Introduction to Resilient Foods

From famine foods to science fair projects

Last week we looked at the potential realities of a nuclear winter. If you skipped last week’s article, I’ll summarize the effects here: dark, devastating, and deadly.

Unsurprisingly, such findings have encouraged researchers to start thinking about ways humanity could survive a catastrophe like this. The expected temperature drop is not enough to threaten human life under average circumstances, but it is enough to threaten global agriculture, and some have estimated there could be two billion or more deaths from famine alone in the event of a nuclear winter. As long as nuclear weapons exist,¹ we’ll have need of contingency plans for their usage.

This brings us to a new subfield of research: resilient foods.

According to Baum, a resilient system is “able to retain critical functionality in the face of disruptions, even while it may make adaptations of noncritical attributes.” Therefore, resilient foods are "those foods, food production methods or interventions that would allow for significant food availability in the face of a global catastrophic food shock” (Pham et al.). How do you feed the world when agriculture, infrastructure, and the comforts of civilization would be transformed potentially beyond recognition?

Figure from Wilson, Payne, & Boyd, “Food Supply During Nuclear Winter.”

Traditional resilient foods

Some foods are naturally more resilient to cold temperatures than others. This is probably already intuitive — after all, just like you wouldn’t go to Alaska to find citrus fruits, not all foods can grow in the tropics, either. These cool-weather crops include potatoes, carrots, cabbages, sugar beets, and peas, among others, as you can see in the table above.

Other plants can withstand lower average temperatures, but would need to be relocated out of their usual ranges due to rapid global cooling. These relocatable crops include grasses like wheat and barley, as well as other members of the brassica genus such as canola.

In some cases, you can also artificially increase growing temperatures through the use of greenhouses, although it is unlikely that this will contribute enough to growing conditions to overcome the below-freezing temperatures and limited light in certain areas. With greenhouses, you might be able to continue growing staple crops like rice, corn, and soybeans, although Pham indicates that building a significant number of greenhouses would require between 6 and 12 months. This also requires the mobilization of construction materials, requiring at least minimal supply chain operations, and it remains unclear how likely these would be to remain functioning under such stressful conditions.

Other resilient foods that might immediately come to your mind include mushrooms and insects. However, neither of these are optimal calorie producers. Mushrooms have a fairly low energy content compared to their production costs, meaning widespread availability in a crisis at any significant volume is unlikely. Most insects are similar, being costly to farm and a net calorie sink, meaning you have to spend more calories feeding them than you get back out by eating them. It’s possible that scaling the production of certain edible insects which can digest cellulose, which humans cannot digest, might be a worthwhile investment. Examples include mealworms and termites.

Animal Products

Part of optimizing human survival in nuclear winter involves putting the brakes on animal agriculture; like insects, animals are net calorie sinks, and do not give us as much energy as we put into them. The caloric conversion (i.e., the number of calories we gain from eating an animal compared to how many calories it takes to feed it) is less than 20% and sometimes as low as 3%.

Ruminants, like cows, sheep, and goats, are also able to eat and digest things that humans aren’t able to eat. Agricultural residues contain a lot of energy, trapped in forms that human digestive systems aren’t able to access, like cellulose. Devoting these materials to raising dairy cows and goats, rather than cows raised for meat, would be up to six times as energy efficient and could provide a valuable source of dietary fat in an otherwise scarce scenario.

Meat, including offal and fish, would decline drastically and surge in price after the first few months of nuclear winter. Aquatic food chains would slowly deteriorate and possibly collapse during low light periods as a result of reduced capacity for photosynthesis. Some experts anticipate a brief period of widespread availability of animal meat and organs at the beginning, as farm animals are culled en masse.

As a historical example of this behavior, Xia looks to historical precedent in New England in 1815, the Year Without a Summer, to support her No Livestock scenario, where meat and animal product production, including aquaculture, breaks down after a year as crops are redirected towards human consumption.

Figure from Baum et al. “Resilience to global food supply catastrophes.”

Alternative Resilient Foods

There are a few underexplored food options that aren’t quite on our plates yet, but might be great sources of nutrition in the event of a nuclear winter.

Macroalgae, such as seaweed, are uniquely positioned to expand its presence in our culinary profiles in the event of nuclear winter. Since it grows underwater, it can thrive in low-light conditions and is protected from UV damage. It does not compete with terrestrial agriculture for resources, needing no fresh water, land, or pesticides. Seaweed is incredibly fast-growing, easily scalable, and has been advocated for by the Food and Agriculture Organization for decades. Since it’s not very technologically intensive, needing only ropes for the seaweed to grow on, and some quaint boats to harvest it, seaweed could be scaled up as a food source in as little as six months after the disaster. Spirulina, a type of algae, has been consumed by societies around the world since prehistory, and is also being explored as a source of nutrition for astronauts in space.

Leaf protein concentrate is exactly what it sounds like. By pulping and compressing leaves from a variety of possible sources, then processing the resulting liquid, it’s possible to isolate the proteins present in leaves and make them more digestible to humans. Aside from protein, LPC also contains meaningful amounts of vitamins C, K, and E. As the necessary apparatus is relatively simple, it can be manufactured at a household level.

Cultured meat, also known as lab-grown meat, may be a viable solution in the future, but under current conditions it’s wildly unlikely that it would be affordable or produced in sufficient quantities under a nuclear winter scenario.

Lignocellulosic sugar can also be produced in factory or lab settings from lignocellulosic biomass, such as agricultural residues after corn and rice harvests. This would be one more way we could convert indigestible plant materials into food for humans.

Single-cell protein (SCP) can be produced industrially from CO₂ and hydrogen, among other inputs. The mechanisms for this would require significant adaptations of existing industry, but are well-understood and achievable. If policies advocating for this path were pitched and accepted, and the facilities were built starting at the beginning of the crisis, SCP could become widely available as a valuable protein source around one year after the onset of nuclear winter. One example of SCP is relatively well-known in the UK and commonly used as a meat substitute for plant-based diets: quorn.

Stockpiles

Unfortunately, contrary to what the zombie movies have told us, stockpiling foods in case of disaster isn’t going to be a big help in a nuclear winter scenario. For one, stockpiles are expensive to maintain, requiring a lot of cash up front and time to maintain. When so much of the world is food insecure as it is, it’s unrealistic to expect individuals, families, and communities to devote local resources to building stockpiles, especially indefinitely. Hoarding food in this way would also worsen pre-catastrophe food security, driving up prices and worsening the situation today rather than improving it in the future.

Secondly, nuclear and volcanic winters could last anywhere from one to more than ten years — we just don’t know. Even the longest-lasting, most shelf-stable foods only tend to last up to ten years.² Logistically, it’s impossible to produce stockpiles large enough to feed the global (and growing) human population over such a long period.

Conclusion

A nuclear winter would be unlike nearly any other threat humanity has faced. Unlike a local food shortage, importation or food aid can’t provide the only answer. In a global catastrophe, not only would other regions likely be unable to meaningfully assist an affected country, transportation systems may also have broken down, preventing the delivery of international trade goods.

However, providing for as many people as possible is in the best interest of any nation. If a country could provide food aid and continue exports, this might lower the chances of political and social upheaval, including refugee migrations to the southern hemisphere.

Next week, we’ll be looking at how we could incorporate some more of these frost-hardy foods into our diets in familiar ways. If you’re curious, tune in again:

For further reading on this subject, major sources for this article include:

• Baum et al. “Resilience to global food supply catastrophes.”

• Pham et al. “Nutrition in Abrupt Sunlight Reduction Scenarios.”

• Tzachor, Richards, & Holt, “Future foods for risk-resilient diets.”

• Wilson, Payne, & Boyd, “Food Supply During Nuclear Winter.”

1. And, actually, after — while nuclear winter is the most likely source of such a catastrophic event, it’s not unique. As we mentioned last week, volcanic winters and asteroid impacts could also potentially cause similar atmospheric effects.

2. Barring a few exceptions, like honey, which is shelf-stable indefinitely. Still, not exactly a well-balanced diet.