The atmospheric concentration of greenhouse gases, most notably carbon dioxide, has gradually increased over the last century and, in the view of many climate scientists, is warming the global climate. Two policies of pricing carbon dioxide emissions and encouraging research and development of new carbon-reducing technologies, have been discussed as methods of limiting current and future emissions. This book examines available research on the role that these policies might play in encouraging cost-effective reductions in emissions as well as analysis on whether it would be more efficient to implement the policies simultaneously or sequentially.