Cost-Effectiveness of NOX and VOC Co-operative Controls for PM2.5 and O3 Mitigation in the Context of China’s Carbon Neutrality

Co-operative controls of NOX and VOC are increasingly emphasized to mitigate both PM2.5 and O3 pollution in China. Given the substantial reductions in air pollutants expected under carbon neutrality, both PM2.5 and O3 concentrations will ultimately decrease to low levels regardless of co-operative controls. Therefore, understanding the cost-effectiveness of co-operative controls in the context of carbon neutrality is critical to enhance the feasibility of implementing relevant policies. Here we evaluate the control costs and health benefits under four co-operative control strategies. We show that adopting co-operative controls in megacity clusters can generate significant net benefits (health benefits minus control cost), such as Beijing-Tianjin-Hebei and its surroundings (net benefits: 0.23 trillion USD) and the Yangtze River Delta (net benefits: 0.12 trillion USD), while the merit of adopting co-operative controls nationwide is unnoticeable. Furthermore, these benefit increments induced by co-operative controls are not considerable compared to the benefits induced by carbon neutrality itself. The role of co-operative controls deserves reconsideration in alignment with carbon neutrality, with a focus on some specific regions rather than uniform implementation across all cities.