Impact of climate changes over the extratropical land on permafrost dynamics under RCP scenarios in the 21st century as simulated by the IAP RAS climate model

Abstract

Estimates of possible climate changes and cryolithozone dynamics in the 21st century over the Northern Hemisphere land are obtained using the IAP RAS global climate model under the RCP scenarios. Annual mean warming over the northern extratropical land during the 21st century amounts to 1.2-5.3°C depending on the scenario. The area of the snow cover in February amounting currently to 46 million km 2 decreases to 33-42 million km 2 in the late 21st century. According to model estimates, the near-surface permafrost in the late 21st century persists in northern regions of West Siberia, in Transbaikalia, and Tibet even under the most aggressive RCP 8.5 scenario; under more moderate scenarios (RCP 6.0, RCP 4.5, and RCP 2.6), it remains in East Siberia and in some high-latitude regions of North America. The total near-surface permafrost area in the Northern Hemisphere in the current century decreases by 5.3-12.8 million km 2 depending on the scenario. The soil subsidence due to permafrost thawing in Central Siberia, Cisbaikalia, and North America can reach 0.5-0.8 m by the late 21st century.

Permafrost degradation in the Western Russian Arctic

“…The Russian European Arctic and Northwestern Siberia (collectively referred to as the western Russian Arctic) are experiencing some of the highest rates of permafrost degradation (Romanovsky et al 2018, Biskaborn et al 2019. Regional climate warming in this region is projected to be almost twice the global average, which will result in increased permafrost degradation in Northern Eurasia through the end of the century (Arzhanov et al 2013, Anisimov et al 2013, Romanovsky et al 2017. Previous studies of permafrost in the Russian Arctic have already documented permafrost degradation manifested by warming temperatures, increasing annual active layer thickness, and northward retreat of permafrost extent (Oberman 2008, Vasiliev et While climatic factors play major roles in explaining permafrost and active layer trends across large regions, local vegetation and soil variability can also significantly offset these trends (Streletskiy et al 2014).…”

Spatiotemporal Changes in Active Layer Thickness under Contemporary and Projected Climate in the Northern Hemisphere

“…Previous studies have developed several ground-based measurement methods to determine ALT at the point scale by using mechanical probing, thaw tubes, and ground temperature measured in boreholes (Romanovsky and Osterkamp 1995;Zhang et al 1997Zhang et al , 2005Brown et al 2000;Hinkel et al 2003;Smith et al 2010;Zhao et al 2010). At the regional scale, some indirect measurements of ALT have been developed using, for example, remote sensing and modeling techniques (Goodrich 1978;Nelson and Outcalt 1987;Anisimov et al 1997Anisimov et al , 2002Anisimov et al , 2007Shiklomanov and Nelson 2002;Oelke et al 2004Oelke et al , 2007Liu et al 2012;Arzhanov et al 2013;Koven et al 2013).…”