Air Pollution Regulation for Sustainable Development in China: A BERTopic Analysis of 12,081 Policies

Air pollution governance is crucial to China’s sustainable development, and the complexity of the low-carbon transition necessitates a systematic assessment of the evolving policy landscape. This study constructs a large-scale corpus of air pollution environmental regulation documents issued by the central government and 31 provincial-level governments, collected through large-scale web crawling from official government portals. This study utilizes the BERTopic model to extract policy topics and systematically analyze policies through topic content, topic hierarchy, topic similarity, and clustering structure, as well as dynamic topic evolution over time. Key findings are as follows: (1) The BERTopic results identify 31 policy topics, and Topic 0–Topic 11 collectively account for 82.8% of all documents. (2) The topics mainly focus on three areas: comprehensive air pollution control and enforcement, structural low-carbon and energy transition, and governance capacity building through monitoring, fiscal incentives, and carbon accounting. (3) Hierarchical and similarity analyses indicate three relatively stable core thematic groups, alongside two specialized peripheral themes. (4) Over the study period, dynamic topic trends show a shift in policy emphasis from air quality-oriented control toward low-carbon transition and supporting policy instruments. These findings clarify the thematic structure and evolution of China’s environmental policies, offering an evidence base for improving integrated air pollution governance toward sustainable development.