India’s Supreme Court ordered on 26 March that all of the 12,000 buses currently on the roads and thousands of three-wheeled rickshaws must be converted to CNG by 30 September. The court’s earlier deadline for the rule was 31 March, but bus companies and the Delhi Government, which first proposed the rule, argued that they could not convert all of their vehicles or buy new ones in time.

Instead, operators will only be allowed to run their buses if they produce proof by 1 April of their intent to switch to CNG, by displaying a sticker signed by Delhi’s transport minister on the windscreen, and only vehicles less than eight years old will be permitted on the roads. As a further restriction, operators will only be able to use the same number of buses as the number of CNG vehicles they have ordered.

The government of this megalopolis of some 14 million inhabitants proposed the law to cut vehicular pollution, which it says accounts for about two-thirds of the air pollution in Delhi and, in 1998-9, emitted an estimated 666,000 tonnes of pollutants annually. CNG, a mixture of hydrocarbons consisting of approximately 80 to 90% methane in gaseous form, is estimated to have a cancer potency 80 times less than Indian diesel vehicles and one CNG bus achieves emissions reductions equivalent to removing 85-94 cars from the road. There are now 80 CNG filling stations in New Delhi.

Refusing to give any blanket extension of the March 31 deadline, the Supreme Court said its relaxation was being given “in public interest and with a view to mitigate the sufferings of the commuter public in general and the school children in particular”. The state government had pleaded that if an extension was not given to the deadline, “urban chaos” would ensue.

The Centre for Science and Environment (CSE), one of India’s leading environmental NGOs, welcomed the Supreme Court verdict and that the extension of the deadline for conversion of buses to CNG should come with the personal accountability of the Delhi government.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie