Global warming increases risk from compound dry‐hot events to human and agricultural systems

Abstract

Owing to their potentially amplified impacts, compound dry‐hot events (CDHEs) can pose serious risk to human life and ecosystems. However, studies have mainly assessed the risk related to CDHEs from the hazard or exposure perspective, while a system risk assessment incorporating the hazard, exposure and vulnerability at the global scale is lacking. This study assessed the risk from CDHEs based on model simulations from Coupled Model Intercomparison Project 6 (CMIP6) models for different future periods, including near term (2021–2040), mid‐term (2041–2060) and long term (2081–2100) periods, under two different Shared Socioeconomic Pathways (SSPs) scenarios. Using cropland and population as exposure indicators, the risk from CDHEs to human and agricultural systems was investigated by combing the hazard (the frequency or duration of CDHEs) and vulnerability indicators (GDP and irrigation fraction). Results showed a widespread increase in the risk to human and agricultural systems (represented by the populations and cropland) under the two scenarios (SSP2‐4.5 and SSP5‐8.5) across the globe, particularly in North America, Europe, Africa and Oceania for population and northern South America, large parts of Europe, and southeast China for cropland. The median values of relative changes in risk to human (cropland) systems were 136%, 213% and 207% (102%, 161% and 225%) for the near term, mid‐term and long term, respectively. The increase in hazards was shown to primarily contribute to the increased population risk. This study may provide useful insights for future risk management of compound extremes in human and agricultural systems.