Engagement in sustainability planning is growing globally, yet we continue to see environmental conditions worsen. Much attention has reasonably been centered on capacities of national actors and policies, but corresponding issues of scale(s), space, and agency have been largely unaddressed. For example, scholars are just beginning to critically asses the interactive dynamics between state, private, and civic organizations in facilitating collective environmental action; the role of global decision-making in shaping local policy action; and the critical interface between urban and ecological spaces and flows. As a result, the complexities and possibilities of state/local agency, global networks, and spatial ecologies as a multidimensional system remain under-theorized. This is particularly important in a time of global ecologies, where worldwide processes now actively transform society and nature everywhere. This issue of Projections directly addresses this critical intersection of politics, globalization, and built and “natural” environments in this era of the Anthropocene. Our objective is to unearth the political and spatial dimensions of our environmental crisis, and to reassert the physical and environmental aspects of the study of urban politics and processes. The various articles included in this volume highlight key concepts and practices in sustainability planning that address the dynamic interrelationships of global urbanization, ecological change, and the emerging hybridities of society and nature.