Analysis of observations and model projections provides large-scale emergent constraints on the extent of CO2 fertilization, with estimated increases in gross primary productivity for both high-latitude and extratropical ecosystems under elevated atmospheric CO2 concentrations.

The Hadley Centre coupled climate

The Amazon rainforest plays a crucial role in the climate system, helping to drive atmospheric circulations in the tropics by absorbing energy and recycling about half of the rainfall that falls on it. This region (Amazonia) is also estimated to contain about onetenth of the total carbon stored in land ecosystems, and to account for one-tenth of global, net primary productivity.