Thresholds of temperature change for mass extinctions

Climate change is a critical factor affecting biodiversity, but the quantitative relationship between temperature change and extinction is unclear. The authors analyze magnitudes and rates of temperature change and extinction rates of marine fossils over the past 450 million years. Both the rate and magnitude of temperature change are significantly positively correlated with the extinction rate of marine animals. Major mass extinctions in the Phanerozoic can be linked to thresholds in climate change (warming or cooling) with magnitudes greater than 5.2 °C and rates greater than 10 °C per million years. These significant relationships persist when excluding the five largest mass extinctions. The study predicts that a temperature increase of 5.2 °C above the pre-industrial level at present rates of increase would likely result in a mass extinction comparable to major Phanerozoic events, even without other anthropogenic impacts.