By Stephen Leahy
“The way we’re going right now, I’m not optimistic that we will avoid some kind of tipping point.”
— Mark Serreze, senior research scientist at the National Snow and Ice Data Centre
UXBRIDGE, Canada, Mar 5, 2010 (IPS)
The frozen cap trapping billions of tonnes of methane under the cold waters of the Arctic Ocean is leaking and venting the powerful greenhouse gas into the atmosphere, new research shows.
It is not known if this may be one of the first indicators of a feedback loop accelerating global warming.
Researchers estimate that eight million tonnes in annual methane emissions are being released from the shallow East Siberian Arctic Shelf, which is equivalent to all the methane released from the world’s oceans, covering 71 percent of the planet.
On a global scale of methane emissions from the land-based sources – animals, rice paddies, rotting vegetation – the newly measured emissions from the Siberian seabed are less than two percent.
“That’s still very significant,” Natalia Shakhova, a researcher at the University of Alaska in Fairbanks, told IPS. “Before, it was assumed that this region had zero emissions.”
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Methane concentrations measured over the oceans are currently about 0.6 to 0.7 parts per million (ppm), but they are now 1.85 in the Arctic Ocean generally, and between 2.6 and 8.2 ppm in the East Siberian Arctic Shelf, an area roughly two million square kilometres in size, said Shakhova.
Shakhova, and her University of Alaska colleague Igor Semiletov, led eight international expeditions to one of the world’s most remote and desolate regions and published their results in the Mar. 5 edition of the journal Science. Continue reading