Estimating Biomass Burning Emissions in South and Southeast Asia from 2001 to 2017 Based on Satellite Observations

Biomass burning emissions from forest fires, savanna fires, agricultural waste burning, and peatland combustion contain large amounts of trace gases and aerosols, which significantly impact ecosystem productivity, global atmospheric chemistry, and climate change. This study developed a high-resolution (0.1° × 0.1°), multi-year, monthly biomass burning emissions inventory including all land types in south and southeast Asia during 2001–2017. The inventory estimates are based on the MCD64A1 satellite burned area product, satellite and observational data of biomass, and spatiotemporal variable combustion factors. Results showed that during 2001–2017, the average annual biomass burning emissions in south and southeast Asia were 0.3 Tg BC, 2.7 Tg CH4, 52.0 Tg CO, 1010.3 Tg CO2, 0.7 Tg NH3, 10.8 Tg NMOC, 1.9 Tg NOx, 3.0 Tg OC, 5.1 Tg PM2.5, and 0.4 Tg SO2. Taking CO2 as an example, high emissions were observed in northwest India, west Myanmar, north Thailand, north Laos, east Cambodia, south Vietnam, south Sumatra and south Kalimantan of Indonesia, and south Papua New Guinea, respectively. Forest fire was found to be the largest contributor, accounting for 36% (363.2 Tg) of the total biomass burning CO2 emissions (1010.3 Tg). Meanwhile, Myanmar released 285.3 Tg CO2/year, being the largest emitter among all countries in south and southeast Asia. The total biomass CO2 emissions showed strong interannual variations with an increasing trend from 2001 to 2017. The annual peak emissions occurred during January–March. Forest fires and woody savanna/shrubland fires were the primary sources controlling the interannual and intra-annual emission characteristics.