Assessment of co-benefits of black carbon emission reduction measures in Southeast Asia: Part 2 emission scenarios for 2030 and co-benefits on mitigation of air pollution and climate forcing

摘要

Following Part 1 (Permadi et al., 2017a) which focuses on the preparation of emission input data and evaluation of WRF/CHIMERE performance in 2007, this paper presents Part 2 of our research detailing the quantification of co-benefits resulted in the future (2030) from black carbon (BC) emission reduction measures for Southeast Asia (SEA) countries. The business as usual (BAU2030) projected emissions from the base year of 2007 (BY2007) assuming with the linear projection of the emissions based on the past decadal activity data (Indonesia and Thailand) and the sectoral GDP growth for other countries. The RED2030 featured measures to cut down emission in major four source sectors in Indonesia and Thailand (on-road transport, residential cooking, industry, and biomass open burning) while for other countries the representative concentration pathway 8.5 (RCP8.5) emissions were assumed. WRF/CHIMERE simulated levels of aerosol species under BAU2030 and RED2030 for the SEA domain using the base year meteorology and 2030 boundary conditions from LMDZ/INCA. The extended aerosol optical depth module (AODEM) calculated the total columnar AOD and BC AOD assuming the internal mixing state for the two future scenarios. Health benefits were analyzed in term of the avoided number of premature deaths associated with ambient PM2.5 reduction while the climate benefits were quantified using the reduction in the BC radiative forcing under RED2030. Under BAU2030, the average number of the premature deaths per 100,000 population in the domain would increase by 30 from BY2007 while under RED2030 the premature deaths would be cut-down (avoided) by 59 from the RED2030. In 2007, the maximum annual average BC radiative forcing in SEA countries was 0.98 W m which would increase to 2.0 W m under BAU2030 and 1.4 W m under RED2030. Substantial co-benefits on human health and BC climate forcing reduction in SEA could be resulted from the emission measures incorporated in RED2030. Future works should consider other benefits such as for the agricultural crop production, and the cost benefit analysis of the measures implementation to provide relevant information for policy making.