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Arctic methane seeping through thawing permafrost fuels warming

Katie Medred

The University of Alaska Fairbanks released a report Monday on how methane in the Arctic may add to a warmer planet.

According to a recently published study by UAF researcher Katey Walter Anthony, geologic methane seeps in Alaska may contribute about 250,000 metric tons of the gas into to the atmosphere each year.

The study, the first of its kind, found that widespread terrestrial sources of geologic methane in the Arctic is contributing heavily to receding glaciers and may endanger what’s known as the “cryosphere cap.”

Previous research has found that warming permafrost releases methane as the ground softens and decaying organic matter thaws. Walter Anthony’s research is the first to confirm the source of geologic methane emissions. Methane is escaping through fissures in the Earth’s crust, adding on to the organic methane production above ground. According to Walter Anthony's findings underground geologic sources of the greenhouse gas roughly equal the above-ground organic sources.

It’s not unusual to see methane released in the Arctic, but excessive leaking is not a good sign. In surveys across Alaska during the winters of 2008 through 2010 Walter Anthony’s team noted rapidly rising methane plumes creating large open patches in frozen bodies of water. Like the leaks in the Arctic Ocean, these lake fissures are exhaling methane gas terrestrially. This is a somewhat disheartening find because methane contributes to global warming and is considered more potent than carbon dioxide.

The cryospher cap is ground cover made up of glaciers, permafrost and ice sheets. Together, the cover acts as a lid, trapping methane gases from coal beds and natural gas deposits beneath. Without the protective blanket, the underground gasses escape into the atmosphere. The more the cryospher gap recedes, the more methane escapes into the atmosphere, which fuels the cycle.

“In a warmer world,” according to Walter Anthony, “thawing permafrost and wastage of glaciers and ice sheets could lead to a significant transitional degassing of subcap methane,” which would -- you guessed it – stimulate the global temperature.