Risk of simultaneous food shocks to cities increases with supply chain vulnerability to droughts

Global warming exacerbates agricultural production losses from extreme climate events with cascading impacts along supply chains that affect cities. However, little is known about cities’ vulnerability to climate-related food supply shocks. Using data-driven and network-based approaches, we determine the vulnerability of cities in the United States to domestic drought-related food shocks. Our vulnerability framework integrates key traits of a social-ecological system’s response to hazards: resilience, exposure, and sensitivity to disruption. We find that vulnerability varies considerably across cities, with western cities showing higher vulnerability than eastern cities (56% versus 47%; p < 0.001). It tends to be high in western cities because of high supply chain exposure to water stress and high urban food insecurity. Moreover, we find that southern cities show higher vulnerability than their northern counterparts, primarily due to disparities in food insecurity. Using the unprecedented 2012 U.S. drought as a case study, we show that high-vulnerability cities are associated with a higher risk of simultaneous food shocks and greater food supply losses than low-vulnerability cities. Our vulnerability framework can help inform climate adaptation interventions for food system security in urban-rural interactions.