The accumulation of greenhouse gases in the atmosphere over the past century is projected to cause a warming of the Earth. Climate change predictions vary by region and terrestrial biosphere response and feedbacks will be ecosystem specific. Forests play a major role in the Earth's carbon cycle through assimilation of CO2, storage of carbon, and emission of greenhouse gases. Simulation models have been employed to examine the possible responses to climate change of global forest ecosystems. Major shifts in forest species distribution and composition are predicted in response to projected climate change within the next 50-80 years. Preliminary evidence suggests the terrestrial biosphere could be managed to reduce accumulation of greenhouse gases in the atmosphere and mitigate negative impacts of climate change.