Because the world is going to end tomorrow, I don't have to worry about what I'm going to write next week. But because the world still exists today, I'll write about what would happen if the world was actually going to end.
I'm not a prophet. I'm just a humble 20-something with a keyboard. But you're welcome.
I have a feeling "the end of the world as we know it" won't just happen one day. It won't have a specific start and end date. More likely, it will be a gradual decline. The fact that Donald Trump is no longer in the presidential race is a good sign that the world will not end anytime soon.
At this rate, it's most likely this will happen.
Another possibility (one that I like much better) is that Star Trek: First Contact will come to life. Wars and general disrespect will make our planet suck, and we'll develop warp drive to get the hell out. Aliens will happen to pass by at the moment we test it. They'll come down to Earth to welcome us to the menagerie of intelligent life forms in the universe.
And then they'll realize they don't want us anywhere near them because we're way too destructive. So they'll blow us up.
The ship that was testing warp drive will get away, with one man, one woman, a tarantula, and a kiwi bird on board (they're from Australia). They'll head off to Betelgeuse, figuring to put some good distance between themselves, Earth That Sucked at the End, and the aliens responsible for obliterating humanity. And Betelgeuse, they'll discover, is home to another sentient alien species, one who is completely unaware of humanity's penchant for destruction and DOOM.
But these new aliens have an extra sense that humans don't. We can smell particular odors; they can smell death. And they know that these last two humans just came from a place where many voices suddenly cried out in terror, and were suddenly burned to a crisp. And the aliens will get suspicious.
These are benevolent aliens, though, willing to hear our travelers' stories. They listen patiently while the weary and heart-sore visitors explain their plight, managing to leave out the bit about why the other aliens destroyed the Earth. And so the last two humans are granted a safe place to stay on Betelgeuse IV (stupid aliens), in exchange for sharing their knowledge of Earth That Sucked at the End.
Oh, and recreating the human race.
Except the man, it turns out, is infertile, and the woman doesn't even have ovaries. Because Earth That Sucked at the End had so much radiation that most people had that problem.
And that is how the human race will end.