That being said, the lack of population growth we're seeing likely represent a crisis of some kind across the world. Otherwise if it's benign, it just means that people just don't wanna start families.
Little girls raised by mothers who only have 1 child don't grow up thinking that they want five children. Little girls who grow up being taught by childless teachers, excited and inspired by childless role models in the entertainment industry don't think they want four children. When they're bombarded with propaganda about how "adoption is just as good", they tend to believe that. And so on.
These things don't change just because population is shrinking. I'm not a conspiracy theorist, I don't believe these things to be deliberate. But I do recognize them for what they are.
> There is no reason to expect that the population will die out in a few century, only that we are in a currently bad situation.
There actually is. People like yourself tend to look at the "population". "Gee, there's 7.2 billion sixty year olds! We'll never go extinct." But it's really the one small demographic slice that is shrinking all the time, even while population grows... the demographic still young enough to make more people.
Your claim is that this trend doesn't just stay the same, that it might reverse. But it's so much worse than it merely not reversing... the trend becomes more extreme. As fertility falls, there are far fewer examples of high fertility for children to grow up around and be normalized to. They lower their own fertility in adulthood in response. Fertility decline is set to accelerate, not slow.
Your claim is that this trend doesn't just stay the same, that it might reverse. But it's so much worse than it merely not reversing... the trend becomes more extreme. As fertility falls, there are far fewer examples of high fertility for children to grow up around and be normalized to. They lower their own fertility in adulthood in response. Fertility decline is set to accelerate, not slow.
Big claim you're making. Populations are not homogeneous.
The relatively few families that have five children, and assuming that the values of having a large family can be passed to offspring, they will continue to have large families.
In a couple generations these people will become the majority of the population and the birth rate goes back up again.
If somehow I were wrong on this, it still wouldn't fix the problem. Technological civilization can't be put on pause for 150 years while they manage to get population back up to a level where it can carry that burden. How many of those children six generations in are likely to make it out of childhood without modern medicine?
It would be one thing to hold out hope for change if attitudes towards this issue with different... but in a world that shrugs and says "oh, things might be different in 50 years" when no one even wants things to be different in 50 years and aren't acting in ways that would cause things to be different in 50 years, then I feel pretty confident telling you that you're just plain wrong.
I don't think you understand the math of this. It's not that anyone wants a higher population, it's that the spectrum is a little screwed up. There's this line in the middle (fertility rate 2.1), and anything to the right of that is "population spirals out of control". Then everything to the left of it is "human extinction in just a few centuries".
We're currently on the "human extinction in a few centuries". And all the arguments that we're not are positively stupid. People seem to think that we're like moose on some island, that "population bounces back" (it does for animals, because their fertility rate never goes below replacement, so when population pressures subside, their populations recover). Every time you ask "what's the case for higher population", you're actually helping to murder our entire species.
If you were rational, you'd be pushing the idea that we need that 2.1 fertility rate, the one that doesn't result in higher population, and doesn't result in human extinction.