Na, I think it is downvoted because it is pretty neo-liberal, to assume that population control is the solution, because it implicitly neglects that most emissions are caused by the richest people. Reducing those rich people would well be a fair point, though.
Your point logically implies that you are against increasing life conditions of the people that are born poor in those countries with high birth rates.
Also, rich countries already have birth rates below the replacement rate (as you can attest if you consult the information that was provided in my original answer).
