I'm not saying we need less population at present.
I'm just saying that at some point the cost outweighs the benefit. And humanity has been trying pretty hard to go toward that point.
Do you really think it will always, always be better to have more people? If you say no to this, then you don't get to say we're on different sides of the line. If you say yes, then you need to explain how that's physically possible.
Not that there is anything wrong with disagreeing with me on this.
Two point as a taste:
1. One way more people is always better is in invention. Ten billon heads invent more than one.
2. People always worry that with more people there will be food shortage. They are also always empirically wrong. Because food is made by people! Twice as many people means twice as many farmers!
Inventions are great but they can only do so much to improve land use.
I don't think we even have a way to put one billion people to work on optimized farms. More labor won't lead to more full mouths.
As an example of costs catching up, going from 20% of land to 30% of land needing to be optimized farms used to feed people directly? That's easy enough, and those numbers would support more people than we have today. Going from 80% to 90%, however, is extremely worrying. And we could go from the former to the latter and past it very fast too.
