The emissions for the waste sector have decreased by 6 million metric tons (MMT) CO₂e (5.2 percent) between 2011 and 2018. Reported emissions for the sector decreased by 8 percent, from 114.9 MMT CO₂e in 2011 to 105.7 MMT CO₂e in 2017. The decrease in emissions was likely due to the significant reduction in the number of reporters. In 2017, there were 144 fewer facilities reporting than in 2011.

Over 80 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 86 MMT CO₂e in 2017, a decrease of 8 MMT CO₂e (8 percent). The decrease in emissions was driven by a reduction in the number of reporters (110 fewer landfills reported in 2017 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.

In 2018, the first increase in emissions was reported for this sector despite a continuing decrease in the number of reporters (4 fewer facilities reported in 2018 than in 2017). Reported emissions for the sector were 3.2 MMT CO₂e (3 percent) higher than 2017. Most of this increase was from MSW landfills, whose emissions were 2.8 MMT CO₂e (3.2 percent) more than reported in 2017. Similar increases were also reported for industrial landfills (0.64 percent), wastewater treatment (1.35 percent), and solid waste combustion (4 percent). The increase in emissions are likely due to increased economic growth in 2018.