Systemic vulnerabilities of the global urban-industrial network to hazards

Systemic impacts such as global supply chain failures can spread among urban areas through social and economic linkages. Urban vulnerability to hazards has been studied from the perspective of individual cities, but global vulnerability to systemic impacts at the network scale has not been assessed. Here we analyze the structure of global industrial supply chains as a lens to examine how impacts might spread across the global system of cities. We generate a novel urban risk network that describes industrial flows among 1686 urban areas. In contrast to the prevailing view of the global urban system dominated by the largest, wealthiest cities, we show that the functionality of the network is evenly spread across urban areas. These findings suggest that the network is more vulnerable to multiple simultaneous hazards than to singular impacts to urban areas with the highest nodal strength. We also find that clusters of the most strongly connected urban areas transcend administrative boundaries, increasing the possibility for systemic impacts to spread transnationally. These results illuminate the potential for linkages between city-scale vulnerabilities to climate change impacts and systemic vulnerabilities that emerge at the global network scale.