Carbon Dixoide emissions receive most of the ink in climate change discussions.
Joe Romm, over at Climate Progress posted on most of the recent publications related to Methane emissions in the Arctic, as they related to climate change in a piece called, "Science stunner: Vast East Siberian Arctic Shelf methane stores destabilizing and venting".
http://climateprogress.org/2010/03/04/science-nsf-tundra-permafrost-methane-east-siberian-arctic-shelf-venting/Among the many points the piece makes, along with its extensive documentation:
"Scientists learned last year that the permafrost/permamelt contains a staggering “1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere,” much of which would be released as methane. Methane is is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years!"
and..."The must-read National Science Foundation press release (click here), warns “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.” The NSF is normally a very staid organization. If they are worried, everybody should be."
http://greennature.com/article283.html">Methane, Permafrost and Climate Change makes a similar case, adding additional resources.
One point made in the article,
One of the most recent articles in EOS, a journal of the American Geophysical Union, says four methane emissions research questions remain unanswered.
1. What is the size of the permafrost carbon pool?
2. Which fraction of this pool will be converted to methane upon thaw?
3. Which fraction of the permafrost carbon pool will thaw under anaerobic versus aerobic conditions?
4. What is the role of methane oxidation in controlling methane emissions?