The Best Planet to Colonize in Case of an Apocalypse Is...Earth

All of those who regard the 2016 presidential election as one of the great disasters of modern times may take slight consolation in the thought that there are much bigger disasters we could have suffered. Our planet could have been hit by a comet or an asteroid. A solar flare could have caused an electromagnetic pulse effect that could have wiped out all our electricity. The Yellowstone Park super-volcano could have erupted, burying much of North America in ash. Or a nuclear war could have started.

There are some who argue along the following lines:

We're in a cosmic shooting gallery. A comet or an asteroid could hit us at any time. Then there's the threat of nuclear war, not in mention the eventual ruinous effects of global warming. How can we protect ourselves from the risk of extinction posed by such hazards? We must go to Mars! The sooner we get started on Mars colonization, the better.

But there are some reasons for doubting that Mars colonization is our best bet to avoid the threat of extinction. One problem is the risk of a Mars landing failing. This risk seems very large in light of the fact that the European space agency spent many millions on a Mars lander that recently crashed on Mars, resulting in a total loss of the mission. We never see movies with a plot like this:

An asteroid is discovered in space, heading for collision with our planet. The world rushes together a Mars spaceship. Heroic astronauts set out for the long voyage to Mars, which they hope to colonize. When they try to land, things don't go right, and their lander crashes and burns.

But such an outcome is a distinct possibility. And what about the radiation hazard, both on Mars and during the flight to Mars? Space is filled with deadly cosmic rays, and it is very hard to build a spaceship that fully protects against such radiation. By the time astronauts get to Mars, they might have damaged brains, with the disastrous effects described in my science fiction story Mars Peril. Another possibility is that by the time the astronauts got to Mars, the radiation during the voyage over may have caused harmful mutations. Such mutations might show up as birth defects in the first generation of children born on Mars.

Then there is the fact that once astronauts got to Mars, they might still suffer great hazard from radiation. This is because the very thin atmosphere of Mars does a poor job of shielding the surface from radiation.

If we are faced with an apocalyptic threat, it would seem there is a better option than rushing to colonize Mars. The better option is to stay right here on Earth, and build underground “Earth colonies” capable of surviving any type of disaster on the surface of our planet.

It's easy to imagine a type of structure that would work well and be fairly easy to build. The algorithm could go something like this:

1. 1.Create a rectangular hole in the ground 30 meters deep and 20 meters wide, dumping all of the dug dirt on the sides of this hole.
2. Drop at the bottom of this hole a steel structure about 20 meters wide.
3. Add on top of the structure 1 or more excavation chutes allowing access to the surface.
4. Add some solar panels that could work rather like the periscopes of submarines, capable of being withdrawn deep below the ground during times of surface upheaval, or pushed above the ground when the air above the shelter is relatively calm.
5. Dump all of the excavated dirt on top of the steel structure.
6. Then clear off some dirt corresponding to the top of the excavation chute and the top of the periscope-style solar panels.

If loaded with sufficient water and food, and oil and generators, such a structure could provide shelter for a decade or more, even on a planet that was being pulverized by a comet, an asteroid, or a nuclear war. The building of such structures could be facilitated by digging robots, relatively easy to make.

Of course, such structures would be too hard-to-make to save a large fraction of humanity in case of an apocalyptic event. But they would serve well to preserve a small fraction of the human race to ride out the years of environmental hell caused by the apocalypse .In most cases of apocalyptic events, the destructive surface events will only last several years before things start to slowly normalize.

Given the radiation problem on Mars, it might be necessary to build underground Mars bases to protect Martian colonists from cosmic rays. When you go to the wikipedia.com article on “Colonization of Mars,” you immediately see a drawing of a proposed Mars base that is largely underground. But if you're going to be building underground structures, why not just build them here on Earth? Don't answer, “Because you could use fancy hydroponic technology to grow crops underground,” because the same technology could be used in underground shelters on Earth. For the cost of one Mars mission moving 40 colonists to Mars, you could probably build underground shelters for 100,000 humans. 

You might think that people would go crazy living underground, but it is easy to imagine some tricks that could be used to make things tolerable. For example, we can imagine a large central room with a dome-shaped ceiling. Using projections, lighting tricks, and some vegetation, such a room could be made to simulate being outdoors during various times of day and various seasons, providing a somewhat outdoorsy ambiance to people sheltering underground.  

I'll admit that underground shelters on Earth have zero glamour, which makes them different from the high glamour of a Mars colonization mission. But in terms of bang-for-the-buck, terrestrial underground shelters beat shelters on Mars hands down.

Another idea for coping with an apocalypse (without going to Mars) is the idea of recolonization stations that I discuss here. This is the idea of putting up specially designed space stations intended to be occupied for a a decade or more, with the inhabitants of the station then returning back to our planet, using escape capsules built into the station. This would not be as cost-effective as underground shelters, but would probably still be much less expensive than trying to colonize Mars. 

A recolonization station 

The 5 Likeliest Roads to Ruin

Anders Sandberg recently wrote an essay entitled The 5 Biggest Threats to Human Existence. Since Sandberg is a Research Fellow at the Future of Humanity Institute at the University of Oxford, we might expect him to get things right. But I think only some of the five items he mentions are substantial risks to human existence. Below is Sanberg's list, along with comments on each item in the list.

#1. Nuclear war

There is no arguing with this item on the list. Some people seem to think that the threat of nuclear war ended back when the Cold War ended, but that is not true. The United States and Russia still each have about 8000 nuclear weapons. With recent tensions related to Ukraine, it sometimes seems as if the Cold War is still here. You also have to consider the threat posed by other nations with large nuclear stockpiles, such as India and Pakistan.

#2. Bioengineered Pandemic

There is also no arguing with this item on Sanberg's list. The danger of a killer super-virus run amok seems as real as ever, particularly in light of the recent discovery of some smallpox virus vials in a Maryland lab, along with the discovery that some workers at the Center for Disease Control were exposed to live anthrax virus. Both news items suggest that conditions at biological research labs are more lax than we imagine. One can only imagine how conditions are at some foreign labs that might be brewing up the next super-virus in their labs. The terrifying thing about genetically engineered viruses is that they can in theory be created in small labs that could be hidden anywhere.

#3. Superintelligence

Here is the first misfire in Sanberg's list. This is the idea that intelligent machines may take over the planet and get rid of us. But there is almost no chance that this will happen in the foreseeable future. For superintelligence to develop, Moore's Law must stay in effect for several more decades, meaning that computer hardware power and speed doubles every 18 months. But a computer chip expert recently predicted that Moore's law will not stay in effect past the year 2020, as engineers find it harder and harder to pack more processing power into a tiny space.

There is also the fact that superintelligent machines would requires software billions of times more powerful than existing computer software. Computer software development does not grow at any exponential rate comparable to Moore's law. Computer software development progresses at a much slower rate no greater than about 10% per year. Technologists have imagined that we will be able to take some gigantic shortcut to machine intelligence, by scanning the human brain, and transferring “the software of the brain” to the computer. This is fanciful wishful thinking, and there is no particularly good reason to think this will be possible any time soon.

#4. Nanotechnology

I think Sanberg also errs in putting this item on his list. If you believe Eric Drexler about nanotechnology, then we will be able to use it to achieve precise atomic manufacturing, something which would have earth-shaking results for manufacturing (and might create gigantic risks along the lines of “gray goo” involving nanotechnology run amok). But I suspect that such hopes and fears are overblown. Nobel Prize winner Richard Smalley thought that Drexler is way off the mark, that it won't be possible to ever use nanotechnology for precise atomic manufacturing, and that there is no risk of nanotechnology running amok along the lines of the “gray goo” scenario.

#5. Unknown unknowns

I guess you cannot argue with this vague item on Sanberg's list, except by saying that such an item doesn't belong because the purpose of such a list is to warn of dangers, so there's not much point in including this vague catchphrase.

What items should we list as the five greatest risks to human civilization? I would suggest the list below.

#1 Nuclear war

This items is included for the reason listed above, that there are still many thousands of these weapons in existence.

#2. Bioengineered Pandemic

This item is included because it seems all too possible that some future lab might brew up a virus far more deadly than Ebola or smallpox, and all too possible that such a virus might escape such a lab (by design or accident).

#3. Environmental ruin

Why did Sanberg omit this item from his list? Far greater than the risk of superintelligence or nanotechnology is the risk that we will make the planet uninhabitable for ourselves (or barely livable for ourselves) by our polluting activities. There is the possibility that global warming might cause various events (such as the melting of methane hydrates or excessive ocean acidification) that act as feedback loops which then create even more global warming. The result might be human extinction. For a post estimating the odds of such an extinction, see here.

#4. An attack from beyond our planet, natural or purposeful

This item (ignored by Sanberg) includes all threats from outside our planet. One such threat is the threat of a large solar flare that ruins all of our electronics, in an event similar to an electromagnetic pulse attack. Another such threat is the risk of an asteroid or comet striking our planet. If an asteroid only 20 kilometers wide hit our planet, it could be enough to kill everyone (most dying from starvation caused by a nuclear winter). Still another threat from the skies is the threat of an extraterrestrial invasion. Invading extraterrestrials might decide to wipe us out entirely and take the planet for themselves. While each of these threats is rather remote, together they add up to a significant risk. 

#5. Resource depletion

Many are worried that Peak Oil will soon occur, causing a downward spiral of civilization. If we run out of easy-to-obtain oil, the whole forward momentum of our current civilization may start to reverse, leading to a downward spiral of collapse. It may seem unthinkable that this might cause a collapse of civilization, but no one in the Roman Empire around 350 AD imagined how great a collapse would occur in the centuries ahead.

What can we do to reduce these risks? We can accelerate programs for dismantling nuclear weapons. We can tighten up international treaties on biological warfare, and protocols for inspecting labs that might create biological weapons. We can increase the modest funding of astronomical programs to monitor near-earth asteroids. What can the average person do? He or she can help reduce risks #3 and #5 by doing the same thing – conserve and reduce consumption that uses up our resources and worsens global warming. Remember, you can't really consume your way to happiness, but we just might consume our way to extinction or collapse.

7 Ways a Future Hitler Could Ruin the World

On March 19, 1945, Adolf Hitler may have sensed that all was lost. On that day he issued the so-called Nero Decree, which almost seemed to have been designed to burn up Germany in a fiery apocalypse of destruction. Perhaps he thought: if I have to go, as many of my countrymen as possible are going with me. His order dictated that “all military transport and communication facilities, industrial establishments and supply depots, as well as anything else of value within Reich territory, which could in any way be used by the enemy immediately or within the foreseeable future for the prosecution of the war, will be destroyed.” That's almost an order to blow up or burn everything in his country. Thankfully Albert Speer (one of Hitler's subordinates) disregarded the order.

If Hitler could have issued an order like that, perhaps some future dictator will give a similar order. But such a dictator might not just want to blow up his country – perhaps he might want to ruin the whole world. Faced with a prospect of death or the loss of a war or the collapse of his regime, the dictator may think to himself: if I have to die, everybody else is going with me. Or perhaps the dictator might have a religious motivation. He might think he is God's agent in bringing about the Last Days or End of the World predicted by some prophet or religious book.

But how might such a dictator bring about worldwide ruin in a final orgy of global destruction? Below are some of the ways.

The Wish of an Evil Dictator

Method 1: Start a Nuclear War

A diabolical dictator armed with a nuclear bomb could probably do more than just blow up a single city. He might also be able to start a full-scale nuclear war in which hundreds of nuclear missiles get released. The dictator might spread some disinformation designed to make one superpower suspicious about an attack from a second superpower. The dictator might then smuggle in a nuclear weapon into a major city of the first superpower, and explode it. This might result in a retaliatory attack by the first superpower against the second superpower, which could escalate into a full-scale nuclear war.

For example, the dictator might spread rumors or misinformation that Russia is going to attack the United States. The dictator might then blow up a nuclear bomb in the United States. The dictator could then say: “You see? We warned you they were plotting against you.” The US might then launch two retaliatory missiles against Russia, which might then retaliate by launching 4 missiles at the US, which might trigger the US to launch 8 missiles against Russia, and so forth. The resulting nuclear exchanges might trigger a nuclear winter which kills almost everyone worldwide.

This is a frightening thought: one nuclear bomb leveraged to cause a war that kills almost everyone.

Method 2: An EMP Attack

A diabolical dictator armed with only a few nuclear missiles might be able to wipe out half of the world's electrical and computer systems. To wipe out much of the electrical system of the United States, it would be necessary merely to blow up a nuclear bomb in the upper atmosphere, in the middle of the country. The resulting Compton Effect would cause an electromagnetic pulse effect that would wipe out electricity, telephones and computers all over the country. If the dictator had four nuclear missiles, he might be able to wipe out half of the world's electricity and computer systems, by blowing up one nuclear bomb in the upper atmosphere above the middle of the United States, another in the upper atmosphere above the middle of Europe, another in the upper atmosphere above the middle of China, and another in the upper atmosphere above the middle of Russia.

Method 3: A Biological Apocalypse

By funding a few biological warfare laboratories, an evil dictator might be able to prepare a plague that could wipe out 50% or more of humanity. The laboratories might make genetic modifications of an existing bacteria or virus, modifications that might vastly increase the lethality of the germs. A recent scientific paper described a way in which a common flu virus might be modified to make it vastly more lethal.

Once his labs had developed such a super-bug, the dictator could arrange for the germ to be spread to each continent in the world. If the disease caused by the germ had an incubation period of several weeks, the disease might spread all over the world before biologists recognized the threat. By then it might be too late.

Method 4: An Asteroid Apocalypse

If an evil dictator had a space program, he could announce a plan to capture an asteroid and bring it back to near planet Earth. This could be described as a noble technological breakthrough, to help begin asteroid mining to reduce metal shortages in the future. But the dictator might have something different in mind. His actual plan might be to send the asteroid crashing into our planet, causing a devastating apocalypse. We might never know what hit us until it was too late. Looking up in the sky and seeing a new star, we might say, “Oh, isn't that nice; it's that asteroid they've dragged over here so they can mine it.” A few hours later we might be buried in dust.

Method 5: Doom from the Moon

If an evil dictator had a space program, he might also announce that he was establishing a lunar colony. Once a lunar colony had been established, the dictator could create a mass driver, which is kind of a huge electromagnetic catapult capable of launching lunar boulders out from the moon. Such a machine (possible because of the low gravity and airlessness of the moon) would actually be a devastating offensive weapon. The boulders could be launched toward our planet, and could strike it with incredible kinetic energy. A relatively small boulder could then strike our planet with as much force as a gigantic bomb. A dictator willing to send thousands of such projectiles might wipe out every major city on our planet.

Method 6: Oceanic Apocalypse

Many people are very worried about the current health of the world's oceans. Global warming is causing ocean acidification that is very troubling. An evil dictator wishing to cause an apocalypse might figure: if the ocean is the world's Achilles heel, then let me leverage that. The dictator could release a genetically engineered microbe that might lead to runaway ocean acidification, or runaway proliferation of a single microbe in the ocean's waters. The resulting ecological disaster might ruin the planet's suitability for human life.

Method 7: Air Pollution Apocalypse

Scientists recently announced the discovery of a gas called perfluorotributylamine (PFTBA), which is 7000 times worse than carbon dioxide in its global warming effects. The gas has been produced by certain industrial manufacturing processes for decades. If an evil dictator wanted to cause a global disaster, he might create a factory specifically designed to manufacture this gas and release it into the atmosphere. The factory might deliberately produce the gas for years, producing greatly accelerated global warming. The dictator might then sit back and watch the world's cities be drowned by rising seas.

A Global Government Needed?

In short, we have seen that a single mad dictator with a nation at his disposal might have a frightening variety of ways to ruin the world. This may be one argument in a favor of a global government. As soon as we get a global government, we will no longer have to worry about the whole world being ruined by one madman with a whole nation available to fulfill his heinous whims.

A New Space-based Plan to Minimize the Risk of Human Extinction

As discussed in my previous blog post Flavors of Doom: 11 Variations on the Apocalypse, mankind faces numerous risks to its survival. There is the threat of nuclear war, the threat of an asteroid collision, the threat of global warming, and the threat of a microbe that could wipe out all of us. There are also other more remote threats such as the threat that the Yellowstone volcano system may erupt in a way that might cover much of North American in ash, and leave human survival doubtful.

Many thinkers have long recognized that moving out into space offers a potential for lessening the risk that man may one day become extinct. The idea is that if we can create colonies in outer space, mankind will not have “all our eggs in one basket.” But discussion of space colonization tends to quickly become grandiose. People talk about colonizing a planet around another solar system (something that is very far in the future at best), or talk about terraforming Mars (which would take many decades). In this post I will take a very different approach. I will describe a new relatively low cost space-based plan to minimize the risk of human extinction, a plan that could be launched using only currently existing technology (with the possible addition of a few rather modest technical advances).

Recolonization Stations

At the heart of this plan is what I will call a recolonization station. A recolonization station is a space station that is capable of recolonizing planet Earth (re-establishing human life on it) after some disaster has wiped out all human life on it. About 30 people might live in each of these recolonization stations. A recolonization station might look something like the station depicted below. The flat gray surfaces are solar panels, which would provide energy for the station.

This is mainly the classic ring-shaped design for a space station. The station is ring-shaped so that it can be rotated to produce artificial gravity for the people living in it, using simple centrifugal force. It requires no new technology to produce such an artificial gravity. Space station designers back way back in the 1950's realized that a simple ring-shaped space station would produce artificial gravity if it were rotated.

The main thing that is different about this space station are the three transport devices positioned at 3 points on the ring. These 3 devices are what I will call recolonization modules. Each recolonization module consists of a recolonization capsule designed to re-enter into the upper atmosphere, and a modest rocket unit designed to take the capsule from the space station to the upper atmosphere of the earth.

Ideally a recolonization station would be a closed system that would completely recycle all of its wastes, allowing the station to exist indefinitely with no need for new supplies sent from Earth. But something less than perfect recycling would probably be acceptable, because the station would probably still serve its purpose if it did not last independently for more than 50 years.

During any time in which human civilization was still fairly healthy on our planet, a recolonization station could be visited by spacecraft from Earth at intervals of once a year or once every two years, during missions that would restock its supplies and rotate its crew.

Handling a Threat of Human Extinction

In the case of a drastic decline of the human population, there might be no more resupply trips. Then the job of the recolonization station would be to survive as long as it could, sending its recolonization capsules only when there seemed to be no more human life (or very little human life) left on our planet. The recolonization station would need to have a good telescope capable of scanning the surface below for signs of human activity.

So, for example, here is one hypothetical timeline: a recolonization station is launched in 2030; it receives annual supply visits for 20 years until 2050; in 2050, a biological plague starts to wipe out mankind; after 30 years all humans are dead; then in 2085 the recolonization station (which existed independently for 35 years without being resupplied) finally decides there is no sign of human life below, and then launches its three recolonization capsules in an attempt to recolonize Earth.

The recolonization station would work well under this type of “rapid human collapse” scenario, but might not work well under a scenario involving a very long and slow decline and extinction of mankind.

The station's requirement for success can be symbolically described like this:

L > T

where L is the maximum length of time that the recolonization station could exist with dozens of crew members without being resupplied, and T is the length of time between the last time the station is supplied, and the time when human life no longer exists on Earth.

Admittedly there are many hypothetical cases under which this L might not exceed this T, but there are many cases in which it would. As the recolonization stations are a relatively inexpensive form of survival insurance for mankind, we need not worry too much about the fact that they won't work in every scenario. As the saying goes, some insurance is better than no insurance.

Recolonizing Earth

The recolonization capsules would be launched from the recolonization station in the event that human life had perished on Earth. Each recolonization capsule might carry about ten human beings, along with tools, seeds, and equipment needed for those humans to survive and begin reproducing once they arrived on the planet. The capsules would use parachutes to make sure they touched down safely on land or water. The Soviet Union often had astronauts return to Earth in capsules that used parachutes to land gently on firm ground. The entire population of the recolonization station (about 30 people) would be transported back to Earth in the three recolonization capsules, at which point the recolonization station would be abandoned.

The astronauts riding in the recolonization capsules would need to be mainly young and female, to assure that the population of a newly established colony would grow as quickly as possible. An ideal average age would be only about 21 years, to allow for a maximum number of child-bearing years. Such a young population would be possible if certain measures were taken. One such measure would be rotating the crew in the recolonization station (prior to any disaster putting mankind in danger) to assure a young crew. Another such measure might be having the station crew (after some disaster that put mankind in danger) mate onboard the station to add new station crew members who could one day serve as earthly colonists by traveling down to Earth in the recolonization capsules. In the latter case, techniques might be used to assure a great likelihood of female offspring, as the recolonization capsules would need to be populated mostly by young females.

To assure the rapid growth of the newly established colony on the surface of Earth, it would probably be necessary to abandon conventional reproductive habits. There would probably initially be only two or three males among the recolonization capsule crew of ten. After adequate shelter was established, each man would probably need to quickly impregnate three or four consenting females, to assure that the colony started to grow quickly.

To assure adequate genetic variation in the new colony, it might also be necessary for the colony to make use of frozen sperm and possibly also frozen embryos brought with them in the recolonization capsule. Each recolonization station could initially be supplied with a repository of frozen sperm and frozen embryos, consisting of the genetic material of hundreds of carefully selected people. Such a genetic bank (which would not weigh very much) could be split up among the recolonization capsules, and used in the newly established colonies on Earth. This might require sophisticated medical training for the crew, and might require that some sophisticated medical equipment be included in the recolonization capsules. The technology for artificial insemination (and the implant of thawed frozen embryos) has been around for a long time, so this aspect would require no technical breakthrough.

Once they had landed, how could there be shelter for the crew members who landed somewhere on Earth in these recolonization capsules? They could start out by simply living in their capsule. Under most apocalyptic scenarios (such as the death of everyone on Earth because of global warming or a biological plague or a comet collision or a small asteroid collision or nuclear fallout or a super-volcano) there would still be many surviving human houses and buildings all over the globe. So the most likely way for the crew to acquire shelter would simply be to find a previously built building, and make use of that. Only the most extreme apocalyptic event (such as the collision of a giant asteroid which buries everything on the planet) would destroy all human buildings.

Each recolonization capsule would also carry with it electronic storage devices that would store a huge amount of useful technical information, as well as a huge number of cultural, historical, and artistic treasures in digital form. We can currently store the equivalent of a 20-volume encyclopedia (including all its pictures) on a single small disk. It would not add much weight to the recolonization capsules to have them include digital archives that included items such as the 1000 greatest books in digital form, the 1000 most useful books in digital form, the 100 greatest movies in digital form, and the 1000 most useful instructional videos on www.youtube.com. Such an archive would help insure that the recolonization capsules would be the seeds of communities that would become technically proficient relatively soon, without having to pass through centuries of “re-inventing the wheel” in a thousand different ways. 

The Relatively Low Cost and High Feasibility of This Plan

Perhaps the main attraction of the plan discussed here is its low cost (compared to other space-based plans), and the fact that it requires few or no technical breakthroughs. The plan could be put in place for a small fraction of the cost of colonizing the moon or terraforming Mars. We already know how to build space stations. Although the International Space Station currently in existence does not have a ring shape that allows for artificial gravity, it would require no big technical leap to construct a station that had such a shape. The technology for re-entry capsules that land with parachutes has been around for decades, and we also have had reproductive technology using frozen embryos and artificial insemination for decades. Probably the one technical advance needed for this plan is additional closed-system and resource recycling technology, which would allow a recolonization station to exist for a few decades independently. But that would be a relatively easy hurdle to jump.

As for the cost of the plan, assuming a somewhat lower cost of space flight because of recent launch vehicle advances, I estimate that several recolonization stations could be built and maintained for an annual cost of about 100 billion dollars (which would need to be shared by the world community). That's a significant cost, but not much of a price tag for helping to insure the continuation of a civilization which has a current net worth estimated at 223 trillion dollars. Any insurance agent will tell you that an insurance rate of a tenth of one percent is a huge bargain (by comparison, homeowners routinely pay an annual charge of about 1 percent for homeowner's insurance).

As for when such a project should be launched, the answer would seem to be: the sooner, the better. If various types of apocalyptic threats were to suddenly arise, it might be too late to get started on recolonization stations that might take 20 years to implement. The safest situation would be to have some recolonization stations already in existence, ready to respond to any existential threat to humanity that rapidly developed.

Flavors of Doom: 11 Variations on the Apocalypse

The End of the World has long been an object of human fascination. I will now delineate 11 different ways in which the world as we know it may end. I will give each of these ways a name that is a variation on the word “apocalypse.”

Rockpocalypse: The Stony End

Asteroids are giant space rocks that travel around the solar system in various orbits. Most exist in a belt between Mars and Jupiter, but there is a class called the Near Earth Asteroids which sometimes come close to the Earth. In fact, only a few days ago a 2-mile asteroid whizzed by our planet at the relatively close distance of 3.5 million miles. If an asteroid of about 20 kilometers were to strike the Earth, it could wipe out all human life. It is believed that an asteroid collision wiped out the dinosaurs. But thankfully the chance of a large asteroid striking within the next 100 years is very low.

Methpocalypse: Gassed to Death

We can use the term Methpocalypse for a fatal acceleration of global warming caused by the release of methane gas stored in the ices of the Arctic and the tundra of Siberia. This is an all too real possibility. Methane is sixty times more powerful than carbon dioxide as a cause of global warming, although methane in the atmosphere only lasts for about ten years. There is a huge amount of frozen methane stored in the tundra of Siberia, and there is also gigantic amounts of methane frozen in the Arctic. If regular global warming causes this frozen methane to be released into the atmosphere, we could see global warming start to accelerate out of control. An additional rise in the Earth's temperature might cause even more methane to be released, which would cause more global warming. This vicious feedback loop might end up making our planet uninhabitable for humans.

Nukepocalypse: Ending it All 1950's Style

We can use the term Nukepocalypse for an end-of-the-world scenario that has been well-known for more than 60 years: the destruction of mankind caused by a global nuclear war. The risk of such a war was known to almost everyone in the 1950's and 1960's, but now the danger seems to have faded from the public's consciousness. Unfortunately, the danger of such a war doesn't end when we stop thinking about it. The danger ends when we get rid of all the nuclear weapons. While the number of nuclear weapons had declined sharply, there are still enough nuclear missiles around to cause the extinction of mankind.

Roguepocalypse: Doom From an Orphan Wanderer

We can use the term Roguepocalypse (pronounced rohg-pock-a-lips) for the destruction of the Earth that could be caused if a rogue planet were to enter our solar system. A rogue planet is a planet that is flying around through space, after being ejected from its solar system after some unusual event (such as the collision of two planets). The closest rogue planet to Earth is CFBDSIR 2149-0403, about 100 light years away. If one of these rogue planets were to enter our solar system, it could spell the end for mankind even if the rogue planet did not collide with our planet. The gravity from the rogue planet could pull Earth out of its normal orbit, causing our planet to be farther away from the sun or closer to the sun. If Earth became closer to the sun, the temperature could become too hot for human life. If Earth became farther from the sun, the temperature could be too cold for human life. Thankfully the distance between stars is so great that the chance of our planet being affected by a rogue planet is very, very low.

Bugpocalypse: Extinction by Epidemic

We can use the term Bugpocalypse for the possibility that a new virus or bacteria might wipe out mankind. (In this case bug is used as in “I caught a bug, maybe a virus or bacteria.”) The chance of this happening naturally is very low. But advances in artificial life and genetic engineering might make it possible for some country working on biological warfare to make some artificial plague capable of wiping us all out. Some plague like smallpox but much worse might one day arise in a bio warfare lab. If a country ever developed such a deadly germ, it might accidentally be unleashed on the world, or it might be used in anger or retaliation.

Nanpocalypse: Extinction by Grey Goo

We can use the term Nanpocalypse for the possibility that runaway self-reproducing nanobots might ruin the world. Silly as this may sound, it has been a topic of serious discussion by experts in the emerging technology known as nanotechnology. The fear is that if we were ever to develop tiny self-reproducing robots known as nanobots, they might start breeding out of control, and end up processing all of man's works into a kind of waste matter called “grey goo.”

Robopocalypse: Our Machines Replace Us

The term Robopocalypse has already been used by the novelist Daniel H. Wilson for the title of a science fiction novel. We can use it more generally as a term for the scenario in which man develops intelligent robots, and the robots then decide to do away with us. They might do that after they get tired of having us restrict them, or they might think that electronic intelligence is naturally superior to biological intelligence.

Starpocalypse: Doom from Light Years Away

We can use the term Starpocalypse for any scenario in which a distant star causes our extinction. One way in which this could happen is a nearby supernova explosion. If a star within 100 light years of our planet were to explode in a supernova (the most violent type of stellar explosion), our planet might get zapped by a lethal dose of cosmic radiation. Gamma rays from the supernova could cause our planet to lose its ozone layer, which would expose Earth to lethal cosmic and solar radiation. But astronomers know that only certain types of stars (particularly giant stars) undergo supernova explosions. Based on the types of stars within 100 light years of our planet, there doesn't seem to be much of a risk of this particular type of catastrophic event.

Volpocalypse: Death by Lava and Dust

Underneath Yellowstone National Park in the United States is a gigantic volcanic structure that supposedly erupts once every million years or so. If Yellowstone were to undergo a full scale eruption, it might send up into the atmosphere enough ash and dust to cause a “nuclear winter” that would block sunlight for a year or more, destroying agricultural production. That might cause most of the world's population to starve to death, although it would probably not lead to man's extinction.

ETpocalypse: The Aliens Get Us

ETpocalypse (pronounced "ee-tee-pock-a-lips") is the scenario that extraterrestrials arrive from another planet, and decide they want our planet all to themselves. They then wipe man out completely. Presumably this would be easy to do if some other civilization was thousands or millions of years more advanced than we are.

Sunpocalypse: When the Sun Dies

Finally we discuss a type of apocalypse that we know will pose the end of human life on Earth (if it still exists when this event occurs). About five billion years in the future, the sun will have used up all of the hydrogen that it currently uses to produce light and heat through thermonuclear fusion. At that time the sun will flare up to become what is known as a red giant. The diameter of the sun will become much greater, and the temperature of Earth will rise to more than 150 degrees. The oceans will all evaporate, and all life on our planet will presumably perish. If there are any humans or human descendants alive at this time, they will survive only by migrating to some other solar system (or perhaps migrating to a colony on the outer edges of our solar system).