Mayors from cities around the globe have urged Sadiq Khan to stay strong in the face of harsh criticism of his clean air policies. The Conservative party narrowly held the constituency of Uxbridge in a recent byelection, with its victory attributed partly to opposition to the London mayor’s upcoming extension of the capital’s ultra-low emissions zone (Ulez). A culture war over the role of cars in cities has erupted which has included arch comments from Keir Starmer, the Labour leader, who suggested his party was doing something “very wrong”. But other city leaders have told Khan to keep going, arguing that clean air is important for everyone, and said that they, too, have had to overcome strong opposition to green policies. Raymond Johansen, the mayor of Oslo, Norway, since 2015, has implemented some radical proposals. As the city tends to have worse air pollution in the winter, there are total diesel bans in place seasonally, and on days with bad pollution the toll for vehicles entering the city increases. Like Khan, Johansen has faced criticism, including from a single-issue political party set up opposing the toll ring. But he said he had found ways to counter the attacks on his clean air policies: “In general, we try to reduce traffic and congestion and we have a toll ring for all vehicles entering the city. In a city like Oslo, air quality is worst in the winter and on the coldest days. We lower speed limits on main roads and impose a fee on using studded tyres during winter to reduce the production of particle matter. “On days with very high air pollution the city can ban diesel private cars and diesel vans that have older technology than Euro IV. We can also increase the fees at the toll ring on days with high pollution.” As part of the bargain with the population, the local government does its bit to keep the air clean: “We clean the roads more and we increase the cleaning on days when we expect high levels of particulate matter.” Johansen said he was also looking at making public transport free on days with high pollution. Although the fees have had some opposition, Johansen said criticism had been mitigated because the funding was ringfenced for public transport. “The toll ring revenue in Oslo is almost entirely used for public transport infrastructure investments,” he explained. “In 2019, Oslo introduced more toll booths. This happened in several cities, and led to the birth of a new single-issue political party, the People’s Party Against Road Tolls. In the 2019 local elections, the party won three seats in the city parliament. In reality, most inhabitants experienced that their expenses were reduced, and in the polls for the upcoming elections in September, the party has very little support.” As in London, opponents of charges for polluting vehicles have tried to claim that it hurts the poorest in society. However, this was not true, Johansen said. “Common criticism against the toll ring, for example, is that low-income families will be much more affected than wealthy families. What we see in Oslo, however, is that those with the lowest incomes are those that are the most frequent users of the extensive public transportation system that Oslo has, and this service is improved with the revenues from the toll ring.” Johansen praised London’s Ulez scheme: “I see the establishment of the Ulez and its expansion as a sign of bold leadership from Mayor Khan, with the clear aim to protect the health of children and vulnerable citizens. If you really want to tackle poor air quality in a large city like London, you need to introduce measures that are substantial enough to make a real difference, even if it meets resistance from parts of the city. This serves as an inspiration to other cities.” Valérie Plante, who has served as mayor of Montreal, Canada, since 2017, has had to face a more extreme challenge than either Johansen or Khan – her city has been plagued by nearby wildfires, which have choked it with black smoke. “This summer’s forest fires have shown us that we are not immune to episodes of very bad air quality,” she said. “In fact, back in June for a few days, we ranked No 2 for worst air quality in the world due to smoke from the forest fires. Lives are at stake and people’s health is affected.” Plante took urgent action to clean up the air: “We needed to protect our citizens from the harmful effects of smoke. We organised clean air zones – libraries, public buildings with ventilation – and called on citizens to stay inside and use public transport as much as possible.” As well as this immediate response, her team has quickly devised a clean air plan, including a low emissions zone similar to London’s in the historic city centre, improving streets for cycling, and planting more trees to soak up pollution. Her city-centre zone will feature streets with pedestrian priority. Her clean air zone has faced opposition, but Plante is confident this will change. “Whenever car usage, parking or any car-related infrastructure is reduced, there is some kind of opposition to the proposed changes in status quo,” she said. “But I became mayor by committing to Montrealers that our administration would make our city more green, sustainable, inclusive and on a human scale, which requires major transformations, and in my experience, in the majority of cases, the opposition to these changes dissipates when citizens and businesses are made aware of the tangible benefits of public policies.” Plante hopes to create a zero-emissions zone in the city centre, and is taking inspiration from Khan. She recently went on a fact-finding mission to London to look at how the Ulez works. “It takes a great deal of courage, leadership and determination to do what London has done and continues to do, and we understand that the urgent air quality situation calls for an expansion of the scheme to reduce pollution and public health risks,” she said. “I support Mayor Khan, as air quality is fundamental to a decent quality of life and the Ulez scheme has shown its efficiency to reduce air pollution. In fact, many cities across the world are already looking at the Ulez in London and getting inspiration to elaborate similar schemes.” Milan’s mayor, Giuseppe Sala, has also continued to give support to Khan, and said he was inspired by Ulez as his city was plagued with traffic problems. “We have been inspired by the work done in London to support the scheme’s delivery – such as the scrappage scheme, and wider investment in public transport – and will look at the policy to help inform part of Milan’s own strategy to protect residents’ health as well as reduce the number of polluting vehicles on our streets,” he said. “As mayors we can all make a difference to the lives of people in our cities if we work closely together and learn from each other.”