The Last "Snowball" Ice Age

Scientists studied this area near Adelaide in South Australia to look for evidence of abrupt climate change. Researchers have discovered that an abrupt climate shift 635 million years ago may have been caused by an abrupt release of methane, a powerful greenhouse gas, escaping from ice sheets that extended to Earth's low latitudes. The researchers believe that the methane was released gradually at first and then very quickly as methane clathrates—methane ice that condenses beneath ice sheets or in the deep ocean—converted back into gas. The shift triggered events that resulted in global warming and an ending of the last "snowball" ice age.

Credit: Martin Kennedy/UCR