five to seven years," Gore said.

Scientists reported in September that the Arctic ice cover -- which helps beat back the Sun's heat-delivering rays back into space -- had reversed course compared to 2007, when it had shrunk to its smallest size since the start of accurate measurements some four decades ago.

But when measured by volume, it turns out that the 4.5 million km² (1.7 million sq miles) area in 2008 was actually smaller than the year before.

The Arctic ice cover does not affect sea levels, but is a critically important barrier to global warming.
Intact, its white surface acts as a mirror, but when the ice disappears it becomes a sponge.

"Instead of 85% of the solar energy being reflected, 85% is absorbed in the Arctic Ocean," said Gore who was awarded the Nobel Peace Prize in 2007 for his work on warning of the threat posed by climate change.

One of the report's authors, Robert Corell of the H. John Heinz III Center for Science, Economics and the Environment in Washington, pointed to another threat: the massive, accelerating loss of mass -- measured in hundreds of billions of tonnes per year -- from icesheets in Greenland and Antarctica.

Combined with the expansion of ocean water due to global warming, the continent-sized icesheets are now set to contribute to a global sea level rise of about a metre by the end of the century, double the mid-point prediction of the UN's benchmark science report in 2007.

"A one meter rise equals 100 million people who will have to move, one hundred million environmental refugees," said Corell.

"We have woken giants," said Arctic ice specialist Dorothe Dahl-Jensen at Copenhagen University of the ice sheets.

"This is really scary. This really shakes us scientists. These icesheets are enormous," she said in presenting a second report on Greenland from the Arctic Monitoring and Assessment Programme.

Greenland's ice block holds enough frozen water to lift seas seven metres, while West Antarctica could add another five metres to the global water mark.

Dahl-Jensen said the pace at which some glaciers on the west coast of Greenland were "calving," or falling into the sea, has sped up dramatically over the last decade.

"This is by far the fastest flowing ice we have ever dreamed of. This is a rate of loss that we have never seen before," she said.

Both scientists pointed out that all of these impacts had been unleashed by a less than 1.0 °C (1.8 °F) increase of global temperatures since pre-industrial times.

"Current proposals from individual countries for their own actions would lead to a temperature increase of approximately 3.8 °C (6.8 °F)", by the end of the century, Corell said.


No comments: