The World Might Run Out of People

I stopped reading after...

“In roughly three decades, the global population will begin to decline,” they write. “Once that decline begins, it will never end."

..obviously this is hyperbole to sell a book which has to be dramatic to get attention. Nobody knows for sure what the population will peak at and how far it might fall again. The world has never been in this situation before and so everything is currently a guess.

Or, through selection, a type of people or culture will arise that remains fertile even in the modern world. I think there's some precedent to this in nature...