STOCKHOLM — The ice of Greenland and the rest of the Arctic is melting faster than expected and could help raise global sea levels by as much as 5 feet this century, dramatically higher than earlier projections, an authoritative international assessment says.
The findings "emphasize the need for greater urgency" in combating global warming, says the report of the Arctic Monitoring and Assessment Program, the scientific arm of the eight-nation Arctic Council.
The warning of much higher seas comes as the world's nations remain bogged down in their two-decade-long talks on reducing emissions of carbon dioxide and other greenhouse gases blamed for global warming.
Rising sea levels are expected to cause some of global warming's worst damage — from inundated small islands to possible flooding of New York City's subways. Oceans will not rise uniformly worldwide, because of currents, winds and other factors, but such low-lying areas as Bangladesh and Florida will likely be hit hard.
The new report, whose executive summary was obtained by the Associated Press, is to be delivered to Secretary of State Hillary Rodham Clinton and foreign ministers of the other seven member nations at an Arctic Council meeting next week in Greenland. It first will be discussed by some 400 international scientists at a conference this week in Copenhagen, Denmark.
Drawing on improved research techniques and recent scientific papers, the AMAP report updates forecasts made by the U.N.' s expert panel on climate change in its last major assessment in 2007.
The melting of Arctic glaciers and ice caps, including Greenland's massive ice sheet, is projected to help raise global sea levels by 35 to 63 inches by 2100, AMAP said, although it noted that estimate was highly uncertain.
That's up from the 2007 projection of 7 to 23 inches by the U.N. panel. The U.N. group had left out the possible acceleration of melting in Greenland and Antarctica, saying research on that hadn't advanced sufficiently for the mid-2000s. The U.N. estimate was based largely on the expansion of ocean waters from warming and the runoff from melting land glaciers elsewhere in the world.
Now the AMAP assessment finds that Greenland was losing ice in the 2004-09 period four times faster than in 1995-00.
In addition, the cover of sea ice on the Arctic Ocean is shrinking faster than projected by the U.N. panel, threatening the long-term survival of polar bears and other ice-dependent species. Summer ice coverage has been at or near record lows every year since 2001, said AMAP, predicting the ocean will be almost ice-free in the summer in 30 to 40 years.
Arctic temperatures in the past six years were the highest since measurements began in 1880, and "feedback" mechanisms are believed to be speeding up warming in the far north.
"The observed changes in sea ice on the Arctic Ocean, in the mass of the Greenland ice sheet and Arctic ice caps and glaciers over the past 10 years are dramatic and represent an obvious departure from the long-term patterns," AMAP said.