| One of the glaciers on Greenland’s east coast
St Louis (Kansas), Feb. 17 (Reuters): Greenland’s glaciers are dumping twice as much ice into the Atlantic Ocean now than 10 years ago because glaciers are sliding off the land more quickly, researchers said yesterday.
This could mean oceans will rise even faster than forecast, and rising surface air temperatures are to blame, the researchers report in today’s issue of the Science magazine.
Glaciers around the world are disappearing quickly, several researchers told a meeting of the American Association for the Advancement of Science, which publishes Science.
“Greenland is probably going to contribute more and faster to sea level rise than predicted,” Eric Rignot of Nasa’s Jet Propulsion Laboratory at the California Institute of Technology said.
Between 1996 and 2006, the amount of water lost from Greenland’s ice sheet has more than doubled from 90 cubic km to 220 cubic km a year, Rignot said.
“One cubic km is the amount of water Los Angeles uses in a year. Two-hundred cubic km of water is a lot of fresh water,” Rignot said.
Other experts agreed that this could mean scientists have underestimated how much the sea level will rise in the future as the planet warms.
“At 1.7 million square km, up to 3 km thick and a little smaller than Mexico, the Greenland Ice Sheet would raise global sea level by about 7 meters if it melted completely,” Julian Dowdeswell of the Scott Polar Research Institute at Britain’s Cambridge University wrote in a commentary in Science.
The study did not explore what is causing the rising air temperatures in Greenland, but most scientists agree that human activity, notably the burning of fossil fuels, is playing an important role in global warming.
Rignot and Pannir Kanagaratnam of the University of Kansas used satellite data to track the movement of Greenland’s glaciers, which slide slowly down to the sea and deposit ice. They calculated that Greenland contributes about half a millimetre to the annual 3 mm rise in global sea levels.
Since 1996, southeast Greenland’s glaciers have been flowing more quickly and since 2000, glaciers farther north have also sped up.
One glacier that once was stable is now disappearing at the rate of 14 km a year, Rignot said. Rising air temperatures are clearly a factor, the researchers told the meeting. “This is clearly a result of warming around the periphery of Greenland,” Rignot said.