Empirical estimates of regional carbon budgets imply reduced global soil heterotrophic respiration

Philippe Ciais; Yitong Yao; Thomas Gasser; Alessandro Baccini; Yilong Wang; Ronny Lauerwald; Shushi Peng; Ana Bastos; Wei Li; Peter A Raymond; Josep G Canadell; Glen P Peters; Rob J Andres; Jinfeng Chang; Chao Yue; A Johannes Dolman; Vanessa Haverd; Jens Hartmann; Goulven Laruelle; Alexandra G Konings; Anthony W King; Yi Liu; Sebastiaan Luyssaert; Fabienne Maignan; Prabir K Patra; Anna Peregon; Pierre Regnier; Julia Pongratz; Benjamin Poulter; Anatoly Shvidenko; Riccardo Valentini; Rong Wang; Grégoire Broquet; Yi Yin; Jakob Zscheischler; Bertrand Guenet; Daniel S Goll; Ashley-P Ballantyne; Hui Yang; Chunjing Qiu; Dan Zhu

doi:10.1093/nsr/nwaa145

Empirical estimates of regional carbon budgets imply reduced global soil heterotrophic respiration

Natl Sci Rev. 2020 Jul 7;8(2):nwaa145. doi: 10.1093/nsr/nwaa145. eCollection 2021 Feb.

Authors

Philippe Ciais¹, Yitong Yao¹, Thomas Gasser², Alessandro Baccini³, Yilong Wang⁴, Ronny Lauerwald¹, Shushi Peng⁵, Ana Bastos⁶, Wei Li⁷, Peter A Raymond⁸, Josep G Canadell⁹, Glen P Peters¹⁰, Rob J Andres¹¹, Jinfeng Chang¹, Chao Yue¹, A Johannes Dolman¹², Vanessa Haverd¹³, Jens Hartmann¹⁴, Goulven Laruelle¹⁵, Alexandra G Konings¹⁶, Anthony W King¹¹, Yi Liu¹⁷, Sebastiaan Luyssaert¹⁸, Fabienne Maignan¹, Prabir K Patra¹⁹, Anna Peregon¹, Pierre Regnier¹⁵, Julia Pongratz¹⁵, Benjamin Poulter²⁰, Anatoly Shvidenko², Riccardo Valentini²¹, Rong Wang²², Grégoire Broquet¹, Yi Yin²³, Jakob Zscheischler²⁴, Bertrand Guenet¹, Daniel S Goll¹, Ashley-P Ballantyne²⁵, Hui Yang¹, Chunjing Qiu¹, Dan Zhu¹

Affiliations

¹ Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ-UPSACLAY, Gif sur Yvette 91191, France.
² International Institute for Applied Systems Analysis (IIASA), Laxenburg A-2361, Austria.
³ Woods Hole Research Center, Falmouth, MA 02540, USA.
⁴ The Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100871, China.
⁵ Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
⁶ Department für Geographie, Ludwig-Maximilians-Universität München, München D-80333, Germany.
⁷ Department of Earth System Science, Tsinghua University, Beijing 100084, China.
⁸ Yale School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA.
⁹ Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra ACT 2601, Australia.
¹⁰ CICERO Center for International Climate Research, Oslo 0349, Norway.
¹¹ Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
¹² Department of Earth Science, Vrije Universiteit Amsterdam, Amsterdam HV 1081, The Netherlands.
¹³ CSIRO Oceans and Atmosphere, Canberra ACT 2601, Australia.
¹⁴ Institute for Geology, CEN-Center for Earth System Research and Sustainability, University of Hamburg, Hamburg D-20146, Germany.
¹⁵ Department Geoscience, Environment & Society, Université Libre de Bruxelles, Bruxelles 1050, Belgium.
¹⁶ Department of Earth System Science, Stanford University, Stanford, CA 94305, USA.
¹⁷ School of Geographical Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China.
¹⁸ Department of Ecological Sciences, Vrije Universiteit Amsterdam, Amsterdam HV 1081, The Netherlands.
¹⁹ Research Institute for Global Change, JAMSTEC, Kanagawa 236-0001, Japan.
²⁰ NASA Goddard Space Flight Center, Biospheric Sciences Lab., Greenbelt, MD 20771, USA.
²¹ Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), University of Tuscia, Viterbo 01100, Italy.
²² Department of Environmental Science and Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
²³ Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
²⁴ Climate and Environmental Physics and Oeschger Centre for Climate Change Research, University of Bern, Bern 3012, Switzerland.
²⁵ Department of Ecosystem and Conservation Science, University of Montana, Missoula, MT 59801, USA.

Abstract

Resolving regional carbon budgets is critical for informing land-based mitigation policy. For nine regions covering nearly the whole globe, we collected inventory estimates of carbon-stock changes complemented by satellite estimates of biomass changes where inventory data are missing. The net land-atmospheric carbon exchange (NEE) was calculated by taking the sum of the carbon-stock change and lateral carbon fluxes from crop and wood trade, and riverine-carbon export to the ocean. Summing up NEE from all regions, we obtained a global 'bottom-up' NEE for net land anthropogenic CO₂ uptake of -2.2 ± 0.6 PgC yr^-1 consistent with the independent top-down NEE from the global atmospheric carbon budget during 2000-2009. This estimate is so far the most comprehensive global bottom-up carbon budget accounting, which set up an important milestone for global carbon-cycle studies. By decomposing NEE into component fluxes, we found that global soil heterotrophic respiration amounts to a source of CO₂ of 39 PgC yr^-1 with an interquartile of 33-46 PgC yr^-1-a much smaller portion of net primary productivity than previously reported.

Keywords: carbon budget; human appropriation of ecosystems; soil carbon.