Luo et al. (2026) Observation-constrained projections reveal less increase in future global terrestrial evapotranspiration

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-07-17
• Authors: Ning Ma
• DOI: 10.1016/j.agrformet.2026.111343

Research Groups

• Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
• University of Chinese Academy of Sciences

Short Summary

This study uses water-balance observations in large river basins to constrain future global terrestrial evapotranspiration (ET) trends projected by CMIP6 Earth system models. The results show that the raw CMIP6 ESM ensemble overestimates future global ET trend by 30% under low- and medium-emission scenarios, and by 43% under high-emission scenario.

Objective

• To refine future global terrestrial evapotranspiration (ET) trend projections using water-balance observations and Emergent Constraint approach

Study Configuration

• Spatial Scale: Global scale with a focus on large river basins
• Temporal Scale: Historical period of 1983–2014 and future period of 2015–2099

Methodology and Data

• Models used: CMIP6 Earth system models (ESMs)
• Data sources: Water-balance observations in large river basins, precipitation datasets (GPCC, CRU, GPCP), and GRACE mascon grids for terrestrial water storage anomalies

Main Results

• The raw CMIP6 ESM ensemble overestimates future global ET trend by 30% under low- and medium-emission scenarios, and by 43% under high-emission scenario.
• The Emergent Constraint approach reduces the inter-model variance in future global ET projections by approximately one-third.

Contributions

• This study provides a more reliable understanding of how global ET is likely to evolve in a changing climate.
• The Emergent Constraint approach can be used as a tool for constraining future global ET trends and reducing uncertainty in hydrological projections.

Funding

• This research was supported by the National Natural Science Foundation of China (Grant No. 91737206)

Citation

@article{Luo2026Observationconstrained,
  author = {Luo, Yiwen and Ma, Ning},
  title = {Observation-constrained projections reveal less increase in future global terrestrial evapotranspiration},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111343},
  url = {https://doi.org/10.1016/j.agrformet.2026.111343}
}