10 Reasonable Ways The World Might End
Everyone wonders how the world, as we know it, is going to ultimately end. After all, every other great biological dynasty has met its demise, and we shouldn't be so arrogant when contemplating our final destiny. My guess is that the actual Earth will be relatively unscathed, and probably bettered, by whatever event results in the eradication or massive depletion of the human species. It may take a while for the scars of humanity to heal, but the Earth isn't concerned with mere millennium, it's playing the long game. We're talking billions of years, eons.
Though we must wonder, how will we get to this destructive end? What will be our ultimate downfall? Will it be a pandemic? Infrastructure collapse via CME? Dwindling natural resources? Unpreparedness for a large asteroid? Supervolcano? Global sea level rise due to climate change? Artificial superintelligence? Oh yea, nukes? Let's explore some possibilities for the end times.
#1: Nuclear Annihilation
We could never blow up the Earth with nukes. The truth is, we wouldn't even leave a dent if we tried. That being said, the amount of nuclear warheads that we, as a species, currently possess is enough to fully eradicate ourselves, more than ten times. There wouldn't even be anyone to light the fuse for the second round. Plus, that's just the nukes that we acknowledge, over 17,000. Nobody really knows how many there really are, or what entities have been able to obtain these doomsday devices. As nukes continue to fall into the hands of increasingly volatile factions, so increases our chances of mutually assured destruction.
#2: Artificial Intelligence
What we should actually be concerned with is artificial superintelligence, which is the point when a computer or robot actually becomes smarter than the humans that created it. This implies the ability to learn from previous events and reason in a manner typically associated only with human intelligence. Another factor is the performance of an AI on a turing test, where it attempts to convince a human that it is also human. Though it will be a while before we achieve AI superintelligence, our future interaction with computers will be much more integrated than it currently is, and we already trust computers in almost every aspect of our lives. If these entities end up gaining access to the resources necessary to expand on their own intelligence, defend themselves, self-replicate, and power autonomously, we may become helpless in any effort to stop them from executing their sentient will. Let's hope they develop good intentions.
#3: Coronal Mass Ejection
Have you ever seen the Northern Lights or Aurora Borealis? Yeah, I agree, it's pretty sweet. What isn't sweet is the same phenomenon responsible for this astonishing light display could also wipe us from the face of the Earth. The lights are actually excited particles in our atmosphere that have been bombarded by electromagnetic radiation from the Sun. These radiation events, called Coronal Mass Ejections (CMEs), happen on a daily basis, and could potentially knock out the majority of electronics on our planet. Normally, our magnetosphere shields us from this phenomenon, but if the Sun lets loose a sufficiently large CME, and aims it ever so accurately toward us, the result would be a return to the dark ages. Just think about how quickly society would crumble if nothing went beep. Oh, and a CME isn't the only potential source of electronic assassination. A sufficiently disgruntled individual could detonoate a similar type of surge, an Electromagnetic Pulse (EMP), right from the comfort of anywhere on Earth. Good thing everyone's pretty chill right now.
#4: A deadly Virus or Bacteria
We have done everything in our power to ensure this to be a possibility. From overusing and subsequently weakening the effects of antibiotics, to the proliferation of worldwide travel, to the anti-vaccination movement. As a result of these factors, all it's going to take is one sufficiently resistant bug to destabilize society and bring humanity to its knees. We are already seeing a decline in the effectiveness of the influenza shot, and this is mostly because researching new strains is prohibitively unprofitable for the major pharmaceutical companies. If we keep on treating the health of our world population as an economic asset, it probably won't be long until something new and weird pops up and we're caught here padding our wallets whilst twiddling thumbs.
#5: A large Meteor/Asteroid
This one is pretty straightforward: big rock hit Earth, Earth go boom. We have paleontological evidence that proves this has happened numerous times in the past, causing catastrophic dying events. At the present, we have numerous theories as to how we could potentially nullify the probability of this happening to us. We have theorized anchoring rockets to the surface of an asteroid and nudging the trajectory away from Earth, we have proposed using gravitational forces to pull the rock away, we have even thought about blowing them up, though the latter proposal would likely produce more harm than good. The problem is, these are only theories. We currently have no proven method of preventing a disastrous meteor strike. If one hits before we have means to displace it, we will not get a second chance.
#6: Global Warming
We already know this is happening. Even though humans are incessantly concerned with whether or not this phenomenon is man made, which it is, the real problem is that it exists no matter what we ultimately decide to blame. We are terrifyingly close to reaching a CO2 saturation point that is beyond reconciliation. Once this happens, runaway climate change will persist no matter what we do. We will continue to see the ice caps melt, global sea level rise, and epic droughts that threaten the most basic components to our long term survival. We will not only be uncomfortably warm, we will be destined for an exhaustive societal collapse. The Earth will still remain, but it will not be a place that entertains human life.
#7: A Supervolcano
The most distressing fact about supervolacnoes is that we already know of one that is due for an exceptionally aggressive event. The Yellowstone Caldera spans nearly 1,500 square miles of Wyoming terrain and has experienced at least three supereruptions in the past. Each time this happens, a staggeringly vast amount of magma becomes displaced onto the Earth's surface. The eruption results in a significantly large amount of volcanic ash being thrust into our atmosphere to cause widespread disruption in our global ecosystem. The sky literally goes dark. Without sufficient radiation from sunlight to grow our food and power life, our chances of survival are overwhelmingly grim. The real bummer is that we don't think there's anything we can do to stop it.
#8: Ecosystem Collapse
If we keep making colossal alterations to our ecosystems, we cannot predictably rely on them to sustain us as a species. Like it or not, we are dependent on much of the other life that exists with us on this pale blue dot. If the oceans keep getting warmer, we will kill off the phytoplankton that currently produce about half of the breathable oxygen on our planet. As you may well know, we need oxygen to survive. If we keep overfishing our oceans, we will lose access to an invaluable food resource. If we keep demolishing niche organisms that exist in rain forests and other systems, we will lose our ability to reap the benefits of their varied biological traits. The fact is, we do not understand how current biodiversity contributes to our sustainability. If we keep hacking away at branches in our evolutionary family tree, there is no way of insuring our long term survival.
#9: Pissed off Aliens
Given the sheer enormity of our Universe, I personally believe it to be ludicrous to believe that we are completely alone. According to the most recent approximations of the Drake Equation, which uses pertinent coefficients to estimate the number of advanced civilizations, there are at least 1,000 examples in our galaxy alone. Given that even our Observable Universe consists of at least 225 billion galaxies, I'd say our certainty of at least one other intelligent species is rather conservative. The question is whether or not these entities can actually get to us. This would probably involve the development of a warp drive, or other FTL mode of travel. As unlikely as that sounds, it would be rather ignorant of us to assert that no one has figured it out yet. If a civilization is going to go through all the effort necessary to get here, they probably have an ulterior motive. I find it rather unlikely that they would just want to say hi and be on their way. Also, if they are smart/powerful enough to master FTL travel, our current line of defense would probably consist of a mundane annoyance to them. Even so, we will probably destroy ourselves before anyone else gets here to do whatever they're going to do. So we got that going for us.
#10: Zombie Outbreak!
Though this is an admittedly comical inclusion, there are actually parasites that control the minds and bodies of their host. This phenomenon is well documented in the zombification of ants, spiders, grasshoppers, crabs, rats, fish, snails, caterpillars, and many types of larvae. Though we normally consider ourselves above these subhuman organisms, there isn't really a reliable biological reason for us to be immune to this type of takeover. Though we wouldn't be dead, as in the classical zombie case, many of the other distinguishing traits would be present. The most important of which would be loss of control of our bodily processes and the transmission of the parasite to other human hosts. All that would need to happen is a genetic modification of an existing zombifying parasite that would allow it to infect and interface with human control mechanisms. Sounds like the stuff of horror movies, but the science is actually there.