Increasing Socioeconomic Exposure to Compound Dry and Hot Events Under a Warming Climate in the Yangtze River Basin

Investigating changes in compound dry and hot events (CDHEs) and evaluating the associated socioeconomic exposure under climate change are critical for developing effective climate change mitigation and adaptation strategies. However, the socioeconomic exposure and the contributions of various driving factors to socioeconomic exposure under different warming levels remain poorly understood. Using the latest climate experiments from Coupled Model Intercomparison Project Phase 6 (CMIP6), this study assessed future changes in the frequency and socioeconomic exposure of CDHEs and explored the contributing drivers in the Yangtze River Basin (YRB) under 1.5 °C, 2.0 °C, and 3.0 °C global warming scenarios. Results indicate that the occurrences of CDHEs are projected to increase by 2.9, 3.9, and 4.8 times in a 1.5 °C, 2.0 °C, and 3.0 °C warmer world, respectively, compared to the present period (1985–2014). Population exposure to CDHEs increases significantly, with the greatest magnitude occurring at the 2 °C warming scenario. GDP exposure is expected to intensify continuously as the global average temperature rises, with the area experiencing significant increases continuously expanding. Climate change is the dominant driver of total projected changes in population exposure to CDHEs, accounting for approximately 105.6% at 1.5 °C, 110.3% at 2.0 °C, and 141.0% at 3.0 °C. At 1.5 °C, 2.0 °C, and 3.0 °C warming levels, changes in GDP exposure are primarily driven by the synergistic interaction between climate and GDP, accounting for 50.7%, 62.0%, and 64.8%, respectively. These findings provide valuable insights for climate change mitigation and adaptation strategies.