The worst mass extinction in Earth's history may have been caused by a supercharged El Niño cycle.
New research suggests that an overload of carbon dioxide in the atmosphere led to the climatic shift, which, in turn, killed 90% of the species on Earth around 250 million years ago, at the end of the Permian period. The finding has implications for modern climate science: Researchers don't know how current warming will affect the El Niño-La Niña cycle, but even a fraction of the disruption resulting from the world's worst mass extinction would make life for humanity very difficult.
