Declining short-term emission control opportunity for major events in Chinese cities

In China, short-term emission controls have been implemented widely in the host and nearby cities of major events to reduce air pollution. However, insufficient analysis of their effectiveness has weakened the design of pollution controls. In this study, we analyzed the impact of short-term controls on nitrogen oxide emissions and quantified their main drivers in both the host and neighboring cities of 11 events held in east China from 2010 to 2023. We found that short-term controls might be more effective in neighboring cities than in host cities for some events, and that their benefits in terms of reduced emissions have weakened over time. Furthermore, the main sector of emission abatement for events has shifted from power to industry and transportation, reflecting the evolution of emission controls and the relative dominance of air-pollution budgets for different sectors. Our analysis highlights the enhanced targeting of short-term air pollution controls for Chinese cities, which also supports the long-term policy design. For major events in China, such as the Olympic Games, air-pollution emission controls have been imposed in the host and neighboring cities to enhance the experience and reduce health risks. This study reveals the varying effectiveness of short-term emission controls between host and neighboring cities, showing weakening benefits over time as cities learned from past event-hosting experiences.