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.

Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks

Abstract

Global energy budget constraints1,2,3 suggest an equilibrium climate sensitivity around 2 °C, which is lower than estimates from palaeoclimate reconstructions4, process-based observational analyses5,6,7, and global climate model simulations8,9. A key assumption is that the climate sensitivity inferred today also applies to the distant future. Yet, global climate models robustly show that feedbacks vary over time, with a strong tendency for climate sensitivity to increase as equilibrium is approached9,10,11,12,13,14,15,16,17,18. Here I consider the implications of inconstant climate feedbacks for energy budget constraints on climate sensitivity. I find that the long-term value of climate sensitivity is, on average, 26% above that inferred during transient warming within global climate models, with a larger discrepancy when climate sensitivity is high. Moreover, model values of climate sensitivity inferred during transient warming are found to be consistent with energy budget observations1,2,3, indicating that the models are not overly sensitive. Using model-based estimates of how climate feedbacks will change in the future, in conjunction with recent energy budget constraints1,19, produces a current best estimate of equilibrium climate sensitivity of 2.9 °C (1.7–7.1 °C, 90% confidence). These findings suggest that climate sensitivity estimated from global energy budget constraints is in agreement with values derived from other methods and simulated by global climate models.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Inconstancy of feedbacks in CMIP5 abrupt CO2 quadrupling and 1% yr−1 CO2 ramping simulations.
Figure 2: Relationship between ECS and ECSinfer for CMIP5 models, and comparison with energy budget constraints from ref. 1 (top) and refs 1,19 (bottom).
Figure 3: Probability density functions of ECSinfer and ECS derived from energy budget constraints from ref. 1 and refs 1,19, and comparison with CMIP5 models.

Similar content being viewed by others

References

  1. Otto, A. et al. Energy budget constraints on climate response. Nat. Geosci. 6, 415–416 (2013).

    Article  CAS  Google Scholar 

  2. Lewis, N. & Curry, J. A. The implications for climate sensitivity of AR5 forcing and heat uptake estimates. Clim. Dynam. 45, 1009–1023 (2015).

    Article  Google Scholar 

  3. Kummer, J. R. & Dessler, A. E. The impact of forcing efficacy on the equilibrium climate sensitivity. Geophys. Res. Lett. 41, 3565–3568 (2014).

    Article  Google Scholar 

  4. Royer, D. L. Climate sensitivity in the geologic past. Annu. Rev. Earth Planet. Sci. 44, 277–293 (2016).

    Article  CAS  Google Scholar 

  5. Fasullo, J. T. & Trenberth, K. E. A less cloudy future: the role of subtropical subsidence in climate sensitivity. Science 338, 792–794 (2012).

    Article  CAS  Google Scholar 

  6. Sherwood, S. C., Bony, S. & Dufresne, J.-L. Spread in model climate sensitivity traced to atmospheric convective mixing. Nature 505, 37–42 (2014).

    Article  Google Scholar 

  7. Tan, I., Storelvmo, T. & Zelinka, M. D. Observational constraints on mixed-phase clouds imply higher climate sensitivity. Science 352, 224–227 (2016).

    Article  CAS  Google Scholar 

  8. Forster, P. M. et al. Evaluating adjusted forcing and model spread for historical and future scenarios in the CMIP5 generation of climate models. J. Geophys. Res. Atmos. 118, 1139–1150 (2013).

    Article  Google Scholar 

  9. Geoffroy, O. et al. Transient climate response in a two-layer energy-balance model. Part II: representation of the efficacy of deep-ocean heat uptake and validation for CMIP5 AOGCMs. J. Clim. 26, 1859–1876 (2013).

    Article  Google Scholar 

  10. Senior, C. A. & Mitchell, J. F. B. Time-dependence of climate sensitivity. Geophys. Res. Lett. 27, 2685–2688 (2000).

    Article  CAS  Google Scholar 

  11. Winton, M., Takahashi, K. & Held, I. M. Importance of ocean heat uptake efficacy to transient climate change. J. Clim. 23, 2333–2344 (2010).

    Article  Google Scholar 

  12. Armour, K. C., Bitz, C. M. & Roe, G. H. Time-varying climate sensitivity from regional feedbacks. J. Clim. 26, 4518–4534 (2013).

    Article  Google Scholar 

  13. Li, C., von Storch, J.-S. & Marotzke, J. Deep-ocean heat uptake and equilibrium climate response. Clim. Dynam. 40, 1071–1086 (2013).

    Article  Google Scholar 

  14. Rose, B. E. J. et al. The dependence of transient climate sensitivity and radiative feedbacks on the spatial pattern of ocean heat uptake. Geophys. Res. Lett. 41, 1071–1078 (2014).

    Article  Google Scholar 

  15. Andrews, T., Gregory, J. M. & Webb, M. J. The dependence of radiative forcing and feedback on evolving patterns of surface temperature change in climate models. J. Clim. 28, 1630–1648 (2015).

    Article  Google Scholar 

  16. Gregory, J. M. & Andrews, T. Variation in climate sensitivity and feedback parameters during the historical period. Geophys. Res. Lett. 43, 3911–3920 (2016).

    Article  Google Scholar 

  17. Knutti, R. & Rugenstein, M. A. A. Feedbacks, climate sensitivity and the limits of linear models. Phil. Trans. R. Soc. A 373, 20150146 (2015).

    Article  Google Scholar 

  18. Rugenstein, M. A. A., Caldiera, K. & Knutti, R. Dependence of global radiative feedbacks on evolving patterns of surface heat fluxes. Geophys. Res. Lett. 43, 9877–9885 (2016).

    Article  Google Scholar 

  19. Richardson, M. et al. Reconciled climate response estimates from climate models and the energy budget of Earth. Nat. Clim. Change 6, 931–935 (2016).

    Article  Google Scholar 

  20. Knutti, R. & Hegerl, G. C. The equilibrium sensitivity of the Earth’s temperature to radiation changes. Nat. Geosci. 1, 735–743 (2008).

    Article  CAS  Google Scholar 

  21. Gregory, J. M. et al. An observationally based estimate of the climate sensitivity. J. Clim. 15, 3117–3121 (2002).

    Article  Google Scholar 

  22. Roe, G. H. & Armour, K. C. How sensitive is climate sensitivity? Geophys. Res. Lett. 38, L14708 (2011).

    Article  Google Scholar 

  23. Forster, P. M. Inference of climate sensitivity from analysis of Earth’s energy budget. Annu. Rev. Earth Planet. Sci. 44, 85–106 (2016).

    Article  CAS  Google Scholar 

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

  25. Armour, K. C. et al. Southern Ocean warming delayed by circumpolar upwelling and equatorward transport. Nat. Geosci. 9, 549–554 (2016).

    Article  CAS  Google Scholar 

  26. Zhou, C., Zelinka, M. D. & Klein, S. A. Impact of decadal cloud variations on the Earth’s energy budget. Nat. Geosci. 9, 871–874 (2016).

    Article  CAS  Google Scholar 

  27. Marvel, K. et al. Implications for climate sensitivity from the response to individual forcings. Nat. Clim. Change 6, 386–389 (2015).

    Article  Google Scholar 

  28. Held, I. M. et al. Probing the fast and slow components of global warming by returning abruptly to preindustrial forcing. J. Clim. 23, 2418–2427 (2010).

    Article  Google Scholar 

  29. Baker, M. B. & Roe, G. H. The shape of things to come: Why is climate change so predictable? J. Clim. 22, 4574–4589 (2009).

    Article  Google Scholar 

  30. Knutti, R. et al. Challenges in combining projections from multiple climate models. J. Clim. 23, 2739–2758 (2010).

    Article  Google Scholar 

  31. Andrews, T., Gregory, J. M., Webb, M. J. & Taylor, K. E. Forcing, feedbacks and climate sensitivity in CMIP5 coupled atmosphere-ocean climate models. Geophys. Res. Lett. 39, L09712 (2012).

    Google Scholar 

  32. Myhre, G. et al. New estimates of radiative forcing due to well mixed greenhouse gases. Geophys. Res. Lett. 25, 2715–2718 (1998).

    Article  CAS  Google Scholar 

  33. Kostov, Y., Armour, K. C. & Marshall, J. Impact of the Atlantic meridional overturning circulation on ocean heat storage and transient climate change. Geophys. Res. Lett. 41, 2108–2116 (2014).

    Article  Google Scholar 

  34. Meinshausen, M. et al. The RCP greenhouse gas concentrations and their extension from 1765 to 2300. Climatic Change 109, 213–241 (2011).

    Article  CAS  Google Scholar 

  35. Myhre, G. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 659–740 (IPCC, Cambridge Univ. Press, 2013).

    Google Scholar 

  36. Annan, J. D. & Hargreaves, J. C. On the generation and interpretation of probabilistic estimates of climate sensitivity. Climatic Change 104, 423–436 (2011).

    Article  Google Scholar 

  37. Lewis, N. An objective Bayesian improved approach for applying optimal fingerprint techniques to estimate climate sensitivity. J. Clim. 26, 7414–7429 (2013).

    Article  Google Scholar 

  38. Annan, J. D. Recent developments in Bayesian estimation of climate sensitivity. Curr. Clim. Change Rep. 1, 263–267 (2015).

    Article  Google Scholar 

Download references

Acknowledgements

The author thanks T. Andrews, J. Bloch-Johnson, A. Donohoe, P. Forster, R. Knutti, C. Proistosescu, G. Roe and M. Rugenstein for enlightening discussions.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Kyle C. Armour.

Ethics declarations

Competing interests

The author declares no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 2099 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Armour, K. Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks. Nature Clim Change 7, 331–335 (2017). https://doi.org/10.1038/nclimate3278

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nclimate3278

This article is cited by

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