Greater temperature changes linked to worse extinction events

In a recent study from Tohoku University, Professor Kunio Kaiho has identified a disturbing link between climate shifts and mass extinction events. According to the research, the severity of an extinction event is directly correlated with the extent of the global temperature change. 

“Major mass extinctions in the Phanerozoic Eon occurred during abrupt global climate changes accompanied by environmental destruction driven by large volcanic eruptions and projectile impacts. Relationships between land temperature anomalies and terrestrial animal extinctions, as well as the difference in response between marine and terrestrial animals to abrupt climate changes in the Phanerozoic, have not been quantitatively evaluated,” wrote Professor Kaiho.

“My analyses show that the magnitude of major extinctions in marine invertebrates and that of terrestrial tetrapods correlate well with the coincidental anomaly of global and habitat surface temperatures during biotic crises, respectively, regardless of the difference between warming and cooling.”

Throughout the Phanerozoic Eon, which covers 539 million years to the present, there have been five major mass extinction events. The loss of species during these events corresponded with global cooling or warming of greater than seven degrees Celsius, according to the study. 

“These findings indicate that the bigger the shifts in climate, the larger the mass extinction,” said Professor Kaiho. “They also tell us that any prospective extinction related to human activity will not be of the same proportions when the extinction magnitude changes in conjunction with global surface temperature anomaly.”

“Although predicting the extent of future extinctions is difficult because causes will differ from preceding ones, there is sufficient evidence to suggest that any forthcoming extinction will not reach past magnitudes if global surface temperature anomalies and other environmental anomalies correspondingly change.”

Professor Kaiho also found that animals on land have a lower tolerance for global warming events compared to marine animals. On the other hand, marine animals have a lower tolerance for temperature changes in their habitats. 

According to Professor Kaiho, the results suggest that climate change and related or coincidental environmental destruction are the main causes of mass extinctions on land and in the sea.

The study is published in the journal Biogeosciences.

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By Chrissy Sexton, Earth.com Staff Writer