Climate change, global warming, AGW -- whatever you want to call it, whatever you think the cause of it is, I don't care. It's happening. The planet has warmed significantly in the last few decades, and coincidentally, the human emmissions of carbon dioxide (and other greenhouse gases) has also increased at a tremendous rate.
I'm not going to argue one way or another about the causes of it all. I personally think it's a combination of a lot of stuff (yes, including human actions). But the effects are going to be significant and potentially devastating to civilization as we know it. Changing weather patterns, rising sea levels, disruption of crop cycles, etc will all create chaos in the world as we know it.
But what happens if the methane bursts loose?
It looks like it might be starting, and that's a bad thing. Carbon dioxide's a greenhouse gas, but not a very efficient one. Methane, on the other hand, is a blockbuster. There is enough methane trapped in the frozen hydrates beneath the Siberian sea and other oceanic shelf systems to more than double the atmospheric carbon if it all came out. And it's starting to melt and leak.
Right now, things are not perfect, but we can manage. But if the methane breaks out it will start a feedback chainreaction of warming the permafrost, releasing even greater amounts of methane, causing even more warming, etc. And then all that excess carbon has to go somewhere -- and it will go into the oceans.
Great idea, right? Wrong! That much carbon forced into the oceans will increase the acidity levels to the point of destroying the carbonate shells of the sea critters - including the diatoms which are at the bottom of the overall oceanic food chain. And what happens, boys and girls, when the bottom drops out of a food chain? Starvation and death all the way to the top -- which means all of the world's humans, too.
Yup, anthropogenic global warming might be wrong, but whatever the cause it's getting worse, and if we can't slow or stop the rise in temps soon, it won't matter a bit who caused it - we won't be here to argue about it anyway.