Another wheel has come off the great electric car con

Everyone wants clean air. But regulations which fixate on one form of pollution and ignore others ultimately help no-one

How lovely and clean London’s air will be once that nice Sadiq Khan’s Ultra Low Emissions Zone (Ulez) has been extended across the entire city and the Government’s ban on petrol and diesel cars has taken effect. Well, not quite. In fact, was there ever such a misnomer as a “zero emission vehicle”? Far from cleaning the air there is evidence that in one respect the adoption of electric vehicles could make pollution worse.

Electric vehicles might reduce carbon emissions (though far from eliminating them – indeed their manufacture involves carbon emissions). They might not have exhaust pipes spewing out nitrogen oxides. But growing attention has been paid in recent years to pollution from tiny particulate matter, which can penetrate deep into human lungs. Long-term exposure has been linked to an increased risk of heart disease and lung cancer. Trouble is that a fair amount of these emissions from cars emanate from tyres, not engines, and electric vehicles could possibly emit more because their heavier weight causes greater tyre wear.

While huge attention has been paid to emissions from exhausts, which quite rightly have been cleaned up over the years thanks to progressively tougher regulations, rather less attention has been paid to tyres. The Euro 4 regulations for petrol engines and Euro 6 regulations for diesel engines – on which Ulez is based – take little account of emissions from tyres; they are based on emissions from exhausts. Yet it doesn’t take too much to wonder if a heavy electric car driven around the streets of London could be emitting more tyre pollution than a relatively light petrol car.

Everyone wants clean air – and air pollution has fallen dramatically in many respects over the past half century. But regulations which fixate on one form of pollution and ignore others ultimately help no-one. We had a similar thing 20 years ago when the EU, along with the Blair government, offered tax incentives to encourage diesel engines on the grounds that, mile for mile, they spewed out less carbon dioxide. So they did, but they also emitted more nitrogen dioxides.

There is no point in employing measures like Ulez to drive petrol and diesel engines off the road unless legislation is also going to tackle pollution from tyres. There must be ways in which this form of pollution could be reduced, such as by tweaking the chemical composition of tyres – which use synthetic rubber manufactured from oil. Why can’t we have tax incentives for harder-wearing tyres, or for lighter vehicles? That would rapidly encourage car manufacturers to find ways of reducing tyre emissions.

The trouble is that this is not how green politics works. Rather it is in the hands of student-like activists who will obsess about one narrow objective to the exclusion of all other concerns. The promotion of electric cars is a case in point. Their cheerleaders have turned them into a pin-up for the green movement – while ignoring the carbon emissions from their manufacture, the consumption of heavy metals in the making of their batteries, and the filthy pollution from their tyres.