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

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, PM_2.5 and PM₁₀. The monthly non-attainment rates for O₃ vary from 7 to 25% for May to November. The city average PM_2.5 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 PM_2.5 high violation months are from November to March. A CIP was developed for Guangzhou, which focused on PM_2.5. Based on the CIP, the emission amounts of NO_x, PM₁₀, PM_2.5 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 PM_2.5 and PM₁₀ goals successfully by 2025. The PM_2.5 annual average concentration would be reduced to 27 μg m⁻³ in 2025. However, such PM_2.5-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 PM_2.5 control strategies, especially PM_2.5 compliance under increased atmospheric oxidation, and for VOCs / NO_x reduction ratios need to be further investigated, in order to eventually achieve O₃–PM_2.5 co-improvement in this region or other cities.