There seems to be some attempt to portray this finding as being a cause for alarm — e.g. here. All that it in fact shows, however, is that previous estimates were wrong — an all too common event among Warmists. It does NOT show that methane release has accelerated in recent years

Vast quantities of methane are stored in ocean sediments, mostly in the form of clathrates, but methane is also trapped in submerged terrestrial permafrost that was flooded during the last deglaciation. There is thus concern that climate warming could warm ocean waters enough to release methane cryogenically trapped beneath the seabed, causing even more warming. Shakhova et al. report that more than 80% of the bottom water, and more than 50% of the surface water, over the East Siberian Arctic Shelf, is indeed supersaturated with methane that is being released from the sub-sea permafrost, and that the flux to the atmosphere now is as great as previous estimates of that from the entire world ocean.


Journal abstract below:

Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf

By Natalia Shakhova et al.

Remobilization to the atmosphere of only a small fraction of the methane held in East Siberian Arctic Shelf (ESAS) sediments could trigger abrupt climate warming, yet it is believed that sub-sea permafrost acts as a lid to keep this shallow methane reservoir in place. Here, we show that more than 5000 at-sea observations of dissolved methane demonstrates that greater than 80% of ESAS bottom waters and greater than 50% of surface waters are supersaturated with methane regarding to the atmosphere. The current atmospheric venting flux, which is composed of a diffusive component and a gradual ebullition component, is on par with previous estimates of methane venting from the entire World Ocean. Leakage of methane through shallow ESAS waters needs to be considered in interactions between the biogeosphere and a warming Arctic climate.

Science 5 March 2010: Vol. 327. no. 5970, pp. 1246 – 1250

Posted by John Ray (M.A.; Ph.D.). For a daily critique of Leftist activities, see DISSECTING LEFTISM. To keep up with attacks on free speech see TONGUE-TIED. Also, don’t forget your daily roundup of pro-environment but anti-Greenie news and commentary at GREENIE WATCH . Email me here

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