Food Energy The Fragile Link Between Resources and Population

Food Energy The Fragile Link Between Resources and Population

Food-Energy: the Fragile Link Between Resources & Population

excerpted with permission from The End of Fossil Energy and Per Capita Oil by John G. Howe of Waterford, ME

Every successful species harbors a genetic drive to reproduce more numbers than can be supported by a stable, sustainable environment. The limitations are food, non-energetic resources necessary as building blocks for life, competing spe- cies (also hungry for food), a hospitable ambience, and adequate physical space. Those who best adapt evolve as conditions crowd out or supercede those that don’t. This is simple Darwinism and most often infers a short, harsh individual life of competition and survival. Changes in the environment by natural causes and/or environmental destruction add additional challenges to the status quo, and favor those species which are fortunate enough to adapt, or smart enough to plan ahead.


Humans acquire their energy from food which at one time came directly (or indirectly farther down the food chain from other plant eaters) from plant photosynthesis of incoming solar energy. As quickly as new offspring begin to grow on their own, increased demands are placed on the food supply although at first it may be as food-energy still supplied by a supportive parent(s). As long as food is available the population will increase to the limits of the species’ range, individual or collective skill (including tools), and individual energy available to procure the food and/or avoid being food for others. It should be obvious that population is therefore limited first and primarily by the ability to access and store food…

To continue our analysis, we will focus on the food-energy balance required for human survival without relying on a temporary surge of non-renewable energy capital, e.g., fossil fuels, or imported food from another location or time (inferring a surplus somewhere else). For hundreds of thousands of years our predecessors lived as hunter-gatherers in a precarious ratio which had to be larger than one, between Food-Energy Returned On (Personal) Energy Invested (FEROPEI).


Then about ten thousand years ago, humans learned to utilize favorable, unique, local growing conditions and crops. The age of agriculture began. A slight improvement of human FEROPEI, combined with reduced energy requirements and risk related to excessive travel, provided a tiny energy surplus to support the beginning of recorded history. The extra energy made possible early civilizations and the construction of ancient monuments many of which have survived to this day. To build anything of substance, the energy has to come from the excess over and above the primary requisite-energy required for personal food and survival. Instead of a hunter-gatherer barely able to procure food for himself and enough progeny to perpetuate the species, a hard-working farmer with favorable ecological conditions could now feed additional dependents plus non-farmers. Energy-intensive travel was still limited by human personal mobility, draft animals, and wind power for sailing.

Because of agriculture, the average FEROPEI improved, possibly up to 6:1. This provided the steady-state support for long-term societies like the Chinese, but could not support continued growth of extensive, non-agrarian expansion like the Roman Empire. Many societies flourished, then collapsed because of the inevitable conflict between growing populations and the limitations and degradation of local food-carrying capacity.


Following the collapse of the Roman Empire, slow adaptation to wind, water, and draft-animals gradually improved local agricultural output by reducing the direct dependency of food output from human-energy alone. The food-energy return on human labor input (FEROPEI) slowly increased up to the 10:1 or 12:1 range. Still, population was held in check by disease, poor health care, unpredictable diet, infant mortality, and short life spans. But, the new energy surplus made possible multiple layers of non-farm population, societal administration, and cities. Marketing, money, and laws evolved on the backs of peasant (or slave) farmers. There was enough extra energy and manpower to support armies and wars required to wage territorial, resource, and cultural disputes.

A very erratic and slow increase in world population continued up to just several hundred years ago. Additional food sources and room for growth came primarily from exploration and settlement of new lands. Malthus’s prediction of population limits was temporarily proven wrong because the exploitable world seemed limitless. Then, suddenly, inventions of new ways to exploit the convenient vast stores of finite fossil energy, far beyond renewable wind and water, made possible and began the industrial age. As would be expected, the unprecedented utilization of non-human energy escalated the food-energy available for human consumption and population growth.


The utilization of vast stores of pre-stored fossil energy, beginning with coal two-hundred years ago, and followed by oil and natural gas, suddenly jumped the ratio of food energy returned on personal energy invested (FEROPEI) to as high as 300:1. One farmer could now feed three-hundred people instead of six by himself or twelve with the help of animal power. Concurrently, in the same short period, as would be expected, world population soared from one-billion to seven-billion. This was due to many factors directly related to the sudden energy bonanza. Access to formerly remote lands, genetic crop improvements, inorganic nitrogen fertilizer, pesticides, energy-intensive farm equipment, irrigation, refrigeration, packaging, and long-distance mobility all contributed to the modern lifestyle now enjoyed by the industrialized world. Concurrently, giant strides in medicine and health care vastly increased life span and population. But still, all must eat with the same basic individual requirement(s)…

In the past several decades the “green revolution” maximized food production and made possible the seven-billion humans now needing food. However, this final push is unsustainable and is causing new problems; for instance, genetically modified (GM) foods may be linked to new health risks.

Resilience, an advantage of crop diversification, is absent. New pesticides, monoculture, and herbicides also lead to super-bugs and environmental contamination. The societal improvements promised by capitalism and industrialized agriculture are, in effect, just more examples of temporarily polarizing wealth between the masses and the few who control the system. Finally, and obviously, the mechanization of modern agriculture cannot continue without oil.


Now, after a one lifetime span of almost free energy and resultant copious food, the entire world faces the imminent decline (and eventual demise) of finite, fossil-fuel capital and therefore must inevitably face a return to the food-production default range with a FEROPEI as low as 6:1 or, at most, 12:1. This assumes individual farmers can retain a semblance of traditional agriculture, knowledge, hard work, and renewable energy, while drastically reducing non-food energy expenditures for travel and keeping warm. This is the “end point” we must return to in the next 60 to 80 years while, in the same one-lifetime span, reducing the numbers to be fed from the present seven billion back to, at most, one or two billion who must also be located very close to their food source. Without fossil fuels, food can no longer be produced in one area and shipped thousands of miles to market. Nutrients must also be returned to their source. To suggest that the world will be able to feed the UN projected population of nine billion by 2050 is totally incomprehensible in the face of declining oil…


Homo Sapiens will survive. Our ancient ancestors lived off the land and survived ice ages (without metal or plastics). But, in order to avoid total collapse first, we must clearly recognize our predicament in quantitative terms and define exactly what to do. We must get started immediately to allow time for a commensurate population reduction through natural attrition instead of famine, war, and disease. We will not make it without three basic prerequisites necessary in the time and direction available:

  1. Explicit knowledge and broad publicity of what to do, and why we (including you) must get started immediately, especially networking this story.
  2. Negative population growth at a level of not more than one child per female (or male).
  3. A systematic reduction of American per capita energy consumption from 22 b/b/y to 3 b/b/y (billion barrels per year); including rationing, in the next thirty years.

All must be done.

We should avoid wasting and/or fighting over the remaining oil. Never before in recorded history has there been so singular a resource as oil for food, or the urgency for a controlled descent from the ephemeral peak of energy usage we enjoy today. No other species has achieved the feat of anticipating and systematically executing an energy and directly-dependant population reduction.

In my office piled high with pertinent web print-outs I have one, in particular, a comprehensive classic (, Oct 20, 2008). It is a paper by Peter Salonius, a Canadian soil microbiologist. The title, Agriculture: Unsustainable Resource Depletion Began 10,000 Years Ago, and six parts including Part 4, Intensive crop cultures are unsustainable, cover the entire theme that “human population numbers will have to be brought into balance with the sustainable productivity levels of the local ecosystems upon which they rely for their sustenance”.

In Part 6 is a wonderful concluding paragraph:

Balancing of human numbers to the productivity of their supporting local ecosystems may be accomplished by planned attrition, much lower birth rates and the economic dislocations and hardships that a retreat from classical economic growth will incur, or the balancing of human numbers may be accomplished by a catastrophic collapse imposed by natural resource scarcity. The species with the large brain must make the choice between economic hardship and catastrophic collapse.

Now in my eighties, I speak as a retired engineer but with a lifetime of farming experience. I would be happy to send a copy of my book to anyone who provides a mailing address: 298 McIntire Road, Waterford, ME 04088. A ten or fifteen dollar donation would help but is not necessary. See