Permafrost thawing faster than expected due to extreme summer rainfall

The average rate of global warming has been three times faster than the rate of warming in the northern part of the planet. The permanently frozen soil of the northern part of the planet thaws. This process is being accelerated by extreme summer rain. The thaw of the permafrost may be even faster because of a warmer climate.

The settlements of humans who live on it form the foundation of thearctic. The soil loses its load-bearing capacity when the permafrost thaws. The organic carbon stored in the frozen soil can be used to make greenhouse gases, such as CO 2 and methane, which contribute to global warming. The positive feedback loop is caused by the release of greenhouse gases through the thaw.

The precipitation in the region is increasing. This has a negative impact on the permafrost during the winter. A thicker layer of snow protects the permafrost from the cold air, so it doesn't cool as much. The effect of precipitation in the summer was unknown.

A rain experiment.

The Nature Management chair group at Wageningen University carried out an irrigation experiment on the Northeast Siberia tundra to study the effects of extreme summer precipitation. Half of the monitoring sites used sprinklers to give them more water. The experiment showed the effects of a very wet summer. The sites were monitored for several years for permafrost thaw depth.

The soil is more susceptible to the decomposition of soil carbon into greenhouse gas when the permafrost thaws more quickly in the irrigated sites. An important finding was that the effect of an extremely wet summer lasted for several years, even after the sprinkler test. We were not surprised that the permafrost would thaw to a greater depth during wet summers, but that the effect would be so extreme and last for a long time.

There is a risk ofunderestimating climate change.

If we only take warmer temperatures into account, we will underestimate how much permafrost is thawing as a result of climate change. This could lead us to underestimate future greenhouse gas emissions caused by permafrost thaw, and therefore our emissions targets to stay within the one-and-a-half or two degrees of global warming may turn out to be too optimistic.

Future research will hopefully reveal the extent to which the sensitivity of permafrost to rain varies in different parts of the world, so that more reliable estimates of future thaw can be made.

More information: Rúna Í. Magnússon et al, Extremely wet summer events enhance permafrost thaw for multiple years in Siberian tundra, Nature Communications (2022). DOI: 10.1038/s41467-022-29248-x Journal information: Nature Communications Citation: Permafrost thawing faster than expected due to extreme summer rainfall (2022, March 23) retrieved 23 March 2022 from https://phys.org/news/2022-03-permafrost-faster-due-extreme-summer.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.