THE majority of the people who think air pollution in Southampton is not a problem live out of the city centre and drive to work in the city or outskirts thereof. They come to the city centre to shop or attend events at the weekend in their car, and complain about the parking and traffic, stating that if the traffic flowed better, pollution would be reduced.

People who live in the city centre take public transport or ride to work and are more susceptible to air pollution from road traffic. They breathe in the heightened air pollution every day. Whether a car is moving or stationary makes little difference to pollution levels. It is about the number of cars. When roads flow well, more cars use the roads and pollution increases. When roads are congested, pollution also rises.

The only way to reduce air pollution is to reduce the number of diesel cars on the roads. Diesel cars produce far more pollutants than a petrol car of the same power-to-weight ratio. Diesel owners will come up with many excuses to argue how they are better for the environment, CO2 speaking, but in reality, diesel is only better for their wallets in terms of mileage. At the end of the day, we all understand the chemistry of combustion and that diesel cars produce far more NOx, SOx and particulate matter than petrol cars. We also understand that no catalytic converter, air scrubber or tree planting initiative will reduce the air pollution from diesels. Once it is made, it stays with us.

The only way to reduce pollution and save our health is to reduce the number of diesel cars on our roads. Incentives for electric cars need to be increased, with significantly lower purchase price and ongoing registration tax. E-vehicles are the future and we need to embrace their local manufacture, uptake on our roads and recycling of batteries, as is now happening in Japan. Otherwise we will be left behind yet again, from economical, technological and social health points of view.

Sam Parry