The end-Cretaceous (or K-Pg) extinction is one of the best known mass extinctions in Earth's history, primarily because that is when non-avian dinosaurs disappeared. Although the popular idea is that an asteroid impact was what caused the extinction, the science hasn't actually been that clear. More recently, a second hypothesis has challenged the idea asteroid as the main culprit, suggesting that huge volcanic eruptions in what is now India called the Deccan Traps was responsible. It has also been suggested that dinosaurs were already in decline when these things happened, speeding up the inevitable.

In this interview, we speak with Dr Alessandro Chiarenza, a research associate at University College London about his new paper published today in PNAS showing that it really was the asteroid impact that killed the dinosaurs. This new study, based on research he did during his PhD at Imperial College London, uses a large amount of data put into climatic models to analyse different scenarios caused by an asteroid impact, the Deccan Traps volcanism, and a combination of the two. This study showed that the asteroid caused a prolonged impact winter, causing the extinction of the dinosaurs.