One of the many pleasant surprises for visitors to the Beijing Olympics was the quality of the air. Even days before the event started, the city was shrouded in a hazy, humid fog that reduced visibility to only a few hundred metres. Yet by the time the main athletics events began in mid-August, it was enjoying its best air quality in a decade, with blue skies and cool breezes.

The relief from the summer smog could be short-lived, however. Shortly after the paralympics end on September 17, the emergency restrictions on car-use and factories will be abandoned and Beijing residents will go back to suffering the downsides of the country’s economic boom.