Feasibility and difficulties of China's new air quality standard compliance: PRD case of PM_2.5 and ozone from 2010 to 2025

Abstract

Abstract. Improving the air quality in China is a long and arduous task. Although China has made very aggressive plans for air pollutant control, the difficulties in achieving the new air quality goals are still significant. A lot of cities are developing their implementation plan (CIP) for new air quality goals. In this study, a southern city, Guangzhou, has been selected to analyze the feasibility and difficulties of new air quality standard compliance, as well as the CIP evaluation. A comprehensive study of the air quality status in Guangzhou and the surrounding area was conducted using 22 monitoring sites collection data for O3, PM2.5 and PM10. The monthly non-attainment rates for O3 vary from 7 to 25% for May to November. The city average PM2.5 concentration was 53 μg m−3 in Guangzhou in 2010, which needs to be reduced by at least 34% to achieve the target of 35 μg m−3. The PM2.5 high violation months are from November to March. A CIP was developed for Guangzhou, which focused on PM2.5. Based on the CIP, the emission amounts of NOx, PM10, PM2.5 and volatile organic compounds (VOCs) in 2025 would be controlled to 119, 61, 26 and 163 thousand tons, respectively, reduced by 51.9%, 55.9%, 61.8% and 41.3%, respectively, compared to 2010. Analysis of air quality using the model MM5-STEM suggests that the long-term control measures would achieve the PM2.5 and PM10 goals successfully by 2025. The PM2.5 annual average concentration would be reduced to 27 μg m−3 in 2025. However, such PM2.5-based emission control scenarios may enhance the ozone pollution problems. The O3 non-attainment rate would increase from 7.1% in 2010 to 12.9% in 2025, implying that ozone will likely become a major compliance issue with the new national ambient air quality standards (NAAQS). This suggests that O3 control must be taken into account while designing PM2.5 control strategies, especially PM2.5 compliance under increased atmospheric oxidation, and for VOCs / NOx reduction ratios need to be further investigated, in order to eventually achieve O3–PM2.5 co-improvement in this region or other cities.