U.S. Greenhouse Gas Emissions Fell in the First Year of the Pandemic, New EPA Report Says
Net U.S. greenhouse gas emissions decreased 11% from 2019 to 2020, according to the U.S. Environmental Protection Agency (EPA)’s 29th annual Inventory of U.S. Greenhouse Gas Emissions and Sinks. The report, which was released on April 14, 2022, provides a nationwide overview of greenhouse gas emissions from all man-made sources.
The EPA calculates that U.S. greenhouse gas emissions totaled 5,222 million metric tons of carbon dioxide (CO2) equivalent in 2020 after accounting for sequestration from carbon sinks like forests, plants, and soil.
However, the reduction may be fleeting. “The sharp decline in emissions from 2019 to 2020 is largely due to the impacts of the coronavirus (COVID-19) pandemic on travel and economic activity,” the EPA said in a news release.
The reduction was largely driven by a decrease in CO2 emissions from fossil fuel combustion. The transportation sector, which generates the largest share of greenhouse gases, saw a 13% decrease in emissions in the first year of the pandemic. Preliminary data from the U.S. Energy Information Administration (EIA) suggests that transportation sector emissions increased 11% in 2021.
Still, not all of the drop can be attributed to COVID-19. Emissions from the electric power sector — the second largest source of greenhouse gases — decreased 10% in 2020. This reflects both a decrease in energy demand during the pandemic, as well as ongoing efforts to shift from fossil fuels to renewable energy.
The EPA inventory takes into account seven greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. Carbon dioxide was the main greenhouse gas contributing to U.S. emissions, representing 79% of the total emissions in 2020. Of that, 94% came from the burning of fossil fuels.
Image Source: EPA
The inventory also reveals trends in greenhouse gas emissions over time. Between 2005 and 2020, net U.S. greenhouse gas emissions declined 21%. The U.S. has pledged to reduce its carbon emissions at least 50% from 2005 levels.
The EPA has compiled an annual greenhouse gas inventory every year since 1990, enabling the agency and policymakers to track progress toward national emissions reduction targets.
“The annual Inventory reflects EPA’s ongoing commitment to strengthening the data that inform all of our actions on climate change,” said Joseph Goffman, Principal Deputy Assistant Administrator for the Office of Air and Radiation. “Each year, EPA follows a rigorous and open process to engage with researchers, federal partners and stakeholders and incorporate new information, resulting in a national Inventory that is unsurpassed in scope and quality.”
To prepare the inventory, the EPA collaborates with hundreds of experts from federal and state agencies, academic institutions, industry associations, consultants and environmental organizations. It also collects greenhouse gas emissions data from individual facilities and suppliers of certain fossil fuels and industrial gases through its Greenhouse Gas Reporting Program.
The EPA made several improvements to this year’s report, including adding estimates for two key methane sources: leak emissions from residential and commercial appliances, industrial facilities, power plants, and natural gas fueled vehicles; and emissions from flooded lands like hydroelectric and agricultural reservoirs. In addition, the EPA worked with researchers to estimate methane emissions from large anomalous leak events, such as well blow-outs.
Once completed, the report is submitted to the United Nations in accordance with the Framework Convention on Climate Change.