National CO2 budgets (2015-2020) inferred from atmospheric CO2 observations in support of the global stocktake


Brendan Byrne, California Institute of Technology
David F. Baker, Colorado State University
Sourish Basu, NASA Goddard Space Flight Center
Michael Bertolacci, University of Wollongong
Kevin W. Bowman, California Institute of Technology
Dustin Carroll, California Institute of Technology
Abhishek Chatterjee, California Institute of Technology
Frédéric Chevallier, Université de Versailles Saint-Quentin-en-Yvelines
Philippe Ciais, Université de Versailles Saint-Quentin-en-Yvelines
Noel Cressie, California Institute of Technology
David Crisp, California Institute of Technology
Sean Crowell, University of Oklahoma
Feng Deng, University of Toronto
Zhu Deng, Tsinghua University
Nicholas M. Deutscher, Faculty of Science, Medicine and Health
Manvendra K. Dubey, Los Alamos National Laboratory
Sha Feng, Pacific Northwest National Laboratory
Omaira E. García, State Meteorological Agency of Spain (AEMet)
David W.T. Griffith, Faculty of Science, Medicine and Health
Benedikt Herkommer, Karlsruher Institut für Technologie
Lei Hu, National Oceanic and Atmospheric Administration
Andrew R. Jacobson, National Oceanic and Atmospheric Administration
Rajesh Janardanan, National Institute for Environmental Studies of Japan
Sujong Jeong, Seoul National University
Matthew S. Johnson, NASA Ames Research Center
Dylan B.A. Jones, University of Toronto
Rigel Kivi, Finnish Meteorological Institute
Junjie Liu, California Institute of Technology
Zhiqiang Liu, Institute of Atmospheric Physics Chinese Academy of Sciences

Publication Name

Earth System Science Data


Accurate accounting of emissions and removals of CO2 is critical for the planning and verification of emission reduction targets in support of the Paris Agreement. Here, we present a pilot dataset of country-specific net carbon exchange (NCE; fossil plus terrestrial ecosystem fluxes) and terrestrial carbon stock changes aimed at informing countries' carbon budgets. These estimates are based on "top-down"NCE outputs from the v10 Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble of inverse modeling groups conducted standardized experiments assimilating OCO-2 column-Averaged dry-Air mole fraction (XCO2) retrievals (ACOS v10), in situ CO2 measurements or combinations of these data. The v10 OCO-2 MIP NCE estimates are combined with "bottom-up"estimates of fossil fuel emissions and lateral carbon fluxes to estimate changes in terrestrial carbon stocks, which are impacted by anthropogenic and natural drivers. These flux and stock change estimates are reported annually (2015-2020) as both a global 1gg×g1g gridded dataset and a country-level dataset and are available for download from the Committee on Earth Observation Satellites' (CEOS) website: 10.48588/npf6-sw92 . Across the v10 OCO-2 MIP experiments, we obtain increases in the ensemble median terrestrial carbon stocks of 3.29-4.58gPgCO2yr-1 (0.90-1.25gPgCyr-1). This is a result of broad increases in terrestrial carbon stocks across the northern extratropics, while the tropics generally have stock losses but with considerable regional variability and differences between v10 OCO-2 MIP experiments. We discuss the state of the science for tracking emissions and removals using top-down methods, including current limitations and future developments towards top-down monitoring and verification systems.

Open Access Status

This publication may be available as open access





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Funding Sponsor

National Aeronautics and Space Administration



Link to publisher version (DOI)