Saturday, 18 February 2012

AIRS Videos Updates.

I have updated the January and December AIRS videos. From now on the series will be updated regularly, I'll aim to do it each month around the time of release of the latest image, which should be sometime in the second week of the month.

Tuesday, 14 February 2012

Arctic Methane: A Cause for Concern.

In the previous two posts I've outlined why I don't see observed methane release from the East Siberian Shelf (ESAS) to be the start of a fast process of catastrophic release. This is not to say I don't think this is a danger, however I see the danger as being more nuanced than some commentators and bloggers are claiming. Methane emissions from the Arctic region and ESAS may have the power to take our initial perturbation of CO2 emissions (being the largest single anthropogenic forcing, and the anthropogenic forcing with the greatest potential for future increase), amplify that perturbation, and perhaps even take AGW substantially out of our control. While we may not have enough fossil fuel to take us into the high-end IPCC scenarios, methane from the Arctic and the ESAS may just be able to take up the slack as our emissions fall this century due to geological constraints on fossil fuel production.

Monday, 6 February 2012

Arctic Methane: The paleo-perspective.

I've previously gone over some problems I have with the idea that we're on the verge of catastrophic climate change as a result of methane emissions in the Arctic, specifically from the East Siberian Shelf. A further problem I have with the idea of an imminent catastrophic release of CH4 from marine hydrates (or indeed from the Arctic tundra) is the lack of such events during recent paleo-climatic history. The Paleocene-Eocene Thermal Maximum (PETM) is generally cited as the best example of what may happen with regards Arctic methane hydrates and global warming. The parallels are strong, current emissions are occurring at a faster rate than during the PETM (Skeptical Science), and we know that there is a substantial issue regarding methane hydrates in the Arctic Ocean, the East Siberian Arctic Shelf being the largest concentrated store of these.

Thursday, 2 February 2012

Arctic Methane: Imminent, Abrupt and Massive Release?

In April 2008 Natalia Shakhova and colleagues (Shakhova et al 2008) presented data to the European Geosciences Union General Assembly in Vienna about the threat posed by methane clathrates in the East Siberian Arctic Shelf (ESAS). Their abstract read:
...we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. That may cause ~12-times increase of modern atmospheric methane burden with consequent catastrophic greenhouse warming.

When I first read that, the impact was the same as it would be for any reasonable person reading such a statement, coming as it did from people who are acknowledged experts in their field. It was only years later that I finally downloaded and read a copy of David Archer's "Methane hydrate stability and anthropogenic climate change." (Archer 2007) Having just finished reading a stack of papers on Arctic methane I'm still of the opinion that Archer's paper is required reading for anyone interested in this matter, and certainly should be read before people call 'apocalpyse' over Arctic methane. Archer 2007 is a summary paper that concludes that the release of methane is more likely to be a chronic release rather than a catastrophic one.