As national governments and global institutions fail to address climate change, an increasing number of cities have committed to major sustainability and climate strategies. Why do some cities take bold action while others remain on the sidelines? Christof Brandtner shows that city climate action is not simply a matter of political will: It is an organizational problem. Cities do not act alone. They are embedded within both a broad institutional superstructure of professional networks and peer cities as well as a deep organizational infrastructure of civil society organizations, public agencies, and socially responsible firms. This dual embeddedness shapes cities’ capacity to plan, learn, lead, and scale sustainability solutions. Drawing on comparative research spanning fifteen years and thousands of cities around the world, Brandtner traces how environmental strategies, sustainability practices, and green building initiatives emerge, diffuse, and take hold. He uncovers the structural conditions that enable and inhibit meaningful climate action, revealing why it varies so widely across cities. By combining lenses from urban theory and organizational sociology, Cities in Action sheds light on how cities navigate their social and institutional environments to meet the climate challenge. This book offers a novel perspective for scholars, policy makers, and practitioners seeking not just to explain but also to empower city action. At a time when political will seems overmatched by global climate change, Cities in Action offers a rigorous, empirically rich, and ultimately hopeful analysis. Bringing together urban studies and organizational theory, Christof Brandtner elegantly reconstructs how global networks of cities are mutually embedded with local actors and organizations in ways that sustain aspirations, elicit action, and generate innovation. Necessary, inspiring, eye-opening reading. -- Elisabeth S. Clemens, author of Civic Gifts: Voluntarism and the Making of the American Nation-State This pathbreaking book shows what scholars can learn if we conceive of the city as an actor, not just a stage. Cities in Action offers both a rigorous empirical analysis of how urban regimes take on the climate crisis and an original theoretical framework for studying cities as open systems of organizational networks that touch and interpenetrate. One of the most exciting works of urban studies I’ve read in years. -- Eric Klinenberg, Helen Gould Shepard Professor in the Social Sciences, New York University A sharp-eyed and engaging theorization of the connection between cities and organizations, showing us why some cities innovate and improve while others do not. Brandtner's central concept of the "dual embeddedness" of cities in local organizations and institutional demands means this is required reading for both urban and organizational scholars, who should never again ignore each other. -- Nicole P. Marwell, coauthor of Mismeasuring Impact: How Randomized Controlled Trials Threaten the Nonprofit Sector Surprisingly, cities have become important loci of sustainability policy and practice. This impressive book reviews this development and presents sophisticated analyses of the internal and external organizational structures that explain why this happens. It is a real contribution to organizational theory and will especially interest those concerned with sustainability. -- John W. Meyer, coauthor of Institutional Theory: The Cultural Construction of Organizations, States, and Identities Christof Brandtner is associate professor of social innovation at EM Lyon Business School, a CIFAR Fellow, and cofounder of the Civic Life of Cities Lab.