The United States Environmental Protection Agency (U.S. EPA) recently released a report that is an inventory of greenhouse gas (GHG) emissions and sinks in the United States from 1990 – 2022. The inventory that identifies and quantifies a country’s anthropogenic sources and sinks of greenhouse gas emissions and removals and includes emissions from the waste industry.

The U.S. EPA’s latest inventory of greenhouse gas emissions also tallied emissions from municipal solid waste combustion and anaerobic digestion.

This Inventory adheres to both (1) a comprehensive and detailed set of methodologies for estimating national sources and sinks of anthropogenic greenhouse gases, and (2) a common and consistent format that enables Parties to the Paris Agreement and United Nations Framework Convention on Climate Change (UNFCCC) to compare the relative contribution of different greenhouse gases emissions and removals to climate change. The United States is party to both the 1992 UNFCCC and the 2015 Paris Agreement.

According to the inventory report, landfills were the third largest source of anthropogenic methane (CH4) in the United States in 2022, accounting for approximately 17.1 percent of total U.S. CH4 emissions. Additionally, composting of organic waste, and anaerobic digestion at biogas facilities accounted for approximately 0.4 percent, and less than 0.1 percent of U.S. CH4 emissions, respectively.

Nitrous oxide (N2O) emissions resulting from the discharge of wastewater treatment effluents into aquatic environments were estimated, along with the wastewater treatment process itself and composting. Together, these waste activities account for 6.1 percent of total U.S. N2O emissions.

Overall, in 2022, waste activities generated emissions of 166.9 MMT CO2 Eq., or 2.6 percent of total U.S. greenhouse gas emissions. Emissions from landfills contributed 71.8 percent of Waste sector emissions in 2022 and are primarily composed of CH4 emissions from municipal solid waste landfills. Landfill emissions decreased by 2.3 MMT CO2 Eq. (1.9 percent) since 2021. The remaining two sources of emissions, composting and anaerobic digestion at biogas facilities, account for 2.6 percent and less than 0.1 percent of Waste sector emissions in 2022, respectively.