Timescales for detection of trends in the ocean carbon sink

Abstract

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.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Modelled and observed mean 1982–2011 CO2 flux in 15 ocean biomes.
Figure 2: Forced trends and internal variability of CESM-LE trends in sea-to-air CO2 flux.
Figure 3: Time of emergence for sea-to-air CO2 flux.

References

  1. 1

    Khatiwala, S., Primeau, F. & Hall, T. Reconstruction of the history of anthropogenic CO2 concentrations in the ocean. Nature 462, 346–349 (2009)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Ciais, P. & Sabine, C. in Climate Change. The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds Stocker, T. F. et al.) Ch. 6, 1535 (Cambridge Univ. Press, 2013)

  3. 3

    Gruber, N. et al. Oceanic sources, sinks, and transport of atmospheric CO2. Glob. Biogeochem. Cycles 23, GB1005 (2009)

    Article  Google Scholar 

  4. 4

    Takahashi, T. et al. Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans. Deep Sea Res. Part II 56, 554–577 (2009)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Landschützer, P. et al. The reinvigoration of the Southern Ocean carbon sink. Science 349, 1221–1224 (2015)

    ADS  Article  Google Scholar 

  6. 6

    Schuster, U. et al. An assessment of the Atlantic and Arctic sea–air CO2 fluxes, 1990–2009. Biogeosciences 10, 607–627 (2013)

    ADS  Article  Google Scholar 

  7. 7

    Randerson, J. T. et al. Multicentury changes in ocean and land contributions to the climate-carbon feedback. Glob. Biogeochem. Cycles 29, 744–759 (2015)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Munro, D. R. et al. Recent evidence for a strengthening CO2 sink in the Southern Ocean from carbonate system measurements in the Drake Passage (2002–2015). Geophys. Res. Lett. 42, 7623–7630 (2015)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Bates, N. et al. A time-series view of changing ocean chemistry due to ocean uptake of anthropogenic CO2 and ocean acidification. Oceanography 27, 126–141 (2014)

    Article  Google Scholar 

  10. 10

    Fay, A. R. & McKinley, G. A. Global trends in surface ocean pCO2 from in situ data. Glob. Biogeochem. Cycles 27, 541–557 (2013)

    ADS  CAS  Article  Google Scholar 

  11. 11

    McKinley, G. A., Fay, A. R., Takahashi, T. & Metzl, N. Convergence of atmospheric and North Atlantic carbon dioxide trends on multidecadal timescales. Nature Geosci . 4, 606–610 (2011)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Le Quéré, C., Raupach, M. R., Canadell, J. G. & Al, G. M. E. Trends in the sources and sinks of carbon dioxide. Nature Geosci . 2, 831–836 (2009)

    ADS  Article  Google Scholar 

  13. 13

    Le Quéré, C., Takahashi, T., Buitenhuis, E. T., Rödenbeck, C. & Sutherland, S. C. Impact of climate change and variability on the global oceanic sink of CO2. Glob. Biogeochem. Cycles 24, GB4007 (2010)

    Article  Google Scholar 

  14. 14

    Deser, C., Phillips, A., Bourdette, V. & Teng, H. Uncertainty in climate change projections: the role of internal variability. Clim. Dyn. 38, 527–546 (2012)

    Article  Google Scholar 

  15. 15

    DeVries, T. The oceanic anthropogenic CO2 sink: storage, air-sea fluxes, and transports over the industrial era. Glob. Biogeochem. Cycles 28, 631–647 (2014)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Sarmiento, J. L. & LeQuéré, C. Oceanic carbon dioxide uptake in a model of century-scale global warming. Science 274, 1346–1350 (1996)

    ADS  CAS  Article  Google Scholar 

  17. 17

    Deser, C., Knutti, R., Solomon, S. & Phillips, A. S. Communication of the role of natural variability in future North American climate. Nature Clim. Change 2, 775–779 (2012)

    ADS  Article  Google Scholar 

  18. 18

    Frölicher, T. L., Joos, F., Plattner, G.-K., Steinacher, M. & Doney, S. C. Natural variability and anthropogenic trends in oceanic oxygen in a coupled carbon cycle-climate model ensemble. Glob. Biogeochem. Cycles 23, GB1003 (2009)

    ADS  Article  Google Scholar 

  19. 19

    Ullman, D. J., McKinley, G. A., Bennington, V. & Dutkiewicz, S. Trends in the North Atlantic carbon sink: 1992–2006. Glob. Biogeochem. Cycles 23, GB4011 (2009)

    ADS  Article  Google Scholar 

  20. 20

    Lovenduski, N. & Gruber, N. Toward a mechanistic understanding of the decadal trends in the Southern Ocean carbon sink. Glob. Biogeochem. Cycles 22, GB3016 (2008)

    ADS  Article  Google Scholar 

  21. 21

    Long, M. C., Lindsay, K., Peacock, S., Moore, J. K. & Doney, S. C. Twentieth-century oceanic carbon uptake and storage in CESM1 (BGC). J. Clim. 26, 6775–6800 (2013)

    ADS  Article  Google Scholar 

  22. 22

    Resplandy, L., Séférian, R. & Bopp, L. Natural variability of CO2 and O2 fluxes: what can we learn from centuries-long climate models simulations? J. Geophys. Res. 120, 384–404 (2015)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Frölicher, T. L. et al. Dominance of the Southern Ocean in anthropogenic carbon and heat uptake in CMIP5 models. J. Clim. 28, 862–886 (2015)

    ADS  Article  Google Scholar 

  24. 24

    Hawkins, E. & Sutton, R. The potential to narrow uncertainty in regional climate predictions. Bull. Am. Meteorol. Soc. 90, 1095–1107 (2009)

    ADS  Article  Google Scholar 

  25. 25

    Kay, J. E. et al. The Community Earth System Model (CESM) Large Ensemble Project: a community resource for studying climate change in the presence of internal climate variability. Bull. Am. Meteorol. Soc. 96, 1333–1349 (2014)

    Article  Google Scholar 

  26. 26

    Rodgers, K. B., Lin, J. & Frolicher, T. L. Emergence of multiple ocean ecosystem drivers in a large ensemble suite with an Earth system model. Biogeosciences 12, 3301–3320 (2015)

    ADS  Article  Google Scholar 

  27. 27

    Lovenduski, N. S., Fay, A. R. & McKinley, G. A. Observing multi-decadal trends in Southern Ocean CO2 uptake: what can we learn from an ocean model? Glob. Biogeochem. Cycles 29, 416–426 (2015)

    ADS  CAS  Article  Google Scholar 

  28. 28

    Landschützer, P., Gruber, N., Bakker, D. C. E. & Schuster, U. Recent variability of the global ocean carbon sink. Glob. Biogeochem. Cycles 28, 927–949 (2014)

    ADS  Article  Google Scholar 

  29. 29

    Hawkins, E. & Sutton, R. Time of emergence of climate signals. Geophys. Res. Lett. 39, L01702 (2012)

    ADS  Article  Google Scholar 

  30. 30

    Hurrell, J. W. et al. The community earth system model: a framework for collaborative research. Bull. Am. Meteorol. Soc. 94, 1339–1360 (2013)

    ADS  Article  Google Scholar 

  31. 31

    Moore, J. K. et al. Marine ecosystem dynamics and biogeochemical cycling in the Community Earth System Model [CESM1 (BGC)]: comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 scenarios. J. Clim. 26, 9291–9312 (2013)

    ADS  Article  Google Scholar 

  32. 32

    Danabasoglu, G. S. C. et al. The CCSM4 Ocean Component. J. Clim. 25, 1361–1389 (2012)

    ADS  Article  Google Scholar 

  33. 33

    Bakker, D. C. E. et al. An update to the surface ocean CO2 atlas (SOCAT version 2). Earth Syst. Sci. Data 6, 69–90 (2014)

    ADS  Article  Google Scholar 

  34. 34

    Fay, A. R. & McKinley, G. A. Global open-ocean biomes: mean and temporal variability. Earth Syst. Sci. Data 6, 273–284 (2014)

    Google Scholar 

  35. 35

    Fay, A. R., McKinley, G. A. & Lovenduski, N. S. Southern Ocean carbon trends: sensitivity to methods. Geophys. Res. Lett. 41, 6833–6840 (2014)

    ADS  CAS  Article  Google Scholar 

  36. 36

    Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012)

    ADS  Article  Google Scholar 

  37. 37

    Chylek, P., Li, J., Dubey, M. K., Wang, M. & Lesins, G. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2. Atmos. Chem. Phys. Discuss . 11, 22893–22907 (2011)

    ADS  Article  Google Scholar 

  38. 38

    Collins, W. J. et al. Development and evaluation of an Earth-system model—HadGEM2. Geosci. Model Dev. 4, 1051–1075 (2011)

    ADS  Article  Google Scholar 

  39. 39

    Dufresne, J.-L. et al. Climate change projections using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5. Clim. Dyn. 40, 2123–2165 (2013)

    Article  Google Scholar 

  40. 40

    Dunne, J. P. et al. GFDL’s ESM2 global coupled climate-carbon Earth System Models. Part I: physical formulation and baseline simulation characteristics. J. Clim. 25, 6646–6665 (2012)

    ADS  Article  Google Scholar 

  41. 41

    Fogli, P. G. et al. INGV-CMCC carbon (ICC): a carbon cycle earth system model. CMCC Res. Pap. 61, http://ssrn.com/abstract=1517282 (Social Science Research Network, 2009)

  42. 42

    Giorgetta, M. et al. CMIP5 simulations of the Max Planck Institute for Meteorology (MPI-M) based on the MPI-ESM-LR model: the historical experiment. http://dx.doi.org/10.1594/WDCC/CMIP5.MXELhi (World Data Centre for Climate, Earth System Grid Federation, 2012)

  43. 43

    Giorgetta, M. et al. CMIP5 simulations of the Max Planck Institute for Meteorology (MPI-M) based on the MPI-ESM-LR model: the RCP85 experiment. http://dx.doi.org/10.1594/WDCC/CMIP5.MXELr8 (World Data Centre for Climate, Earth System Grid Federation, 2012)

  44. 44

    Ji, D. et al. Description and basic evaluation of Beijing Normal University Earth System Model (BNU-ESM) version 1. Geosci. Model Dev . 7, 2039–2064 (2014)

    ADS  Article  Google Scholar 

  45. 45

    Lindsay, K. et al. Preindustrial-control and twentieth-century carbon cycle experiments with the Earth System Model CESM1 (BGC). J. Clim. 27, 8981–9005 (2014)

    ADS  Article  Google Scholar 

  46. 46

    Tjiputra, J. F. et al. Evaluation of the carbon cycle components in the Norwegian Earth System Model (NorESM). Geosci. Model Dev . 6, 301–325 (2013)

    ADS  CAS  Article  Google Scholar 

  47. 47

    Volodin, E. M., Dianskii, N. A. & Gusev, A. V. Simulating present-day climate with the INMCM4.0 coupled model of the atmospheric and oceanic general circulations. Izv. Atmos. Ocean. Phys. 46, 414–431 (2010)

    Article  Google Scholar 

  48. 48

    Watanabe, S. et al. MIROC-ESM 2010: model description and basic results of CMIP5-20c3m experiments. Geosci. Model Dev. 4, 845–872 (2011)

    ADS  Article  Google Scholar 

  49. 49

    Wu, T. et al. Global carbon budgets simulated by the Beijing Climate Center Climate System Model for the last century. J. Geophys. Res. 118, 4326–4347 (2013)

    CAS  Google Scholar 

Download references

Acknowledgements

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

Affiliations

Authors

Contributions

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.

Corresponding author

Correspondence to Galen A. McKinley.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Comparison of 1982–2011 mean CO2 flux.

a, Data-based climatology (ref. 28). b, CESM large ensemble 32-member mean. c, Mean of 12 CMIP5 models.

Extended Data Figure 2 Forced trends and variability of CMIP5 trends in sea-to-air CO2 flux.

Forced trends for a, 1990–1999, b, 1990–2019 and c, 1990–2089. Grey areas are where the forced trend cannot be distinguished from the variability with 95% confidence (Methods). CO2 flux trend standard deviations, indicating the impact of variability on CO2 flux trends, for d, 1990–1999, e, 1990–2019 and f, 1990–2089. Negative values indicate increasing ocean carbon uptake.

Extended Data Table 1 Comparison of observed and modelled and CO2 flux variability for 1982–2011
Extended Data Table 2 Comparison of observed and modelled and CO2 flux trends for 1982–2011
Extended Data Table 3 CMIP5 models used in this work
Extended Data Table 4 Biome long names and mean time of emergence

PowerPoint slides

Source data

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

McKinley, G., Pilcher, D., Fay, A. et al. Timescales for detection of trends in the ocean carbon sink. Nature 530, 469–472 (2016). https://doi.org/10.1038/nature16958

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing