Thinking beyond the data: When the sea went dark

Five mass extinction events in earth's history each resulted in major oceanic species loss. All of these appear to be associated with significant atmospheric aerosol loading and a reduction in sunlight intensity at the surface. Importantly for marine species, it is not only the intensity of the incident light, but also its colour that is important as, within the ocean, only light with wavelengths less than about 550 nm penetrate to significant...