The population of the planet is increasing exponentially, and sooner rather than later that means it will be larger than the planet can support. If population growth is not reduced and, ultimately, stopped, people will be starving to death by the billion. Those that don't die in the inevitable wars for resources, anyway. OK, that makes it a self-solving problem, but personally I'd rather see it done by simple persuasion and improvement in economic conditions that make 'breeding as a pension policy' a historical relic. Agreed his 1977 suggestions seem somewhat extreme, though! Whether they will stay that way if the problem is ignored for another 50 years is a different question, sadly.