Large parts of humanity have always had a problem getting water or food and it had nothing to do with global warming, rather politics, governance, and culture. These will always be a bigger problem.
Yes. But not relevant. One has to remove such constants in order to see what's new.
So, while "Large parts of humanity have always had a problem getting water or food and it had nothing to do with global warming", now it also HAS to do with global warming.
Also note that regardless of what you think in general about the impact the growing number of humans has on the economic growth, it's hardly debatable that if Richard Stallman specifically had decided to have children, his children would have very likely contributed much more than an average human, just like RMS himself has.
So in reality his decision was exactly counterproductive providing parts of humanity with water or food.
To all the parents out there (I am not one): Thank you. You don't know me, but your decision to have a child is as good as if you donated maybe $1e-4 to my 401(k). And everyone else's. If you live in the US, more. If you are a very smart and hard working person, even more. By caring for your own child, you're also feeding some hungry child in Africa 25 years from now. Richard Stallman should be grateful to you.