Global Wildland Fire Emissions of Full-Volatility Organic Compounds from 1997 to 2023

Wildland fires are significant sources of organic compounds, but traditional global fire emission inventories only include primary organic aerosols (POA) and volatile organic compounds (VOCs) and lack intermediate-volatility and semivolatile organic compounds (IVOCs and SVOCs), which could underestimate the environmental impact of wildland fires. We developed a global wildland fire organic emission inventory (1997-2023) with full-volatility coverage using volatility-binned and chemically specific emission factors by vegetation type. Compared to the traditional POA + VOC framework, full-volatility organic emission inventories filled a gap of 25.1 Mt/year of I/SVOCs; grassland, tropical forest, boreal forest, peatland, and temperate forest fires contributed 66%, 13%, 11%, 6%, and 4%, respectively, to full-volatility emissions (averaged over 1997-2023). Southern Hemisphere Africa was the top emission hotspot, with full-volatility organic emissions of 4.4 t/km²/year, 1.3-6.9 times greater than the next highest-emitting emission hotspots: Northern Hemisphere Africa, Southern Hemisphere South America, and Equatorial Asia. On a global scale, wildland fire organic emissions are 79% of anthropogenic organic emissions, but their I/SVOC emissions are comparable. With a more comprehensive consideration of the mass and chemical speciation of full-volatility organics, this emission inventory could enhance our understanding of the impact of wildland fires on air quality and human health.