What would be humanity's likeliest demise?

[Nibb31]

Evolution.

[PB666]

4 hours ago, KSK said:

Overpopulation and climate change leading to inadequate food and water security, followed by warfare to secure what resources are left, followed by some suitably desperate nation kicking things off with a nuke. Probably wouldn't kill off all of humanity but living in whatever's left wouldn't be a lot of fun.

Edit: In a probably vain attempt to keep this on track, I refuse to speculate on the root causes of said climate change.

Atomic weapons killed 150,000

Greed&Overpopulation&Ignorance will kill billions.

Where from civilization erupts a plague that spreads,
each cure morphs a beast with even more heads.

[cantab]

Any of the options given could destroy modern civilization. None would destroy humanity outright immediately. But if and when we are blown back to the Stone Age, well we can't rebuild. A lot of the stuff used in history to build our civilization and technology is gone. Easy-to-get ores, vast temperate woodlands, and so on. Humanity would never recover from a sufficiently global disaster, and we would limp on before dwindling and dying to the everyday threats of nature.

[fredinno]

17 minutes ago, cantab said:

Any of the options given could destroy modern civilization. None would destroy humanity outright immediately. But if and when we are blown back to the Stone Age, well we can't rebuild. A lot of the stuff used in history to build our civilization and technology is gone. Easy-to-get ores, vast temperate woodlands, and so on. Humanity would never recover from a sufficiently global disaster, and we would limp on before dwindling and dying to the everyday threats of nature.

But we should have much of the information left, if we keep libraries.

[PB666]

38 minutes ago, fredinno said:

But we should have much of the information left, if we keep libraries.

During the dark ages the libraries were the first to go. Remember the library of Alexandria. Non-compliant information is a threat to the power of those enforcing ignorance. When a zero sum game collapses, the demagogues and autocrats rely on ignorance to keep them at the top of the pyramid. The shrinking game, the powerful can only stay powerful if they take more from the bottom. 

[Bill Phil]

5 hours ago, Darnok said:

1. But we had epidemics in Europe, so we will survive, don't worry.

2. USA over 50% global pollution, if you count in all their industry located outside of their borders.

3. Because our industry is developed in wrong direction. We should produce less products, but they should be more durable. It would cut resource, space and energy consumption of global industry.

 

 

But those 15000 liters is not send to space, it is still on Earth. Also if you watched video I posted you should blame overweighted people for that, they eat too much.

No, it just takes that much water to make a kilogram of beef, overweight people are irrelevant to that. You have to grow food for the animals, and provide water to them, and a bunch of other things. Also, there are thin people who eat more than overweight people. Overweight people are overweight for different reasons than just overeating. They may eat as much as anyone else does or less, but they may have a slow metabolism.

The water does stay in the water cycle, but some of it is lost.

51 minutes ago, PB666 said:

During the dark ages the libraries were the first to go. Remember the library of Alexandria. Non-compliant information is a threat to the power of those enforcing ignorance. When a zero sum game collapses, the demagogues and autocrats rely on ignorance to keep them at the top of the pyramid. The shrinking game, the powerful can only stay powerful if they take more from the bottom. 

The church library and the libraries in the Muslim empires were spared somewhat.

Edited March 30, 2016 by Bill Phil

[Findthepin1]

We're going to venture out into space, to other planets and stuff, for a long time. Like colonies and stuff. Those will all(?) die for a variety of reasons. There will be a few ships that are supposed to be 100% efficient. Those will probably last until the point at which humans on Earth all die out, and maybe some time after, but not forever, as detailed in the next paragraph. You see, everyone on Earth is getting more and more powerful with each new invention. Look at us today. The late 2010s. Compare today to the late 1910s. Compare it to the 1500s. Compare it to the 11500s BC. Everyone has access to more and more physical power as time goes on. That includes those who oppose mainstream human society. Can you imagine, a thousand years from now, a bunch of extremely mainstream-human-society-opposing people (not gonna write the word here because I don't want to end up on some crime watchlist) explode the Moon or something, or change Mars' orbit so that it will hit Earth? You see, even the bad people. I predict that in less than two hundred years, someone is gonna send a large asteroid to hit Earth. They'd be just like today's extremely mainstream-human-society-opposing people possessing "objects of mass wrecking" (again, crime watchlists). And there won't be anything we can do about it. That's why we won't last very long on Earth.

There are always the people in space. Nope. Not always. There is almost no life on Earth designed to last centuries or millennia in an enclosed space. Either way, there will be no machines that can maintain a friendly environment for centuries or millennia, you need a planet for that, and given the circumstances, I doubt there would be one. If we send a starship to any other star, it will probably not make the journey without problems, and if it does, it can't seed another planet effectively enough. If you want to make a stable environment for life to survive for geologic timescales, I suspect you need every single living thing from the original environment to be there for a copy of it to be effective. We can't do that. DNA will not last the time it takes to get to another star, even without the obvious pummelling by cosmic rays and such.

Back to Earth, even if there are no catastrophic intentional destroyings (yet again, an euphemism because I don't want to end up on crime watchlists), there are problems with overpopulation, and garbage, and food, etc. We keep filling up land with farms, and then eventually, people. If a little land gets covered up by glaciers in a cooling event, this won't stop anything, sea levels will have fallen and more land will be available for farms and eventually people. If a little land is lost to the sea in a warming event, this won't stop anything either, it's worse. There's a whole continent that would've just opened up to farms and eventually people. First, people cover all the available land with farms. They'll proceed to urbanizing it. Then high-rising it. We now face a problem. As more and more farmland on Earth is replaced by cities, there're more and more people and less and less to feed them. There will be riots and revolutions. And they're not going to change a thing. Most people are going to starve to death. The ones who have water and food won't die out. Yet.

What's happening to all the garbage? It's being either put underground or into the oceans. Excavating is expensive, so it's probably the latter. The oceans become dead. Nothing can live in them. Not even sea plants or algae. And that is Earth's next problem. Those marine lifeforms produce about 70% of Earth's atmospheric O2. We lose them, we lose about 70% of Earth's atmospheric O2. We can't breathe 6% oxygen. Especially not with so much other stuff in the air, stuff from our garbage, stuff we've emitted with machines, stuff the dead stuff has emitted, etc. In terms of composition, Earth's atmosphere is going to look more like Titan's does today. Lots of nitrogen, some methane and oxygen. As most of us know, methane mixed with oxygen is bad. Like, inside-a-rocket-engine bad. Whatever survived the disappearance of most of the atmospheric O2, the poisoning of the oceans (and therefore the precipitation, and therefore most rivers and lakes and usable water) is not going to survive being burnt to a crisp in the next lightning storm and poof, suddenly the atmosphere's on fire over a quarter of the planet. This will boil water in some of these areas. Making clouds. Generating more thunderstorms.

The oceans are gonna be mostly gone eventually because of this. The surface temperature is gonna be like a hundred degrees Celsius. An atmosphere of nitrogen and water vapour, a small bit of oxygen, maybe about as much carbon dioxide, a bit of methane in there. You can only survive if you are an anaerobic deep-sea microbe living in the Arctic Ocean. Things will cool down in the next few million years, but life on Earth will be starting with microbes and is going to have a billion or less years to live because of the Sun. Not enough time to evolve into anything large.

TL;DR: Everything you can think of is probably going to have some impact, I don't think our species will get through the next ten thousand years, and life on Earth is very, very, very close to its near-end from which it can never fully recover before it definitely dies.

Edited March 31, 2016 by Findthepin1
n

[Frozen_Heart]

I can't really see much that could wipe out humanity atm apart from either cosmic threats or we evolve and or no longer 'human'.

Other things on the list could maybe kill 99%, but some would survive and start it all again.

[daniel l.]

I would like to think that we wont die out, We become sufficiently paranoid of the risks that we do everything we can to avoid them, I'd like to believe that we will avoid natural disasters by becoming a multi planet species, Death will no longer exist because of new medical procedures and digital transcendence, And ultimately we will if there has to be an end we will alter ourselves beyond the point that we could be called human, But will we die out in a tragic manner? I dont think so.

Edited March 31, 2016 by daniel l.

[Dfthu]

Kim Jong Un and his nukes.

Edited March 31, 2016 by Dfthu

[magnemoe]

Well global warming/ vulkanisme and nuclear war is pretty similar here in causing widespread destruction and might easy end civilization, however its not something who would kill all humans as we are everywhere on the planet.

Disease don't make widespread species extinct. Alien invasion is unlikely if they want the planet they should be here already. 
Note that you might be able to create an more devastating disease however some idiots is likely to try to use biological weapons before this so we have defenses. 
Uplifting an species like cats who then replace us is more likely than alien invasion. 

AI far more likely, might not even be hostile just that the matrix is more fun than real life. You see traces of this already. 

Cosmic threats is an option, not so much impact as galactic events like supernovas. 

Most likely we get replaced by an mix of genetic modified humans and AI over an long time.
----
Saw an comic once, very old man on heavy life suport in an sci-fi hospital room surrounded by robot nurses and doctors. 
Man died and the doctors reported this and the robots celebrated as he was the last man alive.

6 hours ago, cantab said:

Any of the options given could destroy modern civilization. None would destroy humanity outright immediately. But if and when we are blown back to the Stone Age, well we can't rebuild. A lot of the stuff used in history to build our civilization and technology is gone. Easy-to-get ores, vast temperate woodlands, and so on. Humanity would never recover from a sufficiently global disaster, and we would limp on before dwindling and dying to the everyday threats of nature.

Only thing we will miss is easy to get oil so we is likely to have to go directly from steam to electricity.
We will have loads of metal with all the junk around including hard to make stuff like aluminium and titanium. 
Its the last 150 years who is hard to rebuild everything before is easy if you know how.

[Bill Phil]

6 hours ago, cantab said:

Any of the options given could destroy modern civilization. None would destroy humanity outright immediately. But if and when we are blown back to the Stone Age, well we can't rebuild. A lot of the stuff used in history to build our civilization and technology is gone. Easy-to-get ores, vast temperate woodlands, and so on. Humanity would never recover from a sufficiently global disaster, and we would limp on before dwindling and dying to the everyday threats of nature.

We would continue to evolve, or devolve, but if we can retain some knowledge, enough knowledge, civilization can be rebuilt. Civilization like the ancient ones, but still civilization. But only a small number of people could advance to our technology, and even then slowly. 

Wood is extremely versatile, and it's pretty easy to grow. You can make structures, fires, charcoal, woodgas, paper, and probably a bunch of other things. We could use wood farms to mass produce charcoal and then use that to gasify wood, which can then be used to make methane or something else. If we can retain metallurgy and the knowledge of wood's versatility, we can manage. 

But even that methane would only give us a higher energy density than wood and charcoal, and it would take a lot of wood to make sufficient methane. But eventually you could use the methane for something.

Edited March 31, 2016 by Bill Phil

[kerbiloid]

It's hard to degrade below XIX century, as the industrial revolution was mostly made by hands.

Edited March 31, 2016 by kerbiloid

[Darnok]

8 hours ago, PB666 said:

During the dark ages the libraries were the first to go. Remember the library of Alexandria. Non-compliant information is a threat to the power of those enforcing ignorance. When a zero sum game collapses, the demagogues and autocrats rely on ignorance to keep them at the top of the pyramid. The shrinking game, the powerful can only stay powerful if they take more from the bottom. 

"troops of Caesar accidentally burned the library down during or after the Siege of Alexandria in 48 BC"
https://en.wikipedia.org/wiki/Destruction_of_the_Library_of_Alexandria

[fredinno]

6 hours ago, Findthepin1 said:

Back to Earth, even if there are no catastrophic intentional destroyings (yet again, an euphemism because I don't want to end up on crime watchlists), there are problems with overpopulation, and garbage, and food, etc. We keep filling up land with farms, and then eventually, people. If a little land gets covered up by glaciers in a cooling event, this won't stop anything, sea levels will have fallen and more land will be available for farms and eventually people. If a little land is lost to the sea in a warming event, this won't stop anything either, it's worse. There's a whole continent that would've just opened up to farms and eventually people. First, people cover all the available land with farms. They'll proceed to urbanizing it. Then high-rising it. We now face a problem. As more and more farmland on Earth is replaced by cities, there're more and more people and less and less to feed them. There will be riots and revolutions. And they're not going to change a thing. Most people are going to starve to death. The ones who have water and food won't die out. Yet.

The scenario of the world being taken over by cities sounds like Earth turning into an IRL Coruscant...

http://starwars.wikia.com/wiki/Coruscant

But seriously, though, cooling events cause there to be less rain due to less evaporation (and thus less fresh water to irrigate farms) while warming events create more rain (but does not always mean smaller deserts)

But people will eventually desalinate water, and build vertical farms once construction processes get cheap enough... https://en.wikipedia.org/wiki/Vertical_farming

thus nhilling the food and water problems. Topsoil is a little more difficult, but we could probably use the things we use to create artificial fertilizer (phosphorous mines, ammonia production refineries, etc), provided the resource feedstock is from space.

I'm more worried about other resources, but the vast human population could make a manufacturing economy there, as long as you have a cheap way to access space. Sort of like how Japan managed to become so economically powerful despite lacking resources.

6 hours ago, Findthepin1 said:

 

What's happening to all the garbage? It's being either put underground or into the oceans. Excavating is expensive, so it's probably the latter. The oceans become dead. Nothing can live in them. Not even sea plants or algae. And that is Earth's next problem. Those marine lifeforms produce about 70% of Earth's atmospheric O2. We lose them, we lose about 70% of Earth's atmospheric O2. We can't breathe 6% oxygen. Especially not with so much other stuff in the air, stuff from our garbage, stuff we've emitted with machines, stuff the dead stuff has emitted, etc. In terms of composition, Earth's atmosphere is going to look more like Titan's does today. Lots of nitrogen, some methane and oxygen. As most of us know, methane mixed with oxygen is bad. Like, inside-a-rocket-engine bad. Whatever survived the disappearance of most of the atmospheric O2, the poisoning of the oceans (and therefore the precipitation, and therefore most rivers and lakes and usable water) is not going to survive being burnt to a crisp in the next lightning storm and poof, suddenly the atmosphere's on fire over a quarter of the planet. This will boil water in some of these areas. Making clouds. Generating more thunderstorms.

You can dump them in old mines.

Earth will also lack resources at this point, so recycling garbage will become more profitable.

And methane is a great energy source, and landfills are great sources of them.

No to mention, if things get this bad environmentally, and civilization is still intact, I am fairly sure people will try to clean things up, like smog in 60s America, and today's China. And global warming is different, suffocating to death is a lot more apparent than the slow and steady change of a climate.

6 hours ago, Findthepin1 said:

The oceans are gonna be mostly gone eventually because of this. The surface temperature is gonna be like a hundred degrees Celsius. An atmosphere of nitrogen and water vapour, a small bit of oxygen, maybe about as much carbon dioxide, a bit of methane in there. You can only survive if you are an anaerobic deep-sea microbe living in the Arctic Ocean. Things will cool down in the next few million years, but life on Earth will be starting with microbes and is going to have a billion or less years to live because of the Sun. Not enough time to evolve into anything large.

What? I would expect at least hardy, fast evolving plants like Algae and Lichen would survive...

Not to mention bugs, insects, possibly rats and cockroaches, which can adapt quickly.

3 hours ago, Dfthu said:

Kim Jong Un and his nukes.

Said no one ever.

 

[Nuke]

i have a problem imagining things like nuclear war climate change or pandemics to cause total annihilation of the human race. they might make survival very difficult for a time, but then humans would eventually adapt and come out ahead. pandemics in particular would stimulate human evolution, as survivers would have a new found immunity to the desease that almost wiped them out. ai may actually be seen as an evolution of our own species beyond its biological limits, our culture and history would be passed on to our robotic successors. aliens might have an interest in preserving biodiversity and keep a small population alive. this process of elimination leaves us with cosmic threats.

if humans get planet locked, they could easily die when the sun expands, and depletion of planetary resources may eventually restrict population size to a fraction of its current size. some kind of gamma ray event could sterilize the planet instantly. orbital interactions may push the earth out of the habitable zone and we freeze to death or cook. you got good old asteroid strikes which might take out our species (some may survive through extreme measures). so yea, i have to vote cosmic.

if we somehow manage to escape the death of earth, we would still have to contend with the grim nature of thermodynamics. we may vary well die with the universe.

Edited March 31, 2016 by Nuke

[WinkAllKerb'']

*crappy pun mode on*

humanity is going to be enslaved by evolution wich is enslaved by evolution wich is enslaved by evolution wich is enslaved by evolution

so far no one voted for slavery ? weird

make an effort, peoples slavery need love too xDr

*crappy pun mode off*

Edited March 31, 2016 by WinkAllKerb''

[magnemoe]

2 hours ago, Darnok said:

"troops of Caesar accidentally burned the library down during or after the Siege of Alexandria in 48 BC"
https://en.wikipedia.org/wiki/Destruction_of_the_Library_of_Alexandria

Note that it was very easy to destroy knowledge back in ancient times as the centers with knowledge was small and it was very few copies of most books. 
This also applies to other knowledge of more practical art, we do not know how they build the pyramids as we found no documentation. 

Easier to preserver things today as its so many copies, however its an problem that so much is stored on disks and chips or far worse in the cloud.
 

[kerbiloid]

Also ancient people didn't know about firearms, cars and military abilities which they give.
So, any cataclysm will first of all force the efforts to repair industrial technologies required to make your own tank and a dump-truck with drums against neighbor tribes.
Which also means later XIX century.
 

Edited March 31, 2016 by kerbiloid

[PB666]

2 hours ago, magnemoe said:

Note that it was very easy to destroy knowledge back in ancient times as the centers with knowledge was small and it was very few copies of most books. 
This also applies to other knowledge of more practical art, we do not know how they build the pyramids as we found no documentation. 

Easier to preserver things today as its so many copies, however its an problem that so much is stored on disks and chips or far worse in the cloud.
 

Yeah there are no centralized stores of knowledge now, its not like we store stuff in the clouds.

 

 

 

:^).

Edited March 31, 2016 by PB666

[Bill Phil]

6 hours ago, kerbiloid said:

It's hard to degrade below XIX century, as the industrial revolution was mostly made by hands.

Can you make a steam engine? Yeah you can look it up, and you could potentially do trial and error with your current knowledge. But the average isn't likely to know how to build one. Not only that but all the easy coal has been mined.

[pyrosheep]

I Think people will find a way to upload themselves into machines and live in a simulated reality, a technological rapture if you will.  

Edited March 31, 2016 by pyrosheep

[kerbiloid]

Myself - no. Any technology needs some minimum amount of people to be used.

But early XIX century people worked using hammer, plough and other primitive hand instruments. And as you can see, 40 years later there was a steampunk age.
But 40 years before they had no idea about all that technologies. Now, what about tell early XIX people what are steam and diesel machines, how to construct and use them?

Now there are hudred millions of mechanics and engineers, billions of engineering books, millions of cars and steam machines and mountains of instruments.
It's clear what to do, it's more or less clear - how, there's no need to start with brimstone.
Several years until somebody establishes a leadership over enough large region and mobilize people to gather the machine remains and to build primitive plants - and a score years later there would be a state on the later XIX century TechLevel.

Edited March 31, 2016 by kerbiloid

[Bill Phil]

1 minute ago, kerbiloid said:

Myself - no. Any technology needs some minimum amount of people to be used.

But early XIX century people worked using hammer, plough and other primitive hand instruments. And as you can see, 40 years later there was a steampunk age.
But 40 years before they had no idea about all that technologies. Now, what about tell early XIX people what are steam and diesel machines, how to construct and use them?

Now there are hudred millions of mechanics and engineers, billions of engineering books, millions of cars and steam machines and mountains of instruments.
It's clear what to do, it's more or less clear - how, there's no need to start with brimstone.
Several years until somebody establish a leadership over enough large region and mobilize people to gather the machine remains and to build primitive plants - and a score years later there would be a state on the later XIX century TechLevel.

But you're forgetting that they had a bunch of pretty big industrial nations. The British Empire is where the industrial revolution started.

The average person would continue to work with their own hands or an animal's for quite some time. But the industrial revolution used machines in conjunction with hand labour. 

[pyrosheep]

9 minutes ago, Bill Phil said:

Can you make a steam engine? Yeah you can look it up, and you could potentially do trial and error with your current knowledge. But the average isn't likely to know how to build one. Not only that but all the easy coal has been mined.

You can basically use anything that burns hot enough to boil water to run a steam engine, people mostly used coal because it has better energy density than wood.

In places were wood was much cheaper than coal, wood was used instead of coal.

This steam engine used wood as you can tell from it's spark arresting funnel.