The order came after complaints of non-implementation of NGT’s order of April 2015, wherein it had banned diesel vehicles that were over 10 years old from plying on the roads of Delhi and the National Capital Region (NCR).

A bench headed by NGT chairperson Swatanter Kumar directed Delhi’s regional transport offices (RTOs) to give a list of deregistered vehicles to the city traffic police which, in turn, would act against them under the provisions of the Motor Vehicles Act.

“We are of the considered view that there is no occasion for the tribunal to set aside the April 7, 2015 order which prohibited plying of diesel vehicles which are more than 10 years old on the roads in Delhi-NCR... we hereby direct RTO Delhi to deregister all diesel vehicles which are more than 10 years old,” said the bench.

Stating that it is an accepted fact the world over that diesel vehicle emissions are more injurious to the environment than those from petrol and compressed natural gas (CNG) vehicles, the tribunal said its April 2015 ruling needs to be enforced rigorously.

The bench said it had been told that the traffic police had tried to stop old diesel vehicles from plying, but its efforts had met with little success because the vehicles that were fined or impounded managed to return to the roads.

The tribunal asked RTOs and the Delhi traffic police to issue public notices of its order.

As of 2014, Delhi had 89 lakh registered passenger vehicles. Of these, there are around 2.2 lakh diesel passenger vehicles and 1.7 lakh commercial vehicles that are over 10 years old, according to industry estimates.

According to an affidavit filed by the government before the Supreme Court in 2015, diesel-powered vehicles accounted for over 90% of sports utility vehicles in India, 34% of small cars and 70% of large and medium cars.

In November 2014, the NGT had ordered all vehicles that are more than 15 years old from plying on Delhi’s roads.

The NGT and the Supreme Court have in the past 18 months passed a series of orders to control air pollution in the NCR centredaround Delhi. For instance, the Supreme Court in December 2015 banned registration of diesel vehicles with engine capacity more than 2,000cc and made it mandatory for all diesel taxis plying in the national capital to convert to CNG.

The NGT bench also directed the central government to file an affidavit on the availability of electric and hybrid vehicles in India and the incentives the government proposes to offer buyers of such vehicles.

The bench asked the government how it proposes to increase manufacture of electric and hybrid buses and cars in India and what benefits it was considering for those who wish to dispose of their old vehicles.

The bench also took up the issue of noise pollution from vehicles in the capital and directed that “no vehicles of any kind” plying in Delhi will be permitted to use air pressure horns or horns not fixed by the manufacturer of the vehicles.

“Unthoughtful use of horns by car drivers, and particularly use of pressure horns by trucks and other heavy vehicles, are a source of serious noise pollution in Delhi. Even the sound of vehicles is a source of noise pollution, particularly the DTC (Delhi Transport Corp.) buses. All concerned authorities need to pay attention,” said justice Kumar.

“Even two-wheelers that are using pressure horns or who have removed silencers should not be permitted to ply on Delhi roads,” he added.

He asked the Union environment ministry to submit a detailed affidavit suggesting ways to curb noise pollution.

The bench also noted that it had previously issued orders to curb pollution from dust and burning of waste.

In 2015, NGT passed several directions to control air pollution from fuel emissions, construction sites, burning of waste and burning of agricultural residue.

Justice Kumar asked authorities such as the Central Pollution Control Board and the Delhi government to file a status report on implementation of these directions.

Environmentalists welcomed the order and said it is part of a larger strategy to control uncontrolled diesel emissions in the national capital.

“This order should not be seen in isolation but within the overall context of what is happening in the city to reduce emissions from vehicles. While the Supreme Court is now looking at controls on new diesel cars, NGT is looking at handling on-road vehicles,” said AnumitaRoychowdhury, executive director at Delhi-based environment think tank Centre for Science and Environment.

“So far, the city has already controlled diesel emissions from taxis, buses and has also imposed stringent action on diesel trucks entering Delhi. Even small commercial vehicles have been moved out of diesel. All this should now not be negated by uncontrolled dieselization of the personal segment. It is part of a larger strategy to reduce diesel emissions in the city. It is too important from the public perspective,” she added.

The auto lobby group Society of Indian Automobile Manufacturers said it has not seen the order yet and hence would not comment.

“We need to see the details carefully. While the reason for wanting to ban polluting vehicles is easily understood, any change to existing laws that is immediate or in the short term would cause serious implementation problems. Going by the announcement, if a person bought a used 10-year-old diesel car yesterday, it can potentially be useless tomorrow, irrespective of what condition it is in. I would wait to see the details. The best scenario would be for the stakeholders to have time to plan a response to a new legislation. This applies to both manufacturers and users,” said Kumar Kandaswami, senior director, Deloitte Touche Tohmatsu India Pvt. Ltd.

On NGT focusing on electric vehicles, Sohinder Gill, who is director, corporate affairs, at the Society of Manufacturers of Electric Vehicles (SMEV), welcomed the step.

“The Society welcomes the step taken by the NGT. SMEV feels that the time has come for the government to take some firm steps like these in combating ever-increasing pollution levels. Something similar can easily be done in de-registering polluting petrol two-wheelers used in the e-commerce and food deliveries business, which will also greatly impact pollution levels,” said Gill.