New Data Show Rapid Arctic Ice Decline
Proportion of Thicker, More Persistent Winter Cover Is the Lowest on Record
Tuesday, April 7, 2009; Page A03
The Arctic sea ice cover continues to shrink and become thinner, according to satellite measurements and other data released yesterday, providing further evidence that the region is warming more rapidly than scientists had expected.
The data on this winter's ice buildup came on the day that international ministers gathered in Washington to address issues facing Earth's polar regions, which have been disproportionately affected by global warming. At the State Department, Secretary of State Hillary Rodham Clinton told the Antarctic Treaty Consultative Meeting and the Arctic Council that the Obama administration will press for greater action on climate change and for passage of the Law of the Sea Treaty in order to help regulate expanded human activity in a warmer Arctic, including shipping, fishing and oil exploration.
Clinton said scientists are still struggling to understand the implications of the changes, "but the research made possible within the framework of the Antarctic Treaty has shown us that catastrophic consequences await if we don't take action soon."
She added that the United States may propose that the Arctic Council's member states -- including Russia, Canada, Denmark, Norway, Sweden, Finland and Iceland -- take steps to curb shorter-lived pollutants such as methane, soot (black carbon) and ozone that compound the effects of carbon dioxide in the polar regions.
"We know that short-lived carbon forcers like methane, black carbon and tropospheric ozone contribute significantly to the warming of the Arctic," Clinton said. "And because they are short-lived, they also give us an opportunity to make rapid progress if we work to limit them."
Brooks Yeager, executive vice president for policy at the advocacy group Clean Air-Cool Planet, said such efforts could address some of the immediate effects scientists have detected at the poles. "We might be able to buy time for the Arctic system while we're solving the global problem," he said.
The satellite data released by NASA and the National Snow and Ice Data Center show that the maximum extent of the 2008-2009 winter sea ice cover was the fifth-lowest since researchers began collecting such information 30 years ago. The past six years have produced the six lowest maximums in that record, and the new data show that the percentage of older, thicker and more persistent ice shrank to its lowest level ever, at just 9.8 percent of the winter ice cover.
"We're seeing an ice cover that's younger and that's thinner as we head into summer," Walt Meier, a scientist at the National Snow and Ice Data Center, said in a telephone news conference. "It's been a pretty sharp decline."
The new evidence -- including satellite data showing that the average multiyear wintertime sea ice cover in the Arctic in 2005 and 2006 was nine feet thick, a significant decline from the 1980s -- contradicts data cited in widely circulated reports by Washington Post columnist George F. Will that sea ice in the Arctic has not significantly declined since 1979.
Scientists have begun debating how soon the Arctic will lose its summer ice altogether, with some saying it could happen as early as 2015. White House science adviser John P. Holdren told the crowd at the State Department that the total disappearance of sea ice in the Arctic "may be far, far closer" than scientists thought just a few years ago.
Meier said the gradual loss of ice is already transforming the region. "There's already impacts, in terms of the climate, in terms of the people," he said.
The loss of sea ice in the Arctic will not directly raise global sea levels, researchers said, but will contribute to an overall ocean warming that could erode the Greenland ice sheet, which would affect sea levels. The disappearance of the polar ice cap could also affect global ocean circulation patterns, and its melting has already imperiled native species such as the polar bear.
Norway's foreign minister, Jonas Gahr Stoere, painted a stark picture of the climate change in the Arctic and Antarctic regions. "The ice is melting," Stoere said. "We should all be worried."