August 31, 2009

Identifying Arctic Methane’s Climate Risk Factors

Researchers are warning of a slow seepage of methane gas from under the Arctic permafrost, which could be very dangerous to the Earth's future climate.

"On a calm day, you can see 20 or more 'seeps' out across this lake," Canadian researcher Rob Bowen told the Associated Press from his boat on the Mackenzie River Delta.

Bowen said it is essentially pure methane bubbling up from the surface, which spells trouble for the earth's climate, experts say.

Temperatures in the Arctic have increased by more than 2.5 Celsius (4.5 Fahrenheit) since 1970. The warmer temperatures are causing the ice and snow to melt faster and deeper than before - at a rate of 1.5 inches a year.

The Intergovernmental Panel on Climate Change (IPCC) has said it sees no end in sight for the rising temperatures. The UN-sponsored group has predicted that temperatures would rise an additional 13 degrees Fahrenheit.

In 2007, researchers in Russia warned that the rising temperatures and rising methane in the Arctic would be disastrous for the planet.

And while many experts say that large-scale seepage of methane gas takes centuries to unfold, the Russian survey has inspired six US labs to study the impacts of a rising rate of methane release.

The gases lie trapped deep below layers of permafrost. A team of researchers led by the University of Florida's Ted Schuur found that more carbon exists in the top 10 feet of permafrost than in the earth's atmosphere.

"It's safe to say the surface permafrost, 3 to 5 meters, is at risk of thawing in the next 100 years," Schuur said.

"Many factors are poorly studied, so we're really doing frontier science here," Geological Survey of Canada scientist Scott Dallimore told the Associated Press.

"There is a very large storehouse of greenhouse gases within the permafrost, and if that storehouse of greenhouse gases is fluxing to the surface, that's important to know. And it's important to know if that flux will change with time."

Dallimore used underwater robots to determine where methane gas appeared to be leaking from the seabed.

His team is also watching how the seeps change throughout the seasons, using listening devices.

Dallimore is also working alongside German and Canadian specialists in aerial surveying to study "hot spots" using spectrometric imagery that will identify certain chemicals from overhead.

"I and others are trying to take field observations and get it scaled up to global models," Schuur told the AP.

"From some 400 boreholes drilled deep into the tundra worldwide, "we see historic warming of permafrost. Much of it is now around 2 below zero (28 F)."

Image Courtesy NASA


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