Assessment of biomass open burning emissions in Indonesia and potential climate forcing impact

摘要

This paper presents an emission inventory (El) for biomass open burning (OB) sources including forest, agro-residue and municipal solid waste (MSW) in Indonesia for year 2007. The El covered toxic air pollutants and greenhouse gases (GHGs) and was presented as annual and monthly average for every district, and further on a grid of 0.25°×0.25°. A rigorous analysis of activity data and emission factor ranges was done to produce the low, best and high emission estimates for each species. Development of El methodology for MSW OB which, to our best knowledge, has not been presented in detail in the literature was a focus of this paper. The best estimates of biomass OB emission of toxic air pollutants for the country, in Gg, were: 9.6 SO_2; 98 NO_x; 7411 CO; 335 NMVOC; 162 NH_3; 439 PM_(10); 357 PM_(2.5); 24 BC; and 147 OC. The best emission estimates of GHGs, in Gg, were: 401 CH_4, 57,247 CO_2; and 3.6 N_2O. The low and high values of the emission estimates for different species were found to range from -86% to +260% of the corresponding best estimates. Crop residue OB contributed more than 80% of the total biomass OB emissions, followed by forest fire of 2-12% (not including peat soil fire emission) and MSW (1-8%). An inter-annual active fires count for Indonesia showed relatively low values in 2007 which may be attributed to the high rainfall intensity under the influence of La Nina climate pattern in the year. Total estimated net climate forcing from OB in Indonesia was 110 (20 year horizon) and 73 (100 year horizon) Tg CO_2 equivalents which is around 0.9-1.1% of that reported for the global biomass OB for both time horizons. The spatial distribution showed higher emissions in large urban areas in Java and Sumatra Island, while the monthly emissions indicated higher values during the dry months of August-October.