Climate scientist Kunio Kaiho from the University of Tohoku in Japan said that the sixth mass extinction in the history of the Earth cannot be compared with the previous ones. In any case, it will not be so for the next centuries, reports science alert.
Over the past 540 million years, our planet has repeatedly lost most of its species diversity in a relatively short period of time. Such events are called mass extinctions and often follow global climate changes, whether it be cooling or warming.
In the course of the study, Kaiho attempted to quantify the relationship between the average temperature on Earth and the biodiversity of the planet. As a result, he found out that there is a linear relationship. The more temperature changes, the greater the change in biodiversity.
When it comes to global cooling, the greatest extinctions have occurred when temperatures dropped by about seven degrees Celsius. If we were talking about global warming, then the largest extinctions occurred when the temperature rose by nine degrees Celsius.
This is much higher than previous estimates, which suggest that a 5.2 degree Celsius rise in temperature will lead to mass extinction of marine life. According to current estimates, by the end of the century, the temperature on Earth could rise by 4.4 degrees Celsius.
“Global warming of 9°C is not expected in the Anthropocene until at least 2500 in the worst-case scenario,” Kaiho predicts.
At the same time, the scientist does not deny that the extinction of animals on land and in water is already happening, but notes that the pace and scale of this extinction cannot be compared with the previous ones.
But, nevertheless, not only an increase in temperature leads to extinction, but also the speed with which it occurs. The most massive extinction on Earth, which occurred 250 million years ago, led to the extinction of 95% of species and lasted more than 60 thousand years. But today, warming is happening much faster due to anthropogenic emissions.
It is likely that more species will disappear during the sixth extinction, not because the scale of warming is so great, but because the temperature is rising so quickly. Because of this, species do not have time to adapt.
“Predicting the magnitude of a future anthropogenic extinction using surface temperature alone is difficult because the causes of anthropogenic extinctions are different from the causes of mass extinctions in geologic time,” admits Kaihu.
Recall data from the European Copernicus satellite system showed that the past seven years have been the hottest on record. Last year, 2021, was the fifth hottest year on the list, with temperature records recorded in some regions.