The most at-risk regions in the world for high-impact heatwaves

Journal article

The last decade has seen numerous record-shattering heatwaves in all corners of the globe. In the aftermath of these devastating events, there is interest in identifying worst-case thresholds or upper bounds that quantify just how hot temperatures can become. Generalized Extreme Value theory provides a data-driven estimate of extreme thresholds; however, upper bounds may be exceeded by future events, which undermines attribution and planning for heatwave impacts. Here, we show how the occurrence and relative probability of observed yet unprecedented events that exceed a priori upper bound estimates, so-called “impossible” temperatures, has changed over time. We find that many unprecedented events are actually within data-driven upper bounds, but only when using modern spatial statistical methods. Furthermore, there are clear connections between anthropogenic forcing and the “impossibility” of the most extreme temperatures. Robust understanding of heatwave thresholds provides critical information about future record-breaking events and how their extremity relates to historical measurements

Authors: Thompson, V; Mitchell, D; Hegerl, GC; Collins, M; Leach, NJ

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Communications
• Volume: 14
• Issue: 1
• Pages: 2152-2152
• Article number: 2152
• Publication date: 2023-04-25
• DOI: 10.1038/s41467-023-37554-1
• EISSN: 2041-1723
• ISSN: 2041-1723
• Language: English
• Keywords: Ecology; Geography; Statistics; Extreme weather; Medicine; Climate change; Extreme heat; Environmental health; Event (particle physics); Population; Biology; Climatology; Extreme value theory; Climate extremes