A team of U.S. scientists has, for the first time, successfully incorporated the nitrogen cycle into global climate change simulations.

The experiment's findings at the Oak Ridge National Laboratory and the National Center for Atmospheric Research bring into question previous assumptions regarding carbon feedback.

The researchers say they determined the rate of climate change during the next century could be faster than previously anticipated when the requirement of plant nutrients are included in the climate model.

"We've shown that if all of the global modeling groups were to include some kind of nutrient dynamics, the range of model predictions would shrink because of the constraining effects of the carbon nutrient limitations, even though it's a more complex model," Oak Ridge scientist Peter Thornton said.

By taking the natural demand for nutrients into account, the authors demonstrated the stimulation of plant growth during the coming century might be two to three times smaller than previously predicted. Since less growth implies less carbon dioxide absorbed by vegetation, the CO2 concentrations in the atmosphere are expected to increase.

The detailed report is available in the journal Biogeosciences.