Urbanization and urban areas are profoundly altering the relationship between society and the environment, and affecting cities’ sustainability and resilience in complex ways at alarming rates. Over the last decades, sustainability and resilience have become key concepts aimed at understanding existing urban dynamics and responding to the challenges of creating livable urban futures. Sustainability and resilience have also moved and are now core analytic and normative concepts for many scholars, transnational networks and urban communities of practice. Yet, even with this elevated scholarly attention, strategies for bridging between research and practice remain elusive, and efforts to understand and affect change towards more sustainable and resilient urban centers have often fallen short. This paper seeks to synthesize, from this issue’s papers and other strands of literature, the knowledge, theory and practice of urban sustainability and resilience. Specifically, we focus on what capacities urban actors draw on to create sustainability and resilience and how different definitions of these concepts intersect, complement, or contradict each other. We then examine the implications of those intersections and differences in the efforts by urban actors to enhance the capacity to change unsustainable trajectories and transform themselves, their communities, and their cities toward sustainable and resilient relationships with the environment.

Heat is the number one weather-related killer in the United States and indoor exposure is responsible for a significant portion of the resulting fatalities. Evolving construction practices combined with urban development in harsh climates has led building occupants in many cities to rely on air conditioning (AC) to a degree that their health and well-being are compromised in its absence. The risks are substantial if loss of AC coincides with a hot weather episode (henceforth, a heat disaster). Using simulations, we found that residential buildings in many US cities are highly vulnerable to heat disasters—with more than 50 million citizens living in cities at significant risk. This situation will be exacerbated by intensification of urban heat islands, climate change, and evolving construction practices. It is therefore crucial that future building codes consider thermal resiliency in addition to energy efficiency.