In 1986, a Cameroonian lake released a CO2 cloud that killed 1,746 people overnight
On the night of 21 August 1986, Lake Nyos in northwestern Cameroon released between 100,000 and 300,000 tons of carbon dioxide in a single outgassing event. The cloud rose at nearly 100 km/h, then sank — carbon dioxide is 50 percent more dense than air — and moved downvalley at 20 to 50 kilo…
