By 2300, if humanity fails to curb warming-causing greenhouse gas emissions, life in the oceans will face a possible mass death comparable to Earth’s massive extinctions, a study published Thursday in the journal Warns found.

But the paper’s authors, Justin Penn and Curtis Deutsch, who have ties to both Washington University and Princeton University, said limiting global warming to 2C above pre-industrial levels would prevent such a disaster.

These scientists used eco-physiological models to weigh physical species boundaries against predicted sea temperatures and depleted oxygen levels; this was a particularly challenging task as there had been no previous research on the subject.

The results were alarming: If global warming continues as it has so far, marine ecosystems around the planet could experience a mass extinction comparable to that at the end of the Permian, known as the Great Dying.

This happened 250 million years ago and caused the extinction of more than two-thirds of marine fauna due to warming and oxygen depletion, which is similar to today’s conditions.

As the tropical oceans lost most species, many of these areas would migrate to higher latitudes to survive.

On the other hand, polar species will disappear en masse, as habitat types will disappear from the planet altogether.

The document states that limiting it to 2°C, the upper limit of the target set by the Paris Agreement, would “reduce extinction severity by more than 70% and prevent a mass extinction in the seas”.

According to UN climate experts, the preferred target of limiting warming to 1.5°C is impossible to achieve with existing international commitments.

“As marine extinctions have not progressed as much as terrestrial ones, society has time to turn the tide in favor of marine life,” scientists Malin Pinsky and Alexa Fredston said in an accompanying comment.

“Exactly where the future lies between best and worst-case scenarios will be determined by the choices society makes about not only climate change but also habitat destruction, overfishing and coastal pollution,” he said.