Liu et al. (2025) Response of water cycle over drylands to a warming future

Identification

• Journal: Advances in Climate Change Research
• Year: 2025
• Date: 2025-09-25
• Authors: Chenxi Liu, Haipeng Yu, Yu Ren, Yun Wei, Wenxia Zhang, Lixia Zhang, Siyu Chen, Ruixia Guo, Jie Zhou
• DOI: 10.1016/j.accre.2025.09.005

Research Groups

• State Key Laboratory of Cryospheric Science and Frozen Soil Engineering, Nagqu Plateau Climate and Environment Observation and Research Station of Tibet Autonomous Region, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
• Lanzhou Regional Climate Centre/Gansu Meteorological Bureau, Lanzhou, China
• College of Atmospheric Sciences, Lanzhou University, Lanzhou, China
• Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China
• State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China

Short Summary

This study investigates the comprehensive response of the global dryland water cycle to future warming using CMIP6 multi-model projections, finding an overall acceleration of the water cycle but with significant regional and seasonal variations and increased drought risk.

Objective

• To holistically investigate the response of the full water cycle process (including atmospheric and land-surface components) and the synergistic relationships among its elements to global warming in global drylands, and to clarify the underlying mechanisms of precipitation changes.

Study Configuration

• Spatial Scale: Global drylands, divided into seven regions (East Asia, West and Central Asia, North Africa, North America, South America, South Africa, and Australia), and separated into Northern and Southern Hemisphere drylands.
• Temporal Scale: Historical period (1981—2010) and future projections (2021—2100), further analyzed in near-term (2021—2040), middle-term (2051—2070), and long-term (2081—2100) periods.

Methodology and Data

• Models used: Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model projections (15 global climate models) under the Shared Socio-economic Pathway 5 with a Representative Concentration Pathway of 8.5 W/m³ (SSP5-8.5) scenario.
• Data sources:
  • CMIP6 model simulations (historical and SSP5-8.5).
  • Fifth-generation ECMWF atmospheric reanalysis dataset (ERA5) for mean monthly evapotranspiration.
  • Climate Research Unit Time Series (Version 4.06) (CRU TS v4.06) for mean monthly precipitation.

Main Results

• The global dryland water cycle is projected to accelerate under global warming.
• Multi-model median responses show increasing trends for annual precipitation (P; 6.71 (3.12—10.07) mm/K), evapotranspiration (E; 5.46 (3.08—8.59) mm/K), precipitation minus evapotranspiration (P−E; 0.05 (−1.33—1.21) mm/K), and runoff (R; 2.48 (0.19—3.07) mm/K).
• Total soil moisture is projected to decrease at a rate of −0.64 (−8.85—3.59) mm/K, indicating exacerbated drought risk and reduced agricultural yields.
• Regionally, the water cycle is expected to strengthen in East Asia's drylands but weaken in South Africa's drylands.
• Seasonally, global drylands will experience an intensified water cycle in the wet season (P−E increase by 1.84 (−4.5—7.1) mm/K) but a slight decrease in the dry season (P−E decrease by −0.79 (−3.8—1.2) mm/K), characterized as "wetter in the wet season/drier in the dry season."
• Moisture-budget decomposition reveals that the thermodynamic term (−32.1 (−35.82 to −23.9) mm/K) negatively contributes to precipitation due to enhanced moisture divergence, partially offset by the positive contribution of the dynamic term (5.11 (1.54—7.36) mm/K).

Contributions

• Provides a holistic and comprehensive examination of the responses and coordinated relationships among all water cycle components (atmospheric and land-surface) across global drylands, addressing a gap in previous studies that focused on single elements or hotspot regions.
• Elucidates the underlying mechanisms of precipitation changes in global drylands by decomposing the atmospheric moisture budget into thermodynamic and dynamic contributions.
• Offers crucial insights into regional and seasonal variations of the dryland water cycle, which are significant for future adaptation strategies and sustainable water resource management.

Funding

• National Natural Science Foundation of China (U2442207)
• Youth Innovation Promotion Association of Chinese Academy of Sciences (2021427)
• West Light Foundation (xbzg-zdsys-202409) of the Chinese Academy of Sciences
• Central Guidance Fund for Local Science and Technology Development Projects in Gansu (24ZYQA031)
• Major Science and Technology Special Projects of Gansu Province (25ZDFA011)
• Open subject of Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions (LPCC2023004)

Citation

@article{Liu2025Response,
  author = {Liu, Chenxi and Yu, Haipeng and Ren, Yu and Wei, Yun and Zhang, Wenxia and Zhang, Lixia and Chen, Siyu and Guo, Ruixia and Zhou, Jie},
  title = {Response of water cycle over drylands to a warming future},
  journal = {Advances in Climate Change Research},
  year = {2025},
  doi = {10.1016/j.accre.2025.09.005},
  url = {https://doi.org/10.1016/j.accre.2025.09.005}
}