Title: Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO<sub>2</sub>
Abstract: New PhytologistVolume 229, Issue 5 p. 2413-2445 Tansley reviewFree Access Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2 Anthony P. Walker, Corresponding Author Anthony P. Walker [email protected] orcid.org/0000-0003-0557-5594 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USA Author for correspondence: Anthony P. Walker Email:[email protected] for more papers by this authorMartin G. De Kauwe, Martin G. De Kauwe orcid.org/0000-0002-3399-9098 ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052 Australia Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052 Australia Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052 AustraliaSearch for more papers by this authorAna Bastos, Ana Bastos orcid.org/0000-0002-7368-7806 Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333 GermanySearch for more papers by this authorSoumaya Belmecheri, Soumaya Belmecheri orcid.org/0000-0003-1258-2741 Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorKaterina Georgiou, Katerina Georgiou orcid.org/0000-0002-2819-3292 Department of Earth System Science, Stanford University, Stanford, CA, 94305 USASearch for more papers by this authorRalph F. Keeling, Ralph F. Keeling orcid.org/0000-0002-9749-2253 Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92093 USASearch for more papers by this authorSean M. McMahon, Sean M. McMahon orcid.org/0000-0001-8302-6908 Smithsonian Environmental Research Center, Edgewater, MD, 21037 USASearch for more papers by this authorBelinda E. Medlyn, Belinda E. Medlyn orcid.org/0000-0001-5728-9827 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorDavid J. P. Moore, David J. P. Moore orcid.org/0000-0002-6462-3288 School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721 USASearch for more papers by this authorRichard J. Norby, Richard J. Norby orcid.org/0000-0002-0238-9828 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorSönke Zaehle, Sönke Zaehle orcid.org/0000-0001-5602-7956 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorKristina J. Anderson-Teixeira, Kristina J. Anderson-Teixeira orcid.org/0000-0001-8461-9713 Conservation Ecology Center, Smithsonian Conservation Biology Institute, MRC 5535, Front Royal, VA, 22630 USA Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Panama City, PanamaSearch for more papers by this authorGiovanna Battipaglia, Giovanna Battipaglia orcid.org/0000-0003-1741-3509 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania, Caserta, 81100 ItalySearch for more papers by this authorRoel J. W. Brienen, Roel J. W. Brienen orcid.org/0000-0002-5397-5755 School of Geography, University of Leeds, Leeds, LS6 9JT UKSearch for more papers by this authorKristine G. Cabugao, Kristine G. Cabugao Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorMaxime Cailleret, Maxime Cailleret orcid.org/0000-0001-6561-1943 INRAE, UMR RECOVER, Aix-Marseille Université, 3275 route de Cézanne, Aix-en-Provence Cedex 5, 13182 France Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, SwitzerlandSearch for more papers by this authorElliott Campbell, Elliott Campbell Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106 USASearch for more papers by this authorJosep G. Canadell, Josep G. Canadell orcid.org/0000-0002-8788-3218 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorPhilippe Ciais, Philippe Ciais orcid.org/0000-0001-8560-4943 Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, F-91191 FranceSearch for more papers by this authorMatthew E. Craig, Matthew E. Craig orcid.org/0000-0002-8890-7920 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorDavid S. Ellsworth, David S. Ellsworth orcid.org/0000-0002-9699-2272 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorGraham D. Farquhar, Graham D. Farquhar orcid.org/0000-0002-7065-1971 Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorSimone Fatichi, Simone Fatichi orcid.org/0000-0003-1361-6659 Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576 Singapore Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini Platz 5, Zurich, 8093 SwitzerlandSearch for more papers by this authorJoshua B. Fisher, Joshua B. Fisher orcid.org/0000-0003-4734-9085 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA, 91109 USASearch for more papers by this authorDavid C. Frank, David C. Frank Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorHeather Graven, Heather Graven orcid.org/0000-0003-3934-2502 Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ UKSearch for more papers by this authorLianhong Gu, Lianhong Gu orcid.org/0000-0001-5756-8738 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorVanessa Haverd, Vanessa Haverd orcid.org/0000-0003-4359-5895 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorKelly Heilman, Kelly Heilman orcid.org/0000-0001-5932-1317 Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorMartin Heimann, Martin Heimann orcid.org/0000-0001-6296-5113 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorBruce A. Hungate, Bruce A. Hungate orcid.org/0000-0002-7337-1887 Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011 USASearch for more papers by this authorColleen M. Iversen, Colleen M. Iversen orcid.org/0000-0001-8293-3450 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorFortunat Joos, Fortunat Joos orcid.org/0000-0002-9483-6030 Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstr. 5, Bern, CH-3012 SwitzerlandSearch for more papers by this authorMingkai Jiang, Mingkai Jiang orcid.org/0000-0002-9982-9518 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorTrevor F. Keenan, Trevor F. Keenan orcid.org/0000-0002-3347-0258 Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, 94720 USA Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720 USASearch for more papers by this authorJürgen Knauer, Jürgen Knauer orcid.org/0000-0002-4947-7067 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorChristian Körner, Christian Körner orcid.org/0000-0001-7768-7638 Department of Environmental Sciences, Botany, University of Basel, Basel, 4056 SwitzerlandSearch for more papers by this authorVictor O. Leshyk, Victor O. Leshyk Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011 USASearch for more papers by this authorSebastian Leuzinger, Sebastian Leuzinger orcid.org/0000-0001-9306-5281 School of Science, Auckland University of Technology, Auckland, 1142 New ZealandSearch for more papers by this authorYao Liu, Yao Liu orcid.org/0000-0003-2783-3291 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorNatasha MacBean, Natasha MacBean orcid.org/0000-0001-6797-4836 Department of Geography, Indiana University, Bloomington, IN, 47405 USASearch for more papers by this authorYadvinder Malhi, Yadvinder Malhi orcid.org/0000-0002-3503-4783 School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY UKSearch for more papers by this authorTim R. McVicar, Tim R. McVicar orcid.org/0000-0002-0877-8285 CSIRO Land and Water, GPO Box 1700, Canberra, ACT, 2601 Australia Australian Research Council Centre of Excellence for Climate Extremes, 142 Mills Rd, Australian National University, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorJosep Penuelas, Josep Penuelas orcid.org/0000-0002-7215-0150 CSIC, Global Ecology CREAF-CSIC-UAB, Bellaterra, Barcelona, Catalonia, 08193 Spain CREAF, Cerdanyola del Vallès, Barcelona, Catalonia, 08193 SpainSearch for more papers by this authorJulia Pongratz, Julia Pongratz orcid.org/0000-0003-0372-3960 Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333 Germany Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg, GermanySearch for more papers by this authorA. Shafer Powell, A. Shafer Powell orcid.org/0000-0002-9622-0061 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorTerhi Riutta, Terhi Riutta School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY UKSearch for more papers by this authorManon E. B. Sabot, Manon E. B. Sabot orcid.org/0000-0002-9440-4553 ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052 Australia Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052 Australia Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052 AustraliaSearch for more papers by this authorJuergen Schleucher, Juergen Schleucher orcid.org/0000-0002-4815-3466 Department of Medical Biochemistry & Biophysics, Umeå University, Umea, 901 87 SwedenSearch for more papers by this authorStephen Sitch, Stephen Sitch orcid.org/0000-0003-1821-8561 College of Life and Environmental Sciences, University of Exeter, Exeter, Laver Building EX4 4QF UKSearch for more papers by this authorWilliam K. Smith, William K. Smith orcid.org/0000-0002-5785-6489 School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721 USASearch for more papers by this authorBenjamin Sulman, Benjamin Sulman orcid.org/0000-0002-3265-6691 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorBenton Taylor, Benton Taylor orcid.org/0000-0002-9834-9192 Smithsonian Environmental Research Center, Edgewater, MD, 21037 USASearch for more papers by this authorCésar Terrer, César Terrer orcid.org/0000-0002-5479-3486 Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550 USASearch for more papers by this authorMargaret S. Torn, Margaret S. Torn orcid.org/0000-0002-8174-0099 Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720 USASearch for more papers by this authorKathleen K. Treseder, Kathleen K. Treseder orcid.org/0000-0003-2847-6935 Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA, 92697 USASearch for more papers by this authorAnna T. Trugman, Anna T. Trugman orcid.org/0000-0002-7903-9711 Department of Geography, 1832 Ellison Hall, Santa Barbara, CA, 93016 USASearch for more papers by this authorSusan E. Trumbore, Susan E. Trumbore orcid.org/0000-0003-3885-6202 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorPhillip J. van Mantgem, Phillip J. van Mantgem orcid.org/0000-0002-3068-9422 U.S. Geological Survey, Western Ecological Research Center, Arcata, CA, 95521 USASearch for more papers by this authorSteve L. Voelker, Steve L. Voelker orcid.org/0000-0002-0110-3381 Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210 USASearch for more papers by this authorMary E. Whelan, Mary E. Whelan orcid.org/0000-0002-2067-1835 Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ, 08901 USASearch for more papers by this authorPieter A. Zuidema, Pieter A. Zuidema orcid.org/0000-0001-8100-1168 Forest Ecology and Forest Management group, Wageningen University, PO Box 47, Wageningen, 6700 AA the NetherlandsSearch for more papers by this author Anthony P. Walker, Corresponding Author Anthony P. Walker [email protected] orcid.org/0000-0003-0557-5594 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USA Author for correspondence: Anthony P. Walker Email:[email protected] for more papers by this authorMartin G. De Kauwe, Martin G. De Kauwe orcid.org/0000-0002-3399-9098 ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052 Australia Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052 Australia Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052 AustraliaSearch for more papers by this authorAna Bastos, Ana Bastos orcid.org/0000-0002-7368-7806 Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333 GermanySearch for more papers by this authorSoumaya Belmecheri, Soumaya Belmecheri orcid.org/0000-0003-1258-2741 Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorKaterina Georgiou, Katerina Georgiou orcid.org/0000-0002-2819-3292 Department of Earth System Science, Stanford University, Stanford, CA, 94305 USASearch for more papers by this authorRalph F. Keeling, Ralph F. Keeling orcid.org/0000-0002-9749-2253 Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92093 USASearch for more papers by this authorSean M. McMahon, Sean M. McMahon orcid.org/0000-0001-8302-6908 Smithsonian Environmental Research Center, Edgewater, MD, 21037 USASearch for more papers by this authorBelinda E. Medlyn, Belinda E. Medlyn orcid.org/0000-0001-5728-9827 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorDavid J. P. Moore, David J. P. Moore orcid.org/0000-0002-6462-3288 School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721 USASearch for more papers by this authorRichard J. Norby, Richard J. Norby orcid.org/0000-0002-0238-9828 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorSönke Zaehle, Sönke Zaehle orcid.org/0000-0001-5602-7956 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorKristina J. Anderson-Teixeira, Kristina J. Anderson-Teixeira orcid.org/0000-0001-8461-9713 Conservation Ecology Center, Smithsonian Conservation Biology Institute, MRC 5535, Front Royal, VA, 22630 USA Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Panama City, PanamaSearch for more papers by this authorGiovanna Battipaglia, Giovanna Battipaglia orcid.org/0000-0003-1741-3509 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania, Caserta, 81100 ItalySearch for more papers by this authorRoel J. W. Brienen, Roel J. W. Brienen orcid.org/0000-0002-5397-5755 School of Geography, University of Leeds, Leeds, LS6 9JT UKSearch for more papers by this authorKristine G. Cabugao, Kristine G. Cabugao Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorMaxime Cailleret, Maxime Cailleret orcid.org/0000-0001-6561-1943 INRAE, UMR RECOVER, Aix-Marseille Université, 3275 route de Cézanne, Aix-en-Provence Cedex 5, 13182 France Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, SwitzerlandSearch for more papers by this authorElliott Campbell, Elliott Campbell Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106 USASearch for more papers by this authorJosep G. Canadell, Josep G. Canadell orcid.org/0000-0002-8788-3218 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorPhilippe Ciais, Philippe Ciais orcid.org/0000-0001-8560-4943 Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, F-91191 FranceSearch for more papers by this authorMatthew E. Craig, Matthew E. Craig orcid.org/0000-0002-8890-7920 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorDavid S. Ellsworth, David S. Ellsworth orcid.org/0000-0002-9699-2272 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorGraham D. Farquhar, Graham D. Farquhar orcid.org/0000-0002-7065-1971 Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorSimone Fatichi, Simone Fatichi orcid.org/0000-0003-1361-6659 Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576 Singapore Institute of Environmental Engineering, ETH Zurich, Stefano-Franscini Platz 5, Zurich, 8093 SwitzerlandSearch for more papers by this authorJoshua B. Fisher, Joshua B. Fisher orcid.org/0000-0003-4734-9085 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA, 91109 USASearch for more papers by this authorDavid C. Frank, David C. Frank Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorHeather Graven, Heather Graven orcid.org/0000-0003-3934-2502 Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ UKSearch for more papers by this authorLianhong Gu, Lianhong Gu orcid.org/0000-0001-5756-8738 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorVanessa Haverd, Vanessa Haverd orcid.org/0000-0003-4359-5895 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorKelly Heilman, Kelly Heilman orcid.org/0000-0001-5932-1317 Laboratory of Tree Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721 USASearch for more papers by this authorMartin Heimann, Martin Heimann orcid.org/0000-0001-6296-5113 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorBruce A. Hungate, Bruce A. Hungate orcid.org/0000-0002-7337-1887 Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011 USASearch for more papers by this authorColleen M. Iversen, Colleen M. Iversen orcid.org/0000-0001-8293-3450 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorFortunat Joos, Fortunat Joos orcid.org/0000-0002-9483-6030 Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstr. 5, Bern, CH-3012 SwitzerlandSearch for more papers by this authorMingkai Jiang, Mingkai Jiang orcid.org/0000-0002-9982-9518 Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751 AustraliaSearch for more papers by this authorTrevor F. Keenan, Trevor F. Keenan orcid.org/0000-0002-3347-0258 Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, 94720 USA Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720 USASearch for more papers by this authorJürgen Knauer, Jürgen Knauer orcid.org/0000-0002-4947-7067 CSIRO Oceans and Atmosphere, GPO Box 1700, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorChristian Körner, Christian Körner orcid.org/0000-0001-7768-7638 Department of Environmental Sciences, Botany, University of Basel, Basel, 4056 SwitzerlandSearch for more papers by this authorVictor O. Leshyk, Victor O. Leshyk Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011 USASearch for more papers by this authorSebastian Leuzinger, Sebastian Leuzinger orcid.org/0000-0001-9306-5281 School of Science, Auckland University of Technology, Auckland, 1142 New ZealandSearch for more papers by this authorYao Liu, Yao Liu orcid.org/0000-0003-2783-3291 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorNatasha MacBean, Natasha MacBean orcid.org/0000-0001-6797-4836 Department of Geography, Indiana University, Bloomington, IN, 47405 USASearch for more papers by this authorYadvinder Malhi, Yadvinder Malhi orcid.org/0000-0002-3503-4783 School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY UKSearch for more papers by this authorTim R. McVicar, Tim R. McVicar orcid.org/0000-0002-0877-8285 CSIRO Land and Water, GPO Box 1700, Canberra, ACT, 2601 Australia Australian Research Council Centre of Excellence for Climate Extremes, 142 Mills Rd, Australian National University, Canberra, ACT, 2601 AustraliaSearch for more papers by this authorJosep Penuelas, Josep Penuelas orcid.org/0000-0002-7215-0150 CSIC, Global Ecology CREAF-CSIC-UAB, Bellaterra, Barcelona, Catalonia, 08193 Spain CREAF, Cerdanyola del Vallès, Barcelona, Catalonia, 08193 SpainSearch for more papers by this authorJulia Pongratz, Julia Pongratz orcid.org/0000-0003-0372-3960 Ludwig Maximilians University of Munich, Luisenstr. 37, Munich, 80333 Germany Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg, GermanySearch for more papers by this authorA. Shafer Powell, A. Shafer Powell orcid.org/0000-0002-9622-0061 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorTerhi Riutta, Terhi Riutta School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY UKSearch for more papers by this authorManon E. B. Sabot, Manon E. B. Sabot orcid.org/0000-0002-9440-4553 ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, 2052 Australia Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052 Australia Evolution and Ecology Research Centre, University of New South Wales, Sydney, NSW, 2052 AustraliaSearch for more papers by this authorJuergen Schleucher, Juergen Schleucher orcid.org/0000-0002-4815-3466 Department of Medical Biochemistry & Biophysics, Umeå University, Umea, 901 87 SwedenSearch for more papers by this authorStephen Sitch, Stephen Sitch orcid.org/0000-0003-1821-8561 College of Life and Environmental Sciences, University of Exeter, Exeter, Laver Building EX4 4QF UKSearch for more papers by this authorWilliam K. Smith, William K. Smith orcid.org/0000-0002-5785-6489 School of Natural Resources and the Environment, 1064 East Lowell Street, Tucson, AZ, 85721 USASearch for more papers by this authorBenjamin Sulman, Benjamin Sulman orcid.org/0000-0002-3265-6691 Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USASearch for more papers by this authorBenton Taylor, Benton Taylor orcid.org/0000-0002-9834-9192 Smithsonian Environmental Research Center, Edgewater, MD, 21037 USASearch for more papers by this authorCésar Terrer, César Terrer orcid.org/0000-0002-5479-3486 Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550 USASearch for more papers by this authorMargaret S. Torn, Margaret S. Torn orcid.org/0000-0002-8174-0099 Earth and Environmental Sciences Area, Lawrence Berkeley National Lab., Berkeley, CA, 94720 USASearch for more papers by this authorKathleen K. Treseder, Kathleen K. Treseder orcid.org/0000-0003-2847-6935 Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA, 92697 USASearch for more papers by this authorAnna T. Trugman, Anna T. Trugman orcid.org/0000-0002-7903-9711 Department of Geography, 1832 Ellison Hall, Santa Barbara, CA, 93016 USASearch for more papers by this authorSusan E. Trumbore, Susan E. Trumbore orcid.org/0000-0003-3885-6202 Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, Jena, 07745 GermanySearch for more papers by this authorPhillip J. van Mantgem, Phillip J. van Mantgem orcid.org/0000-0002-3068-9422 U.S. Geological Survey, Western Ecological Research Center, Arcata, CA, 95521 USASearch for more papers by this authorSteve L. Voelker, Steve L. Voelker orcid.org/0000-0002-0110-3381 Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210 USASearch for more papers by this authorMary E. Whelan, Mary E. Whelan orcid.org/0000-0002-2067-1835 Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ, 08901 USASearch for more papers by this authorPieter A. Zuidema, Pieter A. Zuidema orcid.org/0000-0001-8100-1168 Forest Ecology and Forest Management group, Wageningen University, PO Box 47, Wageningen, 6700 AA the NetherlandsSearch for more papers by this author First published: 12 August 2020 https://doi.org/10.1111/nph.16866Citations: 45 See also the Commentary on this article by Way et al., 229: 2383–2385. AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Summary Atmospheric carbon dioxide concentration ([CO2]) is increasing, which increases leaf-scale photosynthesis and intrinsic water-use efficiency. These direct responses have the potential to increase plant growth, vegetation biomass, and soil organic matter; transferring carbon from the atmosphere into terrestrial ecosystems (a carbon sink). A substantial global terrestrial carbon sink would slow the rate of [CO2] increase and thus climate change. However, ecosystem CO2 responses are complex or confounded by concurrent changes in multiple agents of global change and evidence for a [CO2]-driven terrestrial carbon sink can appear contradictory. Here we synthesize theory and broad, multidisciplinary evidence for the effects of increasing [CO2] (iCO2) on the global terrestrial carbon sink. Evidence suggests a substantial increase in global photosynthesis since pre-industrial times. Established theory, supported by experiments, indicates that iCO2 is likely responsible for about half of the increase. Global carbon budgeting, atmospheric data, and forest inventories indicate a historical carbon sink, and these apparent iCO2 responses are high in comparison to experiments and predictions from theory. Plant mortality and soil carbon iCO2 responses are highly uncertain. In conclusion, a range of evidence supports a positive terrestrial carbon sink in response to iCO2, albeit with uncertain magnitude and strong suggestion of a role for additional agents of global change. Video summary Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2 by Walker et al. Contents Summary 2414 I. Introduction 2415 II. Theory – a hierarchy of mechanism 2416 III. The evidence 2422 IV.