There's a lot more food once you stop wasting food land on raising non-human animals and cars.

And sprawling mansions with manicured gardens.

Humanity doubled each 43±6 years while tree cover loss doubled twice as fast to free up farm sites, to meet the needs for food and non-food. Say, all of the non-food farms can simply switch to food, to yield twice as much food, this transition's impact will vanish after only 20 years.

But crops need particular soil; harvesters need particular terrain. The wars on oil will further increase demand for agri-fuels and artificial fertilizers. Deforestation slows down, currently halving after 40 years which is desirable but pulls (violent?) growth stagnation towards present.

then you better learn about veganic quickly.

Animal food linearly translates to human food. In an exponential coordinate system, meat/vegan is almost irrelevant. Global nutrition depends mostly on artificial fertilizers that is, fossils. At scale, you can neither maintain a meat-based nutrition without fossils nor a vegan one.

Climate crisis comes still on top of this.

So be prepared for food from (low quality soil) graze land.

So we'll eat like Garfunkel's rabbit.

Now you understand the Sound of Silence.

I think you're mixing things up, where you assume that the past is part of an inevitable exponential growth in our future.

There are two exponential curves happening, neither of which is inevitably going to continue:

1. Global human population growth has historically been exponential across many periods of history. There are signs that this is slowing down and might reach a period of zero or negative growth, almost purely off of social changes.
2. Per capital consumption of resources has been growing exponentially since the industrial revolution. But when you dig in, that's largely only true of certain resources, and some rich populations have reversed growth for certain resources (coal in the West, beef in the United States). This is where the fight is, and where we can work to reverse the trendline for fossil fuels generally.

Humanity doubled each 43±6 years

From this source
, that really has only happened twice (48 years from 2b to 4b, and then 47 years from 4b to 8b). Before that, it was much slower (about 120 years from 1b to 2b). And might not happen again, where I doubt the world will ever see 16 billion living people on the planet, and where projections for 50 years from now are around 10 billion, with a peak and decline shortly after that.

The main work that needs to be done is on stopping the exponential growth in consumption of physical resources per capita, or the exponential growth in environmental damage per capita. And we're working on it: recycling loops of our raw materials like steel or lithium batteries or glass or copper, pursuing zero emissions energy sources, switching certain land use and ocean extraction to be sustainable indefinitely. There's a lot more to do, and we haven't been successful on every front, but the fight is winnable and losing isn't inevitable.

Gene therapy for regrowing teeth 👍

I wouldn't bother. Too few humans deserve even that, IME.

It's not linear, bud. The loss of calories to raising animals for food is about an order of magnitude.

Animals raised on grasslands only aren't going to replace the system, they're already maxed out and represent a tiny amount of the total "flesh pie". If you're arguing for deforestation and draining swamps to create more grazing land, that's just going to accelerate the climate heating. Also, the climate chaos and increasing heat will make this pastoralism a dead end since the animals will die from heatstroke, starvation and lack of clean water, along with various diseases.

Be prepared for eating plants exclusively.

A linear coefficient magnitudes above 1 is still a linear coefficient.

Let's argue which dead end comes first. Land, oil or climate? Please give some numbers.

No matter what nutrition you provide, population sucks it up. There won't be much of a human benefit by changing it. If meat production is impacted by climate itself and vice versa, we have another reason not to touch it.

We need to get rid of fossils, nutrition and fertilizers need to get rid of fossils for the global benefit of an affordable, liveable atmosphere, and a maintained population.

Social reasons for population stagnation may hold for present-time "developed countries" as they are currently sexually distracted and rather pessimistic otherwise. I don't think I can rely on that. Equatorial countries still maintain population growth of about 5% and rely a lot on non-vegan nutrition despite the heat and lower wealth.

There's a shitload of literature on food security, why don't you go read.

The energy relationships will always remain the same, matching trophic levels. We can get more food by eating straight from the primary producers: plants. No, marginal grasslands will not do.

Even going down for collapse, keeping the animal farming sector translates to more famine. And if you keep the luxury, that translates to more social conflict over luxuries, more mafia, more "leather underground", more secret animal farming and detouring of food.

Again, this has been known for a long time with history, not just theory. Here's a fun example from Germany: https://www.bostonreview.net/articles/troy-vettese-do-not-let-them-eat-meat/

That example is pre-Haber-Bosch.

The relationship remains the same even before industrial agriculture, probably more than with all the nitrogen cycle hacking.

Talking about collapse, I assumed a lot of deaths are involved. To avoid the collapse, a maintained N cycle hack is mandatory.

There are ways to adapt, perhaps enough to avoid collapse just from that.

Here's a good intro:

https://www.tabledebates.org/building-blocks/nitrogen-food-system