"Methane -- a greenhouse gas 23 times more powerful than carbon dioxide -- is being released from the permafrost at a rate five times faster than thought, according to a study being published (Sept.7) in the journal Nature. The findings are based on new, more accurate measuring techniques."
"The higher the temperature gets, the more permafrost we melt, the more tendency it is to become a more vicious cycle," said Chris Field, director of global ecology at the Carnegie Institution of Washington, who was not part of the study. "That's the thing that is scary about this whole thing. There are lots of mechanisms that tend to be self-perpetuating and relatively few that tend to shut it off."
"Most of the methane-releasing permafrost is in Siberia. Another study earlier this summer in the journal Science found that the amount of carbon trapped in this type of permafrost -- called yedoma -- is much more prevalent than originally thought and may be 100 times the amount of carbon released into the air each year by the burning of fossil fuels."
"Most of the yedoma is in little-studied areas of northern and eastern Siberia. What makes that permafrost special is that much of it lies under lakes; the carbon below gets released as methane. Carbon beneath dry permafrost is released as carbon dioxide."
"Scientists aren't quite sure whether methane or carbon dioxide is worse. Methane is far more powerful in trapping heat, but only lasts about a decade before it dissipates into carbon dioxide and other chemicals. Carbon dioxide traps heat for about a century."
"It's kind of like a slow-motion time bomb," said Ted Schuur, a professor of ecosystem ecology at the University of Florida and co-author of the Science study. "There's these big surprises out there that we don't even know about."
Thanks to Joan Saxe via Sierra Cub Energy Forum