I wouldn't quite call world population growth a non-problem, considering it is already a problem. The future predictions may well turn out correct, and have some solid reasoning behind them, but the numbers still look fairly crude to me. Plots of historic growth rates are bouncing up and down, while the prediction is they will suddenly turn a corner tomorrow and drop monotonically to zero and all will be peachy. How often has that happened? Considering the current record-breaking population numbers, the ultimate answer is it has never happened, at least not permanently. There's a lot of risk in betting on things to just work themselves out. Development can actually work against us in a sense, as new food production technology and cures allow faster-than-ever growth in new regions and populations.