Is banning diesel vehicles the solution to bad air?

Mahindra & Mahindra has been at the receiving end of Supreme Courts proposal to ban registration of diesel vehicles over 2,000 cc in Delhi. Nearly 98% of the vehicles sold by the company is above the 2,000 cc category, but only 2% of sales of the company comes from Delhi.

Further, the ban is only till March 2016, but it is surely a sentiment dampener. Because of that, the stock is trading nearly 5% lower. Putting up a brave face, Anand Mahindra tweeted: “At the core of Mahindra’s DNA is the unshakeable belief that when the going gets tough, Mahindra gets going.”

However, three things need to be considered as far as banning diesel vehicles is concerned. First, what was the basis of the judgement? Second, does the same logic apply to other cities and can the ban be extended to other parts of the country? And third, is this the best solution?

Senior Advocate Harish Salve in his presentation to the court relied on IIT Kanpur’s draft report on air pollution in Delhi which revealed that diesel vehicles are a major source of particulate matter (PM) emissions in the transport sector. It showed how diesel vehicles contributed to 60-90% of PM 2.5 (particulate material which can be inhaled) emissions in some parts of Delhi.

But what is the source of PM 2.5?

According to the report, major sources of PM 2.5 in winter are vehicles and biomass burning while in summer, it's the road dust, coal or fly ash. On an average for the year, PM 2.5 emissions are on account of road dust (38%) and vehicles (20%).

Now, the question arises: is PM 2.5 the only source of pollution?

No, there are others like carbon dioxide, nitrogen (NOx) and sulphur (SOx). While SOx emissions were not discussed, NOx emissions are caused by industry stacks (52%) and vehicles (36%).

The report also pointed out that Delhi has witnessed a 97% jump in vehicles since 2,000 with nearly 8.5 million vehicles registered in the capital. But there are more two-wheelers in Delhi than cars.

According to environmentalists, 55 lakh two-wheelers are the biggest contributor to national capital’s vehicular pollution. Though two-wheelers which are generally petrol driven, have stricter pollution control norm, the sheer size of their numbers adds to the pollution.

Further, the number of diesel vehicles lesser than 2,000 cc is more than those that are higher as car makers over the years capitalised of diesel subsidy by the government.

What the data points out is that bad road conditions, which lead to high levels of road dust, are the highest contributor of pollution at 38% throughout the year, while the overall vehicle pollution is at 20%. Within the 20%, we have diesel vehicles, especially trucks and heavy vehicles that are considered to be the biggest contributor of pollutions.

Can the ban be extended to other parts of the country?

It too early to say, but Delhi, being a landlocked area which has seen very high levels of vehicular traffic growth, is among the most polluted cities in the world. Other metros are all on the coastline which gets some help from sea breeze clearing the air. Though there is no denying the fact that pollution levels in all cities have shot up.

So how can we control pollution? As the study pointed out, better road conditions can help in smooth movement of vehicles and reduce road dust. Secondly, better quality fuel from refineries and stricter emission norms needs to be imposed. We are still about five years behind emission norms that exist in developed countries. World-class public transport needs to be in place which should act as a deterrent for taking out personal vehicles. If we have a good public transport system, high parking cost and usage tax can be introduced to prohibit the use of personal vehicles.

While the Supreme Court ban might seem harsh on some automobile players, the message it sends across is that it is high time we acted on high levels of pollution, especially now that we have committed to reduce global warming.