December 4, 2008

Arctic Tundra Emits Methane Even In Winter Months

On Wednesday, researchers said the arctic tundra emits the same amount of methane in winter as in the warmer months, a surprising finding that bolsters understanding of how greenhouse gases interact with nature.

Torben Christensen, a biogeochemist at Lund University in Sweden, said scientists have long known that wetlands produce large amounts of methane and had thought it unlikely that greenhouse gases escaped from beneath frozen tundra.

"Mother Nature is showing us something that is really surprising," Christensen, who led the study published in the journal Nature, said in a telephone interview.

"Nobody would expect to have loads of gas seeping out from a frozen environment."

Scientist say that is it imperative to understand all the sources for Greenhouse gases that are linked to global warming into the atmosphere.

"This study improves our understanding of how nature is connected to the climate," Christensen said. "In doing that it gives us a better understanding on how climate change is affecting arctic ecosystems."

The team stayed at Zackenberg Valley research station in northeast Greenland two months into the winter season.  This allowed them to take measurements from frozen tundra and compare the product of methane to the summer months.

They measured the atmospheric methane concentrations when the soil began freezing in late September, then they found that the levels of the greenhouse gas increased significantly as the freeze began.

The researcher team added that the findings do not change overall estimates of methane emission from high northern latitudes but do revise the view of the distribution of the greenhouse gas during the year.

"The assumption has always been that a frozen, snowed-under environment is not active in terms of a greenhouse effect," Christensen said. "It turns out this was a wrong assumption."


On The Net:

Lund University