The idea is complete nonsense. Even with absolute worst case climate change scenarios, the average person will have a quality of life vastly above basically anyone in the past. Especially during the Middle Ages when plague was killing people in the street. Yet those people still had families and children.

This is a cultural phenomenon, not a rational one, and has more to do with the West’s lack of a coherent worldview in our post-Christian age. It’s a problem of nihilism.

The “interesting” part is that this, like all scenarios, has evolutionary consequences. People that don’t buy into the climate change = I don’t want kids narrative will out-reproduce and out last those that do. The future isn’t a small society of rationalist childfree vegans, it’s comprised of people that have a lot of kids.