HOUSTON, Oct. 29 (Xinhua) -- U.S. electric power sector carbon dioxide (CO2) emissions have declined by 28 percent since 2005, the U.S. Energy Information Administration (EIA) said on Monday.
Carbon dioxide emissions from the electric power sector amounted to 1,744 million metric tons in 2017, the lowest level since 1987, the EIA said, adding that slower electricity demand growth and changes in fuels used to generate electricity have contributed to the decline.
The EIA said that U.S. electricity demand has decreased in six of the past 10 years. The average declining rate was 0.1 percent per year, and the lower demand growth alone has reduced emissions by 654 tons.
The switching among fossil fuels has also reduced emissions by 329 tons. The power sector has become less carbon intensive partly as natural gas-fired generation took over coal-fired and petroleum-fired generation. In 2016, natural gas generation surpassed coal as the largest source of electricity generation.
The growing noncarbon sources of electricity generation, especially renewables such as wind and solar, have also led to a less carbon intensive power sector.
Increases in electricity generation from noncarbon power sources since 2005 also had an effect on emissions from power generation, reducing emissions by 316 tons. In 2005, noncarbon sources accounted for 28 percent of the U.S. electricity mix. By 2017, that share grew to 38 percent.
Almost all of this growth was in renewables, including wind and solar, as shares for other noncarbon sources such as nuclear and hydroelectricity remained relatively flat.
In the United States, most of the changes in energy-related carbon dioxide emissions have been in the power sector. Since 2005, as electric power sector carbon dioxide emissions fell by 28 percent, carbon dioxide emissions from all other energy sectors fell by only 5 percent.
