According to the report, by 2050 people aged 65 and over will make up 15.6 per cent of the global population, more than double young children, who will make up 7.2 per cent.
“These two age groups will then continue to grow in opposite directions,” the report notes. “This unique demographic phenomenon of the crossing is unprecedented.”
A commonly used indicator for the speed of population ageing is the number of years it takes for the older population to double from seven per cent to 14 per cent, and again from 14 per cent to 21 per cent.
In Australia, it took 73 years for the “doubling” to occur in 2014. The “tripling” will only take another 26 years, occurring in 2037, according to the US Census Bureau report.
While Europe will remain the oldest region through to 2050, the report notes that the size of Asia’s population and the speed of ageing means the total size of its older population will dwarf other regions.