Imagine you’re on a small island (metaphorically speaking, a little ball in the universe), and you theoretically have only one source of concentrated material—a small hill, so to speak. You also have a piece of land just sufficient for growing food, and nothing else matters.
Let’s say that hill is limestone. The rest of the island is a dust desert: land in thermodynamic equilibrium. The land and dust are unusable unless you invest an enormous amount of energy to upgrade it or make it fertile—and you don’t have that energy, except food for your own labor energy.
You can use that limestone, with your own labor, to build a house, for example. But once the hill is gone, it’s gone. The supply isn’t replenished—nothing grows back (on short term,see below). So there is a limit to what you can do with material on that island. The island has a natural cap on energy and material use. On transformation potential, so to say. From solar energy via food to labor to mass to house. Done. And that limestone itself went through the same path to form it the first place! (form solar energy to food to species to mass. )
Meanwhile, that piece of land does produce a new supply of food every year. That regenerates. But in this example, none of that surplus is available for anything other than food. There’s no extra land. That’s the assumption. Which means the energy supply is replenished annually—in the form of human labor—but the material supply is not. (Except maybe some leftover material, like straw, that could be used as insulation.)
Of course, on other islands with more land that isn’t in thermodynamic equilibrium, more can grow and more resources remain. Trees and forests regrow annually, providing a limited but renewable supply. But as far as non-organic raw materials go—they remain finite. Once they’re gone, they’re gone. It requires ever more energy and labor to get them available in usable concentrations , and the less concentrated the more energy required . Its not for a reason that only since the fossil revolution metals could be abundantly used.
Going one step further: “Gone” doesn’t mean gone forever. Concentrated reserves are depleted, but they do get replenished—over millions of years—through geological processes like tectonics and volcanism. Everything is regrowable—eventually. But in the short term, that’s no help. See also my recent book The Space Time Economy, and earlier blog posts.
You can calculate how much is geologically formed per year and treat that as renewable—but it’s absurdly little, as I’ve calculated. [1]
On an island the size of Earth, it takes time before we run out of current supplies. But what’s happening now is a huge decline in reserves—especially the rich sources, which we mine first. Take copper: there were once mines with 20% copper ore. Now it’s about 0.5%. That means vastly more energy is needed to extract the same amount of copper. (If it goes from 0.5 to 0.25%, that requires 4 times as much energy.)
That’s one of the main reasons for global unrest right now: everyone is chasing increasingly scarce resource concentrations.
And without fossil fuels (if it comes to that), energy must also come from renewable sources within short timeframes—directly (burning biomass, wood) or indirectly (via food and labor), as was the case before the industrial revolution. That determines an annually replenishing supply availability.
So it’s better to use organic, biobased resources from the start. That significantly reduces the strain on and depletion of the system, and also avoids nasty side effects like biodiversity loss, health-threatening pollution, and climate change, to name a few.
Using non-organic materials isn’t entirely off the table, but it requires disproportionately large amounts of organically regrown material (as energy, grown on land) to make them usable. That reduces the land’s capacity to produce food and biobased resources. For example: you can build a house with about 15 m³ of wood. If you burn that wood as energy to produce cement and concrete, you’ll only have enough material left to build half that house. That’s not smart. If you’re the only person on Earth, fine—but with 8 billion people, that’s a problem. Someone ends up hungry. (Due to land shortage—without using fossil fuels, of course.)
There are other indirect solar-energy routes—like building a windmill from remnants and carefully managed renewable resources. A wooden windmill, for example. With only the most essential parts made of metal (produced with organic-sourced energy). Or a wooden water wheel. These are optimization decisions around land use for needed resources versus food and housing needs. (Also in the book, and soon more examples described here.)
The point is: without fossil fuels, the only viable basis is biobased, i.e., organic. That gives us an annual budget, and how we manage that determines what we can do. It’s also the starting point for deciding whether or not to use non-organic materials—only from residual availability, after basic needs are met. There’s no alternative: energy is needed, and it can only come from the one inexhaustible source: solar energy (and its derivatives, water and wind), which again requires materials—and thus land and energy.
Sure, there are exotic options—some areas have geysers, and geothermal energy can be used cleverly (without too many non-organic materials—see Low-tech Magazine). But in general, it’s useful to look back 200 years: where did people get their energy and materials? Local windmills, a waterwheel in a river, or flowing water in the mountains. And labor, lots of labor.
Even labor from horses and oxen—Paris had around 80,000 horses in 1880, though energetically, that wasn’t very efficient. Food converted via a horse yields less net energy than food via a human.* Still, it made sense—horses did heavy work. But it came at the cost of huge areas of land for feed. (And the smell and dung in the streets.) The people back then had chosen to use part of their land: as an energy source via horses. (Not the best option as we can also learn form one of the most sophisticated sustainable cultures; Edo-era Japan, 17th–19th century—lived optimally off annual yields, and didn’t use animals as tools.)
Forests were also essential parts of the energy cycle until the Industrial Revolution—not just as material, but for fuel: for heating (fireplaces!), for bakers, and especially for glass and metalwork ovens. [1]
Apart from energy, land is also a limited resource even when used sustainably. And its use must be weighed against alternative land outputs, like food and material.
And regarding non-organic raw materials: at current volumes and speed, they’re finite , as usable concentrated reserves, that is. They are technically renewable, in general—you can isolate them from dust or extract them as molecules dissolved in seawater—but that takes massive energy input, which again must come from land-based (solar) yields. That would be the honest, sustainable way to use non-renewable resources. You could call that the biobased route for minerals and metals.
And so, when it comes to sustainability, there’s no option other than a biobased future. Living off the land and its annual surplus. From regrowable resources, and flowing energy.
Note: More on this in my latest book: The Space Time Economy, (embodied) Land as the capital for Post fossil living (https://www.ribuilt.eu/product/post-fossiel-leven/). I’ll be writing more on my blog page about raw materials and showing how much of each is annually available. The first piece already appeared also on LinkedIn: about Copper.
Note on humans vs horses: Horse: 10% useful, Human: 20%, from The Servitude of Power (2).
This aligns with Smil (3): While domesticated animals were important, the energy delivered by human muscle remained far greater.
Only for the strongest draft horses does Smil find slightly better efficiency: a horse eating 4 kg of oats per day consumed about the same grain as six people, but could replace the power of at least ten strong men.
That also depends on diet and land use. A horse needs about 1 hectare for food, a human with a vegetarian diet only about 1,000 m². That’s a factor of 10! So you end up 1-to-1: one horse = 10 human labor units, but you need 10 times the land. And that only counts for the strongest horses, and we’re not talking about the strongest humans. Add losses from stabling and infrastructure and the net output of a horse drops below humans. Not to forget that a horse must be guided by a human!. Which reduces the horse effect even more. So on average, we can reasonably assume a human delivers= more usable energy than a horse. I’ll stick with the numbers from Servitude: twice as much.
- see previous blog, https://www.ronaldrovers.com/metals-are-regrowable-07-kg-ha-year/ , and the new English version book: The Space Time Economy, (embodied) Land as the capital for Post Fossil living. , https://www.ribuilt.eu/product/the-space-time-economy/
- The Servitude of Power, Jean-Paul Deléage et al.
- Energy and Civilization, Vaclav Smil
