Strong Methane Emissions On the Siberian Shelf

rrohbeck writes "The Independent reports brand-new results of high concentrations of methane — 100x normal — above the sea surface over the Siberian continental shelf. A large number of methane plumes have been discovered bubbling up from the sea floor. This is probably due to methane clathrate, buried under the sea floor before the last ice age, breaking up as higher water temperatures melt the permafrost that had contained it."

Comments

People have been expecting these Methane clouds

[G3ckoG33k]

People have been expecting these Methane clouds:
http://afp.google.com/article/ALeqM5j3U0vEk53bVXHIcGUqqO64rvDAUg

"Melting of methane ice unleashed runaway global warming some 635 million years ago, according to a study released Wednesday that has implications for today's climate-change crisis.

Release of the potent greenhouse-gas, at first in small amounts and then in massive volumes, brought a sudden end to the planet's longest Ice Age, its authors believe.

During the "Snowball Earth" era, Earth froze over completely, with glaciers that crept down into the tropics and possibly even reached the equator."

The Hives: Hate to Say I told You So:

http://www.youtube.com/watch?v=tsm2hSKkH7E

Mass extinction at end of Permian

[AliasMarlowe]

The mass extinction at the end of the Permian has been attributed to numerous causes. One of the prime theories also has to do with rapid release of methyl hydrates from ocean-floor clathrates.

The theory goes along the lines that oceanic overturning (exchange of bottom waters with surface waters) was limited in the Permian (even after the end of the Permo-Carboniferous glacial period), allowing accumulation of clathrates in oceanic sediments. However, overturning increased in the late Permian due to changes in oceanic circulation. This is conjectured to have caused massive releases of methane from methyl hydrates, with consequent large rapid swings in climate on land and in sea.

The evidence is not conclusive, but is strong. Most of it is derived from studies of marine fossils and isotope ratios. Discussion of the evidence and assessment of this and other theories for the extinction may be found, for example, in:
D.H. Erwin, The Great Paleozoic Crisis: Life and Death in the Permian, Columbia University Press, New York NY, 1993. ISBN:0715301306.

Of course, oceanic overturning is much stronger in the modern world, with deepwater formation especially strong in the North Atlantic and at the margins of Antarctica. This suggests the potential for clathrate release is probably rather less than it was in the late Permian, but not necessarily negligible. Another conjectured effect of global warming is slowing of oceanic overturning

The degree to which evidence supports these conjectures regarding ancient disruptions to climate is open to interpretation.

Re:yes and no

[jipn4]

Where do you people come up with this sort of nonsense?

Here's the projected relationship between CO2 concentrations and temperature increase:

http://en.wikipedia.org/wiki/Image:IPCC_AR4_WGIII_GHG_concentration_stabilization_levels.png

Notice how it keeps going up?

That's assuming we don't hit some kind of positive feedback loop.