Quick summary: Two expeditions to the Arctic have, in the last few days, seen methane gas bubbling up through the ocean. It is apparently leaking out from below the permafrost layer on the bottom. As of this moment it is anyone's guess how long this has been going on for, but it could be a new phenomenon due to the melting of the permafrost on the bottom of the arctic ocean.
References: Article in English in "The Independent": http://www.independent.co.uk/environment/climate-change/exclusive-the-methane-time-bomb-938932.html http://tinyurl.com/3n4tdy Article (in French) to which I was originally directed; ran across the reference in another newsgroup: http://www.futura-sciences.com/fr/news/t/climatologie-1/d/methane-arctique-le-retour-de-la-bombe-climatique_16891/ http://tinyurl.com/3h77qt
