Most American environmental law scholarship overlooks the role of cities in environmental law and policy. Instead, scholars typically focus on federal environmental law. This book emphasizes the potential for leading cities to play a meaningful role in protecting the environment. It offers a framework for understanding the factors that give to, and constrain, local environmental law and policy. Local environmental policy may emerge from the top from local elites centrally concerned with local economic development, and from the “bottom up” from community groups. However, there are limits on the costs that local governments can impose on local actors to address global environmental problems, such as limiting climate change, given the overriding importance that local governments attach to promoting economic development. The book offers case studies of local environmental efforts in New York City to illustrate the promise and limitations of local environmental policy. Taking into account the opportunities and constraints at the local level, the book outlines a high-level agenda of actions that local governments in large cities should undertake to adapt to climate change and contribute to decarbonization.