Figure compares TD estimates of emissions for six different U.S. landfills reported across eight studies and U.S. Greenhouse Gas Reporting Program (GHGRP) self-reported emissions. In general, measured CH4 emissions from landfills were much larger than estimates of emissions by landfill operators submitted to the U.S. GHGRP; TD estimates of emissions for the six landfills in Figure were on average 2.6 times (± 1.8) higher than self-reported rates. While this mean was derived from the emissions data for the six landfills in Figure only, it aligns with the mean discrepancy (2.7 times) between TD aircraft estimates of point-source emissions and GHGRP self-reported rates for 96 U.S. landfills quantified in . The largest discrepancy in Figure was observed for the Charlotte Motor Speedway Landfill (1003099); TD estimates from four studies were on average 3.4 (± 0.5) times higher than the GHGRP self-reported rate for this landfill. The lowest mean discrepancy was observed for the Keller Canyon Landfill (1004011); TD estimates were 1.2 (± 0.6) times higher than the GHGRP self-reported rate. . The studies estimated both point-and area-source emissions for five out of the six landfills in Figure . For the Charlotte Motor Speedway Landfill (1003099) and the Newby Island Landfill (1006179), TD estimates mainly agree within uncertainties. The fact that point-and area-source measurement methods quantified comparable rates suggests that most emissions from these landfills may be related to large fugitive sources or intentional releases from discrete locations; point-source imagers cannot observe unoxidized landfill gas permeating through landfill cover soils as diffuse CH4 emissions. Point-source imagers attributed individual plumes to active/working faces, gaps in intermediate cover, construction of new waste cells or gas capture infrastructure, leaking gas capture wells, and unlit gas capture flares . Some of these sources can be targeted for abatement or mitigation; however, if surface activity is a proxy for the location of large emissions , then waste deposition and collection and modification of the landfill surface may rank highest in importance to total emissions for landfills.