BBC Science Focus

CAN ELECTRIC CARS SAVE OUR CITIES?

As Volvo announces plans to go all-electric by 2019, transport expert Ian Walker weighs up the environmen­tal pros and cons

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Volvo is the first major car company to announce that all its cars will soon have electric motors. None of its new models will rely solely on internal combustion after 2019, and other manufactur­ers are presumably not far behind. So what does this mean for the environmen­t, and for our congested cities? Are electric cars really as eco-friendly as we’re led to believe?

There is one area where electrific­ation clearly brings an advantage, and that is exhaust emissions. Fumes from vehicles are implicated in around 40,000 premature UK deaths every year, with around 9,000 in London alone. Diesel fumes are a major issue here, although petrol is hardly benign. Vehicle emissions cause a host of unpleasant conditions, including cancer, heart disease, diabetes and Alzheimer’s. Shifting to electric vehicles has the potential to change this dramatical­ly, especially in urban areas.

There is also the possibilit­y that electric cars, in the long term, might introduce a virtuous cycle of energy efficiency. Electric motors are not as heavy as their oil-powered ancestors, which means the overall vehicle can be lighter. In a country where most vehicles have become lighter, the damage from impacts is reduced. This means cars need less protective armour, which makes them even lighter, so they need even less energy to get around, which further reduces their damage, and so on…

Finally, there is the possibilit­y of reduced carbon emissions, although this one is a bit less clear-cut. The carbon cost of electricit­y entirely depends on how it’s generated. I’m writing this on an overcast, still day, and right now 49.4 per cent of UK electricit­y is from burning gas. Charging a car now would be far less green than charging it when it’s sunny or windy. The greenness of electric vehicles, then, depends either on people’s willingnes­s to hold off charging them until conditions are good (which, based on some of our research at the University of Bath, looks unlikely) or a breakthrou­gh in battery technology that allows energy to be stored efficientl­y from good days to bad days.

“GOING ELECTRIC WOULD DO NOTHING TO REDUCE CONGESTION”

Given their potential advantages – and the lack of urban pollution is one that’s particular­ly appealing – it would be easy to become highly enthusiast­ic about electric cars. Many people already have. Government­s might even be tempted to subsidise them to encourage a rapid uptake. But before we rush headlong into an electric future, it’s important to consider any possible downsides too.

The main issue is that cars – both by their intrinsic design and by the way we use them – are associated with a broad range of problems that, at best, will be untouched by taking out a combustion engine and replacing it with an electric motor. Going electric would do nothing to reduce congestion – indeed, it could plausibly make it worse if pollutionl­ess driving starts to feel ‘guilt-free’. Electrific­ation also fails to address the issue of where we store cars when they’re not being used – and when you think about it, that’s almost all the time.

There’s also a host of issues that electrific­ation, at best, addresses to such a marginal degree that it’s hardly worth the bother. Take noise pollution. This is a far bigger public health problem than you would believe, contributi­ng to conditions like hypertensi­on, sleep disorders, and behavioura­l problems in children. But above even modest speeds, the noise from cars is mostly from the tyres, not the engine. Research we’ve carried out at Bath, with colleagues from Trinity College Dublin, showed that even if vehicles went 100 per cent electric overnight, the noise issue would be only very slightly reduced. Hardly a ringing endorsemen­t.

But perhaps the greatest public health issue of our age is one that electrific­ation completely fails to address: physical inactivity. The way we build and run our towns and cities means that it’s easy, and socially acceptable, to drive short distances. At least a quarter of English car journeys are under two miles, usually taking up precious road space by carrying around several empty seats. These are journeys that in most cases would be quicker, cheaper and a great deal healthier and less congesting if walked or cycled. The guilt-free nature of electric cars could even make this slightly worse.

There are certainly advantages to a change like Volvo’s, particular­ly when it comes to reducing urban pollution. But all we are being offered at the moment is the chance to replace cars’ engines, not to look at the way we use cars in society. This means that we fail to work towards towns and cities that are truly healthier, safer and more welcoming, and we fail to free rural communitie­s from their car dependence. There’s a sense in which electric cars are old milk in new bottles. Really we should be asking far more fundamenta­l questions about how and why we travel rather than just what sort of engines our cars have.

Dr Ian Walker is a psychologi­st at the University of Bath who specialise­s in traffic safety, transport choices and energy consumptio­n.

 ??  ?? Head of Volvo Hakan Samuelsson at the announceme­nt
Head of Volvo Hakan Samuelsson at the announceme­nt
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