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Committed warming inferred from observations

Abstract

Due to the lifetime of CO2, the thermal inertia of the oceans1,2, and the temporary impacts of short-lived aerosols3,4,5 and reactive greenhouse gases6, the Earth’s climate is not equilibrated with anthropogenic forcing. As a result, even if fossil-fuel emissions were to suddenly cease, some level of committed warming is expected due to past emissions as studied previously using climate models6,7,8,9,10,11. Here, we provide an observational-based quantification of this committed warming using the instrument record of global-mean warming12, recently improved estimates of Earth’s energy imbalance13, and estimates of radiative forcing from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change14. Compared with pre-industrial levels, we find a committed warming of 1.5 K (0.9–3.6, 5th–95th percentile) at equilibrium, and of 1.3 K (0.9–2.3) within this century. However, when assuming that ocean carbon uptake cancels remnant greenhouse gas-induced warming on centennial timescales, committed warming is reduced to 1.1 K (0.7–1.8). In the latter case there is a 13% risk that committed warming already exceeds the 1.5 K target set in Paris15. Regular updates of these observationally constrained committed warming estimates, although simplistic, can provide transparent guidance as uncertainty regarding transient climate sensitivity inevitably narrows16 and the understanding of the limitations of the framework11,17,18,19,20,21 is advanced.

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Figure 1: Probabilities of transient climate response (TCR) and equilibrium climate sensitivity (ECS).
Figure 2: Estimates of committed warming under five different sets of assumptions.
Figure 3: Commitment as a function of transient climate response.

References

  1. Bryan, K., Komro, F. G., Manabe, S. & Spelman, M. J. Transient climate response to increasing atmospheric carbon dioxide. Science 215, 56–58 (1982).

    CAS  Article  Google Scholar 

  2. Wigley, T. M. L. The climate change commitment. Science 307, 1766–1769 (2005).

    CAS  Article  Google Scholar 

  3. Wigley, T. M. L. Could reducing fossil-fuel emissions cause global warming? Nature 349, 503–506 (1991).

    CAS  Article  Google Scholar 

  4. Hare, B. & Meinshausen, M. How much warming are we committed to and how much can be avoided? Climatic Change 75, 111–149 (2006).

    CAS  Article  Google Scholar 

  5. Ramanathan, V. & Feng, Y. On avoiding dangerous anthropogenic interference with the climate system: formidable challenges ahead. Proc. Natl Acad. Sci. USA 105, 14245–14250 (2008).

    CAS  Article  Google Scholar 

  6. Matthews, H. D. & Zickfeld, K. Climate response to zeroed emissions of greenhouse gases and aerosols. Nat. Clim. Change 2, 338–341 (2012).

    CAS  Article  Google Scholar 

  7. Archer, D. & Brovkin, V. The millennial atmospheric lifetime of anthropogenic CO2 . Climatic Change 90, 283–297 (2008).

    CAS  Article  Google Scholar 

  8. Solomon, S., Plattner, G.-K., Knutti, R. & Friedlingstein, P. Irreversible climate change due to carbon dioxide emissions. Proc. Natl Acad. Sci. USA 106, 1704–1709 (2009).

    CAS  Article  Google Scholar 

  9. Gillett, N. P., Arora, V. K., Zickfeld, K., Marshall, S. J. & Merryfield, W. J. Ongoing climate change following a complete cessation of carbon dioxide emissions. Nat. Geosci. 4, 83–87 (2011).

    CAS  Article  Google Scholar 

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

    Google Scholar 

  11. Frölicher, T. L., Winton, M. & Sarmiento, J. L. Continued global warming after CO2 emissions stoppage. Nat. Clim. Change 4, 40–44 (2014).

    Article  Google Scholar 

  12. Morice, C. P., Kennedy, J. J., Rayner, N. A. & Jones, P. D. Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: the HadCRUT4 data set. J. Geophys. Res. 117, D08101 (2012).

    Article  Google Scholar 

  13. Johnson, G. C., Lyman, J. M. & Loeb, N. G. Improving estimates of Earth’s energy imbalance. Nat. Clim. Change 6, 639–640 (2016).

    Article  Google Scholar 

  14. IPCC Climate Change 2013: The Physical Science Basis 1395–1446 (Cambridge Univ. Press, 2013).

  15. Adoption of the Paris Agreement Tech. Rep. FCCC/CP/2015/L.9/Rev.1 (UNFCC, 2015).

  16. Myhre, G., Boucher, O., Breon, F.-M., Forster, P. & Shindell, D. Declining uncertainty in transient climate response as CO2 forcing dominates future climate change. Nat. Geosci. 8, 181–185 (2015).

    CAS  Article  Google Scholar 

  17. Stevens, B. Rethinking the lower bound on aerosol radiative forcing. J. Clim. 28, 4794–4819 (2015).

    Article  Google Scholar 

  18. Richardson, M., Cowtan, K., Hawkins, E. & Stolpe, M. B. Reconciled climate response estimates from climate models and the energy budget of Earth. Nat. Clim. Change 6, 931–935 (2016).

    Article  Google Scholar 

  19. Marvel, K., Schmidt, G. A., Miller, R. L. & Nazarenko, L. S. Implications for climate sensitivity from the response to individual forcings. Nat. Clim. Change 6, 386–389 (2016).

    Article  Google Scholar 

  20. 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 

  21. Armour, K. C. Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks. Nat. Clim. Change 7, 331–335 (2017).

    Article  Google Scholar 

  22. Gregory, J. M., Stouffer, R. J., Raper, S. C. B., Stott, P. A. & Rayner, N. A. An observationally based estimate of the climate sensitivity. J. Clim. 15, 3117–3121 (2002).

    Article  Google Scholar 

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

    CAS  Article  Google Scholar 

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

    Article  Google Scholar 

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

    Google Scholar 

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

    Google Scholar 

  27. Armour, K. C. & Roe, G. H. Climate commitment in an uncertain world. Geophys. Res. Lett. 38, L01707 (2011).

    Article  Google Scholar 

  28. Hansen, J. et al. Climate response times: dependence on climate sensitivity and ocean mixing. Science 229, 857–859 (1985).

    CAS  Article  Google Scholar 

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

    CAS  Article  Google Scholar 

  30. 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).

    Article  Google Scholar 

  31. Sherwood, S. C. et al. Adjustments in the forcing-feedback framework for understanding climate change. Bull. Am. Meteorol. Soc. 96, 217–228 (2015).

    Article  Google Scholar 

  32. Gregory, J. M., Andrews, T., Good, P., Mauritsen, T. & Forster, P. M. Small global-mean cooling due to volcanic radiative forcing. Clim. Dynam. 47, 3979–3991 (2016).

    Article  Google Scholar 

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

    Google Scholar 

  34. Geoffroy, O. et al. Transient climate response in a two-layer energy-balance model. Part I: analytical solution and parameter calibration using CMIP5 AOGCM experiments. J. Clim. 26, 1841–1857 (2013).

    Article  Google Scholar 

  35. Gregory, J. M. et al. Climate models without preindustrial volcanic forcing underestimate historical ocean thermal expansion. Geophys. Res. Lett. 40, 1600–1604 (2013).

    Article  Google Scholar 

Download references

Acknowledgements

The work of T.M. is supported by the Max-Planck-Gesellschaft (MPG). R.P. is supported by the Regional and Global Climate Modeling Program of the US Department of Energy under grant DE-SC0012549 and by the National Science Foundation under grant ATM-1138394. The original motivation for this study arose at a preparation meeting for the IPCC special report on the 1.5 degree target (SR1.5) arranged by C. Textor and R. von Kuhlmann on behalf of the Federal Ministry for Education and Research in Germany (BMBF). The study benefited from comments and input from A. Dessler, J. Gregory, N. Lewis, V. Brovkin and P. Lanschützer.

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The original idea for this study was conceived by T.M. R.P. and T.M. developed the methodology and wrote the manuscript.

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Correspondence to Thorsten Mauritsen.

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The authors declare no competing financial interests.

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Mauritsen, T., Pincus, R. Committed warming inferred from observations. Nature Clim Change 7, 652–655 (2017). https://doi.org/10.1038/nclimate3357

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