Eurasian permafrost instability constrained by reduced sea-ice cover

• Published in: Quaternary science reviews 2012-02, Vol.34, p.16-23
• Main Authors: Vandenberghe, J., Renssen, H., Roche, D.M., Goosse, H., Velichko, A.A., Gorbunov, A., Levavasseur, G.
• Format: Article
• Language: English
• Subjects: Arctic sea-ice; Continental interfaces, environment; LGM permafrost extent; Marine; Ocean, Atmosphere; Permafrost distribution; Permafrost instability; Permafrost modelling; Sciences of the Universe
• ISSN: 0277-3791; 1873-457X
• DOI: 10.1016/j.quascirev.2011.12.001

In order to specify potentially causal relationships between climate, permafrost extent and sea-ice cover we apply a twofold research strategy: (1) we cover a large range of climate conditions varying from full glacial to the relatively warm climate projected for the end of the 21st Century, (2) we combine new proxy-based reconstructions of Eurasian permafrost extent during the LGM and climate model simulations. We find that that there is a linear relationship between the winter sea-ice extent in the North Atlantic and Arctic Oceans and the latitude of the southernmost permafrost limit in Eurasia. During the LGM, extensive sea-ice cover caused a zonal permafrost distribution with the southern margin extending W–E and reaching 47°N, contrasting with the present-day NW–SE trending margin (66°–52°N). We infer that under global warming scenarios projected by climate models for the 21st Century the Arctic sea-ice cover decline will cause widespread instability of, mainly discontinuous, permafrost in Eurasian lowlands. ► Southern limit of (dis)continuous permafrost in Eurasia during LGM is reconstructed. ► Permafrost extent in Eurasia is causally related to Arctic winter sea-ice extent. ► Predicted Arctic sea-ice decline will cause widespread instable Eurasian permafrost.