A supervolcano eruption, specifically the Toba supervolcano, is reported to have depleted the earth's ozone layer around 74,000 years ago. This event may have caused severe tropical stratospheric ozone depletion, potentially exposing early humans to intense sunburns and possibly even leading to a population bottleneck. The eruption's effects are being studied for insights into human survival and the impact of large volcanic events on the environment.