In 2013, Beijing declared war on pollution. Not a campaign or a slogan, but a trillion-dollar mobilisation. The city shut 3,000 coal boilers, slashed coal use by 30%, and forced factories to comply or close. Clean energy replaced soot. Electric buses replaced diesel fleets. The subway expanded to 1,000 kilometres. By 2020, 40% of new car sales will be electric. Delhi shares a few pollution source similarities with Beijing, notably coal use and vehicular emissions, but also faces unique challenge