Highly restricted near-surface permafrost extent during the mid-Pliocene warm period

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Guo, Donglin, Wang, Huijun, Romanovsky, Vladimir E., Haywood, Alan M., Pepin, Nick C., Salzmann, Ulrich, Sun, Jianqi, Yan, Qing, Zhang, Zhongshi, Li, Xiangyu, Otto-Bliesner, Bette L., Feng, Ran, Lohmann, Gerrit, Stepanek, Christian, Abe-Ouchi, Ayako, Chan, Wing Le, Peltier, William Richard, Chandan, Deepak, von der Heydt, Anna S., Contoux, Camille, Chandler, Mark A., Tan, Ning, Zhang, Qiong, Hunter, Stephen J., Kamae, Youichi
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Helmholtz Climate Initiative REKLIM; National Science Foundation, NSF; National Center for Atmospheric Research, NCAR, (1814029, 1832238, 1852977); National Natural Science Foundation of China, NSFC, (41991281, 42088101, 42275027); Chinese Academy of Sciences, CAS, (xbzg-zdsys-202102); Helmholtz Association
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDV]Life Sciences [q-bio]; Arctic; Greenland; Arctic Archipelago; permafrost
• Online Access: https://hal.science/hal-04229527; https://doi.org/10.1073/pnas.2301954120

International audience Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. Studies of how permafrost responded historically during Earth’s past warm periods are helpful in exploring potential future permafrost behavior and to evaluate the uncertainty of future permafrost change projections. Here, we combine a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near-surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere during the mid-Pliocene warm period (mPWP, ~3.264 to 3.025 Ma). This period shares similarities with the projected future climate. Constrained by proxy-based surface air temperature records, our simulations demonstrate that near-surface permafrost was highly spatially restricted during the mPWP and was 93 ± 3% smaller than the preindustrial extent. Near-surface permafrost was present only in the eastern Siberian uplands, Canadian high Arctic Archipelago, and northernmost Greenland. The simulations are similar to near-surface permafrost changes projected for the end of this century under the SSP5-8.5 scenario and provide a perspective on the potential permafrost behavior that may be expected in a warmer world. Copyright