Climate crisis threatens to wipe out almost all sea life, scientists warn

A paper published in the journal ‘Science’ found that accelerating greenhouse gas emissions could culminate in a mass extinction not seen for 250 million years

Limiting the temperature rise to 2 degrees Celsius would reduce the risk of mass extinction by more than 70 per cent, the scientists said

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An empty sea is seen in Thailand’s Maya Bay. Accelerating greenhouse gas emissions could ‘culminate in a mass extinction rivalling those in Earth’s past’, scientists said. Photo: Reuters

Published: 12:06pm, 29 Apr 2022

Scientists warned that a failure to curb carbon emissions may result in the extinction of most marine life, an emptying of the ocean last seen 250 million years ago amid a rapidly warming climate.

Accelerating greenhouse gas emissions could “culminate in a mass extinction rivalling those in Earth’s past”, stated a peer-reviewed paper published on Thursday in the journal Science.

There is still time, though, to forestall such a global catastrophe, the scientists said. Limiting the temperature rise to 2 degrees Celsius would reduce the risk of mass extinction by more than 70 per cent, according to the paper.

A green sea turtle at Heron Island, Australia. Ocean temperatures are rising to record highs and oxygen levels are falling. Photo: Hannah Le Leu/Underwater Photographer of the Year 2022

“The future isn’t yet written,” said Justin Penn, an associate research scholar at Princeton University and lead author of the study. “It’s not too late to reverse the greenhouse gas emissions trends to avoid mass extinction in the ocean from climate change.”

If the future remains a blank page, the past consequences of extreme climate change are written in the marine fossil record. In a 2018 study, Penn and co-author Curtis Deutsch created a computer model to simulate the warming of the world in the late Permian Period 250 million years ago when volcanic eruptions released huge quantities of greenhouse gases into the atmosphere.

They found ocean surface temperatures increased by more than 10 degrees, triggering a nearly 80 per cent decline in marine oxygen levels. An examination of the fossil record confirmed that oxygen-depleted warming seas killed off up to 96 per cent of marine species.

Today, ocean temperatures are rising to record highs and oxygen levels are falling. “The same mechanism that would be driving species losses from human-induced climate change has been shown to have caused extinction in the geologic past,” Penn said.