Most people assume that food comes from fields and farms. In reality, much of it comes from natural gas.

This uncomfortable truth lies at the heart of growing warnings about an oncoming food crisis. Modern agriculture does not simply depend upon sunshine, rain and fertile soil. It depends upon vast quantities of synthetic nitrogen fertiliser, produced using enormous amounts of energy. Remove that energy, and the food system itself begins to falter.

The invention of the Haber-Bosch process in the early twentieth century transformed the world. By extracting nitrogen from the atmosphere and converting it into ammonia, humanity was able to manufacture fertilisers on an unprecedented scale. Crop yields rose dramatically. Populations expanded. It is estimated that almost half the people alive today are fed because of synthetic nitrogen fertilisers.

Yet this apparent triumph concealed a dangerous dependency.

Ammonia production requires natural gas. Gas is both the raw material and the energy source. When energy prices rise sharply, fertiliser plants reduce output or close altogether because production becomes uneconomic. This happened during the recent energy crises, when fertiliser factories across Europe curtailed operations.

Senior figures in the industry issued stark warnings. The chief executive of one of the world’s largest fertiliser companies warned that the world was facing a food crisis. Others pointed out that half of global food production depends upon fertilisers that can no longer be taken for granted.

The chain of events is simple enough.

Energy shortages lead to reduced fertiliser production.

Reduced fertiliser availability leads to lower application rates by farmers.

Lower fertiliser use leads to lower crop yields.

Lower yields lead to food shortages and rising prices.

But there is another step in the chain that is too often ignored.

When food becomes scarce, those with money can continue to obtain it. Those without money cannot.

If governments simply allow the market to determine who eats and who goes hungry, scarcity falls most heavily upon the poor. Wealthier households may complain about rising prices, but they can often absorb them. Poorer households, already spending a larger proportion of their income on essentials, are forced to cut back. Nutritional quality declines. Meals are skipped. Hunger becomes concentrated amongst those least able to protect themselves.

History teaches this lesson repeatedly. Famines are not always caused by the complete absence of food. Often they arise because people lose the means to command food through the market. Scarcity becomes an issue of entitlement as much as supply.

This is one reason why rationing emerged in Britain during the Second World War. The purpose was not merely administrative control. It was to ensure that limited supplies were shared fairly and that the rich could not simply outbid the poor. The Ministry of Food recognised that shortages and uncontrolled prices would leave many people unable to obtain enough to eat. Orderly distribution at fair prices became a moral necessity as well as an economic one. Britain’s rationing system ensured that everyone received a basic entitlement and, in many poorer households, nutrition actually improved.

For most people in Britain today, the possibility of food rationing seems unimaginable. It belongs to black-and-white photographs and memories of another age. Yet if fertiliser shortages were severe enough to reduce harvests significantly, governments could once again face the same dilemma.

Without rationing, the poor suffer first.

With rationing, hardship is shared.

The remarkable fact is not that rationing might return. It is that a highly sophisticated society could once again be discussing it because of interruptions in the supply of natural gas.

This should force us to reconsider the assumptions upon which our food system rests.

Britain imports a large proportion of its food. Even domestic production relies heavily upon fossil fuel inputs, global supply chains and industrial methods dependent upon synthetic fertilisers. We have built a system optimised for efficiency under ideal conditions, but one possessing limited resilience when those conditions change.

Localism offers another way of thinking.

It does not promise complete self-sufficiency. Nor does it seek to abolish trade. Rather, it asks whether each locality should possess enough productive capacity, knowledge and organisation to weather disruptions beyond its control.

A localist Britain would encourage market gardens, allotments, orchards and smallholdings. It would support smaller farms serving nearby communities. Skills in cultivation, food preservation and seed saving would once again become ordinary parts of community life rather than specialist hobbies. Local food processing and distribution networks would complement national systems rather than disappear entirely.

No local system can eliminate every hardship. Yet local food production can soften the blow. A locality that retains productive land, practical knowledge and mutual obligation is less likely to see its poorest members abandoned to the impersonal logic of the market. Neighbours know who is struggling. Communities can respond before hunger becomes starvation.

Critics may dismiss such ideas as nostalgic. Yet dependence upon industrial fertilisers was itself an historical development. For centuries communities fed themselves using rotations, composting, animal manures and intimate knowledge of local conditions. Modern science has taught us much, but resilience has been sacrificed in pursuit of scale and efficiency.

The choice before us is therefore not between progress and the past. It is between vulnerability and resilience.

If the warnings prove exaggerated, stronger local food systems will still bring healthier communities, stronger local economies and a renewed connection between people and the sources of their nourishment.

If the warnings prove correct, and energy shortages do trigger fertiliser shortages, harvest failures and rationing, localities that have retained the capacity to feed themselves will face the future with greater confidence.

Food security cannot be left entirely to distant markets, fragile supply chains and the fluctuating price of natural gas. The ability to nourish a community is not merely an economic activity. It is one of the first responsibilities of any civilised society.

The coming food crisis, should it arrive, may teach us a lesson we have long forgotten.

The road from the gas field to the dinner table is far shorter than we imagine.

And the road back to resilience begins in the locality.