• climate change;
  • nutrient limitation;
  • terrestrial carbon cycle

[1] A climate model, coupled to a sophisticated land model, is used to explore the impact of nitrogen and phosphorous limitations on carbon uptake under increasing atmospheric carbon dioxide concentration, or [CO2], from 1870 to 2009. Adding nitrogen limitation strongly reduces the capacity of land CO2 uptake under increasing [CO2]. The further limitation by phosphorous has a smaller impact on the global uptake of CO2. However, phosphorous limitation has a strong impact on regional carbon uptake: increasing CO2 sinks over North America and Eurasia and decreasing sinks over China and Australia. Thus, while the global carbon balance can be resolved with just nitrogen limitation, simulations of continental-scale carbon sinks will need to include the additional limitation of phosphorous through the 20th century.