The particles produced by diesel engines are killing 7000 Britons a year. Experts want diesel engined cars banned from cities. But talk to enough people and you’ll find an argument to justify almost anything.
Professor Frank Kelly, chairman of the Department of Health’s committee on air pollution, claims 29,000 deaths a year in Britain are linked to poor air quality. Of those, 25 per cent are attributed to diesel emissions, hence that 7000 figure.
Yet Dr Lesley Walker, director of information at Cancer Research UK, counters: “The overall number of lung cancers caused by diesel fumes is likely to be a fraction of those caused by smoking tobacco.” A Government spokesman added: “No one type of transport is the sole cause of air pollution and there is no single magic bullet to tackle it.”
Taking Professor Kelly’s claim in isolation, by his own admission, 75 per cent of air pollution-related deaths are caused by factors other than diesel emissions.
According to the Society of Motor Manufacturers and Traders (SMMT) in 2014, 40.7 per cent of carbon dioxide (the main climate change gas) came from energy production. Industry produced 15.5 per cent. Commercial vehicles and other road transport (buses, taxis etc.) produced 9.3 per cent and cars kicked out 13.4 per cent.
Interestingly, the ‘commercial and other road transport’ category’s CO2 production comes from far fewer vehicles than cars’ share: only 12 per cent of the 31.5m vehicles on the road fall into that group. Let’s assume that many of this category of vehicles also have large thirsty, smoky diesel engines and you have another good reason why picking purely on cars isn’t the answer.
Since 2004, average carbon dioxide emissions in new cars have been cut by a quarter through relentless and costly development in the car industry. This reduction in CO2 is partly down to the popularity of diesel cars – 49.8 per cent of all cars sold in the UK last year were diesel.
With taxes benefiting diesel engines, the car industry has been working hard to tackle the particles and nitrogen oxides in them. Keith Lewis from the SMMT said: “Vehicle manufacturers work tirelessly, and have invested over £1 billion, to reduce and eliminate emissions from diesel engines. Vehicles being produced today feature filters that capture over 99% of particulates, resulting in engines that are the cleanest ever produced.”
Air quality expert professor Roy Harrison from Birmingham University said: “If you could replace older diesel engines with newer ones there would be benefits to our health. Manufacturers have found ways to overcome the particle problem. Whether that would create a nitrogen dioxide problem is less clear.” But replacing millions of otherwise perfectly roadworthy cars is another issue altogether.