The disappearing Greeland ice sheet: Pearl Harbor for the world

by Robert Nagle on 8/5/2009

in global warming

Sharon Begley on the amount of permafrost in Greenland:

Scientists have long known that permafrost, if it melted, would release carbon, exacerbating global warming, which would melt more permafrost, which would add more to global warming, on and on in a feedback loop. But estimates of how much carbon is locked into Arctic permafrost were, it turns out, woefully off. "It’s about three times as much as was thought, about 1.6 trillion metric tons, which has surprised a lot of people," says Edward Schuur of the University of Florida. "It means the potential for positive feedbacks is greatly increased." That 1.6 trillion tons is about twice the amount now in the atmosphere. And Schuur’s measurements of how quickly CO2 can come out of permafrost, reported in May, were also a surprise: 1 billion to 2 billion tons per year. Cars and light trucks in the U.S. emit about 300 million tons per year.

Finally, a kicker:

Carlson vows that IPY will finish its Arctic assessment in time for the meeting, and one conclusion is already clear. "A consensus has developed during IPY that the Greenland ice sheet will disappear," he says.

Begley explains why the commitment to limit temperature increases to 2 degrees C is a mirage:

the G8, led by Europe, has vowed to take steps to keep global warming below 2 degrees Celsius by reducing CO2 emissions. We’re now at 0.8 degree. But the amount of CO2 in the atmosphere is already enough to raise the mercury 2 degrees. The only reason it hasn’t is that the atmosphere is full of crap (dust and aerosols that contribute to asthma, emphysema, and other diseases) that acts as a global coolant. As that pollution is reduced for health reasons, we’re going to blast right through 2 degrees, which is enough to ex-acerbate droughts and storms, wreak havoc on agriculture, and produce a planet warmer than it’s been in millions of years. The 2-degree promise is a mirage.

For more background, see Joe Romm’s excellent 4 part report about permafrost in the tundras: Part 1, Part 2, Part 3, Part 4.

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