The inaction of nation states and international bodies has posed significant risks to the environment. By contrast, cities are sites of action and innovation. In Sustainability, Citizen Participation, and City Governance, contributors researching in the areas of law, urban planning, geography, and philosophy identify approaches for tackling many of the most challenging environmental problems facing cities today. Sustainability, Citizen Participation, and City Governance facilitates two strands of dialogue about climate change. First, it integrates legal perspectives into policy debates about urban sustainability and governance, from which law has typically stood apart. Second, it brings case studies from Quebec into a rare conversation with examples drawn from elsewhere in Canada. The collection proposes humane and inclusive processes for arriving at effective policy outcomes. Some chapters examine governance mechanisms that reconcile clashes of incommensurable values and resolve conflicts about collective interests. Other chapters provide platforms for social movements that have faced obstacles to communicating to a broad public. The collection’s proposals respond to drastic changes in urban environments. Some changes are imminent. Others are upon us already. All threaten the present and future well-being of urban communities.