Ancient supervolcano's eruption caused severe winters

Previous studies have suggested that Indonesia's Toba supervolcano, when it erupted about 74,000 years ago, triggered a 1,000-year episode of ice sheet advance, and also may have produced a short-lived 'volcanic winter,' which drastically reduced the human population at the time. Previous climate model simulations of the eruption have been unable to produce the glaciation, and there are no climate observations to support the volcanic winter.