I remember reading "The Population Bomb" as a child in the early 1970s. My mother was always the alarmist type and so had plenty of "gloom and doom" books on the shelves. Depressed the hell out of me though as I was naive enough back then to take it all serously.
The book gave a great accelerative kick to the birth control and ZPG movements, which were already well underway and funded by many governments, including ours.
Western countries took these policy suggestions to heart, with family sizes falling to close to or below the replacement rate. Of course, the third-world countries paid no attention.
Then, the switcheroo. When the first-world countries realized that their populations weren't growing fast enough to sustain the debt load that were the result of their deficit spending policies, their governments started saying "we've got to import more workers to replace the ones that we've lost!"
Guess where they started getting the replacement workers from?
Many here won’t like this, but I foresee that eventually solar and other power sources combined with domicile battery storage will be normal. There will then be extra power available that can be used for desalinization, vastly reducing the worldwide water shortage and turning desserts into highly productive farmland.
This assumes we are delivered from hell-bent depopulation overlords.
I also remember reading "The Population Bomb" in the early 1970s. My girlfriend's sister declared that no one should birth a baby in such a world. I married my girlfriend and we had our first baby in the late 1970s, and more later. Her sister eventually had a child in the early 1990s as a 40-year-old; I guess she finally gave up on the doom and gloom predictions.