Every estimate I've seen points to a minimum requirement of ~1 hectare of arable land to feed one human for one year (on a minimal vegetarian diet) and that estimate assumes highly productive soils and minimal crop loss due to insects, drought, or flood.
The idea with permaculture is that you minimize (ideally eliminate) the need for fertilizer, herbicide and pesticide imports using effective composting and crop rotation (biological nitrogen fixation) and integrated pest management (raising insects that eat crop pests etc.) and water recycling systems and so on.
Scaling this approach to tens of thousands of acres for reliably feeding even a medium-sized city seems challenging, but there appear to be some 1000-acre permaculture farms out there. However, yields are likely to be lower per acre with this approach as practices like using high fertilizer imports to allow double-cropping don't fit the permaculture model.
It's worth noting that permaculture is not just about farming or homesteading. The point is mostly to have a balanced ecology that humans can live in. You can still have large farms, small farms, or no farms, and do permaculture.
The big mistake we made was building large cities that required moving or reshaping the land, water, animals and plants to support large cities. There really should not be this many humans in the world, and certainly not with as many huge cities as we have. We're becoming a species dependent on a synthetic environment.
I find this idea of a "synthetic environment" kind of strange in a way. We crossed that line twelve thousand years ago when we started large-scale farming. That alone was a transformation of nature which immensely upset the previous natural order and caused human population to rise immensely. But I wouldn't really consider that artificial in a major way, and on some level we're also part of nature. I don't think we are any more artificial in building cities than bees are in building their hives. There is a difference, but not one which matters for this conversation, though I will mention that that difference has to do with the fact that we picture an idea in our heads before projecting it into reality through labour.
I don't think it's healthy to see the world as a struggle between the natural and artificial, because it's so hard to properly define. Humans are natural, making tools is in our nature, so is constructing shelter. I think the proper way to see the world is as this unity, humans exist within nature and act to transform it, as does every other animal species on this planet. The ecosystem would look wildly different did termites and bees not transform it for their own benefit, and similarly it is humans who transform nature in their own ways for their own benefit.
This does not mean unconditional support for human activity. Glass, concrete, and steel towers and spreading suburbs are terrible transformations of nature. They are terrible because of their destructive potential for no gain, they are unsustainable by nature, they upset the balance in a way which makes the land less fertile, less capable of supporting life in general let alone humans, and in the long term are a loss not only for natural diversity but for the human species as well. There exists a rift due to industrial agriculture where humans take from the earth and give back to it from the mountains and the bedrock while pushing waste into the oceans, which is unsustainable and which has and will lead to ecological collapses. This is but one part, industry in general, pollution, the carbon cycle, land use change and associated environmental effects, it all acts to lower the carrying capacity of this Earth in the long term. This is how I believe it is best to critique transformations of nature in this manner, because terms are easy to define, the unsustainability is scientifically provable, you have no such ambiguities as when you talk about artificial and natural as two entirely separate concepts.
This also gets you out of very bad ways of thinking. There is no "natural carrying capacity" for this planet except what it currently has. There is likely a theoretical maximum and some day we might hit it. What's clear is that we haven't hit it yet, we just
fail to push the current carrying capacity by transforming nature in an unsustainable fashion for short-term benefit. You can no longer say things like "There really should not be this many humans in the world", since it's plainly not true. There are supposed to be exactly as many humans as there are, because humans naturally transform nature to support themselves. It is our own nature, our species being, to take those gifts of nature and use them to transform them, through our own labour, into products which are use-values to ourselves. This is just as it is the nature of bees to pollinate and build hives, the nature of woodland animals to eat their hives and the flowers they pollinate, and the nature of elephants to topple trees to create for themselves a grassland instead of a forest.
It is not that there are too many humans, even with our unsustainable practices this planet easily currently produces enough food for ten billion to live well-off. It is not that there is artificial and natural, to make natural artificial is natural, because to transform nature is human nature. It is our current, wasteful and unsustainable transformation of nature, no different to those transformations that took place twelve thousand years ago except in its unsustainability, which has been been sucking the life out of this planet. But as humans, we have the unique ability to both imagine and then through labour project that ideal into reality, to once again transform what was natural to something which suits our needs. Our needs are, in the long term, sustainably keeping at the very least ten billion people alive, and permaculture is one of the ways in which we can both imagine that and start to bring it into fruition. However, our own relations and structures might prevent a total change in our transformation of nature in its present state, which is why political action is as important, if not more so, than homesteading or community gardens.
Idk man, I don't think overpopulation is an issue and I despise imagining that there is something uniquely bad about artificial things and that they are somehow different from nature. They are nature, their creation is our nature, and we ourselves are creations of nature. It's only how we have in the last few millenia, really even few centuries, been doing those transformations which is the true issue.
End of insane HN rant I guess. There's obviously no infinite growth, but we're also far from overpopulation. The world is not a Malthusian nightmare, it's not that resources cause population to explode and conditions to worsen, we can see that in the richer nations of the Earth where instead resources cause population to drop after a point. We'll naturally reach our peak well within the theoretical maximum carrying capacity of the Earth, that's my point. Permaculture is one important step on that path. Neo-Malthusians and genocidal maniacs and eco-fascists disgust me to no end.
The big difference between cities and honey bee hives is that bee hives have to work within the ecology, whereas cities don't.
Literally, honey bees can't exist unless their environment supports them. Their way of life has to adapt to the environment around them, not the other way around. This is made obvious in a number of ways: they literally biologically are adapted to make their particular type of home, their social structure is required to support said biology, they hibernate, they're susceptible to environmental damage and pests, they depend on a symbiotic relationship with flowering plants for pollen, etc.
Humans simply don't have any such limitations. If an environment isn't suitable to them, they just change the environment (a fairly novel thing in human history), or build something to support themselves and their lifestyle, rather than adapt a symbiotic relationship with their environment. Humans can pretty much do whatever they want regardless of the environment. This makes them highly adaptable, but also means they can parasitize the entire ecosystem until there's no resources left to adapt. The further they move towards collapsing ecology, the more dependent they grow on an ecology they create artificially to sustain themselves.
Therefore while bees can continue to thrive as long as the environment supports them, the environment can only thrive as long as humans support it.
There's no reason to suggest we will hit some peak only for it to drop off. We're not like parasites that are subject to an environment; we transcend the environment. We aren't limited by it. It's possible we will simply extinguish all natural resources (intentionally or not), and then either leave the planet or die off. There are no guarantees. Unchecked human growth really could kill everything.
Exactly, humans are free from limitations. When nature doesn't suit us, we have the capacity for transformation, just as bees have. However, we can choose any scale, even planetary. But that freedom is an illusion. There is no transformation of nature which happens without interference from the system around us. If we decided that the planet should be a couple degrees warmer for agricultural output to increase, we would inevitably find ourselves in an ecological collapse and a resulting collapse of agricultural output. It's just not something we can do. Nature itself is the limit, pushing beyond that means inevitable ecological collapse and resulting human collapse – we cannot eat without nature. Not that some chemicals can't be produced synthetically, but not nearly all. The massive expense we would incur over feeding just a couple of people with massive bioreactors to avoid interacting with nature at all would be prohibiting. We are, as are all other species, trapped within nature despite our capacity to transform it. This is because we are nature, not something that transcends it. We are the Lorax, we speak for the trees, we uniquely have both an imagination and the capacity to labour. There is evidence to suggest we will hit a peak - humans simply don't want that many children at some point after the elimination of scarcity. We know this, you can look outside and see it if you live in what they call the "global north" or "imperialist core" or however you want to refer to it. We don't know why, but it happens. Humans and nature are very much compatible, although it is true, that unchecked human activity could kill everything. Not even growth, just activity, and at a fraction of the current population could have already killed everything. It's not inherently human to take and destroy, that's just a necessity places upon us all by our current societal structure. We do it or someone else does it and we starve. But it does not have to be like this. The world is, again, not a neo-Malthusian nightmare which requires genocide to overpower for the sake of plants and animals which could less understand what is happening. We must, as we are limited, live within nature as part of it, transforming it, but our current transformation, necessitated by society as it is, is simply idiotic. There is no evidence to suggest that we are anywhere close to a "carrying capacity" or we will ever suck life out of the system and leave rather than simply glassing it and ourselves or learning to live with it. We cannot leave, this life would not grow anywhere else without immense struggles, it can only exist within complex ecosystems and taking them out of that context will destroy them. We cannot suck it out, for it is our own death as well.
The thing people don't realize is that we waste so much space and resources on useless crap.
1 hectate per person is easy to get in any suburban neighborhood if everyone can agree that a stable healthy food supply is more important than endless lawns or empty lots.
The resources are all there, we just grossly misallocate and squander them.
I think one could do with far less if things were optimised for nutrient retention (including human waste which often isn't allowed in many places).
In fact I think it's easy to produce enough for a person on far less than 1 hectare in my experience assuming one's climate is somewhat fitting. My tiny backyard produced more than I could eat last year albeit with barely any space for me to walk between the plants. It's doing it long term without fertiliser/manure that's difficult.
The idea with permaculture is that you minimize (ideally eliminate) the need for fertilizer, herbicide and pesticide imports using effective composting and crop rotation (biological nitrogen fixation) and integrated pest management (raising insects that eat crop pests etc.) and water recycling systems and so on.
Scaling this approach to tens of thousands of acres for reliably feeding even a medium-sized city seems challenging, but there appear to be some 1000-acre permaculture farms out there. However, yields are likely to be lower per acre with this approach as practices like using high fertilizer imports to allow double-cropping don't fit the permaculture model.