Tucker Carlson, the most popular host on US cable TV, has been sacked by Fox News. In one of his final interviews he spoke with Elon Musk about declining global birth rates. The tech entrepreneur believes that birth control and abortion could spell the end of modern civilisation as we know it.

There is no guarantee that we will not go the way of the Egyptians, Sumerians and Romans, Musk said. “There’s sort of a life cycle arc to civilizations, just as there are to individual humans.” He recalled that Japan had twice as many deaths last year as births.

“In the past, we could rely upon simple limbic system rewards in order to procreate,” Musk said. “But once you have birth control and abortions and whatnot, now you can still satisfy the limbic instinct, but not procreate. So we haven’t yet evolved to deal with that because this is all fairly recent, you know, the last 50 years or so, for birth control.”

Civilisation is built on population.

“If we don’t make enough people to at least sustain our numbers, perhaps increase a little bit, then civilization is going to crumble,” he said. “The old question of like, ‘will civilization end with a bang or a whimper?’ Well, it’s currently trying to end with a whimper in adult diapers.”

“That’s depressing as hell,” said Musk ruefully.