Earlier quoted context omitted.
that's funny because many cities have a replacement rate less than 2, not counting immigration. And even with population growth at e^n, the constants matter in the analysis. l^3 growth may be enough until humans reach space faring.
Space only grows as l^3 and the speed of light. Any species that does not limit the number of surviving children per parent to two will run out of space no matter what they do.
the point is that human's growth is slowing, and the fact that space can open up means that as long as humanity reaches being a space faring species, it won't really be a problem.