Yogourt is a traditional way of preserving milk and enhancing nutrition–and by making it I have avoided also making a literal wall of empty plastic yogourt containers. I have been making yogourt for many years now, and I think I finally understand it well enough to be able to laugh at my mistakes. So this is going to be a pile of trivia, some links, some science, and a summary of my current method.

How about we laugh first? Or skip straight to the instructions if you like.

Back in the day, I could not get my yogourt to be as firm as I would like so I started adding powdered milk. By increasing the milk solids, I did get firmer yogourt.

This is stretching my memory of the chain of events, but I think I then had the bright idea that I could make yogourt entirely from powdered milk, which would allow me to buy a bulk sack of dried milk and save money.

I also used to not pasteurize my milk, reasoning the bottling plant or the drying plant had already done that. This saved me a lot of electricity, and also eliminated the fussiest parts of yogourt-making, getting the right temperature at each step. Knowing what I do about food poisoning in the industrial food system, I am horrified I published this and I dearly hope nobody died after following my instructions.

But I understand fermentation a lot better now, google has more stuff in it, and also, we saw Sandor Katz speak.

Firm yogourt

Heat the milk up, and hold it at temperature for a period of time.

After years of googling and silliness with powdered milk I finally came across a paper on industrial yogourt production that talked about denaturing whey proteins by heating the milk to a temperature and holding it for a set time. Hotter is a shorter time, and cooler is a longer time. 

“The temperature/time combinations for the batch heat treatments that are commonly used in the yogurt industry include 85°C for 30 min or 90-95°C for 5 min”

This step may be adequately met in the traditional scalding stage, which may be why many people make good yogourt without knowing this info–whereas my newfangled low-temperature-powdered-milk yogourt was never very firm.

Here is a very readable article which has an interesting temperature method. They mention the scientists Lee and Lucey, which, if you google them, you will find a ton of papers on yogourt science, including the quote about temperature above.

If you want thick Greek-style yogourt, you can leave the yogourt in a fine mesh strainer so some of the whey drips out.

Reusing yogourt as a starter

The next mystery of yogourt is that when you make a batch using grocery store yogourt as the starter, it always seems to poop out after about a half dozen lifecycles. We saw Sandor Katz, Fermenting Guru, speak, and he said that is simply a consequence of commercial cultures.

And when you think of it, of course that makes sense. Our ancestors in yogourt-eating societies did not have labs and sterile workspaces to replicate and freeze-dry cultures. So either it was being refreshed from the environment, or the culture itself did not weaken after a few lifecycles. Katz says the latter. Some heritage cultures reproduce indefinitely, and some have additional properties favoured by different cultures, like the challengingly-textured Finnish Viili, or “ropy yogourt”.

I find I usually go out of town, or clean out the yogourt jar and eat my starter, or have some other life event interrupt me before my starter loses performance so I like to keep a few pouches of Yogourmet around. Yogourmet is a common starter culture available in better health food stores, often in the refrigeration section. I would expect you would find it in “ethnic” stores as well, like Greek, and maybe Indian. It comes in a box with several pouches of freeze-dried culture.

Heating tips

The basic rule is to heat milk slowly and cool it quickly. This prevents burnt flavours, and reduces the chances of pathogens infecting the milk as it cools. At this stage, milk is warm, wet, and full of protein, so it is a bacterial playground. Ice or cool baths might be used in cheesemaking, but for yogourt I just wait until it has cooled down naturally. The milk will be inoculated with billions of acid-producing bacteria that create an inhospitable environment for spoilage causing bacteria.

I have fermented yogourt in all sorts of ways. I have a giant Korean cooking thermos–a thermal cooker–which does a great job, I have wrapped blankets around pots, I have tried a crockpot, I have made a giant bain-marie, some people use a sous-vide. I had a two litre electric yogourt maker–the multiple tiny pots do not suit our eating style–and it worked great until it died.

But the best by far is our current house, which has an old gas stove with a pilot light.  It holds a wonderful incubating temperature inside the oven, so after I have inoculated the milk, I just put the pot inside the oven and walk away.

Lastly, here is an amazingly useful tool for making yogourt and cheese. This thermometer’s alarm will sound for both High and Low temperature settings, so it will tell you when your milk is hot enough, and then it will tell you when your milk has cooled enough for inoculation. This just saves a ton of fussing and allows me to do other things without boiling over or forgetting milk until it is too cold.

How to make (firm) yogourt

I typically make two litres of yogourt at a time, as it keeps nicely.

Over low to medium heat, warm milk to 95°Celsius (205°F) and hold it there for five minutes.

Let the milk cool to 45°C (115°F), then inoculate it with a starter. For starter, use one pouch of Yogourmet or a couple of teaspoons of yogourt per litre of milk, and whisk thoroughly or blend with a stick blender. If you are using a heritage culture, experiment.

Incubate the inoculated milk in stainless steel or glass container at 45°C for four hours. Incubating yogourt for a longer time makes it more acid, not more firm. I like sharp yogourt, so I often make my yogourt at night and take it out of the warm oven in the morning.

Congratulations! You have made yogourt–just chill and enjoy. I use it most in smoothies, and as a sour cream substitute for perogies. I love to drink Lassi, with cardomom and rosewater. And labneh is seriously easy and wondrously delicious.

There has been some heartfelt times around the urban homestead recently. Our doe rabbit Apple had stopped producing reliable litters of kits, and so for the first time we put one of our breeding rabbits on the dinner table.

I have some precedents in my childhood, particularly when Abby the Goat finally got too old. Abby was a great goat, a good mother, a productive milker, and a lovely person to be around. She was so old, by the time my family killed her, that she was sure to be tough as an old boot, and so we turned every bit of her into Ground Goat. Many the dinner of spaghetti and meat sauce came with a fond remembrance of Abby and a story of living with her.

So, I have some precedent, but I had never killed one of my own breeding animals.

Killing Apple was hard.

We tried a new kill method and that was excellent so Apple truly died as peacefully as you could imagine, literally with a mouthful of clover.

To fill Apple’s spot we bought Lucia, a piebald doe—what the rabbit breeders call a broken colouration.

Lucia came bred, which is maybe good or maybe bad because we still don’t know if our buck Apollo is part of the problem. Lucia is not so used to human contact and charges quite a bit. But she has quickly learned that the green deliciousness we bring is not to be feared.

And then Lucia kindled—a litter of one small kit.

So it begins.

…

I guess someone who “produces” rabbits would have other litters they could introduce little Bun-bun to, so it would be warmed by the cuddle puddle of cuteness.

Or perhaps someone who produces rabbits would have just snapped Bun-bun’s neck and tossed it on the shit that accumulates under the cages in a production barn.

Carmen brought Bun-bun in at night, and tucked it in a nest of Lucia’s belly hair and straw, so it would survive the chill. In the morning, she took it outside to nurse.

I say it because after several days of this, Bun-bun died, and we never sexed it to know if it was male or female.

We tried to keep it alive, knowing a single kit would usually die. Next time we will try something else.

 

Bun-bun’s death occasions a lot of thought.

There was only one end for Bun-bun, and that was an untimely demise—though untimely is difficult to define, since in the wild Bun-bun may have died at birth or within days. Rabbits have many kits for a reason. If Bun-bun matured enough to venture outside the den there are eagles and hawks, dogs and cats. Foxes? Weasels? Mink? I don’t know. But like I say, rabbits have many kits for a reason.

On our homestead, Bun-bun would have spent four months being moved to fresh grass every day. It would have snacked on blackberry canes and carrot tops, as well as any dandelions we pulled from the garden. Bun-bun would have torn around on those powerful and delicious hind legs, frolicking in sunshine and reclining in rain—droplets beading on its fur.

Would it grow to be piebald like Lucia?

Anyhow. Four months, and then we would have put Bun-bun in our stew pot, probably in the Portuguese style. We would have scraped Bun-bun’s hide and tanned it to gift, or to work into something lovely.

Should I be sad? I am. As Stephen Jenkinson says, “You don’t have to like death, but you do have to befriend it.” I never like it, and I am tearing up and congesting as I read over these words.

Bun-bun would die regardless—by hypothermia or predator or the stew pot or just old age. But I am sad that Bun-bun never knew the taste of fresh clover, or the warmth of sunshine or the joy of leaping.

So, Bun-bun got a tiny shroud of organic cotton. I dug Bun-bun a grave many times deeper than its little body, and laid it carefully on soft sand. Carmen poured it a final meal of milk and sang laments in her ancestor’s language for its short life. I filled the grave in, taking care to pack the soil so Bun-bun would not be dishonoured with soil sinking in an unseemly way. And then we laid rocks in a careful pattern, with big rocks at the cardinal directions and one particular rock in the middle which was just about the same size as Bun-bun itself, though much heavier than that poor, cold little body.

Addendum:

I wrote this post a few months ago, and in our rabbitry some things have changed and some have remained the same.

After Bun-bun died we mated Lucia and Apollo and Lucia bore a litter of six lovely kits. These kits are practically a high-school genetics class, showing the combinations of their black father and piebald mother—one black, one white, three piebald…and one very beautiful light silver.

A couple of weeks after their birth, I found this gorgeous silver bunny dead and stiff out in the run.

So a little more about rabbits…

A few weeks after breeding, we give our doe a nest box and a pile of straw. As she gets close to kindling she begins tearing around with mouthfuls of straw, like a comical moustache. She builds a straw burrow in the box, and as she gets very close to kindling, she pulls the softest hairs from her belly to line the nest. Born blind and hairless but for a light down, this nest keeps the litter warm until they can walk.

The doe will jump into the nest box once or twice a day to nurse the kits. Unfortunately, sometimes a kit will stay latched on the doe’s nipple when she jumps out. Rabbits do not have the instinct to pick the kit up and put it back, so if the kit is too young to find its own way back, it will likely die.

As did this fine silver kit, carried away from the warmth of its litter mates.

As fate would have it, I found it after the Trick or Treaters had all gone home on Hallowe’en.

We were tired, but it was obvious to me that there was no better time to return this little kit to the soil than when the veil between worlds is at its thinnest. So I dug another deep grave near the ash Carmen calls her Grandmother Tree. We wrapped the kit in a clean square of organic cotton from an old sheet that has now provided the shroud for several animals. We sang and drank whiskey.

And then, out of the darkness—Christmas Carols.

I guess a group of people had costumed themselves as carollers, and were singing for their candy. It was eerie and wonderful and hair-raising; I feel quite sure that little silver one was carried safely across.

So, there has been more tears than tastiness in our back yard, but that is how it sometimes must be. I have written a bit about this before, and I frequently struggle to put my feelings into words.

I think if we would like to be “sustainable”, if we would like to find our harmonious place in the order of things, we need to spend a lot more time intimate with the life and death of our kin, both human, and more than human. Raising rabbits is not our dominant source of protein, and it likely costs more in feed than it contributes to the grocery budget. But it very much makes me human.

 

 

Sustainable means able to be sustained, and the alternative, then, is things that are unable to be sustained.

What part of unable to continue suggests we continue right down the same path? It is like my whole culture is gaslighting me because I feel so crazy.

Putting a finer point on it, I have long been a critic of vertical farms, most recently in Vertical farms: the greatest hope for cities, or a band-aid on a sucking chest wound? 

Salon also posted Enough with the vertical farming fantasies: There are still too many unanswered questions about the trendy practice.

But over at TreeHugger today, the tireless Lloyd Alter gives vertical farms a little love after nearly a decade of criticism, with I was wrong about vertical farms; Aerofarms shows how to make them really work.

Aerofarms has apparently avoided many of the things Lloyd has criticized in the past: the farm is in an abandoned factory, the growing racks are stacked very high to get more square footage, the plants are grown hydroponically in a fabric medium so consumption of nutrients and water can be tightly controlled to eliminate waste, and LED lighting is used that can be tuned to the specific colours the plants need for optimal photosynthesis, thus reducing energy use.

Aerofarms is a classic Less Bad is not Necessarily Good solution, in which efficiency serves to distract from the finitude of our planet.

Falling from 500 feet may be “less bad” than falling from 1000 feet, but you are still dead momentarily after impact. 

Today, we spend 10 calories of fossil fuel energy to produce one calorie of food. Efficiency might allow you to use eight calories of energy to produce one calorie of food, but you are still losing net energy at a shocking rate. It is Not Good.

Before fossil-fueled farming, it was easy to see which farmers used more energy than they produced—they were the dead ones. With only their own or their animals’ muscles to power a farm, the chain of cause and effect was very direct.

In Salon, Stan Cox calculates:

producing America’s annual vegetable crop (not counting potatoes) in vertical systems under lights would require well over half of the electricity this country generates every year, and that would crank out 1.3 billion metric tons of carbon emissions per year.

Half of the electricity?! Hey, let’s be generous and assume they can double efficiency! Then it will only take ONE-QUARTER of all the energy used in the United States. And that is before we “succeed” in electrifying transportation and heating and cooling, thus radically increasing demand for electricity.

Which quarter of your energy use are you going to give up? Oh, you don’t want to give anything up? All right, I guess we need to increase capacity by 25%…

So, just a quick check-in on the facts:

• The US energy mix is 90% non-renewable, while globally, energy used is 80% non-renewable. Replacing that energy with renewables is going to be a significant challenge—a challenge many analysts characterize as impossible.
• Various IPCC reports and international accords agree Greenhouse Gases need to be cut sharply and very soon. 80% reductions by 2050 is one common target.
• Even still, these 80% reductions are widely seen as inadequate to avoid catastrophic climate change.
• James Hansen predicts a sea level rise of several meters in the next 50-150 years. His position is controversial, but he has a history of conservative conclusions.

Given these facts, let me sketch some vertical farm scenarios regarding the electricity used to power the lights, pumps and filters, and whatever CO2 producing devices they are enriching the atmosphere with:

Dark Green Reality
In this scenario, let’s assume we look at whole systems and determine the most important response to climate change is to radically slash material and energy use. Energy is allocated with great care to only the most important tasks, like the digital archiving of certain very valuable research texts, powering infant incubators, and very small amounts of pumping and other services.

Since sunlight falls on fields for free, it is immediately obvious that generating electricity to power lightbulbs to grow salad is a fool’s choice. Humans choose a more local and seasonal life, following and obeying the rhythms of nature. Birds chirp in every tree.

Bright Green Utopia
The electrification of the ‘developed’ world accelerates, with champagne corks popped for every new Tesla model. The developing world follows, with electric cars, air conditioners, televisions, light bulbs and computers reaching billions more people then ever before.

To power all this requires damming every trickle of water on the planet, while resource extraction and manufacturing for solar panels and windmills still need huge amounts of fossil fuels. Coal plants stay online to cope with differences between demand and renewable supply (caused whenever the sun goes down), and there is a huge surge in (non-renewable) nuclear power development. The downwind pollution from nuclear reactors and fuel mining continues to cause cancers and birth abnormalities, and the spent fuel continues to have no place to be safely stored for the lifetime of the danger. It takes a century, but Aerofarms factory is washed away by rising sea levels.

Hell in a Handbasket
Increasing climate chaos activates human lizard brains at a mass scale, causing people to double down in a hedonistic fuck-it—a sort of perpetual Black Friday riot. All of this consumption requires massive amounts of electricity, so coal plants are spun up to maximum and construction starts on dozens of nuclear plants, as well as fuel mining and processing plants.

Global average temperature soars, ice caps suffer catastrophic melt raising sea levels dozens of feet within decades, not centuries. One billion people are displaced and massive urban areas including New York City and Mumbai are inundated. Aerofarms original location is washed away.

Business as Usual
On our current trajectory, BAU is not wildly different from the Hell in a Handbasket scenario.

There is no way to make vertical farms good. Neither our current model of transporting food great distances nor vertical farms are good responses to overpopulation and urban concentration. Maybe they are less bad. Maybe.

The public discourse, politicians, academics, journalists, scientists, most seem to be blithely washed along in the flood of business-as-usual. The plan—the actual policy—seems to be hoping a knight in shining armour will ride in to save us. This is enormously frustrating for me.

“Would you like to get kicked in both knees, or just one knee?”

“Erm…. I would like to not be kicked at all…”

We are talking about systems that rely on non-renewable resources, and are therefore impossible to sustain. The immutable forces here are the laws of nature. If our agriculture is not sustainable, that means it will not be sustained. That means it will end. That means people cannot eat it.

Less Bad is slow death.

But it is true, talking about what is Less Bad and what is Good obscures the reality of the situation a little.

The challenge is that while Less Bad is slow death, Good is increasingly looking like different death, at least in the short term. We show no sign of voluntarily realigning our society and our culture to follow the laws of nature. Rather, we continue to throw energy, materials and technology at problems. This makes a reckoning inevitable, and it is hard to see how an involuntary reduction in population can be avoided. It sure looks like truly sustainable agricultural practices that could feed humanity will only be widely adopted when we have exhausted all of our Less Bad options.

Now, slowing bleeding is always a good idea, but we are way past the cut and scrape stage. When medics perform triage after a catastrophe, they leave some people bleeding because they have no hope of survival and the bandages and personnel are needed for people who might live.

So, should we focus time and attention on infrastructure that, as these rough scenarios show, cannot endure? Personally, I try to work for things that are Good.

Which is not vertical farming.

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.

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.

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.

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. 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.

***EDIT*** This just in from Salon. There are some actual studies with actual numbers in this article. Conclusion? Vertical “farming” is a giant energy loser.

http://www.salon.com/2016/02/17/enough_with_the_vertical_farming_partner/