U.S. energy-related carbon dioxide emissions 1990-2021, by fuel type
On a percentage basis, coal emissions grew the fastest of all fossil fuel CO₂ emissions in 2021, at 14 percent. This was the the first annual increase in coal emissions since 2013, though they were the still the second lowest level for more than 30 years. Coal emissions have been in decline as this fossil fuels role in the U.S. power mix has been gradually replaced by other energy sources - primarily natural gas.