Assessment of air quality improvement effect under the National Total Emission Control Program during the Twelfth National Five-Year Plan in China

Abstract

The National Total Emission Control (NTEC) Program will continue to be implemented during the 12th Five-Year Plan period (FYP, 2011–2015) in China. Two pollutants (SO2 and NOx) are covered by NTEC, of which NOx is a newly added pollutant under control. NTEC requires that the national total SO2 and NOx emissions be reduced by 8% and 10% respectively in 2015 from the levels of 2010. Annual mean SO2, NO2, and PM2.5 (sulfates and nitrates) concentrations in 2010 and 2015 were simulated with the Community Multiscale Air Quality (CMAQ) model based on the national source census data and reduction targets in the NTEC Program. Reliability of the simulation results was verified by ground-based observation data and satellite remote sensing data in 113 national key monitoring cities. The air quality improvement from NTEC was also assessed quantitatively. The assessment results indicated that the average SO2 and NO2 concentrations in all cities in 2015 would be reduced by 9.28% and 10.61% respectively from the 2010 levels. The number of cities whose annual average SO2 and NO2 concentrations fail to comply with the national ambient air quality standard will be reduced by 9 and 27 respectively. The PM2.5 simulation results demonstrated that the average sulfate and nitrate concentrations in all cities in 2010 accounted for 20.28% and 17.45% of the PM2.5 respectively. Having considered the emissions reduction effect of SO2 and NOx only, the average sulfate, nitrate, and PM2.5 concentrations in all cities in 2015 will be reduced by 6.25%, 6.04%, and 2.23% respectively from the levels of 2010. However, the annual mean PM2.5 concentration will still exceed the national standard in 77.18% of the cities in China in 2015. These percentages would be as high as 99.70% based on U.S. national standards and 100% based on the World Health Organization's guideline value.