On August 21, 1986, a catastrophic “Limnic Eruption” occurred at Lake Nyos in Cameroon. The lake, which sits inside a volcanic crater, had been quietly accumulating massive amounts of carbon dioxide at the bottom for centuries. That night, something triggered the gas to release—likely a landslide. The lake suddenly “burped,” expelling a massive cloud of CO2 estimated at 1.6 million tons. Being heavier than air, the gas cloud hugged the ground and flowed down the valley at 60 mph, displacing all