The Earth has a long history of mass extinction events, but geologist Paul Wignall suggests they have decreased due to fragmentation of the continents and megavolcansim weathering.
Wignall’s theory suggests that as continents fragmented they were better able to remove CO2 from the atmosphere, decreasing the likelihood of a future extinction event (asteroids and manmade global warming notwithstanding.)
My megavolcansim weathering illustration shows how these smaller continents receive CO2 that has been dissolved in rain water, which forms carbonic acid and chemically reacts with silicate rocks. This “weathering” releases soluble calcium and bicarbonate ions into streams, which carries them to the sea. In the ocean, shellfish and some corals take up the calcium and bicarbonate ions, combine them into calcium carbonate, and deposit it in their shells and skeletons. Each year about 0.3 gigaton of CO2 is removed from the atmosphere through this process. Thanks, shellfish!