Present-day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves


Substantial warming occurred across North America, Europe and the Arctic over the early twentieth century1, including an increase in global drought2, that was partially forced by rising greenhouse gases (GHGs)3. The period included the 1930s Dust Bowl drought4,5,6,7 across North America’s Great Plains that caused widespread crop failures4,8, large dust storms9 and considerable out-migration10. This coincided with the central United States experiencing its hottest summers of the twentieth century11,12 in 1934 and 1936, with over 40 heatwave days and maximum temperatures surpassing 44 °C at some locations13,14. Here we use a large-ensemble regional modelling framework to show that GHG increases caused slightly enhanced heatwave activity over the eastern United States during 1934 and 1936. Instead of asking how a present-day heatwave would behave in a world without climate warming, we ask how these 1930s heatwaves would behave with present-day GHGs. Heatwave activity in similarly rare events would be much larger under today’s atmospheric GHG forcing and the return period of a 1-in-100-year heatwave summer (as observed in 1936) would be reduced to about 1-in-40 years. A key driver of the increasing heatwave activity and intensity is reduced evaporative cooling and increased sensible heating during dry springs and summers.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Observed Dust Bowl heatwave conditions in 1936.
Fig. 2: Simulated Dust Bowl HWF in 1934 and 1936 for strong heatwave summers.
Fig. 3: Role of spring precipitation in summer heatwave conditions.
Fig. 4: Return period HWF for central United States.

Data availability

Source Data for Figs. 3 and 4 are available with the manuscript, and Source Data for Figs. 1, 3 and 4 as well as Extended Data Fig. 3 are available at The BEST gridded product can be downloaded from The GHCN-D archive can be accessed from The WAH2 experiments were coordinated through the Environmental Change Institute at the University of Oxford and can be made available on request.

Code availability

The code to generate the main figures and Extended Data figures is available at: The code to calculate weather analogues, including installation, is publicly available from Information on its use is available at All supplementary figure code is available on request. Spatial plots are produced using NCAR Command Language (v.6.4.0; Return period two-dimensional plots are generated using Grace v.5.1.25 (


  1. 1.

    Hegerl, G. C., Brönnimann, S., Schurer, A. & Cowan, T. The early 20th century warming: anomalies, causes, and consequences. WIREs Clim. Change 9, e522 (2018).

  2. 2.

    Marvel, K. et al. Twentieth-century hydroclimate changes consistent with human influence. Nature 569, 59–65 (2019).

    CAS  Article  Google Scholar 

  3. 3.

    Hegerl, G. et al. Causes of climate change over the historical record. Environ. Res. Lett. 14, 123006 (2019).

  4. 4.

    Worster, D. Dust Bowl: The Southern Plains in the 1930s (Oxford Univ. Press, 1979).

  5. 5.

    Schubert, S. D., Suarez, M. J., Pegion, P. J., Koster, R. D. & Bacmeister, J. T. Causes of long-term drought in the U.S. Great Plains. J. Clim. 17, 485–503 (2004).

    Article  Google Scholar 

  6. 6.

    Brönnimann, S. et al. Exceptional atmospheric circulation during the ‘Dust Bowl’. Geophys. Res. Lett. 36, L08802 (2009).

    Article  Google Scholar 

  7. 7.

    Hoerling, M., Quan, X.-W. & Eischeid, J. Distinct causes for two principal U.S. droughts of the 20th century. Geophys. Res. Lett. 36, L19708 (2009).

    Article  Google Scholar 

  8. 8.

    Glotter, M. & Elliott, J. Simulating US agriculture in a modern Dust Bowl drought. Nat. Plants 3, 16193 (2016).

    Article  Google Scholar 

  9. 9.

    Cook, B. I., Seager, R. & Smerdon, J. E. The worst North American drought year of the last millennium: 1934. Geophys. Res. Lett. 41, 7298–7305 (2014).

    Article  Google Scholar 

  10. 10.

    Gutmann, M. P. et al. Migration in the 1930s: beyond the Dust Bowl. Soc. Sci. Hist. 40, 707–740 (2016).

  11. 11.

    DeGaetano, A. T. & Allen, R. J. Trends in twentieth-century temperature extremes across the United States. J. Clim. 15, 3188–3205 (2002).

    Article  Google Scholar 

  12. 12.

    Abatzoglou, J. T. & Barbero, R. Observed and projected changes in absolute temperature records across the contiguous United States. Geophys. Res. Lett. 41, 6501–6508 (2014).

    Article  Google Scholar 

  13. 13.

    Kohler, J. P. Weather of 1936 in the United States. Mon. Weather Rev. 65, 12–16 (1937).

    Article  Google Scholar 

  14. 14.

    Cowan, T. et al. Factors contributing to record-breaking heat waves over the Great Plains during the 1930s Dust Bowl. J. Clim. 30, 2437–2461 (2017).

    Article  Google Scholar 

  15. 15.

    State of the Climate: National Climate Report for August 2018 (NOAA, 2018).

  16. 16.

    Cook, B. I., Miller, R. L. & Seager, R. Amplification of the North American ‘Dust Bowl’ drought through human-induced land degradation. Proc. Natl Acad. Sci. USA 106, 4997–5001 (2009).

    CAS  Article  Google Scholar 

  17. 17.

    Donat, M. G. et al. Extraordinary heat during the 1930s US Dust Bowl and associated large-scale conditions. Clim. Dynam. 46, 413–426 (2016).

    Article  Google Scholar 

  18. 18.

    King, A. D. et al. Emergence of heat extremes attributable to anthropogenic influences. Geophys. Res. Lett. 43, 3438–3443 (2016).

    Article  Google Scholar 

  19. 19.

    Otto, F. E. L. Attribution of weather and climate events. Annu. Rev. Environ. Resour. 42, 627–646 (2017).

    Article  Google Scholar 

  20. 20.

    Guillod, B. P. et al. weather@home 2: validation of an improved global–regional climate modelling system. Geosci. Model Dev. 10, 1849–1872 (2017).

    Article  Google Scholar 

  21. 21.

    Undorf, S., Bollasina, M. A. & Hegerl, G. C. Impacts of the 1900–74 increase in anthropogenic aerosol emissions from North America and Europe on Eurasian summer climate. J. Clim. 31, 8381–8399 (2018).

    Article  Google Scholar 

  22. 22.

    Cook, B. I., Seager, R. & Miller, R. L. Atmospheric circulation anomalies during two persistent North American droughts: 1932–1939 and 1948–1957. Clim. Dynam. 36, 2339–2355 (2011).

    Article  Google Scholar 

  23. 23.

    Donat, M. G., Pitman, A. J. & Seneviratne, S. I. Regional warming of hot extremes accelerated by surface energy fluxes. Geophys. Res. Lett. 44, 7011–7019 (2018).

    Article  Google Scholar 

  24. 24.

    Hu, Z. & Huang, B. Interferential Impact of ENSO and PDO on dry and wet conditions in the U.S. Great Plains. J. Clim. 22, 6047–6065 (2009).

    Article  Google Scholar 

  25. 25.

    Kenyon, J. & Hegerl, G. Influence of modes of climate variability on global temperature extremes. J. Clim. 21, 3872–3889 (2008).

    Article  Google Scholar 

  26. 26.

    Ukkola, A. M., Pitman, A. J., Donat, M. G., De Kauwe, M. G. & Angélil, O. Evaluating the contribution of land–atmosphere coupling to heat extremes in CMIP5 models. Geophys. Res. Lett. 45, 9003–9012 (2018).

    Article  Google Scholar 

  27. 27.

    Mueller, N. D. et al. Cooling of US Midwest summer temperature extremes from cropland intensification. Nat. Clim. Change 6, 317–322 (2016).

    Article  Google Scholar 

  28. 28.

    Thiery, W. et al. Present-day irrigation mitigates heat extremes. J. Geophys. Res. 122, 1403–1422 (2017).

    Google Scholar 

  29. 29.

    Alter, R. E., Douglas, H. C., Winter, J. M. & Eltahir, E. A. B. Twentieth century regional climate change during the summer in the central United States attributed to agricultural intensification. Geophys. Res. Lett. 45, 1586–1594 (2018).

    Article  Google Scholar 

  30. 30.

    Cook, B. I., Miller, R. L. & Seager, R. Dust and sea surface temperature forcing of the 1930s “Dust Bowl” drought. Geophys. Res. Lett. 35, L08710 (2008).

    Google Scholar 

  31. 31.

    Scanlon, B. R. et al. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley. Proc. Natl Acad. Sci. USA 109, 9320–9325 (2012).

    CAS  Article  Google Scholar 

  32. 32.

    Diffenbaugh, N. S. & Ashfaq, M. Intensification of hot extremes in the United States. Geophys. Res. Lett. 37, 1–5 (2010).

    Article  Google Scholar 

  33. 33.

    Mann, H. B. & Whitney, D. R. On a test of whether one of two random variables is stochastically larger than the other. Ann. Math. Stat. 18, 50–60 (1947).

    Article  Google Scholar 

  34. 34.

    Perkins, S. E. & Alexander, L. V. On the measurement of heat waves. J. Clim. 26, 4500–4517 (2012).

    Article  Google Scholar 

  35. 35.

    Grotjahn, R. et al. North American extreme temperature events and related large scale meteorological patterns: a review of statistical methods, dynamics, modeling, and trends. Clim. Dynam. 46, 1151–1184 (2016).

    Article  Google Scholar 

  36. 36.

    Gross, M. H., Alexander, L. V., Macadam, I., Green, D. & Evans, J. P. The representation of health-relevant heatwave characteristics in a regional climate model ensemble for New South Wales and the Australian Capital Territory, Australia. Int. J. Climatol. 37, 1195–1210 (2017).

    Article  Google Scholar 

  37. 37.

    Menne, M. J., Durre, I., Vose, R. S., Gleason, B. E. & Houston, T. G. An overview of the Global Historical Climatology Network-Daily database. J. Atmos. Oceanic Technol. 29, 897–910 (2012).

    Article  Google Scholar 

  38. 38.

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

    Article  Google Scholar 

  39. 39.

    Haustein, K. et al. Real-time extreme weather event attribution with forecast seasonal SSTs. Environ. Res. Lett. 11, 064006 (2016).

  40. 40.

    Wilks, D. S. On ‘field significance’ and the false discovery rate. J. Appl. Meteorol. Climatol. 45, 1181–1189 (2006).

    Article  Google Scholar 

  41. 41.

    Jézéquel, A., Yiou, P. & Radanovics, S. Role of circulation in European heatwaves using flow analogues. Clim. Dynam. 50, 1145–1159 (2018).

    Article  Google Scholar 

  42. 42.

    Compo, G. P. et al. The twentieth century reanalysis project. Q. J. R. Meteorol. Soc. 137, 1–28 (2011).

    Article  Google Scholar 

Download references


This study forms part of the Transition into the Anthropocene project, funded by European Research Council Advanced grant no. EC-320691 and was further supported by the EUCLEIA project funded by the European Union’s Seventh Framework Programme (FP7/200713) under grant agreement no. 607085 and the EUPHEME ERA4CS grant no. 690462 and the Sigrist Foundation. G.H. was also supported by the Wolfson Foundation and the Royal Society as a Royal Society Wolfson Research Merit Award holder (WM130060). T.C. was also supported by the Northern Australian Climate Program, with funding provided by Meat and Livestock Australia, the Queensland Government and University of Southern Queensland. S.U. was also supported by the Horizon 2020 project EUCP.

Author information




T.C. and G.H. designed the study. F.O. and L.H. designed the model experiments. L.H. conducted the model experiments. T.C. performed the analysis and wrote the first draft. S.U. provided analysis for the Pacific and Atlantic decadal variations. All authors helped in the discussions, writing, editing and revising.

Corresponding author

Correspondence to Tim Cowan.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Climate Change thanks Markus Donat, Deepti Singh and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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

Extended data

Extended Data Fig. 1 Observed Dust Bowl heatwave conditions in 1934.

A comparison between observations from (left) Global Historical Climatology Network-Daily (GHCN-D) stations, and (right) Berkley Earth Surface Temperature (BEST) for summer heatwave conditions averaged over 1934. These include a, b heatwave frequency (HWF), c, d, heatwave duration (HWD), and e, f, heatwave amplitude (HWA). The heatwave metrics are calculated against a 1920–2012 reference period. The outlined GHCN-D stations are those where 1934 was the year with the most heatwave days, and the longest and hottest events.

Extended Data Fig. 2 Comparison of simulated heatwave frequency between 1931 and 2015.

a–c, Average over top 200 ranked experiments that simulate the most summer heatwave days over the central US in 1931 for a, WAH21930s, b, WAH2PD; compared to c, WAH22015. d–f, Average over the bottom ranked experiments for d, WAH21930s, e, WAH2PD; compared to f, WAH22015.

Extended Data Fig. 3 Spatial maps of return period of the observed 1934 and 1936 HWF.

Return period of summer HWF for (a–c) 1934 and (d–f) 1936, for a, d, WAH21930s, b, e, WAH2PD, and c, f, WAH22015.

Supplementary information

Supplementary Information

Supplementary Figs. 1–9.

Source data

Source Data Fig. 3

Source data for series plots in Fig. 3.

Source Data Fig. 4

Source data for return period plots in Fig. 4.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Cowan, T., Undorf, S., Hegerl, G.C. et al. Present-day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves. Nat. Clim. Chang. 10, 505–510 (2020).

Download citation

Further reading


Quick links

Sign up for the Nature Briefing newsletter for a daily update on COVID-19 science.
Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing