World population is going to be a problem, but it's not a realistic show stopper.
Riiiight. That attitude is partly the reason we're facing the issues we're now facing.
I'll remind you of that quote when the wars over food & water start. When countries that can actually grow surplus food start selling it to the buyer with the deepest pockets, when riots start because people can't get enough food. Water we more-or-less should be OK with, as long as we provide enough desalination plants, but - ah, of course, they take a lot of energy to run, so it will depend on whether the country has enough power / resources to run them.
Like any life form, its quite possible for the life form to end up sucking all the resources from the planet and then demand outstrips supply.
Of course, it will be the poor countries that suffer first, then the most densely populated ones, the ones that can't feed their own populations.
It may not be an issue right now, but I'm sure as hell expecting it to be an issue for our Children. Lets face it, by the time my daughter is 20, it'll be 2031 and the population is expected to be 8.3 billion.
That's more demand for food, water, clothing, heat, housing, fuel, oil etc..
It can't keep going on, something, somewhere and sometime will give.....