The Environmental Protection Agency (EPA) has proposed regulations to reduce greenhouse gas (GHG) emissions from existing power plants. EPA believes that its proposed Clean Power Plan (CPP) will "protect public health, move the United States towards a cleaner environment, and fight climate change while supplying Americans with reliable and affordable power." Burning fossil fuels to produce electricity results in the release of carbon dioxide, and represents the largest source of GHG emissions in the United States. This book discusses the implications for the electric power sector. It also examines the carbon dioxide emission rate goals in EPA's proposed rule for existing power plants; and discusses the Congressional responses and options to the EPA regulation of greenhouse gases.