Shutting all the major coal power plants in the city, equivalent to reducing annual coal use by 9.2 million metric tonnes, is estimated to cut carbon emissions of about 30 million tones, said Tian Miao, a Beijing-based analyst at North Square Blue Oak Ltd, a London-based research company with a focus on China. “Most pollutants come from burning coal, so the closure will have a clear impact to reduce emissions,” Mr Tiansaid. “The replacement with natural gas will be much cleaner with less pollution, though with a bit higher cost.”