Example 2: Methane - Potential Positive Feedback

Due to an increase in the temperature level of the atmosphere, fossilized methane is increasingly emitted. In this context, a dangerous positive feedback effect may be feared, which could soon exceed the limit value for the possibility of human intervention.

Climate change in the subarctic regions leads to an above average increase in temperature. The permafrost soil in those regions melts and emits stored fossilized methane. Anaerobic processes begin and also produce methane.

The methane emissions from the permafrost soil (460 ppm of potential carbon dioxide equivalence) clearly exceed the anthropogenic emissions goal. In combination, a value of around 800 ppm would result. The average global temperature would thus rise by far more than 2°C (previous desired value).

By reason of the associated grave climatic changes, the temperature at the sea floor^[46] could increase in the area of the continental shelves.

The geothermal heat would release powerful fixed methane hydrate deposits from the floor in water and gaseous methane^[47].

The gaseous methane would diffuse through the methane hydrate and emerge into the atmosphere. In addition, the danger of explosive methane emissions (so-called blowouts)^[48] would exist, due to the sudden failure of methane hydrate layers. Landslides and the resulting tsunami waves would have to be reckoned with.

The release of methane from fossilized methane hydrate deposits would lead to a further increase in the average global atmospheric temperature.