Things don't happen in a vacuum and trying to extrapolate current trends 100+ years into the future is a fool's errand. A couple decades ago everyone was worried about the opposite problem. Neither of us has any idea what the new worry will be in a few more decades.
The earth currently has billions more people than are necessary to keep humanity going; there's plenty of slack in the current system. Yes societies will have to evolve if birthrates stay low for a while, but they always have to evolve and if populations ever did drop precipitously low people already know how to make more babies.
The earth currently has billions more people than are necessary to keep humanity going; there's plenty of slack in the current system. Yes societies will have to evolve if birthrates stay low for a while, but they always have to evolve and if populations ever did drop precipitously low people already know how to make more babies.