Throughout the Permian, there was a lot of life on Earth. And so the available carbon was light on the light kind and heavy on the heavy kind. Then, about 250 million years ago, the rocks record a sudden influx of light carbon. “This can hardly be explained by natural processes,” says Korn. “Something was wrong with the carbon cycle, and the main hypothesis is that there were these big volcanoes in Siberia. An extremely big volcano burnt all the organic material in this area, and this was then the source of the light carbon.”
