Past massive volcanic eruptions linked to abrupt Southern hemisphere climate change

Some 17,700 years ago, a series of volcanic eruptions occurred in Antarctica. They lasted for 192 years, and coïncided with a dramatic change in climate: winds, sea ice, ocean circulation… everything was affected on and around the continent. The volcanoes emitted loads of halogen gas, which may even have been responsible for the creation of an ozone hole, like we experience today. The effects of these massive and long-lasting eruptions extended to as far as South America.

https://knowridge.com/2017/09/massive-antarctic-volcanic-eruptions-linked-to-abrupt-southern-hemisphere-climate-change/