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

Emissions of nitrogen oxides (NOx) 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 NOx in China during the past two decades are estimated on the basis of commercial energy consumption and NOx emission factors of different sectors and fuel types. Specifically, emission inventories of NOx 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 NOx emission intensity in 1998 is presented. It can be seen that the calculated national total emissions of NOx 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, NOx emissions in 1997 and 1998 decreased by 0.37 Mt and 0.85 Mt, respectively, as compared to the peak in 1996. In short, NOx 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 NOx emissions in the future may not become as high as previously expected which will be helpful for policy making to control local NOx pollution as well as to reduce acid rain and tropospheric ozone in East Asia.