Background for the CENPERM research program (1)
Soil ecosystems with underlying permafrost cover nearly 25% of the ice-free land area in the northern hemisphere and store almost half of the global soil carbon. Future climate changes are predicted to have the most pronounced effect in northern latitudes. These Arctic ecosystems are therefore subject to dramatic changes following thawing of permafrost, glacial retreat, and coastal erosion.
The most dramatic effect of permafrost thawing is the accelerated decomposition and potential mobilization of organic matter stored in the permafrost. This will impact global climate through the mobilization of carbon and nitrogen accompanied by release of greenhouses gases as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).
The need for a long term perspective
The net effects of these changes are controlled by coupled feedback mechanisms. The impact will differ with respect to local climate, amount of carbon and nitrogen stored in the soil, ice content, temperature and the dynamics of the active soil layer above the permafrost.
As awareness and concern of recent rapid climatic changes in the Arctic grows, so does the need for a long-term perspective on these changes. Improved knowledge on the nature of the coupled biological and climatic feedback mechanisms following accelerated permafrost thawing will be essential. Permafrost is currently not well represented in global models and will not be included in the fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), due for release in stages between September 2013 and October 2014. This lack of representation of permafrost-influenced climate feedback is a recognized source of uncertainty.