Extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. This may be accomplished through any natural or directed means, so long as it gets results.
Extinctions happen every day, so it's not like you should really be worrying about the Concept of extinction, per se. It is the rate of extinctions that may concern you, if you were so inclined.
Because everything in the ecosystem exists in a fragile balance, the extinction of one butterfly species may be felt as ripples through the food chain in deeply upsetting ways. If a single beetle species dies out, then most likely nobody will fucking notice. If enough birds and fish and sea turtles and newts and tree frogs and baby pandas and obscure rhinoceroses disappear, then expect to start eating cockroaches as your sole staple food. If enough plant species go extinct, I hope you don't require oxygen to survive. If the oceans are depleted of sweet, delicate life, then just masturbate twenty times and put a bullet in your own head, because that would be preferable than the excruciating end to a ruined world.
If, however, more urgent matters are pressing you than the rapid eradication of many species (possibly even your own), such as paying bills, family crisis, or running your multi-national oil corporation, then by all means ignore the rampant death and destruction all around you.
Extreme changes in weather have happened on Earth many times in the past, in the form of global superstorms, Ice Ages , desertification, volcanic activity, and vast methane clouds. Though incredibly adaptable, life still has its limits, and can't be reasonably expected to morph from a tropical-dwelling, massive scaled meat-eater to a small, furry-coated omnivore in the span of three days. So far, the mass extinctions that gripped the planet essentially swept away the remnants of dinosaurs (literal and figurative) as a reshaped planet made way for population explosions of better-suited progenitors.
No matter how well-adapted to your environment you think you are, it's nigh-impossible to survive when the whole landscape is being hotly scarred by the fiery bombardment of country-sized rocks. Only by dwelling deep underground will there be any hope of survival for organisms larger than bacteria, spores and viruses. And even these will have to compete with the deadly alien strains hitchhiking along with the calamitous space bullets.
The Earth is pummeled by hundreds of tons of space rocks a year, but most of them burn up high in our atmosphere, producing shooting stars or spectacular meteor showers. Larger impacts, like the Chelyabinsk meteor that exploded over Russia last year, are much more rare, occurring every few decades or so. That space rock, which was about 20 meters in diameter, injured about 1,000 people, mostly from shattering glass from the shock of its impact. But as the Earth is more than 70 percent water, many meteors of this size strike the planet, but go unnoticed by us.
However, many asteroids have collided with Earth and have caused great damage in our recent geological history. The Chicxulub asteroid, which was about 10-15 kilometers wide, is believed to have caused the mass extinction of dinosaurs 66 million years ago when it landed in the northern Yucatán Peninsula. But what effect would a large asteroid of this size have on civilization today?
Astronomers scour our skies, keeping a vigil at night so we don’t have to. NASA has two programs actively searching for large asteroids, one called the Asteroid Initiative and the other the Near Earth Observation Program, also known as “Spaceguard.” The scientists who work for these programs say it would take an asteroid about a 10th the size of Chicxulub to wipe out humankind. Asteroids of this size strike the Earth on average once every half million years at best.
Recently, there have been many media reports of an asteroid, discovered by Ukrainian scientists, which has the potential to wipe out the planet in 2036. But while the asteroid, called 2013 TV135, will likely make a close pass, NASA researchers says their calculations show its chances of striking the Earth are under .0021%. So despite the dire warnings from the media, there is very little to worry about.
Still, NASA scientists are looking at technologies to divert such asteroids if they ever do pose a risk. The current ideas for shielding us from asteroids vary greatly. Two still being considered are blowing it to smithereens with a nuclear bomb, and gently pushing it off course with kinetic interceptors (possibly using nuclear bombs as well). While the first solution makes for better Hollywood, the consensus from scientists is that nudging a killer asteroid off course is the smarter alternative.
Solar Superstorm Edit
Astronomers agree that a giant storm on the surface of the sun will eventually cause a great calamity on Earth, but there’s doubt whether it will be enough to end humankind.
The probability of a solar superstorm big enough to wreak havoc on the planet is real. The chances of one having an impact on the Earth in the next decade is about 12% according to NASA scientists. And only two years ago, such a storm erupted from the sun's surface, but luckily the blast was not directed at us. Had it occurred a week earlier, it could have been one of the worst geomagnetic storms in more than 400 years, sending billions of tons of highly charged particles into the planet’s magnetic field and destroying electrical grids worldwide, for months or even years.
Some scientists speculate that near the end of the last Ice Age, there was a large solar superstorm that led to the sudden disappearance of many mammalian species. In a paper published in the journal Radiocarbon, Paul LaViolette, the controversial astrophysicist and founder of the Starburst Foundation, claims that a large solar flare, which occurred some 12,900 years ago, primarily led to the demise of mammals weighing between 55 and 110 pounds.
NASA says the intense bursts of electromagnetic energy and particles showering the Earth from a solar storm caused by a coronal mass ejection are not physically capable of destroying Earth or its inhabitants, but they could shut down everything from cellphones to air travel. NASA and the National Oceanic and Atmospheric Administration Space Weather Prediction Center, which monitors “solar weather,” say that the sun’s superstorms can be predicted and they can issue warnings to electric utilities, spacecraft operators and airline pilots before a coronal mass ejection makes its way to Earth. Electrical and electronic systems can be shut down during the storm and turned back on when the storm subsides. We could actually wait out a solar superstorm the same way coastal communities wait out hurricanes. When it’s over we’ll be able to resume our lives — even if they are greatly altered — conclude many scientists.
Often, the unexpected and untimely end of a species is due to no fault of their own. One can hardly be blamed for not being born comet-proof, or expected to evade an invasive deadly species never encountered before in your history. And then there are animals so pathetic, so piss-poor and woefully dismal in their evolutionary niche that one can't help but blame the victim. Stubby, malformed wings, slow and dumb-witted naivete, inbred and disease-rich, low birthrate-having, highly specialized to the point of self-defeating, certain creatures have an anatomy and/or behavior pattern that is just asking for it. If your entire survival strategy hinges on good times and plenty, and with the least adversity you all just throw yourselves against the sharp rocks, or onto the plates of carnivores, then just go do what so many internet commenters advise you to do; what you were born to do -- just die.
Evolution is a lot of pressure, and basically becomes an arms race between the many levels of eatery. Plants develop toxins, so herbivores develop immunity to those toxins. Herbivores breed faster offspring, so carnivores must become even faster. Hooves bash in soft skulls, jaws clamp down on exposed necks, hard shells prevent sharp claws, long fangs protrude through brain stems, parasites take over hosts, poisons infect unwary attacks, and brains develop strategy over brawn. Ultimately, apex predators evolve and dominate all others, sometimes too well.
Perfectly designed killing machines, cats are responsible for the expirations of countless insects, rodents, birds, lizards, fish and various other creatures. Once introduced into new environs and climes by human slaves, cats conquered the globe with little thought to the devastation wreaked in their fat wake.
see also; Robot War For the Future
There is no reason to think that intelligence itself will make something behave nice and morally. In fact, it is possible to prove that certain types of superintelligent systems would not obey moral rules even if they were true.
Even more worrying is that in trying to explain things to an artificial intelligence we run into profound practical and philosophical problems. Human values are diffuse, complex things that we are not good at expressing, and even if we could do that we might not understand all the implications of what we wish for.
Software-based intelligence may very quickly go from below human to frighteningly powerful. The reason is that it may scale in different ways from biological intelligence: it can run faster on faster computers, parts can be distributed on more computers, different versions tested and updated on the fly, new algorithms incorporated that give a jump in performance.
It has been proposed that an “intelligence explosion” is possible when software becomes good enough at making better software. Should such a jump occur there would be a large difference in potential power between the smart system (or the people telling it what to do) and the rest of the world. This has clear potential for disaster if the goals are badly set.
The unusual thing about superintelligence is that we do not know if rapid and powerful intelligence explosions are possible: maybe our current civilisation as a whole is improving itself at the fastest possible rate. But there are good reasons to think that some technologies may speed things up far faster than current societies can handle. Similarly we do not have a good grip on just how dangerous different forms of superintelligence would be, or what mitigation strategies would actually work. It is very hard to reason about future technology we do not yet have, or intelligences greater than ourselves. Of the risks on this list, this is the one most likely to either be massive or just a mirage.
Yet another potential impact of a warmer planet has been discovered: ancient viruses being brought back to life as a result of melting ice.
This possible risk was discovered in Siberia, where scientists found a 30,000-year-old virus that became exposed in the melting permafrost.
“This is the first time we’ve seen a virus that’s still infectious after this length of time,” Professor Jean-Michel Claverie of the National Center for Scientific Research at the University of Aix-Marseillein France told the BBC News. Claverie is one of the authors of a study that details the scientific discovery.
Known as Pithovirus sibericum, the contagion is a “giant” virus (1.5 micrometers)—the largest ever found in fact, and can be seen under a microscope (unlike most viruses).
The discovery serves as a warning about buried viruses that may become exposed to the atmosphere when global warming causes frozen tundra to thaw.
Accounting for most extinctions of any other cause (and indeed, most of the other causes listed previously), humans are magical idiot apes good for not much else than destruction. One could even say that their ability to drive other species extinct even reaches epic or Awesome proportions.
According to a team led by Stuart Pimm of Duke University in Durham, North Carolina, human activities are driving species to extinction at roughly 1000 times the background rate, i.e. the rate at which species would die out in the absence of humans. Humans have caused 322 animal extinctions over the past 500 years, with two-thirds of those occurring in the last two centuries.
Some cataclysmic events would be so devastating as to cause the massive extinction of every living organism on a global scale.
While only two nuclear weapons have been used in war so far – at Hiroshima and Nagasaki in World War II – and nuclear stockpiles are down from their the peak they reached in the Cold War, it is a mistake to think that nuclear war is impossible. In fact, it might not be improbable.
The Cuban Missile crisis was very close to turning nuclear. If we assume one such event every 69 years and a one in three chance that it might go all the way to being nuclear war, the chance of such a catastrophe increases to about one in 200 per year.
Worse still, the Cuban Missile crisis was only the most well-known case. The history of Soviet-US nuclear deterrence is full of close calls and dangerous mistakes. The actual probability has changed depending on international tensions, but it seems implausible that the chances would be much lower than one in 1000 per year.
A full-scale nuclear war between major powers would kill hundreds of millions of people directly or through the near aftermath – an unimaginable disaster. But that is not enough to make it an existential risk.
Similarly the hazards of fallout are often exaggerated – potentially deadly locally, but globally a relatively limited problem. Cobalt bombs were proposed as a hypothetical doomsday weapon that would kill everybody with fallout, but are in practice hard and expensive to build. And they are physically just barely possible.
The real threat is nuclear winter – that is, soot lofted into the stratosphere causing a multi-year cooling and drying of the world. Modern climate simulations show that it could preclude agriculture across much of the world for years. If this scenario occurs billions would starve, leaving only scattered survivors that might be picked off by other threats such as disease. The main uncertainty is how the soot would behave: depending on the kind of soot the outcomes may be very different, and we currently have no good ways of estimating this.
The big problem is not the infamous “grey goo” of self-replicating nanomachines eating everything. That would require clever design for this very purpose. It is tough to make a machine replicate: biology is much better at it, by default. Maybe some maniac would eventually succeed, but there are plenty of more low-hanging fruits on the destructive technology tree.
The most obvious risk is that atomically precise manufacturing looks ideal for rapid, cheap manufacturing of things like weapons. In a world where any government could “print” large amounts of autonomous or semi-autonomous weapons (including facilities to make even more) arms races could become very fast – and hence unstable, since doing a first strike before the enemy gets a too large advantage might be tempting.
Weapons can also be small, precision things: a “smart poison” that acts like a nerve gas but seeks out victims, or ubiquitous “gnatbot” surveillance systems for keeping populations obedient seems entirely possible. Also, there might be ways of getting nuclear proliferation and climate engineering into the hands of anybody who wants it.
We cannot judge the likelihood of existential risk from future nanotechnology, but it looks like it could be potentially disruptive just because it can give us whatever we wish for.
if it was good enough for the dinosaurs
Considering its relatively diminutive size, Mercury poses the greatest risk of disturbing the present order of the solar system. In 2008, two simulations of long-term planetary movement revealed that Mercury’s orbit could become unstable by the gravitational pull of Jupiter, causing it to move away from the sun and into a collision course with the Earth.
The studies, one at the Paris Observatory and the other at UC Santa Cruz concurred that there is about a 1% chance Mercury's orbit, which is already notably odd, could become unstable sometime during the lifespan of our sun. Numerous simulations based on this theory produced four major outcomes, with Mercury either colliding into the Sun, Venus, or Earth, or being flung from the solar system altogether without inflicting any damage.
No doubt, if a planet the size of Mercury crashed into the Earth, all life here would be annihilated. However the chances of this scenario playing out are exceedingly slim, say scientists. In fact, their simulations indicate a 99% chance that the planets will stay in their current orbits for the next 5 billion years, and by that time the sun will have expanded into a red giant star, swallowing up the innermost four planets.
...it's also probable that entire star systems or galaxies will eventually collide with this one, though you'll probably be long dead by then so who gives a fuck?
Dark Nebula Edit
In addition to being a cool band name, a dark nebula is a great cloud of cosmic dust, which is likely many times larger than the solar system. If the solar system were to pass through a nebula, it could obscure the light from the sun and the stars.
The European Space Agency’s Ulysses spacecraft has shown that the kind of galactic dust that’s found in dark nebulae is passing through our solar system more than normal, but that doesn't necessarily mean we're passing through a dark nebula. So far, the sun’s magnetic field has been able to shield the planet from most of this stardust, but recent studies have shown that it's losing its protective power, so about three times more dust than usual is now passing through the solar system at a very high rate.
It’s conceivable that an increase in the amount of dust in the solar system will create more cosmic dust as it impacts asteroids and comets, say researchers, which adds to the extraterrestrial material that rains down on Earth. Some scientists speculate that a great amount dust entering in the solar system and Earth’s atmosphere could conceivably create a “nebula winter” or a great environmental catastrophe with various forces acting to cool the planet, destroy the ozone layer and deplete it of oxygen.
These researchers theorize that nebula winters are behind Earth’s repeated Ice Ages and mass extinctions. The phenomenon is sometimes called “snowball Earth” and eons-old supernovae and star bursts are claimed to be the culprits behind the nebulae that move throughout the galaxy.
Natural pandemics have killed more people than wars. However, natural pandemics are unlikely to be existential threats: there are usually some people resistant to the pathogen, and the offspring of survivors would be more resistant. Evolution also does not favor parasites that wipe out their hosts, which is why syphilis went from a virulent killer to a chronic disease as it spread in Europe.
Unfortunately we can now make diseases nastier. One of the more famous examples is how the introduction of an extra gene in mousepox – the mouse version of smallpox – made it far more lethal and able to infect vaccinated individuals. Recent work on bird flu has demonstrated that the contagiousness of a disease can be deliberately boosted.
Most work on bioweapons have been done by governments looking for something controllable, because wiping out humanity is not militarily useful. But there are always some people who might want to do things because they can. Others have higher purposes. For instance, the Aum Shinrikyo cult tried to hasten the apocalypse using bioweapons beside their more successful nerve gas attack. Some people think the Earth would be better off without humans, and so on.
The number of fatalities from bioweapon and epidemic outbreaks attacks looks like it has apower-law distribution – most attacks have few victims, but a few kill many. Given current numbers the risk of a global pandemic from bioterrorism seems very small. But this is just bioterrorism: governments have killed far more people than terrorists with bioweapons (up to 400,000 may have died from the WWII Japanese biowar program). And as technology gets more powerful in the future nastier pathogens become easier to design.
Magnetic Pole ShiftEdit
If a star were to die in a nearby solar system, the resulting supernova explosion could come close enough to the Earth to have devastating effects on the biosphere. The gamma-ray radiation would have the most deadly impact by depleting the Earth’s ozone layer enough to expose us to harmful solar and cosmic radiation. The first lifeforms that would die off would be the ocean’s phytoplankton and then famine and pestilence would move up the food chain. Eventually, we would meet our demise through starvation, if the radiation doesn’t kill us first.
On average, a supernova explosion occurs within 33 light years of the Earth every 240 million years and scientists say it would take an event some 25 light years away to significantly deplete the Earth’s ozone layer. Astronomers, however, have a good idea which stars are on their way to becoming supernovas. One prominent candidate nearby is the red giant Betelgeuse. But at 643 light years, a supernova event on that star wouldn’t have deadly impact here. However, it might make for a beautiful evening sky spectacle.
More worrisome are white dwarf stars, which are much more unpredictable. It would take a supernova from a white dwarf no more than 25-35 light years away to have a devastating impact here. The closest known white dwarf which is a candidate is IK Pegasi, but astronomers say its velocity relative to our solar system make it less of a threat every day as it moves a safe distance away.