Work

Response of water cycle over drylands to a warming future

Year: 2025

Type: article

Abstract: Drylands stand as the most sensitive area to the climate change. Global warming accelerates the water cycle, significantly increasing the frequency of extreme climate hydrological events in drylands. Previous studies mainly discussed the response of a single element of the water cycle to global warming in drylands or focused on single hotspot region, but the synergistic relationship of various hydrological elements in the water cycle is not clear. Here, we investigate the response of the full process of water cycle to global warming over global drylands by utilizing the atmospheric and surface water budget based on multi-models projections (2021-2100) from Coupled Model Intercomparison Project Phase 6 (CMIP6). The results show that the water cycle in global drylands will accelerate with the annual precipitation (P) (multi-model median response of 6.71mm/K), evapotranspiration (E) (5.46 mm/K), precipitation minus evapotranspiration (P-E) (0.05 mm/K) and runoff (R) (2.48 mm/K) showing clear increasing trends. Conversely, the total soil moisture is expected to decrease at a rate of -0.64 mm/K. Warming influences the water cycle differently: regionally, it is expected to strengthen in East Asia’s drylands but weaken in South Africa’s; seasonally, the global drylands will experience an intensified water cycle during the dry season, while slightly weakened in the wet season. However, a significant decrease in soil moisture throughout the year and during the wet season heightened drought risk and lower agricultural yields. By moisture budget decomposition, we further find that the thermodynamic term negatively contributes to P, which is primarily attributed to the enhancement of moisture divergence, while the dynamic term partly offsets the effects of the thermodynamic term.

Source: Advances in Climate Change Research

DOI: 10.1016/j.accre.2025.09.005