We’re projected to stabilise off at about 10 billion I believe. Which while a huge number, is not unsustained exponential growth. As countries get richer and w

We’re projected to stabilise off at about 10 billion I believe. Which while a huge number, is not unsustained exponential growth. As countries get richer and women gain better access to education and improved rights, the countries seem to go through an inflection point where suddenly no one wants to have children and the birth rate falls below replacement (2.0, two children to replace two parents) For us as a species to survive we need to try and stabilise that at 2.0 + some small safety margin (to make up for infertility, people who really don’t want children, or physically can’t). While we’re bound to one planet (which it looks like is going to be for awhile, “sending people to Mars” is very different from “sizeable % of the total human population living on Mars”) it’s preferable for that stable population point to be as small as possible. 10 billion is a lot, but it looks stable at least. If we bring our replacement rate down more to peak the total population earlier, we have this weird problem where the replacement rate is well below 2.0, so no one is having children, and we suddenly have to convince people to start having more. It feels like everything else in life; the birthrate would keep yo-yo-ing above and below replacement rate, and we really don’t want it above while it’s so cramped here and we’re messing up fundamental environmental systems that we rely on. Like everything else these days it seems like it kind of comes back to “well, if you want to do something, first we’ve got to deal with climate instability”. /shrug