Background

City regions are a major proposed site for sustainably intensifying agricultural production to meet global food needs in the 21st century. Greater investment in localizing city region food systems—combining food production in cities and their peri-urban landscapes—promises to shorten supply chains and reconnect producers with consumers, improving socio-ecological sustainability and resilience. Sustainable urban agricultural intensification (UAI) is likely to entail greater use of technologies that decouple food production from environmental constraints including seasonal climates and available land base. Proposed technological systems range from capital-intensive approaches such as vertical farms, which fully control the growing environment, to more knowledge-intensive approaches such as urban agroecology that balance environmental modification with crop diversity and agronomic adaptation. Researchers have begun to question the relative resource requirements, environmental footprints, and productivity of these production systems in terms of energy and land-use intensity, life cycle impacts, and yield. While conducting sustainability assessments for different food production systems along different dimensions is critical, another major gap remains: comparatively evaluating the equity and justice implications of different pathways toward a sustainable city-region food system.