Cities should become low-carbon zones

European Mobility Week encourages cities to improve air quality – with good reason. Vehicle emissions kill more people than pollution from any other source.

Humanity’s mass migration to cities is generally seen as something positive. It’s a way of escaping grinding rural poverty, of gaining access to education, of expanding one’s horizons, of generally improving the human condition. But whatever advantages cities have over the countryside, clean air is not one of them. To highlight the problem, European Mobility Week has chosen air quality as its focus for 2013.

The problem is most visible in the cities of the emerging world, where the fumes from automobiles blend together with smoke from polluting factories to create a near permanent haze. In notoriously polluted China, air pollution is estimated to cause hundreds of thousands of premature deaths each year.

Premature deaths
The skies may be less hazy in developed countries, but it’s becoming increasingly clear that the air quality is not much better. After tracking emissions from various sources, MIT researchers have concluded that 200,000 people in the United States die prematurely each year from inhaling polluted air and the most deadly source of emissions is road transportation, accounting for 53,000 early deaths.

The reason vehicles have such a big impact, says MIT, is because they “tend to travel in populated areas, increasing large populations’ pollution exposure”. Emissions from power plants, by contrast, may be more harmful to human health but they cause fewer deaths because they are located far from most population centers.

To date, measures to curb vehicle use in cities have tended to get short shrift from drivers – and therefore from politicians – but experience shows that restrictions and incentives, intelligently applied, do make a difference.

Congestion charge
The best-known example is London’s congestion charge, introduced ten years ago. At the time, opponents said it was doomed to fail, but anyone who spent time in London before 2003 cannot fail to see – and smell – the difference today. Singapore, which introduced a congestion charge in 1975, has long enjoyed a reputation as one of Asia’s least congested and polluted metropolises. Other strategies, such as restricting cars with certain number plates on certain days, have prevented Mexico City and São Paulo from grinding to a halt.

The problem with these measures is that they are roughly equivalent to reducing the number of smokers in a room. They free up some space by reducing congestion, and the level of harmful toxins in the air may drop, but the room is still full of smoke. The only way to clear the air is to prohibit smoking altogether.

Until now, the idea of banning CO2-emitting vehicles from cities was pipe dream because there was simply no alternative to petrol and diesel engines. But with electric vehicles coming of age, low-carbon cities are becoming a distinct possibility. The obstacles remain huge, of course, but increasingly they are political rather than practical or technological. And as the link between vehicle emissions, respiratory illnesses and premature deaths becomes too difficult to ignore, so the social pressure for change is likely to drive policy.

After all, there’s not much point in moving to the city in search of a better life, only to have your health ruined once you get there.