If its latest Short-Term Energy Outlook forecast holds, energy-related CO2 emissions will have declined in 7 of the 10 years from 2012 to 2021. With the anticipated declines, the 2021 level of fewer than 5 billion metric tons would be the first time emissions have been at that level since 1991.
Efficient combined-cycle gas turbine (CCGT) power units will keep replacing aging and more polluting coal-fired power stations, but the EIA sees the total share of fossil generation decline amid a strong rise in renewable power sources. Coal and natural gas electric generation combined, which had a 63 percent share of generation in 2018, fell to 62 percent in 2019, according to EIA figures, and is forecast to fall to 59 percent in 2020 and 58 percent in 2021.
Massive impact of fuel switching
Fuel switching in the power generation sector has a large impact on energy related emissions. In 2020, coal-related CO2 are seen fall 10.8 percent after plunging after declining by 12.7% in 2019 because of low natural gas prices. Coal-fired generation alone has fallen from 28 percent in 2018 to 24 percent in 2019 and will fall further to 21 percent in 2020 and 2021. The gas-fired generation share rises from 37 percent in 2019 to 38 percent in 2020, but it declines to 37 percent in 2021.
Natural gas -related emissions -- notably in the upstream sector and from gas-fired heating appliances -- increased 4.2 percent last year and is seen rising 1.4 percent in 2020, before falling 1.7 percent in 2021 due to warmer winter weather and less heating demand. The recent declines come after an increase in 2018 when weather-related factors pushed up emissions from the oil & gas upstream and power generation by 2.9 percent, the U.S. Energy Information Administration (EIA) noted.
Petroleum-related CO2 emissions are seen to remain flat in 2020 and decline slightly in 2021. More than two-thirds of U.S. petroleum consumption is for transportation, not least becomes miles traveled (VMT) keeps growing nearly 1% annually during the forecast period.