C40 Cities: When local action meets global ambition

Behind every climate solution is a community and a city that dared to lead.

A colourful collage of mayors from across the world
Explore our cities
C40 has 97 member cities
Making up more than 22% of the global economy1

Accelerator Reports

Latest Reports Now Available

Since 2017, 74 forward-thinking C40 cities have been driving transformative action in critical sectors through C40’s High-Impact Accelerators.

In the latest Accelerator Reports, we celebrate the progress and impact of cities’ climate actions.

© Laure Rees-Smith – C40

Sources:
1. Oxford Economics data + C40 modelling and World Bank for global GDP.