We all know that big-engined gas-guzzlers are wrecking the planet and need to be driven off the road. Instead, we should all be using clean-green public transport for local journeys.   

The term ‘clean’ has become synonymous with super-frugal, low-CO2, cars but it is deeply-flawed terminology. CO2 may well be one of a number of ‘greenhouse’ gases, but in terms of an immediate threat to human health, it is the byproducts of diesel combustion that are the real problem.   

I cannot understand why there wasn’t a uproar when, a few months ago, the World Health Organisation declared that diesel engine exhaust fumes can cause cancer in humans. Incredibly, the WHO placed diesel engine exhausts gases in the same category as asbestos, arsenic and mustard gas.   

Of course, we’ve all seen the clouds of black soot emitted by diesel vehicles when the driver accelerates hard. The particular problem are the tiny particulates that get lodged in the lungs and are suspected of being a trigger for cancer and possibly other diseases such as a Sarcoidosis. What you can’t see coming out of the exhaust are the Nitrogen Oxides, which are a big component of smog and a first-class lung irritant.  

I suspect that the silence from the normally noisy environmentalists is because much of the problem in towns and cities is caused by public transport and commercial vehicles. I can’t help but think that the amount of venom directed at, say, Range Rovers is simply displacement activity on the part of campaigners who, deep down, know where the real threat to health lies.