High-resolution estimation of air pollutant emissions from vegetation burning in China (2000-2018)

Vegetation burning in China contributes significantly to atmospheric pollution and climate change. However, most recent studies have focused on forest fires, ignoring grassland fires. Besides, there was a generally high uncertainty in the estimated fire emission because of missing small fire data and limited local vegetation data. This study employed high-resolution burned area data (GABAM, global annual burned area map) and land cover data to develop a high-resolution (30 m) emission inventory of vegetation burning in China in 2000, 2005, 2010, 2015, and 2018. Eleven pollutants were estimated, including CO, CH4, NOx, non-methane volatile organic carbon (NMVOC), SO2, NH3, PM2.5, PM10, organic carbon (OC), black carbon (BC), and CO2. The cumulative pollutant emissions from the temporal and spatial variation analyses of the burned area and emissions reached 1.21 x 10(5) Gg. Specifically, CO2 was the largest emission, with a mean annual emission of 2.25 x 10(4) Gg, accounting for 92.46% of the total emissions. CO was the second-largest emission, with a mean annual emission of 1.13 x 10(3) Gg. PM10 and PM2.5 emissions were also relatively high, with a mean annual emission of 200.5 and 140.3 Gg, respectively, with that of NMVOC (159.24 Gg) in between. The emissions of other pollutants, including OC, NOx, CH4, NH3, SO2, and BC, were relatively low. The South, Southwest, East, and Northeast of China contributed the most emissions. Shrubland contributed the most emissions for different vegetation types, followed by forest and grassland. Consequently, this study provides scientific evidence to support understanding the influence of fire on the local environment and policy on China's air pollution control.