Greenhouse emissions from Siberian rivers peak as permafrost thaws
Permafrost soils store large quantities of frozen carbon and play an important role in regulating Earth's climate. In a study published in Nature Geoscience, an international team of researchers, including SLU, now show that river greenhouse gas emissions rise high in areas where Siberian permafrost is actively thawing.
As permafrost degrades, previously frozen carbon can end up in streams and rivers where it will be processed and emitted as greenhouse gases from the water surface directly into the atmosphere. Quantifying these river greenhouse gas emissions is particularly important in Western Siberia – an area that stores vast amounts of permafrost carbon and is a home to the Arctic's largest watershed, Ob' River.
Now researchers, one of them SLUs Hjalmar Laudon, have shown that river greenhouse gas emissions peak in the areas where Western Siberian permafrost has been actively degrading and decrease in areas where climate is colder, and permafrost has not started to thaw yet. The research team has also found out that greenhouse gas emissions from rivers exceed the amount of carbon that rivers transport to the Arctic Ocean.
Quantifying river greenhouse gas emissions from permafrost-affected areas in general and in Western Siberia in particular is important as it improves our understanding the role such areas play in the global carbon cycle as well as increases our abilities of predicting the impacts of a changing climate on the Arctic.
The large-scale changes that take place in the Arctic due to warming exert a strong influence on the climate system and have far-reaching consequences for the rest of the world.
S. Serikova, O.S. Pokrovsky, P. Ala-Aho, V. Kazantsev, S.N. Kirpotin, S.G. Kopysov, I.V. Krickov, H. Laudon, R.M.Manasypov, L.S. Shirokova, C. Soulsby, D. Tetzlaff and J. Karlsson, High riverine CO2 emissions at the permafrost boundary of Western Siberia, Nature Geoscience, DOI[СС1] 10.1038/s41561-018-0218-1.