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:

Cumulative carbon emissions budgets consistent with 1.5 °C global warming


The Paris Agreement1 commits ratifying parties to pursue efforts to limit the global temperature increase to 1.5 °C relative to pre-industrial levels. Carbon budgets2,3,4,5 consistent with remaining below 1.5 °C warming, reported in the IPCC Fifth Assessment Report (AR5)2,6,8, are directly based on Earth system model (Coupled Model Intercomparison Project Phase 5)7 responses, which, on average, warm more than observations in response to historical CO2 emissions and other forcings8,9. These models indicate a median remaining budget of 55 PgC (ref. 10, base period: year 1870) left to emit from January 2016, the equivalent to approximately five years of emissions at the 2015 rate11,12. Here we calculate warming and carbon budgets relative to the decade 2006–2015, which eliminates model–observation differences in the climate–carbon response over the historical period9, and increases the median remaining carbon budget to 208 PgC (33–66% range of 130–255 PgC) from January 2016 (with mean warming of 0.89 °C for 2006–2015 relative to 1861–188013,14,15,16,17,18). There is little sensitivity to the observational data set used to infer warming that has occurred, and no significant dependence on the choice of emissions scenario. Thus, although limiting median projected global warming to below 1.5 °C is undoubtedly challenging19,20,21, our results indicate it is not impossible, as might be inferred from the IPCC AR5 carbon budgets2,8.

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

Fig. 1: Time series of global mean temperature and cumulative carbon emissions for RCP 4.5 and 8.5 scenarios.
Fig. 2: Cumulative total carbon budgets consistent with 1.5 °C warming (for RCP 4.5 and 8.5 scenarios) as a function of simulated cumulative fossil fuel carbon emissions at present warming.
Fig. 3: Cumulative frequency distribution of carbon budgets consistent with staying below 1.5 °C global warming.
Fig. 4: Cumulative frequency distribution of carbon budgets consistent with staying below 1.5 °C global warming based on all CMIP5 models considered here for two different base periods and five different observational data sets.

Similar content being viewed by others


  1. Adoption of the Paris Agreement FCCC/CP/2015/L.9/Rev.1 (UNFCCC, 2015);

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

  3. Allen, M. R. et al. Warming caused by cumulative carbon emissions towards the trillionth tonne. Nature 458, 1163–1166 (2009).

    Article  CAS  Google Scholar 

  4. Matthews, H. D., Gillett, N. P., Stott, P. A. & Zickfeld, K. The proportionality of global warming to cumulative carbon emissions. Nature 459, 829–832 (2009).

    Article  CAS  Google Scholar 

  5. Zickfeld, K. et al. Setting cumulative emissions targets to reduce the risk of dangerous climate change. Proc. Natl Acad. Sci. USA 106, 16129–16134 (2009).

    Article  CAS  Google Scholar 

  6. Rogelj, J. et al. Differences between carbon budget estimates unravelled. Nat. Clim. Change 6, 245–252 (2016).

    Article  Google Scholar 

  7. Taylor, K. E., Stouffer, R. J. & Meehl, G. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

    Article  Google Scholar 

  8. IPCC Summary for Policymakers. In Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).

  9. Millar, R. J. et al. Emission budgets and pathways consistent with limiting warming to 1.5 °C. Nat. Geosci. 10, 741–747 (2017).

    Article  CAS  Google Scholar 

  10. IPCC Climate Change 2014: Synthesis Report (eds Pachauri R. K. & Meyer L. A.) (Cambridge Univ. Press, 2014).

  11. Le Quéré, C. et al. Global carbon budget 2015. Earth Syst. Sci. Data 7, 349–396 (2015).

    Article  Google Scholar 

  12. Le Quéré, C. et al. Global carbon budget 2013. Earth Syst. Sci. Data 6, 235–263 (2014).

    Article  Google Scholar 

  13. 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. Atmos. 117, 1–22 (2012).

    Article  Google Scholar 

  14. Vose, R. S. et al. NOAA’s merged land-ocean surface temperature analysis. Bull. Am. Meteorol. Soc. 93, 1677–1685 (2012).

    Article  Google Scholar 

  15. GISTEMP Team GISS Surface Temperature Analysis (GISTEMP) (NASA Goddard Institute for Space Studies, 2018);

  16. Hansen, J., Ruedy, R., Sato, M. & Lo, K. Global surface temperature change. Rev. Geophys. 48, RG4004 (2010).

    Article  Google Scholar 

  17. Cowtan, K. & Way, R. G. Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends. Q. J. R. Meteorol. Soc. 140, 1935–1944 (2014).

    Article  Google Scholar 

  18. Rohde, R. et al. A new estimate of the average earth surface land temperature spanning 1753 to 2011. Geoinform. Geostat. Overview 1, (2013).

  19. Rogelj, J. et al. Energy system transformations for limiting end-of-century warming to below 1.5 °C. Nat. Clim. Change 5, 519–528 (2015).

    Article  Google Scholar 

  20. Sanderson, B. M., O’Neill, B. & Tebaldi, C. What would it take to achieve the Paris temperature targets? Geophys. Res. Lett. 43, 7133–7142 (2016).

    Article  Google Scholar 

  21. Schleussner, C.-F. et al. Science and policy characteristics of the Paris Agreement temperature goal. Nat. Clim. Change 6, 827–835 (2016).

    Article  Google Scholar 

  22. Van Vuuren, D. P. et al. The representative concentration pathways: an overview. Climatic Change 109, 5–31 (2011).

    Article  Google Scholar 

  23. Gillett, N. P. Weighting climate model projections using observational constraints. Phil. Trans. R. Soc. A 373, 20140425 (2015).

    Article  Google Scholar 

  24. Ehlert, D. & Zickfeld, K. What determines the warming commitment after cessation of CO2 emissions? Environ. Res. Lett. 12, 15002 (2017).

    Article  Google Scholar 

  25. MacDougall, A. H., Avis, C. A. & Weaver, A. J. Significant contribution to climate warming from the permafrost carbon feedback. Nat. Geosci. 5, 719–721 (2012).

    Article  CAS  Google Scholar 

  26. Schuur, E. A. G. et al. Climate change and the permafrost carbon feedback. Nature 520, 171–179 (2015).

    Article  CAS  Google Scholar 

  27. MacDougall, A. H., Zickfeld, K., Knutti, R. & Matthews, H. D. Sensitivity of carbon budgets to permafrost carbon feedbacks and non-CO2 forcings. Environ. Res. Lett. 10, 125003 (2015).

    Article  Google Scholar 

  28. Schaphoff, S. et al. Contribution of permafrost soils to the global carbon budget. Environ. Res. Lett. 8, 014026 (2013).

    Article  Google Scholar 

  29. Schurer, A. P. et al. Importance of the pre-industrial baseline for likelihood of exceeding Paris goals. Nat. Clim. Change 7, 563–567 (2017).

    Article  Google Scholar 

  30. Rogelj, J. et al. Impact of short-lived non-CO2 mitigation on carbon budgets for stabilizing global warming. Environ. Res. Lett. 10, 75001 (2015).

    Article  Google Scholar 

  31. 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).

  32. Stocker, T. F. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 33–115 (IPCC, Cambridge Univ. Press, 2013).

Download references


The authors thank M. Berkley for assistance with data acquisition, V. K. Arora and V. Kharin for providing comments on the initial version of the manuscript, and M. Eby, A. P. Schurer and A. R. Friedman for helpful discussions. The authors acknowledge support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant Program and the UK Natural Environment Research Council SMURPHS project (grant no. NE/N006143/1). The authors acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and thank the climate modelling groups for producing and making available their model output. For CMIP the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. The authors acknowledge Met Office Hadley Centre for providing observational HadCRUT4 data sets, K. Cowtan and R. Way for the filled-in HadCRUT4 data set, the Berkeley Earth Surface Temperature data set, NOAA/OAR/ESRL PSD for providing the NASA(GISS/GISTEMP and NOAAGlobalTemp) global surface temperature data.

Author information

Authors and Affiliations



N.P.G. designed the study. K.B.T. collected and analysed data. K.B.T. and N.P.G. interpreted the data and wrote the manuscript.

Corresponding author

Correspondence to Katarzyna B. Tokarska.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Tables 1–3, Supplementary Figures 1–3 and Supplementary References

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tokarska, K.B., Gillett, N.P. Cumulative carbon emissions budgets consistent with 1.5 °C global warming. Nature Clim Change 8, 296–299 (2018).

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