Tuesday, September 2, 2008

Methane bubbles through the tundra

by Fester: The major problem with most of the climate change models' results has been the models' underestimation of nasty positive feedback loops. This means problems are showing up in the real world faster, bigger or both than what the models would indicate. Via a Fistful of Euros is a report of a highly probable positive feedback mechanism that is starting to occur in Siberia:

Methane, a potent greenhouse gas, is leaking from the permafrost under the Siberian seabed, a researcher on an international expedition in the region told Swedish daily Dagens Nyheter on Saturday.... Methane is more than 20 times more efficient than carbon dioxide in trapping solar heat. Scientists fear that global warming may cause SiberiaĆ¢€™s permafrost to thaw and thereby release vast amounts of methane into the atmosphere. The effects of global warming are already most visible in the Arctic region.

Siberia, and the other permafrost regions of the world are massive methane sinks that hold roughly 10 gigatons of methane. If all of this was released, it would be roughly the equivilant of 200 gigatons of carbon dioxide. The global carbon dioxide emissions in 2004 were roughly 28 gigatons. So if the permafrost releases all of its methane, it would be the equivalent of another 7 years of carbon dioxide being added to the atmosphere in addition to the baseline carbon that is continuously being added.

Given that negative impacts are being seen today, adding most of a decade's worth of additional carbon to the baseline without any impact on trend would make this very bad news.

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