Environmentalists and some of the more eccentric members of the scientific community like to allude to the possibility that the Arctic permafrost will melt, releasing a methane time bomb into the atmosphere which will inevitably end in runaway global warming and an apocalypse. There is even an Artic Methane Emergency Group featuring our old friend Peter Wadhams, among others, and with headlines along the lines of "The Arctic is rapidly heading for meltdown".
It's a good story, and no doubt good for business too, but unfortunately somebody has gone and spoiled it all:
[N]ew research led by Princeton University researchers and published in The ISME Journal in August suggests that, thanks to methane-hungry bacteria, the majority of Arctic soil might actually be able to absorb methane from the atmosphere rather than release it. Furthermore, that ability seems to become greater as temperatures rise.