Urban density can actually create the possibility for a better quality of life and a lower carbon footprint through more efficient infrastructure and planning.

City mayors are directly accountable to their constituents for their decisions, and are more nimble than state and national elected officials to take decisive action—often with immediate and impactful results. What our cities do individually and in unison to address climate change can set the agenda for communities and governments everywhere.

Collaboration between C40 Cities is

working—right now.

C40 is making a significant difference in improving the scale and speed of climate action, with 30% of all climate actions in C40 being delivered through city-to-city collaboration. When C40 Cities choose to take action on adaptation and mitigation strategies, and share knowledge with one and other, the collective impact is huge.

Today, nearly 10,000 climate change actions are in effect in C40 Cities, with over 78% of actions reported in 2015 planned for expansion.