Climate leadership on the global stage

C40 works with mayors around the world to limit global heating to the 1.5°C target of the Paris Agreement while also delivering a green and just recovery from the COVID-19 pandemic and creating strong, fair economies that serve everyone. Mayors know that we cannot meet our climate goals without also working towards social and economic justice – it’s not just the right thing to do, it is the only way to prevent climate breakdown and secure the future we want.

C40 brings this message to the global stage with the specific objectives to:

  • ensure the COVID-19 recovery is green, just and city-driven;
  • build a coalition of 1,000+ cities committed to the principles of the Global Green New Deal;
  • raise global climate ambition ahead of the annual UN climate change conference (COP) and beyond;
  • achieve changes in policy, regulation and finance that will help cities implement high-impact climate mitigation and resilience actions;
  • end all public investments in fossil fuels, including coal.

C40’s city diplomacy work is a central component of one of our core global leadership standards that all C40 mayors must abide by. For cities, this work could take the form of engaging in global processes, signing on to accelerators and communiques, co-signing open letters or attending high-level meetings, all with the aim of positively influencing targeted national, regional and global discussions and decision-making related to climate change, economy and development.

Other city diplomacy-related projects include a C40 EU advocacy strategy and Adaptation Diplomacy, and collaboration with the Mayors Migration Council, Alliances for Climate Action (ACA) and the Coalition for Urban Transitions (CUT).

To contact the team, please email

Programmes & Initiatives