[go: up one dir, main page]
Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Reconstruction of the history of anthropogenic CO2 concentrations in the ocean

Nature volume 462, pages 346–349 (2009)Cite this article

Abstract

The release of fossil fuel CO2 to the atmosphere by human activity has been implicated as the predominant cause of recent global climate change1. The ocean plays a crucial role in mitigating the effects of this perturbation to the climate system, sequestering 20 to 35 per cent of anthropogenic CO2 emissions2,3,4. Although much progress has been made in recent years in understanding and quantifying this sink, considerable uncertainties remain as to the distribution of anthropogenic CO2 in the ocean, its rate of uptake over the industrial era, and the relative roles of the ocean and terrestrial biosphere in anthropogenic CO2 sequestration. Here we address these questions by presenting an observationally based reconstruction of the spatially resolved, time-dependent history of anthropogenic carbon in the ocean over the industrial era. Our approach is based on the recognition that the transport of tracers in the ocean can be described by a Green’s function, which we estimate from tracer data using a maximum entropy deconvolution technique. Our results indicate that ocean uptake of anthropogenic CO2 has increased sharply since the 1950s, with a small decline in the rate of increase in the last few decades. We estimate the inventory and uptake rate of anthropogenic CO2 in 2008 at 140 ± 25 Pg C and 2.3 ± 0.6 Pg C yr-1, respectively. We find that the Southern Ocean is the primary conduit by which this CO2 enters the ocean (contributing over 40 per cent of the anthropogenic CO2 inventory in the ocean in 2008). Our results also suggest that the terrestrial biosphere was a source of CO2 until the 1940s, subsequently turning into a sink. Taken over the entire industrial period, and accounting for uncertainties, we estimate that the terrestrial biosphere has been anywhere from neutral to a net source of CO2, contributing up to half as much CO2 as has been taken up by the ocean over the same period.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Anthropogenic carbon in the ocean.
Figure 2: Anthropogenic carbon uptake rate from 1765 to 2008 (black solid line).
Figure 3: Evolution of anthropogenic CO 2 sources and sinks between 1765 and 2005.

Similar content being viewed by others

References

  1. Solomon, S. et al., eds. Climate Change 2007 — The Physical Science Basis (Cambridge Univ. Press, 2007)

    Google Scholar 

  2. Sabine, C. L. et al. The ocean sink for anthropogenic CO2 . Science 305, 367–371 (2004)

    CAS  Google Scholar 

  3. Houghton, R. A. Balancing the global carbon budget. Annu. Rev. Earth Planet. Sci. 35, 313–347 (2007)

    CAS  Google Scholar 

  4. Denman, K. L. et al. in Climate Change 2007 — The Physical Science Basis (eds Solomon, S. et al.) 499–587 (Cambridge Univ. Press, 2007)

    Google Scholar 

  5. Brewer, P. G. Direct measurements of the oceanic CO2 increase. Geophys. Res. Lett. 5, 997–1000 (1978)

    CAS  Google Scholar 

  6. Chen, C.-T. & Millero, F. J. Gradual increase of oceanic CO2 . Nature 277, 205–206 (1979)

    CAS  Google Scholar 

  7. Key, R. M. et al. A global ocean carbon climatology: results from GLODAP. Glob. Biogeochem. Cycles 18 10.1029/2004GB002247 (2004)

  8. Gruber, N., Sarmiento, J. L. & Stocker, T. F. An improved method for detecting anthropogenic CO2 in the oceans. Glob. Biogeochem. Cycles 10, 809–837 (1996)

    CAS  Google Scholar 

  9. Wallace, D. W. R. Ocean measurements and models of carbon sources and sinks. Glob. Biogeochem. Cycles 15 3–10 10.1029/2000GB001354 (2001)

    CAS  Google Scholar 

  10. Matsumoto, K. & Gruber, N. How accurate is the estimation of anthropogenic carbon in the ocean? An evaluation of the ΔC* method. Glob. Biogeochem. Cycles 19 10.1029/2004GB002397 (2005)

  11. Waugh, D. W., Hall, T. M., McNeil, B. I., Key, R. M. & Matear, R. J. Anthropogenic CO2 in the oceans estimated using transit-time distributions. Tellus B 58, 376–390 (2006)

    Google Scholar 

  12. Hall, T. M., Haine, T. W. N. & Waugh, D. W. Inferring the concentration of anthropogenic carbon in the ocean from tracers. Glob. Biogeochem. Cycles 16 10.1029/2001GB001835 (2002)

  13. Sarmiento, J. L., Orr, J. C. & Siegenthaler, U. A perturbation simulation of CO2 uptake in an ocean general circulation model. J. Geophys. Res. 97, 3621–3645 (1992)

    CAS  Google Scholar 

  14. Tarantola, A. Inverse Problem Theory and Methods for Model Parameter Estimation (Society for Industrial and Applied Mathematics, 2005)

    Google Scholar 

  15. Tanhua, T. et al. Ventilation of the Arctic Ocean: mean ages and inventories of anthropogenic CO2 and CFC-11. J. Geophys. Res. 114 10.1029/2008JC004868 (2009)

  16. Houghton, R. A. Carbon Flux to the Atmosphere from Land-Use Changes 1850-2005 (Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2008) 〈http://cdiac.ornl.gov/trends/landuse/houghton/1850-2005.txt〉

    Google Scholar 

  17. Canadell, J. G. et al. Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity and efficiency of natural sinks. Proc. Natl Acad. Sci. USA 104, 18866–18870 (2007)

    CAS  Google Scholar 

  18. Joos, F., Meyer, R., Bruno, M. & Leuenberger, M. The variability in the carbon sinks as reconstructed for the last 1000 years. Geophys. Res. Lett. 26, 1437–1440 (1999)

    CAS  Google Scholar 

  19. Le Quéré, C. et al. Saturation of the Southern Ocean CO2 sink due to recent climate change. Science 316 10.1126/science.1136188 (2007)

  20. Lovenduski, N. S., Gruber, N., Doney, S. C. & Lima, I. D. Enhanced CO2 outgassing in the Southern Ocean from a positive phase of the Southern Annular Mode. Glob. Biogeochem. Cycles 21 10.1029/2006GB002900 (2007)

  21. Böning, C. W., Dispert, A., Visbeck, M., Rintoul, S. & Schwarzkopf, F. U. Response of the Antarctic Circumpolar Current to recent climate change. Nature Geosci. 1, 864–869 (2008)

    Google Scholar 

  22. Zickfeld, K., Fyfe, J., Saenko, O. A., Eby, M. & Weaver, A. J. Response of the global carbon cycle to human-induced changes in the Southern Hemisphere winds. Geophys. Res. Lett. 34 10.1029/2006GL028797 (2007)

  23. Mikaloff Fletcher, S. E. et al. Inverse estimates of anthropogenic CO2 uptake, transport, and storage by the ocean. Glob. Biogeochem. Cycles 20 10.1029/2005GB002530 (2006)

  24. Matsumoto, K. et al. Evaluation of ocean carbon cycle models with data-based metrics. Geophys. Res. Lett. 31 10.1029/2003GL018970 (2004)

  25. Cao, L. et al. The role of ocean transport in the uptake of anthropogenic CO2 . Biogeosciences 6, 375–390 (2009)

    CAS  Google Scholar 

  26. Waugh, D. W., Haine, T. W. & Hall, T. M. Transport times and anthropogenic carbon in the subpolar North Atlantic Ocean. Deep Sea Res. I 51, 1475–1491 (2004)

    CAS  Google Scholar 

  27. Khatiwala, S., Visbeck, M. & Schlosser, P. Age tracers in an ocean GCM. Deep Sea Res. I 48, 1423–1441 (2001)

    CAS  Google Scholar 

  28. Hall, T. M., Waugh, D. W., Haine, T. W. N., Robbins, P. E. & Khatiwala, S. Estimates of anthropogenic carbon in the Indian Ocean with allowance for mixing and time-varying air-sea CO2 disequilibrium. Glob. Biogeochem. Cycles 18 10.1029/2003GB002120 (2004)

  29. Atmospheric Trace Gases: Carbon Dioxide. (Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2009) 〈http://cdiac.ornl.gov/trends/co2〉

  30. Boden, T. A., Marland, G. & Andres, R. J. Global, Regional, and National Fossil-fuel CO2 Emissions 10.3334/CDIAC/00001 (Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, 2009); 〈http://cdiac.ornl.gov/trends/emis/tre_glob.html〉.

  31. Locarnini, R. A. et al. World Ocean Atlas 2005 Vol. 1, Temperature (NOAA Atlas NESDIS 61, US Government Printing Office, 2006)

    Google Scholar 

  32. Antonov, J. I., Locarnini, R. A., Boyer, T. P., Mishonov, A. V. & Garcia, H. E. World Ocean Atlas 2005 Vol. 2, Salinity (NOAA Atlas NESDIS 62, US Government Printing Office, 2006)

    Google Scholar 

  33. Garcia, H. E., Locarnini, R. A., Boyer, T. P. & Antonov, J. I. World Ocean Atlas 2005 Vol. 3, Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation (NOAA Atlas NESDIS 63, US Government Printing Office, 2006)

    Google Scholar 

  34. Garcia, H. E., Locarnini, R. A., Boyer, T. P. & Antonov, J. I. World Ocean Atlas 2005 Vol. 4, Nutrients (Phosphate, Nitrate, Silicate) (NOAA Atlas NESDIS 64, US Government Printing Office, 2006)

    Google Scholar 

  35. Broecker, W. S. et al. How much deep water is formed in the Southern Ocean? J. Geophys. Res. 103, 15833–15844 (1998)

    CAS  Google Scholar 

  36. Walker, S. J., Weiss, R. F. & Salameh, P. K. Reconstructed histories of the annual mean atmospheric mole fractions for the halocarbons CFC11, CFC-12, CFC113 and carbon tetrachloride. J. Geophys. Res. 105, 14285–14296 (2000)

    CAS  Google Scholar 

  37. Smethie, W. M. & Fine, R. A. Rates of North Atlantic Deep Water formation calculated from chlorofluorocarbon inventories. Deep Sea Res. I 48, 189–215 (2001)

    CAS  Google Scholar 

  38. Rhein, M. et al. Labrador Sea Water: pathways, CFC inventory, and formation rates. J. Phys. Oceanogr. 32, 648–665 (2002)

    Google Scholar 

  39. Lo Monaco, C., Goyet, C., Metzl, N., Poisson, A. & Touratier, F. Distribution and inventory of anthropogenic CO2 in the Southern Ocean: comparison of three data-based methods. J. Geophys. Res. 110 10.1029/2004JC002571 (2005)

  40. Sweeney, C. et al. Constraining global air-sea gas exchange for CO2 with recent bomb 14C measurements. Glob. Biogeochem. Cycles 21 10.1029/2006GB002784 (2007)

  41. 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. II 56 10.1016/j.dsr2.2008.12.009 (2009)

Download references

Acknowledgements

This work was supported by US NSF grants OCE 06-23366 (to S.K. and T.H.) and OCE 07-26871 (to F.P.).

Author Contributions All authors contributed extensively to the work presented in this paper.

Author information

Authors and Affiliations

  1. Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA ,

    S. Khatiwala

  2. Department of Earth System Science, University of California, Irvine, California 92697, USA,

    F. Primeau

  3. NASA Goddard Institute for Space Studies, 2880 Broadway, New York, New York 10025, USA ,

    T. Hall

Authors
  1. S. Khatiwala
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. F. Primeau
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. T. Hall
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to S. Khatiwala.

Supplementary information

Supplementary Information

This file contains Supplementary Methods, Supplementary Figures S1-S3 with Legends and Supplementary References. (PDF 351 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Khatiwala, S., Primeau, F. & Hall, T. Reconstruction of the history of anthropogenic CO2 concentrations in the ocean. Nature 462, 346–349 (2009). https://doi.org/10.1038/nature08526

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature08526

Search

Advanced search

Quick links

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