Der SPiegel (Germany) reports:

Researchers have found ...evidence that the frozen Arctic floor has started to thaw and release long-stored methane gas. The results could be a catastrophic warming of the earth, since methane is a far more potent greenhouse gas than carbon dioxide. But can the methane also be used as fuel?

(aerial photo: The Lena River flowing through Russian Siberia and empties into the Arctic Ocean. This satellite image shows the river delta, where methane concentrations are unexpectedly high).

It's always been a what-if scenario for climate researchers: Gas hydrates stored in the Arctic ocean floor -- hard clumps of ice and methane, conserved by freezing temperatures and high pressure -- could grow unstable and release massive amounts of methane into the atmosphere. Since methane is a potent greenhouse gas, more than carbon dioxide, the result would be a drastic acceleration of global warming. Until now this idea was mostly academic; scientists had warned that such a thing could happen. Now it seems more likely that it will.

...