The emissions for the waste sector have decreased by 4.6 million metric tons (MMT) CO₂e (4.2 percent) between 2011 and 2019. Reported emissions for the sector decreased from 114.9 MMT CO₂e in 2011 to 110.3 MMT CO₂e in 2019. The decrease in emissions was likely due to the significant reduction in the number of reporters. In 2019, there were 144 fewer facilities reporting than in 2011.

Over 75 percent of the emissions in this sector come from municipal solid waste (MSW) landfills. Reported emissions from MSW landfills dropped from 94 MMT CO₂e in 2011 to 91 MMT CO₂e in 2019, a decrease of 3 MMT CO₂e (3 percent). The decrease in emissions was driven by a reduction in the number of reporters (116 fewer landfills reported in 2019 than in 2011), and changes to the rule for calculating methane emissions from MSW landfills. Starting in reporting year 2013, MSW landfills are allowed to assume that a higher percentage of methane generated by the landfill is oxidized to CO₂ as it passes through the landfill soil cover, resulting in lower reported methane emissions.

Reported emissions for the sector were 1.7 MMT CO₂e (2 percent) higher in 2019 than 2018, despite a continuing decrease in the number of reporters (27 fewer facilities reported in 2019 than in 2018). Most of this increase in reported emissions is from MSW landfills, whose emissions were 3 MMT CO₂e (3.2 percent) more than reported in 2018. Emission decreases were reported for industrial landfills (2.4 percent) and solid waste combustion (8.6 percent) subsectors, while there was no substantial change in emissions for the wastewater treatment subsector. The increase in emissions from MSW landfills are likely due to increased economic growth in 2019.