Delhi is smothered in a blanket of thick smog. Fierce dust storms in the Middle East have blown across the subcontinent, exacerbating the usual pollution. With a population the size of Australia occupying greater Delhi, the traffic is chaotic. The drive from the new Indira Gandhi international airport is like an interminable dodgem car ride with the incessant horns serving as an informal sonar system, warning drivers and riders that the slightest opening in the tangled wall of traffic is about to be occupied by another vehicle.