The Kalkarindji volcanic region in Australia erupted a long time ago and released a lot of CO2 into the air. Some scientists think this may have caused big changes in the environment during the Cambrian period, like mass extinctions. However, there are still uncertainties about whether the volcanic eruptions directly caused these extinctions. More research is needed to understand the exact relationship between the volcanic activity and the environmental changes that happened at the beginning of the Phanerozoic era.