Peter Sinclair has done some nice work to clarify the famous Methane Bomb thing.
Briefly, the Methane Bomb is where methane trapped on the floor of the Arctic ocean gets out in large quantities because it is warm. This makes more warming. So, more of this Methane comes out, causing it to get warmer, then this cycle keeps up for a while and in short order civilization collapses and we all die.
It turns out that the science DOES NOT SUPPORT A METHANE BOMB OR ANYTHING LIKE THAT. It just doesn't. Unfortunately this has become a point of contention among people who are truly, seriously, concerned about climate change. It is a little like Ebola. If you take Ebola seriously and are approproately afraid of it, it seems, you are required to believe that it has already "gone airborne" and civilization will end and we will all die (Ebola has not gone airborne and will not go airborne). With Methane, if you truly love the planet then you are required to believe in the Methane Bomb. Even if it isn't for real. And, it isn't for real.
Dr. Carolyn Ruppel is one of the senior scientists who study Arctic Methane (and bottom-of-the-ocean Methane in general). In two videos put together by Peter Sinclair, she goes into significant detail about this problem.
This is the end of the old Arctic Methane discussion and the beginning of the new discussion.
Both really good interviews.
Interestingly, I've been saying for a while that we never hear from the other side of the debate ("other" meaning opposite from the deniers). We usually hear the deniers and the scientists. Now we're starting to hear from what I've heard Richard Alley refer to as "the screaming hairy banshies."
I was trying to locate the AGU video where Alley addresses "the long tail" but I can't find it. His take, if I remember correctly was, the methane bomb idea is interesting science and contributes to uncertainties on the high side of the distribution, but, meh, probably not gonna happen anytime soon.
I haven't viewed the videos yet, will do shortly. But I have read and article this morning about methane munching microbes (http://phys.org/news/2014-10-rock-dwelling-microbes-methane-deep-sea.ht…). This all sounds like good news. I have to admit, the methane potential scares the living crap out of me.