The acidification of the Earth’s oceans, which climate scientists warn is a dangerous effect of continued carbon emissions, was behind a mass extinction event 66 million years ago, according to a new study.

Small-shelled marine organisms survived the meteorite that struck the Earth and wiped out the dinosaurs, according to researchers at the GFZ geosciences research center in Potsdam, Germany, but the subsequent sharp drop in pH levels in the ocean caused the marine life to go extinct.

“We show ocean acidification can precipitate ecological collapse,” Michael Henehan, who led the study, told The Guardian.

Researchers examined shell fossils in sediment dating back to the time period just after the meteorite struck the planet…