CRS report via FAS – U.S. Carbon Dioxide Emission Trends and the Role of the Clean Power Plan, Jonathan L. Ramseur, Specialist in Environmental Policy. April 11, 2016.

“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 electric power sector contributes the largest percentage (39%) of CO2 emissions from fossil fuel combustion. In the context of international climate change negotiations, President Obama announced, on separate occasions, U.S. GHG emission reduction goals for both 2020 and 2025: 17% below 2005 levels by 2020 and 26% to 28% below 2005 levels by 2025. In 2014, U.S. GHG levels were 7.5% below 2005 levels. Whether the United States achieves its goals would likely depend, to some degree, on CO2 emissions from power plants. 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.”