C40 is a network of mayors of nearly 100 world-leading cities collaborating to deliver the urgent action needed right now to confront the climate crisis. Together, we can create a future where everyone, everywhere can thrive.
What we do today will determine whether or not there is a thriving future for our communities, our cities and the natural world around us. We know that climate breakdown and rising inequality, compounded by the COVID-19 pandemic, require an unprecedented response to match the scale of the crises. That’s why C40’s mission is to halve the emissions of its member cities within a decade, while improving equity, building resilience, and creating the conditions for everyone, everywhere to thrive.
Mayors of C40 cities are on the leading edge of climate action, and are deploying a science-based and collaborative approach to help the world limit global heating to 1.5°C and build healthy, equitable and resilient communities.
C40 member cities earn their membership through action. C40’s most distinguishing feature is that it operates on performance-based requirements, not membership fees. C40’s Leadership Standards set the minimum requirements for all member cities and ensure the integrity of C40 as a network of climate leaders.