Tuesday, May 27, 2008

Methane rise points to Arctic wetlands

BBC: Higher atmospheric levels of the greenhouse gas methane noted last year are probably related to emissions from wetlands, especially around the Arctic. Scientists have found indications that extra amounts of the gas in the Arctic region are of biological origin.

Global levels of methane had been roughly stable for almost a decade. Rising levels in the Arctic could mean that some of the methane stored away in permafrost is being released, which would have major climatic implications. The gas is about 25 times more potent than carbon dioxide as a greenhouse gas, though it survives for a shorter time in the atmosphere before being broken down by natural chemical processes.

Indications that methane levels might be rising after almost a decade of stability came last month, when the US National Oceanic and Atmospheric Administration (Noaa) released a preliminary analysis of readings taken at monitoring stations worldwide. Noaa suggested that 2007 had seen a global rise of about 0.5%. Some stations around the Arctic showed rises of more than double that amount….

Model of a methane molecule by "King of Hearts," Wikimedia Commons, under the terms of the GNU Free Documentation license, Version 1.2

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