Final answer:
The main driving factors for each of the 5 major mass extinctions are major environmental catastrophes that caused significant changes in the Earth's climate and ecosystems.
Step-by-step explanation:
The main driving factors for each of the 5 major mass extinctions are major environmental catastrophes that caused significant changes in the Earth's climate and ecosystems. For example, the most famous mass extinction at the end of the Cretaceous period was caused by a meteorite impact that threw dust into the atmosphere, blocking sunlight and leading to food shortages. The Late Permian mass extinction, the most devastating of all, was likely caused by global warming and changes in ocean chemistry due to massive volcanic eruptions.