All the people: what happens if humanity’s ranks start to shrink?

The battle to feed humanity has been lost, Paul Ehrlich warned in his influential 1968 treatise, The Population Bomb. The world’s population was growing faster than the Earth could sustain, he predicted, and catastrophe loomed. “In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.” That doomsday message turned the entomologist into a celebrity and galvanised population…