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Study: Arctic Sea Ice at Second-lowest Level on Record

BY Admin  September 4, 2008 at 3:30 PM EDT

NSIDC image shows shrinking Arctic ice cap.

It’s now a “neck-and-neck race between 2007 and this year over the issue of ice loss,” Mark Serreze, a senior climate researcher at NSIDC said, quoted Canwest News Service.

Researchers will know in the next several weeks, once the peak of the melting season passes, whether 2008 will break the record, NSIDC said in a statement.

The North Pole melting season typically begins in mid-June, shrinking to its lowest amount by mid-September, and then grows again in winter.

According to the NSIDC, measurements taken Aug. 26 showed the Arctic ice cap was 2.03 million square miles, which fell below the 2.05 million square miles measured on Sept. 21, 2005. The amount also is 760,000 square miles below the 1979 to 2000 average.

As a sign of warming temperatures, a 19-square-mile piece of the northern ice cap — nearly the size of Manhattan — has broken away from Ellesmere Island in Canada’s northern Arctic and is now afloat in the Arctic Ocean, scientists said Wednesday. The 4,500-year-old Markham Ice Shelf had separated from the cap in early August.

“The Markham Ice Shelf was a big surprise because it suddenly disappeared. We went under cloud for a bit during our research and when the weather cleared up, all of a sudden there was no more ice shelf. It was a shocking event that underscores the rapidity of changes taking place in the Arctic,” Derek Mueller of Trent University in Ontario told the Associated Press.

Earlier this year, a 160-square-mile chunk of an Antarctic ice shelf disintegrated.

In addition, a seven-square-mile piece of the Ward Hunt shelf, which measures 170-square-miles and 130-feet-thick, fell off in August.

“Reduced sea ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer,” said Luke Copeland, director of the Laboratory for Cryospheric Research at the University of Ottawa, reported the AP. “And extensive new cracks across remaining parts of the largest remaining ice shelf, the Ward Hunt, mean that it will continue to disintegrate in the coming years.”

The U.N. Intergovernmental Panel on Climate Change said last year that temperatures in the Arctic are increasing at almost twice the global rate, according to Bloomberg News.

Much of the multi-year ice in the Arctic was lost in 2007, so at the start of this year’s melting season, the thinner, first-year ice, had a lesser chance of surviving the summer.

The receding polar ice could impact species, such as the polar bear, and ecosystems with rare microbial life, researchers contend.

The melting sea ice also has opened up the fabled shipping route, the Northwest Passage, for the past two years and likely this year as well, said Canadian Ice Service senior ice forecaster Luc Desjardins, according to Canwest News Service.

Some researchers say the reoccurring retreat of polar sea ice means the region is approaching a “tipping point” that could see the entire Arctic ice-free by summer 2030 or sooner. Previous estimates had the disappearance of Arctic ice by between 2050 and 2100.