10 ways the world could end, maybe

We offer 10 of our favorite doomsday scenarios—to the best of our ability to understand and explain them.

In some of these cases, we would see a swift and sudden oblivion. In others, what would really do us in is the chaos that would result; in short, we would off ourselves (or severely reduce our numbers). Whether it’s the end of Earth or just the end of humanity, for our purposes, it’s much the same thing.

1. Something weird and sciency happening to the planet.

There are a ton of ideas astronomers like to bounce around on their lunch breaks. Some highlights:

A black hole approaching the solar system, pulling Earth out of orbit—or just pulling us apart. 
A sudden burst of devastating cosmic radiation—like from an exploding star—blinding us, boiling our atmosphere, giving us cancer, and killing everything that produces oxygen. (The nearest star likely to do this is 8,000 light-years away, so there’s time…)
A sudden change in the sun’s output, which could freeze us or fry us. Also, notably, the sun is due to die out in about 5 billion years, at which time it will expand to consume Mercury, Venus and Earth.
Abrupt shifts in Earth’s magnetic field, or a complete flip-flop of the poles (which apparently happens every 250,000 years, and we’re about due) leaving us exposed to all manner of deadly cosmic radiation.

2. Asteroid, comet, meteor

It’s like “rock, paper, scissors,” but no one wins. This is perhaps the most cinematically explored option.

3. An extremely powerful geological event

Massive supervolcanic eruptions could lead to the oxymoronic “volcanic winter” by releasing extraordinary amounts of dust and toxic gases into the atmosphere, sending the planet into extreme global cooling and ice age—or global warming, if greenhouse gases prevail. Either way, we lose.

Good news: Scientists think this happened in Indonesia about 71,500 years ago and reduced the human population to only a few tens of thousands. So, not quite the end of the world.

Also, an extremely powerful geological event could knock Earth off its axis, leading to further major problems for inhabited parts of the planet.

4. Nuclear, chemical, or biological holocaust

A 2010 Ploughshares Fund report indicates that there are 22,000 active nuclear warheads scattered among the world’s nuclear-powered nations. What else is there to say about that?

But the end might not be so intentional (or avoidable). Never discount the possibility of a pandemic disease with a high mortality rate.

Of course, it could also be a human-made infectious agent—misanthropic mad-scientist stuff.

5. Loss of biodiversity

Some reports suggest that rate of species newly facing extenction is increasing, and if present trends continue, half of all animal species on Earth could vanish in 100 years. If the wrong species go, that could spell doom for humans, who (believe it or not) are dependent on things like the food chain, natural filtration of air and water, and pollination.

Also, some scientists fear that as patented, money-making genetically altered crops take over more and more of world agriculture, we are putting ourselves one blight away from a worldwide famine. Such crops may be resistant to pesticides, but that sort of encourages the development of super-pests. Those unbeatable species could quickly throw ecosystems off balance and knock humans a little further down the food chain.

6. Nanotechnology gone awry

There is some notion that self-replicating nanomachines (very, very tiny) could get out of control. In his 1986 book, “Engines of Creation,” nanotechnology pioneer Eric Drexler puts it like this:

“Imagine such a replicator floating in a bottle of chemicals, making copies of itself … The first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined.”

7. Alien invasion

You’ve seen the movies. You know how it’s going to go down.

8. Something religious

Most major world religions have some sort of Armageddon planned for us. If you believe in the eventuality of a final judgment day for all sinners and people of faith, whether it’s Qiyamah, Kali Yuga, the Rapture and the subsequent Tribulations of everyone left behind—or the awesome, terrible touch of His Noodly appendage—you might want to take precautions sooner rather than later for that. Are you ready for the final great battle between good and evil?

8. The “God Particle” (speaking of religion)

Scientists at the Large Hadron Collider near Geneva use enormous amounts of energy to smash protons together in an effort to understand some of the basic laws of subatomic particles, among them, something they are calling the “God particle.”

Some fear that a catastrophic chain reaction could create a subatomic black hole—which would really suck.

Others think an experiment gone wrong could produce a bit of strange matter called a strangelet—short for “strange nugget.” Normally strange matter decays too fast to cause harm, but it if should become stable, it could turn all nearby ordinary matter into strange matter, eventually consuming the world.

What that means, who can say? But let’s not find out.

10. Zombie apocolypse

What, you thought I’d forget zombies?