Way back in 1816, Europe and North America suffered heavy rains, odd-coloured snow, famines, fogs and bitter cold during the summer. It wasn't the apocalypse though — it was the result of a supervolcano eruption.
In fact, the effects of Mount Tambora in Indonesia were felt over 1600km away and endured for at least a year after it erupted. This video explains the very real and colossal consequences of a supervolcano — both near and far. [TED-Ed]