Overview
- The peer‑reviewed paper published July 28 in Journal of Geophysical Research: Biogeosciences combines earlier impact simulations with measured properties of an extinction‑age fine dust layer to model post‑impact heating.
- Including the fine dust raises modeled surface heating about 3.5 times versus spherules alone and yields thermal doses the authors say could reach roughly 17 times a human lethal level.
- Authors conclude the dust‑insulated heat pulse could have killed many unsheltered terrestrial animals within an hour or two and sparked widespread fires by igniting grass, lichen and other easily lit fuels.
- The same dust layer in the models then reduces sunlight for years to decades, creating a prolonged post‑impact cold and food‑shortage phase that would have finished off remaining survivors.
- The hypothesis links immediate thermal mortality to longer‑term ecosystem collapse but hinges on broader sedimentary evidence because strong wildfire signals so far are concentrated in North America, notably the Tanis deposit.