Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: McGuire,A.D., Lawrence, D.M., Koven, C., Clein, J.S., Burke, E., Chen, G., Jafarov, E., MacDougall, A.H., Marchenko, S., Nicolsky, D., Peng, S., Rinke, A., Ciais, P., Gouttevin, I., Hayes, D.J., Ji, D., Krinner, G., Moore, J.C., Romanovsky, V., Schadel, C., Schaefer, K., Schuur, E.A.G., Zhuang, Q.
• Other Authors: USGS ALASKA COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT UNIVERSITY OF ALASKA FAIRBANKS USA, CLIMATE AND GLOBAL DYNAMICS LABORATORY NATIONAL CENTER FOR ATMOSPHERIC RESEARCH BOULDER USA, CLIMATE AND ECOSYSTEM SCIENCES DIVISION LAWRENCE BERKELEY NATIONAL LABORATORY USA, INSTITUTE OF ARCTIC BIOLOGY UNIVERSITY OF ALASKA FAIRBANKS USA, MET OFFICE HADLEY CENTRE EXETER GBR, ENVIRONMENTAL SCIENCES DIVISION OAK RIDGE NATIONAL LABORATORY OAK RIDGE USA, EARTH AND ENVIRONMENTAL SCIENCES DIVISION LOS ALAMOS NATIONAL LABORATORY LOS ALAMOS USA, DEPARTMENT OF EARTH SCIENCES ST FRANCIS XAVIER UNIVERSITY ANTIGONISH CAN, GEOPHYSICAL INSTITUTE UNIVERSITY OF ALASKA FAIRBANKS USA, LABORATOIRE DES SCIENCES DU CLIMAT ET DE L'ENVIRONNEMENT COMMISSARIAT A L'ENERGIE ATOMIQUE CNRS UNIVERSITE DE VERSAILLES SAINT QUENTIN EN YVELINES UMR8212 GIF SUR YVETTE FRA, ALFRED WEGENER INSTITUTE HELMHOLTZ CENTRE FOR POLAR AND MARINE RESEARCH POTSDAM DEU, INSTITUT DES GEOSCIENCES DE L'ENVIRONMENT UNIVERSITE GRENOBLE ALPES CNRS GRENOBLE FRA, COLLEGE OF GLOBAL CHANGE AND EARTH SYSTEM SCIENCE BEIJING NORMAL UNIVERSITY BEIJING CHN, CENTER FOR ECOSYSTEM SCIENCE AND SOCIETY NORTHERN ARIZONA UNIVERSITY FLAGSTAFF USA, NATIONAL SNOW AND ICE DATA CENTER UNIVERSITY OF COLORADO BOULDER USA, DEPARTMENT OF EARTH ATMOSPHERIC AND PLANETARY SCIENCES PURDUE UNIVERSITY WEST LAFAYETTE USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: CARBONE; NEIGE; CHANGEMENT CLIMATIQUE; carbon; snow; climatic change; permafrost
• Online Access: https://irsteadoc.irstea.fr/cemoa/PUB00060051

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon-climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km2 for the RCP4.5 climate and between 6 and 16 million km2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (1015-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon-climate feedback.