|
The hunt for GHG emissions in the Arctic
Alan Bailey Petroleum News
As global climate change warms the Arctic, could vast quantities of carbon dioxide and methane, both thought to be potent greenhouse gases, be released from frozen organic material, or from disassociating methane hydrates known to exist under the Arctic tundra and the Arctic Ocean?
To make a start on answering this question, scientists from the National Oceanic and Atmospheric Administration Earth System Research Laboratory have teamed with the U.S. Coast Guard to fly air-sampling devices over Alaska, using the Coast Guard C-130 aircraft that is based in Kodiak.
In March NOAA scientists replaced one of the Coast Guard’s C-130’s windows with a plate with air inlets leading to onboard instruments which measure the amount of methane, carbon dioxide and ozone in the air, NOAA said.
“Scientists will search for natural sources of methane and carbon dioxide — the two most important heat-trapping gases — as well as methane sources from human activities, such as oil drilling in Prudhoe Bay,” NOAA said Aug. 24. “Gathered over three seasons, the data will help NOAA map out natural emissions sites, estimate their outflow and set benchmarks for future changes in a warming world.”
Clues from the south “North of the Brooks Range, the tundra is not yet melting, but south of the range, partial melting is already occurring,” said Colm Sweeney of the Earth System Research Laboratory. “The south will give us clues to what’s likely to happen north of the range in the coming years.
“… It’s important to locate natural sources and measure how much methane and carbon dioxide are being released now so we can watch for signs of increasing emissions. Methane is 25 times more powerful than carbon dioxide as a greenhouse gas, though its lifetime in the atmosphere is significantly shorter.”
Research has documented large “bubbles” of methane near Arctic lakes. And research vessels in the Arctic Ocean have observed methane venting from the ocean floor, although no one knows whether this phenomenon is a recent development or something that has been happening for a long time, NOAA said.
“Recent observations could be isolated cases or part of a vast regional change in emissions that could accelerate climate warming to a more dangerous pace. We don’t know yet. We’re eager to find out,” Sweeney said. “… So far profiles north of the Brooks Range indicate significant enhancements in methane emissions near the surface, but it’s uncertain whether those are local emissions from human activities or outgassing from natural sources.”
| 