A few weeks ago there was a discussion here about methane hydrate being released into the atmosphere and spseeding up global warming. Here is more information that someone sent to me:
http://climateprogress.org/2010/03/04/science-nsf-tundra-permafrost-methane-east-siberian-arctic-shelf-venting/ and http://climateprogress.org/2007/09/20/a-methane-feedback-from-the-past-strikes-again/
