Alpine permafrost could account for a quarter of thawed carbon based on Plio-Pleistocene paleoclimate analogue

• Main Authors: Cheng, Feng, Garzione, Carmala, Li, Xiangzhong, Salzmann, Ulrich, Schwarz, Florian, Haywood, Alan M, Tindall, Julia, Nie, Junsheng, Li, Lin, Wang, Lin, Abbott, Benjamin W, Elliott, Ben, Liu, Weiguo, Upadhyay, Deepshikha, Arnold, Alexandrea, Tripati, Aradhna
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2022
• Subjects: Physical Geography and Environmental Geoscience; Biological Sciences; Ecology; Earth Sciences; Geology; Climate Action; Carbon; Climate; European Alpine Region; Permafrost; Temperature; permafrost
• Online Access: https://escholarship.org/uc/item/4qk472fk

Estimates of the permafrost-climate feedback vary in magnitude and sign, partly because permafrost carbon stability in warmer-than-present conditions is not well constrained. Here we use a Plio-Pleistocene lacustrine reconstruction of mean annual air temperature (MAAT) from the Tibetan Plateau, the largest alpine permafrost region on the Earth, to constrain past and future changes in permafrost carbon storage. Clumped isotope-temperatures (Δ47-T) indicate warmer MAAT (~1.2 °C) prior to 2.7 Ma, and support a permafrost-free environment on the northern Tibetan Plateau in a warmer-than-present climate. Δ47-T indicate ~8.1 °C cooling from 2.7 Ma, coincident with Northern Hemisphere glacial intensification. Combined with climate models and global permafrost distribution, these results indicate, under conditions similar to mid-Pliocene Warm period (3.3-3.0 Ma), ~60% of alpine permafrost containing ~85 petagrams of carbon may be vulnerable to thawing compared to ~20% of circumarctic permafrost. This estimate highlights ~25% of permafrost carbon and the permafrost-climate feedback could originate in alpine areas.