Cascading disruptions in natural gas, fertilizers, and crops drive structural food supply vulnerabilities globally

Global food security depends on tightly coupled international supply chains including natural gas, mineral fertilizers, and staple crops. Earlier research has examined potential consequences of disruptions in each of these domains separately but not from a systemic perspective. Here we integrate bilateral trade in natural gas, nitrogen, phosphorus and potassium fertilizers, and eleven staple crops accounting for approximately 70% of plant-based calories into a cascading-impact model spanning 208 countries, 20 geopolitical blocs, and the period 1992-2023. Under complete trade isolation, up to 22% of global caloric consumption would be lost, with a peak in the most recent evaluated years. Structural vulnerabilities vary greatly. Regions largely lacking some parts of the supply chain face near-total crop supply collapse, while few countries can cover the whole nexus through domestic resource endowments and production capacities. Temporal trends highlight a substantial increase in vulnerability globally, most prominently in the EU with a near two-fold increase since the 1990s. Market power is most concentrated and most volatile in the upstream gas and mineral-fertilizer layers, from which shocks propagate downstream. Food stocks provide only limited resilience with half of humanity living in countries disposing of stock lasting less than three months. Our results identify the upstream supply chains as the structural bottlenecks of the global agrifood system and propose leverage points to enhance resilience.