The Laki fissure eruption in Iceland (June 1783–February 1784) released approximately 120 million tons of sulfur dioxide, which formed a toxic, sulfuric-smelling "dry fog" (known in Sweden as sol-röken) that drifted across Europe via the jet stream.  This haze, visible as far south as Italy, caused widespread respiratory distress, headaches, and eye irritation among European populations, while also damaging crops through acid rain.

While the immediate impact in Iceland was catastrophic—killing over 9,000 people (nearly a quarter of the population) and 60% of livestock due to fluorine poisoning and famine—the European mortality toll is estimated to be in the thousands.  Historical figures like Benjamin Franklin and French naturalist Mourgue de Montredon were among the first to correctly link this unusual atmospheric phenomenon to the Icelandic volcanic activity, despite contemporaries often attributing the "blood red" sunsets and fog to other causes.

 (It is possible that major earth changes somehow coinicide with major social upheavals as we are experiencing today)