A gradual shift away from coal-generated electricity in the U.S. has resulted in a drop in power-plant CO₂ pollution. April CO₂ power-plant emissions were nearly back to 1988 levels. Between April 1988 and April 2015 coal use for power generation decreased 17 percent, while the use of renewable sources, like solar, wind, and hydro, increased by more than 100 percent. Burning coal is considered to be the dirtiest method, in terms of CO₂ emissions, currently being used on a large scale to generate electricity.

Coal and natural gas are the fossil fuels most commonly burned to generate electricity. According to the U.S. Energy Information Administration (EIA), generating electricity from coal produces 75% more CO₂ emissions on average than generating the same amount of electricity from natural gas. It’s not stated if that figure includes CO₂ emissions released during the fuel extraction process. Solar, wind, and hydro produce essentially no CO₂ emissions when generating electricity. But like conventional power plants, even for renewable sources CO₂ pollution does occur during the material production, equipment manufacturing, and construction processes required to create power generating facilities.

For the month of April, U.S. electricity generation from natural gas exceeded that from coal for the first time in history, but since then, coal has regained the lead. The implementation of the EPA’s Clean Power Plan (CPP) is expected to result in a significant decrease in coal-fired generation in the future.