But there are no other solutions, believing that technical advances can keep exponentially growing resource demands in check is delusional. If some process is currently 20 % efficient then there is at most a factor of 5 to be gained. And that assumes 100 % efficiency is attainable to begin with while it is not unlikely that physics sets a limit on the maximum attainable efficiency of say 50 % or 80 %. A population growth rate of 1 % per year will eat up a factor of 2 in improved efficiency in 70 years and there are only so many times you can squeeze out another factor of 2 before you hit a hard limit.
It is not lazy to try to control population growth, it is the only viable longterm solution because technology can not solve this problem. The goal must be to stop population growth or, for practical matters, increase the doubling time at least to the order of millennia. That is why I gave the example with colonizing the Milky Way, to make clear how bad the problem is and how infeasible technological solutions are.
I guess another obvious point is: there isn't a question of whether population growth will be controlled, it's more a question of how exactly that will happen. I.e., is it something we choose, or is it forced on us?
less desirable options: uncontrolled global civilisation collapse with rapid decline in living standards and population, nuclear war, etc
more desirable options: intentionally adjusting lifestyle / affluence in western countries, non-coercive methods of population control (e.g. better healthcare, increased access to family planning, increased opportunities for women to participate in education / economic activity, etc), less focus on short-term appropriation of wealth
I wanted to mention this, too, but then decided to keep it short. Actually I think population control is not really necessary because many parts of the world have already reached sustainable fertility rates - or non-sustainable fertility rates in the other direction - due to human development. And I don't see why regions with fertility rates above 2.1, especially Africa, would not follow that path assuming we manage to shrink the development gap.
One could ponder whether it would make sense to use population control in addition to improved technology and development to make the ride across the world population peak smoother, to make the peak lower and happen earlier. There would almost certainly be at least some benefits to this, but given how long political debates about that would probably take, never mind implementing and enforcing the decisions, there might actually not be enough time to do this and get some noticeable impact out of it.
As long as it looks like the world population will peak around the end of the century, go for technology to make it as pleasant as possible, but if the outlook indicates that the world population does not peak or at least stabilize in the foreseeable future, then population control is really the only way or it will become pretty unpleasant as you indicated in your first scenario.
Reminds me of the scene in The Matrix where agent Smith tells Morpheus that humans are like a virus: they move to an area, and when all natural resources are consumed up they spread to another area.
I was thinking exactly the same thing. I think [one of] the critical problem[s] is that we continue to think through the lens of resource consumption until resources are exhausted. I think it'd be pretty interesting if we began seriously evaluating ideas through the lens of resource creation on some fronts, and denying resource consumption on other fronts. Of course, I don't believe this will be achievable while the world continues to celebrate and allow the capitalist modes of production and value extraction.
Is there a recognized exhaustable availability of resource X? Then we simply don't allow that resource to be used as a means of capitalist value extraction from a planet. The resources belong to the commons, and we must shift away from allowing profits to guide the use of raw materials.
I look at, say, the last century of the automobile, and cannot avoid wondering just how different our lives would be if we'd bypassed the idea of placing a couple tons of metals and plastics in everyone's driveways. What else might we have used those materials for, if we mandated that using them had to be done in a way that benefited a large number of people with the same material cost. This really goes for nearly every consumer product made available to the markets.
I don't think we'll be able to come up with viable long-term strategies for handling population growth, and providing a high quality of life to all members of that population, until we move beyond status-driven consumerism and the capitalist economies that create and depend on them.
It is not lazy to try to control population growth, it is the only viable longterm solution because technology can not solve this problem. The goal must be to stop population growth or, for practical matters, increase the doubling time at least to the order of millennia. That is why I gave the example with colonizing the Milky Way, to make clear how bad the problem is and how infeasible technological solutions are.