Climate change will accelerate the high-end risk of compound drought and heatwave events

Abstract

Compound drought and heatwave (CDHW) events have garnered increased attention due to their significant impacts on agriculture, energy, water resources, and ecosystems. We quantify the projected future shifts in CDHW characteristics (such as frequency, duration, and severity) due to continued anthropogenic warming relative to the baseline recent observed period (1982 to 2019). We combine weekly drought and heatwave information for 26 climate divisions across the globe, employing historical and projected model output from eight Coupled Model Intercomparison Project 6 GCMs and three Shared Socioeconomic Pathways. Statistically significant trends are revealed in the CDHW characteristics for both recent observed and model simulated future period (2020 to 2099). East Africa, North Australia, East North America, Central Asia, Central Europe, and Southeastern South America show the greatest increase in frequency through the late 21st century. The Southern Hemisphere displays a greater projected increase in CDHW occurrence, while the Northern Hemisphere displays a greater increase in CDHW severity. Regional warmings play a significant role in CDHW changes in most regions. These findings have implications for minimizing the impacts of extreme events and developing adaptation and mitigation policies to cope with increased risk on water, energy, and food sectors in critical geographical regions.

Record-breaking and unprecedented compound hot and dry summers in Europe under different emission scenarios

“…In addition, our results confirm the findings in the existing literature based on GCMs (e.g. Liu et al 2021, Wu et al 2021, De Luca and Donat 2023, Tabari and Willems 2023, Tripathy et al 2023, highlighting the Mediterranean region as a hot-spot for future CHD events, which reinforce confidence in our results.…”

“…Although many studies exist analysing future projections for Europe of either droughts (Potopová et al 2018, Spinoni et al 2018, Toreti et al 2019, Hari et al 2020 or heatwaves (Molina et al 2020, Lin et al 2022, studies analysing future CHD events mainly focus on either the global scale (e.g. Liu et al 2021, Wu et al 2021, De Luca and Donat 2023, Tabari and Willems 2023, Tripathy et al 2023 or specific regions only, such as central Europe (Sedlmeier et al 2018, Zscheischler andFischer 2020). For instance, Wu et al (2021), Liu et al (2021), Tripathy et al (2023), Tabari and Willems (2023) and De Luca and Donat (2023) found that central Europe and the Mediterranean are amongst the regions showing stronger increase in frequency and intensity of CHD events through the late 21st century.…”

How Unusual Is the 2022 European Compound Drought and Heatwave Event?

“…In contrast, for the Balkans and Scandinavia the evaluated RPs are relatively less, with their median RPs are ∼75 and ∼50 years, respectively. As climate change continues to impact the planet, the RPs of CDHW events are becoming more likely to occur in the future (Tripathy et al., 2023; Zhang et al., 2022).…”

“…When these two events occur together (i.e., Compound Drought and Heatwaves (CDHW)), they can lead to even more severe consequences (Geirinhas et al., 2021; Hao et al., 2022; Libonati et al., 2022; Mukherjee & Mishra, 2021). In Europe, CDHW events have caused significant economic losses, affecting various sectors such as agriculture, health, energy, and tourism (Brás et al., 2021; Mazdiyasni & AghaKouchak, 2015; Tripathy et al., 2023; Yin et al., 2022; Zhou et al., 2019b). For instance, the 2003 heatwave and drought in Europe resulted in a total loss of €15 billion (European Environment Agency, 2023).…”

“…Mega drought and heatwave events occurred in the past, such as in 2003 (Fischer et al., 2007; García‐Herrera et al., 2010, p. 2; Stott et al., 2004), 2010 (Dole et al., 2011; Fischer, 2014; Liu et al., 2020), 2015 (Hauser et al., 2017; Ionita et al., 2017; Laaha et al., 2017; Lanen et al., 2016), and 2018 (Buras et al., 2020; Peters et al., 2020; Yiou et al., 2020). As global temperatures continue to rise, it is anticipated that the severity and frequency of droughts and heatwaves will become more intense in the future (Fischer et al., 2021; Hao et al., 2018; Perkins et al., 2012; Teuling, 2018; Trenberth et al., 2014; Tripathy et al., 2023).…”