450007 VO Phanerozoic Mass Extinctions (NPI) (2015S)

The Phanerozoic record of global physical perturbations and mass extinctions provides a key repository for understanding Earth’s integrated physical and ecosystemic responses to crises. Modern climate change and extinction, far from being unprecedented, can be viewed as just the most recent forays into an Earth perhaps unfamiliar in the present, but largely recognizable in the geological past. This course, therefore, explores these changes by a review of the physical and biotic conditions associated with the five great Phanerozoic mass extinction events. It culminates in the current biotic and climate crisis(es), posing the question of whether the biotic and climatic records of the past 125,000 years suggest that the Earth is currently undergoing a sixth mass extinction of the type previously seen on Earth; or whether this is unprecedented in Earth history.