Smog is a major problem in Chinese urban centers. In this interview by Latest Thinking, Dr. Anna L. Ahlers explores how the Chinese authorities go about removing air pollution from cities in advance of prestigious international events. Focusing on actions taken in relation to the 2016 G20 summit in Hangzhou, Ahlers and her colleagues carry out interviews with scientists and local government officials, triangulating their responses with a range of other data sources. Identifying a high level of collaboration between scientists and local authorities, Ahlers notes that many of the environmental measures introduced for the G20 were designed to have lasting impact. Beyond its focus on environmental policy, the research offers important insights into the workings of Chinese local government and the role that scientific information plays in policy formulation in China.