"Future survival of our own species"? Nah. The last human being will eat the last cockroach. We have made technology to adapt to living on the moon. We might make things painful for humanity in general, might even break civilization (although I think that's unlikely). But survival of the species? We haven't yet invented technology that can wipe out humans.
As for our "evil", "obscenely inflated population levels"... well, what do you think we should do about it? Because the only "solution" I can see to this thing that horrifies you is what the Nazis called a Final Solution. The global population is what it is, whether you like it or not. If you had Thanos' infinity glove, would you use it? Would you use it, knowing you're just knocking the population back to 1965 levels?