If fossil fuel emissions continue at this rate, the oceans could experience a new mass extinction by the year 2300, concludes a new study by researchers at the University of Washington and Princeton University (USA). The positive? That we still have time to avoid it.
Another ‘Great Death’ could be just around the corner
Scientists have modeled the extinction risks of future marine life in all the world’s oceans under different climate scenarios. They used ecophysiological models to weigh physical species limits against projected sea temperatures and depleting oxygen levels, a task that was particularly challenging given the lack of previous work in the area. What they saw in the results does not bode well for us.
Alarming results
If emissions are not reduced, the loss of marine species from global warming and oxygen depletion could resemble the ‘Great Dying’, the deadliest extinction event on Earth. It was the Permian-Triassic extinction event, approximately 250 million years ago. Informally known as the ‘Great Dying’, it triggered the death of 95% of all marine life. According to experts, the extinction predicted for the future (by 2300) would also be comparable to other major extinction events in Earth’s history, such as the one at the end of the Cretaceous that wiped out the dinosaurs 65 million years ago.
Thus, if humanity’s greenhouse gas emissions continue to rise, roughly a third of all marine animals could be gone in 300 years.
Our efforts are not enough
Although there is broad consensus that a move away from coal and the expansion of wind and solar power makes a worst case scenario in this future unlikely, oil and gas use continues to rise and the world is not , by no means, on the way to meeting the lowest emissions scenario modeled by scientists.
While the study focused on the effects of warming and oxygen loss, ocean acidification and other snowball effects could worsen the predicted species loss. And it is that marine animals have physiological mechanisms that allow them to cope with environmental changes, but only to a certain extent, experts say.
“Extreme warming would lead to climate-driven extinctions that, near the end of the century, will rival all current human stressors combined,” the authors write in their study published in the journal Science.
Of course, reversing greenhouse gas emissions – for which we still have time – could reduce the risk of extinction by more than 70% , experts say. Under the worst emissions scenarios, the losses would be on par with the five worst mass extinctions in Earth’s history; something we should not allow.
The world has already warmed more than 1 degree Celsius since the pre-industrial era , and the oceans last year contained more heat energy than at any time since records began six decades ago.
Referencia: Justin L. Penn and Curtis Deutsch. Avoiding ocean mass extinction from climate warming. Science • 28 Apr 2022 • Vol 376, Issue 6592 • pp. 524-526 • DOI: 10.1126/science.abe9039
