When it erupted about 74,000 years ago, Indonesia’s Toba supervolcano may have triggered a 1,000-year episode of ice sheet advance, and a short-lived “volcanic winter” that drastically reduced the human population at the time.
6 Jul 09 — Robock et al. conducted six climate model simulations that included vegetation death effects on radiation budgets, and stratospheric chemistry feedbacks that might affect the lifetime of the volcanic cloud. They used a wide variety of aerosol injection volumes from 33 to 900 times that of the 1991 Mount Pinatubo injection.
Although none of their models initiated glaciation, they did produce a decade of severe volcanic winter, “which would likely have had devastating consequences for humanity and global ecosystems, supporting the idea that the Toba eruption produced a genetic bottleneck in human evolution.”
If Robock et al. had included a huge simultaneous increase in underwater volcanism to their models, I think they would have found an increase in ocean evaporation leading to vastly increased precipitation, which would have produced their missing glaciation.
If a supervolcano should erupt today, I think we’d descend into an ice age within months, if not weeks. Literally billions of people would soon die of starvation.
See entire article:
Thanks to Jimmy Walter for this link