A recent surge in the rate of global warming has been largely driven by China’s efforts to reduce air pollution, raising questions about how air pollution regulations are influencing the climate and whether we fully understand the impact of removing aerosols from the atmosphere. This extra warming, which was being masked by the aerosols, accounts for 5 per cent of the global temperature increase since 1850.

In the early 2000s China had extremely poor air quality as a result of rapid industrialisation, leading to a public outcry in the…