Arctic ice melts to second-lowest level: scientists

WASHINGTON (Reuters) - Arctic sea ice melted to its second-lowest level this summer, rising slightly from 2007's record but still showing a downward trend that is a key symptom of climate change, U.S. scientists said on Tuesday.

The ice slipped to its minimum extent for 2008 on September 12, when it covered 1.74 million square miles (4.52 million square km), and now appears to be growing as the Arctic starts its seasonal cooldown, the National Snow and Ice Data Center said.

This is 33 percent below the average summer ice cover in the Arctic since satellites began measuring it in 1979 and is less than 10 percent above last year's all-time record low, said Walt Meier, a research scientist at the ice center.

"We're not as low as we were last year, which was the real mind-blowing record, but we're well below anything else we've had in the past," Meier said in a telephone interview from Boulder, Colorado.

One channel of the Northwest Passage -- a long-sought water route between Europe and Asia -- was open in both 2007 and 2008. This year also saw the opening of the Northern Sea Route, which runs through the Arctic Ocean along the Siberian coast.

The ice center said last month that there was substantial ice melt in the Chukchi Sea off the Alaskan coast in the Eastern Siberian Seas off Russia's east coast, home to one of the world's largest polar bear populations.

Because polar bears use sea ice floes as platforms for hunting seals, they are forced to swim longer distances when the ice melts, making them more likely to tire and drown.