It seems like you may be misinterpreting what "family planning" means. "Family planning", as it's commonly understood, is an umbrella term for how normal, ever

It seems like you may be misinterpreting what "family planning" means. "Family planning", as it's commonly understood, is an umbrella term for how normal, everyday people avoid having children when they don't want to have them. When toxik responded to your question "Who will decide who lives? Or who has kids and a family?" with "Probably just family planning. Nobody needs to die to save the earth", they are suggesting that humans will continue to practice (as we have for millennia) techniques that reduce the number of unplanned children we have.