Long-Term Trends of Anthropogenic SO2, NOx, CO, and NMVOCs Emissions in China

Studies reporting the historical trends of SO2, NOx, CO, and nonmethane volatile organic compounds emissions in China using unified approaches and sources are limited. Here we established 66-year emission trends of these four species in China. Six primary anthropogenic sources were included, and we made a series of improvements to the few existing inventories based on detailed statistical data, recently published emission factors, and technology renewal to reduce the uncertainties. National SO2, NOx, CO, and nonmethane volatile organic compounds emissions in 2015 were 27.1, 20.6, 188, and 28.4Mt, with annual growth rates of 5.8%, 5.9%, 3.8%, and 4.6% since 1949, respectively. In recent years, fossil fuel combustion was the major contributor to SO2, NOx, and CO emissions, whereas industrial process contributed most to VOCs emissions. Our results revealed a 10% decrease in the SO2 emissions from 2005 to 2010 as a result of improvements in the flue gas desulfurization installation rate. NOx emissions stopped rising and started falling in 2011, with technology renewal and the penetration of end-of-pipe control measures in industrial boilers and cement production. Furthermore, we calculated future speciated VOCs emissions and ozone formation potential under alternative policy scenarios and projected to reduce emissions by 10% (compared with 2013 levels) with stringent control measures in 2020. A reactivity-based control strategy was proposed to achieve greater ozone formation potential reductions while requiring less VOCs emissions reduction.