Thirty-nine years ago, on this day, August 21st, 1986,
On 21 August 1986, a limnic eruption at Lake Nyos in northwestern Cameroon killed 1,746 people and 3,500 livestock.[1]
The eruption triggered the sudden release of about 100,000–300,000 tons of carbon dioxide (CO2).[2][3] The gas cloud initially rose at nearly 100 kilometres per hour (62 mph; 28 m/s) and then, being heavier than air, descended onto nearby villages, suffocating people and livestock within 25 kilometres (16 mi) of the lake.[4][5]
A degassing system has since been installed at the lake, with the aim of reducing the concentration of CO2 in the waters and therefore the risk of further eruptions. Along with the Lake Monoun disaster two years earlier, it is one of only two recorded limnic eruptions in history
The amount of carbon dioxide in the air was 347ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was carbon dioxide was not something you read a lot about, back in the day.
What I think we can learn from this – carbon dioxide is not just “plant food”, as the denialists would have it.
What happened next – lots of monitoring work to make sure it couldn’t happen again.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Also on this day:
August 21, 1961 – The UN holds a “new sources of energy” conference.
August 21, 1972 – Nature editor John Maddox says C02-temperature fear “found wanting”
August 21, 2004 – The Australian reports on Howard cabinet split over ETS – All Our Yesterdays