It was during the American Revolution that one of the world’s great climatic disasters occurred. It happened at Lakagigar—“The Craters of Laki”—where a volcanic fissure opened up during an eight-month period between 1783 and 1784 near the village of Kirkjubæjarklaustur in South Iceland. Before it had finished, it had pumped 3.4 cubic miles (14 cubic km) of basaltic lava, hydrofluoric acid, and sulfur dioxide that killed 50% of Iceland’s livestock and, after the ensuing famine, 25% of Iceland’s population.
The effluents from the eruption caused a drop in temperature that caused massive crop failures in Europe and a drought in India. According to Wikipedia, in the end as many as six million deaths were attributed the after-effects of Laki. That would make it the most deadly eruption in modern times.
Today, the moss-covered mountains are crowded with European tourists visiting Vatnajökull National Park, of which Laki is now a part. In her column in the Iceland Review, writer Zoë Robert complains of the tourists’ heedlessness:
While chatting to the park ranger the next day, I expressed my shock at the recent incident at Þingvellir National Park where several campers ripped up large amounts of moss in order to insulate their tents, causing many open scars in the land. While the ranger too indicated her dissatisfaction, she pointed out that large moss areas, like those which exist in Iceland, are rare in other countries and that some people may not realize their true value. This I understand, but I still find it difficult to accept that people can willingly uproot large areas of vegetation, especially in or near a national park, and think that is admissible.