Qian et al. (2026) Recent intensification of the negative physiological effect of CO2 on terrestrial evaporation

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-08-31
• Authors: Haiyang Qian, Weiguang Wang, Zefeng Chen, Akash Koppa, Guoshuai Liu, Jian Zeng, Jianyu Fu, Shuai Cheng, Diego G. Miralles
• DOI: 10.1016/j.jhydrol.2026.136332

Research Groups

• Zhejiang Institute of Hydraulics and Estuary (Zhejiang Institute of Marine Planning and Design), Hangzhou, China
• Yangtze Institute for Conservation and Development, Hohai University, Nanjing, China
• Hydro-Climate Extremes Lab (H-CEL), Department of Environment, Ghent University, Ghent, Belgium
• Department of Civil and Environmental Engineering, University of Florence, Florence, Italy
• Department of Environmental Science and Technology, University of Maryland, College Park, MD, USA
• School of Civil Engineering, Sun Yat-sen University, Guangzhou, Guangdong, China
• Eastern Institute of Technology, Ningbo, China

Short Summary

This study developed a novel analog framework to decouple and quantify the individual contributions of vegetation greening and stomatal conductance reduction, driven by atmospheric CO₂, to global terrestrial evaporation (ET) trends. The analysis revealed that the net physiological effect of CO₂ on ET was globally negative from 1982 to 2018, as stomatal conductance reductions increasingly outweighed the positive effect of greening.

Objective

• To decouple and quantify the respective contributions of vegetation greening and stomatal conductance reduction, both modulated by atmospheric CO₂, to global terrestrial evaporation trends.

Study Configuration

• Spatial Scale: Global, with specific mention of water-limited arid regions.
• Temporal Scale: 1982–2018.

Methodology and Data

• Models used: Global dynamic vegetation model ensemble from the TRENDY project.
• Data sources: Satellite observations (used for rigorous constraint).

Main Results

• The net physiological effect of atmospheric CO₂ on terrestrial evaporation (ET) was globally negative during the period 1982–2018.
• This negative effect is primarily due to stomatal conductance reductions overcoming the positive effect of vegetation greening.
• In water-limited arid regions, the decoupled physiological effect showed a near-zero positive response.
• The net negative physiological effect on ET has progressively intensified in recent decades as atmospheric CO₂ has increased.
• This intensification is expected to attenuate projected increases in ET driven by global warming and the accelerated water cycle.

Contributions

• Introduction of a novel analog framework to enable nonlinear process-based decoupling and quantification of the physiological effects of CO₂ on ET.
• Enhancement of the robustness of the direct negative response of ET to CO₂ through observation-constrained weighting.
• Quantification of the global net negative physiological effect of CO₂ on ET from 1982–2018, resolving debate on the relative contributions of stomatal reduction and greening.
• Identification of the intensification of this negative effect, highlighting its role in moderating future ET trends.

Funding

Not specified in the provided text.

Citation

@article{Qian2026Recent,
  author = {Qian, Haiyang and Wang, Weiguang and Chen, Zefeng and Koppa, Akash and Liu, Guoshuai and Zeng, Jian and Fu, Jianyu and Cheng, Shuai and Miralles, Diego G.},
  title = {Recent intensification of the negative physiological effect of CO2 on terrestrial evaporation},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136332},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136332}
}