U.S. energy related carbon emissions in 2017 dropped 0.9 percent from the prior year and 14 percent below 2005 levels, according to a Sept. 25 report from the U.S. Energy Information Administration. Although the gross domestic product grew by 2.3 percent from 2016 to 2017, the agency said that emissions were more than offset by a decline in carbon intensity in energy supply, energy intensity, and overall economy. Natural gas replacing coal in the power sector and increasing generation from non-carbon sources have lowered the carbon intensity of electricity generation. From 1990 to 2017, the share of coal in power generation fell to 30 percent from 52 percent, while the share of natural gas rose to 32 percent from 12 percent. While nuclear remains the main source of carbon-free power, wind and solar continue to grow, accounting for 22 percent of carbon-free power last year, from less than one percent in 2000, decreasing the carbon intensity of the electricity supply. Of the four end-use sectors, transportation produced the most emissions, with a 0.8 percent increase. Industrial, commercial, and residential sector emissions fell by 1.3 percent, 2.1 percent, and 2.6 percent, respectively.