Extreme Emission Reduction Requirements for China to Achieve World Health Organization Global Air Quality Guidelines

A big gap exists between current air quality in China and the World Health Organization (WHO) global air quality guidelines (AQG) released in 2021. Previous studies on air pollution control have focused on emission reduction demand in China but ignored the influence of transboundary pollution, which has been proven to have a significant impact on air quality in China. Here, we develop an emission-concentration response surface model coupled with transboundary pollution to quantify the emission reduction demand for China to achieve WHO AQG. China cannot achieve WHO AQG by its own emission reduction for high transboundary pollution of both PM2.5 and O3. Reducing transboundary pollution will loosen the reduction demand for NH3 and VOCs emissions in China. However, to meet 10 mu g center dot m-3 for PM2.5 and 60 mu g center dot m-3 for peak season O3, China still needs to reduce its emissions of SO2, NOx, NH3, VOCs, and primary PM2.5 by more than 95, 95, 76, 62, and 96% respectively, on the basis of 2015. We highlight that both extreme emission reduction in China and great efforts in addressing transboundary air pollution are crucial to reach WHO AQG.

Automated summary

There is a significant gap between China's current air quality and the global air quality guidelines (AQG) released by the World Health Organization (WHO) in 2021. Previous studies on air pollution control in China have overlooked the impact of transboundary pollution, which has been proven to have a significant influence on China's air quality. A new model developed in this study combines emission-concentration response surface and transboundary pollution to quantify the emission reduction necessary for China to achieve WHO AQG. The study emphasizes the need for both extreme emission reduction in China and concerted efforts to address transboundary air pollution in order to reach WHO AQG.