U.S. energy-related carbon dioxide emissions fell in 2019, mainly in electric generation

After rising by 3% in 2018, energy-related carbon dioxide (CO2) emissions fell 3% in the United States in 2019. According to the U.S. Energy Information Administration’s (EIA) U.S. Energy-Related Carbon Dioxide Emissions, 2019 analysis, total energy-related CO2 emissions in 2019 were about 150 million metric tons (MMmt) lower than their 2018 level. EIA attributes nearly all (96%) of this decline to the changing mix of fuels used to generate electricity.

EIA calculates energy-related CO2 emissions by multiplying energy consumption, measured in British thermal units, by the appropriate carbon factor. The electric power sector accounted for nearly one-third of U.S. energy-related CO2 emissions in 2019; only the transportation sector emitted more CO2. Within the electric power sector, emissions from coal fell by 15% (177 MMmt) in 2019, and emissions from natural gas increased by 7% (40 MMmt).

U.S. electric power sector emissions have fallen 33% from their peak in 2007 because less electricity has been generated from coal and more electricity has been generated from natural gas (which emits less CO2 when combusted) and non-carbon sources. U.S. total energy-related CO2 emissions have fallen 15% since their 2007 peak.

Nuclear and renewable sources of electricity generation that do not emit carbon dioxide collectively reached a record-high 38% share of U.S. electric generation in 2019. Much of this growth came from continued construction of solar and wind capacity. These changes in the composition of electricity generation, as well as improvements in energy efficiency, have led to a decrease in the total carbon intensity of electricity, which has fallen from 619 metric tons per megawatthour (mt/MWh) in 2005 to 408 mt/MWh in 2019.

U.S. CO2 emissions associated with energy consumption in the residential and commercial sectors stayed nearly the same in 2019. CO2 emissions from the industrial sector rose 1.1% (11 MMmt) because of increased industrial output. The transportation sector experienced a 0.2% (4 MMmt) decrease in emissions, breaking a six-year trend of steadily increasing emissions in this sector since 2012.

More information on changes in energy-related CO2 emissions in 2019, as well as trends in emissions since 1990, is available in EIA’s U.S. Energy-Related Carbon Dioxide Emissions, 2019 report. EIA’s most recent CO2 emissions data series are available in the Monthly Energy Review.

Principal contributor: Kevin Nakolan