In case you weren't already worried about the current and rapid acidification of the world's oceans, a new report by leading scientists finds that this very phenomenon is to blame for the worst mass extinction event the planet earth has ever seen—approximately 252 million years ago.
The findings, published this week in the journal Science by University of Edinburgh researchers, raise serious concerns about the implications of present-day acidification, driven by human-made climate change.
"Scientists have long suspected that an ocean acidification event occurred during the greatest mass extinction of all time, but direct evidence has been lacking until now," said lead author Dr. Matthew Clarkson in a statement. "This is a worrying finding, considering that we can already see an increase in ocean acidity today that is the result of human carbon emissions."
The paper looks at the culprit behind the Permo-Triassic Boundary mass extinction, which wiped out more than 90 percent of marine species and two-thirds of land animals, making it even more severe than the die-off of the dinosaurs.
The scientists evaluated rocks in the United Arab Emirates that, 250 million years ago, were on the bottom of the ocean. Researchers then employed a climate model to determine what drove the extinction.
A summary of the researchers' findings explains the mass die-off "happened when Earth’s oceans absorbed huge amounts of carbon dioxide from volcanic eruptions. This changed the chemical composition of the oceans—making them more acidic—with catastrophic consequences for life on Earth."
The kicker? The carbon that drove this process during the Permian-Triassic Boundary extinction was "released at a rate similar to modern emissions," the report summary concludes. "This fast rate of release was a critical factor driving ocean acidification."
As Dr. Rachel Wood of the University of Edinburgh told the Independent, "The important take-home message of this [report] is that the rate of increase of CO2 during the Permian mass extinction is about the same rate as the one to which we are exposing the ocean to today."