Five rules for an ageing world

THERE are two kinds of people in the world: Those who believe the defining challenge of the 21st century will be climate change, and those who know that it will be the birth dearth, the population bust, the old age of the world.

That kind of column opener is a hostage to fortune. If I’m wrong, it might be quoted grimly or mockingly in future histories written with New York underwater and Texas uninhabitable.

But it’s important for the weird people more obsessed with demography than climate to keep hammering away, because whatever the true balance of risk between the two, the relative balance is changing. Over the past 15 years, some of the worst-case scenarios for climate change have become less likely than before. At the same time, various forces, the Covid crisis especially, have pushed birth rates lower faster, bringing the old-age era forward rapidly.