- Mayor Khan to address world leaders at the COP31 Urban Ministerial High-Level Plenary, warning that climate disinformation threatens progress on climate action and democratic freedoms.
- “Climate disinformation is a one-two punch to the planet and democracy,” he will say.
- New C40 research across five global cities finds around one in three residents identify more closely with misleading climate claims than accurate information, rising to almost half in Cape Town.
- Michael Bloomberg and international mayors pay tribute to Mayor Khan’s five years of C40 leadership, during which cities have advanced green jobs, climate investment and clean air, and strengthened the voice of the Global South.
Antalya, Türkiye (12 November 2026) – The Mayor of London and C40 Cities Co-Chair, Sadiq Khan, will warn world leaders at COP31 that climate disinformation threatens both the planet and democracy, as new international research reveals the scale of the challenge facing cities around the world.
Addressing the World Leaders Summit’s High-Level Dialogue on Urban Resilience, Adaptation, and Climate Action at the COP31 climate summit in Antalya, Mayor Khan will call for a global fightback against misleading claims about climate change and the policies designed to tackle it. Aligning with the UN initiative on Information Integrity, Mayor Khan will warn that organised efforts to distort public debate threaten to undermine progress on climate action.
His intervention comes as new research commissioned by C40 Cities and conducted by Panterra Group across London, Santiago, Cape Town, Melbourne and Quezon City in the Philippines reveals that around one in three respondents sided with misleading statements about climate change and climate policies when presented alongside accurate information.
The research, involving more than 4,700 residents across five cities, also reveals widespread exposure to suspected misinformation. Across the five cities, between 73% and 90% of residents reported encountering information they believed could be false or misleading. Yet majorities also expressed a desire for trustworthy information from their local governments, highlighting the important role city leaders can play in tackling the problem.
Key findings include:
- Santiago: 90% of residents regularly encounter suspected misinformation.
- London: 84% report regularly encountering suspected misinformation.
- Melbourne: 82% report regular exposure to suspected misinformation.
- Cape Town: Around half of residents sided with the disinformation statements presented. The city is working with C40 to step up its efforts to counter disinformation, particularly around public services, through the establishment of new dedicated communications capacity.
- Quezon City: Between 31% and 35% identified more closely with misleading claims about climate change, extreme heat and air pollution.
The surveys tested claims suggesting that extreme heat is no worse than in previous generations, that climate policies restrict personal freedoms, and that it is too late to take meaningful action on climate change.
The findings highlight a challenge for governments seeking to deliver the emissions reductions, cleaner air and greater protection against extreme weather promised through international climate commitments. Misleading claims about the costs, effectiveness or consequences of climate policies risk making implementation more difficult.
Sadiq Khan, Mayor of London and C40 Cities Co-Chair, is expected to say: “Climate disinformation is like a one-two punch to the planet and democracy. But here in Türkiye, we’re calling on the world to get its guard up to defend itself and mount a comeback – to deal a knockout blow to the dark forces distorting debate.
“It’s time to resist the attacks and stand up for the facts – with a relentless focus on unlocking the finance and expertise we need to fund climate action and adaptation around the world. London and other great cities around the world are showing we can overcome this challenge, we can win this fight and we can create a fairer, greener, healthier and more prosperous planet for everyone.”
Mayor Khan will draw on London’s experience confronting misleading claims about climate policies, including the expansion of the city’s Ultra Low Emission Zone (ULEZ), which has helped reduce harmful air pollution across the capital.
Mayor Khan is expected to say: “While we act on the scientific consensus, the climate deniers and delayers are playing dirty with one last trick up their sleeve: climate disinformation.
“London is no stranger to lies. When we expanded our clean air zone, now the largest in the world in 2023, we faced one of the most sophisticated disinformation campaigns ever seen. We overcame it and won. But evidence from all five continents shows London was just the canary in the coal mine.”
In June 2026, Mayor Khan launched City Climate Facts during London Climate Action Week, an initiative designed to help cities counter climate misinformation and disinformation, strengthen public understanding of climate policies and rebuild trust in an increasingly polluted information environment.
Separate research for C40 by disinformation analysts at Valent has identified that many C40 Cities have seen a surge in coordinated attacks surrounding El Nino. Disinformation ranges from spreading catastrophism to domestic political weaponisation. Co-ordinated networks drive substantial bot amplification across both themes with inauthentic discourse constituting up to 59% of engagements in C40’s Brazilian cities.
Five years of international climate leadership
Mayor Khan’s intervention at COP31 is the latest in a series of significant international appearances during his five years as C40 Co-Chair, in which he has championed the role of cities in delivering practical climate action.
Since becoming C40 Chair in 2021, he has helped strengthen a network of 97 major cities representing 920 million people and nearly a quarter of the global economy. More than three-quarters of C40 cities have already reached peak emissions, while the network’s cities are reducing per capita emissions five times faster than the global average.
Mayor Khan has also championed cleaner air in cities around the world by launching Breathe Cities. The initiative, delivered by Bloomberg Philanthropies, C40 Cities and Clean Air Fund, is helping improve air quality for 88 million people.
It is supporting mayors with the tools needed to take bold action, with 26 local clean air policies implemented to reduce pollution and improve quality of life, from electrifying fleets and introducing clean air zones to phasing out highly polluting solid-fuel heating. The support includes data to drive evidence-based solutions, with over 1,200 sensors deployed to help cities monitor hyper-local pollution and inform the development of ambitious clean air policies.
Mayor Khan also launched the C40 Clean Air Accelerator, now including 52 mayors, representing over 250 million people, who have committed to achieving World Health Organisation air quality guideline-aligned targets through equitable, data-driven action.
Signatory cities have achieved an average 6% reduction in PM2.5 and 11% reduction in NO2 since 2018, improving public health and wellbeing, promoting fairness, and creating good, green jobs. This translates into more than 21,000 lives saved from air pollution, 240,000 years of life gained, and over 48,000 cases of childhood asthma prevented worldwide – saving $47 billion.
A central priority of his leadership has been ensuring that cities in the Global South have a stronger voice in international climate decisions. In 2023, he introduced C40’s Co-Chair model alongside Freetown Mayor Yvonne Aki-Sawyerr, while directing two-thirds of C40’s programme funding towards cities in the Global South.
Mayor Khan has also taken the case for city-led climate action to the highest levels of international diplomacy, becoming the first UK mayor to address world leaders at the UN General Assembly and leading a mayoral delegation to the Vatican for Pope Francis’s 2024 climate summit.
At COP30 in Brazil, he introduced the Yearly Offer of Action, through which mayors publicly set out practical climate commitments for the year ahead and report on their progress, helping shift international climate discussions from promises towards delivery.
Michael R. Bloomberg, UN Special Envoy on Climate Ambition and Solutions and founder of Bloomberg L.P. and Bloomberg Philanthropies, said: “As co-chair of C40, Sadiq Khan has been a champion for cities around the world, helping leaders to aim high and put ambitious climate plans into action.
“He’s led by example through Breathe London and other bold efforts he’s introduced as mayor, showing how improving air quality, cutting greenhouse gas emissions, and growing the economy all go hand in hand.
“We thank him for all his strong leadership at C40 and look forward to continuing to work together as he builds on the progress he’s leading in London.”
Mayor of Freetown and C40 Co-Chair Yvonne Aki Sawyerr said: “It has been a privilege to work alongside Sir Sadiq Khan as Co-Chair of C40. Throughout his leadership, Sadiq has demonstrated that tackling the climate crisis requires listening to the cities and communities experiencing its greatest impacts and ensuring they have a meaningful voice in shaping the solutions.
“His decision to introduce C40’s Global North and Global South Co-Chair model was an important step towards making our network more representative and inclusive. Together, we have worked to ensure that cities have a stronger voice internationally, and that the needs of communities on the frontlines of the climate crisis are reflected in global decisions.
“Climate disinformation threatens the trust and cooperation we need to deliver change. By helping mayors respond with credible information and by demonstrating the real benefits of climate action, Sadiq has strengthened C40’s ability to address the climate crisis. I am proud of what we have achieved together, and I am determined to build on that legacy.”
Mayor of Boston and C40 Vice Chair Michelle Wu said: “From extreme weather to skyrocketing energy costs, cities and mayors are on the front lines of the climate crisis. As Co-Chair of C40, Mayor Khan brought together leaders from across the world to advance ambitious climate action and build healthier, more resilient cities for generations to come.”
“I’m grateful to Mayor Khan for his bold leadership, and I look forward to building on our progress to continue delivering cleaner air, safer streets, and healthier homes for residents in Boston and beyond.”
Mark Watts, Executive Director of C40 Cities, said: “Climate disinformation isn’t just an attack on the truth. It’s an attack on the work cities are doing to improve people’s lives. When false claims undermine public confidence in cleaner air, better transport and green investment, it’s ordinary people who lose out.
“Over the past decade, Mayor Khan has shown that the best answer to those trying to delay action is to deliver results. London is healthier, greener and home to a thriving green economy, while cities around the world are demonstrating how climate action creates jobs, protects communities and improves lives.
“Through City Climate Facts, we’re helping mayors confront disinformation with credible evidence and build public trust. At COP31, our message is clear: we cannot allow those spreading falsehoods to stand in the way of a cleaner, safer and more prosperous future.”
At COP31, C40 is calling for stronger cooperation between national and local governments, greater access to urban climate finance and support for a just transition that delivers tangible benefits for communities.
C40 argues that these priorities must be accompanied by clear, reliable public information. As governments move from setting climate targets to implementing policies, maintaining public confidence will be essential to delivering change at the scale and speed required.
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