NEW HAVEN, Conn., April 26 (UPI) -- New research discredits the theory that intense volcanic activity and a rapid rise in CO2 levels precipitated the demise of the dinosaurs.
Some 65 million years ago, more than 75 percent of all plants and animals perished in a mass extinction event. Some researchers have suggested volcanic eruptions and a plethora of CO2 triggered ocean acidification.
To test the theory, scientists at Yale University analyzed sediment samples for markers of ancient acidity levels. Their findings suggest the planet's oceans experienced a brief episode of ocean acidification as a result of volcanism, but that the depressed pH levels were neutralized prior to the mass extinction.
The research team shared their results in the journal Philosophical Transactions of the Royal Society B.
"Combining this with temperature observations that others have made about this time, we think there is a conclusive case that although Deccan volcanism caused a short-lived global warming event and some ocean acidification, the effects were cancelled out by natural carbon cycling processes long before the mass extinction that killed the dinosaurs," lead study author Michael Henehan, a postdoctoral associate at Yale, said in a news release.
Henehan and his colleagues say their work is not in contradiction with modern climate science. Volcanism at the end of the Cretaceous period released CO2 across an expansive timescale, offering the ocean plenty of time to normalize.
"However, if you cause big disturbances over rapid timescales, closer to the timescales of current human, post-industrial CO2 release, you can produce not only big changes in oceanic ecosystems, but also profound and long-lasting changes in the way the ocean stores and regulates CO2," Henehan said.