As countries negotiate the next climate agreement, due in December 2015 at the Paris COP 21, there is growing attention to the actions and initiatives that non-state and sub-state actors – including cities, regions, private companies, countries, and civil society groups – play in mitigating and adapting to climate change.  Their contributions have the potential to help raise national ambition; spur additional mitigation, adaptation, and finance action; and inject an emphasis on action and solutions into the public dialogue on climate change.

The core research question of this paper asks, “When scaled up to national and global scales, what is the potential of sub-national action to impact larger climate goals?” While individually these sub-national actions may not seem significant, the goal of this analysis is to demonstrate the potential for sub-national climate actions to contribute towards, accelerate, and raise the ambition of national efforts on climate change. At scale, the aggregate impact of sub-national climate actions and innovations could be substantial.