The food supply chain’s heavy reliance on electricity poses significant vulnerabilities in the event of prolonged and widespread power disruptions. This study introduces a system-dynamics model that integrates five critical infrastructures—electric grid, liquid fossil fuels, Internet, transportation, and human workforce—to evaluate the resilience of food supply chains to major power outages. We validated the model using the 2019 Venezuelan blackouts as a case study, demonstrating its predictive validity. We then explored how more extreme electricity losses would disrupt the supply chain. More specifically, we modeled the impact of a large-scale cyberattack on the US electric grid and a high-altitude electromagnetic pulse (HEMP) event. A cyberattack severely damaging the US electric grid and allowing for recovery within a few weeks or months would lead to substantial drops in food consumption. However, it would likely still be possible to provide adequate calories to everyone, assuming that food is equitably distributed. In contrast, a year-long recovery from a HEMP event affecting most of the continental United States could precipitate a state of famine. Our analysis represents a first attempt at quantifying how food availability progressively worsens as power outages extend over time. Our open-source model is made publicly available, and we encourage its application to other catastrophic scenarios beyond those specifically considered in this work (for example, extreme solar storms, high-lethality pandemics).

To combat global warming, energy systems are transitioning to generation from renewable sources, such as wind and solar, which are sensitive to climate conditions. While their output is expected to be little affected by global warming, wind, and solar electricity generation could be affected by more drastic climatic changes, such as abrupt sunlight reduction scenarios (ASRSs) caused by nuclear war (“nuclear winter”) or supervolcanic eruptions (“volcanic winter”). This paper assesses the impacts of an ASRS on global energy supply and security in a 100% renewable energy scenario. National generation mixes are determined according to roadmaps for a global transition to renewable energy, with wind and solar contributing a combined 94% of the global energy supply. Wind and solar generation are determined for a baseline climate and an ASRS following a large-scale nuclear exchange. While effects vary by country, overall wind and solar generation are expected to reduce by 59% in the first year following an ASRS, requiring over a decade for full recovery. Ensuring sufficient energy for everyone’s critical needs, including water, food, and building heating/cooling, would require international trade, resilient food production, and/or resilient energy sources, such as wood, geothermal, nuclear power, tidal power, and hydropower.

Nuclear war poses catastrophic risks not only through its immediate effects and potential nuclear winter, but also through the disruption of industrial production on which modern civilization depends. In this study we estimate the reduction in global industrial output following a US-Russia nuclear war, as well as a more limited India-Pakistan exchange, by combining geospatial analysis with historical evidence of how localized industrial losses propagate through supply chains. A bilateral US-Russia nuclear war could destroy 3% of global industrial infrastructure, with cascading effects potentially reducing global industrial output by 25%. If high-altitude electromagnetic pulse attacks occur, the disruption to global industry could be even more severe, though such effects remain poorly understood. These disruptions would severely impair humanity's ability to meet basic needs and adapt to other nuclear war effects such as nuclear winter.

Nuclear war could inject millions of tonnes of soot into the stratosphere, cooling the Earth and devastating crop yields. We assess crop relocation—switching which crops are grown where—as an adaptation strategy. Using the Mink crop model, we simulate six major crops under three nuclear winter scenarios (16, 47, and 150 Tg of soot). Without adaptation, global caloric production falls 23%, 53%, and 85% respectively during the worst year of each scenario. We find that mild cooling scenarios favor expanding high-calorie warm-season crops like rice and maize, while severe scenarios require extensive conversion to cold-tolerant crops like rapeseed. In the extreme 150 Tg scenario, crop relocation could double food production compared to current planting patterns. While insufficient to prevent widespread famine in severe scenarios, crop relocation has the potential to save billions of lives.

An abrupt-sunlight-reduction scenario combined with a catastrophic collapse of electricity/industry has the potential to disrupt food production and distribution worldwide, creating widespread food insecurity. This paper explores the potential of animal draught power to cultivate current cropland and expand cropland area in each country with winter wheat during an abrupt-sunlight-reduction scenario with global collapse of industry. For a 150 tera-gram soot injection with no fertiliser application, the country-level allocation of draught animals allows for the global cultivation of over 700 million hectares (Mha) of current cropland, and expansion of global cropland area by 120 Mha, mostly focused in tropical regions of the globe. Over the course of seven years, over 8.3 billion tons of wheat are produced globally, 25% of which is fed to working animals, while the remaining surplus is used to meet human calorie demand. Although enough wheat is eventually produced to meet 80% of the human global calorie demand, animal demand and trade collapse only makes it possible to meet 30% of the global calorie demand. This presents outdoor agriculture and cropland expansion as viable and sustainable methods to mitigate starvation and prevent animal extinction in a catastrophe in some select countries.