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About 252 million years ago—at the end of the geologic period known as the Permian—roughly 96 percent of marine animals were lost in the largest extinction event in Earth’s history. Around that same time, in what is now Siberia, ongoing volcanic eruptions released massive amounts of greenhouse gases into the atmosphere, causing rapid increases in temperatures worldwide. Until now, scientists have been unsure which aspects of the changing climate were the greatest contributors to the mass extinction.
In a study published today (December 6) in Science, researchers combine models of animal metabolism and the conditions in ancient oceans to attribute what’s called the Great Dying to two main causes: ocean waters heating up and losing oxygen. While current climate conditions are nowhere near as severe as they were during that time period, the burning of fossil fuels has already led to a loss of oxygen and warming ...
