Letter | Published:

Dramatically increasing chance of extremely hot summers since the 2003 European heatwave

Nature Climate Change volume 5, pages 4650 (2015) | Download Citation


Socio-economic stress from the unequivocal warming of the global climate system1 could be mostly felt by societies through weather and climate extremes2. The vulnerability of European citizens was made evident during the summer heatwave of 2003 (refs 3, 4) when the heat-related death toll ran into tens of thousands5. Human influence at least doubled the chances of the event according to the first formal event attribution study6, which also made the ominous forecast that severe heatwaves could become commonplace by the 2040s. Here we investigate how the likelihood of having another extremely hot summer in one of the worst affected parts of Europe has changed ten years after the original study was published, given an observed summer temperature increase of 0.81 K since then. Our analysis benefits from the availability of new observations and data from several new models. Using a previously employed temperature threshold to define extremely hot summers, we find that events that would occur twice a century in the early 2000s are now expected to occur twice a decade. For the more extreme threshold observed in 2003, the return time reduces from thousands of years in the late twentieth century to about a hundred years in little over a decade.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T.et al.) 867–952 (IPCC, Cambridge Univ. Press, 2013).

  2. 2.

    et al. in Climate Science for Serving Society: Research, Modeling and Prediction Priorities (eds Asrar, G. R. & Hurrell, J. W.) (Springer Science + Business Media, 2013).

  3. 3.

    et al. The role of increasing temperature variability in European summer heatwaves. Nature 427, 332–336 (2004).

  4. 4.

    The 2003 heat wave in Europe: A shape of things to come? An analysis based on Swiss climatological data and model simulations. Geophys. Res. Lett. 31, L02202 (2004).

  5. 5.

    et al. Death toll exceeded 70,000 in Europe during the summer of 2003. C. R. Biol. 331, 171–178 (2008).

  6. 6.

    , & Human contribution to the European heatwave of 2003. Nature 432, 610–613 (2004).

  7. 7.

    et al. Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods. Nature Clim. Change 1, 360–364 (2011).

  8. 8.

    , & Overestimated global warming over the past 20 years. Nature Clim. Change 3, 767–769 (2013).

  9. 9.

    & Recent global-warming hiatus tied to equatorial Pacific surface cooling. Nature 501, 403–407 (2013).

  10. 10.

    , , & No pause in the increase of hot temperature extremes. Nature Clim. Change 4, 161–163 (2013).

  11. 11.

    , , & Observed and simulated temperature extremes during the recent warming hiatus. Environ. Res. Lett. 9, 064023 (2014).

  12. 12.

    et al. Was there a basis for anticipating the 2010 Russian heat wave? Geophys. Res. Lett. 38, L06702 (2011).

  13. 13.

    & Increase of extreme events in a warming world. Proc. Natl Acad. Sci. USA 108, 17905–17909 (2011).

  14. 14.

    & Did we see the 2011 summer heat wave coming? Geophys. Res. Lett. 39, L09708 (2012).

  15. 15.

    & Anthropogenic contributions to Australia’s record summer temperatures of 2013. Geophys. Res. Lett. 40, 3705–3709 (2013).

  16. 16.

    , & Explaining extreme events of 2011 from a climate perspective. Bull. Am. Meteorol. Soc. 93, 1041–1067 (2012).

  17. 17.

    , , & Explaining extreme events of 2012 from a climate perspective. Bull. Am. Meteorol. Soc. 94, S1–S74 (2013).

  18. 18.

    , , & Explaining extreme events of 2013 from a climate perspective. Bull. Am. Meteorol. Soc. 95, S1–S96 (2014).

  19. 19.

    & Uncertainties in regional climate change prediction: A regional analysis of ensemble simulations with the HADCM2 coupled AOGCM. Clim. Dynam. 16, 169–182 (2000).

  20. 20.

    et al. Hemispheric and large-scale land surface air temperature variations: An extensive revision and an update to 2010. J. Geophys. Res. 117, D05127 (2012).

  21. 21.

    , & An overview of CMIP5 and the experimental design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

  22. 22.

    & Estimating signal amplitudes in optimal fingerprinting, part I: Theory. Clim. Dynam. 21, 477–491 (2003).

  23. 23.

    , & Attribution of observed historical near surface temperature variations to anthropogenic and natural causes using CMIP5 simulations. J. Geophys. Res. 118, 4001–4024 (2013).

  24. 24.

    , & Fast-track attribution assessments based on pre-computed estimates of changes in the odds of warm extremes. Clim. Dynam. (2014)

  25. 25.

    et al. The next generation of scenarios for climate change research and assessment. Nature 463, 747–756 (2010).

  26. 26.

Download references


This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and the EUCLEIA project funded by the European Union’s Seventh Framework Programme [FP7/2007–2013] under grant agreement no. 607085.

Author information


  1. Met Office Hadley Centre, FitzRoy Road Exeter EX1 3PB, UK

    • Nikolaos Christidis
    • , Gareth S. Jones
    •  & Peter A. Stott


  1. Search for Nikolaos Christidis in:

  2. Search for Gareth S. Jones in:

  3. Search for Peter A. Stott in:


N.C. organized the research, performed the analysis and wrote the paper. G.S.J. provided comments and data for the analysis. P.A.S. provided comments and contributed to the text.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Nikolaos Christidis.

Supplementary information

About this article

Publication history






Further reading