Fun fact: more than 99% of every species that’s ever lived is now extinct.
Here are a few ways humans could be next:
This seems like the most likely doomsday scenario because there’s over 22,000 active nuclear warheads out there, and some of them are in some pretty unstable hands (e.g. Kim Jong Un). We’re basically at the mercy of our political leaders not to let their emotions get away with them and start a nuclear war that ruins earth for everyone. If you don’t die in the actual nuking here’s a fate worse than death for you—in the aftermath of nuclear warfare the electromagnetic pulses would make modern technology like your beloved iPhone unable to function.
Could there be some kind Black Plague: The Sequel that would wipe out humankind? Probably. Haven’t you seen Contagion? The Black plague killed 75 million people, unintentionally. With someone intentionally harnessing a virus as a biological weapon, it’s not much of a stretch.
A supervolcano is just like a regular volcano…except it
produces thousands of times more lava and ash that leads to indefinite climate change—like an ice age. Of course people immediately surrounding the area (30-40 mile radius) will be covered in lava, but the amount of ash in the air will block the sun and cool the earth’s temperature as a fun treat for those who survive the initial supereruption.
Hostile robot takeover
You’ve seen Terminator, right? In all seriousness, the technological singularity (when our computers become self aware) is a real thing that a lot of smart people believe will happen at some point (as soon as in the next 10 years). These robots will be far superior to humans, intelligence-wise, and there’s really no good argument for why they wouldn’t prefer to knock us out of existence, or at least enslave us to do their bidding.
Most scientists that think intelligent extraterrestrial life is possible, don’t think they’re of the friendly E.T. variety. Stephen Hawking says, “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach.”
The sun could die
The sun is a star, and stars don’t live forever—we see them fall out of the sky all the time. Don’t worry though, if this happens doomsday would occur long before the sun actually stopped burning, first the sun would expand—drying all our oceans and broiling pretty much everyone and making Earth uninhabitable.
In Jurassic Park all the dinosaurs seem super big and scary. If they can’t survive an asteroid impact with earth, how can humans have any hope? Wikipedia says, “For this to occur the asteroid would need to be at least 1 km (0.62 mi) in diameter, but probably between 3 and 10 km (2–6 miles). Asteroids with a 1 km diameter have impacted the Earth on average once every 500,000 years.” How would our buddies at NASA help us deal with this crisis if we realized an impact event was about to occur? Send Bruce Willis up into space on a rocket ship? Nope. Their official advice in this scenario is, “Pray.”