Emission inventories of NO_x from commercial energy consumption in China, 1995 - 1998

Emissions of nitrogen oxides (NO_x) in China are of great concern because of their impact on local air pollution as well as on regional environmental risks such as acid rain, eutrophication, tropospheric ozone, fine particulate matter, and loss of biodiversity. In this paper, total anthropogenic emissions of NO_x in China during the past two decades are estimated on the basis of commercial energy consumption and NO_x emission factors of different sectors and fuel types. Specifically, emission inventories of NO_x from 31 provinces, 7 economic sectors, and 11 fuel types from 1995 to 1998 are evaluated and analyzed in detail, and the distribution of provincial-based average NO_x emission intensity in 1998 is presented. It can be seen that the calculated national total emissions of NO_x have rapidly increased from 4.76 Mt in 1980 to a peak value of about 12.03 Mt in 1996, with an average annual growth rate of 6%. However, instead of increasing, NO_x emissions in 1997 and 1998 decreased by 0.37 Mt and 0.85 Mt, respectively, as compared to the peakin 1996. In short, NO_x emissions caused by energy use are mainly concentrated in the more populated and industrialized areas of China, i.e., the Eastern Central and Southeastern areas. These results imply that China's NO_x emissions in the future may not become as high as previously expected which will be helpful for policy making to control local NO_x pollution as well as to reduce acid rain and tropospheric ozone in East Asia.