From 1970 to 2011, emissions of major pollutants from coal-fueled power plants have been reduced by nearly 90% per unit of electricity generated.

According to the Energy Information Administration and Environmental Protection Agency data, emissions of sulfur dioxide, nitrogen oxides and particulate matter per kilowatt-hour from coal-fueled electricity generation have ben reduced by almost 90 percent over the period 1970-2011.

U.S. Energy Information Administration, Annual Energy Review 2011, http://www.eia.gov/aer/txt/ptb0802b.html and U.S. EPA, National Air Pollutant Emission Trends, 1970-2010, Fuel Combustion Electric Utilities, http://www.epa.gov/ttnchie1/trends/.