As the federal government failed to take ambitious action to limit climate change in the early 21st century, many cities in the US pledged to step into the void. Networks of city governments and philanthropists offered support and cities invested their own resources in sustainability offices. However, cities made limited progress in reducing their greenhouse gas emissions in the first two decades of this century. Local Greens provides a clear-eyed analysis of the potential for big city governments to address society's most pressing environmental problems in the near term. Through original case studies of New York's environmental policy efforts in the early 21st century, the book examines the promise and perils of turning to cities to tackle climate change. Drawing on an analysis of cities' strengths and weaknesses, the book outlines a high-level agenda for urban environmental policy for a sustainable future.