By BOB WEBER The Canadian Press
The ocean area covered by Arctic sea ice last summer was as low as it's ever been, according to a newly released study.
And the rate of melting gets faster every year, suggesting that a self-perpetuating warming cycle predicted by climate change models is already at work, said the data released by the main American centre for ice studies.
"Sea ice is not doing well and it has not recovered and it doesn't appear that it is going to recover," said Mark Serreze of the National Snow and Ice Data Centre in Boulder, Colo.
Global warming is so far having its most dramatic effects in the North, so
Arctic sea ice is considered to be one of the most important indicators of climate change.
The ice also plays an important role in global climate because it affects the delicate balance of ocean salinity and temperature.
As well, it's crucial for everything from polar bears who depend on the floe edge for much of th~ir hunting to shippers on the lookout for more efficient routes between ports.
Serreze's group uses data from satellites and weather stations to monitor the Arctic ice cap. Every fall, around mid-September, the centre releases a snapshot at the end of the summer melting season of what is called the sea ice minimum.
This year's minimum, which occurred Sept. 14, showed the fourth-lowest extent of sea ice on a single day in 29 years of satellite records.
When the entire month of September was considered, the amount of ocean either ice-covered or ice-choked was the second lowest on record. Only 2005
Dark, open seas absorb the sunlight that white ice would have reflected, so warming speeds up the more ice melts. As well, open seas generate more cloud cover, blanketing the ocean during the long Arctic winter and preventing temperatures from falling to normal levels.
"These feedbacks are starting to kick in," said Serreze. "I'm not terribly optimistic about the future of the ice."
If current trends hold, Arctic ice will be largely gone by 2060 - a full decade earlier than the most pessimistic previous predictions, he suggested.
Most of the ice losses are concentrated off Russia's Siberian coast.
Winds and currents tend to pW?q, h:e into Canada's High Arctic islands, so coverage there is only shrinking at 1.6 per cent per a decade, said John Falkingham, chief forecaster for the Canadian Ice Service.
"We expect that the last ice that will remain in the Arctic Ocean will be in Canadian waters," Falkingham said. "The Northwest Passage will be the last place the ice will melt out of."