Permafrost Region Greenhouse Gas Budgets Suggest a Weak CO<sub>2</sub> Sink and CH<sub>4</sub> and N<sub>2</sub>O Sources, But Magnitudes Differ Between Top‐Down and Bottom‐Up Methods
2024
Hugelius, G. | Ramage, J. | Burke, E. | Chatterjee, A. | Smallman, T, L | Aalto, T. | Bastos, A. | Biasi, C. | Canadell, J, G | Chandra, N. | Chevallier, F. | Ciais, P. | Chang, J. | Feng, L. | Jones, M, W | Kleinen, T. | Kuhn, M. | Lauerwald, R. | Liu, J. | López‐blanco, E | Luijkx, I, T | Marushchak, M, E | Natali, S, M | Niwa, Y. | Olefeldt, D. | Palmer, P, I | Patra, P, K | Peters, W. | Potter, S. | Poulter, B. | Rogers, B, M | Riley, W, J | Saunois, M. | Schuur, E, a G | Thompson, R, L | Treat, C. | Tsuruta, A. | Turetsky, M, R | Voigt, C. | Watts, J. | Zhu, Q. | Zheng, B. | Bolin Centre for Climate Research ; Stockholm University | Stockholm University | Met Office Hadley Centre (MOHC) ; United Kingdom Met Office [Exeter] | California Institute of Technology (CALTECH) | The University of Edinburgh | Finnish Meteorological Institute (FMI) | Max Planck Institute for Biogeochemistry (MPI-BGC) ; Max-Planck-Gesellschaft | Finland and University of Innsbruck | CSIRO Environment Business Unit ; Commonwealth Scientific and Industrial Research Organisation [Australia] (CSIRO) | Research Institute for Global Change (RIGC) ; Japan Agency for Marine-Earth Science and Technology (JAMSTEC) | 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) | Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV) ; 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)-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) | Zhejiang Normal University | University of East Anglia [Norwich] (UEA) | Max Planck Institute for Meteorology (MPI-M) ; Max-Planck-Gesellschaft | Department of Earth Sciences, University of New Hampshire | Université Paris-Saclay | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Greenland Institute of Natural Resources (GINR) | Wageningen University and Research [Wageningen] (WUR) | University of Eastern Finland | Woodwell Climate Research Center | National Institute for Environmental Studies (NIES) | University of Alberta | Research Institute for Humanity and Nature (RIHN) | Biospheric Sciences Laboratory ; NASA Goddard Space Flight Center (GSFC) | Lawrence Berkeley National Laboratory [Berkeley] (LBNL) | Center for Ecosystem Science and Society (ECOSS) ; Northern Arizona University [Flagstaff] | Norsk Institutt for Luftforskning (NILU) | Center for Polar and Marine Research | University of Colorado [Boulder] | Tsinghua University [Beijing] (THU)
International audience
显示更多 [+] 显示较少 [-]英语. Large stocks of soil carbon (C) and nitrogen (N) in northern permafrost soils are vulnerable to remobilization under climate change. However, there are large uncertainties in present-day greenhouse gas (GHG) budgets. We compare bottom-up (data-driven upscaling and process-based models) and top-down (atmospheric inversion models) budgets of carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) as well as lateral fluxes of C and N across the region over 2000-2020. Bottom-up approaches estimate higher land-to-atmosphere fluxes for all GHGs. Both bottom-up and top-down approaches show a sink of CO 2 in natural ecosystems (bottom-up: 29 ( 709, 455), top-down: 587 ( 862, 312) Tg CO 2 -C yr 1 ) and sources of CH 4 (bottom-up: 38 (22, 53), top-down: 15 (11, 18) Tg CH 4 -C yr 1 ) and N 2 O (bottom-up: 0.7 (0.1, 1.3), top-down: 0.09 ( 0.19, 0.37) Tg N 2 O-N yr 1 ). The combined global warming potential of all three gases (GWP-100) cannot be distinguished from neutral. Over shorter timescales (GWP-20), the region is a net GHG source because CH 4 dominates the total forcing. The net CO 2 sink in Boreal forests and wetlands is largely offset by fires and inland water CO 2 emissions as well as CH 4 emissions from wetlands and inland waters,
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