It's hard to see why "economic growth involves doing more with less" would work on a small timescale but not a big one. Indeed the main point of the article is

It's hard to see why "economic growth involves doing more with less" would work on a small timescale but not a big one. Indeed the main point of the article is that if you wait long enough, this will kick in, but that in the short run we have a problem. The same holds for population growth. As countries get richer the birth rate reduces. So there's very little chance that we'll stay on the current 1.1% curve, any more than we stayed on the analogous curve defined in 1950.