Green et al. (2026) Vegetation responses to air dryness amplify future land surface warming

Identification

• Journal: Nature Communications
• Year: 2026
• Date: 2026-05-11
• Authors: Julia K. Green, Trevor F. Keenan, Xu Lian, David J. P. Moore, Philippe Ciais
• DOI: 10.1038/s41467-026-73063-7

Research Groups

• Department of Environmental Science, University of Arizona, USA
• Department of Environmental Science, Policy, and Management, University of California, Berkeley, USA
• Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, USA
• Sino-French Institute for Earth System Science, Peking University, China
• School of Natural Resources and the Environment, University of Arizona, USA
• Laboratoire des Sciences du Climat et de l’Environnement, France

Short Summary

The study finds that canopy temperature is projected to increase significantly more than air temperature over the 21st century due to rising air dryness, implying that current Earth System Models (ESMs) underestimate future constraints on vegetation growth and the land carbon sink.

Objective

• To determine the extent to which canopy temperature (the temperature plants actually experience) diverges from air temperature under future climate scenarios and to assess how this divergence affects projections of ecosystem functions.

Study Configuration

• Spatial Scale: Global (focused on vegetated regions).
• Temporal Scale: 21st century.

Methodology and Data

• Models used: Earth System Model (ESM) ensemble (including CMIP6).
• Data sources: Satellite observations and ESM simulations.
• Approach: Application of a dual emergent constraint to bridge the gap between model simulations and observed satellite data.

Main Results

• Canopy temperature is projected to increase by approximately 0.11 K more than air temperature (representing a 16% increase in the difference between the two) over the 21st century.
• The ESM ensemble median fails to capture these amplified increases across the majority of vegetated regions.
• The largest increases in the canopy-air temperature gap occur in regions where rising vapor pressure deficit (VPD) increasingly limits transpiration and vegetation growth.
• Relying solely on air temperature leads to a systematic underestimation of temperature-driven constraints on photosynthesis and the land carbon sink.

Contributions

• The research identifies a critical gap in current ESMs by demonstrating that canopy temperature, rather than air temperature, is the primary driver of ecosystem function. It provides a quantitative basis for the underestimation of future land surface warming effects on the global carbon cycle.

Funding

• NASA (awards 80NSSC21K1705 and 80NSSC25K7327)
• RUBISCO SFA, sponsored by the Regional and Global Model Analysis (RGMA) Program in the Climate and Environmental Sciences Division (CESD) of the Office of Biological and Environmental Research (BER) in the U.S. Department of Energy (DOE) Office of Science
• DOE Early Career Research Program (award #DE-SC0021023)

Citation

@article{Green2026Vegetation,
  author = {Green, Julia K. and Keenan, Trevor F. and Lian, Xu and Moore, David J. P. and Ciais, Philippe},
  title = {Vegetation responses to air dryness amplify future land surface warming},
  journal = {Nature Communications},
  year = {2026},
  doi = {10.1038/s41467-026-73063-7},
  url = {https://doi.org/10.1038/s41467-026-73063-7}
}