All we need to do to address our food insecurity is learn to better preserve food after it has been harvested. However, the technology we rely on to do that comes at a great cost. We need to find an alternative approach - one that prevents spoilage without harming the environment.

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Paul Ehrlich’s 1968 bestseller, The Population Bomb, opened with an apocalyptic vision of humanity’s near future:

“The battle to feed all of humanity is over. In the 1970s, hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.”

Few have been more wrong.

Today, we produce more than enough to feed every person on the planet, and if we still have food insecurity in some corners of the planet, it is because we haven’t yet learned to deal with spoilage. If we can preserve all the food we produce till it gets to those who need it, we will easily be able to feed the millions who still go hungry.

That we cannot, despite the technological progress we have made, is one of the tragedies of the modern age.

Preservation

Freshly harvested food has a limited lifespan. Take vegetables, for example. From the moment they are separated from the roots and leaves that provide them with water and energy, they turn upon the stores of energy within their cells in a cannibalistic attempt to keep their cell metabolism going.

However, it doesn’t take more than a few hours before they burn through most of these stores, weakening their external defences. This is the opening that bacteria and other microbial organisms need to launch an attack on them and those stores of energy. Within days, fungi cover them completely, overwhelming their defences and consuming them entirely.

For millennia, human beings have used different techniques to preserve food so that it can survive after it has been harvested. We have pickled, salted, cured, and chemically treated it, ever walking the fine line between preserving nutrients and ensuring that it remains edible. Of all the techniques we have deployed, by far, the most effective has been refrigeration.

Low temperatures slow the growth of microbes. It makes them sluggish, delaying the decomposition they bring about. It places food in a state of suspended animation that allows it to retain its freshness for longer than would otherwise have been possible. While we have known about the preservative properties of the cold for centuries, it is only relatively recently that we’ve been able to deploy it reliably at scale.

Refrigeration

In her book Frostbite, Nicola Twilley describes the evolution of this technology and how we used it to limit spoilage. She describes the massive modern cold chains we depend on for everything we eat today, pointing out that it is thanks entirely to these cold-storage facilities (artificial cryo-spaces so large that, if aggregated under one roof, they would create a third polar ice-cap) that we are able to sustain our massive urban populations. This, in turn, makes it possible for food to be cultivated at great distances away from where it is ultimately consumed and safely make the long journey from the farm to the fork. But for this, modern cities simply could not exist.

As impressive as all of this sounds, these preservation successes conceal deep inequities. Most of the world’s cold chains cater to the needs of the developed world. They are devoted to ensuring that restaurants and supermarkets in the Global North are stocked with more than they can consume. In developing countries, where most of the world’s hungry live, there are far fewer such facilities.

As a result, between a third to half the food that they produce spoils before it gets to those who need it. If we want to find a solution to the challenge of global hunger, this is the essential problem we need to solve. We need to find a way to prevent the food that these countries produce from spoiling before it gets to the plates of those who need it.

Cold Comes at a Cost

Based on what has worked so far, one might think the answer is to build cold chains similar to those that sustain the Global North. There is, however, one additional factor to consider. Refrigerating equipment currently accounts for more than 8% of global electricity usage and cold-storage companies are, as a class, the third highest industrial consumers of power in the world. While the refrigerants used in these systems are much safer than they used to be, if they leak into the atmosphere, they can have a much greater impact on global warming than carbon dioxide. If we are going to build more cold chains to solve the global hunger crisis, we must acknowledge that this will come at a significant cost to the climate.

Despite the success of refrigeration, we haven’t stopped experimenting with other preservation techniques. As a result, there are a number of other post-harvest solutions for extending the consumable life of fruits and vegetables.

For instance, Apeel Sciences has developed a nanoscale coating that is so precisely permeable that it slows down the passage of oxygen, carbon dioxide and water vapour into and out of harvested fruits and vegetables so that they breathe as slowly as possible while remaining hydrated. This retains essential moisture inside the harvested produce while keeping harmful oxygen out. In laboratory conditions, this solution has been shown to quadruple shelf life, preserving produce as well as current refrigeration techniques.

We may have reduced temperatures to slow down the normal pace of decomposition for over a century-and-a-half, but that is not the only way to keep things fresh. If we are to achieve our goal of ending food insecurity while protecting the planet, we need to think beyond building more refrigerators and better freezers.

We need to focus on designing smarter surfaces.