Scientists have discovered evidence pointing to a substantial link in geologic time between the size of mass extinctions and global temperature fluctuations.
This intriguing association indicates a more positive view of future extinction events.
High temperature, high risk of extinction
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Throughout the Phanerozoic Eon (539 million years to the present), abrupt climatic change, along with environmental degradation caused by huge volcanic eruptions and meteorites, has resulted in numerous mass extinctions.
There have been very few quantitative assessments of the association between land temperature anomalies and terrestrial animal extinctions so far.
Furthermore, the extinction rates of marine and terrestrial creatures have diverged, and this phenomenon is yet unknown.
Professor Emeritus Kunio Kaiho revealed that the extinction rates of marine invertebrates and terrestrial tetrapods were linked to variations in global and habitat surface temperatures, regardless of whether they were cooling or rising.
Loss of species during the 'big five' major extinctions was associated with a > 7°C global cooling and a > 7-9°C global warming for marine animals, and a > 7°C global cooling and a > 7°C global warming for land animals.
"These data suggest that the larger the climatic shifts, the greater the mass extinction," Kaiho added. "They also tell us that any future extinction caused by human activities would not have the same proportions when the size of the extinction changes in combination with a global surface temperature anomaly," as per ScienceDaily.
According to Kaiho, a 5.2°C temperature increase in average global temperature would result in a major extinction catastrophe equal to past ones.
However, according to the findings of this study, the temperature must rise by 9°C, which will not occur until 2500 in the worst-case scenario.
Though estimating the amount of future mass extinction events is difficult since reasons will differ from previous ones, Kaiho believes that if global surface temperature anomalies and other environmental abnormalities shift, any approaching extinction will not surpass prior magnitudes.
Kaiho also discovered that terrestrial tetrapods had a poorer tolerance for global warming events than marine organisms.
However, marine creatures were less tolerant of the same temperature variations than terrestrial animals.
This is due to the fact that the temperature anomaly on land is 2.2 times greater than the sea surface temperature. These occurrences are consistent with current extinction processes.
A new study warns that climate change might lead to the extinction of one-third of all animal and plant species by 2070.
Researchers looked at recent extinctions caused by climate change to anticipate how many species will be lost in the next 50 years.
Scientists from the University of Arizona examined data from 538 species at 581 locations throughout the world, focusing on plant and animal species that were observed at the same locations at least 10 years apart.
"By analyzing the change in 19 climatic variables at each site, we were able to determine which variables drive local extinctions and how much change a population can tolerate before going extinct," said Cristian Román-Palacios of the University of Arizona's department of ecology and evolutionary biology in a statement, as per USA Today.
According to a United Nations assessment issued in May, up to 1 million species are at risk of extinction due to human activity. Many researchers believe a "mass extinction event" is already beginning, the sixth in the last half-billion years.
