HMN 2026: How Global food shock model reveals self-sufficiency alone may not prevent crises

Global food systems are fragile. Recent shocks such as the closure of the Strait of Hormuz and the Russian invasion of Ukraine have raised prices and exacerbated food insecurity. Governments are increasingly trying to shield themselves from future food crises, whether caused by conflict, climate shocks, disruptions to global trade or failed harvests.

But new Oxford-led research appearing in PLOS Climate suggests that many countries may be focusing on the wrong kind of resilience. The findings challenge food-security strategies that focus mainly on increasing domestic food production while overlooking their dependence on shocks to production abroad and energy supplies. The conclusions are particularly relevant for countries such as the UK, where recent debates over food security have focused on improving self-sufficiency.

How global shocks spread through systems

The analysis, titled “Assessing the Resilience of Global Grain Supplies to Compound Climatic and Non-Climatic Shocks,” found that spikes in energy and fertilizer prices, such as those caused by the wars in Ukraine and Iran, can rapidly spread through global food systems because modern agriculture depends heavily on fuel, fertilizer and transport. Export bans and transport-related disruptions also caused severe regional impacts.

Countries reliant on a narrow group of suppliers and holding low grain reserves were often hit hardest during severe global shocks. Extreme weather and poor harvests pushed food prices up by as much as 50% to 100% in some countries, depending on how exposed and diversified their food systems were. By contrast, countries with more diverse suppliers and flexible trade networks were better able to switch suppliers and cushion the impact of crop failures.

Why diversity and flexibility matter

Jasper Verschuur, lead author and Research Associate at the Environmental Change Institute, University of Oxford, said, “No country can build a fortress against global food shocks. And producing all food within your own borders is unfeasible for many countries, and leaves them exposed to the vagaries of their weather. Countries with diverse suppliers, reserves and more flexible trade networks are often far better placed when crises hit.”

The study highlights the importance of stress-testing the global food system, and the work has developed a model which allows multiple simultaneous shocks to be analyzed. In the most severe compound-shock scenarios, where poor harvests collided with wars, trade disruption and energy shocks, almost every country in the world experienced food-security losses simultaneously, though the impacts were distributed unevenly.

Professor Jim Hall, Director of the Oxford Martin Systemic Resilience Initiative at the University of Oxford, said, “The real danger comes when shocks compound. A poor harvest, war or spike in fertilizer prices can now ripple rapidly through global trade networks and raise food prices far beyond the countries where the disruption began. What matters is not just how much food a country produces, but how prepared it is for instability.”

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