Great Smog of London (1952)
A five-day smog from coal smoke settled over London under still, cold air. Visibility fell to a few metres. Contemporary estimates linked thousands of deaths to the event.
Public alarm forced air pollution onto the national agenda for the first time.
Britain passed the Clean Air Act in 1956, restricting coal burning and creating smoke-control zones.
It shows the same mechanism CAMS tracks today: winter weather trapping pollution near the ground turns steady emissions into a deadly spike.
