I assume that if we could just get our exploding population under control, we could stay here and enjoy living on Earth.,(reply>), Not if we get clobbered by a meteor, or smoked by a sun burp, or dusted by a supervolcano, or decimated by a much worse pandemic, sickened by a nuclear exchange, etc. etc. etc.  There have been quite a few mass extinctions, it's wise to expand.