The first statement does not follow automatically from the second.
It is not currently run in a sustainable way. It can be, and people are trying change it so it is sustainable. This is hard, but does not appear to be impossible.
which creates something of a tautology. Ability to maintain a population in the long run implies 'sustainable'. I guess that given nutrient vats and fusion power we could have a sustainable population of one trillion.
It's worth considering what the point of having so many people is....
>Once you answer those questions, is there a number of people you'd like to propose as optimal?
That's a good question. I'll take a shot at it even though you're not really asking a question but making a point.
Let's say that the one thing that people bring to the table is intelligence and the ability to design complex systems, it's something of an end-run on evolution.
How large a population do you need to build modern semiconductors, discover exoplanets, solve physics problems, do a passable version of the arts?
I would guess something on the order of 500M-1B which is roughly the number in 1800. You get most of the good and lose most of the bad if you're even slightly careful. The edge conditions of atomic war or a truly large nuclear incident still exist but the rest of our sins cover up well over time with that population.
> It is not currently run in a sustainable way. It can be
Can it? That remains to be seen. So in the meantime I would say we are already overpopulated.
To be fair, your statement probably means that we have the resources and technology to run the world in a sustainable way, and I would agree with that. But then we also likely have the resources to end hunger, poverty and war, yet those have never been the world’s priorities.
When will it be a priority for humans to run the world sustainably? Who knows. But right now it’s definitely not sustainable.
> But then we also likely have the resources to end hunger, poverty and war, yet those have never been the world’s priorities.
And yet, all of those things declined; in the case of poverty the decline is in both absolute and relative terms.
Certainly more needs to be done in all of these things: we only succeed when we reach the destination, not just when we walk the path. Conversely, every step on that path brings us closer to success and is a reason for optimism.
The world is already overpopulated. We just haven’t completely destroyed it yet.
The way we currently run the world is not sustainable long term for even the current population.