The Panama Canal doesn't run on seawater: its locks lift ships about 26 metres up to Gatún Lake, a man-made lake fed by rainfall. Every transit through the original locks sends some 200 million litres of fresh water flowing out to the ocean. The newer locks, opened in 2016, recycle part of it. During the 2023 drought, the canal authority had to cap the number of daily crossings.
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.