Total OS emissions. A) Annual CO₂ emissions for the OMI spatial domain from 2005 to 2020. GHGRP-reported CO₂ emissions for the surface mining facilities (colored fill) and in situ facilities (gray fill). Top–down estimates (ΣE_INV,T, ΣE_INV,C, ΣE_OMI,T, and ΣE_OMI,C) calculated using measured ERs (ER_T and ER_C) and scaling with OMI-derived NO_x (solid lines) and inventory NO_x (dashed lines). The shaded regions represent the propagated uncertainty. The solid orange square is the 2013 top–down estimate for surface mining facilities from Liggio et al.. The open orange square adds the reported CO₂ emissions from FBG + HTS + MACK to that estimate, and the upper error bar adds the mean top–down CO₂ emissions calculated in this study. B) Mean total top–down (solid bars) and GHGRP-reported (hatched bars) CO₂ emissions for the AOSR surface mining (teal) and in situ (peach) facilities with GHGRP-reported CH₄ emissions from all AOSR facilities (dark pink). The 2018–2020 means are the means across the four separate totals calculated using measured ERs (ER_T and ER_C) and scaling with TROPOMI-derived and inventory NO_x. The 2021 mean is the mean of the top–down estimates using TROPOMI-derived NO_x only. The error bars represent the propagated uncertainty.