That is a very good question, but it is also the wrong question. The better one would be how are we collectively going to avoid nature doing it for us?
Because I don't know what the solution is but I do know that the alternative is going to be no fun at all. One possibility is that we all end up agreeing that we should at least try to reduce our numbers. My parents brought me up with 'replacement' numbers so that we'd end up with a steady population. I'm not so sure if that was wise. And I'm aware that there are many predictions out there that our numbers will eventually top out (they will, either because we do it ourselves, voluntarily or because our resources will run out, an exponentially expanding population in a fixed environment always ends in collapse).
But unless we manage to massively reduce our impact on the environment I don't see a way for the increased consumption and eventual survival of our societies as we know them today. In another comment someone offhandedly asked whether we should all want leisure yachts or not. The obvious answer to that is 'no'. But we probably also shouldn't all want vehicles and the ability to transport ourselves to the end of the world on a whim. Hard choices are ahead of us, the time for easy answers is long behind us.
This has been my "thing" for some time. Now, carrying capacity for Earth is a function, and one of the arguments is lifestyle, but I believe that we are beyond most values of that function for anything beyond "miserable and half-starved." The population will drop. We can do it or Nature will do it for us.
Nature will be wanton, cruel, perhaps overshoot. It will be ugly and horrific. We will not be left in great shape. The only fairness it will possess is unpredictable randomness.
Or, we can do it. Harsh. Belt-tightening. Unpleasant conversations. Lengthy debates about worth. Whole societies wanting their turn at the trough. Deprivation. Lifeboat politics. The Cold Equations in a hot, hot world.
These “unpleasant conversations” have been universally the powerful talking about how to genocide the powerless. Frankly, I’d rather nature do it than follow the population control proposals we’ve seen.
Everybody who decides that what they need to do is kill extremely large numbers of other people can just off themselves instead.
See, this is what I am talking about. You immediately leap to the problems of the past as a way to misinterpret what was said. This is why people simply cannot agree on a way forward and why Nature will be doing it for us. Some have even codified this into an ethical stance.
And so the scavengers will feast and the plagues will bloom again. And because no-one will agree, we will have little local wars over resources. Maybe someone will grab a warhead or two. Technology still keeps happening, so expect at least one plague to be targeted. And some group will have a "if we can't have it, nobody can," so a self-irradiated country will get to keep a resource out of some other group's hands. You'll get real genocides, then.
Nobody wants to participate in the one way of getting their hands bloody, pretending that they won't get bloody later on, up to the elbows.
You can feel free to detail your proposed way forward. But I don't think I've ever seen anything proposed that isn't active genocide of the less powerful, let along anything resembling justice. Maybe all the mass executions in your plan will be of wealthy and middle class Americans. You might surprise me.
... you really can't seem to figure out a third proposal for changing a population number from N to some number less than N? Have you excluded the middle that hard that only orchestrated murder or Nature's nasty negligence are the only things which appear to you? If you are legitimately that baffled, I am not sure we can manage to communicate at all.
Because I don't know what the solution is but I do know that the alternative is going to be no fun at all. One possibility is that we all end up agreeing that we should at least try to reduce our numbers. My parents brought me up with 'replacement' numbers so that we'd end up with a steady population. I'm not so sure if that was wise. And I'm aware that there are many predictions out there that our numbers will eventually top out (they will, either because we do it ourselves, voluntarily or because our resources will run out, an exponentially expanding population in a fixed environment always ends in collapse).
But unless we manage to massively reduce our impact on the environment I don't see a way for the increased consumption and eventual survival of our societies as we know them today. In another comment someone offhandedly asked whether we should all want leisure yachts or not. The obvious answer to that is 'no'. But we probably also shouldn't all want vehicles and the ability to transport ourselves to the end of the world on a whim. Hard choices are ahead of us, the time for easy answers is long behind us.