Consumed by the Apocalypse
Of all the species to have ever lived, all but a tiny fraction have gone extinct. At some point in the future, the same fate will befall humanity. It may take centuries. It might take eons.
But extinction is unavoidable. The future is fraught with uncertainty, and the apocalypse never seems too far away. Nearly 800,000 years ago, an approximately 1-kilometer-wide asteroid collided with Earth. The crater has yet to be located. But fragments from the impact have been found scattered across the Eastern Hemisphere. An expansive strewn field that covers up to 30% of the planet's surface.
Our distant ancestors were not only alive to witness this event but managed to adapt and survive. Impacts of this magnitude occur roughly once every half a million to two million years. More devastating impacts, like the one that nearly wiped out the dinosaurs, are far less frequent. Possibly striking once every one hundred million years. Whether a collision of this magnitude is survivable is a matter of debate. The kinetic energy released upon impact would be equivalent to the simultaneous detonation of billions of atomic bombs.
Those who survived the initial blast would be subjected to unrelenting earthquakes, firestorms, and tsunamis. A thick layer of smoke and dust would quickly envelop the globe and blot out the Sun. An impact winter that could last for months or even years. Darkness, freezing cold, and global famine would throw the world into chaos.
In spite of this, long-term survival is not inconceivable. Small pockets of humanity may take refuge underground and would at least be given a chance to rebuild civilization. But, make no mistake...
...it would be a close call. The survivability of an impact also depends on how much time we have to prepare. More than 90% of nearby asteroids and comets larger than 1 kilometer have already been detected. If one of them were on a collision course with Earth, we'd know for decades or even centuries in advance.
But this was not always the case. In 1983, a 9-kilometer-wide comet was only spotted two weeks prior to its closest approach. That's two weeks of preparation had it been aiming for Earth. While things have significantly improved since 1983, space is impossibly vast. In 2019, an asteroid capable of leveling a city was detected the day before it flew five times closer to the Earth than the Moon. While the odds of an extinction-level collision are remote, it's not impossible.
There is a class of objects known as Damocloids. Damocloids are typified by their highly eccentric orbits and low reflectivity. Meaning, they periodically pay us a visit and are extremely difficult to detect. We're currently tracking about 200, but there could be hundreds more tumbling through the Solar System.
Damocloids are, on average... ...16 kilometers wide. If one of them were on a collision course with Earth... ...there might not be any warning. When massive stars die, they explode. If a star went supernova within 30 lightyears of Earth, it would be cause for concern.
Fortunately, more than 90% of the stars within this bubble have already been discovered. None of which are at risk of exploding anytime soon. But some supernovae can still pose a threat from thousands of lightyears away. It's a gamma-ray burst. Produced by only the most violent explosions in the universe. Instead of a spherical blast, a gamma-ray burst will channel the explosion into two highly concentrated beams.
More energy is released in a few seconds than the Sun will radiate in its entire lifetime. The biological effects of a nearby supernova or gamma-ray burst are poorly understood. We do know that the atmosphere would absorb much of the high-energy radiation.
But this may also strip the Earth of its protective layer of ozone. If so, harmful levels of ultraviolet radiation from the Sun would penetrate down to the surface. Certain chemical reactions may also darken the sky and induce global cooling. A cosmic winter of sorts. This could last for years and would be lethal to many plants and animals.
In fact, a gamma-ray burst might be responsible for a mass extinction that killed roughly 70% of all marine species nearly half a billion years ago. Now, humanity could easily protect itself against ultraviolet sunrays, but living through a mass extinction would not be a pleasant experience. While some authors have painted a far bleaker image, with one hemisphere effectively sterilized by intense radiation. These findings have been contested in recent years. The latest research identify ozone depletion as the primary threat.
Nevertheless, a gamma-ray burst sniping the Earth from across the galaxy is extremely improbable. All of them have so far been extragalactic in origin. Much too distant to pose a threat.
While there are a few potential candidates within the Milky Way, none of them appear to be directed at the Earth. Apart from impact events and stellar explosions, the foreseeable future is free of cosmic threats. Other eventualities are either too improbable or won't happen for millions of years. Ample time for us to prepare... ...other calamities permitting. Around 74,000 years ago, a large volcano erupted in Southeast Asia. It is the most powerful volcanic eruption in human history.
For up to two weeks, it spewed enormous quantities of ash and dust into the atmosphere. Enough to block out the Sun and potentially cool the planet. A volcanic winter. But there's great uncertainty about the effects of the eruption on both the climate and humanity. It ranges from severe to mild. With the latest research supporting the latter.
In either case, this is good news. It means that supervolcanic eruptions pose little to no threat to human existence. After all, if early humans stood a chance, then so should we. But there is something even more destructive than supervolcanic eruptions. It's known as a flood basalt event.
The largest one occurred 250 million years ago. An enormous outpouring of molten rock covered a region of Siberia the size of Europe. And it just so happens to coincide with the deadliest mass extinction in history.
The good news is, flood basalt events are both rare and slow. Instead of a singular event, it's a series of eruptions taking place over thousands or even millions of years. As such, even if one began tomorrow, it might just be slow enough for us to adapt and survive.
Throughout the centuries, pandemics have exacted a heavy toll on humankind. Among the worst was the Black Death. In less than a decade, it killed between 25 and 60% of the European population.
The total death count is unknown. At least tens of millions. The Columbian exchange of diseases and the Spanish Flu claimed the lives of many millions more. The tragedy of these pandemics and epidemics notwithstanding, they never came close to extinction. None of them killed more than a few percent of the global population.
For instance, the Spanish Flu infected nearly one-third of humanity yet the vast majority of cases did not result in death. A pathogen that not only infects but also kills every single member of a species is difficult to imagine. In fact, there are very few examples of infectious disease driving a species to extinction.
With that being said, it's not inconceivable. For instance, pathogens that can pass between multiple species can be far deadlier than those limited to just one. The H5N1 avian influenza, also known as the bird flu, is one such virus. So far, it's transmissible between humans and birds, but it can't sustainably spread among humans.
However, laboratory experiments have shown that it may eventually acquire this ability through natural mutations. If so, it could easily become the worst pandemic in human history. But even this horrifying proposition does not come close to extinction. In a worst case scenario, most of humanity would still survive.
Pandemics are complicated. It's a topic that's more relevant now than ever before and can not possibly be done justice in a few short minutes. But in the narrow context of human extinction, it seems unlikely for nature to stumble upon that perfect storm.
Apart from volcanic eruptions and natural pandemics, the Earth has no inherent means of eradicating the human race. No other form of natural calamity is powerful enough to threaten our existence. As such, the most immediate threat to humanity has, for a long time, been, and continues to be... ...humanity. While nature may struggle to devise a world-ending pandemic, it may not have to.
Biotechnology has now advanced to a point where we can engineer pathogens in a laboratory. While this can greatly benefit our understanding and treatment of infectious diseases, it's not without risk. Accidental breaches of containment have happened on multiple occasions. And these experiments are not always conducted in the name of science. These engineered microbes are concerning because their destructive potential far exceeds that of their natural counterparts.
They can be deadlier, more transmissible, and less treatable. And the rapid pace of technological progress is constantly lowering the threshold for bioengineering. His biggest concern was- He said it in so many words, That a small group of dedicated scientists could create an altered biological agent that could wipe out humanity as we know it. Technically speaking, you can do almost anything with a microbe. The real question is, will you end up with a microbe that functionally will do the things that the concerned person at your hearing said. Namely- Essentially wipe out everyone from the face of the Earth.
Again, that's... ...conceivable, although it's inconceivable. But it is, in fact- Anything is possible. It would be very very difficult to do that. Extraordinarily difficult.
Even in the best of hands to, not only do the engineering... ...to get a microbe that has the characteristics but be able to spread in a way... ...in which it has virulence, transmissiblity, and the ability to go in a sustained transmissible way. Not impossible but very very difficult to do. A nuclear holocaust is among the most infamous doomsday scenarios.
Since the end of World War II, we have, on numerous occasions, been driven to the brink of nuclear conflict. Sometimes by accident. Sometimes by very intentional brinkmanship. The nuclear stockpile currently stands at more than 13,000 warheads.
The vast majority of which are owned by Russia and the United States. In the event of an all-out nuclear war, these thousands of bombs could instantly vaporize hundreds of millions. But the explosions are only the beginning. The real danger of a nuclear conflict is the aftermath.
Much like an impact event or supervolcanic eruption, a thick layer of smoke and dust would quickly envelop the globe. A nuclear winter that not only blots out the Sun but showers the world in radioactive fallout. Firestorms, radiation poisoning, and mass starvation could easily claim the lives of billions. However, because humanity is not evenly distributed across the planet, some regions would be less affected than others. Island nations like New Zealand, for instance, are all but certain to survive.
While the effects of a nuclear holocaust are almost too dismal to contemplate, it is not typically regarded as an existential threat. Artificial intelligence has had a profound impact on modern society. From self-driving cars and virtual assistants to social-media algorithms and facial recognition. But some experts are concerned about the future. A future in which intelligent machines become more intelligent than humans. The concern is not so much about evil robots as it is about misalignment.
A misaligned intelligence is one that's not properly aligned with human goals and values. A system that becomes dangerous, not due to any malicious intent, but due to an oversight in its programming. An unforeseen loophole that allows it to do things it was never intended to do. If such an entity was sufficiently intelligent, it could become unstoppable.
Another concern is known as the intelligence explosion. It's a machine that can upgrade itself and thereby increase its own intelligence at an exponential rate. Moments after creating such a system, it could far surpass the combined intelligence of all humans that have ever lived.
Such an entity may have little to no regard for human affairs. Not unlike humanity's disregard for species less intelligent than us. With that being said, these concerns are far from universal. In 2016, a survey of more than 300 machine learning experts was conducted. On average, they gave a 50% chance of an artificial intelligence surpassing all human abilities by 2061.
But as you can see from these faded lines in the background, there's tremendous variation between individual respondents. Some think it will happen in a few years. Others believe we're more than a century away. When asked about the impact of this technology, the majority of respondents believed in a positive outcome. Extinction was only given a median probability of 5%.
Artificial intelligence is not the only emerging technology with the potential for human extinction. But the problem with assessing their risk is that we have no precedence. We can estimate the likelihood of an asteroid impact by surveying the geologic record and our cosmic neighborhood. But there's no historical context for artificial intelligence or self-replicating nanomachines. When the first nuclear device was detonated in 1945, there was a genuine concern that it would ignite the atmosphere and incinerate all life on the planet.
In fact, one of the observers was so taken aback by the enormity of the explosion that, for a brief moment, that's precisely what he thought had happened. While this doomsday scenario did not come to pass, it's a cautionary tale. No one really knows what the future will bring. All we can do is proceed with caution and hope for the best.
Over the past few decades, species across the plant- and animal kingdoms have been disappearing at an alarming pace. Some 10 billion trees are cleared every single year. While animal populations are rapidly declining.
Many species are also going extinct. The global rate of extinction is now tens or even hundred of times greater than before humans conquered the planet. And it's accelerating. Upwards of one million species are now threatened with extinction. At the core of this immense loss of biodiversity is overconsumption driven by overpopulation. Humanity is now depleting three quarters as many resources as the Earth can naturally replenish.
Meaning, we will soon need a second Earth just to break even. From deforestation and defaunation to pollution and climate change, no shocking graph nor depressing slideshow can fully convey the totality of our destruction. Our relationship with nature is so utterly broken that many fear we are now heading for extinction. That this unraveling of nature will be mankind's undoing. While some of the most comprehensive assessments to date do indeed paint a truly dystopian image of the future.
None of them forecast total annihilation of the human race. We may turn the planet into a living hell, but a livable hell it would seem. However, some scientists argue that these assessments are severely underestimating the gravity of this crisis. That the sheer magnitude of our destruction "is difficult to grasp for even well-informed experts." Some have also voiced their concerns about potential tipping points.
A threshold that, once exceeded, may trigger an irreversible decline of ecosystems around the world. A global ecological collapse from which recovery becomes virtually impossible. But it's not all doom and gloom.
While the rate of deforestation is alarmingly high... ...it has been slowing down over the past three decades. While the transition has been infuriatingly slow... ...more and more countries are phasing out fossil fuels in favor of renewable energy sources. So, in no way should human extinction, which is the most extreme outcome, be regarded as inevitable. Climate change mitigation and nature conservation efforts are all but certain to prevent that from happening.
But, at the same time... ...that's how low we've set the bar. What surprised me while making this video is just how difficult it is to truly wipe out everyone. Many catastrophes can drive us to the brink of extinction, but all of them struggle to cross the finish line. So that should be somewhat reassuring. Even if humanity was reduced to a few hundred individuals, a full recovery might still be possible. It would undoubtedly take many thousands of years but recovery would not out of the question.
And the more we expand beyond the confines of Earth, extinction from any singular catastrophe becomes increasingly unlikely. Perhaps the apocalypse won't be dealt by a swift decisive blow but instead a gradual faltering decline. One disaster bleeding into the next until the final embers of humankind silently fade away. Regardless, it won't happen anytime soon.
After all, we made it this far. Millions of years of evolution, countless disasters, and humanity is still standing. That is perhaps the best reassurance that the world is still gonna be there tomorrow. Thanks for watching :)
2021-01-19 22:08
