Cities need support from national and international levels to deliver climate action
Cities are taking bold action on climate, but they can’t do it alone. Whether it’s building bike lanes, retrofitting buildings, or protecting neighbourhoods from flooding, progress often depends on decisions made by national governments and international bodies. These higher levels of government set the policies, regulations, and funding that enable or block local climate action.
C40 works to give cities a voice in these bigger discussions. When world leaders meet at UN climate conferences (COP) or G20 summits, C40 ensures mayors are in the room, sharing what’s working on the ground, and pushing for the support cities need. This includes securing funding, changing regulations that create barriers, ending public investment in fossil fuels, and ensuring climate policies benefit all communities, not just the wealthiest.
Through this work, over 1,000 cities have committed to the principles of the Global Green New Deal. International negotiations are showing greater climate ambition, and supportive policies are enabling cities to turn this momentum into tangible benefits for residents.
What makes city diplomacy work
Effective engagement in global discussions means moving beyond traditional advocacy. Here’s what works:
Show what cities are delivering
Real results carry more weight than promises because they provide concrete proof of what works. When mayors showcase measurable emissions cuts, new jobs, and health improvements, it proves what’s possible and strengthens the case for policy change.
Work with other governments collaboratively
Cities and national governments depend on each other. Cities bring implementation expertise; national governments provide policy, regulation, and finance. The strongest results come from collaboration and partnership, not opposition.
Connect local action to global goals
Translating city-level work into language that resonates internationally helps global leaders understand how local action delivers on commitments like the Paris Agreement.
Champion equity in every discussion
City diplomacy ensures global conversations recognise that climate action must work for everyone. Mayors bring frontline perspectives on how climate impacts and solutions affect communities differently based on income, race, and geography.
Create real platforms for city voices
Urban 20, a designated city presence at COP, and other structured mechanisms give mayors formal channels to influence decisions rather than being shut out of conversations that affect their ability to act.
How cities engage globally
Different initiatives provide entry points for cities to shape climate policy and finance at global, regional, and national levels.
Urban 20: influence G20 decisions
Created in 2017, Urban 20 gives cities a platform to engage with G20, a group of twenty of the world’s largest economies. Mayors develop recommendations on issues where urban action matters, present them directly to G20 leaders, and push for the policy and finance changes that enable cities to deliver.
COP: demonstrate city action at UN climate conferences
C40 cities engage as formal observers at UN Climate Change Conferences. City pavilions showcase local action, meetings with national delegations build relationships, and joint statements demonstrate what mayors are committed to delivering.
Green and Just Recovery Agenda: champion equitable solutions
C40’s Green and Just Recovery Agenda advances rapid, equitable recovery from crises rooted in Global Green New Deal principles, delivering economic, health, and emission reduction benefits worldwide.
Questions about city diplomacy and advocacy?
Contact the city diplomacy team at citydiplomacy@c40.org to discuss how cities can engage in global, regional, and national discussions that advance climate action.
Frequently asked questions
What makes city diplomacy different from regular advocacy?
City diplomacy means mayors can demonstrate what’s already working rather than just calling for change. When cities show up with data on emissions reductions, job creation, and health improvements from policies they’ve implemented, it changes the conversation. Cities become essential partners in delivering global climate goals rather than just stakeholders requesting support.
How does Urban 20 actually work?
Urban 20 (U20) establishes a platform for cities to collectively inform G20 negotiations. Each year, cities present a Communiqué to G20 leaders, elevating urban priorities on socioeconomic development and the climate crisis within the global agenda. Leadership rotates annually among Chair cities from the G20 host country.
Can any C40 city participate in COP?
C40 cities engage as formal observers at UN Climate Change Conferences. This includes hosting pavilions, participating in events, meeting delegations, and presenting joint statements. C40 coordinates participation to share evidence of what works, enabling cities to replicate successful strategies and accelerate climate action.
How do cities coordinate their advocacy efforts?
C40 coordinates collective action to amplify city voices. This includes organising joint statements signed by multiple mayors, briefing cities ahead of key political moments like COP or G20 summits, facilitating meetings between mayors and national government officials, and sharing intelligence about policy developments that affect cities. Working together through C40 gives cities more influence than acting individually.
What has city diplomacy achieved?
City diplomacy has secured policy changes that enable local climate action, built recognition of cities as essential partners in delivering Paris Agreement goals, influenced funding decisions that direct resources to urban climate solutions, and created formal platforms like Urban 20, where mayors now have structured access to G20 leaders. Over 1,000 cities have committed to ambitious climate action through these efforts.
Programmes and Initiatives
Created in 2017 under the mayoral leadership of Buenos Aires and Paris, the Urban 20 (U20) is a city diplomacy initiative that provides a platform for urban engagement in the Group of 20 (G20). It strengthens the role and influence of cities as economic and political leaders in global negotiations.
As formal observers of the COP process, C40 cities use this global platform as an opportunity to showcase their commitments to ambitious climate action and their achievements towards reaching Paris Agreement goals, and to inspire the global community to enhance their ambition and put inclusive climate action and equity at the heart of all decision-making – in line with the Global Green New Deal.
Our vision for a rapid, equitable recovery from COVID-19 crisis rooted in the principles of a Global Green New Deal to deliver transformative economic, health and emission reduction benefits across the world.
