I sometimes find myself making negative comments about vertical farming. This happened again today, and the facebook friend to whom I responded replied very openly with, “Well, what then? Green belts?”
So rather than continue my terse and impatient crypticism on social media, I will try to respond comprehensively. My analysis, as with all analyses, rests on a few assumptions:
Our planet is finite, and receives no new inputs important to human timeframes, except for sunshine.
Since the planet is finite, everything on it is also bounded. Nothing can grow forever, and nothing can be extracted forever.
Please note that I said extracted, which is different than harvested. We extract nonrenewable resources, like oil, coal, copper and iron. We harvest renewable resources, like apples, wheat, chickens and salmon.
We can harvest extractively. So, if we catch too many salmon, the salmon cannot renew. This causes depletion, extirpation and extinction. But if we harvest less than can be renewed, that harvest is sustainable.
For all that people like to justify their behaviour by throwing their hands in the air and saying, “But what does sustainable even mean anyway?” it has a very simple meaning. It means, able-to-be-sustained. That means essentially forever, which to humans is probably 1000 or 10,000 or 100,000 years. Whatever.
That nothing can be extracted forever is basic math. Even if our planet was made of solid gold, we could only extract a maximum of one planet’s worth of gold from it.
But nothing is solid, gold, or anything else. Everything is mixed up with other things: coal is mixed with rock, fish are mixed with ocean.
Being practical, we like to start with extracting the richest, most concentrated deposits of a resource, whether that is coal, copper or whales.
We start with the easiest, and then we make some specialized tools which help us really increase productivity—so then we roar through the easy stuff, and start working on harder stuff and that slows us down a little. And then we slow down a lot. This is Peaking; the most famous example is Peak Oil. This is not a theory, it is math.
The shorthand for this in our daily life is the 80/20 rule. 80% of the work gets done with 20% of the effort—and the last 20% of the work takes 80% of the effort. That is nice, but it really is probably more like the first 40% takes 10% of the effort and the last 60% takes 90% of the effort—except the last one or five or ten percent is actually just impossible for us to extract no matter what we try.
So, if we have a field of potatoes and the desire for a plate of french fries, we can easily dig a few spuds by hand and we don’t care if we miss a few. But if want to maximize our profits by harvesting as many of our potatoes as possible, the 80/20 rule begins to bite. It seldom makes sense to pay humans to harvest 100% of the tubers; the payback on finding the last few—or the last many—is just not worth the labour costs.1
Faced with the high cost of labour it seems to make sense to build a potato harvesting robot. An automated—or lightly supervised—machine can outowork humans, and never asks for holidays or a raise. So that is great. We harvest more spuds and waste less food. We “spare” humans the toil of harvesting.
But at what cost?
The machine runs on oil, a non-renewable resource. It is made of steel, and aluminum, and copper, and fabulously rare minerals, all non-renewable. Furthermore, all of those materials were extracted with machines that run on oil, were refined in coal furnaces, and manufactured with more oil or coal.
And all the extraction, refining and manufacturing machines were made of materials extracted with oil, refined with coal, and manufactured with coal or oil. It is like a terribly polluting—and unsustainable—M.C. Escher drawing.
If something is unsustainable, well that means it is unable to be sustained. All we have left to discuss is the date of the funeral. To be fair, the funeral may be years, decades, or centuries in the future—but if you see a black suit or dress on sale, you might want to snap it up…because if you use non-renewables at any rate, they will eventually effectively disappear.
Lastly, I want to mention the principle of bankruptcy. If you spend more than you make, you go out of business. If a coyote spends more calories chasing rabbits than it earns when it catches rabbits, it starves to death. If a plant transpires more water through its leaves than it collects through its roots it wilts, and can die.
And if it takes more energy to drill for oil than you get out of the oil, you stop drilling.
The Beverly Hillbillies could spend one barrel of oil energy and extract 100 barrels of oil for sale—this is the magic of fossil fuels, they are fantastically concentrated. One gallon of gas contains the energy of something like two weeks of human labour.
But of course we burned through that pretty fast, and more recent drilling is closer to a 30:1 ratio. The oilsands are as low as 3:1—that one barrel of energy nets only two more.
Some biofuels may even be negative, they use more energy than is extracted. They exist, like industrial potatoes, thanks only to a massive, historical and onging subsidy of oil energy. Without the built industrial infrastructure and overseas resource wars, they would wither away.
And the same goes for our green darlings, solar, wind, tidal, et c. They are all harvested with machines of non-renewable materials mined, refined and manufactured with oil and coal. They are not able to be sustained.
So maybe I can talk about vertical farms now.
The notion is that dense cities can grow some of their food and cut down food-miles, the impact of transporting foodstuffs from field to plate. Secondly, by growing up perhaps we can avoid growing out, and thereby leave more land for other creatures. And thirdly, by hermetically sealing out insects, the use of pesticides can be hopefully eliminated.
Well, local eater though I am, I know food miles are not the greatest impact of food, by far. About 4% of the impact of your food lies in transporting it to your plate.
And what does the remaking of a farm on the vertical plane cost?
Farming benefits from rain for the plant, and the blessed sunshine, and the sweet soils, full of worms and bugs and bacteria and fungi, all of which add fertility.
Vertical farms build a concrete box to keep all that away, and so they must replace it all with lights and pumps and synthesized chemicals. Mined, refined and manufactured. And then after the manufacturing, the lights and pumps must be operated with power generated from coal, gas, hydro and nuclear. And those power plants are mined, refined and manufactured…
So everything that nature gives for free, a vertical farm excludes and replaces with an expensive, non-renewable, unable-to-be-sustained system that relies on subsidies from resources kept affordable thanks to foreign wars. In no way do they produce as much energy as they consume. And so, ultimately, they are destined for starvation.
Now, there are a few things that consume more than they produce which we continue to subsidize—babies spring to mind—so maybe we could choose to subsidize vertical farms because we like fresh lettuce, and want space for wildlife.
Maybe, But they do run on non-renewable materials and energy, and nobody who knows anything about manufacturing thinks that is going to change anytime soon, or that it is necessarily possible at all. I don’t find the idea of long-term energy subsidies for vertical farms to be very credible.
The use of non-renewables is not-able-to-be-sustained. And the use of renewables to grow food is, well, farming. As in fields. With sun and rain.
Well, what then? Well, this is not a problem that can be fixed, it is a predicament to be carried.
The question itself contains the perspective of Empire. Everything must bend to us, everything must work out for us, our way of life is not negotiable. We have upwards of seven billion souls on this planet, and they all want iPhones, therefore we need vertical farms.
History shows that empires cannot escape the math of bankruptcy, and so far they have all fallen. The only way out of this without confronting our desires to continue our highly subsidized life of ease and privilege is to seek a Higher Power—a miracle is needed.
For the rationalist problem solvers among us, that higher power is usually science and technology.
For example, if somebody develops a nuclear reactor that can run on pocket lint, we will be essentially liberated from constraints on our energy use. Realistically, that does nothing about the many other non-renewables except increase the length of time we can scratch around in the dust for crumbs. But most-importantly, it is a hell of a way to plan for the future. We are literally saying, “We don’t want to deal with reality, so we are going to continue doing whatever we want, and trust an angel will bring us a miracle.”
This church points to past innovations as proof we will science our way out of this jam. This ignores history. Various forms of fossil fuels, for example, have been known for millennia—they just weren’t seen to be useful. Many centuries later, given a huge untapped resource, well-known and lying around in plain sight, we did develop the massive burning of oil products that finally docked the whaling fleet. 2
Now, if they hadn’t developed petroleum products, we would have stopped using whale oil anyway for the simple lack of whales. That is the math. Whales were in steep decline before the first oil well was drilled.
But what we don’t have today is a massive store of concentrated energy, lying around in plain sight. We do have several kinds of very diffuse energy: nuclear, solar, wind, etc. Because of the energy, materials and infrastructure required to concentrate that diffuse energy, these have a much lower Energy Return on the Energy Invested than a nice barrel of oil.
This means there is less surplus. If your investment returns 7% instead of 5%, you have more surplus and you can do more things. If you have less surplus, you can do fewer things. So, in a world of diminishing returns on our energy investments, in a world in which we have and will continue to have less energy to spend, why would we build a box to keep nature’s free services away from our plants, only to replace those very things with energy-hungry lights and machines?
This is not able-to-be-sustained. And so it will not be sustained. That is the math.
Now, in the short term, we may get caught up in the Green Fever, and slap vertical farms in some parkades and vacant lots. It is a short-sighted sort of math, but it is good-hearted. 3
For myself, I am interested in longer-term thinking. I am not interested in advocating for systems like vertical farms, which will consume enormous amounts of concrete, steel, copper and plastic, and will eventually go out of business. Why would we sink precious resources into a system that cannot be sustained?
There is real, important and durable work, sustainable work, that needs to be done. If we want to increase the food grown in cities, start replacing decorative street trees with fruit and nut trees. Advocate for systems that manage our food scraps with chickens instead of with diesel trucks and loaders. Support your peri-urban farmers for your tender greens, and ask your grocer to contract with local farmers. Start thinking about what is able to be sustained. Think about what we can have, not what we want to have.
About a century ago, New York City received most of its food from within seven miles. So yes, cities need green belts. This is a durable model that has worked for humanity over the long term. Most importantly, traditional intensive farms can produce more food than they require to operate. They can be sustainable.
Ours is far from the first civilization to face the fact that our systems cannot grow forever—nothing can.4 Vertical farms are the answer to the wrong question. The question is not how many technologies we can deploy to resist change, no matter what cost to ourselves and the ecosphere. The question how do we live joyfully within our fair share of this planet.