Arctic Sea Ice at Lowest Point in 800 Years

Arctic Sea Ice in March 1998

Photo: NASA

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The rate of melting in the Arctic this summer is trending toward another record or near-record low, according to the latest satellite data. While the melt season doesn't end until September, leaving plenty of variability to come, the long-term trend in Arctic ice is clear, and clearly pointing in one direction.

Scientists have been increasingly alarmed at the rate of melting in the Arctic, which leaves less thick, perennial ice, which in turn leads the restored winter ice more vulnerable to melting each summer. As more dark water replaces reflective ice, more of the sun's heat is absorbed, leading to more melting. The pace of melting in the Arctic has exceeded even the worst-case scenarios presented by United Nations scientists studying global warming. The situation could get rapidly worse if, as a recent study indicates, there's far more methane trapped in permafrost than previously thought; when the permafrost melts, that powerful greenhouse gas will flood the atmosphere, accelerating global warming further.

As the Arctic goes, so will the rest of the world -- eventually. That's the bottom line. The changes we're witnessing in the Arctic -- their scale, their consequences for Arctic wildlife like the polar bear and walrus, and their tendency to reinforce warming trends -- are leading-edge indicators of what we can expect worldwide. Not only because the Arctic is the world's "air conditioner," as is often said, but because it's just a little more sensitive than other regions to temperature change. Of course, melting ice, in many cases, means rising sea levels.

But even with those dire warnings, scientists have largely relied on comparative data that stretches back only a few decades -- to the dawn of the satellite era.

No longer.

A new analysis by a geophysicist at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen, using everything from ice cores and tree rings to the logs of 16th century ocean voyages, concludes that the extent of ice in the Arctic is lower today than at any time in the last 800 years. The new record stretches back to the 13th century, when Genghis Khan was spreading war (and his seed) across Asia.

One would hope data like this -- documenting the almost unfathomable changes we've brought on the Earth in just a couple hundreds years of burning fossil fuels -- will bring political urgency to the G8 Summit on July 9, where President Obama will convene the world's top carbon dioxide polluters. (World Wildlife Fund's latest scorecard on the steps G8 nations have taken to curtail global warming does not give high marks.) He has been given political support from the House of Representatives, which passed the first-ever U.S. regulation to cap-and-trade carbon (it still must pass the Senate before it could become law) as part of a sweeping energy bill last week. Critics, however, have pointed out that even that historic action will not save the world as we know it.

Meanwhile, climate science deniers continue to obscure the facts: Georgia Republican Congressman Paul Broun reprising -- to depressing applause during debate on the climate bill -- Sen. James Inhofe's famous line about global warming being the "greatest hoax perpetrated on the American people"; and Exxon-Mobil being exposed for continuing to fund groups that actively obscure the climate science consensus.

The promising thing: After eight years during which the Bush Administration seemed to bend over backwards to ignore scientific conclusions about climate change, the Obama Administration is promising to listen to scientists as it not only crafts domestic policy but engages with other world leaders.

What can you do? You can start by joining The Daily Green's carbon rally team, and pledging to do your part to reduce your carbon footprint. You can also start with these 15 resolutions anyone can do, courtesy of The Daily Green's partner, the Natural Resources Defense Council.

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