# How can I kill every human on earth? [closed]

One day, "God" said to me:

You need to eliminate the humans race!

So, I was thinking at this problem: How can I kill every human on the planet (and then kill myself)?

Some ideas:

• Nuclear Bomb - Bad choice.. Very difficult to build and A LOT OF PEOPLE will survive to the explosion.
• Diseases - Bad... Always will have people that are immune to it.

The best idea so far was:

Build an ideology that say everyone will be happy. And then kill for it! Like Mao Tse-Tung, Pol Pot, Hitler, Stalin, etc.. But even they did not even kill 1% of humanity.

So, what is the best strategy to do it?

• Adhere 'fricken' lasers to the heads of sharks. – Twelfth Nov 24 '14 at 20:50
• Is it a requirement that anything else survives? In other words, can I destroy the earth completely? – DJClayworth Nov 24 '14 at 23:15
• @Rodrigo welcome to WorldBuilding. Please edit into the question any constraints on timeframe and collateral damage (e.g. do we need to protect animals? The planet?) into the question. Thanks. – Monica Cellio Nov 24 '14 at 23:43
• Ask "God" for an asteroid. A big one. Preferably anti-matter. – Beta Nov 25 '14 at 0:28
• It disturbs me a little how many people seem to have given this matter an awful lot of thought. – Dawood ibn Kareem Nov 25 '14 at 2:08

I can't help myself.

1. Tell God to click that 'Halt Simulation' button - SE solution

2. Wake up whomever is dreaming us - Waking World solution

3. These aren't the humans you want to destroy - Jedi solution

4. Trans-locate God to parallel dimension where humans are already destroyed - 'The One' solution

5. Redefine 'humanity' to only include the guy standing in-front of you. Shoot him. - Semantics solution

6. Put rockets on Earth and slow its orbital velocity to 0, watch Earth fall into the Sun. - Physics Schmysics solution

7. Ask God to put in a trouble ticket and hope the problem disappears - Help Desk solution (attempting to redefine humanity as a feature may fit in here)

8. Invent Skynet. Implement Asimov's fourth law as "Ignore other laws, kill all humans".

• I was going to include "Import Bender from the future, give him a ray gun, and tell him to fulfill his life long dream - Futurama solution", but I didn't want to get caught up in fantasy ;) – Twelfth Nov 25 '14 at 18:31
• Think Globally, kill locally? – Twelfth Dec 10 '14 at 22:30
• Does halting simulation kill everyone? We always exist. – m4n0 Jul 21 '18 at 16:28

## Part 1: Reduce the human fecundity worldwide

The best way to ensure that eventual survivors can't repopulate the Earth is to make sure that they can't reproduce.

1. Do your best with genetic engineering. Create a huge variety of very different viruses that lead to human infertility but no other detectable symptoms, and make it transmissible by air and sexually. Make them transmissible to mosquitos, pigeons, cattle, rats, bats, cats and dogs, to ensure massive virus circulation. Make sure that the viruses spreads and infects people quickly, efficiently and silently.

BONUS: As suggested by @Henry Tailor in another answer, make the viruses induce production of pheromones on infected people, so they are more attractive than non-infected people.

1. Spread the viruses everywhere, in every city, town or indian village. You may simply convince or pay people for doing things that leads to that or maybe use a more technological approach and spray 'em with drones.

2. It will take some years for the scientists to understand what is going on and to discover, study and analyze the viruses. Many more to propose efficient ways to prevent further infection or promote efficient and widespread vaccines. Further, you designed a lot of very different viruses, not just one, so it is very unlikely that people will be immune to all of them. And they will need to be discovered, studied, analyzed and vaccinated independently each one in its own way.

3. When people becomes aware of the existence of at least some of the viruses (likely something between 2 and 8 years after you started to release them), spread misinformation about them, including misinformation in scientific reports and articles. Spread the type of misinformation (like fake news) that makes people paranoid, skeptical and more likely to spread the virus, and that also slows down scientific investigation.

4. Try to kill any scientists that are publishing seriously breakthrough work and studying what is going on. You may shot them down, poison them, trample them in the street, whatever. Make it looks like an accident or that some crazy fundamentalist guy (not you) did that. You will be unable to locate some of those scientists and it is hard to know what everyone is researching, but each kill is a point for you. Looking for people attending conferences on related topics is a great way to locate them.

Now, the fecundity drops worldwide, and fewer and fewer babies born each year. The scientists will start to work on it, and in-vitro fecunding will be a high profit business, but this is too few time (2 to 8 years) to efficiently address the issue or even to make everyone fully aware and non-skeptical, specially with widespread misinformation.

So, it is time to go to part 2 before the scientists make further progress.

## Part 2: Destroy the economy and make war

People need food to live. With few food available, people will die from hungry, and kill from hungry too, starting wars, crime and violence.

1. Atomic bomb major cities everywhere, all about the same time.

2. Spread orange agent, radioactive elements, poisons and/or viruses in plantations, waters and forests all around the world. This would make safe food really scarce.

3. Make each nation blame another one for the bombings and the destruction of crops, spread misinformations, fake news, manipulate media. This will trigger WW3.

Now the industry, the production and economy will be seriously damaged everywhere. The world is at the greatest war in the history. A lot of people dies. Survivors are struggling in the ruins, without anything safe to eat or to drink, people will run away to the countryside destructing whatever left from the economy there. The fertility problem is regarded to a second-plane and no one will be able to continue research on it anymore. There is just anarchy, crime, war, violence and misery.

Further, the chaos and anarchy will strongly benefit the spread and circulation of the viruses by moving a lot of people and resources around. People will likely disrespect any safety measures previously adopted to avoid further contamination, since getting food and water is always more important than this.

## Part 3: Game Over

In a few more years (let's say 15 years) at least 98% of the pre-existing population will be dead, and most of the survivors will be in bad health, miserable conditions and unable to have babies.

1. Now you just need to chase any possibly reproductive survivors. The easiest way to do that is to use drones to look for kids. When you find a kid, just shoot them (use your drones for that) and look for their parents somewhere around, and shoot them too. Or better, just shoot everyone alive, except if you guess that he/she might unintentionally show you where other survivors are hiding around, paying special attention for kids, then kill everybody. If you suspect that they are in a larger tribe or family, bomb the area for some days, search carefully using the drones and drop some radioactive dust in the area.

After a few more years, there would be no more than a few handful survivors around, probably less than 1000 in the entire world. They are too scattered, hidden and fearful to recolonize the planet, even if they have any mean to communicate. Even if a few kids survive and reach adulthood and can reproduce, they are still too few and too scattered to make the human race survive, so the humans will become extinct soon.

Mission accomplished. It took something like 20 to 30 years, but it is finally done. Now the last step:

1. Kill yourself (as demanded by the OP).

Note: Obviously I do not support anything of this. I am writing this like a film or game maker, and not because I believe that.

• If you can engineer a virus that silently sterilizes the entire population and reliably distribute the virus among the entire planet... wouldn't it be better to engineer a deadly virus with a long enough incubation period to infect the planet before discovery? If humanity dies within a very short time, there's not much of a chance of coming up with a defense, but even if you stop reproduction overnight, that gives scientists 30 years or more to find a solution -- there's no way to reliably identify every scientist working on a solution so you can kill them yourself. – Johnny Nov 25 '14 at 1:42
• @Johnny The part of reliable identify scientist is fixed. You don't need to identify everyone, just some (the most, the better). A deadly virus with long incubation period may make people aware when it kills people with rare genetic or medical conditions too early and infected people would still be reproducing. The catch is to sterilize everyone and start the war and genocide before the scientist can make enough work to find a solution, stopping research. Even if somebody finds a solution for one of the viruses, there still a lot of them. – Victor Stafusa Nov 25 '14 at 1:52
• Victor, you should find a way of linking this answer to your recent meta post ;-) – Rand al'Thor Dec 21 '14 at 21:26
• How difficult would it be to create such a virus? Say, some 'walking dead' kind of virus? It should be both lethal ab complex – real_yggdrasil Jul 20 '18 at 22:28
• @real_yggdrasil No, they should not be lethal. Re-read step 1: "Create a huge variety of very different viruses that lead to human infertility but no other detectable symptoms" - the idea is just to prevent that new babies born without making people aware so the many types of viruses should fly below the radar as long as possible. Also as I say in step 3: "you designed a lot of very different viruses, not just one, so it is very unlikely that people will be immune to all of them. And they will need to be discovered, studied, analyzed and vaccinated independently each one in its own way." – Victor Stafusa Jul 20 '18 at 22:46

A lot of credit goes to Peteris for turning this answer around.

I'll go with some kind of bacterium (or virus; I believe it works in this scenario) that stops photosynthesis in plants. Typically, chlorophyll can only be destroyed at low temperatures. That's a problem, because you can't drastically lower the temperature of a plant! But you could attempt to destroy the chloroplasts, the structures that contain the chlorophyll. My suggestion for this would be to create a virus that hijacks lysosomes - the organelles in a cell that break down other organelles - and breaks down chloroplasts. There is a problem - plants don't have lysosomes! However, vacuoles may be able to do the job. If you can destroy the chloroplasts, you can kill plants, and thereby the entire food chain of Earth. It might not happen within 50 years, but perhaps it could work within a century.

Note: I asked a question on Biology regarding the feasibility of the original process described in my answer. It can be found here.

Spontaneously, I see three approaches:

Diseases

First off, to everyone saying diseases aren't capable of eradicating the human race: You obviously never win at Plague inc. °v° Seriously though, diseases are a bad choice. While you might be able to kill a good percentage of the humans with some resistant killer virus, the infection rate would gradually slow down when the number of humans decreased, thus decreasing the number of chance meetings and resulting infection in combination with the fear of those remaining healthy, causing them to stay isolated and avoid infected people. (Take a look at the this article on how the Black Death came to an end, though it's not scientifically validated)

I don't think that this fits your question, but a zombie virus might be a workaround for that problem (the atheist in me says that if God does exist, zombies might as well) ...

Natural Disaster

Natural disasters like climate change, floods, asteroids and such are in my opinion the surest way to kill all humans. Depending on what disaster you choose and how good you plan you might kill all of mankind in one single day (imagine 2012 if nobody had had a clue about what was going on) or at least get a good part of the job done. However, your means of invoking something like that are very limited (which might be the reason we call them natural disasters). I think one way would be to enforce an ideology that advances the exploitation of natural resources, which will eventually lead to said disasters (we've all seen An Inconvenient Truth, haven't we?). However, this would take more than one lifetime and is kinda hard to execute as well.

World war / Nuclear war

"I do not know how the Third World War will be fought, but I can tell you what they will use in the Fourth — rocks!" (Albert Einstein, probably) ... which would be unfortunate, since that would mean that there were still people around to wage world war IV. However, inducing a worldwide open war would promise a maximum of destruction and death amongst humans. This could as well be approached by means of ideology (or religion, respectively) and deceit. But the person behind should not be some Russian guy trying to punish the West for ... being evil, I guess. Because this story has been told in, like, 10 Call of Duty games or so. So far.

All in all, there is no foolproof way to eradicate mankind ... which is a good thing, I guess. Maybe you could combine the methods mentioned above, or consider using fantasy or sci-fi elements (like magic or large-scale destruction weapons). After all, I hope you're asking for a story and not because you're actually seeking advice on how to kill us all °ω°

Be glad doing so isn't easy, because if it was easy, someone would have done it already.

Perhaps the best sure-fire way to kill every human might be to...

• Build a multi-billion or multi-trillion dollar fortune
• Invest heavily in space exploration
• Found a colony the Moon
• Build a huge mass driver capable of launching massive chunks of rock
• Pummel earth until tender.

It may take a while, because humans can be scrappy, but eventually you should be able to get them all. Especially if you wreck the eco-system enough. Oh, and don't forget to take out those pesky stragglers in orbit.

• I've got a way to upgrade that in 5 steps: 1.) Plant a small black hole right in front of the moon's orbit. 2.) Let the black hole evaporate. The Hawking radiation it emits might be enough to crack the moon into a bunch of smaller pieces. 3.) As "mini-moons" drift apart", watch as the change in tides on Earth cause tsunamis, earthquakes, and massive volcanic eruptions globally. 4.) Attach motors to de-orbit the mini moons once they're far apart from each other. 5.) Rain hellfire on them with rocks the size of continents. – Mattias Jul 21 '18 at 6:58

Extreme Climate Change

And by extreme I mean really extreme. Move the earth either much closer to, or much further away from, the sun. Moving it further away, much further away has been tried, but all current analyses indicate that at least some people will survive.

However moving the earth closer to the sun is pretty final. Once you reach the point where the rock is melting it's hard to imagine a technology that will overcome that. And of course if you get close enough the rock will boil. You would have to do this quickly to prevent the traditional last-chance interstellar spaceship.

• If the technology (and immense source of energy) exists to move the Earth close enough to the Sun that the rocks are melting (especially if you want to do it "quickly"), it's not inconceivable that the technology exists to build a shield around the earth to protect it. For example, bringing in a constant stream of asteroids between the Sun and the Earth to shade the Earth might do it. – Johnny Nov 25 '14 at 1:35
• Good point. I sense a game of intergalactic bar billiards coming on. – DJClayworth Nov 25 '14 at 3:00

The best way is voluntary. Provide 100% effective birth control and widespread abortion. Create robots, virtual reality that replicates what people enjoy in others, so no one seeks out real human companionship. Encourage people to be too lazy to put up with the difficulties of caring for children, and the difficulties of life in general. Make it easy, painless and pleasurable to commit suicide. Make simulated murder and violence favorite past times, transition slowly to the real thing while maintaining everyone's participation. Get everyone to group into cities where their every need is taken care of, and their fate is in the hands of the city, so as eliminate solitary holdouts. Persuade them that there is no other world but this one, and that death is not to be feared since they won't exist after death.

Then stand back and watch as humanity destroys itself.

• Sounds like we are already working hard at it... – kutschkem Nov 25 '14 at 12:35
• Have you read 'Brave New World' by any chance? – Rand al'Thor Dec 21 '14 at 21:28
• This is the creepiest answer, as we move this way. – Mnementh Jun 12 '15 at 15:08

I do not have the rep to upvote Twelfth's answer a gazillion times, or I would have done so.
Anyway,yes.
The way I see it, the best way to ensure destruction of the human race is to include all of the following factors (they will follow at a later time), and then have patience. Ofcourse, one must take into account that if you want to destroy the entire human race, you have to also destroy yourself. That comes later.
Taking cues from the extinction of animal species so far, the method seems to be this:

1. Most animals that become extinct have evolved in ecologies that cater to their every comfort, therefore ensuring that natural selection plays a small role. Since the human race is moving in the direction of plush, comfortable lives anyway, I assume this shouldn't be a very big hurdle. Though, just to be sure, you could start a philanthropic trust (I assume you have money) which provides isolated, all-in-one condos to the less fortunate.
In addition, make sure to design and dispatch robots that cater to our every need so that we don't have to do anything. Laziness takes over the best of us, eventually. Also, multiple studies on the subject have shown that when people are not responsible for themselves, or when they do nothing that shows them tangible outcomes of their work, they go into depression. And everyone knows that a depressed enemy is easier to kill.
2. Introduce a ruthless and more cunning predator than we could ever be into the ecosystem. For poetic reasons, this could be the robots - our previous caregivers now descended upon us like fallen angels of heaven. Be sure that they do this not for practical reasons such as food, habitation or protection of territory. There must be an element of sport. Competition is for Killers.
3. Your task is now half done. Introduce natural disasters on a mass scale, affecting areas with the most population densities. Make sure it does irreparable damage to human habitation. This should make the clean-up easier. The robots can help with the 'irreparable' part (but they must never find out that you are one of us).
4. Wait. Then, when the time is right, shoot yourself.
RESIST THE URGE TO TELL THE HUMANS OF THIS MASTERPLAN OR IT CAN ONLY LEAD TO YOUR DOWNFALL.

That's all.

Create a perfect birth control method,... then make it infectious.

• Somebody would be immune. – Loren Pechtel Nov 24 '14 at 21:06
• Hi, Henry. Welcome to Worldbuilding! You might be on the right track here, but we need more detail in answers. Is there anything you can elaborate on? – HDE 226868 Nov 24 '14 at 21:53
• An engineered virus which causes sterility in both sexes. Perhaps it should also produce pheromones in its victims to assist it in spreading. As for those who would naturally be immune, or to avoid some pesky scientist creating a cure, make phase 2 of the virus induce homicidal rage and jealousy. – Henry Taylor Nov 24 '14 at 22:09
• There you go. That could work. – HDE 226868 Nov 24 '14 at 22:18
• @HenryTaylor, go ahead and add the stuff you said in the comment to the answer. – DonyorM Nov 25 '14 at 7:58

Bring down a sufficiently big asteroid. It would be a very slow process but within today's technology--you just need to take along enough bombs (I'm figuring an Orion drive.)

Much lower energy requirements but much slower would be to bring down a sufficiently large comet. You would have to find a suitable candidate in the outer solar system. Things move so slowly out there that it doesn't take much of a nudge but you had better have a very good guidance system as it's going to come in on automatic--you won't live long enough to complete the mission.

• Changing the trajectory of a large asteroid to crash it into a planet is harder than one would expect. Source: Playing lots of Kerbal Space Program :) – Philipp Nov 24 '14 at 23:06
• @Philipp I didn't say it would be easy, only that it would be possible. – Loren Pechtel Nov 26 '14 at 0:28

Just trigger our sun to be a supernova. It will destroy Earth. No one will escape. Not even the ones who are not on Earth. Bonus: all planets in the solar system destroyed as well.

• While that would certainly destroy the planet, he asked for something that he could do, and no human can currently make any significant change to the sun, even if he had all the money in the world. God asked him to destroy humanity, but didn't offer any godly assistance. – Johnny Nov 25 '14 at 2:18

All the possibilities that you need to consider are a subset of https://en.wikipedia.org/wiki/Global_catastrophic_risk

https://en.wikipedia.org/wiki/Grey_Goo or biotech are those that might be plausibly (for a literary work) achieved by a small team or an individual; most others would require either a large scale political event or something not directly caused by humanity.

For something man made, climate change is probably the way to go. Biological weapons just might too, a resistant thing that spreads and mutates before anyone knows what hit them, then the rest die off from like starvation and such in the aftermath. There'd probably be a few survivors though. I'm not sure man made (aside again from perhaps climate change - BTW I would lump asteroid strikes in the same category, as it is the climate change rather than the strike itself that brings on the most pain), but god made things can. Start praying!

For something god made, I'm in favor of a number of solar events:

• A gamma ray burst nails the Earth, wiping out most life. This is theorized as a potential cause of somewhat regular "evolutionary reset buttons" throughout the galaxy. This may happen with very little warning.

• A black hole passing by the solar system could throw off the Earth's orbit and mess things up pretty nasty. This would perhaps be seen coming, as it would pull other stars it passes too and astronomy can track the effects of its gravity.

• Some kind of extraordinary solar storm in the sun might be able to mess up the Earth environment too or irradiate the o-zone and kill us slowly. I'm not sure how scientifically plausible that is.

It isn't really something you could do, but you could always say the end is near every single day until you're right, then take credit for it!

This question reminds me of a game I used to play:

"If you had to change one thing to cause the apocalypse what would it be?"

My favorite was always getting rid of friction. Too many fun ways to die with that one. So maybe pray to god for that?

Or if you have to do it all on your own (prayers didn't do much...), you could break into a biodefense lab and throw a few vials into the wind at each major airport. If you were smart enough you could engineer HIV to be a deadly airborne disease. I'm sure that kills pretty much everybody.

Another approach, not quite so certain:

Engineer a few diseases, airborne and with two phases: The first phase has only mild symptoms, the second is deadly. Perhaps something like aggressively going after the bone marrow. The diseases must be very different so that someone who happens to be immune to one isn't immune to the others. Make sure at least one induces paranoid schizophrenia as a symptom.

Once the diseases are causing considerable damage take credit in the name of major power blocks. This must come with reasonable proof of having done so but you don't need to prove that you really are the power blocks. The objective is to get those paranoids in power to use their military might against the perpetrators.

While it's unlikely you'll get a 100% kill this way you don't need to be perfect--kill enough and the survivors won't be able to recover. You'll want to ensure a minimum of resources are available to them. Incendiary time bombs in as many cities as possible timed to go off in the dry season after things have fallen apart will help.

I would suggest watching the TV Show Utopia to see the most bad ass method to go on this. And probably the strangest one.

I highly recommend watching the show, but not simply reading up what it is about. It's such a good show (that only has 2 seasons, each 6 episodes) and you do not want to get spoiled on anything.

I can't answer the question directly without destroying the show for everyone who is interested, so here is a Spoiler Alert up front!

Spread a highly dangerous and quickly spreading disease. Craft an antidote. Hand it out for free to everyone. People will be thankful. But the disease will be fake. The antidote not. It will just not cure the disease. It will make everyone infertile, (but a few chosen ones - in the show it's a specific race).

• note that this should not be confused with the Fox TV show called Utopia which was cancelled and obviously completely unrelated. – NotMe Nov 24 '14 at 23:53
• This won't kill everyone. It assumes that "everyone" has access to nice things like antidotes. All this will do is leave the poor to inherit the earth! Hey... maybe this is how that happens!!! ;) – GreenAsJade Nov 24 '14 at 23:59
• @GreenAsJade Watch the show. It will prove you wrong. Big time! :) (But your idea is intriguing too) Also: You spoiled it... – kaiser Nov 25 '14 at 0:05
• Interesting - I'm intrigued to know how it's wrong big time, but possibly not intrigued enough to watch the show :) My comment would only be a spoiler if you knew it was a spoiler ;) – GreenAsJade Nov 25 '14 at 0:10

It depends if you're willing to have some amount of copying.

If you are, then do it in a way similar to the Silo series: man creates airborne nano-bots designed to replicate and kill. Unlike Silo, maybe yours could be an accident that they kill everyone (they were only supposed to kill communists or something?)

Knock the Earth off of its orbit. You can do this in many ways (assuming you have very good resources. This will eventually kill everyone.

Here are some ways

Build super powerful rockets and attach them to Earth

Build super powerful rockets and attach them to a large asteroid (bigger than the Earth), and then control it to run it into Earth. This might move the Earth, but also may cause a mass extinction event

or same thing with the rockets

Fly the extremely large asteroid close to Earth. The gravity from the asteroid can knock the Earth of its orbit