Over 24,000 taxis, of the 40,000-odd plying on city roads, have to be phased out by March 31, 2009.

Around 8,400 public and private buses, of over 14,000, will have to be taken off the road by March 2009.

Over 80,000 autorickshaws, including unregistered ones, in and around Calcutta will either have to be scrapped or converted to cleaner fuel like LPG or CNG by December 2009.

The high court on Friday gave a fresh lease of life to the city’s ambient air by converting an environment department notification into an order.

“We think the government can no longer sit back and see the air quality of Calcutta deteriorate. The court order has made it mandatory for them to act in a time-bound manner,” said Subhash Dutta, who filed a petition in the high court in 2007 on rising vehicular pollution in the city.

During the hearing of Dutta’s petition on Friday, the division bench of chief justice S.S. Nijjar and Justice P.C. Ghosh gave its seal of approval to the environment department notification issued on Thursday..

“It was drawn up on the basis of orders of the Supreme Court and Bombay High Court, as well as various orders issued by the state transport department,” said Biswajit Mukherje, the chief law officer of the state environment department.

The Telegraph has been campaigning for over three years against the rising air pollution in Calcutta. A few months ago, scientists from the state pollution control board made a presentation to the transport and environment ministers on the “alarming air quality” of Calcutta, which is a health hazard for its residents.

Several studies have shown that automobile emission is responsible for around 60 per cent of the city’s air pollution.

“Air pollution could not be reduced as the transport department did not enforce emission norms properly and took no initiative to introduce cleaner fuel,” said auto emission expert S.M. Ghosh.

With the court making the environment department notification an order, the government will now have to phase out old vehicles.

It will also have to crack down on unauthorised autorickshaws, prevent adulteration of fuel and act against auto emission testing centres that issue fake pollution under control (PUC) certificates. The notification/court order also made it mandatory for the government to scrap two-stroke autos by December 2008.

Oil companies have been directed to ensure steady supply of cleaner fuel like LPG and CNG.

“We will implement the notification properly,” said state advocate general Balai Roy.