“After increasing in 2013 and 2014, energy-related carbon dioxide (CO2) emissions fell in 2015. In 2015, U.S. energy-related carbon dioxide emissions were 12% below the 2005 levels, mostly because of changes in the electric power sector . . . . Overall, the fuel-use changes in the power sector have accounted for 68% of the total energy-related CO2 reductions from 2005 to 2015.” –Energy Information Administration