鈥淯nlike finding a cure for cancer, we know how to tackle this problem because we鈥檝e done it before,鈥� says Michael Brauer of the University of British Columbia. 鈥淭he new laws introduced in the UK in the wake of 1952 [the pea-souper smog that killed 12,000 Londoners] and the way California has set standards to force industry to innovate and become cleaner point the way.鈥�
Still, solutions evade us. In the West, transport is the main cause for concern. Per capita car ownership roughly doubled between 1970 and 2012 in most of North America, western Europe, Australia and New Zealand. Cities have tried to keep cars off the road in several ways. Paris only allows vehicles with odd or even licence plate numbers on certain days. Freiberg in Germany has focused on providing cheap, efficient public transport. London and Stockholm have introduced congestion charges.
Read more: Cutting through the smog on air pollution
The bad news on bad air seems to get worse by the day, but all is not as it seems over Western cities. We take a look at the numbers
Evaluating these schemes is a challenge, because you would need to isolate their impact on pollution from other factors that might have also changed pollution levels. The best available evidence suggests many major efforts to reduce pollution from traffic have either failed or had little measurable effect. Some road space rationing schemes have had perverse knock-on effects. According to some reports, people in Mexico and Beijing have started buying second vehicles with different licence plates to get around restrictions. Often the second car will be cheap and more polluting.
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Charges or fines for taking larger, more polluting vehicles inside low-emission zones may be no better. There are more than 200 of these zones in Europe. But a 2015 evaluation of the London LEZ, the largest in the world, found it had no impact on levels of pollutants or related respiratory and allergy problems in children. The study authors speculated this was because of a delay in the introduction of tougher European standards for light goods vehicles and an increase in the proportion of diesel cars, encouraged by tax incentives. The results mirrored those in five Dutch cities, where LEZs had little effect on traffic-related pollution levels. A 2011 assessment of London鈥檚 congestion charge scheme also found no compelling evidence that pollution had fallen two years after it was introduced.
鈥淎 2011 assessment of London鈥檚 congestion charge scheme found no compelling evidence that pollution had fallen鈥�
Copenhagen and Amsterdam lead the world in getting their inhabitants to ditch their cars by providing better cycling infrastructure, but other governments are failing to put their money where their mouths are. The UK government last year announced ambitious plans to double cycling journeys by 2025, reverse the decline in walking, reduce cycling fatalities and increase the proportion of children walking to school. The 拢316 million it has dedicated to achieving these goals over five years in England outside London is dwarfed by the 拢15 billion budget for major road improvements over the same period.
In the end, outside highly centralised, authoritarian states, there is only so much governments can do. Individuals also need to realise the pollutants they breathe are produced when they drive short distances, fail to insulate their homes which would reduce heating bills, or buy intensively farmed meat, which produces a lot of NOx.
Figuring out what you can do to make the most impact will depend on where you live. A European Union funded project, ClairCity is customising pollution models to help individuals in various cities to identify behaviours that will have the maximum impact in these locations. 鈥淯ltimately, we control our own behaviour,鈥� says Gavin Shaddick of the University of Bath, UK. 鈥淭he tipping point will come when communities, societies and groups of people decide to do something about it.鈥�
This article appeared in print under the headline 鈥淐utting through the smog鈥�
