Book Review: Food, Energy and Society (Pimental and Pimental 1996)

My new “text only” morning routine is paying dividends. Rather than staring at padded out YouTube videos I clear my emails and messages over breakfast, scan the headlines, then dive into a book if I have time and energy left before the morning farm work kicks off.

Consequently, I got through this interesting book which has been sitting on my to-be-read pile for many months. Previously I aimed to review one book a month. With my currently complicated life this might increase to every third substack post. Hopefully that will be of interest to the audience here. To make it interesting, here is a survey of a few options for the next book to review. Rather than a democratic vote I will go with the person who makes the most enthusiastic comment for their preferred choice. I hope to get through all of these over the next year or so.

A. Tombstone- The Great Chinese Famine 1958-1962

B. Darwin’s Cathedral- Evolution, Religion and the Nature of Society

C. A New Science of Life (Sheldrake). The Hypothesis of Morphic Resonance

D. Small is Beautiful- Economics as if People Mattered

E. Plant Breeding for the Home Gardener (Tychonievich)

F. The Blithedale Romance (Hawthorne)- a lightly fictionalised account of a real 19^th century intentional community that imploded due to romantic jealousy.

G. Ultrasociety (Turchin)- How 10,000 years of war made humans the greatest cooperators on Earth.

H. The Art of Fermentation (Katz)

I. Harvesting the Biosphere (Vaclav Smil)

J. Deceit and Self-Deception (Trivers)

K. Ultrasocial (Gowdy). The Evolution of Human Nature and the Quest for a Sustainable Future.

L. End Times (Turchin). Elites, Counter-Elites, and the Path of Political Disintegration.

M. Daedelus (JBS Haldane). A 1924 vision of biotech and transhumanism.

N. Endangered Maize (Curry). Industrial Agriculture and the Crisis of Extinction.

O. Darwin’s Conjecture (Hodgson). The Search for General Principles of Social and Economic Evolution.

P. Los Viejos (Halsell). Secrets of a Long Life from the Sacred Valley.

Q. The Training of the Human Plant (Burbank).

R. Hybrid (Kingsbury). The History and Science of Plant Breeding.

S. A History of Civilizations (Braudei).

T. Evolution “On Purpose” (Corning). A set of essays on evolved purposiveness.

U. Darwin’s Unfinished Symphony (Laland). How Culture Made the Human Mind.

Moving onto this review, this book was an interesting time capsule since the version I read was from 1996. This was before the popular online peak oil panic that led up to the 2007-08 global financial crisis, complete with textbook record oil price spike (and quickly followed by a collapse in oil price along with interest in peak oil). This book featured repeated predictions that US oil production would end in 10-20 years (somewhere between 2006 and 2016), which was approximately correct if you leave out the dramatic (and likely short lived) impact of fracking. The book also predicts 30-50 years for world oil production to end, which is lined up within a decade of 2036. Time will tell if a global fracking boom delays that event.

The book also discusses human population growth problems from the perspective of 1996, projecting ever increasing numbers all the way up to 2100. In more recent years the collapse in birth rates has extended to the developing world much faster than predicted, and this trend is likely to continue to accelerate in coming decades. The hopes for biofuels, biomass electricity and solar PV are also interesting to look back at from three decades on. I wonder what solid projections from today will hold up in 2055?

A lot of people don’t realise that per capita fossil fuel use has been declining in the west since the 1970s, though Europe took the lead in this regard in terms of per capita surplus resources. A really lovely comparison was drawn between today and ancient Egypt. During its golden era, 95% of the Egyptian population were farmers, each producing a mere 15 kg of surplus grain a year to support the remaining specialists. As population grew further this surplus shrank. Initially military excursions added spoils and slaves to the economy, but soon there was too little surplus to support an army so the society stagnated, monument building degraded then stopped, and eventually Egypt was conquered.

This book brings together quantitative estimates of how energy and food systems work, so even though some aspects are a little dated it is still a fascinating read. One eye opening statistic- the landscape of the USA captures 13.5 peta-kCal of solar energy every year through photosynthesis. Of this around half (6.9 peta-kCal) are harvested by humans through agriculture. By comparison, the US economy burns 20 peta-kCal of fossil fuel energy per year.

The middle chapters contain a trove of data on the EROEI (energy return on energy invested) of a wide variety of human lifestyles. !Kung foragers often camp near a water source, then harvest staple foods like nuts at ever longer distances from home base. Eventually they start needing overnight trips to bring food home, and the EROEI drops dramatically, forcing them to move to a new location. Firewood is also depleted in parallel.

Slash and burn agriculture in Papua gave an EROEI of 12, but required 90% of the growing space to be fallow at any time. Pigs ate about half of the harvest, but served as a buffer during crop failures. The highest recorded EROEI was for hand grown African cassava, giving an impressive 23 (though these regions suffer chronic protein insufficiency as a result).

In a similar pattern, cattle herders in semi-arid Africa gained an EROEI of 0.5 from their enormous herds (4 cows per person, grazing 10 hectares per animal). Their main energy source was crops of sorghum grown during rainy seasons, but these failed often enough due to drought that the cattle were an essential buffer.

Interestingly, the EROEI of industrial fishing was consistently below 1. The oceans were described as uniquely unproductive spaces, partly due to low photosynthetic efficiency, and also due to usable harvests (such as fish) requiring many trophic levels of energy exchange (each with a low percentage of energy transferred). Fishing supplied protein for about 1 billion people in 1996, but wild stocks were declining and the EROEI of aquaculture is even lower than wild caught fish.

A general pattern emerged through the study of grain cultivation. Growing crops by hand gave the highest EROEI, with declining energetic profit as methods became more intensive.

A really interesting section outlined how a human, working with simple hand tools, needs about 200 000 kCal to hoe a hectare of crop land, taking about 40 days of work. A team of draught animals can do this work much faster, but their total energy consumption increases dramatically (though often these animals are powered by low quality biomass which humans could not eat directly). This same pattern is further extended with fossil fuel powered machinery, which can do the work faster than animals, but demands even higher total energy inputs (but again, in a form of oil which is useless to both man and beast).

Humans are extraordinarily energy efficient creatures. The question is, how happy are we spending most of our waking hours hoeing, weeding, reaping, threshing, winnowing and grinding grain? And if we aren’t happy with this life, how do we collectively escape the trap of productivity?

The issue of depleting biomass (for use as firewood primarily, but also construction) was also explored. About half the world’s former forests have been lost, and cooking food consumes about twice as much energy as the food itself contains. They also explained that it takes on average 640 kCal to transport every kilogram of food from the farm to the shops, yet around the same amount of energy on average is used transporting it from the shops to the home.

Reading this book stirred up a range of thoughts. The first one is the limits of fungibility. That lovely term refers to the interconvertibility of an asset (for example how easy it is to convert one form of currency into another). During the late 20^th century oil was considered to be a fungible asset, since surplus production from a wide variety of sources could smoothly substitute each other. That period of operational flexibility is going away as production and flows become more constrained.

It brings up a deeper issue- our understanding of energy relies on reductionist science that discovered the laws of conservation of energy, plus the unavoidable energy losses when converting from one form to another. In practice, energy is not fungible, and the past simplistic view of all energy being interchangeable or even comparable is becoming less relevant for the real world with every passing year. The examples comparing the EROEI of grain cultivation powered by human energy, livestock or machines is salient. High quality human food, low quality pasture or toxic coal/oil are only indirectly related to each other in the real world. Boiling each method of production down to the same raw units of joules is interesting on some levels, but ultimately we are comparing systems of agriculture which are fundamentally different.

Every day, I am confronted with the reality that staple calorie crops are just one essential ingredient in human flourishing. The balance between all of the elements necessary for society is just as important. The massively improved yields of rice farming in ancient China triggered a population explosion, which led to chronic firewood shortages to cook that abundance of calories (and changed the landscapes to make catastrophic flooding and erosion more likely). The astonishing yield of cassava (EROEI of 23) when introduced into tropical Africa just led to societies with chronic protein insufficiency, leading to stunted children with mental retardation.

This leads me to the real fundamental question facing society. What is the optimum percentage of time devoted to securing food and the other necessities of survival? Let me throw together a made-up thought experiment. We have three different kinds of societies to compare.

A. 100 hunter gatherers who spend 70% of their time foraging. This gives 30 full time equivalent human lives (30% of 100 people) that are free to do non-essential tasks.

B. 1000 farmers who spend 80% of their life farming. That leaves 200 equivalent free lives.

C. 10 000 industrial suburbanites who spend 90% of their life “working”, leaving 100 equivalent free lives.

This thought experiment mirrors the shift from hand to animal to machine powered grain production. The total yield increases. The speed of operations quickens. But the efficiency of the operation decreases with every “improvement” if the point of securing food is to do something else.

If there is some kind of “optimum” society, I suspect humanity sailed well past that point long ago. We are like a mosquito that pushed their proboscis into a high-pressure artery and are swelling like a beachball, fit to burst. I keep thinking of cacti from ultra-arid environments. If you grow them in a pot and overwater them, the plant swells until it splits open. In the wild the plant never encounters such abundance, so it has no mechanisms for moderation. A human body swollen with junk food calories is not that different, given they evolved in a world where starch and sugar were rare.

You might want to take an alternate view on industrial society and argue that we have far more free time for leisure than our farmer ancestors. This may be the case, but that then brings up the question of what free time for humans is even for, and is there an optimum amount of it? Imagine you could swallow a single pill which would supply you with all the nutrients you need for the rest of your life. You now have an extra 40 hours a week of free time, as do 8 billion other people. What would we do with that time? Are we already facing a stagnating surplus of human potential? Would we all just do crosswords and play Candy Crush to pass the extra time?

This line of questioning brings us to deeper questions. What is the purpose of humanity? What is the purpose of life on Earth? What is the purpose of the universe itself, if it has any other than converting high quality energy into waste heat as fast as possible. If that is all there is to existence, then industrial civilisation and its overflowing landfills are the crowning glory of creation.

What if the universe is just one great outrageous party? Perhaps we grumble at the effort of picking up our spoons and forks to shovel the riches into our mouths. Perhaps we feel sorrow at the inevitable mess we will leave behind by merely existing. But rather than apologising for our nature, for the immutable laws of flow and decay behind everything, maybe we should say thank you for being invited in the first place. With that necessary politeness aside, the only remaining way to pass our time is to discover how the feast that we call the universe was created in the first place.

My next guest on the Zero Input Agriculture podcast, Julian Gough, has an astonishing theory on that front. I hope you get a chance to check it out.