Systems feed back on themselves. The disappearance of summer ice cover in the Arctic has received a fair amount of publicity, and it's easy to see how replacing light-reflecting snow with dark, heat-absorbing water can accelerate warming trends.
Another feedback mechanism is less well understood. Much of the ground in Alaska and the Canadian North is permafrost, which has a good deal of carbon locked up in its frozen depths, both as CO2 and in the form of an even more effective heat-trapping gas, methane.
As the climate warms in the North, melting permafrost releases both gasses. For a dramatic instance of this, courtesy Science Daily, follow below the fold.
The release of carbon dioxide associated with melting permafrost has, so far, been largely offset by increases in vegetation -- warmer weather=more plant growth. Plants don't breath in methane, however, and one must wait for it to break down into a form of carbon that the biosystem can absorb. In the meantime, whether the gas comes from cattle or sewage treatment plants or melting permafrost, it's in the atmosphere, trapping heat, and contributing to rises in atmospheric temperatures.
That's the background. I should also add that drilling for oil and gas, common across the North, releases additional carbon in both forms, regardless of whether the drilling is exploratory or it goes into production.
Last month, [University of Alaska Fairbanks (UAF)] researcher Katey Walter brought a National Public Radio crew to Alaska’s North Slope, hoping to show them examples of what happens when methane is released when permafrost thaws beneath lakes. When they reached their destination, Walter and the crew found even more than they bargained for: a lake violently boiling with escaping methane.
“It was cold, wet and windy. We... paddled out to a huge methane plume in the middle of the lake with no idea what to expect, how strong the bubbling plume would be, whether or not our raft would stay afloat, how dangerous it would be to breath the gas,” said Walter, an assistant professor in UAF’s Institute of Northern Engineering and International Arctic Research Center. “The violent streams of bubbles made the lake appear as if it were boiling, but the water was pretty cold."
The researchers were careful to note that this particular plume may be related to a methane hydrate deposit being released, rather than the gases coming directly from the permafrost itself.
That is to say that there are two sources of methane with which to be concerned. One would be methane that is locked into the permafrost itself. This comes originally from organic material -- dead plants and animals -- being digested by bacteria. As that mass is frozen, the methane is locked into it.
The other, methane hydrate, or methane ice, is more complex. Originally thought to exist only in the outer solar system, it was then discovered at depth in the ocean floor, and later found to exist in large deposits under the permafrost. It's essentially methane locked in water ice. As it melts, and as overlying layers of permafrost that lock them into place disappear, these deposits can be released directly into the atmosphere, further warming it and contributing to even more such releases.
If you have a block of this methane ice, you can set a match to it and it will burn.
Some links you may find informative are here, here, and here. Of course, the energy sector see this is a wonderful resource.
The UAF team are continuing to investigate methane hotspots in the North, to get a better sense of their connection to the disappearance of the permafrost, and of the sheer volume of gas being emitted into the atmosphere.
Here's the kicker. From Walter
“Should large quantities of methane be released from methane hydrates... in association with permafrost thaw, then we could have large sudden increases in atmospheric methane with potentially large affects on global temperatures.” [My emphasis]
Good. Great. Just peachy.
A large sudden increase. Something we can't predict or plan or compensate for. It makes me wonder what's happening to Russian permafrost, too.
I agree with Al Gore that it is important to stay positive in the work against global warming, focusing on what we can do, rather than the enormity of the task ahead. In that light I apologize for putting this out without a laundry list of "things you can do at home" to make it all better, but, inasmuch as DKos is a clearing house of sorts for information, I thought to put this out there.
Some days it's easier to be optimistic about our prospects than it is on others. I wish I had Al's strength. I also wish I had him for a president, but that's another diary altogether.
UPDATE. Just an afterthought, but I think what this points to is the necessity of alleviating the crisis now, because we have to have room to accomodate wild cards like this. The unkown unknowns. If you'll pardon my stating the obvious, climate is a complex system, and we cannot predict all the interactions between the atmosphere, the biosphere, and the geosphere. We need a buffer.
UPDATE II. Ok. It seems almost trivial, but this is my first time on the rec list! Wow. Please accept my well deseerved humility, and thanks.
UPDATE III. Please see this comment from billaurelMD about the atmospheric life of methane.
UPDATE IV.
Methane has a relatively short lifetime in the atmosphere [before converting to other forms of carbon!]. However, the concentration of methane actually affects its own atmospheric lifetime. The primary mechanism for its destruction is by reaction with hydroxyl radicals (OH-), the greater the concentration of methane the more the reductive power of the atmosphere (the supply of hydroxyl radicals) is reduced. If this feedback is included, then the true atmospheric lifetime of methane extends to about 12 years.
Methane has a global warming potential (GWP) of 23. This means that every kilogram of methane emitted to the atmosphere has the equivalent forcing effect on the Earth's climate of 23kg of carbon dioxide over a 100 year period.
Source.
UPDATE V. Wow. What a wealth of information out there! Hat tip to kafkananda for a great article on the environmental role of methan in general and methane hydrates in specific. Crikeys. When I woke up this morning I'd never freaking heard of methan hydrate, but now... This is just a great, great community! Man, what a learning curve. And it's not even lunchtime, yet.
UPDATE VI. I've just reread the article linked to above. Somebody should diary THAT. Really. 70 billion tonnes of methane just in Western Siberia. The article goes on to explain in more detail than I've done, here, how that factors into warming processes. Recommended read. Thanks again, kafkananda.
UPDATE VII. I have to go be a 3D person for a few hours. I'll be back in the early evening EDT. In the meantime, I need to direct you to some excellent comments that should not be missed in the flurry. Mary lnks to a Siberian version of the boiling lake, kafkananda should get far more mojo for his contribution, ybruit has summarised the link he provided as it pertains to methane hydrate, and skids has diaried methane hydrate before. I'm in a rush or i'd link you directly to those, but do stop by and give them a read. Oh heck. The comments are as good or better than the diary! Terryhallinen, captainlaser, and billlaurelMD, too.
Later.