How will permafrost affect and be affected by global environmental change?
Posted on August 27th, 2009 Submitted by hlantuit Categorized as Biodiversity, Earth System, Interdisciplinary, Other Tagged as alpine environments, Arctic sea ice, CO2, greenhouse gas, methane, permafrost 41 Permafrost is defined as ground that remains at or below 0°C for at least two consecutive years. Permafrost underlies approximately 25 % of the land area in the northern hemisphere and can be up to 1500 m thick. Under current climate-change scenarios, permafrost degrades from both the top and bottom, increasing the depth of the “active layer”, and the extent of talik formation. The deepening of the active layer could trigger the massive decomposition of organic matter stored in the first three meters below surface. The most recent estimates put the organic carbon pool in permafrost at 50% of the global soil organic carbon pool. This pool is equivalent to twice the amount of carbon in the atmosphere. The decomposition processes would lead to the emission of vast quantities of green
