London, UK (23 June 2025) – Mayors from across the C40 network, representing cities on five continents, have arrived in London for this year’s London Climate Action Week (LCAW), Europe’s largest city-wide climate festival. As frontline leaders in the global response to the climate emergency, these mayors will join more than 45,000 people attending over 300 events focused on driving fairer, healthier, and more resilient urban futures.
Throughout the week, city leaders will engage in discussions on improving air quality, expanding access to electric vehicle charging in underserved communities, and unlocking the green finance needed to accelerate climate solutions at scale.
Mark Watts, Executive Director of C40 Cities, said: “As city leaders gather from around the world, they’re not only showcasing success stories; they’re forging the partnerships and plans that will determine if we succeed in averting the worst of climate breakdown and protecting the people and places we love.”
“Twenty years since C40’s founding in London, cities’ leadership is now more important than ever in demonstrating to the world how to turn ambition into action.”
A key moment will come at a high-level breakfast roundtable hosted at the UK Foreign, Commonwealth & Development Office, in collaboration with the C40 Cities Finance Facility (CFF) and the Urban Climate Action Programme Climate Action Implementation (UCAP CAI). This exchange between international and UK mayors will showcase how C40 and fellow cities are accelerating climate action at scale, integrating climate at the heart of governance, scaling investment-ready solutions, and delivering inclusive benefits to urban residents. CFF and UCAP CAI programmes are already making a difference to the lives of the most vulnerable communities, with cities in the programme projected to leverage over GBP 800m in climate finance, avoid or reduce at least 1.7 million tonnes of CO2e every year; the equivalent of avoiding the emissions of a city the size of Manchester every year. Over 10 years, it would cumulatively reduce the emissions of a city the size of Kuala Lumpur (Malaysia) or Berlin (Germany).
Sakaja Johnson, Governor of Nairobi, said: “Thanks to FCDO’s UCAP, Nairobi’s solar-powered cold room helps reduce food waste and boosts food security, real climate solutions benefiting communities and supporting resilient city development.”
As part of LCAW, C40 and Uber will formally launch a new partnership to accelerate the rollout of electric vehicle charging infrastructure in Phoenix, Boston, and London. Unveiled at the SmartCitiesWorld Cities Climate Action Summit, the programme will support high-mileage commercial drivers such as ride-hail, taxi, and freight workers by using new data-driven tools to plan equitable, high-use charging networks. The event features a panel and workshop involving deputy mayors and transport leads from cities across Europe and North America, showcasing how public-private partnerships can drive clean air, green jobs, and more accessible urban mobility.
Rebecca Tinucci, Global Head of Sustainability, Uber, said: “Uber is committed to an all-electric future.”
“With the right charging infrastructure in place, drivers can earn more, deliver a better rider experience, and help tackle air pollution.
“We’re proud to partner with C40 and city leaders to help unlock EV infrastructure where it is most needed. Reliable, accessible charging will help accelerate economic opportunity for thousands of drivers and create healthier communities in the process.”
Another highlight of the week will be the premiere of Transforming Cities II, the second series of short films produced by C40 Cities in partnership with BBC StoryWorks. The series profiles 17 inspiring stories from around the world, from Milan to Miramar and Tokyo to Tallinn, highlighting the individuals and communities redefining how cities grow, adapt, and thrive in the face of climate breakdown. With a focus on mitigation, adaptation, and inclusion, the series shows how local climate action is delivering global impact.
On 25 June, C40 and The Conduit will co-host Bold Cities, Brave Mayors: Governing for a Livable Planet, bringing together the mayors of Nairobi and Montreal, alongside former C40 Chair and Mayor of Toronto David Miller, for a powerful dialogue on urban climate leadership. The event will highlight how local governments are tackling the climate crisis through democratic innovation, inclusive governance, and urgent action, introducing new audiences to C40’s collaborative approach.
LCAW also marks two years since the Breathe Cities initiative was announced, inspired by the Breathe London air quality programme that has installed more than 400 sensors and empowered 60 community groups to access real-time data on the air they breathe. The global initiative has since expanded to 14 cities on five continents, where over 1,000 air quality sensors have been deployed, and is supporting clean air policies from Nairobi to Warsaw, with the goal of cutting air pollution in participating cities by 30% by 2030.
Jane Burston, CEO of the Clean Air Fund, said: “In just two years, Breathe Cities has grown from our initial pilots in London and Warsaw into a global movement of cities across the world.
“From Nairobi’s first city-owned air quality sensor network to Warsaw’s pioneering Clean Air Zone, we’re seeing these cities drive change for their residents. Cities are also sharing knowledge and working together to accelerate action for clean air and climate globally.
“As we celebrate the second anniversary of Breathe Cities going global at London Climate Action Week, we’re marking the progress made for the 77 million residents in these cities who could breathe easier.”
Also during the week, C40 is set to sign a strategic Memorandum of Understanding with the Centre for Liveable Cities (CLC) to deepen collaboration on people-centred, climate-resilient urban development. The MoU aims to strengthen city networks, promote shared learning, and advance regenerative, inclusive city planning across the Asia-Pacific and beyond. As a first step, C40 and CLC, in partnership with Arup, will host a mayoral panel on 25 June titled Urban Futures Reimagined, featuring city leaders from Oslo, Medellín, and London. The event will spotlight how regenerative design, nature-based solutions, and community engagement are helping cities build resilience, cut emissions, and foster social equity.
This year’s LCAW also marks the 20th anniversary of C40’s founding by former Mayor of London Ken Livingstone. From a meeting of G20 city leaders in 2005 to a global network of nearly 100 cities representing over 900 million people, C40 continues to demonstrate that city leadership is essential to meeting the goals of the Paris Agreement and protecting communities from the worst impacts of climate breakdown.