This past month a large crater was discovered in Yalmal Peninsula in Siberia.  Scientist have been there to study it.  They didn't come to any conclusions other then it was formed the same way a cork pops from a bottle. This is an area of tundra that is rich in methane gas.  It is believed that the thawing of the permafrost cause the gas to escape blowing a hole.  They have now found 2 other holes that are smaller.  Methane is a more serious threat to global warming then CO2.  This gives the scientist more sites to study and may lead to an explanation. The article includes interesting pictures. 

(One more time ...)

Okay, I added the last part. But you have to wonder if they've considered the outcome if their wish is granted. I'm quite fond of Joe, just didn't realize so many Republicans are, too.