Animation of an asteroid impact near the city of Barcelona, Spain. Such an impact would have a devastating effect on the region, and a large impact could have global consequences too. Asteroid impacts have occurred throughout Earth磗 history, with large impacts thought to have been responsible for several mass extinction events, most notably the death of the dinosaurs around 65 million years ago. Such impacts cause rapid climate change as dust and other ejecta in the atmosphere block sunlight, leading to cooling.