Arctic sea ice melt comes close

WASHINGTON - Crucial Arctic sea ice this summer shrank to its second lowest level on record, continuing an alarming trend, scientists said Tuesday.

The Advanced Microwave Scanning Radiometer (AMSR-E), a high-resolution passive microwave Instrument on NASA's Aqua satellite shows the state of Arctic sea ice on September 10 in this image released September 16, 2008. Arctic sea ice melted to its second-lowest level this summer, rising a bit from 2007's record but still showing a strong downward trend that is a key symptom of climate change, U.S. scientists said Tuesday. The ice slipped to its minimum extent for 2008 on September 12, when it covered 1.74 million square miles (4.52 square km), and now appears to be growing as the Arctic starts its seasonal cool-down, the National Snow and Ice Data Center said.

The ice covered 1.74 million square miles on Friday, marking a low point for this summer, according to NASA and the National Snow and Ice Data Center in Boulder, Colo. Last summer, the sea ice covered only 1.59 million square miles, the lowest since record-keeping began in 1979.

Arctic sea ice, which floats on the ocean, expands in winter and retreats in summer. In recent years it hasn't been as thick in winter.

This Radarsat-1 image of the Ward Hunt Ice Shelf in northorn Canada obtained July 29, 2008 shows the network of cracks threatening the integrity of the ice shelf. Two ice shelves in Canada's far north have lost massive sections since August while a third ice shelf now is adrift in the Arctic Ocean, said researchers Wednesday who blamed climate change.

Sea ice is crucial to worldwide weather patterns, both serving as a kind of refrigerator and reflecting the sun's heat. Given recent trends, triggered by man-made global warming, scientists warn that within five to 10 years the Arctic could be free of sea ice in the summer.

Even though the sea ice didn't retreat this year as much as last summer, "there was no real sign of recovery," said Walt Meier of the snow and ice data center. This year was cooler and other weather conditions weren't as bad, he said.

"We're kind of in a new state of the Arctic basically, and it's not a good one," Meier said. "We're definitely sliding towards a point where the summer sea ice will be gone."

source: news.yahoo.com