Recent international negotiations and domestic policy developments have generated interest in current and projected U.S. greenhouse gas (GHG) emission levels. GHG emissions are generated throughout the United States from millions of discrete sources. Of the GHG source categories, carbon dioxide (CO2) emissions from fossil fuel combustion account for the largest percentage (76%) of total U.S. GHG emissions. The Environmental Protection Agency (EPA) promulgated standards for CO2 emissions from existing electric power plants on August 3, 2015. The rule, known as the Clean Power Plan (CPP), is the subject of ongoing litigation involving a number of entities. On February 9, 2016, the Supreme Court stayed the rule for the duration of the litigation. This book examines recent trends in U.S. GHG emissions, particularly CO2 emissions from electricity generation, and the factors that impact emission levels in that sector. In addition, this book examines the degree to which CPP implementation (or lack thereof) may impact CO2 emission levels from electric power plants.