We need to be really careful that in our haste to make progress in environmental protection and gender equality, we don't find ourselves heading down the dark path towards eugenics or self-extinction.
Or to not have children that you don't want, which is what the discussion is about.
We don't avoid killing ourselves or others because of its effects on the environment, which are great. We avoid killing ourselves and others due to other considerations. I bet you can name some so I don't have to.
That may well be true for most people. Luckily the environment isn't the only factor in ethical considerations.