PhillipS

That is an interesting article, but please understand that it was not, and will not, be peer-reviewed. It was published in EOS, the weekly AGU newpaper and not in one of the AGU research journals. As expressed on the AGU.org website: Eos is a newspaper, not a research journal. Furthermore: Eos does not consider or accept manuscripts that have previously been published or that are being considered by other publications. Which is not to say that it is automatically flawed, just that it is one journalist's opinion and not research. One thing that struck me when I read the abstract was the author's simplistic model of the methane deposits being 200 meters below the seafloor. That is simply not true and is very easy to debunk. The depth of the hydrate deposits, and the thickness of the overlying sediments (including permafrost if persent), vary considerably - with the methane hydrate deposits actually being exposed to seawater in some places. Here's a pic fyi: The presentation TerryM linked to is a much better explanation of the situation off the coast of Siberia.

It appears that the datapoints plotted represent weekly methane readings. For most of 2011 the values were relatively stable around 1900 ppb. The last two readings, 2175 and 2200 ppb, are roughly 15% higher. Which would certainly be alarming if they represent a massive methane release. But, as others have pointed out, there's just not enough data. If you look at the longer term record you'll see a number of outliers among the datapoints. I have no idea what causes the abnormal readings but given that they are taken at Barrow, AK, I'm pretty sure that they're not cow farts as LEK suggested. Reindeer farts, maybe. My suggestion is to continue to monitor the news and journals for fresh info as it becomes available. And to continue to expose misinformation and sloppy thinking whenever you find it.

Does anyone know whether the GHG effect of methane is linear (double the gas concentration has double the effect), or logarithmic like CO2 (each doubling of the gas concentration has the same increase in effect)?

Methane releases can happen, and have happened, for natural reasons - but that doesn't eliminate the possibility of humans triggering a massive methane release in the near term. Clathrates, frozen methane hydrates, can be found in many places around the world, for example in the Gulf of Mexico, and can be stable for eons so long as the temperature and pressure are correct. The massive methane deposits along the arctic coasts of Siberia, Alaska, and Canada are in relatively shallow waters so it is primarily temperature that keeps them stable. AGW is increasing the Ocean Heat Content (OHC) for the arctic, so some clathrate deposits are approaching instability. A recent paper on the topic: Simulation of Arctic Gas Hydrate Dissociation in Response to Climate Change: Basin-Scale Assessment And an excerpt from the abstract: Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. Field investigations have discovered substantial methane gas plumes exiting the seafloor along the Arctic Ocean margin, and the plumes appear at depths corresponding to the upper limit of a receding gas hydrate stability zone. It has been suggested that these plumes may be the first visible signs of the dissociation of shallow hydrate deposits due to ongoing climate change in the arctic. Unfortunately, the full paper is behind a paywall, but a search with Google Scholar turns up a number of relevant papers. WinterWxLuvr, adaptation isn't a quick, or inexpensive, process - and history is full of examples of civilizations collapsing from their failure to adapt to changes. The longer we continue BAU, the more GHGs we dump into the atmosphere, the less time and resources wil be available for the inevitable attempt to adapt. The era of cheap energy is unsustainable because fossil fuels are finite. So the question becomes do we look ahead to the future and make the needed transition soon, or do we ignore reality, put off the inevitable shift from fossil fuels until a full-blown crisis develops, and hope that we've left enough resources for our descendants to hold civilization together? Are we smart enough to be conservatives in the original sense - conserving resources for future generations?

Having read the back and forth in this thread, I think it's time for all parties to switch to decaf. Vergent, thank you for posting the link to the article. It is interesting and alarming - but it's just a news article. It's not peer-reviewed science . . . heck, it's not even non-peer-reviewed science. It is a news article which was written to grab the readers' attention. And I confess it did so. I hope all parties can agree that before anybody can assess how significant and serious this methane release is we need real data. We don't know the extent of the venting, the amount of methane being released, or (worst case) whether this is an indication that the massive arctic methane deposits are becoming unstable. Hopefully the Russian researhers will publish their results soon. Until then it is largely pointless to speculate. Methane leaks are not new - you can search youtube and find lots of alarming videos. Here's the url to a video of in the summer of 2007. If the newly discovered vents are reaching the surface I expect they look like a larger version of these vents. And here's a video on 'The Door to Hell', a methane leak that's been burning for over thirty years.For those skeptical and denialist posters who keep singing "Don't worry, be happy!" - you might want to do some reading on Extinction Events and how methane releases have been implicated in several of them. Wikipedia has a good article on the Clathrate Gun Hypothesis which provides link for further reading. Here's an excerpt from that article: One exception, however, may be in clathrates associated with the Arctic ocean, where clathrates can exist in shallower water stabilized by lower temperatures rather than higher pressures; these may potentially be marginally stable much closer to the surface of the sea-bed, stabilized by a frozen 'lid' of permafrost preventing methane escape. Recent research carried out in 2008 in the Siberian Arctic has shown millions of tons of methane being released, apparently through perforations in the seabed permafrost,[11] with concentrations in some regions reaching up to 100 times normal.[12][13] The excess methane has been detected in localized hotspots in the outfall of the Lena River and the border between the Laptev Sea and the East Siberian Sea. Some melting may be the result of geological heating, but more thawing is believed to be due to the greatly increased volumes of meltwater being discharged from the Siberian rivers flowing north.[14] Current methane release has previously been estimated at 0.5 Mt per year.[15] Shakhova et al. (2008) estimate that not less than 1,400 Gt of carbon is presently locked up as methane and methane hydrates under the Arctic submarine permafrost, and 5–10% of that area is subject to puncturing by open taliks. They conclude that "release of up to 50 Gt of predicted amount of hydrate storage [is] highly possible for abrupt release at any time". That would increase the methane content of the planet's atmosphere by a factor of twelve,[16][17] equivalent in greenhouse effect to a doubling in the current level of CO2. Remember, these methane vents are in addition to the warming caused by our fossil fuel use so if the article is true we could see a much larger rise in global temperatures over the next few decades. So, for now, let's see what the researchers can tell us. I think we'll still have time for panic if it's warranted.