The Current Rate of Ocean Warming Could Bring the Greatest Extinction of Sealife in 250 Million Years

 

https://insideclimatenews.org/news/28042022/ocean-extinction-climate-change/

 

 By Bob Berwyn
April 28, 2022

 

If greenhouse gas pollution remains unchecked, global warming could trigger the most catastrophic extinction of ocean species since the end of the Permian age, about 250 million years ago, scientists warned in a new study today. During the end-Permian Extinction, researchers estimate up to 90 percent of marine organisms died out in overheated, acidic and deoxygenated oceans.

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That cataclysmic change may have resulted from giant volcanic eruptions that went on for 2 million years. But a 2021 study suggested that carbon dioxide emissions from current human activity are twice as high as those that caused the Permian climate to shift.

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Global greenhouse gas concentrations are reaching new record levels each year, and Deutsch said that, given the political and economic uncertainties highlighted by events like the invasion of Ukraine, the possibility that diplomatic efforts to curb warming could fizzle can’t be ruled out.

Malin Pinsky, a Rutgers ecologist and evolutionary biologist who wrote a Perspective article about the new research by Deutsch and Penn, said global policy choices the last few decades have already prompted massive and rapid ocean changes, such as sea level rise, ocean acidification and global shifts of species, which are affecting food security in developing countries. More than half of all human-caused CO2 produced since 1750 have been emitted in just the last 30 years.

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Oceans have absorbed more than 90 percent of the excess heat trapped on the Earth’s surface by greenhouse gas pollution, building up at a rate equivalent to five atom bomb explosions per second. The average ocean temperature has reached record highs almost yearly, and its surface waters have grown 30 percent more acidic in the past 200 years.

Hot water is already killing marine life, and has perhaps already resulted in extinctions of regionally endemic species, especially during extreme events like marine heat waves.

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