Generations ago I would have agreed. Several generations of inaction have resulted in needing a less-than-two child rate. Before the Haber-Bosch process, human

Generations ago I would have agreed. Several generations of inaction have resulted in needing a less-than-two child rate. Before the Haber-Bosch process, humans numbered about 2 billion. That process requires fossil fuels. With some efficiency gains we can probably double that number, but along with many other triangulation points, it seems only a substantially smaller number than today's would allow sustainable human society. We can get there by lowering the birth rate or nature can do it for us, which would likely lower it well beyond.