Assessing Consistency in Fuel Consumed Between Activity-Based Wildfire Emission Estimates

Wildfire emission inventories exhibit large variability that complicates assessments of smoke impacts. Here we compare fuel consumed (in mass per burned area units) from multiple burn area-based and energy-based approaches for fires in the western US during 2020. Average fuel consumed can vary by up to factors of 2–16 between approaches across burn severity classes and fuel types. Fuel consumed estimates typically increase with burn severity, except for the energy-based approaches for forest land cover, where it decreases for high burn severity. Also, in contrast to other approaches, energy-based estimates decrease for tree cover greater than 40% regardless of burn severity class. This implies that corrections to the energy-based approach are likely needed across burn severity categories to account for canopy and smoke shading. The methodological recommendations provided would likely result in greater consistency between wildfire emission estimates and highlight the need to better constrain fuel loading and consumption.