Extinction is inevitable. Expected. Almost all (99%) species that have ever existed have died out. Those disappearances have largely occurred at consistent background rates. But in the context of mass extinctions, ecosystems are placed under immense pressure, at above-average speeds. Here, the language changes from the commonplace to the exceptional.
The most recent of these events occurred at the end of the Cretaceous period, 66 million years ago, following an asteroid collision off the shore of Mexico. And 252 million years ago, at the Permian-Triassic boundary, Earth experienced its most severe loss of animal species to date when mass volcanisms pumped carbon into the air, suffocating life and acidifying oceans, killing off up to 96% of all marine species.
