According to a new study, if climate change continues at its current rate, life in Earth’s oceans could experience mass destruction — a loss in biodiversity that could compete with the planet’s past great extinctions.
The discharge of huge amounts of anthropogenic greenhouse gasses into the air is altering the climate system of the Earth, thereby putting the lives of several species at greater risk of extinction.
But the impact of climate change on global biodiversity is still uncertain, especially for the planet’s huge marine menagerie. Besides direct human impacts, such as overfishing, habitat destruction and coastal pollution, marine species are highly subjected to threats of climate-driven oxygen depletion and ocean warming.
While earlier mass extinction events as a result of the global environmental changes are demonstrated by the fossil record, the future of ocean life as one knows it under runaway climate change remains doubtful.
Justin Penn and Curtis Deutsch assessed the extinction threat for marine species throughout climate warming scenarios with the help of comprehensive ecophysiological modeling, which weighed a species’ physiological limits with projected marine oxygen and temperature conditions.
The authors discovered that under “business as usual” global temperature rises, marine ecosystems planet-wide are likely to experience huge extinctions possibly rivaling the size and intensity of the end-Permian extinction — the so-called “Great Dying.”
This happened approximately 250 million years ago and contributed to the death of over two-thirds of marine animals.
Penn and Deutsch’s model disclosed patterns in the extinction risk in the future. While tropical oceans are anticipated to lose the majority of the species under climate change, many will migrate to greater latitudes and more favorable conditions.
But across the world, polar species are likely to go extinct, as their habitats will fade away completely
“Climate change is, in effect, walking species off the ends of the Earth,” wrote Malin Pinsky and Alexa Fredston in a related Perspective.
But the study also indicates that decreasing or reversing greenhouse gas emissions can result in extinction risks by as much as 70%.
Pinsky and Fredston wrote, “With a coordinated approach that tackles multiple threats, ocean life as we know it has the best chance of surviving this century and beyond.”
Penn, J. L. & Deutsch, C. (2022) Avoiding ocean mass extinction from climate warming. Science. doi.org/10.1126/science.abe9039.