Comment: Wouldn't dismiss the significance

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In post: B00M!

Wouldn't dismiss the significance

of methane - it doesn't stay in the atmosphere as long as CO2,
but it's much more potent (as in 20-30 times stronger effect) as
a greenhouse gas, and the concentration in the Northern Hemisphere
atmosphere is higher than it's been in at least 400,000 years.

The permafrost contains huge amounts of methane locked
in frozen water, but the permafrost is underlaid with unfrozen
water bearing layers called talik that are kept unfrozen by the heat
of the earth.

It's thought that when melting happens on the bottom of the frozen
layer you can end up with big methane bubbles trapped by an overlayer
of permafrost or in the case of clathrates on continental shelves, big
bubbles under layers of sediment.

In Siberia they have been seeing more and more cases of talik coming all
the way to the surface (as the permafrost layer melts) and detected methane
releases from these. But as you can see below, they have been warning of the
danger of sudden large scale releases since at least 2008 and that is *maybe*
what happened here. Guess you might want to be careful where you lit up a
camp stove up that way...

"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."

BTW - 1 Gt = one BILLION tons