U.S. electric power sector carbon dioxide emissions (CO2) have declined 28% since 2005 because of slower electricity demand growth and changes in the mix of fuels used to generate electricity. EIA has calculated that CO2 emissions from the electric power sector totaled 1,744 million metric tons (MMmt) in 2017, the lowest level since 1987.
In the United States, most of the changes in energy-related CO2 emissions have been in the power sector. Since 2005, as power sector CO2 emissions fell by 28%, CO2 emissions from all other energy sectors fell by only 5%. Slower electricity demand growth and changes in the electricity generation mix have played nearly equal roles in reducing U.S. power sector CO2 emissions.