The forests of North America play an important role in the global greenhouse gas balance by removing carbon dioxide from the atmosphere and storing it in forest ecosystems and in products manufactured from harvested wood. Scientists from the Northern Research Station and cooperators from Canada and Mexico (sponsored by the Commission for Environmental Cooperation) worked to improve methods for assessing changes in forest carbon stocks of North America, and to develop tools for estimating, reporting, and projecting past and future forest greenhouse gas balances as affected by natural disturbances, forest management, and land-use change. Such information lays the foundation for policies aimed at reducing carbon emissions and enhancing carbon sequestration by forests. The policies include the reduction of emissions from deforestation and forest degradation, and increasing carbon stocks through sustainable forest management. The scientists compiled satellite and land inventory data, and tested computer models at study sites in Canada, the United States, and Mexico. Their results describe how different remotely sensed data and processing algorithms affect the mapping of areas affected by activities such as natural disturbances and harvesting, and the capabilities of different ecosystem models to assess the impacts of disturbances on productivity and carbon stocks.