Letter | Published:

Timescales for detection of trends in the ocean carbon sink

Nature volume 530, pages 469472 (25 February 2016) | Download Citation


The ocean has absorbed 41 per cent of all anthropogenic carbon emitted as a result of fossil fuel burning and cement manufacture1,2. The magnitude and the large-scale distribution of the ocean carbon sink is well quantified for recent decades3,4. In contrast, temporal changes in the oceanic carbon sink remain poorly understood5,6,7. It has proved difficult to distinguish between air-to-sea carbon flux trends that are due to anthropogenic climate change and those due to internal climate variability5,6,8,9,10,11,12,13. Here we use a modelling approach that allows for this separation14, revealing how the ocean carbon sink may be expected to change throughout this century in different oceanic regions. Our findings suggest that, owing to large internal climate variability, it is unlikely that changes in the rate of anthropogenic carbon uptake can be directly observed in most oceanic regions at present, but that this may become possible between 2020 and 2050 in some regions.

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The National Science Foundation sponsors National Center for Atmospheric Research, where the Community Earth System Model is developed. Computing resources were provided by the Climate Simulation Laboratory at NCAR’s Computational and Information Systems Laboratory, sponsored by the NSF and other agencies. NCAR’s Advanced Study Program sponsored D.J.P., K.L., M.C.L. and G.A.M. to initiate this analysis. We also thank NASA for funding (grants NNX11AF53G and NNX13AC53G to G.A.M., D.J.P., A.R.F. and N.S.L.). N.S.L. also thanks the NSF (grant OCE-1155240) and NOAA (grant NA12OAR4310058).

Author information


  1. Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, Madison, Wisconsin, USA

    • Galen A. McKinley
    • , Darren J. Pilcher
    •  & Amanda R. Fay
  2. Center for Climatic Research, University of Wisconsin—Madison, Madison, Wisconsin, USA

    • Galen A. McKinley
    •  & Darren J. Pilcher
  3. Space Science and Engineering Center, University of Wisconsin—Madison, Madison, Wisconsin, USA

    • Galen A. McKinley
    •  & Amanda R. Fay
  4. NOAA Pacific Marine Environmental Laboratory, Seattle, Washington, USA

    • Darren J. Pilcher
  5. National Center for Atmospheric Research, Boulder, Colorado, USA

    • Keith Lindsay
    •  & Matthew C. Long
  6. Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA

    • Nicole S. Lovenduski


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G.A.M. conceived the analysis, which was further refined by all authors. K.L. coordinated inclusion of ocean biogeochemistry in CESM-LE. D.J.P. and A.R.F. did the analysis. All authors discussed results and contributed to writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Galen A. McKinley.

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