All in all, though, the most likely cause of an apocalypse will be some combination of all of those things. A population weakened by disease, overcrowding, and famine finds itself unprepared for a robot uprising, nuclear war or fungus. Basically, the film Interstellar could happen and there'd be no Matthew McConaughey searching for a way to save everyone. Expert Joseph Miller is a proponent of this snowball effect being what eventually claims the Earth. Which would make the end times less apocalyptic and immediate, like being attacked by a saber-toothed tiger. It's more like being nibbled to death by ducks. Which sounds adorable, but remember, it involves the end of everything. On a smaller scale, even, a pandemic could occur through some part of our delicate ecosystem like, what if that fungus started affecting bees which would have the chain reaction of messing up the food chain, and exacerbating an existing problem like overpopulation or lack of food thanks to global warming. Good news: you don't need to worry about any of these predictions coming true. Bad news: you have to worry about all of them coming true at the same time.