I find this argument extremely offensive. Do you think the life of a child born in a +3C USA is going to be worse than the life of an adult currently in say Bangladesh? If not, the implication is that it wasn’t “ethical” for the parents of living Bangladeshis to have had kids given how “hard” their lives are. That currently living Bangladeshis would’ve been better off never being born than suffer such a low standard of living.
Presumably, there is a standard of living where it becomes “ethical” to have children. Show me where in the happiness scale (from Norway at the top to Central African Republic at the bottom) that transition happens: https://news.gallup.com/opinion/gallup/206468/happiest-unhap.... Italy has a happiness rating a full point lower than the US. Was it “unethical” for the previous generation of Italians to birth the current generation of Italians into such a hard life? Or do we need to go further down the scale? About a point below Italy is Nigeria. Is that the transition point? Once you can expect your kids to have a quality of life better than that of Nigerians currently, it’s ethical to have kids?
I mean, if you feel you don't want to bring kids into this turbulent, uncertain world, by all means don't, but please also recognize that one of life's biggest purposes is to beget life and we will do nothing (and have never done anything) if we didn't reproduce