2024 brought its fair share of challenges for global climate action, but cities around the world continued to lead the way with creativity and determination.
From meaningful dialogues with Pope Francis at the Vatican and the release of the latest C40 High-Impact Accelerator reports, to welcoming Casablanca to our network and President Lula da Silva’s powerful presence at the Urban 20 communiqué handover, 2024 was a year of significant action.
C40 cities and their mayors remained steadfast in their commitment to a science-based, people-first approach—advancing two of C40’s key goals:
1. Help get the world off fossil fuels in order to halt climate breakdown
2. Address the impacts and injustices of climate breakdown
As the momentum to phase out fossil fuels and prioritise climate justice grows, mayors across the globe are leading the charge. Join us as we reflect on some key moments from 2024, paving the way for a greener, fairer future where everyone can thrive.
1. Brazil’s President Lula praises cities’ climate leadership, raising hope for COP30
C40 Co-Chair and Mayor of Freetown, Yvonne Aki-Sawyerr, led a delegation of mayors at the Urban 20 (U20) Summit in Rio de Janeiro in November. Mayors set a strong, people-focused climate agenda ahead of the G20 Summit, ensuring subnational priorities were clearly represented as national leaders held critical discussions.
As the summit came to a close, C40 Vice Chair Mayor of Rio de Janeiro Eduardo Paes handed the U20 communiqué to President of Brazil Lula da Silva, who praised cities for their leadership in tackling inequality and the climate crisis and vowed to bring their message of progress and solidarity to the G20 Summit.
President Lula said: “C40 is committed to tackling the climate crisis and contributing to limiting global warming to 1.5 degrees while building healthy, equitable and resilient communities. The voice of the cities needs to be heard.”
With COP30 set to take place in Belem, Brazil, in 2025, President Lula’s strong commitment to climate action and global collaboration brings hope for a much more ambitious outcome than COP29 in Baku.
As C40 Cities Executive Director Mark Watts explains below, cities have much to offer when it comes to more effective climate negotiations:
Brazil’s updated Nationally Determined Contribution (NDC) climate plan places the Coalition for High Ambition Multi-Level Partnerships (CHAMP) and “climate federalism” at its core—a bold vision that sets a high standard for other nations as they prepare their NDCs ahead of COP30.
2. C40 Co-Chairs Mayors Aki-Sawyerr and Khan fly the flag for cities on the global stage
In May, C40 Co-Chair Mayor of London Sadiq Khan led a delegation of mayors from Rome, Boston, São Paulo, Yokohama, and more at the Vatican’s From Climate Crisis to Climate Resilience summit. The mayors took part in an audience with His Holiness Pope Francis, where they discussed their climate strategies and challenges, aligning with the Pope’s call to action in his Laudate Deum.
A key achievement was the signing of the Protocol for Climate Resilience, which calls for greater collaboration between cities and national governments to meet climate targets. As the summit concluded, Mayor Khan highlighted the success of London’s ultra-low emission zone, emphasising how the world’s largest clean air zone is protecting the health of residents. Watch below:
Later in the year, both C40 Co-Chair Mayor of Freetown Yvonne Aki-Sawyerr and Mayor Khan headed to Climate Week NYC for the General Assembly and Summit of the Future, with a clear message for national leaders: “It’s time to leave fossil fuels behind.”
Mayor Aki-Sawyerr also became the first mayor to address the Global Renewables Summit, seeking to triple renewable energy globally by 2030. According to C40 research, global investment in renewables needs to increase more than fourfold to over US$5 trillion annually to stay on the 1.5°C pathway. See highlights from Mayor Aki-Sawyerr’s Climate Week NYC engagements:
3. It’s in the Air: Clean air zones transform cities
Cities worldwide made bold strides in tackling air pollution and the climate crisis by rethinking urban travel and embracing clean air zones. These zones, championed by over 30 C40 cities, are transforming streets, cutting emissions, and prioritising people over cars.
Starting in July, the ‘It’s in the Air’ campaign brought global attention to the benefits of clean air zones. Launched by C40 Vice Chair Mayor of Paris Anne Hidalgo, it spanned eight weeks, involving over 10,000 residents in workshops, events, and installations across cities like Bogotá, Johannesburg, Quito, Seattle, and Stockholm. The campaign reached over 5 million online, amplifying stories of progress and hope.
Mayor Khan joined the campaign’s launch in Paris, showcasing London’s impressive new clean air zone data and learning how Paris transformed its waterways and streets ahead of the Olympic Games. Watch as Mayor Khan championed the “It’s in the Air” campaign.
Supporting this movement, C40 released a Clean Air Toolbox – a practical guide to help cities design and implement clean air zones, engage communities, and secure public support.
The momentum is clear: clean air zones are a key part of creating healthier, more liveable cities. The baton has been passed, and the journey continues into 2025.
4. Cities are on track for 50 million good green jobs, with 16 million already in megacities worldwide
At the 2022 C40 World Mayors Summit, mayors committed to drive the creation of 50 million good green jobs in cities by 2030. In June at London Climate Action Week, we proved they’re delivering on their word. C40’s latest analysis identified almost 16 million good green jobs in global megacities.
C40 Co-Chair Mayor Khan said: “I’m proud that we are on our way toward achieving our goal of 50 million good, green jobs by 2030, with 16 million jobs already supporting the transition to a green economy across 74 cities worldwide.”
Continuing the momentum of C40’s good green jobs campaign, in December, C40 launched the Jobs For Our Future initiative in an online event with LinkedIn. Joined by 2,000+ viewers from around the world, the event explored what green jobs are, why they matter, how cities drive their growth, key insights from LinkedIn’s 2024 Green Skills Report, and tips for applying and networking.
Alongside youth, unions, and businesses, mayors are creating inclusive and sustainable economies, but more investment in cities is urgently needed to scale and speed up the green and just transition.
5. C40’s High-Impact Accelerators boost climate action
C40’s High-Impact Accelerators help cities take urgent climate action by focusing on key sectors and implementing science-based solutions. By joining, cities demonstrate their commitment to tackling the climate crisis while benefiting from C40’s expertise, peer learning, and resources.
In early 2024, C40 released the latest Accelerator Reports, assessing how mayors are delivering on commitments across vital areas such as air quality, construction, buildings, food systems, and waste management.
A summary of the progress, achievements and impact of taking science-based, inclusive climate action can be accessed in the central report: C40 Accelerator Progress Report 2023 [also in French, Portuguese and Spanish].
2024 demonstrated the power of collaboration in advancing climate solutions. Thank you to our partners and supporters for your dedication—we look forward to achieving even greater impact together in 2025.