ScienceExtreme global warming could see major ocean life extinction

Extreme global warming could see major ocean life extinction


A computer model based on past mass extinctions predicts the percentages of marine organisms that may be lost in best and worst-case scenarios



Environment



28 April 2022

Fish in the Ceram Sea off Indonesia

Fish in the Ceram Sea off Indonesia

Alex Mustard/Nature Picture Library/Alamy

How badly will ocean animals be hit as Earth warms? A computer model based on the oxygen requirements of marine organisms may provide an answer.

Our oceans already contain about 2 per cent less oxygen than 50 years ago, because the gas is less soluble in warmer water. Many organisms are therefore moving polewards to cooler regions. As the oceans continue to warm, some will be left with nowhere to go, with polar species being hit hardest.

To better understand the scale of the risk, Curtis Deutsch at Princeton University and Justin Penn at the University of Washington in Seattle have developed a model that predicts when animal species may go extinct. This is based on projections of when the amount of suitable habitat available to marine species will fall below a critical level, due to oxygen declines.

They calibrated their model using data from past mass extinctions. The model doesn’t take into account other pressures on marine life, such as overfishing, pollution and the loss of coral reefs from bleaching.

Nevertheless, the model suggests marine extinctions will rise gradually alongside ocean warming, passing 10 per cent once around 6°C of warming on average across the seas is reached. After 8°C, the percentage will increase more rapidly, passing 40 per cent at around 14°C of warming.

One key uncertainty is how quickly marine organisms will colonise new habitats. If they move more quickly than in the median scenario, the proportion of species going extinct would remain well below 5 per cent until around 8°C of warming.

The paper cites the 2021 report by the Intergovernmental Panel on Climate Change (IPCC) to show temperature increases of this magnitude are possible.

“Under the high-emissions scenario, surface air warming could reach… 10° to 18°C over the next three centuries,” the paper states. However, this high-emissions scenario isn’t considered likely and the world is thought to be heading for around 3°C by 2100.

“We aren’t predicting the future or taking anything as a given,” says Deutsch. “We are saying that still plausible projections of the future will result in a mass extinction. Scenarios that mitigate strongly will avoid that outcome.”

Writing in an editorial that accompanies the research, Malin Pinsky at Rutgers University in New Jersey said: “Fortunately, greenhouse gas emissions are not on track for the worst-case scenario.

“How close to the best-case scenario human society can hew, however, remains one of the most pressing questions for the future of life in the oceans.”

Journal reference: Science, DOI: 10.1126/science.abe9039

More on these topics:



Original Source Link

Latest News

Kristin Cavallari Is NOT Moving In With BF Mark Estes Despite Putting Tennessee Home Up For Sale! Here’s Why!

Are Kristin Cavallari and Mark Estes taking the next step in their relationship and moving into a house...

12 years later, Sandy Hook seniors prepare for graduation

The survivors experienced one of the deadliest school shootings in U.S. history. Like graduating seniors everywhere, members of Newtown...

Donald Trump Commits to Championing Bitcoin Mining in DC

Today, Donald Trump met with Bitcoin Magazine's CEO David Bailey and several prominent U.S. Bitcoin miners. The meeting...

US inflation falls to 3.3% in May in boost to markets

Unlock the US Election Countdown newsletter for freeThe stories that matter on money and politics in the race...

Metallica is headlining Fortnite’s next concert

It’s sad but true: Metallica is coming to Fortnite. Epic just announced that the group will be featured...

Must Read

Ransomware Is ‘More Brutal’ Than Ever in 2024

Today, people around the world will head to...

Christine Lagarde says ECB can keep rates on hold as long as needed

Unlock the Editor’s Digest for freeRoula Khalaf, Editor...
- Advertisement -

You might also likeRELATED
Recommended to you