In countless post-apocalyptic stories, the new world is a rough place where dominance is decided through combat. Men and women will punch one another into submission, unconsciousness or even death. But that’s not the best way to settle things, as fights can lead to injuries that would be incredibly debilitating in a world without doctors.
An ongoing theme in post-apocalyptic stories is that the biggest danger is other humans. That’s how The Walking Dead pushes its story along — half the people our heroes encounter turn out to be evil. However, this doesn’t make sense, because humans naturally want to work together. It’s part of both our nature and our biology.
The biggest dangers survivors encounter in fiction are other bands of people and whatever creatures caused of the apocalypse. However, one of the biggest problem survivors will have to deal with are roaming packs of dogs. By nature, dogs are pack animals that will naturally form hunting groups. This would happen quickly — in the wake of Hurricane Katrina there were dog packs, and they’re still a problem 10 years after the storm. It’s even becoming a big problem in Detroit, because their population has decreased so much.
One of the perks of being the only one left alive is that you can take any car you want and speed along the empty highways. But you better enjoy it while it lasts, because gas has a short shelf life. Untreated, gas can go bad within 90-100 days. Unless more gas is refined, after about three months there simply wouldn’t be enough gas for cars and generators.
The biggest problem, and one which may render every other issue moot, is that there are 437 nuclear reactors worldwide and another 71 being built. A post-apocalyptic world would have deadly nuclear disasters scattered throughout it. In the simplest terms, a nuclear reactor essentially works like a kettle. It boils water, which powers steam turbines, which creates electricity. The problem is that these reactors need to be constantly watched. If they aren’t taken care of, they overheat and create a meltdown.
Without anyone taking care of the reactors, after about 10 days most would start to meltdown. Not only would there be nuclear explosions across the world, but radiation would spew into the atmosphere and poisonous clouds would blow across the planet. Many places, especially in North America, parts of Asia, South America and Europe, would simply be inhabitable.