USGS/UAA Study - Arctic Now Traps 25% Of Atmospheric Carbon, But This, Too, Could Change Rapidly

[hatrack]

he arctic could potentially alter the Earth's climate by becoming a possible source of global atmospheric carbon dioxide. The arctic now traps or absorbs up to 25 percent of this gas but climate change could alter that amount, according to a study published in the November issue of Ecological Monographs.

In their review paper, David McGuire of the U.S. Geological Survey and the University of Alaska at Fairbanks and his colleagues show that the Arctic has been a carbon sink since the end of the last Ice Age, which has recently accounted for between zero and 25 percent, or up to about 800 million metric tons, of the global carbon sink.

On average, says McGuire, the Arctic accounts for 10-15 percent of the Earth's carbon sink. But the rapid rate of climate change in the Arctic - about twice that of lower latitudes - could eliminate the sink and instead, possibly make the Arctic a source of carbon dioxide. "This study is another example of the important role played by USGS and its partners in providing the scientific research that must be the backbone of any actions related to climate change," said Secretary of the Interior Ken Salazar.

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We don't understand methane very well, and its releases to the atmosphere are more episodic than the exchanges of carbon dioxide with the atmosphere," says McGuire. "It's important to pay attention to methane dynamics because of methane's substantial potential to accelerate global warming." But uncertainties still abound about the response of the Arctic system to climate change. For example, the authors write, global warming may produce longer growing seasons that promote plant photosynthesis, which removes carbon dioxide from the atmosphere.

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http://www.terradaily.com/reports/Arctic_Traps_25_Percent_of_World_Carbon_But_That_Could_Change_999.html

[XemaSab]

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