Smoke on the water

Fallout from burning coal may have choked the life out of 90 percent of marine species some 250 million years ago, Canadian researchers argue in the Jan. 23 Nature Geoscience. Huge quantities of carbon-rich char fell on the high Arctic prior to the Permian mass extinction of marine organisms, the scientists found. Based on the carbon’s geology and chemistry, the researchers propose that it traces back to the natural combustion of Siberian coal and organic-rich sediments. Being “remarkably similar” to modern coal fly ash, the char would have been toxic to aquatic life and ultimately would have dispersed globally, the researchers say.