Stacey et al. (2026) Future global water scarcity partially moderated by vegetation responses to rising CO 2

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-07-08
• Authors: Jessica Stacey, Richard Betts, Andrew James Hartley, Lina María Mercado, Nicola Gedney
• DOI: 10.5194/hess-30-4225-2026

Research Groups

• Global Systems Institute, University of Exeter
• Met Office Hadley Centre
• Faculty of Environment, Science & Economy, University of Exeter
• UK Centre for Ecology and Hydrology

Short Summary

This study investigates the influence of vegetation responses to rising CO2 on water scarcity projections. The results suggest that incorporating these responses can partially alleviate water scarcity in most regions, mainly due to reduced stomatal opening.

Objective

• Investigate the impact of vegetation responses to rising CO2 on water scarcity projections

Study Configuration

• Spatial Scale: Global scale with a focus on 46 land regions and river basins
• Temporal Scale: Future period from 2006 to 2100 under Representative Concentration Pathway (RCP) 6.0

Methodology and Data

• Models used: Joint UK Land Environment Simulator (JULES)
• Data sources: Climate model output from HadGEM2-ES, water demand data from ISIMIP database

Main Results

• Incorporating vegetation responses to rising CO2 reduces global median Water Scarcity Index (WSI) by 12%
• CO2-induced stomatal closure increases runoff and soil moisture in many regions
• Climate-driven vegetation structural changes have a limited impact on runoff, soil moisture, and transpiration

Contributions

• This study highlights the importance of considering vegetation responses to rising CO2 in water scarcity assessments
• The results suggest that incorporating these responses can partially alleviate water scarcity in most regions

Funding

• Not specified

Citation

@article{Stacey2026Future,
  author = {Stacey, Jessica and Betts, Richard and Hartley, Andrew James and Mercado, Lina María and Gedney, Nicola},
  title = {Future global water scarcity partially moderated by vegetation responses to rising CO 2},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-4225-2026},
  url = {https://doi.org/10.5194/hess-30-4225-2026}
}