My views on this are unlikely to make anyone happy. They do not make me happy. I am in the very grim Club of Rome, "the 29th Day," group. Very pessimistic. I think the ship probably sailed by about 1950. We staved off Malthus here and there, but to do it indefinitely requires geometric advancements not just in agriculture but in literally every field in the supply chain, such as energy and mining, even physical space.

It's all about tradeoffs. The largest tradeoff is "population as a function of lifestyle." You can support a lot more miserable people in lousy conditions receiving poor medical care than you can one person living well. It's about resources expended per person. Even after you get hyper-efficient, it's still about resources expended per person. There's no escaping that reckoning ... you can delay it with marginal improvements to efficiency here and there, but once you've squeezed those out, it's "how well do you want this person to live?"

While you can briefly support a large populace, you might not be able to sustainably, over generations, carry that population. This is the "carrying capacity." Put bluntly, you can have a lot of goats on an island munching away faster than the vegetation regrows, but their populace will not collapse until the vegetation is gone. And I believe that our carrying capacity for "living like Americans" is far under a billion.

In 1950, our populace was about 2.5 billion, but "living like an American" was a lower bar. Now we're approaching eight billion, quickly, and the USA (as well as much of the first world) has been quite busy exporting lifestyle aspirations via Hollywood or their respective film industries. Even if we could snap our fingers and cause a zero population growth rate, more and more of that populace will have growing aspirations.

My guess is that around 1950, civilization could have adopted some kind of one world government with some very drastic control over reproduction and allocation over resources. By 1990, that control would have been that much more draconian. By 2030, the kind of control required to drop the world to that carrying capacity would be unconscionable by almost any ethical standard other that "have a functioning civilization still in 2150." It's a kind of grim Orwellian dystopia with no chocolate rations to lie about, and no spare capacity for war, one in which a human's viability would be solely decided by their ability to produce calories and resources in excess of what they have already consumed, wherein people would have only cots, sleeping in shifts, rather than a bed of their own. Submarine living. If your only talent is UX design, you had best hope that you can bend it to overhauling the control interface for some kind of harvester, wherein the panel will be staffed by someone who does not know how to read in a now-common hurricane downpour. If you are selected to reproduce, it will be only on the basis of genetic fitness to produce small individuals who probably don't need a lot of calories, in addition to being very healthy -- that almost goes without saying. And there will be no "inner party" having a grand time -- we simply wouldn't be able to sustain it.

In short, we had a pretty good time, but we did it for so long that now we're on lifeboat ethics that are completely at odds with the kind of liberties that we're used to and revolted over in the past. China's one child per couple will look like a pipe dream. Think "the Mona Lisa burned to heat this evening's soup" levels of subsistence after vast swaths of the populace were quietly euthanized. That might be our "soft landing." In the 1950s, we might have avoided gigadeaths. The hard landing looks like your basic Road Warrior cosplay, with some desperate nukes thrown around, a few biological agents escaping, and so forth on top of freshwater scarcity and so on.

At this point, I can only consider myself fortunate to be too old to have to witness it. I haven't reproduced and I have been ringing this particular bell since the day I apprehended our situation, but like most bad news, nobody wants to hear it, and especially if it goes against our basic instincts and philosophies.

If we do not control our populace, Nature will do it for us, and we are aware of Nature's methods. We have been for centuries. We willfully elected not to look at the difficult problem and have done so for generations. Let the good times roll, until we hit the brick wall. Then the Horsemen will ride.