9 ms·

If true, that ends up meaning that alien civilizations are short-lived, right? That doesn't bode well for us.

by kadoban 5y ago

hashkb 5y ago
We're on a steady path to extinction, no doubt.
- throw1234651234 5y ago
  Generalization. Would be interesting discussion with details. Pop is growing. What's your concern - global warming, fertility rates, pollution, nuclear arsenal, running out of resources? Doesn't seem like we are doing that badly and that pop can't drop if get below renewable resource level or adjust to new ways of making energy/food, etc. Does seem likely that on an extremely long time scale, we need to get multi-planetary, which is "realistic" if we give a reasonable time frame of, say, 10,000 years. As far as the sun dying, that's beyond even parent point's timeline. This is very things start to get questionable if we never get to even .1 of c (e.g. Project Orion "realistic" estimates). Alpha Centauri is relative close at 4.something ly, but other "potentially habitable/useful" star systems are way out there.
  - sha256kira 5y ago
    Agreed. The great filter and collapse theory in general are fascinating in theory and can motivate some great positive action but they can't undermine the fact that humans beings are doing better than they've ever done in our history by almost every imaginable metric.
    - amanaplanacanal 5y ago
      Plus humans are extremely adaptable. Even before we invented agriculture, people had colonized the whole planet, except for Antarctica. It would be hard to kill us all off.
      - not_jd_salinger 5y ago
        > humans are extremely adaptable This is a strange claim I see repeated over and over, but it has very little evidence to justify it. The only piece of evidence people present is: > people had colonized the whole planet, except for Antarctica This is true of a fairly large number of organisms on Earth. On top of this humans have only been around for ~200,000 years, that's not long at all. Humans have not survived a single mass extinction event. So far we've seen humans travel around a planet that has been relatively stable for that period of time. There have been plenty of species that have traveled around with us that didn't even need to rely on extra tools, clothing or the use of energy to survive. Humans share several vulnerabilities with other megafauna that have all gone extinct. A major one is a fairly long gestation, plus small number of offspring per generation. Human young likewise need tremendous amounts of care and energy to raise to mature adulthood. Additionally human have fairly high energy requirements to support their complex brains. We've seen exponential rise in human population only because humans have had access to excessive amount of non-renewable, high-energy density sources of energy. It just happens that humans have lived on a planet that has mostly been within survivable temperature changes, with historic climate changes happening on time scales that lead to easy migration. As you pointed out, the one continent that does not have an environment that supports human life remains empty. Humans can't survive a wet bulb temperature of 35C. Until just recently we never saw that temperature on this planet. As we see more and more places reach that temperature more often, I suspect we'll see how frail human adaptability is.
        edgyquant 5y ago
        > his is true of a fairly large number of organisms on Earth Is it though? How many other large, multicellular, organisms live on every continent without humans having brought them there?
        zabzonk 5y ago
        Seals. Birds.
        5y ago
    - not_jd_salinger 5y ago
      > the fact that humans beings are doing better than they've ever done in our history by almost every imaginable metric. That's because we have had ready access to insanely abundant high-energy density source of energy. The non-fossil fuel supported carrying capacity of the planet for humans is estimated to be somewhere around 1 billion people. When the fuel runs out (if we don't cook ourselves first), that will collapse. It is nothing intrinsic about humans that have lead to our recent success, just access to lots of nearly free energy. edit: why the downvotes? Is there even anything controversial in these statements? HN's fear of bad news is getting out of hand.
      - myrmidon 5y ago
        What is your source for the 1 billion estimate? Because that seems completely, non-credibly *low* to me. I also strongly believe that we could cover all our energy needs with renewable sources within a few decades if we really wanted to (even assuming no significant advances in tech), and this seems mostly non-disputed to me (because that is literally what nation-states are currently planning/doing). > Is there even anything controversial in these statements? Yes. Your statements seem not credible to me and you cite no sources.
        not_jd_salinger 5y ago
        1 billion is a rough estimate based populations prior to the massive boom in the industrial revolution that saw massive changes in the way agriculture is done. It could easily be 2 billion or so, but definitely not 7.8 billion. You can see the population history here[0.] To see the powerful impact of fossil fuels on carrying capacity you'll notice there's an important inflection point around 1920-1930. This is because of the advent of the Haber process[1] which allows us to use fossil fuels to create nitrogen based fertilizers. Lest you doubt the impact of the Haber process just look at trends in corn yield per acre since then [2]. It's truly remarkable. Additional gains there are from other industrialized, fossil fuel driven agricultural process. The Haber process requires hydrocarbons. In the wikipedia article you can see that it consumes 3-5% of the worlds natural gas production and 1-2% of the global energy supply. We have completely disrupted the natural nitrogen cycle [4] and so would be unable to produce anywhere near as much food without fossil fuels. Because we have disrupted this cycle it's not even obvious that we could go back to a world of pre-fossil fuel agriculture. So those are just some bit of information about my claims but let's take a look at yours: > we could cover all our energy needs with renewable sources within a few decades if we really wanted to... this seems mostly non-disputed to me This is wildly disputed, and I don't know anyone who credibly believes this without invoking "magic" future technology. For starters we haven't replaced fossil fuels with "renewables" at all so far. We've just used them to supplement our energy needs. You can see here [4] that global fossil fuel consumption has continued to rise. Then it is important to separate electricity from the more general subject of energy. Currently only 20% of global energy usage is electricity generation [5]. So even if you replaced the entire grid with renewables over night you would still be missing the vast majority of energy demands. We currently have no viable pathway for renewable energy in transportation. Alice Friedman has more notes on this than I could ever fit in a comment [6]. Transportation inherently requires high energy density fuels, and outside of passenger vehicles, battery technology does not have the density required for industrial shipping. It worth looking at our national energy flows to get a good sense of just how little of the energy we use comes from renewables [7]. But even if we look just at the electrical grid, in the US, we have some very obvious problems with "all" our needs. As you probably know, wind and solar are intermittent power sources that requires fossil fuel powered "peaker" plants to provide energy in down times. This had two problems. One you need energy storage technology that we do not currently have (you cannot use grid scale lithium batters, pumped hydro has geological constraints, molten salts only work with concentrated solar, compressed air requires decommissioned oil field, etc). The other problem is that even if you had perfect storage you need to now more than double the total energy production so you can fill those batteries. The should be enough sources for you to get started, but I have feeling I'll still get down votes and "hand wavy" explanations of how it will all work out. 0. https://en.wikipedia.org/wiki/World_population#/media/File:World_population_v3.svg https://en.wikipedia.org/wiki/World_population#/media/File:W... 1. https://en.wikipedia.org/wiki/Haber_process https://en.wikipedia.org/wiki/Haber_process 2. https://www.agry.purdue.edu/ext/corn/news/timeless/YieldTrends.html https://www.agry.purdue.edu/ext/corn/news/timeless/YieldTren... 3. https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_cycle https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_c... 4. https://ourworldindata.org/grapher/global-energy-substitution?country=%7EOWID_WRL https://ourworldindata.org/grapher/global-energy-substitutio... 5. https://www.iea.org/reports/world-energy-outlook-2019/electricity https://www.iea.org/reports/world-energy-outlook-2019/electr... 6. https://www.resilience.org/resilience-author/alice-friedemann/ https://www.resilience.org/resilience-author/alice-friedeman... 7. https://flowcharts.llnl.gov/content/assets/images/charts/Energy/Energy_2020_United-States.png https://flowcharts.llnl.gov/content/assets/images/charts/Ene...
    - hashkb 5y ago
      Cooperation is the key metric I'm considering. It's becoming more critical that we learn to, and we are not even trying.
- beervirus 5y ago
  On a long enough time line, the survival rate for everyone drops to zero.
  - arthurcolle 5y ago
    I am Jack's existential dread
- delecti 5y ago
  Sure eventually, but there's no clear indication if that's 10 years away, 10 billion years away, or a mere technicality as our descendants evolve into something that counts as a separate species.
  - not_jd_salinger 5y ago
    We're currently undergoing the largest mass extinction event that will easily rank in the top 6 of life on this planet and could possibly compete with the end-permian. What makes you think we could possibly survive? Because we're the cause? Plenty of species in the past that have caused extinction events also perished. It seems far more questionable to assume we won't risk extinction in the geological near term. The parent is downvoted more out of existential fear rather than an honest assessment of the situation.
    - delecti 5y ago
      I think the parent comment was downvoted because it's not really contributing anything besides pessimism. As for us, I don't doubt the likelihood of a serious mass extinction, including possibly a severe drop in human population, but I can't see it being so severe as to cause an existential threat to us. No other species on this planet has had the ability to change the environment to suit it, or the ease of mobility to move where they can survive. Short of earth being entirely incompatible with complex life on the surface, I don't see humanity disappearing because of climate change.
      - hashkb 5y ago
        We need the pessimism. Irrational exuberance clearly doesn't work.
        delecti 5y ago
        I have never seen anything remotely resembling exuberance around climate change. Everything I've seen is either pessimism or denial.
chadwittman 5y ago
Read more about the Great Filter, it's probable it's ahead of us.
- riffraff 5y ago
  is it _probable_? AFA we know we've been insanely lucky up to this point (as earthling life we went past multiple mass extinctions, we got multi-cellular life, multiple brains iterations, a society which still didn't wipe itself out etc) What makes it more likely for the filter to be ahead of us rather than behind us?
  - caeril 5y ago
    Modern civilization is extremely dependent on fossil fuels. We've already passed peak conventional oil production, and we're now surviving on EXTRAORDINARY technical means of enhanced oil recovery. If we can't make the complete transition to renewables in the next thirty years, it's game over for a VERY long time. Future civilizations won't enjoy the benefit of Spindletop. Cheap energy sources won't be available near the surface of the crust for another > 50 million years. We won't go extinct, but it will be the 18th century for a very long time and nobody will leave this rock during that time. The Great Filter is right here, in front of us, in our lifetimes.
    - pdonis 5y ago
      > Cheap energy sources won't be available near the surface of the crust for another > 50 million years. Wrong. We already have one: nuclear energy.
      - caeril 5y ago
        That's a good point. It's pretty easy to construct and maintain fission reactors without fossil fuels. I bet enriching uranium was a snap in the 18th century, too. It will be even easier even getting to the enrichment phase in the future, with accessible ores about 30% as rich as they were when the nuclear age began. Looking forward to the fleet of electric concrete trucks carrying electrically-manufactured concrete loaded with batteries that were produced with lithium carbonate dug out of the ground by electric excavation rigs. All of this construction work will also not be disrupted by any social unrest resulting from 3 billion people starving to death because the Haber process no longer has enough cheap feedstock to sustain modern agricultural processes. Thanks for educating me.
Moodles 5y ago
Carl Sagan thought this, though he lived during the cold war so it's not surprising he did.
- hnbad 5y ago
  Considering where climate change is heading, it's surprising anyone doesn't think this.
  - Taylor_OD 5y ago
    I agree in our case but this wouldnt be universal. Life may thrive in very hot planets if their evolutionary track was different.
  - scarmig 5y ago
    Climate change is very real and worth addressing, but it's extremely unlikely to wipe out human civilization. It's just going to be costly and kill millions, not billions.
    - ses1984 5y ago
      Climate change by itself could be extremely unlikely to wipe out human civilization but it could be the catalyst that sets other events in motion like nuclear war.
    - darthrupert 5y ago
      Climate change doesn't have to directly kill us all. It could be the trigger to something else that does.
    - miltondts 5y ago
      Extremely unlikely to wipe out all humans. I agree. Current civilization, I'm not so sure. For the reasoning: https://www.youtube.com/watch?v=IESYMFtLIis https://www.youtube.com/watch?v=IESYMFtLIis
    - hnbad 5y ago
      Can you clarify what you mean by "millions"? The Syrian civil war is estimated to have killed just short of half a million people. The pandemic easily has a global death toll of roughly 4 million people so far. The Chalisa famine of 1783/1784 is estimated to have killed 11 million people. The Spanish flu killed at least 17 million people, though some of the more dramatizing estimates place it closer to 100 million. According to some researchers, climate change is already killing 100,000 a year[1]. So I assume you're not thinking of just seven or eight digits unless you're exceedingly optimistic. Climate change will make parts of the world inhabitable that are currently populated by humans. It will also result in crop failures, which will cause famines. In some cases formerly native crops will no longer be supported by the changing local climate or farmland may become completely unusable. Potable water will become harder to source. Water contamination is a source of many deadly diseases. Even if we assume most of the deaths will be concentrated in places like Africa or the Indian subcontinent, the global economy relies on these places for resources and cheap labor. People in ongoing climate catastrophes also don't tend to stay put and die in an orderly fashion, they become refugees or riot against their governments. Things can get politically messy even in the nations next door as humans tend to be uncomfortable with political chaos and mass deaths. But unlike the Spanish flu, or the potato famine, or COVID, climate change is not a temporary blip that happens and then goes away. If all the carriers of the plague have died, nobody dies from the plague unless they get infected handling the dead. Famines can starve millions to death but once there's another harvest the survivors have food again. Climate change isn't like that. If climate change creates a drought, that's not just a drought, that's now dry season and it will be dry season every year from now. There are currently 7.8 billion humans. There's absolutely no reason to believe climate change can't kill billions, especially once it's managed to kill the first hundreds of millions. Keep in mind that it's not about "addressing" climate change. It's not a moldy bathroom tile that you need to clean up or replace before the mold spreads everywhere. It's a fire our entire way of life is fueling every single day. We know what needs to be done to slow it down to survivable levels (or at least levels that are lethal for less than 1% of us) but we can't just pass legislation or appeal to personal responsibility to do that because it involves changes that would be economical suicide for anyone doing it alone. The world economy is playing a game of chicken with each other and nobody is bluffing. [1]: https://grist.org/climate/how-many-people-has-climate-change-killed-already/ https://grist.org/climate/how-many-people-has-climate-change...
bob33212 5y ago
Civilizations are only detectable for a short period of time. Once they understand physics, they no longer need radio waves or Dyson spheres or to travel through what we call spacetime.
- yreg 5y ago
  Why wouldn't they need megastructures and travel once they understood enough physics?
  - bob33212 5y ago
    Space and time may be emergent, we don't know, all we do know is that our current model of physics is missing something. Quantum Gravity for example and We don't know what happens inside a black hole either.
    - yreg 5y ago
      That’s a non-answer though. Do you mean they are guaranteed to discover another “realm” and move to it? Why? It might not be possible, no matter how much physics one knows. Or do you take the Fermi paradox itself as a proof of the solution?
      - bob33212 5y ago
        Yes, it seems that the Fermi paradox implies that other civs progress beyond what we consider signs of intelligent life. The great filter seems less likely as we get close to colonizing other planets, and then other solar systems.
        AnimalMuppet 5y ago
        I question your use of "implies" there. It implies no such thing. What you suggest is one possible answer, nothing more.
        5y ago
aetherson 5y ago
Short lived on those timescales, yes. But not necessarily short lived in terms of our perspective. If we imagine that in the last 5 billion years, there have been a good solid 10,000 post-industrial civilizations, and each of those civilizations has lasted 10,000 years (in the post-industrial stage where they're detectable), then that implies that of the last 5,000,000,000 years, 100,000,000 of them have been host to a post-industrial civilization: a given year has on average 0.02 currently present civilizations in it. Now, this hypothesis does probably imply that significantly interstellar civilizations are impossible, since it seems like if you've colonized say 20 stars, what disaster could possibly end your civilization? (I think the most likely scenario is that we're the only civilization ever to have developed in the Milky Way. Everything else seems like it assumes a lot of additional stuff.)
- miltondts 5y ago
  > if you've colonized say 20 stars, what disaster could possibly end your civilization? Unfortunately, war with another civilization.
  - aetherson 5y ago
    I mean, maybe. Honestly hard for me to imagine war actually going on between two interstellar civilizations. But even if it did, it seems like in 99% of all cases, that would leave at least one of the two civilizations still around. We're looking for explanations, in this hypothesis, that leave 98% of all time with no civilizations.
    - kadoban 5y ago
      Maybe war between two spacefaring civilizations is too "easy". eg something like: throwing asteroids at ~the speed of light is necessarily a cheap thing to do once you're at that level, and everyone just dies. Like if on Earth nukes were something everyone could cook up in their backyard in an afternoon, we'd all be gone pretty quick. Not sure that really makes any sense though.
      - 5y ago

If true, that ends up meaning that alien civilizations are short-lived, right? That doesn't bode well for us.

hashkb 5y ago

We're on a steady path to extinction, no doubt.

throw1234651234 5y ago
Generalization. Would be interesting discussion with details. Pop is growing. What's your concern - global warming, fertility rates, pollution, nuclear arsenal, running out of resources? Doesn't seem like we are doing that badly and that pop can't drop if get below renewable resource level or adjust to new ways of making energy/food, etc. Does seem likely that on an extremely long time scale, we need to get multi-planetary, which is "realistic" if we give a reasonable time frame of, say, 10,000 years. As far as the sun dying, that's beyond even parent point's timeline. This is very things start to get questionable if we never get to even .1 of c (e.g. Project Orion "realistic" estimates). Alpha Centauri is relative close at 4.something ly, but other "potentially habitable/useful" star systems are way out there.
- sha256kira 5y ago
  Agreed. The great filter and collapse theory in general are fascinating in theory and can motivate some great positive action but they can't undermine the fact that humans beings are doing better than they've ever done in our history by almost every imaginable metric.
  - amanaplanacanal 5y ago
    Plus humans are extremely adaptable. Even before we invented agriculture, people had colonized the whole planet, except for Antarctica. It would be hard to kill us all off.
    - not_jd_salinger 5y ago
      > humans are extremely adaptable This is a strange claim I see repeated over and over, but it has very little evidence to justify it. The only piece of evidence people present is: > people had colonized the whole planet, except for Antarctica This is true of a fairly large number of organisms on Earth. On top of this humans have only been around for ~200,000 years, that's not long at all. Humans have not survived a single mass extinction event. So far we've seen humans travel around a planet that has been relatively stable for that period of time. There have been plenty of species that have traveled around with us that didn't even need to rely on extra tools, clothing or the use of energy to survive. Humans share several vulnerabilities with other megafauna that have all gone extinct. A major one is a fairly long gestation, plus small number of offspring per generation. Human young likewise need tremendous amounts of care and energy to raise to mature adulthood. Additionally human have fairly high energy requirements to support their complex brains. We've seen exponential rise in human population only because humans have had access to excessive amount of non-renewable, high-energy density sources of energy. It just happens that humans have lived on a planet that has mostly been within survivable temperature changes, with historic climate changes happening on time scales that lead to easy migration. As you pointed out, the one continent that does not have an environment that supports human life remains empty. Humans can't survive a wet bulb temperature of 35C. Until just recently we never saw that temperature on this planet. As we see more and more places reach that temperature more often, I suspect we'll see how frail human adaptability is.
      - edgyquant 5y ago
        > his is true of a fairly large number of organisms on Earth Is it though? How many other large, multicellular, organisms live on every continent without humans having brought them there?
        zabzonk 5y ago
        Seals. Birds.
        5y ago
  - not_jd_salinger 5y ago
    > the fact that humans beings are doing better than they've ever done in our history by almost every imaginable metric. That's because we have had ready access to insanely abundant high-energy density source of energy. The non-fossil fuel supported carrying capacity of the planet for humans is estimated to be somewhere around 1 billion people. When the fuel runs out (if we don't cook ourselves first), that will collapse. It is nothing intrinsic about humans that have lead to our recent success, just access to lots of nearly free energy. edit: why the downvotes? Is there even anything controversial in these statements? HN's fear of bad news is getting out of hand.
    - myrmidon 5y ago
      What is your source for the 1 billion estimate? Because that seems completely, non-credibly *low* to me. I also strongly believe that we could cover all our energy needs with renewable sources within a few decades if we really wanted to (even assuming no significant advances in tech), and this seems mostly non-disputed to me (because that is literally what nation-states are currently planning/doing). > Is there even anything controversial in these statements? Yes. Your statements seem not credible to me and you cite no sources.
      - not_jd_salinger 5y ago
        1 billion is a rough estimate based populations prior to the massive boom in the industrial revolution that saw massive changes in the way agriculture is done. It could easily be 2 billion or so, but definitely not 7.8 billion. You can see the population history here[0.] To see the powerful impact of fossil fuels on carrying capacity you'll notice there's an important inflection point around 1920-1930. This is because of the advent of the Haber process[1] which allows us to use fossil fuels to create nitrogen based fertilizers. Lest you doubt the impact of the Haber process just look at trends in corn yield per acre since then [2]. It's truly remarkable. Additional gains there are from other industrialized, fossil fuel driven agricultural process. The Haber process requires hydrocarbons. In the wikipedia article you can see that it consumes 3-5% of the worlds natural gas production and 1-2% of the global energy supply. We have completely disrupted the natural nitrogen cycle [4] and so would be unable to produce anywhere near as much food without fossil fuels. Because we have disrupted this cycle it's not even obvious that we could go back to a world of pre-fossil fuel agriculture. So those are just some bit of information about my claims but let's take a look at yours: > we could cover all our energy needs with renewable sources within a few decades if we really wanted to... this seems mostly non-disputed to me This is wildly disputed, and I don't know anyone who credibly believes this without invoking "magic" future technology. For starters we haven't replaced fossil fuels with "renewables" at all so far. We've just used them to supplement our energy needs. You can see here [4] that global fossil fuel consumption has continued to rise. Then it is important to separate electricity from the more general subject of energy. Currently only 20% of global energy usage is electricity generation [5]. So even if you replaced the entire grid with renewables over night you would still be missing the vast majority of energy demands. We currently have no viable pathway for renewable energy in transportation. Alice Friedman has more notes on this than I could ever fit in a comment [6]. Transportation inherently requires high energy density fuels, and outside of passenger vehicles, battery technology does not have the density required for industrial shipping. It worth looking at our national energy flows to get a good sense of just how little of the energy we use comes from renewables [7]. But even if we look just at the electrical grid, in the US, we have some very obvious problems with "all" our needs. As you probably know, wind and solar are intermittent power sources that requires fossil fuel powered "peaker" plants to provide energy in down times. This had two problems. One you need energy storage technology that we do not currently have (you cannot use grid scale lithium batters, pumped hydro has geological constraints, molten salts only work with concentrated solar, compressed air requires decommissioned oil field, etc). The other problem is that even if you had perfect storage you need to now more than double the total energy production so you can fill those batteries. The should be enough sources for you to get started, but I have feeling I'll still get down votes and "hand wavy" explanations of how it will all work out. 0. https://en.wikipedia.org/wiki/World_population#/media/File:World_population_v3.svg https://en.wikipedia.org/wiki/World_population#/media/File:W... 1. https://en.wikipedia.org/wiki/Haber_process https://en.wikipedia.org/wiki/Haber_process 2. https://www.agry.purdue.edu/ext/corn/news/timeless/YieldTrends.html https://www.agry.purdue.edu/ext/corn/news/timeless/YieldTren... 3. https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_cycle https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_c... 4. https://ourworldindata.org/grapher/global-energy-substitution?country=%7EOWID_WRL https://ourworldindata.org/grapher/global-energy-substitutio... 5. https://www.iea.org/reports/world-energy-outlook-2019/electricity https://www.iea.org/reports/world-energy-outlook-2019/electr... 6. https://www.resilience.org/resilience-author/alice-friedemann/ https://www.resilience.org/resilience-author/alice-friedeman... 7. https://flowcharts.llnl.gov/content/assets/images/charts/Energy/Energy_2020_United-States.png https://flowcharts.llnl.gov/content/assets/images/charts/Ene...
  - hashkb 5y ago
    Cooperation is the key metric I'm considering. It's becoming more critical that we learn to, and we are not even trying.
beervirus 5y ago
On a long enough time line, the survival rate for everyone drops to zero.
- arthurcolle 5y ago
  I am Jack's existential dread
delecti 5y ago
Sure eventually, but there's no clear indication if that's 10 years away, 10 billion years away, or a mere technicality as our descendants evolve into something that counts as a separate species.
- not_jd_salinger 5y ago
  We're currently undergoing the largest mass extinction event that will easily rank in the top 6 of life on this planet and could possibly compete with the end-permian. What makes you think we could possibly survive? Because we're the cause? Plenty of species in the past that have caused extinction events also perished. It seems far more questionable to assume we won't risk extinction in the geological near term. The parent is downvoted more out of existential fear rather than an honest assessment of the situation.
  - delecti 5y ago
    I think the parent comment was downvoted because it's not really contributing anything besides pessimism. As for us, I don't doubt the likelihood of a serious mass extinction, including possibly a severe drop in human population, but I can't see it being so severe as to cause an existential threat to us. No other species on this planet has had the ability to change the environment to suit it, or the ease of mobility to move where they can survive. Short of earth being entirely incompatible with complex life on the surface, I don't see humanity disappearing because of climate change.
    - hashkb 5y ago
      We need the pessimism. Irrational exuberance clearly doesn't work.
      - delecti 5y ago
        I have never seen anything remotely resembling exuberance around climate change. Everything I've seen is either pessimism or denial.

chadwittman 5y ago

Read more about the Great Filter, it's probable it's ahead of us.

riffraff 5y ago
is it _probable_? AFA we know we've been insanely lucky up to this point (as earthling life we went past multiple mass extinctions, we got multi-cellular life, multiple brains iterations, a society which still didn't wipe itself out etc) What makes it more likely for the filter to be ahead of us rather than behind us?
- caeril 5y ago
  Modern civilization is extremely dependent on fossil fuels. We've already passed peak conventional oil production, and we're now surviving on EXTRAORDINARY technical means of enhanced oil recovery. If we can't make the complete transition to renewables in the next thirty years, it's game over for a VERY long time. Future civilizations won't enjoy the benefit of Spindletop. Cheap energy sources won't be available near the surface of the crust for another > 50 million years. We won't go extinct, but it will be the 18th century for a very long time and nobody will leave this rock during that time. The Great Filter is right here, in front of us, in our lifetimes.
  - pdonis 5y ago
    > Cheap energy sources won't be available near the surface of the crust for another > 50 million years. Wrong. We already have one: nuclear energy.
    - caeril 5y ago
      That's a good point. It's pretty easy to construct and maintain fission reactors without fossil fuels. I bet enriching uranium was a snap in the 18th century, too. It will be even easier even getting to the enrichment phase in the future, with accessible ores about 30% as rich as they were when the nuclear age began. Looking forward to the fleet of electric concrete trucks carrying electrically-manufactured concrete loaded with batteries that were produced with lithium carbonate dug out of the ground by electric excavation rigs. All of this construction work will also not be disrupted by any social unrest resulting from 3 billion people starving to death because the Haber process no longer has enough cheap feedstock to sustain modern agricultural processes. Thanks for educating me.

Moodles 5y ago

Carl Sagan thought this, though he lived during the cold war so it's not surprising he did.

hnbad 5y ago
Considering where climate change is heading, it's surprising anyone doesn't think this.
- Taylor_OD 5y ago
  I agree in our case but this wouldnt be universal. Life may thrive in very hot planets if their evolutionary track was different.
- scarmig 5y ago
  Climate change is very real and worth addressing, but it's extremely unlikely to wipe out human civilization. It's just going to be costly and kill millions, not billions.
  - ses1984 5y ago
    Climate change by itself could be extremely unlikely to wipe out human civilization but it could be the catalyst that sets other events in motion like nuclear war.
  - darthrupert 5y ago
    Climate change doesn't have to directly kill us all. It could be the trigger to something else that does.
  - miltondts 5y ago
    Extremely unlikely to wipe out all humans. I agree. Current civilization, I'm not so sure. For the reasoning: https://www.youtube.com/watch?v=IESYMFtLIis https://www.youtube.com/watch?v=IESYMFtLIis
  - hnbad 5y ago
    Can you clarify what you mean by "millions"? The Syrian civil war is estimated to have killed just short of half a million people. The pandemic easily has a global death toll of roughly 4 million people so far. The Chalisa famine of 1783/1784 is estimated to have killed 11 million people. The Spanish flu killed at least 17 million people, though some of the more dramatizing estimates place it closer to 100 million. According to some researchers, climate change is already killing 100,000 a year[1]. So I assume you're not thinking of just seven or eight digits unless you're exceedingly optimistic. Climate change will make parts of the world inhabitable that are currently populated by humans. It will also result in crop failures, which will cause famines. In some cases formerly native crops will no longer be supported by the changing local climate or farmland may become completely unusable. Potable water will become harder to source. Water contamination is a source of many deadly diseases. Even if we assume most of the deaths will be concentrated in places like Africa or the Indian subcontinent, the global economy relies on these places for resources and cheap labor. People in ongoing climate catastrophes also don't tend to stay put and die in an orderly fashion, they become refugees or riot against their governments. Things can get politically messy even in the nations next door as humans tend to be uncomfortable with political chaos and mass deaths. But unlike the Spanish flu, or the potato famine, or COVID, climate change is not a temporary blip that happens and then goes away. If all the carriers of the plague have died, nobody dies from the plague unless they get infected handling the dead. Famines can starve millions to death but once there's another harvest the survivors have food again. Climate change isn't like that. If climate change creates a drought, that's not just a drought, that's now dry season and it will be dry season every year from now. There are currently 7.8 billion humans. There's absolutely no reason to believe climate change can't kill billions, especially once it's managed to kill the first hundreds of millions. Keep in mind that it's not about "addressing" climate change. It's not a moldy bathroom tile that you need to clean up or replace before the mold spreads everywhere. It's a fire our entire way of life is fueling every single day. We know what needs to be done to slow it down to survivable levels (or at least levels that are lethal for less than 1% of us) but we can't just pass legislation or appeal to personal responsibility to do that because it involves changes that would be economical suicide for anyone doing it alone. The world economy is playing a game of chicken with each other and nobody is bluffing. [1]: https://grist.org/climate/how-many-people-has-climate-change-killed-already/ https://grist.org/climate/how-many-people-has-climate-change...

bob33212 5y ago

Civilizations are only detectable for a short period of time. Once they understand physics, they no longer need radio waves or Dyson spheres or to travel through what we call spacetime.

yreg 5y ago
Why wouldn't they need megastructures and travel once they understood enough physics?
- bob33212 5y ago
  Space and time may be emergent, we don't know, all we do know is that our current model of physics is missing something. Quantum Gravity for example and We don't know what happens inside a black hole either.
  - yreg 5y ago
    That’s a non-answer though. Do you mean they are guaranteed to discover another “realm” and move to it? Why? It might not be possible, no matter how much physics one knows. Or do you take the Fermi paradox itself as a proof of the solution?
    - bob33212 5y ago
      Yes, it seems that the Fermi paradox implies that other civs progress beyond what we consider signs of intelligent life. The great filter seems less likely as we get close to colonizing other planets, and then other solar systems.
      - AnimalMuppet 5y ago
        I question your use of "implies" there. It implies no such thing. What you suggest is one possible answer, nothing more.
        5y ago

aetherson 5y ago

Short lived on those timescales, yes. But not necessarily short lived in terms of our perspective. If we imagine that in the last 5 billion years, there have been a good solid 10,000 post-industrial civilizations, and each of those civilizations has lasted 10,000 years (in the post-industrial stage where they're detectable), then that implies that of the last 5,000,000,000 years, 100,000,000 of them have been host to a post-industrial civilization: a given year has on average 0.02 currently present civilizations in it. Now, this hypothesis does probably imply that significantly interstellar civilizations are impossible, since it seems like if you've colonized say 20 stars, what disaster could possibly end your civilization? (I think the most likely scenario is that we're the only civilization ever to have developed in the Milky Way. Everything else seems like it assumes a lot of additional stuff.)

miltondts 5y ago
> if you've colonized say 20 stars, what disaster could possibly end your civilization? Unfortunately, war with another civilization.
- aetherson 5y ago
  I mean, maybe. Honestly hard for me to imagine war actually going on between two interstellar civilizations. But even if it did, it seems like in 99% of all cases, that would leave at least one of the two civilizations still around. We're looking for explanations, in this hypothesis, that leave 98% of all time with no civilizations.
  - kadoban 5y ago
    Maybe war between two spacefaring civilizations is too "easy". eg something like: throwing asteroids at ~the speed of light is necessarily a cheap thing to do once you're at that level, and everyone just dies. Like if on Earth nukes were something everyone could cook up in their backyard in an afternoon, we'd all be gone pretty quick. Not sure that really makes any sense though.
    - 5y ago