By 2030, according to the population division, 97 countries in the world will be experiencing fertility below replacement level, or less than two children per woman.
Next year the working-age populations of the major economies will decline for the first time since 1950, and this includes Russia and China. Meanwhile, the major economies’ share of people 65 and older will soar.
The challenges of the 21st century, rather than stemming from overpopulation, appear to arise from falling fertility rates and larger aging cohorts with comparatively fewer from younger cohorts to support them.
Longer lives and falling fertility rates brings rapid global aging. By 2050, all major areas of the world except Africa will have nearly a quarter or more of their populations aged 60 or over.