It seems extremely unlikely that we’ll have Venusian style runaway global warming anytime in the next few thousand years assuming no major geoengineering occurs. A major part of why that happened on Venus is due to the lack of plate tectonics on Venus. Without that, there are serious limits. Earth could become much more inhospitable to humans but it would be very difficult to even have more than a 20 or 30 degree Farenheit increase. So humans would have to live near the poles, but it wouldn’t be fatal.
A more serious long-term obstruction to going to the stars is that it isn’t completely clear after a large-scale societal collapse that we will have the resources necessary to bootstrap back up to even current tech levels. Nick Bostrom has discussed this. Essentially, many of the resources we take for granted as necessary for developing a civilization (oil, coal, certain specific ores) have been consumed by civilization. We’re already exhausting the easy to reach oil and have exhausted much of the easy to reach coal (we just don’t notice it as much with coal because there’s so much). A collapse back to bronze age tech, or even late Roman tech might not have enough easy energy sources to boot back up. That will be especially likely if the knowledge of how to make more advanced energy sources becomes lost. I suspect that there are enough natural resources now still left that a collapse would not prevent a future rise again. But as we consume more resources that becomes less true. And even if we develop cheap alternatives like fusion power, if we’ve already exhausted the low-tech resources we’re going to be in very bad shape for a collapse. Indeed, arguably a strong reason for conserving energy now is to keep those resources around if things go drastically bad.
The big question for these issues is how much ‘slack’ we had over our development trajectory. A new civilization could cultivate biomass for energy, and hydropower provides a fair amount of electricity without steady use of consumables. I’d say probably but not very confidently we could recover after intense resource depletion and collapse.
Right, and in some respects we’d actually have tiny advantages the second time around, in that a lot of metals which are hard to separate from ores are already separated so humans who know where to look will have easy sources of metal. This will be particularly relevant for copper and aluminum which are difficult to extract without large technological bases.
Yes, and let’s keep in mind that no civilization with colonial-era tech has ever collapsed to a pre-industrial level, and it isn’t at all clear that such an event is possible. You’d have to kill more than 99% of the population and keep the survivors from forming town-sized communities for a couple of generations, and even then the knowledge is still available in books. To me this just looks like reasoning from fictional evidence—there are lots of stories about primitive survivors of lost civilizations, so people assume that must be a plausible outcome.
That may be using a bad reference class. We know that slides backwards have happened for other tech levels. I don’t see an intrinsic reason to think it couldn’t happen for a society at or near our tech level.
When low-tech societies collapse, the reason is typically that they lose access to some resource that’s essential to their way of life, and they can’t adapt because their technology base doesn’t include anything they can switch to as a substitute. Since the number of potential substitutes for any given resource grows steadily as technology advances we would expect more advanced societies to be more resistant to that type of problem, and indeed that’s what we see in the historical record. If you can’t keep the nuclear power plants working you can always fall back on oil, or natural gas, or coal, or hydro, or windmills, and so on all the way down the chain to bronze age power sources. Then, once you find a level you can sustain in your new situation, you can start rebuilding transportation and industry to get back to where you were before the disaster.
Which is why I say that the “big disaster causes civilization to collapse” scenario is fictional evidence. AKAIK it has never happened to any society that had even colonial-era tech, and there are good reasons to think it can’t unless you posit such a high casualty rate (>99%) that instant extinction becomes an equally plausible outcome.
It seems extremely unlikely that we’ll have Venusian style runaway global warming anytime in the next few thousand years assuming no major geoengineering occurs. A major part of why that happened on Venus is due to the lack of plate tectonics on Venus. Without that, there are serious limits. Earth could become much more inhospitable to humans but it would be very difficult to even have more than a 20 or 30 degree Farenheit increase. So humans would have to live near the poles, but it wouldn’t be fatal.
A more serious long-term obstruction to going to the stars is that it isn’t completely clear after a large-scale societal collapse that we will have the resources necessary to bootstrap back up to even current tech levels. Nick Bostrom has discussed this. Essentially, many of the resources we take for granted as necessary for developing a civilization (oil, coal, certain specific ores) have been consumed by civilization. We’re already exhausting the easy to reach oil and have exhausted much of the easy to reach coal (we just don’t notice it as much with coal because there’s so much). A collapse back to bronze age tech, or even late Roman tech might not have enough easy energy sources to boot back up. That will be especially likely if the knowledge of how to make more advanced energy sources becomes lost. I suspect that there are enough natural resources now still left that a collapse would not prevent a future rise again. But as we consume more resources that becomes less true. And even if we develop cheap alternatives like fusion power, if we’ve already exhausted the low-tech resources we’re going to be in very bad shape for a collapse. Indeed, arguably a strong reason for conserving energy now is to keep those resources around if things go drastically bad.
The big question for these issues is how much ‘slack’ we had over our development trajectory. A new civilization could cultivate biomass for energy, and hydropower provides a fair amount of electricity without steady use of consumables. I’d say probably but not very confidently we could recover after intense resource depletion and collapse.
Right, and in some respects we’d actually have tiny advantages the second time around, in that a lot of metals which are hard to separate from ores are already separated so humans who know where to look will have easy sources of metal. This will be particularly relevant for copper and aluminum which are difficult to extract without large technological bases.
Yes, and let’s keep in mind that no civilization with colonial-era tech has ever collapsed to a pre-industrial level, and it isn’t at all clear that such an event is possible. You’d have to kill more than 99% of the population and keep the survivors from forming town-sized communities for a couple of generations, and even then the knowledge is still available in books. To me this just looks like reasoning from fictional evidence—there are lots of stories about primitive survivors of lost civilizations, so people assume that must be a plausible outcome.
That may be using a bad reference class. We know that slides backwards have happened for other tech levels. I don’t see an intrinsic reason to think it couldn’t happen for a society at or near our tech level.
When low-tech societies collapse, the reason is typically that they lose access to some resource that’s essential to their way of life, and they can’t adapt because their technology base doesn’t include anything they can switch to as a substitute. Since the number of potential substitutes for any given resource grows steadily as technology advances we would expect more advanced societies to be more resistant to that type of problem, and indeed that’s what we see in the historical record. If you can’t keep the nuclear power plants working you can always fall back on oil, or natural gas, or coal, or hydro, or windmills, and so on all the way down the chain to bronze age power sources. Then, once you find a level you can sustain in your new situation, you can start rebuilding transportation and industry to get back to where you were before the disaster.
Which is why I say that the “big disaster causes civilization to collapse” scenario is fictional evidence. AKAIK it has never happened to any society that had even colonial-era tech, and there are good reasons to think it can’t unless you posit such a high casualty rate (>99%) that instant extinction becomes an equally plausible outcome.