Xu et al. (2026) Global drought shows no detectable recent acceleration under climate warming

Identification

• Journal: Communications Earth & Environment
• Year: 2026
• Date: 2026-09-11
• Authors: Jiameng Xu, Xiao Zhang, Kaighin A. McColl, Alexis Berg, Sha Zhou, Jian Yang, Zhaoyu Dong, Yuanyuan Luo, Yuanchao Fan
• DOI: 10.1038/s43247-026-03954-6

Research Groups

• Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
• Key Laboratory of Ecological Carbon Fixation and Sink Enhancement in Ordinary Universities of Guangdong Province, Guangzhou, China.
• Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA.
• School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
• Department of Geography, Université de Montréal, Montreal, QC, Canada.
• State Key Laboratory of Earth Surface Processes and Disaster Risk Reduction, Faculty of Geographical Science, Beijing Normal University, Beijing, China.
• Institute of Land Surface System and Sustainable Development, Faculty of Geographical Science, Beijing Normal University, Beijing, China.
• Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY, USA.

Short Summary

This study investigates the acceleration of global drought under climate warming using multiple potential evapotranspiration (PET) formulations. The results show that Penman-type PET methods overestimate drought trends, while energy-based PET methods provide a more physically consistent assessment of drought dynamics.

Objective

• Investigate the impact of different PET formulations on drought trend detection and acceleration analysis.
• Examine the role of land-atmosphere coupling constraints in estimating evaporative demand and its implications for drought indices.

Study Configuration

• Spatial Scale: Quasi-global (50°S–50°N) with a spatial resolution of 0.5° × 0.5°.
• Temporal Scale: 1981–2024, with an extension to 1950–2024 and 1901–2024 for sensitivity analysis.

Methodology and Data

• Models used:
  • Penman-type PET formulations (Penman, Penman-Monteith, etc.)
  • Energy-based PET formulations (Milly-Dunne, Yang-Roderick, Zhou-Yu, etc.)
  • Gallagher-McColl model for soil saturation analysis
  • Kim et al. framework for coupled PET estimation
• Data sources:
  • Satellite data (CHIRPS, MSWEP)
  • Meteorological datasets (MSWX100, ERA5-Land)

Main Results

• Penman-type SPEIs overestimate global drought trends by at least six times compared to energy-based SPEIs.
• Energy-based SPEIs show no significant acceleration of drought trends across ~99% of quasi-global land area under either PET type.
• The attribution analysis reveals that precipitation is the dominant driver of long-term hydroclimatic variations, while PET plays a lesser role.

Contributions

• This study provides a more physically consistent assessment of drought dynamics and highlights the importance of land-atmosphere coupling constraints in estimating evaporative demand.
• The results have implications for climate risk assessment and adaptation planning, emphasizing the need to consider multiple PET formulations and their structural uncertainties.

Funding

• Not specified in the provided text.

Citation

@article{Xu2026Global,
  author = {Xu, Jiameng and Zhang, Xiao and McColl, Kaighin A. and Berg, Alexis and Zhou, Sha and Yang, Jian and Dong, Zhaoyu and Luo, Yuanyuan and Fan, Yuanchao},
  title = {Global drought shows no detectable recent acceleration under climate warming},
  journal = {Communications Earth & Environment},
  year = {2026},
  doi = {10.1038/s43247-026-03954-6},
  url = {https://doi.org/10.1038/s43247-026-03954-6}
}