End of the World Scenario Collection
When I was 15, I thought the end of the world meant losing my headphones but as I read more it turns out a lot of people have thought this through to a greater extent than I had.
“Ladies and gentlemen, the Universe as we know it has now been in existence for over one hundred and seventy thousand million billion years and will be ending in a little over half an hour. So, welcome one and all to Milliways, the Restaurant at the End of the Universe!” (Max Quordlepleen).
An interesting and little known fact is that before Douglas Adams had the idea of the Hitch-Hiker’s Guide to the Galaxy (1978), which began with the destruction of planet Earth, he had another idea for a television series which he pitched to the BBC… and they rejected. The idea was this: ‘The Ends of the Earth’, six shows, each of which would deal with the destruction of the Earth for a completely different reason. The core cast of actors and characters would be the same, a group of scientists in a high-altitude laboratory observation point located somewhere in the Himalayas. They would provide the human reaction to events unfolding below them, the end times, then the whole thing would re-set as if nothing happened for next week’s episode.
This is really just a creative exercise, challenging your imagination to come up with any threat to us which has not been thought of already. Some of these can be mitigated against, so perhaps at least some life makes it (tardigrades, cockroaches or nematodes, people who happen to own bunkers or arks perhaps). Another difference is whether you define an apocalyptic threat as being to the planet and all living things, i.e. all 10 million species die, or just to homo sapiens. Losing the dinosaurs wasn’t the end of everything, so losing your headphones or your own species wouldn’t be either. Just be a change of user.
Where should we look for additional dangers? Well, firstly think about what we need for our survival (water, somewhere to exist, ambient temperature range, the physical laws of the Universe, time, survivable gravity, low radiation, plants, sanity and more). Try to add something new to the list, then why not propose an action that could be taken to prevent it? e.g. too much carbon dioxide — plant a billion trees. I’ll add the main ones in no particular order, to open the conversation.
1. Asteroids.
This has already happened many times over (Yucatan Peninsula, Chi’ing-yang 1490, Russia 1908 & Tunguska 1947) and will happen again, so it earns a longer description. The Chinese strike killed 10,000 people but meteors have (in the past) usually missed heavily human-populated areas or burst in the atmosphere. An air or ground burst depends on trajectory and also on their rock/metal/ice composition. About once every quarter of a million years a meteor measuring half a mile or wider hits the surface of this planet. A five mile-wide asteroid would be the end of almost all life on Earth. There are 100,000 asteroids with at least a 50 mile diameter in the Kuiper Belt, any one of which could be bumped inward to start a long journey toward the Sun that may eventually intersect with our planet’s elliptical orbit — and this redirection toward us may have already happened. Our orbital speed around the sun is about 67,000 mph. Then there also interstellar asteroids like Oumuamua which was clocked at 196,229 mph when it passed the sun. The thing about asteroids is, they are hard to detect because they stay completely dark until they either enter the solar wind and ice plumes behind them or until they enter the atmosphere and light up, in which case it’s way too late.
2. The Sun expands.
“Beginning around 5 billion years from now, the Sun will expand, becoming a swollen star called a red giant. By 7.5 billion years in the future, its surface will be past where Earth’s orbit is now. So the expanding Sun will engulf, and destroy, the Earth.” (BBC).
3. Coronal mass ejections.
If powerful enough and if directed straight at us, a solar flare could remove Earth’s magnetosphere (which protects us from solar radiation) and atmosphere. Superflares (Schaefer) are believed to be millions of times more powerful than regular solar flares.
4. Decrease in ‘sun spots’/solar activity.
“Decline in solar activity has contributed to 17 of the 19 major cold episodes on Earth in the last 10,000 years” (Baliunas). This decline is both good and a threat for us. Reduced solar activity is great for the ozone layer and could help to counteract climate change. If it drops right down though, life on Earth could freeze.
5. Global warming.
This presents a basket of dangers from cosmic radiation to flooding and land-loss, acidification of oceans, cyclones and epic weather (weather is different to climate), together with the loss of species who are too slow in adapting when the parameters of their niche ecologies change. We are currently in a mass extinction; just check the IUCN CITES Red List (1965–2019 record) for amphibians and large mammals. Niches are slipping away and we are in a mass extinction now, with CITES concluding in 2019 that 40% of Earth’s amphibians, 34% of conifers, 33% of reef building corals, 25% of mammals and 14% of birds are at risk of extinction. Large mammals are at immediate risk. Imagine, what would koalas eat if there were no more eucalyptus trees? One example of adaptation is the polar bear which, suddenly unable to find fixed ice platforms from which to hunt and feed itself, has migrated to the mainland and interbred with grizzly bears to live off river fish instead. A warmer planet also favours crop diseases and tropical problems move north and south. Parasite numbers are also higher when cold winters don’t kill them anymore. Warm air expands but warm ice contracts and cracks, so it’s not just sea-level rise but also icebergs in the shipping lanes and vents of warm air creating cyclones (see Rendezvous with Rama by Arthur C. Clark, 1971, for a prediction of this). Water vapour is also a greenhouse contributor, which accelerates the process and puts more water vapour (more cyclones and rainfall) into the system. With a more rapid water-cycle, rocks are broken down faster, which in turn releases more carbon dioxide. A runaway greenhouse effect would move Earth in the direction of the climate of Venus (900 degrees F.).
6. The loss of insects.
We’ve lost rather a lot of bees in the last decade, haven’t we? “Huge global extinction risk for insects could be worse than we thought. Over 40 per cent of insect species could go extinct in the next few decades, with butterflies, bees and dung beetles most affected.” (New Scientist, 2019). Without insects, crops cannot realistically be pollenated fast enough, e.g. by hand, so all animal life which relies on plants and herbivores in the food chain quickly dies of starvation. One possible solution for this would be to pollenate crops by targeted nanobots, but that would mean the accidental ingestion of active robots will become a regular occurrence — and they might dig their way toward sunlight.
7. End of the Ecosystem.
We can’t calculate all of the knock-on effects of removing components of the ecosystem because the variables are too complicated. For example, do we really need the wasp? Seventy years ago, the Chinese leader decided to organise the population to kill as many birds as possible because birds eat cereals/seeds. The net result was that worms and caterpillars (usually eaten by birds) reduced the crops to such an extent that they caused a national starvation event. We just don’t know what all the secondary and tertiary effects of losing a species might be. What would happen if global warming either led to the total removal of plankton or caused it to bloom and release toxins in all bodies of standing water? We may need biodiversity for our own survival.
8. Reversal of Earth’s magnetic field.
The most recent occasion when the Earth’s magnetic field reduced and then the poles changed places was around 780,000 years ago, as shown in the rock record (when igneous molten rock solidifies, it preserves within itself the direction of the magnetic field at the time it set). In the past hundred and twenty years, the strength of Earth’s magnetic field has reduced 6% and the location of the North Pole has rapidly swerved from Canada toward Siberia https://www.forbes.com/sites/trevornace/2019/02/05/earths-magnetic-north-pole-has-officially-moved/#26feefb86862 . The dangerous time is when the flux reduces to almost nothing (about to flip) because the magnetosphere will be switched off and Earth would be bathed in cosmic radiation. Plants die, animals die, reboot.
9. Gamma-ray bursts.
Gamma bursts have been observed but were very distant from us, probably caused by the merging of two collapsed stars, but they did release incredible amounts of energy, c. 10 quadrillion (1,0000000000000000) times the sun’s output. Collapsed stars are also very hard to detect at an astronomical distance but if an event of this kind happened any nearer than 1,000 light-years away, the radiation would bake the atmosphere and ultraviolet rays would then pass through without filtering, causing all plants and plankton to die, followed by everything that relies on plants for food and oxygen.
10. Super volcanoes.
One theory (plenty of basalt in the rock record) about the loss of the dinosaurs was that 65 million years ago, a super volcano erupted in what is now India. 250,000 cubic miles of lava, sulfuric gasses, unbearable acid rain, huge CO2 release — a greenhouse gas so no ozone layer. The Permian-Triassic extinction, the most thorough extinction ever, was also attributed to volcanism in Siberia. A mega-eruption built the Columbia River plateau 17 million years ago. Supervolcanoes are not a thing of the past because you can see one today at Yellowstone in Wyoming. The previous significant eruptions at this site were 2.1 million, 1.3 million and 630,000 years ago, which suggests we could see another at any time. If that happened, we can expect a nuclear winter and acid rain leading to loss of plants, leading to loss of animal species, with the carbon dioxide ppm count rising all the time. The increase in CO2 should help plants grow (if seeds survive), if what’s left of the ozone layer stops enough cosmic radiation to allow this, but the animal kingdom might be extinct by then. Yes, humans are animals.
11. Black holes.
If a black hole were moving toward Earth, the orbits of the outer planets would start to change, so at least we’d know. By measuring the difference between the predicted path and observed path of a planet, the mass and location of the incoming black hole could be calculated. If it came too close, we’d pass into its event horizon and cease to exist. If it passed farther away, another planet could be drawn out of orbit and into Earth’s orbital path, slap, or the careful counterbalance of the Solar System could be upset, influencing Earth to move either closer to the sun or away from the sun and into the absolute zero expanses of deep space.
12. Phase transition.
According to the standard cosmological model, just after the Big Bang, space was full of energy, technically “a false vacuum”. Then, a different type of (more stable) vacuum popped into existence within it, released unimaginable energy and expanded the cosmos at the speed of light, swapping the laws of physics with the ones we know today with the passing of the interface. The energy blast would smash all matter into its component molecules, which would cool and coalesce into new arrangements behind it. This has only happened once since the Big Bang but, theoretically, if an even more stable kind of vacuum popped into existence anywhere in the Universe, it would expand and do the same thing. Travelling at the speed of light, it would arrive before we could see it coming.
13. Epidemics.
Until now, we have co-existed with our pathogens. It’s like an arms race, where the virus (or bacteria) finds a way to disrupt the body of the host, killing the defenceless designs, but it can’t be too successful or kill too fast because there (a) there would be no time to be passed on to another host and (b) there would soon be no hosts left, condemning the virus to become extinct too. Therefore, the most successful viruses are channelled toward being medium-effective. Then, the most resistant designs of host are selected in favour of, which means the most easily overcome and most aggressive virus designs (extremes) perish — but the most effective medium range survive, then the cycle repeats. That’s natural selection. Both sides have a hard time but both survive in suitable numbers — and the struggle drives adaptive evolution for all. However, what would happen if we had a very large space station or a Mars colony? The arms race of epidemiology would continue in one closed system and not the other, for decades. After a significant gap, a powerful virus (which has previously been pitted against an equivalent immune system in a host) would suddenly be freed into a population of hosts who have not been exposed to it (not matched it step by step until it reached this point). This would be a pointy-sticks vs tanks scenario, where humans in that ecosystem would go extinct, then the too-successful virus would follow.
14. Biological technology, genetic engineering, gene splicing and synthetic genes.
Success and failure of biotech are both threats, the common factor being unintended consequences. Some life would survive, but that wouldn’t necessarily be our species. There is an incentive to edit species to become more drought-resistant or produce tastier fruit. Some parents would prefer to edit the genetics they pass to their offspring to snip out inherited conditions they’ve had to endure, or for cosmetic reasons to make them more attractive or clever. However, once these changes are in the population’s genetic pool, they can’t be removed and the net effect is that a sub-species takes the place of what we now think of as the human race (it’s a snapshot because animal designs are always in transition). If one design is too popular, despite huge numbers we will have reduced the genetic pool and will create a higher proportion of abnormalities previously associated with inbreeding (low intelligence, webbed toes etc.). Engineered microbes can improve animal health (or create super-plants) but might be fertile territory for an unknown virus or bacteria when it adapts in favour of spreading in those conditions. Another possible problem which could wipe out species faster would be if gene-transformation technology passed into the hands of the public, i.e. the ‘edit yourself at home kit’. Firstly, someone could edit a lethal virus (Marburg, Ebola, Smallpox) to be airborne and then hold the world to ransom. Secondly, the engineered humans could regard themselves as superior (intelligence, durability, faster reactions, requiring less sleep), petition for rights as a separate species and then replace the naturally evolved and inferior population that produced them.
15. Losing your mobile phone
This isn’t meant literally but it does illustrate the point. We could develop technology so advanced that we can sit back, take it easy, forget the need for acquiring knowledge and skills in our own heads, then when that technology we rely on for life support suddenly fails, no one knows how to fix it (see Asimov’s Foundation and Empire). A vast population descending to hunter-gatherer status isn’t practical because there isn’t enough to hunt and gather.
16. Toxins.
There are many chemical toxins in the environment, some natural (nitrogen is a toxin we breathe) and some man-made (alcohol, carbon monoxide, industrial pollution). Some are carcinogenic and others impair fertility. Some are released for decades before they are found to be a problem (asbestos) and others are inert until the react with another substance when dumped. There is a possibility that a compound could be released in significant quantities, react with another compound we’ve never considered it would be exposed to and disrupt reproduction on a global scale.
17. Weapons.
The nuclear bomb and neutron bomb are designed to remove human life and, yes, the winter and acid rain and radioactive contamination will account for a lot of people too but there will always be some survivors to continue the species. With bacterial and viral bioweapons (as opposed to chemical neurotoxins which don’t have mobility), that will not necessarily be the case because their activity doesn’t stop while the host population remains alive. It could be all of us but, alarmingly, biological weapons are even more likely to be used because of the modern development that they might be genetically pre-coded to only target one gene that appears predominantly in one race, i.e. the person who released it would not be deterred by a risk to themselves.
18. Particle accelerators.
When the Large Hadron Collider and the Relativistic Heavy Ion Collider (RHIC) are replaced by even more powerful designs, the collision and detection of new fundamental particles might create a subatomic pin-point black hole which, if not magnetically contained, would start a chain reaction which extends to all matter, over-writing the world. Alternatively, antimatter could be created and when that meets ordinary matter of any kind it would cease to exist — releasing an enormous burst of heat and radiation energy. History tells us that when humans are faced with an unknown of this kind, e.g. when they did not know whether the first atomic bomb chain reaction would expand indefinitely and remove the whole planet, they have gone ahead and pressed the button to find out.
19. Nanobots and nannites.
There is a huge incentive to press ahead with this technology. Imagine controlling a bot-swarm that repairs an artery or removes your cholesterol build-up from the inside. In deep space exploration, the number of humans required to undertake all the repair jobs is limited by the oxygen production or storage capacity of the vessel, but what if your maintenance force weighed almost nothing and required no oxygen at all? Atomic-scale machines that can make any product you want, no matter how complicated, bots that can replicate themselves by building identical copies from the metals that surround them and then copying across their software. However, in Eric Drexler’s book ‘Engines of Creation’, he notes that exponential growth of these tiny machines would have the capacity to reduce the world to grey goo very quickly. Sooner or later, someone’s armed forces would use the bots to carry out their assassinations, then a copy of a bot might reinterpret the instruction to damage someone into a license to damage everyone. Once in place, the same thing could happen by deliberate human action, as a ransom or revenge mechanism.
20. Nuclear fusion.
“In nuclear fusion, you get energy when two atoms join together to form one. In a fusion reactor, hydrogen atoms come together to form helium atoms, neutrons and vast amounts of energy. It’s the same type of reaction that powers hydrogen bombs and the sun.” (How Stuff Works). In the event of a chain reaction (loss of magnetic containment), a continuous ripple of connected matter could fuse and release an exceptional quantity of energy, essentially turning the Earth into a small star.
21. Robots!
Both ‘I Robot’, by Isaac Asimov and ‘Love in a Robot Dawn’, by C.W. Crowe look into the scenario of a mechanical race with the capability to dominate humanity, some questing their place in the Universe and others just getting on with it. People may also merge with robots and become augmented humans, as described in ‘The Waening’, by Blade Cort. The point is, when you tell an intelligent, problem-solving robot that protecting human life is paramount and the robot see that humans eat or enslave animals, yet humans are animals themselves, the dichotomy might cause the robot to conclude that humans are wrong and the same rules that humans apply to other animals should also be applied to them.
22. Aliens!
Contact with an alien civilisation has the potential to destroy us because an invasive animal species entering new territory normally tries to remove the apex predators that could threaten it first. On Earth, that’s the human race. The budgerigars and koalas will probably be left alone. “Advanced western civilization has had a destructive effect on all primitive civilizations it has come in contact with, even in those cases where every attempt was made to protect and guard the primitive civilization. I don’t see any reason why the same thing would not happen to us.” Gerard O’Neill (1979). Even when two civilisations meet and agree to live alongside each other, one usually becomes an underdog and dwindles. Given that the alien civilisation would have to be capable of interstellar travel, a technology we don’t have, that suggests that even in this best case scenario we would be the underdog. We can only hope that a race with this advanced level of development would also have grown an advanced morality to match, but as we haven’t achieved that yet it isn’t an assumption to bank on. There could also be pathogens, but we could get lucky there because the aliens would almost certainly not have our four (or the Earth system’s five) DNA nucleobases, adenine (A), cytosine ©, guanine (G), thymine (T); and uracil (U) and might not be able to affect us.
23. Popular delusions and crowd insanity.
500,000,000 people in the world have a psychological disorder (WHO figures). Some of them get themselves elected. ‘Extraordinary Popular Delusions and the Madness of Crowds’, by Charles Mackay, catalogues some of the great mass delusions of the past, from the crusades to witch hunts to tulip fever and then on to the investment scandals of the later centuries such as the Mississippi Scheme (France) and the South Sea Bubble (UK). In ‘Sourcery’, by Terry Pratchett, the Star People look at your left ear when you speak, not listening to anything you say, and continue their inexorable crowd-march to doomsday. Religious fervour has always had the power to pick up a million believers and hurl them against a stone wall, but nationalism and greed have the capacity to reproduce this behaviour too. It has happened in the past so it could happen in the future and probably will.
24. The stuff of God.
In the Old Testament, God kills over two million people, half a million of which were on his own side. The Bible also predicts an end of times and ‘The Rapture’, in which the devout are sorted out (if only they could be). Other holy creeds have their own prophecies of the last days. A lot of people believe that scripture of this kind is the literal truth (and a lot do not). Others believe it is merely told to convey a lesson. If the believers turn out to be right, our species and all species could be expunged on a whim. Indeed apocalyptic thinking originated in the world’s religions. As Arthur C. Clarke noted, “Any technology sufficiently advanced will become indistinguishable to magic”, so perhaps an extra-terrestrial force is not a god but would have godlike technology capable of inflicting the same result, so there would not be much difference to us if humanity was on the receiving end of it.
25. The dreamer awakes.
Some people say that evolution is only a theory, despite the fact that not a single scientific experiment since ‘On the Origin of Species’ was published in 1861 has ever had peer-authenticated findings that are not compatible with the theory of evolution. By this token, the Earth going around the Sun is also only a theory (the Heliocentric Theory) and the Earth being round (actually an oblate spheroid with 42km difference between the polar and equatorial circumference) is also only a theory, despite the evidence of our eyes. In truth, almost nothing at all is accepted by science as a fact, except in the field of mathematics. The reason that this happens is the Bertram Russell conjecture that “It is highly improbable but theoretically possible that the Universe was made only a minute ago and we were created with programmed memories”. This sounds unrealistic but because it is not possible to completely rule it out, some very obviously true things will forever be classified as theories. “Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?” What the philosopher was asking was, are we living in a false reality, someone’s dream? What happens if they wake up, i.e. which illusion collapses? As Edgar Allan Poe said “Is all that we see or seem but a dream within a dream?” Biologically, we don’t actually see anything directly, i.e. photons fall through your retina and trigger detectors which in turn trigger neural synapses, sending a signal to the brain which interprets the signal by building a picture for the brain and attaching that to other memories for context. Think about this: what would happen if the real neural signal for sight and sense was replaced with an identical synthetic one? You wouldn’t know the difference and really could be a blob in a jar.
