Causes and climatic consequences of the impact winter at the Cretaceous-Paleogene boundary

However, debate remains about the causes and consequences of this "impact winter." We perform simulations of the Chicxulub impact with an Earth system model that can simulate the evolution of extreme aerosol loading to quantify the climatic responses to emissions (soot, sulfur, and dust) associated with the impact winter.

We show that all impact winter emissions can drastically reduce surface temperature and precipitation. However, only soot emission from impact-driven firestorms is capable of reducing light to below the photosynthetic threshold for many months. Therefore, our results suggest that widespread fires may have been necessary to produce the observed pattern of marine extinction across the Cretaceous-Paleogene boundary.