France heat wave sparks myth busting and AC origin reminder

On 25 June France recorded its hottest day ever, driving millions of people to seek air‑conditioners as temperatures surged. Online posts claimed the extreme heat was engineered through the release of aluminium in "chemtrails", alleging a targeted climate attack on the country. Climate scientists from the CNRS and Météo France rejected the theory, explaining that a heat dome forms when a high‑pressure anticyclone blocks air aloft, causing adiabatic compression and rapid warming—processes far larger than any contrail effect. They stressed that ordinary contrails consist only of water vapour and particles, not aluminium, and cannot generate such a dome. In the same context, a historical note clarified that modern air‑conditioning was invented in 1902 by American engineer Willis Carrier to control humidity in a Brooklyn printing plant, not for human comfort. Residential cooling only became widespread in the 1950s‑60s, and the first public comfort‑oriented installation was the Rivoli Theatre in New York in 1925. The piece juxtaposes the current heat‑wave crisis with the origin of the technology many now rely on for relief.