Transformational climate actions by cities

With their predominantly coastal geographies, rapidly growing populations, and emissions-intensive activities, cities are highly vulnerable and major contributors to climate change. Their role as cultural centers, and commerce and innovation hubs, means they are also promising sources of solutions. Taken together, these factors demand a closer examination of the progress and solutions that cities are making to mitigate climate change and adapt to its impacts. However, research on the extent and effectiveness of cities' implementation efforts is underdeveloped. There is a need to better understand if and how cities are rolling out effective implementation measures, what effects (intended and unintended) such measures are having, and whether their implementation efforts are achieving the transformational changes needed to realize a low carbon, climateresilient future. This editorial introduces the special issue by exploring these issues and reflecting perspectives from a variety of disciplines both within and outside academia, and in relation to diverse cities in the Global North and South. To better understand the practical dimensions of implementation, and the various obstacles and opportunities faced by public and private sector actors in progressing climate action targets and goals, the editors invited submissions reflective of co-produced research. Though not all took this form, some did and helped to foreground the experiences of those actors who arguably have the most power and responsibility to advance implementation measures, and seed the very institutional arrangements needed for deeper, multisectoral climate action. Collectively, the content of the special issue points to a need for significant investment, policy change, social innovation, and cooperation across societal scales.