Articles | Volume 5, issue 1
Earth Syst. Sci. Data, 5, 165–185, 2013
Earth Syst. Sci. Data, 5, 165–185, 2013
08 May 2013
08 May 2013

The global carbon budget 1959–2011

C. Le Quéré1, R. J. Andres2, T. Boden2, T. Conway3, R. A. Houghton4, J. I. House5, G. Marland6, G. P. Peters7, G. R. van der Werf8, A. Ahlström9, R. M. Andrew7, L. Bopp10, J. G. Canadell11, P. Ciais10, S. C. Doney12, C. Enright1, P. Friedlingstein13, C. Huntingford14, A. K. Jain15, C. Jourdain1,*, E. Kato16, R. F. Keeling17, K. Klein Goldewijk19,20,18, S. Levis21, P. Levy14, M. Lomas22, B. Poulter10, M. R. Raupach11, J. Schwinger24,23, S. Sitch25, B. D. Stocker26,27, N. Viovy10, S. Zaehle28, and N. Zeng29 C. Le Quéré et al.
  • 1Tyndall Centre for Climate Change Research, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
  • 2Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
  • 3National Oceanic & Atmosphere Administration, Earth System Research Laboratory (NOAA/ESRL), Boulder, Colorado 80305, USA
  • 4Woods Hole Research Centre (WHRC), Falmouth, Massachusetts 02540, USA
  • 5Cabot Institute, Dept. of Geography, University of Bristol, Bristol, UK
  • 6Research Institute for Environment, Energy, and Economics, Appalachian State University, Boone, North Carolina 28608, USA
  • 7Center for International Climate and Environmental Research – Oslo (CICERO), Oslo, Norway
  • 8Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, the Netherlands
  • 9Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
  • 10Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, CE Orme des Merisiers, 91191 Gif sur Yvette Cedex, France
  • 11Global Carbon Project, CSIRO Marine and Atmospheric Research, Canberra, Australia
  • 12Woods Hole Oceanographic Institution (WHOI), Woods Hole, Massachusetts 02543, USA
  • 13College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
  • 14Centre for Ecology and Hydrology (CEH), Wallingford, OX10 8BB, UK
  • 15Department of Atmospheric Sciences, University of Illinois, Illinois, USA
  • 16Center for Global Environmental Research (CGER), National Institute for Environmental Studies (NIES), Tsukuba, Japan
  • 17University of California, San Diego, Scripps Institution of Oceanography, La Jolla, California 92093-0244, USA
  • 18PBL Netherlands Environmental Assessment Agency, The Hague/Bilthoven, the Netherlands
  • 19Department Innovation and Environmental Sciences (IMEW) Utrecht University, Utrecht, the Netherlands
  • 20Institute for History and Culture (OGC), Utrecht University, Utrecht, the Netherlands
  • 21National Center for Atmospheric Research (NCAR), Boulder, Colorado, USA
  • 22Centre for Terrestrial Carbon Dynamics (CTCD), Sheffield University, UK
  • 23Geophysical Institute, University of Bergen, Bergen, Norway
  • 24Bjerknes Centre for Climate Research, Bergen, Norway
  • 25College of Life and Environmental Sciences, University of Exeter, EX4 4RJ, Exeter, UK
  • 26Climate and Environmental Physics, Physics Institute, University of Bern, 3012 Bern, Switzerland
  • 27Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
  • 28Max-Planck-Institut für Biogeochemie, P.O. Box 600164, Hans-Knöll-Str. 10, 07745 Jena, Germany
  • 29Department of Atmospheric and Oceanic Science, University of Maryland, Maryland, USA
  • *now at: Food and Agriculture Organization of the United Nations (FAO), Rome, Italy

Abstract. Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002–2011), EFF was 8.3 ± 0.4 PgC yr−1, ELUC 1.0 ± 0.5 PgC yr−1, GATM 4.3 ± 0.1 PgC yr−1, SOCEAN 2.5 ± 0.5 PgC yr−1, and SLAND 2.6 ± 0.8 PgC yr−1. For year 2011 alone, EFF was 9.5 ± 0.5 PgC yr−1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 ± 0.5 PgC yr−1, approximately constant throughout the decade; GATM was 3.6 ± 0.2 PgC yr−1, SOCEAN was 2.7 ± 0.5 PgC yr−1, and SLAND was 4.1 ± 0.9 PgC yr−1. GATM was low in 2011 compared to the 2002–2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 ± 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9–3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future.

All data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_V2013).

Global carbon budget 2013