Xing et al. (2026) Substantial contribution of land-atmosphere interactions to the intensification of compound drought and heatwave events under rising CO2

Identification

• Journal: Global and Planetary Change
• Year: 2026
• Date: 2026-09-13
• Authors: Ruofei Xing, Zefeng Chen, Jia Wei, Feifei Yuan, Shijie Li, Giovanni Forzieri, Huimin Wang, Luca Solari
• DOI: 10.1016/j.gloplacha.2026.105722

Research Groups

• National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, China
• Business School, Hohai University, Nanjing, China
• Department of Civil and Environmental Engineering, University of Florence, Florence, Italy
• Department of Land Surveying and Geo-Informatics, Research Institute for Sustainable Urban Development, The Hong Kong Polytechnic University, Hong Kong, China
• College of Hydrology and Water Resources, Hohai University, Nanjing, China
• Division of Water Resources Engineering, Lund University, Sweden
• College of Management and Economics, Tianjin University, Tianjin, China

Short Summary

This study investigates the contribution of land-atmosphere interactions to the global intensification of Compound Drought and Heatwave (CDHW) events under elevated atmospheric CO2 (eCO2), finding that these interactions significantly amplify CDHW duration, frequency, and magnitude, primarily driven by eCO2-induced reductions in transpiration.

Objective

• To investigate the contribution of land-atmosphere interactions to the global intensification of Compound Drought and Heatwave (CDHW) events under elevated atmospheric CO2 (eCO2).

Study Configuration

• Spatial Scale: Global (across most vegetated land).
• Temporal Scale: Idealized CO2 increase experiments (future climate scenarios under rising CO2).

Methodology and Data

• Models used: Eleven Earth System Models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6), specifically using idealized CO2 increase experiments (fully-coupled and radiatively-coupled).
• Data sources: Output from Earth System Models (CMIP6).

Main Results

• While CO2 radiative forcing dominates the overall increase in CDHW events, land-atmosphere interactions further amplify CDHW intensification globally.
• This amplification contributes additional increases of 1.69 ± 1.53 days in duration, 2.52 ± 2.14 days in frequency, and 1.29 ± 1.12 °C² in magnitude.
• Amplification occurs across more than 94% of vegetated land and exhibits substantial spatial heterogeneity, with generally stronger increases identified in needleleaf forests.
• This widespread amplification is largely driven by reductions in transpiration associated with eCO2-induced decreases in stomatal conductance, despite concurrent vegetation greening.
• Specifically, larger transpiration reductions generally result in stronger CDHW intensification, accompanied by reduced evaporative cooling, enhanced sensible heating, decreased cloud cover and precipitation, and consequently stronger surface warming.

Contributions

• Quantifies the significant amplifying role of transpiration-mediated land-atmosphere interactions in the intensification of CDHW events under rising CO2.
• Highlights the importance of improved model representation of transpiration dynamics and associated land surface feedbacks for better constraining future risks associated with compound climate extremes.
• Provides a global assessment using a multi-model ensemble to differentiate the effects of CO2 radiative forcing from land-atmosphere interactions.

Funding

• Not explicitly listed in the provided text.

Citation

@article{Xing2026Substantial,
  author = {Xing, Ruofei and Chen, Zefeng and Wei, Jia and Yuan, Feifei and Li, Shijie and Forzieri, Giovanni and Wang, Huimin and Solari, Luca},
  title = {Substantial contribution of land-atmosphere interactions to the intensification of compound drought and heatwave events under rising CO2},
  journal = {Global and Planetary Change},
  year = {2026},
  doi = {10.1016/j.gloplacha.2026.105722},
  url = {https://doi.org/10.1016/j.gloplacha.2026.105722}
}