Organic carbon has often been bound for several thousand years not only in peatlands, but also in permanently frozen soil (permafrost). Peatlands and permafrost are important natural carbon stores. However, to carry out this storage function peatlands require a high water level all year round, whereas permafrost depends on low temperatures to avoid thawing. If, however, the groundwater level falls and oxygen reaches the carbon stored in the peat, carbon dioxide (CO2) in particular escapes due to the degradation of organic material. In contrast, the release of methane (CH4) is predominant if permafrost thaws. Rising tem¬peratures, long droughts and also the draining of peatlands result in the degradation the carbon stored in the soil and a release in the atmosphere as a greenhouse gas.
According to a report by the IPCC (Intergovernmental Panel on Climate Change) published in spring 2014, in particular the continually rising concentration of CO2 and also CH4 in the atmosphere is held responsible for the worldwide temperature increase and therefore climate change. Both gases are therefore also called greenhouse gases, as they absorb part of the thermal radiation emitted from the soil which otherwise could escape into the universe. If this natural effect did not exist, the average worldwide temperature would only be -18 °C. The increase in CO2 and CH4 causes a continuous increase in the Earth’s average temperature.
However, many scientists are of the opinion that the impact of human beings caused by the increased emission of CO2 serves to considerably enhance the natural greenhouse effect.
The consequences which can occur if this natural equilibrium is disturbed are being investigated by scientists of the German Research Centre for Geosciences - GFZ in the Helmholtz junior research group TEAM (Trace Gas Exchange in the Earth-Atmosphere System on Multiple Scales). This team is concerned with the interactions between the Earth’s surface and the atmosphere, in particular the exchange of CO2 and CH4, on different spatial scales. "Our junior research group TEAM has two projects this year. With both of these we wish to obtain new knowledge about how much of the greenhouse gases methane and carbon dioxide in the underground is released into the atmosphere and which processes are involved”, says Daniela Franz from the GFZ.
