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.