Q1.
Have you ever wondered how many people live in the world?
Answer
8.2 billion, in 2025 (Fig. 6.4 and Fig. 6.6). In 1950 the figure was 2.5 billion; the United Nations expects 9.7 billion by 2050 and a peak of about 10.3 billion in the mid-2080s.
Those 8.2 billion people are very unevenly spread (Fig. 6.6):
Asia: 4.8 billion → 4.8 ÷ 8.2 = about 59 per cent of humanity
Africa: 1.5 billion → 1.5 ÷ 8.2 = about 18 per cent
Europe: 744.3 million → about 9 per cent
Northern America: 387.5 million → about 5 per cent
Africa: 1.5 billion → 1.5 ÷ 8.2 = about 18 per cent
Europe: 744.3 million → about 9 per cent
Northern America: 387.5 million → about 5 per cent
India alone had about 144 crore people in 2024 (Fig. 6.3) — more than any other country since it passed China in 2023, and
144 ÷ 820 = 0.176 → roughly 17 per cent of everyone alive
Why the chapter opens with this question: it is deliberately a question whose answer is never one number. Knowing there are 8.2 billion people tells you nothing useful on its own. You also need to know how old they are, where they live, what work they do and how fast their numbers are changing — and that is exactly the set of questions demography exists to answer.