- Tropical waters would experience the greatest loss of biodiversity, while polar species are at the highest risk of extinction.
- Climate-driven ocean warming and oxygen depletion would be the primary reasons for the potential mass extinctions.
- The extinctions could occur in the next 100-300 years.
Unless climate change is curbed, Earth’s oceans could see a mass extinction of marine life unlike anything the planet has seen for millions of years, according to a new study published Thursday.
“If carbon dioxide emissions accelerate unchecked over the next century, this would lead to extreme warming, driving extinctions in the ocean rivaling the mass extinctions in Earth’s past,” study lead author Justin Penn of Princeton University told USA TODAY.
The study said that climate-driven ocean warming and oxygen depletion would be the primary reasons for the potential mass extinctions. In addition, direct human impacts, such as habitat destruction, overfishing and coastal pollution, also threaten marine species.
Watch:Earth Day — Satellites and climate change
NOAA:Methane emissions soared to a record high in 2021 in an ‘alarming’ trend
The burning of fossil fuels such as oil, gas and coal that power our world releases greenhouse gases such as carbon dioxide and methane into the Earth’s atmosphere and oceans.
As ocean temperatures increase and oxygen availability drops, marine life abundance plummets, according to the study.
The extinctions could occur in the next 100-300 years: “By 2100, in a high-emissions scenario, extinction risks could rival all human threats in the ocean as they currently stand, including overfishing and marine pollution among others,” Penn said.
“By 2300, these extinctions could rival those in the geologic past, unless trends in greenhouse gas emissions are reversed.”
According to the study, under “business as usual” global temperature increases, marine ecosystems planet-wide are likely to experience mass extinctions potentially rivaling the size and severity of the end-Permian extinction – the “Great Dying” – which occurred roughly 250 million years ago and led to the demise of more than two-thirds of marine animals.
LATER, GATOR?:One-fifth of all reptile species could go extinct, new study says
Tropical waters would experience the greatest loss of biodiversity, while polar species are at the highest risk of extinction, the authors reported.
Even though tropical oceans are expected to lose the most species under climate change, many will likely migrate to higher latitudes and more favorable conditions to survive. However, polar species are likely to go globally extinct, as their habitats will disappear from the planet entirely.
To conduct the study, Penn and his Princeton colleague Curtis Deutsch combined existing physiological data on marine species with models of climate change to predict how changes in habitat conditions will affect the survival of sea animals around the globe over the next few centuries.
The news wasn’t all bad, however: The study found that reversing greenhouse gas emissions could reduce the risk of extinction by more than 70%.
“The silver lining is that the future isn’t written in stone,” said Penn, a postdoctoral research associate in geosciences at Princeton, in a statement. “The extinction magnitude that we found depends strongly on how much carbon dioxide [CO2] we emit moving forward. There’s still enough time to change the trajectory of CO2 emissions and prevent the magnitude of warming that would cause this mass extinction.”
Deutsch, a professor of geosciences at Princeton, agreed, noting that “aggressive and rapid reductions in greenhouse gas emissions are critical for avoiding a major mass extinction of ocean species.”
The study was published in the peer-reviewed journal Science, a publication of the American Association for the Advancement of Science.