Skip to main content

Thank you for visiting 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:

Human-induced global ocean warming on multidecadal timescales


Large-scale increases in upper-ocean temperatures are evident in observational records1. Several studies have used well-established detection and attribution methods to demonstrate that the observed basin-scale temperature changes are consistent with model responses to anthropogenic forcing and inconsistent with model-based estimates of natural variability2,3,4,5. These studies relied on a single observational data set and employed results from only one or two models. Recent identification of systematic instrumental biases6 in expendable bathythermograph data has led to improved estimates of ocean temperature variability and trends7,8,9 and provide motivation to revisit earlier detection and attribution studies. We examine the causes of ocean warming using these improved observational estimates, together with results from a large multimodel archive of externally forced and unforced simulations. The time evolution of upper ocean temperature changes in the newer observational estimates is similar to that of the multimodel average of simulations that include the effects of volcanic eruptions. Our detection and attribution analysis systematically examines the sensitivity of results to a variety of model and data-processing choices. When global mean changes are included, we consistently obtain a positive identification (at the 1% significance level) of an anthropogenic fingerprint in observed upper-ocean temperature changes, thereby substantially strengthening existing detection and attribution evidence.

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

Access options

Buy this article

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

Figure 1: Global mean ΔT (0–700 m) with respect to a 1957–1990 climatology.
Figure 2: Observed and simulated least-squares linear trends in ΔT over 1960–1999.
Figure 3: Observed and simulated variability metrics S5 and S10, which provide information on the combined spatiotemporal variability of five- and ten-year ΔT trends, respectively.
Figure 4: EOF analysis of basin-average upper-ocean temperature changes.
Figure 5: S/N analysis of basin-scale changes in ΔT.

Similar content being viewed by others


  1. Levitus, S., Antonov, J., Boyer, T. & Stephens, C. Warming of the world ocean. Science 287, 2225–2229 (2000).

    Article  CAS  Google Scholar 

  2. Barnett, T., Pierce, D. & Schnur, R. Detection of anthropogenic climate change in the world’s oceans. Science 292, 270–274 (2001).

    Article  CAS  Google Scholar 

  3. Barnett, T. et al. Penetration of human-induced warming into the world’s oceans. Science 309, 284–287 (2005).

    Article  CAS  Google Scholar 

  4. Pierce, D. W. et al. Anthropogenic warming of the oceans: Observations and model results. J. Clim. 19, 1873–1900 (2006).

    Article  Google Scholar 

  5. Palmer, M., Good, S., Haines, K., Rayner, N. & Stott, P. A new perspective on warming of the global oceans. Geophys. Res. Lett. 36, L20709 (2009).

    Article  Google Scholar 

  6. Gouretski, V. & Koltermann, K. How much is the ocean really warming? Geophys. Res. Lett. 34, L01610 (2007).

    Article  Google Scholar 

  7. Domingues, C. et al. Improved estimates of upper-ocean warming and multi-decadal sea-level rise. Nature 453, 1091–1094 (2008).

    Article  Google Scholar 

  8. Ishii, M. & Kimoto, M. Reevaluation of historical ocean heat content variations with time-varying XBT and MBT depth bias corrections. J. Oceanogr. 65, 287–299 (2009).

    Article  Google Scholar 

  9. Levitus, S. et al. Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems. Geophys. Res. Lett. 36, L07608 (2009).

    Google Scholar 

  10. Ishii, M., Kimoto, M., Sakamoto, K. & Iwasaki, S. Steric sea level changes estimated from historical ocean subsurface temperature and salinity analyses. J. Oceanogr. 62, 155–170 (2006).

    Article  Google Scholar 

  11. Levitus, S., Antonov, J. & Boyer, T. Warming of the world ocean, 1955–2003. Geophys. Res. Lett. 32, L02604 (2005).

    Google Scholar 

  12. Lyman, J. et al. Robust warming of the global upper ocean. Nature 465, 334–337 (2010).

    Article  CAS  Google Scholar 

  13. Gregory, J., Banks, H., Stott, P., Lowe, J. & Palmer, M. Simulated and observed decadal variability in ocean heat content. Geophys. Res. Lett. 31, L15312 (2004).

    Article  Google Scholar 

  14. AchutaRao, K. et al. Variability of ocean heat uptake: Reconciling observations and models. J. Geophys. Res. 111, C05019 (2006).

    Article  Google Scholar 

  15. AchutaRao, K. M. et al. Simulated and observed variability in ocean temperature and heat content. Proc. Natl Acad. Sci. USA 104, 10768–10773 (2007).

    Article  CAS  Google Scholar 

  16. Gleckler, P. et al. Krakatoa’s signature persists in the ocean. Nature 439, 675 (2006).

    Article  CAS  Google Scholar 

  17. IPCC Special Report on Emissions Scenarios (eds Nakicenovic, N. & Swart, R.) (Cambridge Univ. Press, 2000).

  18. Arblaster, J., Meehl, G. & Karoly, D. Future climate change in the Southern Hemisphere: Competing effects of ozone and greenhouse gases. Geophys. Res. Lett. 38, L02701 (2011).

    Article  Google Scholar 

  19. Church, J., White, N. & Arblaster, J. Significant decadal-scale impact of volcanic eruptions on sea level and ocean heat content. Nature 438, 74–77 (2005).

    Article  CAS  Google Scholar 

  20. Gregory, J. Long-term effect of volcanic forcing on ocean heat content. Geophys. Res. Lett. 37, L22701 (2010).

    Article  Google Scholar 

  21. Santer, B. D. et al. Separating signal and noise in atmospheric temperature changes: The importance of timescale. J. Geophys. Res. 116, D22105 (2011).

    Article  Google Scholar 

  22. Hasselmann, K. in Meteorology of Tropical Oceans (ed. Shawn, D. B.) 251–259 (Roy. Met. Soc., 1979).

    Google Scholar 

  23. Santer, B. et al. Identification of human-induced changes in atmospheric moisture content. Proc. Natl Acad. Sci. USA 104, 15248–15253 (2007).

    Article  CAS  Google Scholar 

  24. Gleckler, P. et al. Krakatoa lives: The effect of volcanic eruptions on ocean heat content and thermal expansion. Geophys. Res. Lett. 33, L17702 (2006).

    Article  Google Scholar 

  25. Gregory, J. et al. Comparison of results from several AOGCMs for global and regional sea-level change 1900-2100. Clim. Dynam. 18, 225–240 (2001).

    Article  Google Scholar 

  26. Gregory, J. M., Lowe, J. A. & Tett, S. F. B. Simulated global-mean sea level changes over the last half-millennium. J. Clim. 19, 4576–4591 (2006).

    Article  Google Scholar 

Download references


We acknowledge the climate model development groups for providing their simulation output for analysis, PCMDI for collecting and archiving this data and the World Climate Research Programme’s Working Group on Coupled Modelling for organizing the model data analysis activity. The CMIP3 multimodel data set is supported by the Office of Science, US Department of Energy. Work at Lawrence Livermore National Laboratory (by P.J.G., P.M.C., B.D.S. and K.E.T.) was carried out under the auspices of the US Department of Energy under contract DE-AC52-07NA27344. C.M.D. was partly financially supported by a CSIRO Office of the Chief Executive Postdoctoral Fellowship, the Australian Climate Change Science Program and the Australian Academy of Science (Scientific Visit to North America Program). D.W.P. was partially funded by the US Department of Energy's International ad hoc Detection and Attribution Group (IDAG).

Author information

Authors and Affiliations



P.J.G., B.D.S., D.W.P., T.P.Barnett and K.E.T. designed the research. C.M.D., T.P.Boyer and M.I. contributed new analytic tools. P.J.G., B.D.S., C.M.D., J.A.C., T.P.Boyer, P.M.C. and K.M.A. analysed the data. P.J.G., B.D.S., C.M.D., J.A.C., D.W.P. and K.E.T. wrote the paper.

Corresponding author

Correspondence to P. J. Gleckler.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gleckler, P., Santer, B., Domingues, C. et al. Human-induced global ocean warming on multidecadal timescales. Nature Clim Change 2, 524–529 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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