Scientists sound alarm on Arctic ice cap

Satellite data for the month of June shows Arctic sea ice shrunk to a record low for the month, raising concerns about climate change, coastal erosion, and changes to wildlife patterns.

The National Snow and Ice Data Center in Boulder, Colo., uses remote sensing imagery to survey ice cover at both poles.

• INDEPTH: Arctic climate change

The centre had said 2002 was a record low year for sea ice cover in the Arctic, since satellite observations began in 1979. There's evidence that may have been the lowest annual coverage in a century.

"It actually melted back farther than normal pretty much everywhere around the Arctic," said Walt Meier of the centre. "Where it's been retreating the most has been north of Alaska and north of eastern Siberia."

Meier said the amount of ice that covered the Arctic Ocean this June shrank by a record six per cent below the monthly average.

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"June is really the first big [month] of melt in the central Arctic Ocean and so it's an indication that the melt is progressing faster than normal," he said. "When you start melting the ice, you're leaving the open ocean there, which absorbs much more solar energy and so it tends to heat up even more."

Less sea ice means more moisture in the air and more rain. It also leads to an increase in coastal erosion since the ice isn't there to buffer the shoreline from waves.

Meier said the ice has retreated almost everywhere in the Arctic except for a small area in the East Greenland Sea.

Prof. Andrew Derocher, a polar bear biologist at the University of Alberta in Edmonton, said less sea ice could also shorten the feeding time for polar bears and bring more of them into northern communities.

"It may mean that they're going to have to be particularly careful and on the lookout for more bears than they might normally find in some of the areas where they're camping during the summer until the ice comes back," Derocher said.

The National Snow and Ice Data Center said Arctic sea ice usually recovers in the winter time, but researchers have noticed ice has begun to decline in that season as well.