According to UN projections published in 2024, the world's population should top out at roughly 10.3 billion in the mid-2080s, then edge down. The UN now puts the chance of a peak this century at about 80%, up from just 30% in its 2013 projections. The main reason: fertility is falling faster than expected in several very populous countries.
That's the estimate from a WHO-led study published in The Lancet in 2024, covering the half-century since the Expanded Programme on Immunization was launched in 1974. It works out to about six lives saved every minute, mostly infants. The measles vaccine alone accounts for around 60% of those lives.
According to the World Gold Council, about 216,000 tonnes of gold have been mined in all of human history. Because gold is so dense (19.3 tonnes per cubic metre), it would fit in a cube about 22 metres on each side, roughly the height of a seven-storey building. Strikingly, about two-thirds of it has been mined since 1950.