Chen et al. (2025) The trend and interannual variability in the global terrestrial evapotranspiration are respectively dominated by humid regions and drylands

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-12-27
• Authors: Huiling Chen, Kun Zhang, Gaofeng Zhu, Lei Fan, Xin Li, Yunquan Wang, Xufeng Wang, Shasha Shang, Jia Jia, Yongtai Zhu, Jingfeng Xiao
• DOI: 10.1016/j.jhydrol.2025.134879

Research Groups

• College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
• College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China
• School of Geospatial Engineering and Science, Sun Yat-sen University, Zhuhai, China
• Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station, School of Geographical Sciences, Southwest University, Chongqing, China
• National Tibetan Plateau Data Center (TPDC), State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
• Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences at Wuhan, Wuhan, China
• Key Laboratory of Remote Sensing of Gansu Province, Heihe Remote Sensing Experimental Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
• Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin, China
• Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA

Short Summary

This study reveals that the increasing trend in global terrestrial evapotranspiration (ET) is predominantly driven by humid regions, while its substantial interannual variability (IAV) is primarily controlled by drylands.

Objective

• To identify the specific regions and underlying processes that govern the long-term increasing trend and interannual variability of global terrestrial evapotranspiration.

Study Configuration

• Spatial Scale: Global, with a focus on differentiating humid regions and drylands, particularly in the Northern Hemisphere and high latitudes.
• Temporal Scale: Long-term analysis from 1982 to 2020.

Methodology and Data

• Models used: Ensemble of process-based hydrological models, machine learning models, and land surface products.
• Data sources: Remote sensing-based products.

Main Results

• Humid regions, especially in the Northern Hemisphere, contribute 72.47 ± 5.77 % of the increase in global land ET from 1982 to 2020.
• In humid regions, climate warming and vegetation greening (increased leaf area index, LAI) caused ET increases of 0.43 ± 0.22 mm yr⁻² and 0.30 ± 0.13 mm yr⁻², respectively, with increased LAI being the largest contributor (63.69 ± 25.13 %) to global ET increases.
• Climate warming in humid high-latitude regions prolongs the growing season and provides sufficient water through freeze-thaw processes for enhanced plant photosynthesis.
• The interannual variability (IAV) of global land ET is dominated by drylands, contributing 59.66 ± 16.89 %.
• In drylands, the IAV is mainly attributed to large interannual oscillations in precipitation, linked to El Niño/Southern Oscillation (ENSO) events, with precipitation largely allocated to evaporation.
• Future anthropogenic warming is projected to continue increasing global land ET with significant interannual variations, maintaining and strengthening the dominant roles of humid regions and drylands.

Contributions

• Provides a clearer understanding of the divergent regional drivers (humid vs. drylands) for global terrestrial evapotranspiration trends and interannual variability.
• Quantifies the specific roles of climate warming, vegetation greening, and ENSO-driven precipitation variability in these distinct regions.
• Offers critical insights for understanding and projecting the dynamics of the global water cycle under future anthropogenic warming.

Funding

[Not explicitly mentioned in the provided paper text.]

Citation

@article{Chen2025trend,
  author = {Chen, Huiling and Zhang, Kun and Zhu, Gaofeng and Fan, Lei and Li, Xin and Wang, Yunquan and Wang, Xufeng and Shang, Shasha and Jia, Jia and Zhu, Yongtai and Xiao, Jingfeng},
  title = {The trend and interannual variability in the global terrestrial evapotranspiration are respectively dominated by humid regions and drylands},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134879},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134879}
}