The oceans may be acidifying faster today than they did in the last 300 million years, according to scientists publishing a paper this week in the journal Science.
“What we’re doing today really stands out in the geologic record,” says lead author Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory…
“These scientists have synthesized and evaluated evidence far back in Earth’s history,” said Candace Major, program officer in the National Science Foundation’s (NSF) Division of Ocean Sciences, which funded the research.
“The ocean acidification we’re seeing today is unprecedented,” said Major, “even when viewed through the lens of the past 300 million years, a result of the very fast rates at which we’re changing the chemistry of the atmosphere and oceans.”
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More catastrophic events have happened on Earth before, but perhaps not as quickly.
The study finds two other analogs for modern day ocean acidification–the extinctions triggered by massive volcanism at the end of the Permian and Triassic eras, about 252 million and 201 million years ago, respectively.
But the authors caution that because ocean sediments older than 180 million years have been recycled back into the deep Earth, scientists have fewer records to work with.
During the “Great Dying” at the end of the Permian, about 252 million years ago, about 96 percent of life disappeared.
Massive eruptions from what is known as the Siberian Traps in present-day Russia are thought to have triggered earth’s biggest extinction.
Over 20,000 years or more, carbon in the atmosphere rose dramatically.
Oceans Acidifying Faster Today Than in Past 300 Million Years – US National Science Foundation (NSF)