 Although the eruption was about twice size as the 1991 eruption of Mount Pinatubo, it contained considerably more sulfur, potentially rivalling the climatologically very significant 1815 eruption of Mount Tambora in terms of amount of sulfur introduced into the atmosphere.Evidence exists that an eruption of this magnitude and sulfur content occurring during deglaciation could trigger a long-term positive feedback involving sea ice and oceanic circulation, resulting in a cascade of climate shifts across the North Atlantic and the globe.Further support for this hypothesis appears as a large volcanogenic sulfur spike within Greenland ice, coincident with both the date of the Laacher See eruption and the beginning of cooling into the Younger Dryas as recorded in Greenland.