You're still talking about an unavoidable consequence, do you really think if people are told not to have kids they won't?

Even in China where you could be severely punished for having more than one child, people were having many children and in most cases killing their girls to have a boy because of their desire for their family to succeed. So, I don't know what you're arguing.

Saying "not having kids is best for the environment" is one thing, suggesting we actually do that is an entirely different book of frogs... no one will do that. However, people can easily and do change their diets and actually bother with some real change, not just arguing with strangers on the internet to avoid having to do anything.