One of the most worrying positive feedbacks of our current climate change lies deep in the Arctic permafrost and the ocean – methane hydrates. Methane loosely bonds to water, which freezes and lies stable…..until it melts. When it gets warm enough, the methane breaks apart from the water and is released into the atmosphere, or is dissolved in the ocean and then slowly released.
There is an enormous amount of methane in the form of hydrates up north – using its GWP, enough to “double” the amount of CO2 (even if it doesn’t all convert to CO2), if I remember correctly. This feedback is not included in climate models, as nobody really knows when or at what point huge amounts of methane could be released.
Unfortunately, we have evidence that it’s starting to begin. CORDIS and BBC report that a study in Geophysical Research Letters has discovered methane plumes rising from the ocean floor. Right now the methane is dissolving in the water, but we don’t know whether or when it’ll reach the atmosphere. Even if the methane stays dissolved, the acidity of the ocean will increase, which can damage marine life. Even if this begins as only an impact, not a feedback, the Arctic is stressed out enough as it is.
I didn’t expect to hear news like this for quite a few years. As one of the authors says, “Our survey was designed to work out how much methane might be released by future ocean warming; we did not expect to discover such strong evidence that this process has already started.”
Reminds you a bit of Larsen-B, doesn’t it?
ClimateSight 
In my day job, about 18 months ago, I remember reading about an unexplained spike in methane readings in 2006 after years on a plateau… And I held my breath. Then about a year ago, Russian scientists had discovered roiling plumes of methane welling up along the Siberian sea, and it made me feel sick to my stomach. It seemed like a smoking gun.
I expect we’ll see more about methane in the coming months and yes, it scares the bejesus out of me.
With the mounting evidence from so many sources, I don’t see how deniers can hold to their credo. And yet this is just one more stuy to file under alarmism, to be explained by natural causes.
To me this is the sleeping giant issue. CH4 levels have only started climbing a little in the last few years after levelling off for about a decade. Some have suggested the plateau may have been due to the collapse of the Soviet Union and efforts to cap landfills in the late 90’s. However, recent studies highlighting the amount of carbon stored below the Arctic as bothe Methane Clathrates/Hydrates and defrosting organic matter and the early reports of sea and land based Methane emissions in the Arctic suggest this is the Climate Change issue to watch. It isn’t serious yet but if emission levels start to climb significantly then Methane could easily start to match the impact of new Human emissions. If the arctic is thawing to this extent when AGW is only at 0.8 globally, what will the thawing be like in decades to come as warming in the pipeline comes through. As you said, Scary Stuff.
It was in the literature, but I do not see anything in the IPCC that says, “Stop warming the oceans before you melt the clathrates! And, by the way, you are basically out of time!” That should have been in big red letters on the cover of the last IPCC Summary for Policy Makers!
Agreed!
David Archer wrote quite a detailed article about this on Real Climate back in 2005.
Basically it didn’t get much coverage in AR4 because the science was (and still is) so uncertain. The IPCC is, after all, all about consensus.
Still scary, though.
You really should tell that to the skeptics who get mad because their views aren’t represented in the IPCC. Some of the scariest, most extreme stuff is eliminated as well. The idea of the IPCC is to represent what is agreed on, not every single thing that anyone says.
I do try to. :)
But of course they don’t listen.