I'm really struggling how this is a bad thing to be honest. The planet is already overpopulated, and each new person introduces a huge carbon footprint.
For all know biological species the size of population is a primary indication of health and well-being. Shrinking population indicates inability to adapt or some kind of malaise.
Personally, I don't believe there is such thing as overpopulation. There is ineffective utilization of resources and poor management which can be viewed as inability to adapt. Ancient cities couldn't grow beyond 100K population because they didn't have sewers. Once sewers became widespread, major cities hit 1 mln in just a few centuries. I believe the Earth can host many more people than it does now if resources and space are utilized efficiently and human morale is high.
That's a good point. Of course there is a physical limit of placing many humans in a limited space (if we assume that there will be no low orbit habitats which may not be the case). However, it would rather be economical reasons to leave overpopulated areas (e.g. move to LEO/Mars/Moon) rather than fertility related. For instance, people may leave New York because it feels too crammed, but nobody in their right mind would say "it would be great if fertility of New Yorkers went down as low as possible".
So my point stands -- the problem of overpopulation is not real as long as humans can adapt technologically, environmentally, and socially. The Earth is a limited space only as long as humans don't have the technology to expand habitable space above (and below) the surface. And above the surface only the sky is the limit. Literally :)
Space colonization cannot and will never relieve overpopulation, and it's time for that notion to die. The USA alone sees roughly 4 million births per year. That's 11 _thousand_ births per day. It is completely delusional to expect our species to lift enough people out of our gravity well to put a dent in population growth.
This makes sense. I'm all in for having fewer people, but if we could reach the same welfare with 1% of resources we use now, we could easily 100x the human population. Even if the planet is finite, there is loads of room for more people without destroying the rest of the planet. The problem right now is that we don't have the technology and the resources are finite. It also looks like we may be paying for the over consumption soon in the form of climate change... Without a major scientific breakthroughs there is no room for more people really.
What we can do to reduce population? Education. Worrying about poor people in poor countries having more babies? Educate them and help them to get a proper job - problem solved.
It could be a bad thing in the medium term if the number of older people requiring care overwhelms the ability of societies to provide (given fewer working age people contributing). In the longer term, yes, sustainable population certainly seems like a good thing. (Although one could make a utilitarian argument that as long as it _is_ sustainable, and assuming people's lives are generally good, you want as many people as possible.)
Exactly. Pension systems where generation i+1 pays for generation i are fundamentally broken. If the population size sinks, generation i+1 will pay more. If paying more and thus having less disposable income makes them defer having babies, you have your bad feedback loop right there.
A better and stable system is where generation i pays for generation i.
