The issue of global warming has sparked debate among scientists and policymakers over the past two years. Many studies have been undertaken in the U.S. and other nations to determine the potential severity of global climate change and appropriate policy responses. The U.S. Department of Energy is now conducting one such study of energy technology and policy options to mitigate greenhouse gas emissions. The study attempts to assess the emissions reduction potential and costs of several policies, using the FOSSIL2 integrated energy model. This article focuses on the preliminary results of a subset of eight policy cases. It discusses the modeling methodology, the formulation of these policies, draft results, and some policy insights.