Actually, during the end of the Permian (about 252 million years ago) there was a large extinction event, which killed even more animals than the one that killed the dinosaurs. More than 90% of all the animals in the oceans were killed during that time and many animals on land as well. We do not know exactly why the animals died although there is a lot of evidence that large volcanic eruptions could have caused it. Some scientists found evidence that the oceans became very acidic, which would harm ocean organisms.

Catastrophes like the extinction of the dinosaurs and the end of the Permian killed many animals. However, these happen very rarely, and life has continued. That is why I think that even if we have a catastrophe, life will still adapt and survive.

What apocalypse?

Based on our current models of how stars work, the sun will become large enough to envelop the earth in about five billion years' time. The earth will be too hot to live on long before then.

Any number of other events could happen sooner that you might call 'apocalyptic', but they are on different scales. A global thermonuclear war, for example, might destroy human civilization, but wouldn't wipe out all life on the planet.