Lakagígar

Part of the northern Laki crater row with Síðujökull (part of Vatnajökull) in the background.

The Laki fissure eruption of 1783/84 was one of the greatest natural disasters of the last 1000 years. A total of 14,7 km³ of lava flowed from 130 vents, eventually covering 600km². 122 million tonnes of SO² and 15 million tonnes of fluorine were emitted. In Iceland 80% of sheep and over 50% of other livestock died of fluorine poisoning, more than 20% of Icelanders died of starvation.
The poisonous cloud covered much of Europe as a dry fog, leading to high excess mortality, crop failures and famine. Temperatures dropped by an average of 1,3°C for 2-3 years, causing an extremely cold winter and enormous flooding after snow melt in spring.

www.economist.com/christmas-specials/2007/12/19/the-summer-of-acid-rain

whc.unesco.org/en/list/1604

de.wikipedia.org/wiki/Laki-Krater