C40 high-impact declarations are statements of political leadership by mayors from around the world. They are based on the most ambitious, science-based targets and lay out concrete delivery milestones, both for mitigation and adaptation.
Learn about all of the declarations and check the latest C40 declaration progress reports below.
Since 2017, mayors of world-leading cities have committed to taking urgent climate action by signing C40 declarations. To assess how cities have delivered on their pledges, C40 Cities conducted a thorough reporting process in 2021.