That risks nuclear war.

Widespread and consistent access to food makes it possible to live in a stable society. Without this guarantee, the incidence of political instability and war tends to increase. There is an emerging body of evidence that food crises can initiate political instability5,6,7, increasing the risk of conflict through various means, such as a decay in the ability of a state to govern its people.8

In one recent example, the severe drought that struck Syria between 2007 and 2010 contributed to massive crop failures that undermined livelihoods and forced 1.5 million people from rural areas into cities, exacerbating existing social stresses.9 Though the drought was clearly not the primary cause of the Syrian Civil War, it contributed to a regional refugee crisis that spilt over into Europe, and had profound effects on the politics of countries across the region, which are still playing out today.

Even minor shocks to the food supply can have severe consequences. From 2006 to 2008, large maize-exporting countries like Brazil, Argentina and Ukraine imposed export bans, which together with droughts and rising oil prices precipitated a price spike of 83%, causing economic instability and social unrest across much of the developing world.10 Such price volatility in food disproportionately affects the approximately 800 million people living in extreme poverty.11

Political instability is most dangerous when it occurs in countries with access to weapons of mass destruction. Should a food crisis arise in one of these countries occur that results in civil war and governmental collapse, these weapons could end up in the hands of a group that intends to use them maliciously as an act of terror. The fact that Pakistan (which has access to nuclear bombs) and Iran (considered capable of producing bioweapons) are ranked the 25th and 44th most fragile states in the world is cause for concern that food insecurity in those regions could have severe consequences.12

Risks of total food production loss

When Indonesia’s Mount Tambora erupted in 1815, dark volcanic dust and reflective sulphate aerosols thrust into the skies are thought to have lowered global temperatures by 1°C. The United States experienced snowfall in summertime and China, North America and Europe suffered crop failures and ensuing famines.13 We could easily see such effects again in future after a sufficiently large volcanic eruption or even a small-scale nuclear exchange.

There is some evidence from climate science that indicates it would take the detonation of only 50-100 nuclear weapons in populated cities to lift millions of tonnes of combustible material into the atmosphere and trigger what is known as nuclear winter, sharply lowering global temperatures over a decade.14,15 Summer temperatures would drop by more than 20°C over much of North America and Asia, and would stay continually below freezing for several years in the mid-latitudes, where most of our food is produced. Such drastic changes to the climate have the potential to bring food production to a near-complete halt, leaving billions at risk of starvation.

While we’d lose almost all of our regular food production, it’s likely there would be some food production via cold-tolerant crops and alternative foods such as seaweed and algae. Some human populations would likely survive, though in a vastly different world. The ability of surviving populations to recover an equivalent level of civilization is unclear.16,17 (See also our page on risks from nuclear war.)

Catastrophes such as this that result in (near or) total food production loss pose the most severe risks to global food production. The likelihood of such a total food production loss scenario is dominated by the anthropogenic risk of nuclear winter, with the natural risks like supervolcanoes or asteroid impacts having similar effects but being far less likely. Estimates of a total food production loss scenario vary between 1-10% this century, with a risk of human extinction of approximately 0.1%.

Risks of significant food production loss

Risks of significant food production loss are those that could result in a 3-30% reduction in our food production capacity. While this might sound much less extreme by comparison, keep in mind that all disasters in living memory have been less than a 3% loss. Based on current research18, there is an approximately 80% chance of significant food production loss this century. Sources of such risks include:

Global warming resulting in multiple bread-basket failure19;

Catastrophic crop disease to staple crops – the grass family poaceae (which includes wheat, rye, and barley) alone contributes 50% of the world’s calories20,21;

A severe pandemic – pandemics can impact global trade systems, limit movement of agricultural workers, and decrease affordability of food. The ebola virus resulted in a significant reduction in regional food security22, while COVID 19 had impacts on global trade and buying power of global poor.23

Loss of pollinators – in Europe, pollination services represents some 12% of food production, mainly by increasing the yield of fruits, vegetables and nuts.24 Global agricultural losses are estimated at between 3-8% in the event insect pollination were to fail.25

There are also risks of significant food production loss that would occur via failures of the physical infrastructure needed to produce food. We rely on a complex network of interlinked infrastructure – e.g. electricity, fossil fuels, water, telecommunication, etc – to run the industrial systems which provide the goods and services we consume daily. Food production, which has become increasingly industrialized since the 20th century, is highly dependent on the proper functioning of these systems. This is exemplified by modern agriculture’s reliance on synthetic fertilizers. An estimated 40-50% of the world’s population survives on food produced from fertilizers made through the Haber-Bosch process26, which requires gas (fossil fuel) and electrical infrastructure as well as transportation networks to distribute.

Infrastructure is vulnerable to various low probability high impact events such as High Altitude Magnetic Pulse (HEMP)27, space weather (solar storms or coronal mass ejections)28,29,30, pandemics31, and coordinated cyber-attacks.32 Such events could result in major impacts on food systems.33

Conclusion

Food insecurity is a global catastrophic risk factor increasing the likelihood of other catastrophes occurring (e.g., nuclear war) or decreasing our resilience to catastrophes. Even if no catastrophe results from prolonged food insecurity, such significant food system failures would be robustly bad, potentially causing hundreds of millions to die. The complex nature of food security and the highly interdisciplinary nature of the problem, makes it a difficult problem to address.