Global Carbon Budget 2022

Abstract

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b).

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Affiliated Institutions

• Institut Pierre-Simon Laplace FR
• National Institute for Environmental Studies JP
• Jet Propulsion Laboratory US
• NSF NCAR Climate and Global Dynamics Laboratory US
• National Oceanography Centre GB
• Sorbonne Université FR
• University of Exeter GB
• Wageningen University & Research NL
• Meteorological Research Institute
• University of Groningen NL
• Karlsruhe Institute of Technology DE
• Cooperative Institute for Research in Environmental Sciences US
• University of Reading GB
• Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung DE
• Oeschger Centre for Climate Change Research CH
• Ludwig-Maximilians-Universität München DE
• Japan Fisheries Research and Education Agency JP
• CEA Paris-Saclay FR
• University of Edinburgh GB
• NORCE Research AS
• Centre National de la Recherche Scientifique FR
• Appalachian State University US
• Met Office GB
• University of Illinois Urbana-Champaign US
• GEOMAR Helmholtz Centre for Ocean Research Kiel DE
• Chinese Academy of Sciences CN
• Utrecht University NL
• Météo-France FR
• University of East Anglia GB
• CSIRO Oceans and Atmosphere AU
• Forest Institute US
• Food and Agriculture Organization of the United Nations IT
• Institut de Recherche pour le Développement FR
• Institute of Tibetan Plateau Research CN
• Leibniz Institute for Baltic Sea Research Warnemünde DE
• Columbia University US
• Joint Research Centre IT
• Tsinghua University CN
• Western Sydney University AU
• Vrije Universiteit Amsterdam NL
• Tyndall Centre GB
• Boston College US
• Université Paris-Saclay FR
• Max Planck Institute for Biogeochemistry DE
• Woodwell Climate Research Center US
• Flanders Marine Institute BE
• Université Paris Sciences et Lettres FR
• Commissariat à l'Énergie Atomique et aux Énergies Alternatives FR
• NOAA Pacific Marine Environmental Laboratory US
• National Oceanic and Atmospheric Administration US
• Hakai Institute
• Lamont-Doherty Earth Observatory US
• NSF National Center for Atmospheric Research US
• Norwich Research Park GB
• Sheldon Jackson College US
• Australian Antarctic Division AU
• École Polytechnique FR
• University of Colorado Boulder US
• Université de Versailles Saint-Quentin-en-Yvelines FR
• Laboratoire des Sciences du Climat et de l'Environnement FR
• Environment and Climate Change Canada CA
• Bjerknes Centre for Climate Research
• International Institute for Applied Systems Analysis AT
• Marine Institute IE
• Tula Foundation CA
• University of Southampton GB
• Auburn University US
• University of Maryland, College Park US
• University of Miami US
• Laboratoire de Météorologie Dynamique FR
• NOAA Atlantic Oceanographic and Meteorological Laboratories US
• Oak Ridge National Laboratory US
• Stanford University US
• Japan Meteorological Agency JP
• ETH Zurich CH
• Institute of Applied Energy JP
• Princeton University US
• University of Bern CH
• Max Planck Institute for Meteorology DE
• National Centre for Earth Observation GB
• Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques FR
• Bermuda Institute of Ocean Sciences BM
• University of Alaska Fairbanks US
• University of Bergen
• University of Washington US
• Goddard Space Flight Center US
• Université Fédérale de Toulouse Midi-Pyrénées FR
• University of Tasmania AU
• Swedish Meteorological and Hydrological Institute SE
• CICERO Center for International Climate Research
• Institute of Arctic and Alpine Research US

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