Arctic Ice Melt 2nd Greatest Ever Seen

This map shows the extent of Arctic sea ice, in white, at the end of the 2011 melt season on Sept. 9. The orange line shows the median extent of ice at this point of the year in recent decades.

Photo: NSIDC

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The melting of Arctic sea ice this year has nearly set a new record, and scientists with the National Snow and Ice Data Center say the extent of ice now, at the end of the melt season, is the second lowest ever recorded. While the melting appears to be over for the year, past years have continued melting for another week or two into September, and 2010 saw a double dip at this point in the season; the announced end to the melt season is therefore considered preliminary.

The Arctic melt is considered a bellwether of climate change, since the Arctic is warming faster than other parts of the globe. (Worldwide, August ranked as the eighth warmest since record-keeping began in 1880.) While loss of sea ice doesn't directly affect sea levels (imagine ice cubes melting in a glass of water) it can release the "cork" holding back glaciers, and the warmer water can contribute to melting on land, both of which can cause sea levels to rise. Projected sea-level rise from climate change is one direct and costly threat to taxpayers in coastal cities around the world. (Imagine the damage from storm surge from a Hurricane Irene if sea levels were a foot or two higher.) Weather patterns and ocean ecosystems supporting important commercial fish around the world are also influenced by the Arctic.

The end of the melt season coincides with a decision by the Environmental Protection Agency to delay the nation's first national regulations aimed at curbing carbon dioxide emissions from the largest single source, coal-fired power plants. Environmentalists are angry that the Obama Administration, after making some historic strides to address global warming through tighter fuel economy standards, among other initiatives, is now bowing to pressure from industry and political opponents in weakening environmental protections.

Comparing the 2011 melt to the record 2007 melt shows some significant worrying signs, according to the National Snow and Ice Data Center analysis. Both melt seasons ended with ice covering approximately one-third less of the Arctic than average. But while 2007 was marked by particularly warm weather and wind patterns that speed melting, 2011 was overall an typical year for weather. And yet the ice still melted.

Imagine an expanse of ice covering all U.S. states west of the Mississippi. Add on the Great Lakes states of Wisconsin, Illinois, Indiana, Michigan and Ohio. And then tack on Mississippi. That's how much covered the Arctic, on average, at the end of the melt season, from 1979 to 2000. Now imagine that ice melting so that it covers only the Pacific Northwest and adjacent states - Washington, Oregon, California, Montana, Wyoming, Idaho, Nevada and Utah. That's the amount of ice left in the Arctic after this year's melt season.

That's good news for the shipping and oil industries, which can exploit open waters. Environmentalists warn that oil drilling in the Arctic is inherently risky because of the conditions and fragility of the ecosystem, and because a cleanup would be far more difficult than one in warmer waters closer to emergency response infrastructure. And, unlike in the warm water of the Gulf of Mexico, oil spilled in the icy Arctic won't break down and dissipate quickly.

Now imagine you're a polar bear or a Pacific walrus that relies on ice to hunt, to rest after hunting and to otherwise exploit the relative riches of the warm season before the long cold, sunless winter sets in. You suddenly have a lot more water to swim through, which takes a lot more energy and leaves you less able to survive the winter.

That's primarily why both species are among the Arctic denizens to be designated for protection under the Endangered Species Act. Lack of ice has left walruses nowhere to go but land, and they've hauled out by the thousands on land, leaving young vulnerable to trampling by the masses of big adults. This U.S. Geological Survey video illustrates the amazing wildlife display, which was rarely if ever seen before the sea ice started melting to this degree:

Polar bears may have it even worse, as this World Wildlife Fund video illustrates:

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