Savannah grass growth in dry conditions is boosted by increased CO2 levels

26 August 2026

Analysis of 70 experiments and 32 years of field observations shows that increasing the amount of carbon dioxide enhances the growth of the C4 group of grasses when water is limited. These findings challenge the assumption that C4 grasses respond weakly to changes in carbon dioxide level, and reveal an overlooked driver of change across the world’s savannahs.

This is a summary of: Simpson, K. J. et al. Increasing CO2 levels fertilize C4 grass production. Nature https://doi.org/10.1038/s41586-026-10935-4 (2026).

doi: https://doi.org/10.1038/d41586-026-02480-xFigure 1 is published under a CC BY 4.0 licence.

ReferencesChen, C., Riley, W. J., Prentice, I. C. & Keenan, T. F. Proc. Natl Acad. Sci. USA 119, e2115627119 (2022).Article