MILLIONS more people in London will wake on 25 October to find themselves living in a clean air zone, designed to deter the most polluting cars, motorbikes and vans and reduce the health effects of exposure to air pollution.
The expansion of the city’s Ultra Low Emission Zone (ULEZ) from the centre to the suburbs is a key part of mayor Sadiq Khan’s battle to rein in areas with levels of nitrogen dioxide in breach of legal limits. “It is going to be the biggest scheme of its type in the world,” says Shirley Rodrigues, London’s deputy mayor. “These are big interventions. What’s so powerful about them is they happen quickly and that they are sustainable interventions, not one-offs.”
Such zones are starting to yield important data on their impact. , which is about 18 times smaller than the new one, found that they fell at four times the rate of sites in outer London between February 2017 and February 2020.
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Gary Fuller at Imperial College London, who reviewed that analysis, says: “In terms of do low emissions zones work, there is a really strong evidence base that they do.” He says there is , too. German cities, for example, .
Such information suggests that there is no dramatic change in air quality on the day they take effect, says Fuller, because the shift is gradual. Simply announcing the start date of a zone usually triggers “pre-compliance”, in which people upgrade their cars to newer, cleaner ones years in advance. “The benefits start well before the charge starts,” says Fuller.
“Clean air zones drive down air pollution, but they need to come with support for people and businesses”
That is how low emissions zones, also known as clean air zones, are designed to work: as a catalyst for change rather than through people paying fees to keep polluting (£12.50 per day in London for most vehicles). Rodrigues says more than 80 per cent of cars in the area meet the London ULEZ’s emissions standards, which generally means diesels sold after 2015 and petrol models sold after 2005, and she expects that figure to rise.
Efforts to establish clean air zones in other pollution-soaked UK cities are lagging, though. “They’ve been far too delayed, far too slow,” says Jenny Bates at campaign group Friends of the Earth. After losing a legal challenge about progress on air quality, the UK government , a goal that hasn’t yet been met.
Too slow
Outside London, there are 21 local authorities in England that have either implemented or are planning nine clean air zones – several overlap more than one local authority – according to environmental law group ClientEarth. In March, Bath became the first English city outside London to implement a clean air zone, although it doesn’t cover cars and motorbikes, only larger vehicles. The country’s second biggest city, Birmingham, followed suit in June, but with a more ambitious scheme that covers all vehicles.
Andrea Lee at ClientEarth welcomes those schemes and others coming, such as one planned for Greater Manchester that she thinks will happen next year. However, she says, action is still slow. The UK government’s . Several cities , while some, such as Southampton and Derby, have rejected the idea and are trying different measures such as greening public transport or improving traffic management.
“We said from the start the way the government set this process up was passing the buck to local authorities,” says Lee. “We said it would lead to delays, and it has.” To date, no local authority has been sanctioned by central government for failing to introduce a clean air zone.
“The aspiration is zero carbon, zero pollution, so zero emissions zones are still being looked at”
Other parts of Europe are forging ahead with clean air zones. , as well as Brussels, Madrid and Paris. The focus is usually on reducing levels of NO2 and particulate matter a few micrometres across. However, there have been setbacks. Madrid’s zone started in 2018, and saw .
But , following a series of court cases.
One surprising success from the existing zones in Germany and central London is that they seem to reduce pollution in surrounding areas, rebutting criticism that such schemes displace polluting cars to elsewhere. “There’s no evidence that actually happens,” says Fuller. The positive spillover effect is probably explained by cleaner vehicles bought for use inside the zone being driven outside it too, he says.
Lee says the possibility of displacement is actually an argument for more clean air zones, rather than just a scattered handful. “That’s why the Greater Manchester local authorities are acting together,” she says.
Schemes have also been criticised for hitting the poorest in society hardest. Fuller says that doesn’t seem to be true: cars in the UK’s poorest areas are , so there is no reason poorer people would be disproportionately charged for using older cars. Lee says protecting people on lower incomes is one reason the zones can’t be the only policy in use: “Clean air zones are a key measure to drive down the illegal levels of air pollution, but we do think they need to be accompanied by support for people and businesses.”
Bates says one idea is scrappage schemes for older, polluting cars. She suggests these shouldn’t just offer an incentive towards a clean vehicle, but also even more attractive incentives for shifting from a private car to public transport or a car share. One UK trial, Coventry’s “mobility credits” scheme, allows people with petrol cars made before 2006 and pre-2016 diesel ones to exchange their car for up to £3000 to pay for public transport, bike rentals, taxis and e-scooters.
Improving standards
Beyond extending the area covered by clean air zones, a key step for the future will be tightening the emissions standards they impose in order to continue reducing air pollution. Modern petrol and diesel cars that can enter London and Birmingham’s zones without a charge still produce air pollution, as do electric vehicles because of wear on brake pads, tyres and road surfaces, but there is currently no timetable for when tougher rules might be imposed. By contrast, Brussels’s zone has weaker standards than London’s, but is .
Rodrigues says the focus for now in London is on expanding the ULEZ, not revising standards upwards. But she says: “The aspiration is zero carbon, zero pollution, so zero emissions zones are still being looked at.”
In the meantime, the bar for clean air is being raised. On 22 September, the World Health Organization (WHO) issued new air pollution guidelines, cutting the recommended maximum level for annual exposure to NO2 by 75 per cent.
Large areas across many cities still fail to meet the old WHO limits, let alone the new ones. The whole of London exceeds the new levels, and the expanded ULEZ won’t help to meet them. Rodrigues says the new guidance has made her more determined to make sure the city’s expanded ULEZ works well. “This is people’s lives, people’s daily lives being affected [by pollution],” she says.
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