The importance of city leadership at COP
The annual United Nations Climate Change Conferences, known as COPs (Conference of the Parties), bring together national governments to set global climate targets and agree on how to meet them.
Most of the world’s population live in cities. Mayors significantly influence systems like transport, buildings, energy, and waste, which offer the fastest routes to cutting emissions. Since city action is crucial for delivering on COP commitments, mayors need a prominent voice at the conference.
C40 mayors attend COP to showcase what cities are already delivering, call for the finance and partnerships needed to scale climate action, and push for cities to be recognised as essential partners in meeting the goals of the Paris Agreement.
Each COP has a different focus, shaped by the host country and the most pressing issues of the moment. Explore below how C40 mayors have shaped the agenda at each summit.
COP30: Belém, Brazil, November 2025
From negotiation to implementation
A decade on from the Paris Agreement, COP30 in Belém is the most significant climate summit since COP21 in Paris. For the first time, subnational leadership (such as cities, states, and regions) was recognised as an official part of the COP process, with the COP30 President highlighting in his opening speech that mayors have “an absolutely essential role in implementing the decisions of the COPs.”
C40 mayors arrived with a clear message: cities are already delivering on climate commitments, and COP needs to shift from negotiation to implementation.
Key outcomes and announcements
Multilevel partnerships: Brazil and Germany were announced as the first Co-Chairs of CHAMP (Coalition for High Ambition Multilevel Partnerships), now embraced by 77 countries.
Just transition: COP30 agreed to develop a new just transition mechanism, putting people and equity at the centre of climate action.
Adaptation finance: A new call to triple adaptation finance by 2035.
Action Agenda: The COP Action Agenda was renewed for five years as an engine to drive implementation.
Belém Declaration: Colombia launched the Belém Declaration on fossil fuels, together with a first international conference on a just transition away from fossil fuels, and invited cities and subnationals to participate. C40 backed the declaration.
What C40 called for
- Officially recognise cities and subnational governments as full partners in COP outcome texts
- Create a formal space at COP for multilevel climate action
- Mobilise more funding for local climate action, especially in the Global South
- Include cities in national climate plans (NDCs) to raise ambition and improve delivery
COP29: Baku, Azerbaijan, November 2024
Pushing for direct finance and multilevel partnerships
COP29 took place alongside the U20 Summit in Rio de Janeiro, where more than 70 mayors met to ensure G20 leaders heard cities’ voices on climate issues. C40 mayors used both platforms to push for stronger multilevel partnerships and direct funding to help cities deliver faster, fairer climate action.
Key outcomes and announcements
Finance: Mayors from G20 countries called for USD 800 billion annual investment towards climate action in cities by 2030.
C40 Cities Finance Facility: C40 announced a new call for cities to apply for climate action support.
NUS Cities partnership: C40 and NUS Cities announced a new partnership at COP29.
COP28: Dubai, UAE, November–December 2023
United in action for a fossil-free future
At COP28, C40 mayors stood united in calling for an end to the fossil fuel era, with cities and businesses issuing a joint call for an urgent phaseout. C40 also announced a historic new Co-Chair model, with the Mayors of London and Freetown leading the network together for the first time.
Key outcomes and announcements
Fossil fuels: Cities and businesses called for the urgent phaseout of fossil fuels.
Co-Chair model: C40 announced Sadiq Khan, Mayor of London, and Yvonne Aki-Sawyerr, Mayor of Freetown, as Co-Chairs.
Breathe Cities: A new cohort of cities joined the initiative to fight toxic air pollution.
Water Safe Cities: C40 launched the Water Safe Cities Accelerator to tackle flooding and drought.
Green shipping: Singapore, LA and Long Beach unveiled a partnership strategy on a green and digital shipping corridor.
Loss and damage: C40 and the Scottish Government launched a partnership and report on locally-led inclusive climate action for loss and damage.
MDB financing: The first study on multilateral development bank funding for Global South cities revealed significant shortfalls in financing for urban climate projects.
COP27: Sharm el-Sheikh, Egypt, November 2022
City climate action becomes a COP priority
COP27 marked a shift in how cities were recognised in global climate negotiations. For the first time, a COP presidency made urban climate a key priority, and the first-ever Ministerial Meeting on Urbanisation and Climate Change put a spotlight on city-led solutions.
C40’s mayoral delegation was led by Global South mayors, recognising the importance of frontline voices in the fight against climate breakdown.
Key outcomes and announcements
SURGe: Egypt launched Sustainable Urban Resilience for the next Generation, the first time a COP presidency made urban climate a key priority. C40 is a partner and co-leads the building working group.
City climate finance: The National Development Banks Urban Climate Action Programme was launched, with C40 as a technical partner.
NDC Ambition Handbook: C40 unveiled a handbook for countries to identify impactful and inclusive climate actions, inspired by the experience of cities.
Migration: C40’s mayoral delegation called on national governments to increase adaptation finance to 50% of total climate finance.
COP26: Glasgow, UK, November 2021
The path to a green, just and prosperous future
COP26 took place as cities were emerging from the COVID-19 pandemic, with C40 mayors making the case for a green and just recovery that prioritised public services, green jobs, and giving public spaces back to people and nature.
Key outcomes and announcements
Clean Construction Coalition: C40 launched a coalition to halve emissions from the global built environment sector by 2030.
Electric buses: A new USD 1 billion commitment from investors to deliver zero-emission buses in Latin America.
Global Cities Climate Action Exhibition: In collaboration with Arup, C40 hosted an exhibition showcasing initiatives from Auckland, Beijing, Bogotá, Istanbul, Jakarta, Lima, London, Los Angeles, Mumbai, Nairobi and Washington, D.C.
related
Where global mayors, climate experts, and youth activists unite to accelerate urban climate action.
How C40 helps cities access climate finance to shape greener, healthier and more resilient cities.
C40 ensures mayors have a voice at COP, G20, and other forums where decisions are made that affect cities’ ability to deliver climate action.
