Ehrlich's "The Population Bomb" from the 70s has given this sort of thing a bad name. The problem is that there is absolutely zero doubt that the fundamentals

Ehrlich's "The Population Bomb" from the 70s has given this sort of thing a bad name. The problem is that there is absolutely zero doubt that the fundamentals are correct: there are limits to the population the earth can support and our population is still growing at a crazy rate (even if the growth is decelerating a bit). The dilemma is that we don't know what the limits are. Every previous attempt to calculate or predict them has failed in significant ways. So while it seems right to raise the alarm, it also seems hard to take any actual prediction seriously. I think we're likely better off with approaches that don't stress the (potential) crash. Emphasize that we have plenty of people already for us all to lead a wonderful life, and maybe we could just get to steady state because that will bring us all lots of benefits, whether the crash is 25 or 25,000 years away.