The toxic clouds that descended on China this month are a stark reminder of the high costs of unfettered development. Last weekend air pollution in Beijing was at its worst level since readings began four years ago. On Tuesday, in Zhejiang province, the smog was so thick that a factory fire went unnoticed for three hours. The smog did not stop at China’s borders: South Korea also recorded dangerous levels of air pollution.

Unusual weather patterns may have intensified the hazardous fumes. Yet the root causes lie elsewhere. Widespread burning of coal and soaring car emissions are the noxious consequence of China’s economic miracle. The government, moreover, has a poor record in implementing its environmental laws.

Of course, the western world has also had its toxic decades. During the industrial revolution, Edinburgh’s nickname “Auld Reekie” was amply justified. London was labelled “The Big Smoke” and its citizens regularly struggled through fogs called “peasoupers”, for their greenish colour. The darkest days of recent memory came in 1952, when the Great Smog of London resulted in 12,000 deaths.