Blogs, or to spell out the contraction, web logs, were originally just that: a log of interesting things found on the internet. Yesterday was a day when I rediscovered that tradition. Prompted by a comment from glaciologist Mauri Pelto on my recent Greenland post, I started off by making a visit to NASA’s MODIS Rapid Response System image site, which provides access to near real-time imagery from the Aqua and Terra satellites (click on Near-real-time production under “quick links” to be taken to the most recent images). The images aren’t fully processed (you can see “stripes” and slight distortions), but they give you a good look at what’s going on. I first went and had a look at what spring on the Petermann glacier in NW Greenland looked like:
Tag: Arctic
Siberian seabed methane: first numbers
The latest estimate of methane release from the shallow seas off the north coast of Russia — the East Siberian Arctic Shelf (ESAS) — suggests that around 8 teragrams per year (1Tg = 1 million tonnes) of the gas are reaching the atmosphere. This is equivalent to previous estimates of total methane release from all oceans. The study, led by Natalia Shakhova and Igor Semiletov and published in this week’s Science (Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf, Science 5 March 2010, Vol. 327. no. 5970, pp. 1246 – 1250 DOI: 10.1126/science.1182221), is based on fieldwork over 2003 – 2008. Over 80% of the bottom water over the ESAS was found to be supersaturated with dissolved methane, and 50% of the surface water. More than 100 “hotspots’ were discovered, where large quantities of methane are escaping from the sea-floor. Here’s Shakhova discussing the paper’s findings in a University of Alaska Fairbanks video (press release):
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Methane rise continues
More cautionary news on rising methane levels is reported in yesterday’s Independent. Two leading experts on CH4in the atmosphere, Euan Nisbet and Ed Dlugokencky, were due to reveal at a conference that, after a decade of near-zero growth, “globally averaged atmospheric methane increased by [approximately] 7ppb (parts per billion) per year during 2007 and 2008.” They consider it likely that 2009 will have shown the same rising trend, since the figures for the first half of the year showed a 7 ppb rise on the 2008 level.
They are properly cautious about the rises and comment that they may just be a couple of years of high growth which may drop back to what it was. But they stress the importance of understanding the causes of the rises, because of the potential for increased CH4 emissions from strong positive climate feedbacks in the Arctic where there are unstable stores of carbon in permafrost. Permafrost melt carries the potential for methane release.
If there is a feedback mechanism at work it’s bad news as the Independent makes clear in terms that its readers can understand:
“Many climate scientists think that frozen Arctic tundra… is a ticking time bomb in terms of global warming, because it holds vast amounts of methane, an immensely potent greenhouse gas. Over thousands of years the methane has accumulated under the ground at northern latitudes all around the world, and has effectively been taken out of circulation by the permafrost acting as an impermeable lid. But as the permafrost begins to melt in rising temperatures, the lid may open – with potentially catastrophic results”.
This is not alarmism on the part of the Independent. The scientists involved in reporting the rises are careful and restrained in their statements. We may hope that the increases turn out not to be significant in terms of feedbacks under way. But it is a sober reminder of how quickly things may change if natural feedbacks kick in and amplify the warming already caused by our human activity. See Gareth’s earlier post on methane hydrates in the Arctic.
Incidentally, it was good to see a newspaper competently and thoroughly reporting climate change science news. It can happen, and when it does it’s a different world from the ignorant and careless journalism that has been so apparent recently in relation to the UEA emails and the IPCC report. Rationality and proportion marked an excellent piece of science reporting.
Oops, he did it again
It pays to beware of leaving hostages to fortune: saying or doing something that might cause you some embarrassment in the future. There’s a very fine example in this recent blog post by Ian Wishart, titled “Top 10 global warming myths exposed“. It takes the form of a piece Wishart has submitted to the Coromandel Chronicle, taking exception to a column by Thomas Everth [PDF]. He begins:
In a blatant effort to mislead and scare your readers, Green blogger Thomas Everth makes more errors in the first 200 words of his recent global warming diatribe than I have made in my last three books totalling around 400,000 words.
As hostages go, that’s pretty impressive. Wishart proceeds to find fault with ten of Everth’s opening points, but does he make a few mistakes of his own in the process? I’m going to take a long, hard look: is that hostage feeling lucky?
Siberian Shelf methane increased in 2009
Methane release from the permafrost and hydrates under the East Siberian Shelf in autumn 2009 was the highest ever recorded, the leader of the International Siberian Shelf Study (ISSS), Igor Semiletov, has told the BBC. The results of last autumn’s research cruises are being prepared for publication in the near future. The BBC also quotes Semiletov’s colleague Prof Orjan Gustafsson from Stockholm University:
He said that methane measured in the atmosphere around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.
Gustaffson went on to say that “so far” there was no cause for alarm, and stressed the need for further study. Sounds like a scientist… For background, check out last year’s WWF Arctic report (I discussed the chapter on Arctic methane here), and my posts on the 2008 ISSS expeditions (one, two). Looks like the methane release is confirmed as chronic, but not yet (if we’re lucky) acute.