Breathe easy People's Car, Nano, not that polluting

In spite of what Ratan Tata might say, Sunita Narain and RK Pachauri would have spent an uneasy night. The prospect of hundreds and thousands of Nanos trundling down the roads of various Indian cities spewing carbon dioxide and nitrous oxide would have been nightmarish for them.

Are their worries justified? Not really, if the evidence and maths are taken into consideration. But that is getting ahead of the story.

For some experts, Tata Nano is actually a good thing. After all, had the Tata Nano not come along, there would have been another car to take its place.

"India is a growing economy and so people will buy cars. It is a good thing that they will perhaps be buying a smaller car which is complying with more stringent norms rather than a much larger car or a two-wheeler that follows less stringent norms," says Krish Krishnan, managing director, Green Ventures, a venture fund that invests in green initiatives. Mr Krishnan has been an entrepreneur in sustainable environment development.

But let us get to the heart of the argument and look at it clinically. After all, how much pollution will the Nano cause? Automobiles produce many pollutants: carbon monoxide, unburnt hydrocarbons and nitrous oxides. To make things simple, all of these have to be converted into equivalent amounts of carbon dioxide (CO2) — the Mr Evil of environment today.

Now Euro IV compliant cars, which the Tata Nano is, produce one (1) gramme of carbon monoxide and 0.08 gramme of nitrous oxide. To convert them into CO2 equivalent, a conversion factor recommended by IPCC (Intergovernmental Panel on Climate Change) of which Mr Pachauri is chairman, is applied. It is 3 for carbon monoxide and 310 for nitrous oxide. Once all the maths is done, we get 30 grammes per kilometre.

So each time the Tata Nano moves a kilometre, it will release 30 grammes of CO2 equivalent material into the atmosphere. This is 40% less than what all others cars produce (50 grammes/kilometre or more) — and there are more than 5 million cars in India today. But let us take the argument into a zone where the naysayers would be comfortable: on the total amount of CO2 equivalent that Tata Nanos will produce over the next five years. This involves a bit of some assumptions.

So assume that Tata will from the next year sell 1,00,000 cars a year for five years and reach a total of 5,00,000 - half the size Mr Tata thinks a car at one-lakh price point may sell. Now let us take a range that the Tata Nano runs between 1,000 kilometres and 8,000 kilometres a year. If all those half-a-million cars run 1,000 kilometres then the total CO2 produced will be 15,000 tonnes annually.

If they all run 8,000 kilometres then the total CO2 equivalent will be 1,20,000 tonnes. In reality, the figure should be closer to 25-30,000 tonnes because our assumptions of car sales and annual mileage are on the higher side.

So are these numbers large? Taking the worst case - 5,00,000 on roads and each running 8,000 kilometres annually - the total CO2 equivalent will be less than 8% of India's total CO2 emission. And if we take a more realistic assumption then it will be less than 1% of India's total CO2 emission. Environment guys would do well to go after the other 99%.