CM – Thawing permafrost releases greenhouse gases from deep below

0

Click here to log in with

or

Forgot Password?

Learn more

August 2, 2021

from the University of Bonn

What impact did the 2020 summer heat wave have in Siberia? In a study conducted by the University of Bonn, geologists compared the spatial and temporal distribution of methane concentrations in the air in Northern Siberia with geological maps. The result: The methane concentrations in the air after last year’s heat wave indicate that increased gas emissions originate from limestone formations. The study is published in the journal Proceedings of the National Academy of Sciences (PNAS).

googletag.cmd.push (function () {googletag.display (‘div-gpt-ad-1449240174198-2’);});

Permafrost soils cover large areas of the northern hemisphere, particularly in northern Asia and North America. If they thaw in a warming world, this can be dangerous, since when thawing CO2 and methane are released – and amplify the anthropogenic greenhouse gas effect. « Methane is particularly dangerous here because its warming potential is many times higher than that of CO2, » explains Prof. Dr. Nikolaus Froitzheim from the Institute for Geosciences at the University of Bonn. Pessimists were therefore already speaking of an imminent « methane bomb ». Most previous projections, however, have shown that greenhouse gases from thawing permafrost will « only » contribute about 0.2 degrees Celsius to global warming by 2100. This assumption is now being called into question by a new study by Nikolaus Froitzheim and his colleague Jaroslaw Majka (Cracow / Uppsala). and Dmitry Zastrozhnov (St. Petersburg).

Most previous studies only dealt with emissions from the decay of plant and animal remains in the permafrost soil itself. In their current study, researchers working with Nikolaus Froitzheim have found the methane concentrations in of the Siberian air compared to geological maps. They found significantly increased concentrations in two areas of northern Siberia – the Taymyr fold belt and the edge of the Siberian platform. What is striking about these two elongated areas is that the bedrock there is formed by limestone formations from the Paleozoic Era (the period from about 541 million years ago to about 251.9 million years ago).

In both areas, the increased concentrations occurred during the extreme heat wave in summer 2020 and lasted for months afterwards. But how did the additional methane come about? « The soil formations in the observed areas are very thin or even non-existent, so that methane emissions from the decay of organic soil matter are unlikely, » says Niko Froitzheim. He and his colleagues therefore suspect that fracture and cave systems in the limestone, which was clogged by a mixture of ice and gas hydrate, became permeable when heated. “This allows natural gas, which is mainly methane, to reach the earth’s surface from deposits inside and below the permafrost,” he says.

The scientists now want to investigate this hypothesis using measurements and model calculations in order to find out how much and how quickly natural gas can be released. “The estimated amounts of natural gas underground in Northern Siberia are enormous. If parts of it get into the atmosphere when the permafrost thaws, this could have dramatic effects on the already overheated world climate, ”says Niko Froitzheim.

Use this form if you have identified a typographical error, inaccuracy, or if you would like to submit a change request to the contents of this page.
For general inquiries, please use our contact form.
For general feedback, use the public comments section below (please follow the guidelines).

Your feedback is important to us. Due to the high volume of messages, however, we cannot guarantee individual responses.

Your email address will only be used to let the recipient know who sent the email. Neither your address nor that of the recipient will be used for any other purpose.
The information you entered will appear in your email message and will not be stored in any form by Phys.org.

Receive weekly and / or daily updates in your inbox.
You can unsubscribe at any time and we will never pass your data on to third parties.

This website uses cookies to make navigation easier, to analyze your use of our services and to provide third-party content.
By using our website, you confirm that you have read and understood our privacy policy
and terms of use.

Keywords:

Climate change,Permafrost,Greenhouse gas,Thaw,Siberia,Arctic methane emissions,Climate change, Permafrost, Greenhouse gas, Thaw, Siberia, Arctic methane emissions,,Climate change,Greenhouse gas emissions,Arctic,Russia,Environment,World news,,,

Donnez votre avis et abonnez-vous pour plus d’infos

[gs-fb-comments]

Vidéo du jour: