Beijing’s Olympic shutdown begins on Sunday, a drastic plan to lift the Chinese capitals gray shroud of pollution just three weeks ahead of the games.

Half of Beijing’s 3.3 million vehicles will be pulled off the roads and many polluting factories will be shut.

Chemical plants, power stations and foundries left open have to cut emissions by 30% – and dust-spewing construction in the capital will be halted.

In a highly stage-managed Olympics aimed at showing off the rising power of the 21st century, no challenge is greater than producing crystalline air for 10,500 of the world’s greatest athletes.