THE debate on whether the Supreme Court is poaching new territory will carry on but judicial intervention in the face of executive lethargy is welcome if it means cleaner air. I just spent 10 days in Delhi catching up with old friends and I felt the air was cleaner, crisper and the pollution seemed significantly lower. It is an impressionistic view but impressions count for something if you have been a frequent visitor over the past two years, faithfully invading friends every three months or so. With every trip I noticed the air getting better as CNG vehicles increased on the roads. This winter the family complained less about sore throats and the cousins' noses were drier. Should we be grateful to that thin green line painted on buses and the natty, new scooties? I think so. No mushroom clouds bursting out of leaking exhaust pipes, no acrid smell from that special mixture of kerosene and petrol which scooterwallahs concocted to reduce cost. This time even my neighbourhood cabstand had fully converted its local fleet to new Maruti taxis, clean and green. Big Boss Sardarji, who always gives me excellent service, whined on about the long lines to fill up CNG but deep down harboured no real resentment. "Haur dasso ji, behn ji," he said genially. Is CNG the best option? Environmental arcana aside, the debate has just begun—typically not when the court gave its order but after the deadline was past.