Their point was that -- since there are a finite number of atoms in the universe-- it is a given that there exists some upper-bound on growth.
They are intentionally calling attention to that absurd extreme as a rhetoric device, not out of a belief that that's when we'll hit the wall. (It's a safe bet they believe will hit the wall much much much sooner.)
They are intentionally calling attention to that absurd extreme as a rhetoric device, not out of a belief that that's when we'll hit the wall. (It's a safe bet they believe will hit the wall much much much sooner.)