They could off themselves as well. That would help too. 4 billions of years of evolution end with me! What an absurd take. I'd understand one child, fewer than desired, etc.. but no children as a conscious effort to help the climate is something I don't buy that ever happened. Other reasons are at play for that. Nothing to do with the climate.
Until recently I was strictly against having kids because of the world climate, both weather and political. But then my partner wanted them and I couldn't stand the notion of losing her, so I was able to compromise on my ideals.
But yeah without her, definitely.
but no children as a conscious effort to help the climate is something I don't buy that ever happened
That's not what I said. People are choosing not to have children for lots of reasons. One of the benefits is that they end up having much less impact on the climate; that's not saying it's the reason they're doing it.