Energize Weekly, December 4, 2019
Carbon dioxide (CO2) emissions from energy-related activities in 2018 rose in the U.S. for the first time in five years, posting a 2.7 percent annual increase to 5.27 billion metric tons, according to the federal Energy Information Administration (EIA).
Driving the increase were higher emissions from natural gas-fired power generation, which was up as extreme summer temperatures sparked demand for air conditioning, and from transportation-related petroleum emissions, a result of the strong economy.
Energy-related CO2 emissions have declined in six of the last 10 years and had not risen since 2014. Emissions were still 12 percent lower in 2018 than they were in 2005, according to the EIA.
Coal-related CO2 emissions were down 4 percent in 2018, making coal the only fossil fuel with lower emission in 2018 than 2017.
Natural gas-fired electricity generation has been replacing coal plants, and in 2015, natural gas-related CO2 emissions surpassed coal emissions. Natural gas CO2 emissions were up 10 percent in 2018.
“Natural gas consumption and emissions increased in 2018 largely because of colder winter and hotter summer weather,” the EIA said. “Natural gas is both the most prevalent home heating fuel and the most prevalent fuel used to generate electricity.”
Emissions from petroleum related to transport activities were up 1.9 percent. Diesel fuel consumption, spurred by the economy, increased, and diesel-related CO2 emissions were up 6 percent.
Total U.S. electricity generation grew by 3.6 percent, but related CO2 emissions rose only 1.1 percent as cleaner natural gas replaced coal and more generation came from renewable sources, such as solar and wind.
“The shift from coal to natural gas lowers the CO2 emissions’ intensity because natural gas produces lower emissions per unit of energy used than coal and because natural gas-fired generators typically use less energy than coal plants to generate each kilowatt-hour of electricity,” the EIA said.
Residential and commercial sector CO2 emissions increased as a result of the weather, as a warmer summer led to increased electricity demand for cooling and a colder winter created more electricity demand for heating.
Residential CO2 emissions were up 7.4 percent, and commercial sector CO2 emissions increased 2.8 percent.
The energy intensity of economic growth has been markedly reduced. Between 2005 and 2018, the U.S. economy grew by 25 percent while U.S. energy consumption grew by 1 percent.
“The economic growth that occurred in 2018 was 29 percent less carbon-intensive than it was in 2005, and the overall energy consumption in the United States was 13 percent less carbon-intensive,” the EIA said.
