Substantial Differences in Compound Long‐Duration Dry and Hot Events Over China Between Transient and Stabilized Warmer Worlds at 1.5°C Global Warming

Abstract

AbstractPersistent hot and dry conditions could lead to serious impacts on society, economy, and human health. Using statistically downscaled and bias corrected data, we investigate the changes in compound long‐duration dry and hot (LDDH) events and the corresponding socioeconomic exposure over China in transient and stabilized warmer worlds. The transient response is identified with Coupled Model Intercomparison Project Phase 5 (CMIP5) and CMIP6 models, while the stabilized response is identified with the Community Earth System Model ensemble. Under 1.5°C and 2°C warming, the LDDH events in China will become more frequent and hotter. Substantial differences are found in LDDH features between transient and stabilized warming. For a given global temperature, the increase in frequency and temperature magnitude of LDDH events over most northern regions is significantly greater in a transient case than in a stabilized climate, while the increase over the southeastern China is substantially stronger under stabilized warming than transient warming. Future population exposure to LDDH events is projected to increase over China. For many regions, the aggregate exposure is two times greater in a transient climate than in a stabilized climate. Under transient warming, changes in LDDH events dominate the increase in population exposure whereas population change has smaller effects below 10%. For a stabilized warmer world, the negative population growth can largely offset the impact of climate change on exposure. Limiting global warming to 1.5°C instead of 2°C can reduce the exposure to LDDH events by 26.1% and 21.8% over China under transient and stabilized warming, respectively.