The C40 Knowledge Hub is a climate knowledge resource from C40 Cities Climate Leadership Group, designed for city practitioners, policymakers and anyone seeking practical guidance on urban climate action. Its purpose is to make the experience and advice of cities with established climate programmes accessible to cities everywhere, helping them understand proven solutions and emerging ideas and how to put them into practice.

The Hub brings together resources across key areas of city climate work, including emissions reduction, clean energy, climate adaptation, biodiversity, equity and climate finance. Visitors can explore policy briefs explaining why action matters and how to approach it, implementation guides offering practical steps, and case studies featuring ambitious, successful and replicable city initiatives. Data insights also help users explore city greenhouse gas emissions. Topics range from developing emissions inventories and transitioning away from fossil fuels to assessing climate risks, reducing flood risk and embedding inclusivity in climate planning.