Melting Permafrost

From the NOAA Arctic Program

• Northern permafrost region soils contain 1,460-1,600 billion metric tons of organic carbon, about twice as much as currently contained in the atmosphere.
• This pool of organic carbon is climate-sensitive. Warming conditions promote microbial conversion of permafrost carbon into the greenhouse gases carbon dioxide and methane that are released to the atmosphere in an accelerating feedback to climate warming.
• New regional and winter season measurements of ecosystem carbon dioxide flux independently indicate that permafrost region ecosystems are releasing net carbon (potentially 0.3 to 0.6 Pg C per year) to the atmosphere. These observations signify that the feedback to accelerating climate change may already be underway.

See:

"Permafrost and the Global Carbon Cycle" - NOAA - T Schuur, Northern Arizona University