Fig. 3: Contrast between sources in the official ECCC bottom-up inventory versus the presently derived hybrid measurement-based inventory.

a the ECCC national inventory and (b) the currently derived, hybrid measurement-based inventory (see also Table S6). Colours match where sources are equivalent in the two inventories. Hatched slices in the official inventory pie represent categories derived from reported data for which no further breakdown is possible. CHOPS = Cold Heavy Oil Production with Sand; SCVF = Surface Casing Vent Flow.