What is a Feasible Living Situation for Future Humans? Part 1

This is a guest post by George Mobus. It was previously published on his blog, Question Everything. George published this post, plus what I plan to publish as part 2 in a day or two, as a single post. Since it is quite long, I thought I would try dividing it into two shorter posts, posted a couple of days apart.

How Do We Establish Feasible Sustainable Living?

The peaking of oil extraction and refining appears to be upon humanity. The evidence is quite strong (if you want to follow this story I recommend you regularly read The Oil Drum for news and updates as well as technical reports). Because the cost of oil reflects to a large degree the imbalance between supply and demand, and has been pushing higher for the last several years, this has had a dampening effect on demand and a depressing effect on the economy. Thus, instead of an actual peak due to geophysical issues alone (the basis of the original peak oil theories) and subsequent decline, we are witnessing a bumpy plateau. Demand destruction leads to lower production in response and that means some oil is not being pumped out of the ground that would have been otherwise. But the overall trend is basically the same. Oil production will go down leading to upward pressure on the price we pay for each unit that is pumped. The feedback between the economy and oil production will mean that the process of decline will be stretched out a bit longer.

Nevertheless, oil is now on a depleting slope and however long it takes there is only one direction it can go. Just as problematic for civilization is that oil is the “king pin” energy source for modern industrial society. It takes oil to produce diesel fuel and gasoline, both needed to drive the equipment required for the extraction of other fossil fuels and all other natural resources. Oil is required for agriculture, transportation, and some heating. Natural gas, methane, comes closest to oil in terms of being able to replace oil derivatives for these purposes, but not without extensive retrofitting of the prime movers. That probably isn’t going to happen overnight simply because it will take a significant amount of oil-based energy and materials (lubricants and plastics) to produce the retrofits.

The crux of humanity’s predicament is this: as oil depletes we will find it increasingly necessary to reduce and abandon most of our economic activities as time goes on. Let me be clear about one thing in particular: Even though solar energy and wind, and even nuclear may be ramped up to diversify our energy portfolio, the fact is that none of these can begin to replace fossil fuels as primary energy sources to the degree needed to serve modern society. And that will even be true after we have cut back on all the wastage, discretionary consumption and made the most gains physically possible for efficiency. I realize that the political parties, the pundits, the general press, and just about everybody in the “green” movement (environmentalists and businesses) believe this is possible, but they are guilty of wishful thinking. They do not begin to understand the scale of the problem, nor do they grasp that our current fossil fuel basis for industrialization would be needed to subsidize the build-out of all the alternative infrastructure needed. In order to accomplish this in a short enough time frame to make a difference we would have to devote as much as 10-20% of our net energy flow toward that end, not to mention the redirection of other resources and labor. We would more or less have to suspend many of our current economic activities to mount a WWII+ effort in that direction. One has to honestly ask how realistic or feasible is that? Not that we might not try it, when it is obvious that TSHHTF (has hit). But I rather suspect we will probably bring too little, too late, to the effort and end up failing even as we use up precious resources for naught.

Unless some miracle breakthrough in fusion (or some obscure way to do fission without the technical hassles — like radioactive wastes!) comes very soon, the likelihood that humanity will have an energy rich future is practically nil. And here is the real trouble. The current population of humanity on this planet is possible only because of the abundant availability of oil and other fossil fuels. Nothing else can enable so much high powered work to be accomplished in order to produce the abundant food and conveniences of life that OECD countries have been enjoying and developing countries have benefited from secondarily. An end to the flow of oil is an end to modern society. And the decline of the flow of oil is the decline of modern society over the same time scale. It is even possible that social collapse will come sooner due to humans, who have been spoiled by the riches of oil, freaking out and doing something stupid. What are the chances of that, one might ask?

The simple truth of life is that it takes energy to do work and it takes high powered energy to do work quickly. And it takes a lot of it to do the amount of work we’ve grown used to. It is the work that we have done over the ages when energy flows were increasing that has given us this high-tech society in the OECD nations and that oozes into the developing countries. No energy, no work, no riches. Pretty simple really.

So what will we do? How will we adapt? What kind of society will we be able to have as the energy depletes and work slows down? Those are extraordinarily difficult questions to ponder. More difficult still to answer.

What I propose is to work backward from what an actually sustainable society might look like in some distant time after the adaptation has proceeded. What I will do is start with what we might call a ‘base case’ in which a tribe (village) subsists with non-mechanical technology in a reasonably comfortable life using ancient wisdom to achieve sustainability. Then we will start adding in other forms of energy subsidies from what many people believe, today, will be the salvation of humanity — wind and solar energies.

The Base Case: Low Tech

What might be the minimal requirements for human life that reflects some semblance of civil society and individual dignity? The reason for this question is that we need to start with some minimal acceptable condition as a base case. If we can establish a truly sustainable situation with this base case, we can then start to ask what else, especially in the way of adding back technologically-based conveniences, we can add to the mix. A year ago I wrote a post, “Our Energy Cocoon“, in which I described the exosomatic work that gets done in making our modern lives what they are in terms of a set of concentric rings of energy transformations. The inner ring involved the energies we use individually such as gasoline and home heating. As we progress outward the energies are used by others to provide the infrastructures of our lives, our work places, our grocery stores, etc. Further out still we find the hidden energy flows, the things that happen behind the scenes that we don’t tend to give much thought to but use considerable energies to keep our lives safe and untroubled (generally) by things like the Second Law of Thermodynamics! In the current approach I will start from the very core of the cocoon model and then see what can be added outward from that core.

What does an individual need to live? Certainly adequate food and water intake. A person needs to maintain a fairly narrow band of body temperature, so for any but the equatorial tropics, this means shelter and clothing. These constitute what Abraham Maslow calls the physiological needs (see: Maslow’s Hierarchy of Needs). But next up on the hierarchy comes ‘safety’, that is the security of knowing where sustenance is coming from, of having others around to provide backup and help provision where the individual might not be able to do for himself. So basic needs involve more than eating and drinking. Something like a tribe is needed to provide a social framework. Well that is exactly the situation that Homo sapiens evolved within so it isn’t surprising to learn that “No man is an Island, intire of it selfe…” (John Donne, Meditation XVII).

Maslow’s hierarchy continues upward with ‘love and belonging’ needs. It isn’t enough that we are surrounded by other competent humans that can help us out. We need to have feelings for them and know that they have feelings for us. Perhaps this is a more evolved version of safety, but it is a definite felt need. Next above love comes ‘esteem’. We need to feel good about ourselves. We need to think that we are worthy and that others see us as worthy. We need to see ourselves as contributing usefully to our social group. We need to be needed. And at the apex of the hierarchy we find the need to ‘self-actualize’, to realize a sense of freedom to create and explore, a spiritual wholeness that is the basis for happiness.

So if we are to construct a base case in which human needs are fulfilled, where life is worth living, we must start with these as the minimum requirements.

Note that nowhere in this description of human needs do we see something like the need for Monday Night Football, or a Mercedes. We don’t find caviar in the list. Nor, importantly, do we run into iPodsTM or iPadsTM. You won’t even find the Internet or the World Wide Web in this hierarchy. In other words, we humans can actually achieve self-actualization without these things. There is no question that all of these kinds of things have made life for many more enjoyable, at times. But then, the other side of the coin is that many of those same people found themselves working harder and longer hours at less than satisfying jobs so as to be able to afford them. In the long run, probably not a great trade-off.

Thus we arrive at a basis for starting our analysis. Tribes, in prehistoric times, may have generally consisted of between 100 and 150 individuals in extended families (perhaps several somewhat related families). Later villages may have extended this number to around 300 to 400 but rarely more than that. It becomes impossible for an individual to have close personal relations (good or bad) with a large number of other individuals. It wasn’t until the advent of agriculture that we start seeing larger villages, say over 1,000 in population. So let us assume that a workable base case would be to support 500 individuals, each of whom has the opportunity to reach self-actualization for an extended period of life. Like good physicists we will ignore extraneous factors for the moment. We will hold climate reasonably constant for this analysis.

What will it take to sustain 500 individuals in a manner that will allow them to achieve self-actualization, to fulfill their basic human needs?


Life is based on the influx of solar energy over an extended area of land. The food chain (of which we will assume humans to be the top consumer) is based on photosynthesis at the base. Assuming a moderate climate, adequate water, soils rich in nutrients, and a reasonable growing season, with photosynthesis generally running around not much more than 3-6% efficient the total amount of biomass produced per unit of time, the net primary productivity (NPP), will be the constraining factor in determining land requirements at local levels of solar insolation. In order to provide a diversity of NPP forms, food, wood, fiber, etc. the territory will need to be large and varied in composition.


As indicated above, the principal form of energy influx will be real-time solar energy. By real-time I mean the daily insolation that contributes to primary productivity. Humans have to eat daily to keep living and acting in the world, but plants grow slowly and not all biomass is edible. Therefore, large territorial regions are needed to support even small populations of humans without degrading the environment. Trees, a source of building materials as well as extrasomatic fuel are required in the territory to supplement heating needs. The basic problem is to trace the conversion of sunlight into usable food and other biomass resources for a specific locale to work backward to see how much land is needed to collect that much solar energy for five hundred, or so, people.

But it isn’t just the cultivated land area that we have to consider. Humans need to have water in a regularly flowing, cleansed form. This is accomplished in nature through the hydrological cycle powered by the sun producing rain in highland areas that are covered with trees and understory plants. An ideal human settlement will be at the base of an elevated region acting as a watershed and providing cleansed water flow. Moreover, the flow of a stream or river from elevation is another source of energy that might be used directly for human purposes. More later on this.


The cultivatable areas require soils of a high quality capable of sustained permaculture practices. To maintain soil in its optimal state requires either the import of organic and nutrient materials (e.g. nitrogen in a form that can be taken up by plants) or recycling of these systemically. Soil management is one of the first forms of technology and knowledge that needs to be understood and used. The most conservative approach is to assume the need for recylcling of nutrients locally. This is not easy to accomplish in practice so careful thought is required to ensure its achievement.

Climate and Rainfall

As noted, the territory must be situated in a region with stable climate and adequate rainfall in the watershed. The former requirement is being complicated by the fact of climate change due to global warming. I have some thoughts on how to enjoy some stability but it will need further research to realize. The latter requirement is, of course, complicated by the former situation. To some degree these unknown variables might be mitigated by adjustment of the territory size, assuming the other considerations (requirements) have been met.

Building Materials and Fibers

To live comfortably means adequate shelter and protection from the elements. The local natural (endemic) species of trees and grasses will need to supply these. They will need to be endemic because support for non-native species often requires extensive artificial inputs because those species are not well adapted to the local conditions.

Building materials will also include local clays and rocks. This is another reason for locating a territory at the base of a mountainous region.

Animal Biodiversity

As a complement to and backup for permaculture-based food production, the territory should have a relatively high biodiversity in animal life.

How these all are to be organized will be covered in the next segment, planned for Friday, December 24.

About Gail Tverberg

My name is Gail Tverberg. I am an actuary interested in finite world issues - oil depletion, natural gas depletion, water shortages, and climate change. Oil limits look very different from what most expect, with high prices leading to recession, and low prices leading to financial problems for oil producers and for oil exporting countries. We are really dealing with a physics problem that affects many parts of the economy at once, including wages and the financial system. I try to look at the overall problem.
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17 Responses to What is a Feasible Living Situation for Future Humans? Part 1

  1. Kim Hidinger says:

    Thank you for another great article. Where else could anyone get that kind of information in such a perfect way of writing? I have a presentation next week, and I am on the look for such information.

  2. Greycat says:

    I think what George is writing about and what I’m worried about are two different things. George, it seems to me, is writing about an ideal situation he hopes we can manage. I am assuming that the situation will be more like the past where warfare, though on a smaller scale than modern warfare, was fairly common.

    Of course, even in the past different situations were different. In 700 AD Norsemen raided England and caused great suffering. In 1200 AD this was no longer a problem.

    Also, while I expect that with reduced resources only a lucky few would be able to truly flourish, this does not mean, for instance, that all women will be illiterate and have to spend all day doing domestic chores and die young from the necessity of having many pregnancies to ensure that enough children survive to continue the family. St. Hildegard, Christine de Pisan, Heloise, and others had leisure to think and write during the middle ages. I just think many men and women will not be able to do those things in a future with reduced resourcesw.

  3. Pingback: What is a Feasible Living Situation for Future Humans? « UKIAH BLOG

  4. Paul says:

    It seems to me that a population of 300 to 500 for a community/tribe is too small, but I must admit I have not found and read whatever reasoning lead to pick that number. My thinking is based on limited knowledge of city states of ancient Greece. Those people lived in cities which seemed to have a few thousand ‘citizens’. A citizen was a head of household. So the actual population was perhaps 4x or 5x that number. The ancient
    Greeks thought about and wrote about the ideal size of a city. I incline toward the belief
    that their city size was not arrived at by right reason, but by trial and error. And only afterwords was the right reason created to support the reality. However it happened, I suggest it might be worthwhile to address the issue of why you preferred size differs from the one arrived at by the ancient Greeks.

  5. Pingback: What is a Sustainable Living Situation for Future Humans – Part 2 | Our Finite World

  6. Joe Clarkson says:

    While it is true that most modern technologies cannot be supported by a population of 500 people, some products of the fossil era may last for a generation or so before they fail. PV modules are one of them. Recycled lead acid batteries (in wooden boxes lined with poly film) may well be another. Put those together with LED lighting fixtures and it may be possible to keep electric lights going for 40 or 50 years. All of these things will eventually fail, but I see no reason to go to beeswax candles or oil lamps immediately if even my thirty-ish offspring could have good lighting for the rest of their lives.

    One of the renewable energy projects I participated in back in the late ’90s was a solar PV lighting project for remote rice farmers in Fiji. At first it was very surprising that these very poor folk would be willing to pay the equivalent of $2.00 per kWh for electricity. But, when one sees what fabulous illumination a few kilowatt hours a month will provide (20-40 W of CFL lights for 4-6 hours an evening), especially compared with kerosene lamps or candles, it is not so surprising.

    Light is the most valuable thing that electricity can produce. It may well be that, in the not too distant future, the most visible evidence of those who are really doing well will be a couple of electric lights shining though their windows.

    • Jb says:

      Joe, I figured out during previous electric power outages that I could run my LED Christmas lights off my battery/power surge protector batteries for my computer. We are the only house on the block with lights at night during such events. It boosts our spirits much the same way as does a nice fire in the hearth. My goal is to purchase a small portable PV system so that we can continue this practice after the grid goes down….

  7. Bicycle Dave says:

    Thanks George, I look forward to the next part.

    This all seems so surreal! Alice in Wonderland seems more real and rational than contemporary life as witnessed daily in the workplace, on the expressway, on cable TV, in politics, in the local church, in our wars, our economy and most everywhere one turns.

    I often think about Jared Diamond’s “Collapse” and how the cultures he studied seemed oblivious to their peril until it was too late. Western countries now live in a “Car” culture – the motor vehicle dominates everything. It would seem that any rational person could foresee the demise of this culture somewhere in the next 20 years or so. Any yet, for the most part, serious criticism of this culture is pretty much immediately dismissed as absurd. For example, our Wisconsin Governor elect, as promised in his campaign, returned $800 million dollars to the Federal Government. The money was intended for trains. The new Governor, supported by voters, vowed that he would only spend tax dollars to support private motor vehicle transportation – he would rather send the money back if it could not be used to support the car culture.

    Although there is a small minority of people who understand the issues as George is outlining, my experience here in Wisconsin leads me to believe that the majority opinion is that “you will take my car from my cold dead fingers”.

  8. This is a fine discussion. I would like to see it expand into the subject of health care, a high tech, fairly centralized, very expensive, insurance-dependent part of our economy. This cannot be managed well on a 300-500 person unit (village) level. And it seems to me it should appear early in the Maslow hierarchy of needs (under safety.) Thank you.

  9. Jb says:

    Gail and George,

    Thanks for a terrific post; I’m looking forward to the next one. A bio-capacity study was done for my area. The soil, water and wildlife here will only support a fraction (25%) of the current population.

    • I always wonder what the bio-capacity would be if we lost diesel operated tractors, fertilizers shipped from a distance, pesticides, herbicides, fruit sprays, electric fences, irrigation pumped by electricity or diesel, and refrigeration of produce after it is produced (so we can ship it or use it later). I have a suspicion that the number who can be supported could easily decrease even more.

      • Jb says:

        Gail, I think you are correct. Without that extra support, farming will become much more labor intensive and with lower yields. This will create seasonal famines and other health related issues like those suffered by our ancestors.

  10. It seems to me that there are two different types of wind. There is mechanical wind, that has been used for hundreds of years, to pump water, and even to run factories. See this post by Kris DeDecker. It seems to me that mechanical wind is certainly available, but I doubt that wind turbines of the type used to power electric generation can be maintained for long, because they need to have parts that are made of very specific materials, and parts need to be machined to very close tolerances.

    In fact, many of the technologies described in Low Tech Magazine will still be available.

  11. Jerry McManus says:

    The crux of humanity’s predicament is this: as oil depletes we will find it increasingly necessary to reduce and abandon most of our economic activities as time goes on.

    Not quite. The crux of humanity’s predicament is ecological overshoot on a global scale. This can be very roughly defined as “too many people consuming too much stuff and producing too much waste”.

    Yes, of course, it can be argued that highly concentrated and easily transported fossil energy is what enabled the overshoot to begin with, but in the context of our current predicament any systems thinker can tell you it is only one of several rapidly depleting resources we are dependent on, and not necessarily the most critical one. All the oil in the world will not help you if you cannot grow food.

    As Liebig said, a system is only as resilient as its most scarce resource. I would amend that to include “or it’s most limited sink”. After all, the yeast in a vat of wine do not die off due to a lack of sugar, they drown in their own excreted alcohol waste. Our atmosphere and our oceans were once considered limitess sinks, now we have only just begun to feel the feedbacks from those tragic mistakes. Feedbacks with delays measured in decades, if not centuries, and that will continue to be felt by countless future generations.

    Finally, I suspect there will be economic activity as long as there are people around to trade goods and services, long after the last “economically” recoverable oil has been burned. Certainly not activity on the scale people in the wealthiest countries have been accustomed to, but what about the other four fifths of the worlds population? Will they not shed a tear for the demise of all those fat rich people and their poisonous cars?

    Probably not.

    • George Mobus says:


      We are probably mostly on the same page. Your statement that “…any systems thinker can tell you it is only one of several rapidly depleting resources we are dependent on, and not necessarily the most critical one.” is interesting. If you were to explore question everything (my blog) you might discover something interesting about me!

      I hold that energy IS the most important limiting resource because it is non-recyclable, unlike most materials, and there is no alternative substitute for doing work. And, with a sufficient amount of energy available it is feasible to drive recycling given a sufficiently small population within a steady-state economic framework. It is lack of energy that makes other resources become too expensive to obtain. Similarly it is feasible, given enough available energy at the right power level, to reprocess wastes (part of recycling in most cases).

      As for overshoot, you might be interested to learn that I did a review of William Catton’s latest book which was posted on TOD. Fossil fuels, in my mind and in consonance with the available evidence is the factor that allowed human populations to go so far into overshoot. In fact the history of humanity can be rewritten to see it as a progression of finding and exploiting increasingly powerful forms of extrasomatic energies, all of which always allowed us to go beyond the limiting bounds of mere somatic energies (food). Ergo, declining energy sources mean declining population, one way or another.

      As I said, we are probably not that different in overall views. This one article simply puts focus on one dimension of a complex situation.

      • marty schoffstall says:

        I like your post, but i’ve come to the conclusion that there are other non recyclable classes that are less driven by enthalpy – or at least non recyclable in the lifetime of an individual civilization.

        I’d like to talk about Land. When I was a kid in the 60s I asked my parents why they were bulldozing the dirt off the farm near us, and their response was “to build houses”. It seemed odd
        to me and we eventually
        bought one of those houses. what was 3 ft of top soil became 1/2 inch of “topsoil” over clay, my father struggled trying to turn a 20×20 plot into a garden on our 1/2 acre lot.

        That “model” that was 2 miles from the city in the 60’s has now extended 20 miles from the city when it finally crashed and burned in 2007. a rough quadrant of 11 square miles became 315 square miles of sprawl in 40 something years. that land is gone for the purposes of our civilization. The ironical part is that it was rich agricultural land, well watered, with springs everywhere.

        Once upon a time in America per my readings is that 50% of land was grazing for the local motive part of our economy and agriculture (horses, oxen, etc), and the other half was food for humans. While I’d like to believe that bicycles and EV’s and bio-diesel trucks might be in operation, there are amazing changes to the roadways already for lack of maintenance. In southern Africa concrete roads 10 years after no maintenance are pretty scarey, and 10 years is 1/6th of the life of my 14 year old.

        I am clueless how we might feed ourselves on organics and permaculture in these enivornments.

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