Carbon dioxide emissions from U.S. energy consumption are expected to be relatively flat through 2050, according to the U.S. Energy Information Administration (EIA). The projection comes from the reference case in EIA’s Annual Energy Outlook 2019, and the case reflects no changes to existing law and regulations and extends existing trends in technology.
U.S. energy-related carbon dioxide (CO2) emissions are expected to decline 4% to 5.019 billion metric tons in 2050, from 2018. Emissions associated with coal and petroleum consumption should fall as emissions from natural gas consumption increase. In the United States, emissions associated with the consumption of petroleum fuels, such as motor gasoline, distillate and jet fuel, have accounted for the largest portion of CO2 emissions. In 2018, the transportation sector’s consumption accounted for 78% of U.S. CO2 emissions from petroleum and more than one-third of all U.S. energy-related CO2 emissions. Petroleum emissions from other sectors have declined recently as equipment and processes that use petroleum fuels have been replaced by those that use other fuels, particularly natural gas.
EIA’s reference case, which reflects existing regulations, projects that existing fuel economy standards stop requiring additional efficiency improvements in 2025 for light-duty vehicles and in 2027 for heavy-duty vehicles. Transportation consumption and emissions are expected to rise as travel demand continues to increase.
Natural gas CO2 emissions will continue to rise as natural gas use increases. The U.S. electric power sector is the largest consuming sector of natural gas and has added generating capacity from natural gas in recent years and has used those power plants more often. Natural gas surpassed coal in 2016 as the most prevalent fuel used to generate electricity in the United States.
By the mid-2020s, the industrial sector will again become the largest consumer of natural gas, according to the EIA. The sector uses natural gas as a feedstock in chemical industries, as lease and plant fuel, for industrial heat and power applications, and for liquefied natural gas production. Natural gas consumption also will continue to rise in the residential and commercial sectors. Natural gas furnaces and boilers will be used in 55% of U.S. homes in 2050, up from 49% in 2018.
Most coal CO2 emissions in the United States are from the electric power sector as only about 10% of coal CO2 emissions came from the industrial sector in 2018. The percentage is expected to remain flat through 2050. Nearly one-third of existing coal-fired capacity is expected to be retired over the next decade, but the remaining plants will be used more often, meaning coal’s projected decline in electricity generation isn’t as much as the capacity retirements would suggest.