Around 3350 gigatonnes of carbon are stored in the world's soils - about 3.8 times as much as in the atmosphere and 6.4 times as much as in global vegetation. Recent studies suggest that half of all global soil carbon is stored in the permafrost region. The organic material known as "permafrost carbon" is currently protected by cold climate conditions, but the latter also ensure that it is highly vulnerable to future climate warming.
In the factsheet "Permafrost", the team led by first author Dr Jens Strauss from AWI-Potsdam summarises the state of research on the global importance of permafrost carbon stocks. Permafrost is ground that is frozen all year round and is composed of soil, rock and ice, among other things. Large amounts of organic carbon have accumulated over several millennia, as the cold and wet conditions typical of many permafrost regions limit decomposition processes.
The research team describes the distribution of permafrost regions, the potential for permafrost soils to absorb or release carbon from the atmosphere due to changes in climate and conditions of use. An important role is played by the self-reinforcing effect through the release of the greenhouse gases carbon dioxide and methane. In addition to rising temperatures, the report also addresses the risks posed by increasing forest fires, changing hydrological conditions or the stability of permafrost, as well as the impacts on humans.
The report "Recarbonizing global soils: a technical manual of recommended management practices" is available for download here, the permafrost factsheet is part of Volume 2: Hot Spots and Bright Spots of Soil Organic Carbon.