C40 CITIES

C40 is a network of nearly 100 world-leading mayors working together to take the immediate action needed to address the climate crisis.

They can build a future where everyone, everywhere thrives if we work together.


What they do now will determine whether our communities, cities, and the natural world around us have a bright future. We know that the COVID-19 pandemic, combined with climate breakdown and rising inequality, necessitate an unprecedented response to match the scale of the crises. C40's mission is to halve emissions in its member cities within a decade, while also improving equity, building resilience, and ensuring that everyone, everywhere can thrive.


C40 city mayors are at the forefront of climate action, using a science-based, collaborative approach to help the world limit global warming to 1.5 degrees Celsius and build healthy, equitable, and resilient communities.