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

Cowan, Tim and Indorf, Sabine and Hegerl, Gabriele C. and Harrington, Luke J. and Otto, Friederike E. L. (2020) Present-day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves. Nature Climate Change, 10 (6). pp. 505-510. ISSN 1758-678X


Abstract

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.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version in accordance with the copyright policy oft he publisher.
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Applied Climate Sciences (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Applied Climate Sciences (1 Aug 2018 -)
Date Deposited: 15 Jun 2020 23:59
Last Modified: 17 Jul 2020 05:15
Uncontrolled Keywords: heatwaves, Dust Bowl, climate model, drought
Fields of Research (2008): 04 Earth Sciences > 0401 Atmospheric Sciences > 040104 Climate Change Processes
04 Earth Sciences > 0401 Atmospheric Sciences > 040107 Meteorology
04 Earth Sciences > 0401 Atmospheric Sciences > 040102 Atmospheric Dynamics
04 Earth Sciences > 0406 Physical Geography and Environmental Geoscience > 040604 Natural Hazards
04 Earth Sciences > 0401 Atmospheric Sciences > 040105 Climatology (excl.Climate Change Processes)
Identification Number or DOI: https://doi.org/10.1038/s41558-020-0771-7
URI: http://eprints.usq.edu.au/id/eprint/38803

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