A 2 km diameter asteroid impact on Earth would result in catastrophic destruction, obliterating an area comparable to a large state or small country, and creating a 30 km crater. If it struck the ocean, it would trigger massive tsunamis affecting coastlines worldwide. The impact would release significant dust into the atmosphere, leading to drastic climate changes and global crop failures. Additionally, the ozone layer could be severely damaged, causing widespread ecological disruption and numerous species extinctions, though not necessarily a mass extinction event. The discussion highlights the severe consequences of asteroid impacts, referencing historical events like the one that contributed to the extinction of the dinosaurs.