Anthropogenic Emissions of SO2, NOx, and NH3 in China

Abstract

Since 2010 China has contributed approximately 30% of SO2, 24% of NOx, and 20% of NH3 global anthropogenic emissions, which has caused severe air pollution and led to adverse impacts on human health and ecosystems. Reliable emission estimation for SO2, NOx, and NH3 from anthropogenic sources is essential for both understanding the sources of air pollution and designing effective air pollution control measures. In this chapter, long-term anthropogenic emissions of SO2, NOx, and NH3 in China, their driving forces, and underlying uncertainties are analyzed systematically. Emissions of SO2 and NOx have significantly decreased as a consequence of stringent clean air policies implemented in China in recent years. National emissions of SO2 and NOx decreased by 62% and 17% during 2010–2017, respectively. Emission control measures are the main drivers of these reductions, among which pollution controls on power plants and industries are the most effective mitigation measures. The total NH3 emissions in China increased from 5.9 to 11.1 Tg from 1980 to 1996, driven by increasing demand for meat and enhanced crop yields, and then decreased to 9.7 Tg in 2012. The two major contributors were livestock manure and synthetic fertilizer application, which contributed 80–90% of total NH3 emissions. Emission estimates from various investigations are compared from bottom-up and top-down perspectives. Finally, we suggest future directions for accurate emission estimates and improved design of air pollution control policies in China.