23 June 2025, London, UK – Mayor of London Sadiq Khan has been appointed as the Special Envoy, Fossil Free Cities for the Fossil Fuel Non-Proliferation Treaty Initiative. The new role is aimed at accelerating the global transition away from fossil fuels and amplifying the voice of cities in the fight against the climate crisis.  

Cities are on the frontlines of the climate emergency, and they are also where the most innovative solutions are being pioneered. As Special Envoy, Mayor Khan will champion the role of cities and subnational governments in shaping global climate policies, ensuring they have a seat at the table in the urgent effort to phase out fossil fuels equitably, and finance a more just, sustainable future. Over 135 cities and subnational governments, including London, California, and 17 national capitals, have already endorsed the Fossil Fuel Treaty proposal.  

Mayor of London and Co-Chair of C40 Cities, Sadiq Khan said: “Cities are on the frontlines of the  climate crisis, but they are also where the solutions are being forged. As Special Envoy, I am committed to ensuring that cities and subnational governments are not just heard but actively involved in shaping the global response to this crisis. The Fossil Fuel Treaty Initiative represents an important step toward a sustainable, healthier future for all.”

Mayor Khan’s appointment comes at a pivotal moment. Mayors have long been at the forefront of progressive change, holding the line on climate action amid global instability. At COP28, cities secured a seat at the table in UN climate negotiations for the first time in history, marking a significant shift in recognizing the power of local leadership.  

Tzeporah Berman, Co-Chair and Founder of the Fossil Fuel Non-Proliferation Treaty Initiative, said: “Cities are the beating heart of climate action, and Mayor Khan’s leadership in London has set a gold standard for what is possible when bold, visionary leadership meets unwavering commitment. As Special Envoy, he will amplify the voice of cities on the global stage, ensuring the Fossil Fuel Treaty is not just a framework but a catalyst for transformative change that reflects the urgent needs and aspirations of local communities. This is more than a step—it’s a leap toward a more just, sustainable, and fossil-free future for all.”  

Fossil fuels are a direct threat to urban health, with cities bearing the brunt of air pollution. Forty-one percent of cities worldwide have air pollution levels seven times higher than the World Health Organization’s recommendations, and 97% of cities in low- and middle-income countries face unsafe air quality. With three-quarters of global energy consumed in cities, a just transition away from fossil fuels is essential to safeguarding public health and well-being.  

Mark Watts, Executive Director of C40 Cities, welcomed the announcement: “Mayor Khan’s leadership in London has demonstrated that bold climate action is not only possible but transformative. His appointment as Special Envoy is a testament to the critical role cities must play in the global effort to phase out fossil fuels. At C40 Cities we have placed ending the use of fossil fuels at the very core of what we do, and we are proud to stand with Mayor Khan and the Fossil Fuel Treaty Initiative. Cities are the doers of climate action and now is our time to create a better, safer future for urban residents everywhere.”

London has emerged as a global model for urban sustainability. Initiatives like the Ultra Low Emission Zone (ULEZ) have drastically reduced air pollution, putting the city on track to achieve net-zero carbon emissions by 2030. These policies have not only protected the environment but also improved public health, created green jobs, and built a more resilient city.  

Mayor Khan has also led efforts to divest from fossil fuels, working with the London Pension Fund Authority (LPFA) to implement a climate change policy covering nearly £10 billion in assets. This includes no new active investments in fossil fuel companies and scaling up green investments. As co-chair of the C40 Cities Divest/Invest Forum, Mayor Khan has helped expand fossil fuel divestment globally, sharing tools and knowledge to accelerate the transition.  

Equity is at the heart of the fossil fuel phase-out. Mayor Khan is committed to ensuring that the benefits of this transition—cleaner air, sustainable jobs, and resilient infrastructure—are shared by all, particularly vulnerable communities.  

As Special Envoy, Mayor Khan will advocate for the Fossil Fuel Treaty Initiative on the global stage, engaging with national, regional, and international forums to build momentum for this critical initiative.  

“The climate crisis is the defining challenge of our time, and cities are leading the way. The Fossil Fuel Treaty Initiative is a concrete global policy solution that Mayors and Subnational leaders can uphold to accelerate the just transition towards sustainable sources of energy for all. Together, we can build a world that is not only cleaner but also fairer and more resilient for generations to come,“ complemented Mayor Khan.  

The Fossil Fuel Treaty Initiative is now supported by 17 countries, actively participating in discussions on a global, binding mechanism to address fossil fuels. They’re joined by over 130 cities and subnational governments, including the State of California, alongside a massive coalition: over 1 million citizens, nearly 4,000 civil society organizations, 3,000+ academics and scientists, hundreds of health professionals and institutions like the WHO, faith leaders including the World Council of Churches, 850+ elected officials, the European Parliament, 101 Nobel laureates, 25 banks, unions representing 35 million workers, businesses, youth advocates, and Indigenous peoples. They are all coming together to demand a just, equitable and financed transition through the negotiation of a Fossil Fuel Treaty.