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Cambridge Global Food Systems

An Interdisciplinary Research Centre at the University of Cambridge
 
Strait of Hormuz

The war in Iran has had significant impacts on economies and markets, including the global food system. Notably, the effective closure of the Strait of Hormuz is causing short-term shortages and price spikes as well as longer-term effects for farmers and food producers. Whilst the damaging impacts are serious for those affected and require immediate responses, the exposure of the fragility of the global food system to geopolitical shocks (as already shown by Covid-19 and the war in Ukraine) can also be an opportunity to pivot towards a more sustainable food system characterised by shorter supply chains, a decreased reliance on vulnerable fossil fuels and the growth of regenerative agriculture.

Here, three members of the University of Cambridge’s Global Food System Interdisciplinary Research Centre offer their perspectives.


From Intensive to Regenerative Agriculture
Professor Lynn Dicks, Professor of Ecology, Department of Zoology

Shocks that sharply increase fuel and fertilizer prices, as we are currently seeing in response to the war in Iran, have major impacts on farm businesses, especially those growing intensive, fertilizer-hungry arable crops like wheat and barley. Here in England, margins in farming are narrow, with 21% of farms unprofitable according to 2024-25 Government statistics. Young people are leaving the industry, due to the uncertain future and the real challenges of making a living in food production. This is not good for our national food security.

The last time there were huge spikes in oil prices was following the Russian invasion of Ukraine in 2022. Our research with farmers in the H3 project demonstrated that the high, volatile input prices were a key factor in persuading English farmers to move towards regenerative agriculture more quickly than they might otherwise have done (Beacham et al 2023).

One farmer described how his fertilizer costs had risen from £675/tonne to £750/tonne overnight in February 2022, compared to a price of £275/tonne the previous year. Another told us he was spending c.£60–70,000 a year on diesel and saw the move to direct drilling—which avoids ploughing and disturbing the surface of the soil as much as possible—as an opportunity to halve this diesel consumption.

Four years later, our data provide clear evidence (not yet published) that English farmers who follow a more regenerative system are not only benefiting the health of their soil, they also use a lot less fuel and less synthetic fertilizer, making them economically more resilient to price shocks.

So, the shift to regenerative agriculture has double benefits for the UK economy. It improves the health of our soil, a key natural capital asset of great value and importance for adapting to climate change (see State of Natural Capital Report for England, Lusardi et al 2024). It also cushions us from food security threats created by dependence on fuel and fertilizer imports from unstable regions of the world.


From Fossil-fuel to Green Fertilizer
Dr Collin Smith, Postdoctoral Research Associate, Department of Chemical Engineering and Biotechnology

The disruption in supply chains of essential chemicals such as ammonia-based fertilizer due to closing of the Strait of Hormuz is once again highlighting the need to transform the chemical industry toward sustainability and robustness. Around one third of the global ammonia-based fertilizer trade passes through the Strait and much of the LNG export is similarly destined for ammonia production outside the Middle East, thereby critically endangering global food production. Additionally, the ammonia production facilities in the Persian Gulf are enormously complex and integrated systems which are not trivial to restart or operate flexibly under vacillating export market, indicating that fertilizer markets will continue to be negatively affected even after traffic flows again. 

Sustainable “green” ammonia from water, air and renewable energy provides the opportunity not only to transform the global fertilizer industry to a robust network of distributed production facilitates located where renewable solar and wind are available, but also to decarbonize an industry responsible for ~2% of global CO2 emissions. In this effort, the UK and Europe have an essential role to play in delivering low cost green ammonia using the plentiful wind resources in the North Sea and solar resources around the Mediterranean. 


From Fragile Supply Chains to Sustainable Defaults
Professor Lucia Riesch, El-Erian Professor of Behavioural Economics and Policy, Judge Business School

From a behavioural food-policy perspective the effective closure of the Strait of Hormuz is not just a geopolitical shock but a disruption to the choice environment of the global food system. When commercial shipping is constrained, food importers are forced to reroute essential goods. Additionally, the disruption of this chokepoint increases the cost and reduces the availability of fertilizer, feed, and energy because the strait is central to global oil, gas, and fertilizer trade.

Viewing actors in the long and complex value chains of global food systems through a "behavioural lens" helps explain why this matters for food security: during periods of price spikes, felt insecurity, and potentially growing scarcity of options, households, producers, retailers, and public procurers tend to revert to available, cheaper alternatives. This can be both a loss and an opportunity for change towards more resilient and sustainable food systems in the UK and worldwide. One quick and robust behaviourally informed policy approach is to redesign defaults and incentives to promote less input-intensive diets, increase plant-based diets, and, importantly, reduce food waste. Over time, these policies must be supported and strengthened by structural and institutional systems, such as rethinking subsidies and taxes, strengthening regenerative and agro-ecological farming, circularity, and more localized or re-shored supply chains, especially in contexts like the UK.

Avoiding food waste and loss, and shifting diets towards more plant-based and energy-frugal diets, helps reduce dependence on imported feed and synthetic fertilizer, and on distant maritime chokepoints.

Author Information

Professor Lynn Dicks, Professor of Ecology, Department of Zoology
Professor Lucia Riesch, El-Erian Professor of Behavioural Economics and Policy, Judge Business School
Dr Collin Smith, Postdoctoral Research Associate, Department of Chemical Engineering and Biotechnology