News Life Mega El Niños kicked off the world’s worst mass extinction Most species died off during the Great Dying 252 million years ago The vast majority of Earth’s species died out at the end of the Permian Period, as illustrated here. The largest mass extinction yet has its roots in El Niños that grew increasingly stronger as an outpouring of greenhouse gases warmed the global climate. Lynette Cook/Science Source Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Jake Buehler September 12, 2024 at 2:00 pm A barrage of intense, wild swings in climate conditions may have fueled the largest mass extinction in Earth’s history.