The world’s population reached 8bn people on Tuesday and will hit 9bn in 15 years as it experiences an unprecedented surge in the number of older people, according to the latest UN data. The global fertility rate has more than halved since the 1950s to 2.3 births per woman. With mortality also falling, the number of people aged 65 and over is expected to rise from 783mn in 2022 to 1bn by 2030 and reach 1.4bn by 2043, the UN population data revealed.