Guillermo Murray-Tortarolo, Instituto de Investigaciones en Ecosistemas y Sustentabilidad
Benjamin Poulter, NASA Goddard Space Flight Center
Rodrigo Vargas, University of Delaware
Daniel Hayes, University of Maine
Anna M. Michalak, Carnegie Institution of Washington
Christopher A. Williams, Clark UniversityFollow
Lisamarie Windham-Myers, United States Geological Survey Western Region
Jonathan A. Wang, University of California, Irvine
Kimberly P. Wickland, United States Geological Survey
David Butman, University of Washington
Hanqin Tian, Boston College
Stephen Sitch, University of Exeter
Pierre Friedlingstein, University of Exeter
Mike O’Sullivan, University of Exeter
Peter Briggs, Commonwealth Scientific and Industrial Research Organization
Vivek Arora, Environment and Climate Change Canada
Danica Lombardozzi, National Center for Atmospheric Research
Atul K. Jain, University of Illinois Urbana-Champaign
Wenping Yuan, Sun Yat-Sen University
Roland Séférian, Université Fédérale Toulouse Midi-Pyrénées
Julia Nabel, Max Planck Institute for Biogeochemistry
Andy Wiltshire, Met Office
Almut Arneth, Karlsruher Institut für Technologie
Sebastian Lienert, University of Bern, Institute of Applied Physics
Sönke Zaehle, Max Planck Institute for Biogeochemistry
Vladislav Bastrikov, Laboratoire des Sciences du Climat et de l'Environnement
Daniel Goll, Université de Versailles Saint-Quentin-en-Yvelines
Nicolas Vuichard, Laboratoire des Sciences du Climat et de l'Environnement
Anthony Walker, ORNL Environmental Sciences Division
Etsushi Kato, The Institute of Applied Energy
Xu Yue, Nanjing University of Information Science & Technology
Zhen Zhang, University of Maryland, College Park

Document Type



Continental North America has been found to be a carbon (C) sink over recent decades by multiple studies employing a variety of estimation approaches. However, several key questions and uncertainties remain with these assessments. Here we used results from an ensemble of 19 state-of-the-art dynamic global vegetation models from the TRENDYv9 project to improve these estimates and study the drivers of its interannual variability. Our results show that North America has been a C sink with a magnitude of 0.37 ± 0.38 (mean and one standard deviation) PgC year−1 for the period 2000–2019 (0.31 and 0.44 PgC year−1 in each decade); split into 0.18 ± 0.12 PgC year−1 in Canada (0.15 and 0.20), 0.16 ± 0.17 in the United States (0.14 and 0.17), 0.02 ± 0.05 PgC year−1 in Mexico (0.02 and 0.02) and 0.01 ± 0.02 in Central America and the Caribbean (0.01 and 0.01). About 57% of the new C assimilated by terrestrial ecosystems is allocated into vegetation, 30% into soils, and 13% into litter. Losses of C due to fire account for 41% of the interannual variability of the mean net biome productivity for all North America in the model ensemble. Finally, we show that drought years (e.g., 2002) have the potential to shift the region to a small net C source in the simulations (−0.02 ± 0.46 PgC year−1). Our results highlight the importance of identifying the major drivers of the interannual variability of the continental-scale land C cycle along with the spatial distribution of local sink-source dynamics.

Supplementary file of supporting data also available for download.

Publication Title

Journal of Geophysical Research: Biogeosciences

Publication Date











carbon cycle, drought, magnitude, source-sink dynamics, spatial distribution, vegetation cove

Included in

Geography Commons



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