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

Nature, Published online: 26 August 2026; doi:10.1038/d41586-026-02480-xAnalysis 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.