US GHG emissions post recent declineS. Himmelstein | April 19, 2021
The 28th annual Inventory of U.S. Greenhouse Gas Emissions and Sinks (GHG Inventory), which presents a national-level overview of annual greenhouse gas emissions from 1990 to 2019, has been issued by the U.S. Environmental Protection Agency (EPA). The GHG Inventory tracks carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride and nitrogen trifluoride. The system also calculates CO2 that is removed from the atmosphere through uptake in forests and other vegetation.
Net U.S. GHG emissions were 5,769 million metric tons of CO2-equivalent in 2019, a 1.7% decrease in emissions between 2018 and 2019. The downward GHG emissions trend can be largely attributed to falling emissions in the electric power sector. Emissions in 2019, after accounting for sequestration from the land sector, were 13% below 2005 levels.
Transportation activities are the largest source of emissions, accounting for 29% of total U.S. GHG emissions in 2019. From 1990 to 2019, transportation CO2 emissions from fossil fuel combustion rose by 24% due in large part to increased demand for travel.
Prior to the COVID-19 pandemic, 2020 fossil fuel combustion emissions were projected to decrease by about 2% compared to 2019, but preliminary 2020 data suggests that from 2019 to 2020, total energy use decreased by nearly 8% and fossil fuel combustion CO2 emissions decreased by roughly 11%. Overall electricity use decreased by 4% and the trend of decreased coal use and increased use of natural gas and renewables continued. Reduced economic and manufacturing activity resulted in lower energy use in the commercial and industrial sectors and there was a mixed impact on energy use in the residential sector due to stay-at-home orders increasing energy use combined with warmer temperatures leading to lower energy demand.