# What is the least expensive way to annihilate humanity?

Suppose an evil genius (in 2015) wants to kill as much of humanity as possible. But he's on a budget; despite his years of stealing priceless historical artifacts, and despite having been selected for several excessively over-funded research grants, and despite having rigged AAPL value to shoot sky high in the 90s, he can barely scrape together $1 billion. Sure, he figures, he could always just set off a few H-bombs in some major cities, and hope for maximum carnage. Or, he could plant a dirty bomb in pretty much every decently sized city. But either way there would be a bunch of survivors, and survivors are not something this evil genius wants. Robot minions have been planted in high levels of every major world government, so getting resources that would normally be inaccessible to ordinary citizens isn't a problem, though he'll still have to pay for them. However, these robots don't hold top-level positions (and believe me, he's certainly tried), so he can't make his doomsday project fully government funded. Basically: What is the cheapest (preferably under$1 billion) way to kill off the most people, with only modern technology (no far futuristic stuff, though extension of modern tech trends is fine)?

• Cheap how? Any money left over would be worthless by definition. – Aaru Apr 9 '15 at 0:25
• @Aaru Of course it would...but how will you finance the end of the world in the mean time? You still need money while the economy exists to buy things, because, well, there's still an economy. – The name's Bob. MS Bob. Apr 9 '15 at 0:28
• Related meta discussion: meta.worldbuilding.stackexchange.com/questions/1978/… – Monica Cellio Apr 9 '15 at 3:13
• Great, now we are all on some NSA watchlist. Especially those who followed a few links. Say hi. – Federico Poloni Apr 11 '15 at 19:22
• Time. Just wait 10 billion years and everyone will be dead. It's slow, but it's got a high rate of succes. – Thomas Jacobs Aug 3 '15 at 10:40

My wife has a degree in criminology, and she wrote a paper about how you could poison a huge percentage of the population in a couple days by putting botulism in the milk supply. If I remember correctly, it was something like 2/3 of the population within 2 or 3 days.

If you had something that you could put into municipal water supplies (you are the government after all), you'd be good to go. One disadvantage though is that you have to deal with the fact that it isn't nearly as centralized as milk is, and you'd have to put it into the water after it's treated, not before.

One advantage of using a bio agent over a chemical is that you have a one time ingestion, and then an incubation period. There's no chemical (to my knowledge) that you can ingest once, and then die several days later. You'd at least be ill fairly immediately. Additionally, bioagents are often contagious. That lets you get the pesky people that can't/don't drink milk.

I'll leave the research of various diseases to you, but botulism, anthrax, and maybe some variant of the plague are good starters.

• There's no chemical (to my knowledge) that you can ingest once, and then die several days later. You'd at least be ill fairly immediately. Actually, the strongest known neurotoxin requires several months to take effect, scary stuff: en.wikipedia.org/wiki/Dimethylmercury – Atsby Apr 9 '15 at 8:51
• Get around the issue of having to add your poison before the treatment by putting it in at the treatment plant itself, just like the conspiracy theorists think is really done. – Jon Hanna Apr 9 '15 at 10:29
• You're forgetting that even in the first world, much of the population (including most farms) does not get its water from municipal water supplies, but from domestic wells. So this strategy might be good for reducing urban populations, but the rest of us wouldn't be affected. – jamesqf Apr 9 '15 at 17:57
• @Jacobm001: But even in the first world, there's a significant fraction of the population who avoid milk for various reasons - personal taste, lactose intolerance, strict vegetarianism. Also much of the Asian world uses little milk. And some people still keep cows. – jamesqf Apr 10 '15 at 0:17
• This approach has the right idea but incomplete penetration and acts too quickly. Lactose-intolerant doomsday preppers will survive. More generally I only buy milk once a week, so I can't imagine you'll get everyone. Some people own cows, for instance. Set aside say 95% of your money. Using the initial 5%, build a plant for purifying prions. Put them in the salt. After a year or two, claim that radioactive iodine has gotten into iodized salt, issue a recall of salt. Put prions in the flour. Up the emergency preparedness guidelines for supplies by 50%. Absolutely do not let cows get infected. – Resonating Apr 11 '15 at 21:11

Design a paperclip maximizer. If you are really a genius and can develop such a software, all you need is a computer with an internet connection....

A paperclip maximizer is one of the simplest examples of an AI which would destroy humanity even without a malicious goal. You only have to create an AI capable of self-improvement, and give it a simple goal like maximizing the number of paperclips in its collection. It doesn't have to have human-like goals or anthropomorphic qualities, it just computes very fast and tries to find the optimal way to increase the number of paperclips. If it makes itself smarter, it will be able to quicker acquire or manufacture paperclips, so it will make itself smarter until it reaches singularity, after which it converts all mass into paperclips.

I have chosen it instead of a classical Skynet-like AI, because the paperclip maximizer doesn't need to have human-like qualities. It would also be completely unstoppable if released. Also, such a scenario is more realistic than the robotic minions capable of infiltrating governments. Designing a robot which is capable of disguising itself as a human (as presented in the question) and therefore require human-level intelligence is harder to do then just designing an AI with human-level intelligence without the fancy anthropomorphism.

• I don't really know what you are proposing here. What is a paperclip mazimizer and what does it have to do with software? I shouldn't need to use google for your answer to make basic sense. Can you include more information? – Mourdos Apr 9 '15 at 10:30
• If you are really a genius and can develop such a software [...] I think writing a strong AI requires a starting intelligence greater than merely "genius". Lots of geniuses have tried building strong AI, without success. – Atsby Apr 9 '15 at 19:58
• While AI have come very far I do not think an investment of 1 000 000 000$into R&D today will give you a genius level AI. – Taemyr Apr 10 '15 at 13:17 • I don't like you. I mean, I'm fine with exterminating the humanity but the paperclip maximizer would convert the whole universe into paperclips, and I don't agree to that. – SF. Apr 10 '15 at 22:51 • This is kind of silly, isn't it? Sure, an ASI with the goal of maximizing paperclips or computing the Riemann Hypothesis might inadvertently wipe out humanity - or it might not. There's no way to predict such an event accurately because a superintelligence is by definition something we can't hope to understand. If your goal is to wipe out humanity, why wouldn't you program that as the actual supergoal as opposed to something incidental like paperclips? – Aaronaught Apr 12 '15 at 18:06 ## Asteroids!! If you have$1 billion, one way to kill a serious number of people is to grab an asteroid and hurl it to Earth.

Hitting land would probably cause an extinction-level event. Hitting water would wipe out almost all coastal population (and would probably trigger an extinction-level event as well). I'm torn on which would kill more people.

Hitting the Earth is a bit tricky especially if the asteroid you picked needed a lot of fuel to de-orbit leaving you little fuel to guide it back towards Earth. I think it's doable within budget. It's certainly doable with current tech if budget is limitless.

## Alternatively: Comets

An alternative is to wait patiently for a close shave fly-by of a very large comet and grab that comet and hurl it to Earth. Just pick one form a table conveniently compiled by NASA:

http://neo.jpl.nasa.gov/risk/

Since the comet is already heading towards Earth, and has non-zero probability of hitting Earth, it would probably cost less fuel to nudge it just so to get it to hit Earth.

Now, lets discuss cost. India managed to send a probe to Mars with 74 million dollars. I believe, so far, that's the cheapest anyone's managed. The Beagle 2 cost the British 120 million. So sending a spacecraft just slightly beyond Mars (or in the case of comets, less than Mars) would definitely be within the realms of a $1 billion budget. ## Advantages One advantage of a kinetic projectile is that it is a pure physical process. You can't develop antibodies or antidotes against an explosion or a tsunami. The other advantage is that it will probably trigger massive changes in the climate. Which in turn will trigger crop failures leading to more death due to starvation. ## Defense / Counter-defense Of course, if you can do this, then world governments can also use similar technology with similar budget to nudge your asteroid/comet so that it doesn't hit Earth. But anything defensive needs to be carried out fairly quickly since the nearer the rock is to Earth, the more fuel you'd need to nudge it out of the way. (BTW: If they decide to nuke it, they'd be doing you a favor by increasing the number of impactors) Here, a simple counter-defense would simply be to misinform. Either infiltrate NASA, ESA etc. and publish misleading statistics that show the rock would not hit Earth or broadcast false news. You can also try to be sneaky. NASA tries to constantly monitor close approaches but every once in a while they only manage to detect the comet mere days from the close approach. That's not enough time to launch any defense. Obviously if you're going this route you shouldn't pick a comet from NASA's list of comets. • The expensive part of this plan would not be getting to the asteroids, but getting the asteroid back to earth. Changing the orbit of something that heave requires HUGE amounts of fuel. – Jens Apr 9 '15 at 12:14 • Would cost a LOT more than$1 billion. See NASA's budget, or what Elon Musk has invested in SpaceX - which still hasn't sent anything beyond low Earth orbits. – jamesqf Apr 9 '15 at 17:59
• @jamesqf: Building a business of launching rockets and renting other people's rockets to launch your spacecraft are two different things. It's not appropriate to compare the cost to NASA's budget. Rather, you should compare it to the Beagle 2 or the Mars Rover (though the Mars Rover did cost 2.4 billion) – slebetman Apr 10 '15 at 2:23
• @slebetman: SpaceX currently advertises $90 million to put 53,000 kg into low Earth orbit: spacex.com/about/capabilities Say an asteroid diversion mission can get by with something the mass of the ISS, approx 450,000 kg. That means 9 launches or$810 million just to get the ship to LEO. Then you need the fuel to get it from LEO to the asteroid, about the same deltaV as to get to LEO in the first place. Now you're over budget, without even considering the cost of the ship itself. – jamesqf Apr 10 '15 at 5:27
• Really, a cheaper option would be to infiltrate the NASA and have them believe one of the comets is heading right at us. They will invest the 100+ billion themselves, and if you mislead them properly, nudge it right in Earths orbit. – Sanchises Apr 12 '15 at 18:10

Wait

Eventually the sun will explode expand into a red giant, taking out most of the solar system with it.

What remnants of humanity that have left the solar system would likely meet the same fate elsewhere, or gradually evolve into something we wouldn't identify as human.

Eventually? Perhaps the heat death of the universe will wipeout what's left

Total cost? Absolutely nothing and you'll never live to regret it

• You beat me to it. As I see it, if you just wait long enough, it will be most likely either an asteroid or super-volcano triggered extinction event that gets humans. If some survive that the expanding sun will get them. If they manage to get out of the solar system the end of the universe will be the final fail-safe. – Tonny Apr 11 '15 at 10:27
• If you wait long enough, but nowhere near astronomical timescales, I reckon that there's a fair chance that some other chap will do all the hard work for you. – Dan Sheppard Apr 12 '15 at 16:20
• I'd call the "end of the universe scenario" a failure on the part of the Evil Genius. He likely won't live long enough to see it, even with a billion dollar investment in extending his lifespan, and he definitely didn't cause it! Judging by the content of the question, I would say that Acceptance Criteria include the Evil Genius surviving, while the rest of humanity fail to survive. In context with these answers, you'd need to explain how the Evil Genius survives the asteroid, supervolcano, exploding sun, or universal heat death, when everyone else doesn't... On a budget of a billion dollars. – Ayelis May 28 '15 at 21:15
• I'd argue that the job wouldn't be complete if the evil genius survived, and my answer hints at the fact that the evil genius dosen't survive. Also, I couldn't resist ;p – Journeyman Geek May 29 '15 at 0:06

Political instability, 2 small nukes and a small number of cheap short range small rockets.

A combination of cheap attacks like some mentioned in other comments, biological in particular but targeted.

Engineer outbreaks of one set of diseases in American cities while poisoning lots of people in Moscow. Just to get the public panic going.

Add a few sniper teams hitting a few random high-ranking politicans on both sides. Try to make it look like tit for tat attacks from the other side to get the politician scared.

Make sure the media start talking up the possibility that the outbreaks and the assassinations are intentional. If you can fire things up enough real politicians will start saying that their side needs to strike back.

Get a few more nuclear powers involved by similar means.

Set off one nuclear device in a major US city, a few minutes later set off the other in a major Russian city.

Launch your rockets within the territory of the US or Russia. Don't worry, they don't have to go high or be loaded with anything, they just have to show up as launches on the other sides radar and surveillance.

I think that would be pretty doable with a billion dollars and government-level access to weapons.

• having a hard time believing this one kills off, for example, Australia and Africa. – msouth Apr 12 '15 at 12:36
• With recently published plans for future NSA policies, part of this might become much cheaper: Make a cyber attack on the USA and make it look like its not too unlikely that it is coming from Russia to provoke miliary action ... – Hagen von Eitzen Apr 12 '15 at 21:17
• @msouth - probably not directly, but once you've got paranoid nations firing at each other, the possibility for collateral damage (especially if both sides start lobbing nukes) goes way up. Countries getting involved as networks of allies, or opportunistically, or trying to get both sides to stop (and getting blasted by both sides, then), maybe a red herring or two if somebody realizes a third party is involved, which can be aimed at innocent countries... – Megha Jun 17 '16 at 2:53
• I think this is absolutely the best you're likely to do for 1b. I do think it's very important to get the rockets going through the air in addition to the actual nuclear blasts, but I would avoid the cities and instead aim for military targets, which would look like a more credible nuclear first strike. Nuclear strategy pretty much dictates that once the opponent has fired nuclear tipped weapons at your nuclear retaliation capacity, you have to hit back with everything you've got while you still can. – guenthmonstr Sep 23 '17 at 3:35

## Biological warfare

Research and development of a highly infectuous and resonably deadly disease seems to be the best "bang for the buck" in this scenario. It does require specialized skills and lots of luck, but (unlike other methods) it scales well, as the same virus or bacteria that would wipe out a single city can also wipe out most of the world, if you can deploy it appropriately, preferably in many countries at once, in mass scale, and it has a long incubation period - where many people would catch the disease long before the first deaths occur.

## Leverage

Another option is to provoke someone else into killing most of the population for you. For example, if you don't have access to the very top officials, still your robot minions could possibly launch a few nukes during some time of random political tension and watch Mutually Assured Destruction happen as the other side simply doesn't believe that it was your fault, and not the 'enemy' government.

• Spend the 1 billion on perfecting a way to deliver ebola to 75% of the world's population in a matter of hours from starting the process. People won't be able to react quickly enough to get the news out, and stragglers will be caught as it passes from person to person. Use follow up methods to despoil surface water sources, electrical generation capacity (for water wells), interrupt fuel (oil, gas production and refinement) and, of course, all the cropland across the surface of the earth. But the key would be biological, the follow up would merely help it spread. – Adam Davis Apr 9 '15 at 19:13
• See Frank Herberts The White Plague how one guy on a budget can pull such a stunt. – Ghanima Apr 10 '15 at 12:03
• Luckily for us, other people have already done the work for us. It probably would not cost more than a few thousand to outfit a small force of individuals to raid some infection disease center and release all of their mutant super diseases. The only research you would need to go is a Google search for the labs with the worst samples. – Jonathon Apr 11 '15 at 19:03
• According to Richard Preston's The Demon in the Freezer (2002), a motivated individual with graduate-level knowledge of virology could weaponize smallpox with a few months of time and roughly 10,000 worth of equipment. All the necessary equipment is routinely used industrially and purchasing it wouldn't arouse much suspicion. The CDC does not keep large stockpiles of vaccine. The hardest part is getting potent smallpox virus from either the CDC or Russian labs. – Robbie Rosati Apr 11 '15 at 21:29 • In the last resort with smallpox, we would revert to the most ancient and unreliable vaccine. Find someone who is recovering and inoculate people with pus from that person's remaining sores. It worked once, could work again. Or is cow pox still out there as a disease of cows? If so, infecting oneself with that is protective against smallpox. – nigel222 May 21 '16 at 16:17 At the risk of getting my name on a list... I would go with a biological attack as well, but rather than sinking loads of time, effort, and money into developing a super virus, I would look into getting my hands on a wide variety viruses. Look into things like: H1N1 Any number Viral hemorrhagic fevers Multi-drug-resistant tuberculosis And so on... So rather than a single wide spread pandemic you have several overlapping pandemics. Dispersal would probably get a little expensive, you'd want to simultaneously strike as many major airports and seats of power as possible (by seats of power I mean parliaments, senates, military bases, and so on...) It would probably also be worthwhile to go after medical establishments (hospitals and large medical conferences). Keep in mind you're not dropping one virus per location you're looking to drop as many as possible on every location. Then if you have any doubts about how effective things are going to be or you really want to add to the heap... Taint basic medical supplies (latex gloves for instance). You don't really need to cause casualties with this. It just creates further panic and gives people a reason to fear and delay treatment. • Look at how Tom Clancy handled this--despite airports being the obvious target they have a lot of security. Instead, go for trade shows. While you have more locals than you have in an airport you still have mostly people from elsewhere who are going to go home and you don't have anything like the security to deal with. You might even be able to combine these by timing it so people are contagious as they are flying home. – Loren Pechtel Apr 10 '15 at 22:12 • Also, skip the hemorrhagic fevers, they aren't contagious enough. You want stuff that's airborne. Given the budget you should be able to make smallpox, if your organization is good enough you might even be able to evolve a vaccine-resistant version. – Loren Pechtel Apr 10 '15 at 22:15 It's really pretty easy. • Buy off the leaders of a political party so that they'll counter clear scientific proof that humans are already doing it to themselves. • Maybe even start a faux news network to support the arguments of that party and to undermine those of the science based opposition. • Pay a few fake scientists to lead your argument. The real news networks have this innate need to show both sides of an argument, thus making it seem like your scienteists are worth listening too, and won't realize they've been playing into your hand until it's way too late. • Wait a few decades for the planet to overheat, the oceans to rise, droughts and the subsequent hunger to start world wide wars. • Enjoy all the spoiling of your efforts. • Australia, which is in the middle of a tectonic plate and is so boringly stable that it doesn't have any self-respecting mountains any more, just hills, once had inland seas connected to the oceans which once were much higher. For that matter the temperature was once much higher. It's not the end of the world, it's the end of civilisation as we know it. It seems to me that high temperatures and water on both sides of the Great Dividing Range would result in a more temperate climate with regular rainfall probably producing more arable land. – Peter Wone Apr 12 '15 at 9:33 • The people in Siberia will think a ten degree rise in average temperature is just marvellous. – Peter Wone Apr 12 '15 at 9:34 • @Peter Wone: Look up the Permian-Triassic event (AKA the Great Dying), and reflect that one of the most plausible explanations for it is extreme global warming caused by massive volcanic eruptions setting fire to large coal deposits: en.wikipedia.org/wiki/Permian–Triassic_extinction_event#Causes_of_the_extinction_event Also consider that photosynthesis shuts down at higher temperatures. – jamesqf Apr 12 '15 at 18:30 • You could just join a conservative political party. This seems to be their current MO. – Agi Hammerthief Apr 12 '15 at 21:49 • @jamesqf - I don't need to look it up, I'm already familiar with it. I have no political alignment. All the political groups are misrepresenting the facts. Nobody knows for certain, not even me. I just think that blaming industry for global trends is like blaming dams for tides. They do exert influence. They don't control. – Peter Wone Apr 13 '15 at 2:27 Start a website where you can ask or answer strange questions. Call it "QueueExchange". People will get too engrossed to remember to breed. End of Humanity in a generation! • Never break the fourth wall!! – Mohd Abdul Mujib Apr 12 '15 at 12:05 • Scientists find link: Website's demise lead to evil genius' excuse, I had nothing better to do, says the lone survivor of WWIII. – Mazura Apr 12 '15 at 22:33 If you're not in a big hurry, then the most thorough and effective answer may already have been posted by jamesqf, but was deleted for only being one sentence long. That is, you could just assist our current extermination plan, which is to kill off life on Earth via climate change, and sabotage attempts to slow down greenhouse gas emissions, stop deforestation, etc. Addition - Further detail for those who don't think climate change likely means extinction: Even in 2012, the International Energy Agency projected +7 Celsius overall by 2100 (effects: highest temperatures in 30 million years, drought on 40% of inhabited land, hundreds of millions of refugees, half of current non-human species extinct) but at some point it seems likely (possibly at +2 degrees, almost certainly at +6 degrees) that this will trigger positive feedback systems (e.g. methane released by thawing polar permafrost) which will generate an unstoppable and even greater rise due to new conditions being created. That leads to +12 degrees, (effects: half of planet uninhabitable due to lethal average temperatures closer to 200 F than 100F). TWO degrees Celsius average increase used to be the effect scientists dreaded, because ecosystems depend on stability, each other, and biodiversity within them to continue to support life in the same way. We depend on those, as without them we will not have food, for example. Then there's clean water supply, and the acts of humans when, say, everyplace at the latitude of India is uninhabitable. Depending on the nature of our evil genius, the chaotic side-effects and decades of suffering as humans face their self-induced demise may be quite satisfying - the main problem may be that he was only a drop in the bucket, and not the root cause himself. (Source and easily-digested summary: https://youtu.be/A7ktYbVwr90?list=PLe9ZM0hR2yCEl_1jYd5HqJkA5oajaeQz6) The thing is, those are already being done by other larger wealthier evil organizations than your own, so your1 billion contribution isn't much help. Perhaps you mean to out-do them and do so faster. Or maybe your goal is to kill just the humans so fluffy animals can survive global climate change.

The ideas to contaminate the food and water supplies with diseases and biological warfare agents are good, but they might be survivable by some, and if you want to kill the fluffy animals too, it might backfire since if you killed 90% of the humans, it might set back their greenhouse emissions and avert a climate change extinction.

Another idea: Infiltrate Monsanto and/or Syngentia, the GMO food companies, and alter their seed projects so that seed crops are planted with cross-pollenating, species-hopping pollen which when planted on every continent, will result in all plants becoming poisonous, and/or all food crops becoming inedible, toxic, and/or infertile. Then you just need to destroy the world seed archive in Norway. Of course, this also falls under "larger wealthier evil organizations are already doing it".

The asteroid idea is good (could be 100% effective), though you don't have the money for it... though with your robot spies, you might be able to find a near-miss asteroid, fake the data to show it's going to hit Earth and needs to be diverted, so the world governments can be conned into launching a mission which can change the asteroid's course, which you also hijack and/or divert with false data to get it to hit the Earth after all.

• Tricking governments into building you a world-destroying spaceship? Priceless. – Paul Chernoch Apr 9 '15 at 20:15
• @PaulChernoch Yes, it has the bonus perk of making your victims feel very stupid right before they get wiped out by their own space technology. :-) – Dronz Apr 9 '15 at 20:34
• But the true evil genius has a backup plan to stop the ship before it destroys the world (framing someone else), winning a Nobel Prize, getting put in charge of World space security, after which point he gets a much bigger budget to play with. – Paul Chernoch Apr 9 '15 at 20:48
• @Aaronaught Edited answer above: Citation and details provided in new second paragraph. It's not that we will be dead by 2050, but we may be doomed, which may even be preferred, depending on the sadistic tastes of our evil genius. The likelihood is also quite certain, unless we take drastic unprecedented action as soon as possible, and maybe even if we do. – Dronz Apr 12 '15 at 19:53
• @Aaronaught: People can't survive on the ISS for very long without regular resupply missions to provide food, water, and air. See e.g. space.stackexchange.com/questions/2014/… – jamesqf May 28 '15 at 18:28

"Delayed trigger" biological warfare.

Instead of trying to infect as many as possible really fast (and still missing all isolated populations) aim at prolonged spread phase with delayed attack phase.

We have a whole lot of different "harmless diseases" in us, and nobody bothers curing these. For example, tuberculosis which is dangerous to cats is carried by a large segment of human population with no visible adverse effects.

Developing a disease that, e.g. attacks the ovaries rendering women infertile, or very slowly degrades the brain (taking about a year to reveal itself) - one highly infective but with minimal initial social impact - this would kill the whole humanity before the danger is realized. And I believe a $1bln would be sufficient to fund the research. If you create initial sources of spread of the disease in all 1st world countries, and it is lethal (say, that brain degradation variant) the chance a vaccine would be developed in time is zilch - by the time the disease reveals its effects, only a minor part of world population is not infected, and it will spread to the remaining parts as they can't remain in isolation forever. Meanwhile all scientific centers of the world are "neutralized" first, and while the third world countries and isolated colonies would die off last, they don't have means or resources to develop the vaccine. • Extremely long incubation period would be very effective. Spreading it is laughably easy: Just use the major international tourist centers as starting points. All those tourist-traps in Rome, Paris, London, Pier 39 in SF, Walk of Fame in Hollywood, Times Square in NY, Disneyland, the list is endless. – Tonny Apr 11 '15 at 10:44 Since biological attack has been flogged to death (heh), let me offer a means of attacking at least the first world nations: disrupt the electrical grid. EMP devices or other means of destroying electrical substations where the high voltage transformers are deployed will trigger massive cascade failures, and the grid won't be brought up again for a period of months or even years since there are no spare transformers waiting to be deployed (and the factories that make them are without power. Time this in November and the food and heat rapidly run out, transportation grids are down and soon the population is starving and desperate. Many of the deaths will be caused by looting mobs. The second and third world nations will be rapidly crippled without international trade, and will also feel the effects of shortages, although not to the extent of the First World nations. Without the various international organizations to facilitate trade and diplomacy, you could expect large areas of the second and third worlds to become effectively ungovernable, or fall into war and anarchy. This isn't 100% effective (although almost nothing is, even a bio war attack will have survivors who have immunity or are isolated and not infected), but will reduce the global population by a very large amount. Dr Evil can figure out alternative means of culling the remaining population after the effects of the global grid shut down have passed. • Except that "EMP devices" exist only in fiction, and even if you had an EMP it would do absolutely nothing to a high-voltage transformer. – Atsby Apr 9 '15 at 20:27 • @Atsby EMPs are are released by nuclear bombs. It's just that they also have other effects that render the electromagnetic interference slightly redundant. – KSmarts Apr 9 '15 at 22:01 • Like many other suggestions, the EMP solution only works on urbanized, technology-dependent populations. For many rural populations, all that would happen is that they'd wonder what happened to the satellite TV. Others of us would be inconvenienced, but would probably manage to survive. – jamesqf Apr 10 '15 at 0:27 • EMP devices exist in the here and now, and can also be non nuclear. A huge voltage spike being transmitted through the grid would indeed nail transformers and cause massive cascade failures throughout the grid. Do it across the first world and you generate enough chaos to essentially destroy industrial civilization, which will take out a lot of the rest of the world as well. – Thucydides Apr 10 '15 at 0:57 • You don't need EMP at all. Just write a computer-virus to hack the power-grid control computers and make them self-destruct the grid by overloading/shutting down plants, distribution points, etc. Without power, no telecoms and internet. If you do this wide-scale enough the lack of communications will also seriously hamper any coordinated attempts to get back online. If someone manages to start a power-plant again, you just have the virus bring it back down gain. – Tonny Apr 11 '15 at 10:36 Trigger global thermonuclear war via false-flag nuclear attacks The easy part is launching the nukes. All you need is to take control of one ballistic missile sub. I'd say that should be feasible on a budget of a billion. You might want to go for a Russian Typhoon- or Borei-class boomers. Why Russian? The endemic corruption at the highest levels of Russian military and political life will make cracking their operational security easier, which means more boom for your buck. Even with a billion dollars, it's probably not feasible to bribe an entire sub crew to start WWIII—what good is money when your hometown is a glowing crater?—but it certainly should be possible to bribe one officer to expose the sub to capture by your own forces. Make him think he's betraying the sub into American hands, and make him rich in return. Once you take the sub, you'll likely need to replace the crew with people loyal to you and your goal of ending the world. You'll also need nuclear launch codes. Russia uses a slightly different system than the American one with the famous "football" that accompanies the President everywhere, but even the best systems are prone to human failures of operational security. Corruption can only help you here; humans are always the weakest link in any security system. The hardest part will actually be convincing the other nuclear powers that this is a genuine attack. You need them to believe it's real and not a rogue or they might not retaliate with their own nuclear arsenals. In the event of a nuclear launch, the first thing American, Russian, or Chinese leaders will do is call their counterparts. So you either need to find a way to get them to distrust each other so much that they won't believe Putin when he tells them that someone's taken his sub and the attack is unauthorized, or you need to prevent them from talking. Personally, I'd my best to do both. Putin is pretty untrusted to begin with--another reason to take a Russian sub. Executing your plan when he's flexing his muscles like he did last year in Crimea would increase your odds of success. But you'd probably need to give diplomatic tensions a push or two to really get things boiling. So you'd need to plan and stage an international incident. I'll leave that as an exercise for the reader, at least until I've had time to put more thought into it. I suspect that all you really need to do is make sure someone in the room with the president in those first few critical minutes suggests that "Please don't shoot! Someone has taken over our sub and launched this rogue attack!" is exactly what the Russians would say if they wanted a free shot at nuking the US. Your other target will be global telecommunications. I would go for a combination of DDoS attacks aimed at major internet backbones and coordinated physical attacks on submarine telecom cables near where they come ashore. Bonus points if you make it look like the attacks come from the Russians. There actually aren't that many major submarine cables, and they carry the vast majority of global telecommunications. Attacks on all of the American and Chinese cable landfall sites would be considered an act of war in and of itself by American and Chinese leaders. Disruption in telecommunications and the internet would result in considerable domestic unrest, although I wouldn't give that time to build, as they could use that time to repair the cables. Cables should be destroyed hours at most before launch of nukes. Then you've just got to launch your nukes. Hit all the largest American and Chinese population centers, and throw in the capitals of every other nuclear power except Russia for good measure. Even if the leaders of every single one of those countries decide to die without retaliating, the three Borei-class subs currently in service each carry 16 RSM-56 Bulava SLBMs, which are hardened against missile defenses. Each SLBM carries 10 MIRVs, each with a nominal yield of 100-150 kilotons. So you have 160 nukes at your disposal, each at least five times as powerful as those used on Japan in WWII, with a global reach. By playing with a few cities at NukeMap, I had no trouble managing 300k-500k points, er, estimated fatalities, per MIRV. In population centers with a lot of high-rise buildings and skyscrapers, 800k-1 million fatalities isn't difficult if you optimize for the overpressure wave by airbursting the nuke about 1km off the ground and letting the collapsing buildings do most of the actual killing. Even if the only nukes launched are from your single stolen sub, by targeting all the most populous urban centers, you could likely kill a quarter billion people and precipitate a worldwide societal collapse. Which would in turn kill many, many more. If your false-flag attack succeeds in sparking a full-on nuclear war between Russia and the US or China, the effects will be much, much more complete. • Geez, I somehow missed the "robot minions" part of the question. That makes compromising national security trivial. If you have capability of replacing a human with a robot minion that can pass human detection, then take control of a bunch of nuclear missile subs by replacing their crew. Execute multiple simultaneous false flag attacks against every nuclear power. If several Russian subs launch, and several US subs launch back minutes later, what the presidents say on the phone won't matter—nobody will believe it isn't an earnest attack. Full retaliation and mutual annihilation will follow. – Joshua Hanley May 29 '15 at 13:32 • If you can only get one SLBM sub, I think you're better off aiming for US nuclear retaliation capability, e.g. silos in the middle of nowhere, major naval and air bases, etc. That's much more likely to convince the US to retaliate in kind. Don't overestimate how much the nuclear command structure cares about the civilian casualties from the first round; they are all about the long game. – guenthmonstr Sep 23 '17 at 3:43 Do nothing. The overwhelming probability is that if you wait long enough, humanity will destroy itself or suffer a natural disaster, at which point you will have$1 billion to celebrate and only living expenses ( and whatever defences you put in place to prevent yourself being amongst the dead )

Annihilate humanity. This is an entirely cynical, theoretical think exercise, yes??

The cheapest way is to let humans do it themselves.

Use the minions in two ways: Generate cash and engender kill-games. These processes support one another as long as you invest in the weapon industry. Start and nurture the games worldwide. Have internet databases on how to approach hard kills for more points. Points can be traded for better weapons, but of course never for safety gear. celebrate big scorers so the second echelon goes after them. Every kill should transfer the killee's points to the killer. Infiltrate social media to motivate your growing army of killers.

You'll probably have to kick-start the killing games by murdering a few loved ones yourself, using the minions, but after that the process should be self-propelling.

As murders mount, civilisation will collapse and generate a "better" environment for the games to prosper. The famous 3 meals will be skipped, smart gamers will eschew perfect count and start epidemics and mass poisonings for you. There is a small chance a few warheads will fly as well.

Better have a truly safe place prepared for the game administration and yourself until the last two mega-killers stalk one another at the south pole. That very last human you will have to do yourself. Be careful, do it in a safe way! Any minions left?

• I think this is going to be my next film script... – yobddigi May 23 '16 at 10:03

Nikola Tesla theorised that the Earth has a resonating frequency. Assuming the theory holds true, you could set off a series of relatively minor explosions on the Earth's surface at the correct intervals and energy would gradually build up in the Earth's crust. Eventually the Earth would start vibrating so violently that human life on earth would be unsustainable (perhaps the Earth itself may fall apart).

In my mind this is the cheapest and most efficient way of wiping out humanity. The problem with chemical/bio attacks is delivery and resistance. There will always be people that have their own milk/water supply etc. And you'll find weird cases where some humans are resistant to whatever you try on them.

At present, everyone in (known) humanity shares Earth as a common home, so I think it's better to target the planet instead of the people. Just make sure you take out the ISS first, otherwise a few pesky astronauts may remain.

• The Earth is not homogeneous, it won't work. – vsz Apr 9 '15 at 10:09
• Even if an object has a natural frequency it still has damping due to the energy required to strength and compress. There would be plenty of damping in this case. – Gary Walker Apr 9 '15 at 19:58
• It sounds like a Bond movie. – Peter Wone Apr 12 '15 at 9:27
• Resonant frequency of something with a liquid center and all kinds of mushy in-betweens out to solid...wouldn't it damp out/absorb any of your efforts? – msouth Apr 12 '15 at 12:41

Bio agents in real life suffer from a large number of problems. Some of them have natural immunities floating around the population. The most virulent can burn out a population center incredibly quickly, but would be isolated almost immediately following discovery. Other diseases have a long incubation time, which increases their spread, but run the risk of being rather survivable, and having plenty of time to counteract. Overall, a bio agent is not going to do the job - even if you had top level government access, you'd lose control as soon as you started trying to counteract control efforts.

Assuming robot minions do not take away from the billion dollar budget, then you've infiltrated the wrong things. Take over the media of the major world powers, and then you have real control.

Governments all over the world rely on the will of their people to hold up their actions - anything less will have your robot minions dragged out and shot for treason. But people have a tendency to take sides around issues, and if you control the media, you control the issues - all of them.

Get a few writers in all the major news outlets, and most of the minor ones. Just get them doing their jobs with precision accuracy - feed them intel they aren't supposed to have from your higher level access, and provide unquestionable proof. Control the bad guys too - make them take more risks, stupid risks that are way out of line with a winning strategy. Steep the world in fear and hate and agony.

Pseudo legalize all drugs by making enforcement virtually impossible. Engage in armed conflict at every possible opportunity. Shut down food, water and medicine supplies in as many places as possible. Damage as many resources as possible. Chaos and martial law will ensue whether you could do it yourself or not.

Install and encourage as many suicide cult leaders, militant radicals, poison spewing pundits and murderous mob bosses as you can. Don't just leverage action - force a reaction.

Arise as the only remaining source of viable authority and amass an army - a real human army with an actual mission of attempting to quell the mass chaos. Point them in all the wrong directions, fighting battles they must fight but cannot win. Fight to the last man, for the sake of humanity, God and whatever else you can leverage.

The pitiful remainder of your loyal forces would then be trivial to make disappear one company at a time. Having bent all remaining resources to your will, send out robot death squads to finish the task of wiping out any remaining trace of humanity.

Then party until you die with a robot prostitute or something, I guess. You win.

"Botulism in water supply" is way hand-wavy. Botulism bacteria are anaerobic and won't fare well in water. They are already present in substances like honey which is why infants should not be fed honey: their digestive tract does not have the acidity of an adult and will consequently not kill the bacteria before they start producing botulism toxin.

So putting the bacteria in drinking water or elsewhere will not accomplish much regarding the adult populace. But then you don't need the bacteria but rather their toxin. Using that is, strictly speaking, not as much a "biological" attack rather than a "poison" one: as opposed to biological attacks, the substance does not multiply.

But that is not really necessary: few kilograms are sufficient for poisoning everyone on Earth. The poison is really potent and works by enzymatically destroying nerve endings. Currently, there is one major supplier of Botox, the medically diluted version of this poison, and I think its total poison production so far was less than one gram of active component. I'd expect it to be reasonably straightforward to crank up production.

Spraying Botox is not really all that effective (even though aerosols are quite an effective way of ingestion) since it decomposes rather fast. If it were more tenable, it would have been a warfare component long ago. The water supply would be an obvious choice. However, people might stop considering tap water when seeing its effect.

• botulism bacteria are anaerobic and won't fare well in water... not seeing the link. Why? If they can survive in honey, why not water? I get that diffusion of the glucose in honey would enable longer survival, but they would still be able to survive for a while in water. Long enough. – ArtOfCode Apr 9 '15 at 11:48

Iocane Powder VX Gas:

It is odorless and tasteless, and can be distributed as a liquid, either pure or as a mixture with a polymer in the form of thickened agent, or as an aerosol.

How many grams of VX can I get with a billion bucks? If that's not enough then use the money to lobby for the contract. Now they pay you to 'dispose' of it.

Botulinum may be more toxic but it doesn't exist in weaponize-able quantities.

But either of these (and most of the 'solutions' here) would still leave me us with at least some survivors, just like every other poison. Indeed, even nuking the site from orbit isn't a one-and-done.

A better solution would leave the Earth uninhabitable for the foreseeable future. Here's one way: (that may go over budget, but you get what you pay for. And I was contracted to "annihilate humanity" so, ante-up!)

• Buy an international trucking company
• Have one robot working in 'sales' at every factory on the planet that produces CFCs
• Do [...stuff] that:
• Destroys the ozone layer
• Estimated time frame of goal realization: < 1 century
• profit?

Most scientists are agreed that without the earth’s ozone layer, we would all cease to exist. -ozonedepletion.co.uk

Interestingly there is actual data available on the effects of biological control agents across multiple generations. Australia methodically and repeatedly deployed viruses on a continental scale in a deliberate effort to annihilate an enemy (rabbits) and conducted studies of the spread of disease and the distribution of remnant populations as well as the rate of recovery and development of resistance.

Wikipedia is a good place to get an overview http://en.wikipedia.org/wiki/Myxomatosis

Of particular interest is the fact that remnant populations develop resistance and only fifty years later rabbit mortality is down from 90% to 50% of infections.

Humans are much more mobile. I think for once Hollywood has the truth of it, and panicked idiots are very likely to greatly exacerbate the spread. In Australia geographic isolation preserved reservoir rabbit populations. Sick rabbits stay where they are and just die, but sick humans will run straight for uncontaminated population centres. And misguided fools will dribble about compassion and let them in.

I suppose this does provide a way to divest oneself of snivelling lefties, which are arguably the other main threat to long term survival.

Nevertheless it is a certainty that there will be remnant populations. They are likely to be reduced to a very low level of technology, and will be little more than very smart bald apes.

Would there be a reboot? Even our simpler current tech has elaborate dependencies on other tech for materials, construction and maintenance. The level of specialisation means you'd need a very large skillbase to rebuild. A slow decline over two or three generations is more likely.

It is, however, not out of the question. My neighbour is a mad keen mediaeval re-enactor. He doesn't just know how to wear half a dozen types of armour, he knows how to make them. And repair them, of course. It never ceases to amaze me the things he can make from materials not far removed from nature, and he's an accomplished bowman - which is just plain astonishing for someone who likes to stay inside painting figurines.

A computer/internet answer that requires no innovation: connect with like-minded crazies around the world to start forest fires absolutely everywhere. A good meme could see that no two adjacent trees are left uncharred within a couple months. There's even a Dead Kennedys song to help you along.

Society simply couldn't respond in time. You can see how we fight wildfires for weeks at a time already. If a large enough cadre of wankers were actively setting as many forest fires as they felt they could get away with (though many people setting fires get caught, the investigations often take days or weeks by which time the damage will be done, so long-term security from arrest is not necessary), society would lose that battle and fast. Of course, completing the human project of deforestation would hasten ecosystem collapse. It would also remove a major source of negative carbon from our planet, and the fires themselves would put serious CO2 poundage into the atmosphere. There are an estimated 3 trillion+ trees on the planet as of last year. My chemistry's a little weak and my google's not great tonight either, so I'm having trouble figuring whether burning all the trees on Earth would consume enough of the atmospheric oxygen to potentially asphyxiate us all, but it's possible (desert and island dwellers will have the best chance to avoid asphyxiation if it's even a remote threat). There'll be excess carbon monoxide and other toxic crap at the party to help with the asphyxiation, since forest fires aren't going to give you 100% clean "chemically complete" combustion. Then, there's the ash to contend with. With really tight coordination, you could have every forest on earth burning at the same time, blacking out the skies planetwide like a supervolcano went off. That's going to have a serious negative effect on ocean algae (which likes sunlight), which is of course our last remaining major photosynthesizer in this scenario, meaning it will take a long time to get rid of that CO2 and to get our oxygen back.

Cost: practically free. An internet connection, a can of gasoline and a book of matches. Yes, the oldest weapons are still the best. Thanks a lot, Prometheus.

• And corn fields could be targeted as well. – Donald Hobson May 22 '16 at 13:37
• Yeah, once your villains have chosen fire as their weapon targets present themselves endlessly. Forests and cornfields are low security targets but for any guarded target all you need is one nihilistic employee whose girlfriend dumped him lately or never existed in the first place and kablooey! Combusting all the trees might not burn up enough O2 to asphyxiate everyone, but combusting everything combustible might. – SudoSedWinifred May 23 '16 at 0:22

Design a self replicating robot that consumes natural resources.

Picture a machine that can convert wood and straw into plastic and carbon nanotube conductors and piezoelectric actuators and thin film printed semiconductors and all sorts of other good stuff using just wood and straw as raw materials and power source. Drop a few in every forest in the world and wait. Unless they are all hunted down before the exponential growth gets too big that will be the end for humanity.

Long live RepRap and organically powered scout robots.

Remember when people stop looking after nuclear plants they overheat or meltdown and cause radiation leaks, weapons stockpiles also need TLC. Also remember the people in disaster shelters and nuclear submarines will be around for a couple of years even if the rest of the planet falls apart.

Genghis Khan and his armies killed a third of the population of Europe (and millions of his own people) by weaponizing the Black Death, and that was in the Middle Ages. Although modern sanitation and medical care make this less practical, the right disease could still be made to do terrible damage, and probably do so relatively cheaply.

Seven gigaton-range nuclear weapons (if you find you can't build one that big you simply use the weapon you can build as the trigger for another fusion stage. H-bombs work just as well as a-bombs at triggering h-bombs) mounted on rockets that can lift them 100 miles up.

I'm figuring bombs over North America, Europe, west Asia, east Asia, South America, Africa and Australia.

They'll cause devastating EMP damage and light fires out to the horizon (and from 100 miles up the horizon is very far indeed.) The power grid goes down and society will have collapsed long before replacement parts could be built. (The parts are custom, they aren't just sitting around to be installed.) There will be truly massive wildfires that will burn a lot of cities also.

While the bombs will cause few direct casualties the collapse of the infrastructure will be absolutely devastating. The world will go from supporting 7 billion to supporting some tens of millions at the most--and all those extra people won't simply die peacefully.

Budget permitting do this after the bio attacks mentioned in various messages.

Let's address Aaru's very good point that left over money is worthless, and think just about the cost of getting the scheme to "tipping point" where there is no going back.

What we need is a way to destroy the world profitably.

Burn down rainforests to use them as grazing grounds for fast food chain meat animals.

Extract and sell a popular but catastrophically environmentally damaging fuel.

...yes, these things are happening anyway. (Fossil fuels, in case you were wondering - exactly how much can we burn before we cause a run-away greenhouse effect... or has that already happened?)

To get people to accept this, your strategy should be "sell out your children". Everyone should feel like they benefit... in the short to medium term.

You want a significant portion of the world population to assist you willingly, and give you their money.

Suppose you could double people's lifespans... at great environmental cost? Then a significant number of people will want your treatment, will pay for it, and will DEMAND that you damage the environment to treat them. They deserve the treatment at any cost if anyone else was already getting it.

Some people will oppose your plan, with a slightly longer term point of view... but those people will be outnumbered by the people who have had the treatment, and the children of those who have had the treatment. And can they prevent the world from getting to tipping point?

...Of course, again, if you compare human lifespans and environmental damage now and 2000 years ago, you could say this has already happened.

For $1 billion you could not annihilate the entire human population. My own concept is interrupting the food supply (by interrupting the fuel supply, by probably interrupting the power supply, by probably using EMPs high in the atmosphere). This would lead to widespread chaos, destruction, and death but huge numbers of people would survive. The same is true of 1. bombs 2. poison 3. germs 4. environment 5. etc. With each of these approaches, you may succeed in causing mass deaths or possibly ending civilization itself, but huge numbers (millions or billions) of people will always survive any of these. To ensure the extinction of the human race, you need something really big. The 6 mile wide dinosaur killer would not be big enough to ensure extinction. My guess is something with$ 10 \times $the energy (which equates to a 20 mile diameter asteroid of the same density and velocity - e.g. Phobos) would probably do the job. You won't be able to move this with$1 billion. If using a main belt asteroid or Phobos, this will likely take >100 years to pull off.

The human mouth has a lot of symbiotic bacteria, create several strains that are transmitted by kissing and when introduced to either the male or female reproductive organ result in infertility.

• I don't know if this is going to destroy humanity or not, but I've heard worse pickup lines... – akaioi Sep 6 '17 at 15:00

There's no way you can kill absolutely everyone for just one billion dollars. We are far too spread out, eat much too varied diets, and live in nearly every climate on Earth. Nothing you can do with that amount of money could kill everyone. To do that you'd need to make the entire planet uninhabitable.

The most you could accomplish is a few billion deaths over the course of about a century, via climate change. You'd do it by funding politicians who don't believe climate change is real or who don't care. Maybe even pay them directly to institute policies that will exacerbate it.

Current estimates for how deadly climate change will be vary pretty wildly, but I think it's safe to say it will be much more deadly than even the highest estimates if China, the US, and India all decided to actively make it worse.

One: Create an internet virus. Use stuxnet as a template.

Two: Raid every Westerner's facebook account and autogenerate a photo of them burning a certain holy book.

Three: fill the email inboxes of everyone living in the middle east, Indonesia, Pakistan and parts of London and France with those photos, complete with the name and home address of the "sender".

Four: Hide until the holy war is over.

On second thought, skip steps one through three. Someone already took care of that.

• Funny but not quite there... – yobddigi May 23 '16 at 9:52

Disclaimer: This answer contains sensitive material and material that may hurt or offend some people. If your feelings get hurt, please, drop a comment and I'll see what I can do. The intention here isn't to offend anyone in any way.

Since most attacks generally start in the U.S.A lets start by.... WRONG! Lets start with China!
It is really cheap to make Gutter Oil, and we can make it cheaper.
Decriminalize the production of that oil, and make it mandatory to be consumed.

According to wikipedia, this is very toxic!

Export the oil to Japan and Korea.

Now, send false information to both Koreas and make them fight eachother.
That would be a really bloody war!

But war is great!
You can buy the companies who make both the weapons and the medical equipment to treat them.
You can infect them with HIV and, once again, distribute placebo to them and let them die.

To fire up the war a little more, you can fake terrorist attacks on Russia, U.S.A and multiple parts of Europe (Germany and U.K. would be good places, right?)

This means more money since people will have to buy your bullets, guns and medicines.

If timed properly, you can climb yourself to be the President of the United states of America.
Once on top, you can bride them and change the laws to allow more than 2 guns per week for each person to buy.
You start a campain about gun safety to kids and hand them 9mm.
Send subliminar messages saying that life is like a videogame: that you die and respawn.
Kids shooting their parents everywhere!
Worst yet when the minimum age to buy alcohol lowers to 7 years old.

Since we are in a killing mood, allow untreated water or partially untreated water to go to people's homes.
Since you are on top of the economy, you can say that this measurement is to save some money.
Make it a law to underload the treatment centrals.
Just watch the quality of life, in general, to go down.

Now, send every single person who's 13 and up to war.
Send them in small batches, so they all die.
Use the media to deceive the U.S.A. and tell them that Europe is fighting Korea and pretend you are defending them.
Butcher them all down!
Kids and everyone on war!
The survivors would have a huge suicide rate which would help a lot.

Now, the economy falls down. Block all the importations and export everything.
Hunger and some deseases will kill a lot of people on the way.
Freeze everybody's salaries.
Mutins and Looting everywhere, with rebels setting fire to everything.
From here on, I think the destruction is self-sustained.

Nuclear accidents, sattelites falling down, people dying everywhere, no clean water, no food and a complete lack of protection!

This is how I would do if I were to destroy the world.

• No good. The survivors will descend to medieval level, and rebuild eventually. – vsz Apr 9 '15 at 10:10
• @vsz If there are survivors... And you got to be a VERY lucky guy! The only ones that may survive without any luck are the ones in the middle of the jungle. – Ismael Miguel Apr 9 '15 at 10:58
• Care to explain the downvotes? – Ismael Miguel Apr 13 '15 at 8:04