By researcher Vaclav Smil's calculations, China used about 6.6 billion tonnes of cement between 2011 and 2013, compared with around 4.5 billion tonnes for the United States over the entire 20th century. It illustrates the unprecedented speed of modern urbanisation: hundreds of millions of people moving to cities within a few decades, with roads, towers and networks to build.
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.