Letter | Published:

Implications for climate sensitivity from the response to individual forcings

Nature Climate Change volume 6, pages 386389 (2016) | Download Citation


Climate sensitivity to doubled CO2 is a widely used metric for the large-scale response to external forcing. Climate models predict a wide range for two commonly used definitions: the transient climate response (TCR: the warming after 70 years of CO2 concentrations that rise at 1% per year), and the equilibrium climate sensitivity (ECS: the equilibrium temperature change following a doubling of CO2 concentrations). Many observational data sets have been used to constrain these values, including temperature trends over the recent past1,2,3,4,5,6, inferences from palaeoclimate7,8 and process-based constraints from the modern satellite era9,10. However, as the IPCC recently reported11, different classes of observational constraints produce somewhat incongruent ranges. Here we show that climate sensitivity estimates derived from recent observations must account for the efficacy of each forcing active during the historical period. When we use single-forcing experiments to estimate these efficacies and calculate climate sensitivity from the observed twentieth-century warming, our estimates of both TCR and ECS are revised upwards compared to previous studies, improving the consistency with independent constraints.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from $8.99

All prices are NET prices.

Change history

  • Corrected online 10 March 2016

    In the version of this Letter originally published online, there was an error in the definition of F2×CO2 in equation (2). The historical instantaneous radiative forcing time series was also updated to reflect land use change, which was inadvertently excluded from the forcing originally calculated from ref. 22. This has resulted in minor changes to data in Figs 1 and 2, as well as in the corresponding main text and Supplementary Information. In addition, the end of the paragraph beginning' Scaling ΔF for each of the single-forcing runs...' should have read '...the CO2-only runs' (not 'GHG-only runs'). The conclusions of the Letter are not affected by these changes. All errors have been corrected in all versions of the Letter. The authors thank Nic Lewis for his careful reading of the original manuscript that resulted in the identification of these errors.


  1. 1.

    , , , & Quantifying uncertainties in climate system properties with the use of recent climate observations. Science 295, 113–117 (2002).

  2. 2.

    , & Estimated PDFs of climate system properties including natural and anthropogenic forcings. Geophys. Res. Lett. 33, L01705 (2006).

  3. 3.

    & The implications for climate sensitivity of AR5 forcing and heat uptake estimates. Clim. Dynam. 45, 1009–1023 (2014).

  4. 4.

    et al. Energy budget constraints on climate response. Nature Geosci. 6, 415–416 (2013).

  5. 5.

    , , & Causes of the global warming observed since the 19th century. Atmos. Clim. Sci. 02, 401–415 (2012).

  6. 6.

    et al. Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperatures and global ocean heat content. Environmetrics 23, 253–271 (2012).

  7. 7.

    Making sense of palaeoclimate sensitivity. Nature 491, 683–691 (2012).

  8. 8.

    , , & Can the Last Glacial Maximum constrain climate sensitivity? Geophys. Res. Lett. 39, L24702 (2012).

  9. 9.

    , & Spread in model climate sensitivity traced to atmospheric convective mixing. Nature 505, 37–42 (2014).

  10. 10.

    & A less cloudy future: the role of subtropical subsidence in climate sensitivity. Science 338, 792–794 (2012).

  11. 11.

    et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 1029–1136 (IPCC, Cambridge Univ. Press, 2013).

  12. 12.

    et al. in Climate Processes and Climate Sensitivity Vol. 29 (eds Hansen, J. E. & Takahashi, T.) 130–163 (American Geophysical Union, 1984).

  13. 13.

    et al. Efficacy of climate forcings. J. Geophys. Res. 110, D18104 (2005).

  14. 14.

    , & Why radiative forcing might fail as a predictor of climate change. Clim. Dynam. 24, 497–510 (2005).

  15. 15.

    et al. What caused Earth’s temperature variations during the last 800,000 years? Data-based evidence on radiative forcing and constraints on climate sensitivity. Quat. Sci. Rev. 29, 129–145 (2010).

  16. 16.

    et al. Climate sensitivity estimated from temperature reconstructions of the Last Glacial Maximum. Science 334, 1385–1388 (2011).

  17. 17.

    , , , & The dependence of transient climate sensitivity and radiative feedbacks on the spatial pattern of ocean heat uptake. Geophys. Res. Lett. 41, 1071–1078 (2014).

  18. 18.

    , & Importance of ocean heat uptake efficacy to transient climate change. J. Clim. 23, 2333–2344 (2010).

  19. 19.

    , & Time-varying climate sensitivity from regional feedbacks. J. Clim. 26, 4518–4534 (2013).

  20. 20.

    & The impact of forcing efficacy on the equilibrium climate sensitivity. Geophys. Res. Lett. 41, 3565–3568 (2014).

  21. 21.

    Inhomogeneous forcing and transient climate sensitivity. Nature Clim. Change 4, 274–277 (2014).

  22. 22.

    et al. CMIP5 historical simulations (1850–2012) with GISS ModelE2. J. Adv. Model. Earth Syst. 6, 441–477 (2014).

  23. 23.

    et al. Future climate change under rcp emission scenarios with GISS ModelE2. J. Adv. Model. Earth Syst. 7, 244–267 (2015).

  24. 24.

    et al. Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive. J. Adv. Model. Earth Syst. 6, 141–184 (2014).

  25. 25.

    et al. A new method for diagnosing radiative forcing and climate sensitivity. Geophys. Res. Lett. 31, L03205 (2004).

  26. 26.

    et al. Forcings and chaos in interannual to decadal climate change. J. Geophys. Res. 102, 25679–25720 (1997).

  27. 27.

    , & The inconstancy of the transient climate response parameter under increasing CO2. Phil. Trans. R. Soc. A 373, 20140417 (2015).

  28. 28.

    & Climate response to regional radiative forcing during the twentieth century. Nature Geosci. 2, 294–300 (2009).

  29. 29.

    , , , & Robust bayesian uncertainty analysis of climate system properties using Markov Chain Monte Carlo methods. J. Clim. 20, 1239–1254 (2007).

  30. 30.

    , , , & Constraining transient climate sensitivity using coupled climate model simulations of volcanic eruptions. J. Clim. 27, 7781–7795 (2014).

Download references


Climate modelling at GISS is supported by the NASA Modeling, Analysis and Prediction Program and resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. The authors thank D. McNeall and E. Hawkins for advice on figures, and E. Hawkins, J. Gregory, M. Webb, K. Taylor and R. Pincus for helpful discussions.

Author information


  1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA

    • Kate Marvel
    •  & Ron L. Miller
  2. NASA Goddard Institute for Space Studies, New York, New York 10025, USA

    • Kate Marvel
    • , Gavin A. Schmidt
    • , Ron L. Miller
    •  & Larissa S. Nazarenko
  3. Center for Climate Systems Research, Columbia University, New York, New York 10025, USA

    • Larissa S. Nazarenko


  1. Search for Kate Marvel in:

  2. Search for Gavin A. Schmidt in:

  3. Search for Ron L. Miller in:

  4. Search for Larissa S. Nazarenko in:


K.M. and G.A.S. designed the research and wrote the paper, with input from R.L.M. R.L.M. and L.S.N. provided the forcing data. L.S.N. ran the climate model experiments. All authors contributed to the interpretation of the results.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Kate Marvel or Gavin A. Schmidt or Ron L. Miller.

Supplementary information

About this article

Publication history