Rising CO2 and warming reduce global canopy demand for nitrogen

Nitrogen (N) limitation has been considered as a constraint on terrestrial carbon uptake in response to rising CO₂ and climate change. By extension, it has been suggested that declining carboxylation capacity (V_cmax ) and leaf N content in enhanced-CO₂ experiments and satellite records signify increasing N limitation of primary production. We predicted V_cmax using the coordination hypothesis and estimated changes in leaf-level photosynthetic N …