Emission trends and mitigation options for air pollutants in East Asia

Abstract

Emissions of air pollutants in East Asia play an important role in the regional and global atmospheric environment. In this study we evaluated the recent emission trends of sulfur dioxide (SO₂), nitrogen oxides (NO_x), particulate matters (PM), and non-methane volatile organic compounds (NMVOC) in East Asia, and projected their future emissions up to 2030 with six emission scenarios. The results will provide future emission projections for the modeling community of the model inter-comparison program for Asia (MICS-Asia). During 2005–2010, the emissions of SO₂ and PM_2.5 in East Asia decreased by 15 % and 11%, respectively, mainly attributable to the large scale deployment of FGD for China's power plants, and the promotion of high-efficient PM removal technologies in China's power plants and cement industry. During this period, the emissions of NO_x and NMVOC increased by 25% and 15%, driven by the rapid increase in the emissions from China owing to inadequate control strategies. In contrast, the NO_x and NMVOC emissions in East Asia except China decreased by 13–17% mainly due to the implementation of tight vehicle emission standards in Japan and South Korea. Under current legislation and current implementation status, NO_x, SO₂, and NMVOC emissions in East Asia are estimated to increase by about one quarter by 2030 from the 2010 levels, while PM_2.5 emissions are expected to decrease by 7%. Assuming enforcement of new energy-saving policies, emissions of NO_x, SO₂, PM_2.5 and NMVOC in East Asia are expected to decrease by 28%, 36%, 28%, and 15% respectively compared with the baseline case. The implementation of the "progressive" end-of-pipe control measures is expected to lead to another one third reduction of the baseline emissions of NO_x, and about one quarter reduction for SO₂, PM_2.5, and NMVOC. With the full implementation of maximum feasible reduction measures, the emissions of NO_x, SO₂, and PM_2.5 in East Asia are expected to account for only about one quarter and NMVOC for one third of the levels of the baseline projection. Compared with previous projections, this study projects larger reduction in NO_x and SO₂ emissions by considering aggressive govermental plans and standards scheduled to be implemented in the next decade, and quantifies the significant effects of detailed progressive control measures on NMVOC emissions up to 2030.