Unless you’ve been enjoying a long holiday on Pluto for the past few months it won’t have escaped your attention that diesel-engined cars are not flavour of the month. They’ve been singled out as pariahs for their part in poisoning our air, and is it any wonder when you see old buses and high-mileage (or badly maintained) family hatchbacks spewing out clouds of noxious soot as they accelerate away from the lights?
For years, diesel cars were set to save the planet. They produce less CO2 than petrol-engined vehicles because diesel contains more energy than petrol. However, while CO2 emissions are lower, diesels produce far more particulates and it’s these that cause air quality problems – they get trapped in our lungs and cause breathing difficulties.
It’s this air quality issue that has led to lots of headlines about thousands of premature deaths each year. However, that number varies wildly and nobody knows what it is because we’re not talking about healthy people being struck down in their prime. Generally those who are dying are already very ill, and their deaths are being brought forward by as little as a few days. But nobody knows how many days; no wonder the figure is impossible to pinpoint.