London Mayor Sadiq Khan and former New York Mayor Michael Bloomberg, writing in The Guardian for the start of Climate Action Week in London, argued that cities can achieve rapid, measurable reductions in air pollution using local data-driven policies — and that those successes offer a template for cities around the world.
The two mayors described air pollution as one of the world’s deadliest health threats that receives comparatively little public attention because it is largely invisible. “Every day, billions of people are inhaling air that is shortening their lives and making them sicker with every breath,” they wrote. “Every year, air pollution kills more than 8 million people worldwide. That’s more deaths than HIV, malaria and tuberculosis combined.”
Khan and Bloomberg said the heaviest burden falls on low- and middle-income communities and nations, but that the problem cuts across all classes and countries.
The centerpiece of their argument is London’s experience with nitrogen dioxide (NO2) pollution. According to the piece, experts at King’s College London predicted in 2016 that without action it would take nearly 200 years for the city to meet legal limits for roadside NO2. Khan said the city achieved that target in nine years.
“How? By following the data,” the mayors wrote. Khan described installing an extensive network of low-cost air quality sensors through the Breathe London program and engaging community leaders to place sensors in schools, hospitals and cultural centers.
The data, Khan said, informed policies including the ultra-low emissions zone (Ulez), which he described as the world’s largest clean air zone, and the rollout of zero-emission buses. “Taking those steps required facing down political opponents, pressure groups and vested interests but – as the data makes clear – the public has benefited,” they wrote. Khan noted that research published this month by Imperial College London found fewer Londoners were admitted to hospital with breathing and heart problems as a direct result of Ulez’s impact.
New York City, where Bloomberg served as mayor from 2002 to 2013, used a similar approach — deploying air-quality sensors to target city government efforts, according to the piece, and driving air pollution down to a 50-year low.
Building on both cities’ experiences, Bloomberg Philanthropies partnered with Clean Air Fund and C40 Cities to create the Breathe Cities program. Khan and Bloomberg wrote that the initiative provides mayors with real-time data on where pollution is worst, technical support to convert data into policy solutions, and a global network of cities to share ideas.
The mayors said nearly 1,200 air sensors have been deployed across 14 participating Breathe Cities, including the first hyper-local networks in Accra and Nairobi. Ten of the participating cities, they wrote, have committed to clean air zones by 2030 that will collectively cover an area where more than 18 million people live and work.
“By using data, cities are attacking the problem of air pollution as a public health challenge and simultaneously making progress in tackling the climate crisis, rather than retreating from environmental protection as some national governments are doing,” they wrote. “People rightly expect their local leaders to make it safe to walk outside. That includes protecting them from toxic pollution, as breathing clean air is a fundamental right.”
MSI previously reported on a similar hyperlocal approach in a Los Angeles neighborhood, where residents deployed their own sensors to document hazardous air quality in Pacoima.