Stephen Hawking: Off Earth by 2110?

[Pelranius]

Second, unless something major happens (i.e, Dino killer asteroid), I don't think humanity will go out completely with a bang. More likely we'll collapse back to a preindustrial age and be effectively stuck there.

I doubt that we'll be eternally stuck in a preindustrial age after a global collapse. What worries me is that an industrial collapse will kill most of the world's population (6 out of 7 might be very optimistic). Sure, the survivors can probably eventually build interplanetary and interstellar colonies, but what about the 6 billion poor saps who became kaput?

[Temujin]

Well, my rationale is based on the idea that if we lose enough knowledge and technology to put us back in a preindustrial age, there likely won't be enough cheap and easy to acquire resources to allow for industrial revolution 2.0. If we keep enough knowledge and functional technology, even if its only in a few countries, than we can try to work around that limitation by using alternatives.

[GrandMasterTerwynn]

Second, unless something major happens (i.e, Dino killer asteroid), I don't think humanity will go out completely with a bang. More likely we'll collapse back to a preindustrial age and be effectively stuck there.

I doubt that we'll be eternally stuck in a preindustrial age after a global collapse. What worries me is that an industrial collapse will kill most of the world's population (6 out of 7 might be very optimistic). Sure, the survivors can probably eventually build interplanetary and interstellar colonies, but what about the 6 billion poor saps who became kaput?

No. Once technological civilization goes, that's it. We used up all the easily-extractable, highly-concentrated energy sources that we used to kick-start our own industrial revolution. All the surface mine-able coal was tapped out years ago. Coal now comes from deep shafts, or mountaintop removal. The only light, sweet crude oil left in the world is in deep reservoirs requiring complicated drilling technology to reach. The same goes for natural gas. Anything more esoteric requires a mass of working high industry to bootstrap off of. If civilization collapses, we're restricted to doing work by burning biomass (either by directly setting it on fire, or feeding it to slaves and beasts of burden.)

If technological civilization falls apart, the energy sources available to its' descendants would be enough to sustain (at best) 16th or 17th century lifestyle with the occasional bursts of 18th or 19th century activity as forests wax and wane and civilizations stockpile the charcoal needed to fire large-scale steel production/recycling.

[Junghalli]

If technological civilization falls apart, the energy sources available to its' descendants would be enough to sustain (at best) 16th or 17th century lifestyle with the occasional bursts of 18th or 19th century activity as forests wax and wane and civilizations stockpile the charcoal needed to fire large-scale steel production/recycling.

Theoretically, could a farsighted and dedicated government get back to the point of being able to invent nuclear power and spacecraft by stockpiling resources and carefully rationing them to the bare minimum necessary to sustain a high technology base?

I know it isn't plausible with real humans, but if we postulate a population of sufficiently altruistic and farsighted transhumans or whatever could it theoretically be done?

[Sarevok]

What about hydro-power and wind power ? A Earth with far less humans than today could try to jump to 20th century tech level using these two.

[Darth Yan]

apparently a big asteroid like the one in armageddon will be here in 2037. That will kill us.

[PaperJack]

apparently a big asteroid like the one in armageddon will be here in 2037. That will kill us.

you forgot about the 1-in-6,250 chance of it actually hitting the planet (99.98% probability of missing)

[Darth Yan]

what would be needed to rebuild the space program or save ourselves from doom?

[Sea Skimmer]

No. Once technological civilization goes, that's it. We used up all the easily-extractable, highly-concentrated energy sources that we used to kick-start our own industrial revolution. All the surface mine-able coal was tapped out years ago.

Why on earth do you believe that the Industrial Revolution was fueled by surfaced mined coal? It most certainly was not. That's why coal miners back then usually died before age 20, they worked underground which was absurdly dangerous. Coal was being mined underground before the Romans using simple bell pits. In fact surface mining was never a very credible source of coal except with modern heavy machinery to strip away overburden. You could find coal seams on the surface sure, but they'd quickly be followed underground.

Anyway, resource demands would be so vastly reduced, and the ruins of modern cities could be looted for such colossal amounts of scrap metal that shortages are unlikely. Think about how much scrap metal is in the rebar of one big concrete building, it can be tens of thousands of tons. You can knock that building down by hand and recover it all, China actually does this as we speak since they have cheep enough labor to make it worthwhile. We'd also have a huge advantage from so many rights of of way, tunnels and cuttings existing already. Even if the roads and railroads are decayed to nothing, simply having the path cut is a big advantage they didn't have in the 18th century. If humanity can survive it can rebuild. But survival sure isn’t a given.

[Temujin]

Anyway, resource demands would be so vastly reduced, and the ruins of modern cities could be looted for such colossal amounts of scrap metal that shortages are unlikely. Think about how much scrap metal is in the rebar of one big concrete building, it can be tens of thousands of tons. You can knock that building down by hand and recover it all, China actually does this as we speak since they have cheep enough labor to make it worthwhile. We'd also have a huge advantage from so many rights of of way, tunnels and cuttings existing already. Even if the roads and railroads are decayed to nothing, simply having the path cut is a big advantage they didn't have in the 18th century. If humanity can survive it can rebuild. But survival sure isn’t a given.

This is one thing I've considered; of course the amount recoverable and how much we could benefit would depend upon how far technologically we fell and how long it took us to get our shit together before pillaging these ruins in earnest. In a case where pockets of modern civilization survived, those relatively empty cities would be a smorgasbord of resources.

[GrandMasterTerwynn]

If technological civilization falls apart, the energy sources available to its' descendants would be enough to sustain (at best) 16th or 17th century lifestyle with the occasional bursts of 18th or 19th century activity as forests wax and wane and civilizations stockpile the charcoal needed to fire large-scale steel production/recycling.

Theoretically, could a farsighted and dedicated government get back to the point of being able to invent nuclear power and spacecraft by stockpiling resources and carefully rationing them to the bare minimum necessary to sustain a high technology base?

I know it isn't plausible with real humans, but if we postulate a population of sufficiently altruistic and farsighted transhumans or whatever could it theoretically be done?

Very far sighted. You'd need to be able to assemble enough high-strength steel to build, say, a collection of cellulosic ethanol plants. While you're shooting for the moon throw in some thermal depolymerization plants to synthesize industrial hydrocarbons. These will enable you to mine and refine uranium ore. You'd have to collect together and hoard metals already processed by the prior technological civilizations. All while ensuring you preserve the knowledge needed to build all that stuff.

At which point, these folks would have to fight off their more nearsighted neighbors.

What about hydro-power and wind power ? A Earth with far less humans than today could try to jump to 20th century tech level using these two.

Both of these are location-dependent. And humans could exploit wind and water power from as long as there have been windmills and watermills. The problem becomes "well, what if I want to build something fancier than a watermill?" Which leads you back to needing an industrial and technological base first.

Of course, you could get a big leg up on your neighbors if, during the last dying gasps of technological civilization, you seize control of a preexisting hydro-electric plant. And protect your hold over it from your neighbors who have come to the same conclusion. And keep your fight over the plant from inadvertently blasting it into the hereafter.

Why on earth do you believe that the Industrial Revolution was fueled by surfaced mined coal? It most certainly was not. That's why coal miners back then usually died before age 20, they worked underground which was absurdly dangerous. Coal was being mined underground before the Romans using simple bell pits. In fact surface mining was never a very credible source of coal except with modern heavy machinery to strip away overburden. You could find coal seams on the surface sure, but they'd quickly be followed underground.

Conceded. In the optimistic case, one would hope that there will still be coal that can be accessed by the sort of timber-supported deep shaft mines someone from the 17th or 18th century could build. The not-so-optimistic case asserts this doesn't matter because the previous technological civilizations have tapped out coal once they finished exhausting the oil.

Anyway, resource demands would be so vastly reduced, and the ruins of modern cities could be looted for such colossal amounts of scrap metal that shortages are unlikely. Think about how much scrap metal is in the rebar of one big concrete building, it can be tens of thousands of tons.

Indeed. Our descendants could satisfy their need for steel to make swords (and/or locomotives) with by mining the ruins of our cities. But, how useful this will be will depend on how far civilization falls, and how nasty the time afterward is. As long as the fall isn't too hard and too nasty, those in-the-know will have a tremendous leg up. Otherwise, they're going to have to sort out the good steel from the rust, and they'll just melt it down for shiny swords and armor anyway.

[Sea Skimmer]

This is one thing I've considered; of course the amount recoverable and how much we could benefit would depend upon how far technologically we fell and how long it took us to get our shit together before pillaging these ruins in earnest. In a case where pockets of modern civilization survived, those relatively empty cities would be a smorgasbord of resources.

Anyone who can smelt iron can exploit a city, and even people who can't do that could still find many items they can use. While many larger items would be hard to exploit without somewhat modern cutting tools anyone can start tearing apart cars and pulling up guardrails. Something like a heat treated hammer head could survive a couple hundred years in usable condition if it wasn’t constantly wet, and would be valuable salvage. Being able to recover simple items like this would really help short circuit the rebuilding process.

[Pelranius]

Theoretically, could a farsighted and dedicated government get back to the point of being able to invent nuclear power and spacecraft by stockpiling resources and carefully rationing them to the bare minimum necessary to sustain a high technology base?

I know it isn't plausible with real humans, but if we postulate a population of sufficiently altruistic and farsighted transhumans or whatever could it theoretically be done?

The Soviet seemed to have done something like that. Governments big on central planning (I use that term relatively) like China have stockpiles of critical parts and materials stashed away, and will probably possess the means to depend them, but that's only if they can prioritize the building of such equipment, which would be complicated by how many survivors you have left (which ironically I think would be more problematic if there are more survivors, that means you have to devote more resources to immediate necessities than to spaceflight and nukes).

[Sarevok]

Just how many megawatts of electrical power do you need for a self sustaining mid 20th century civilization ? Hydro and wind sucks because the world demand far outstrips what could be easily tapped. Now there are countries like Sri Lanka where 31 percent of power comes from hydro. And Sri Lanka is an island with no big rivers. Instead they have tons of smaller rivers and numerous small hydropower projects. You do not require huge river engineering projects always to obtain hydropower. The output from many small plants is not sufficient for a huge first world country. But what if it could sustain a small nation with enough tech to build cars and airplanes ?

[aerius]

The city of Toronto by itself sucks up something like 4-5GW and it's hardly self sustaining. To produce all the resources & technology required to sustain itself you'd have to add in Hamilton, the Sudbury area, Oshawa, a bunch of farmland, and a bunch of fossil fuels. Then to supply all the people, infrastructure, and secondary support systems you're basically looking at all of Ontario and Alberta put together. By the time you do that you're looking at close to 40GW of power generation. That gives you cars, trains, and eventually airplanes after the mothballed factories & support industries are reopened.

With regards to Sri Lanka, their hydropower consumption peaked at about 4.5 billion kWh/year. To put that in perspective, a single nuke station in Ontario puts out roughly 7 times as much power. We have 3 nuke plants, plus fossil fuel, plus hydro. A single nuke plant by itself puts out around 3 times as much electricity as Sri Lanka consumes in a year, total.

[Molyneux]

I'd just like to thank all the people in this thread for giving me nightmares. It's easy to avoid realizing just how screwed we really may be, thanks to a few bad decisions made by our parents and grandparents' generation.

[Temujin]

I'd just like to thank all the people in this thread for giving me nightmares. It's easy to avoid realizing just how screwed we really may be, thanks to a few bad decisions made by our parents and grandparents' generation.

Your welcome!

Unfortunately human nature is selfish and prone to short term thinking. What we need is something that isn't seemingly nebulous and uncertain, like how climate change and resource depletion seems to most people, and more direct and immediate to light a fire under our collective asses.

[GrandMasterTerwynn]

Just how many megawatts of electrical power do you need for a self sustaining mid 20th century civilization ? Hydro and wind sucks because the world demand far outstrips what could be easily tapped. Now there are countries like Sri Lanka where 31 percent of power comes from hydro.

And I hear Sri Lanka is known for its heavy industry . . .

And Sri Lanka is an island with no big rivers. Instead they have tons of smaller rivers and numerous small hydropower projects. You do not require huge river engineering projects always to obtain hydropower. The output from many small plants is not sufficient for a huge first world country. But what if it could sustain a small nation with enough tech to build cars and airplanes ?

To run an automobile factory requires enough power to supply a town of 25,000 inhabitants. This doesn't include the factories required to build the parts that will be assembled into a car. It doesn't include the rubber plant required to make the tires. It doesn't include the steel mill required to make the iron and steel that gets transformed into car frames, car parts, and drivetrains. It certainly doesn't include the huge infrastructure investment needed to build and maintain the network of roads these cars would run on. This neglects the energy needs of the people who work at these factories. It's nice to say that these people will get by living in crowded, powerless, hovels . . . except that you'll have mass uprisings if you actually tried that. Highly industrialized mid-20th century civilization requires a lot of power generation. You may be able to assemble a car using a single factory, but that factory has a bunch of factories feeding into it, and these factories have mills and other factories feeding into them; and all of those require lots of energy to burn and metals to loot from the ruins of our cities.

You'd be better off aiming a little lower. Eighteenth or nineteenth century. You don't need cars and airplanes when you could get far more transportation bang for your buck by building a network of railroads and making every other road suitable for lighter traffic, like foot or oxcart traffic. You can pack people into compact, fairly dense, housing; since you'll have the advantage of germ theory and sanitation. This would leave ample room for traditional "organic" farming. The people might not be exceedingly happy with their living conditions, but at least the economic disparity can be minimized without the huge costs of trying it with a 20th century lifestyle.

[Junghalli]

It's nice to say that these people will get by living in crowded, powerless, hovels . . . except that you'll have mass uprisings if you actually tried that.

We probably would, but then we're used to a rich modern civilization and all its perks. Postapocalyptic people who have no personal memory of the conveniences of the modern world and only know about it from maybe stories told by their grandparents if that would probably have lower expectations, I think you could probably get them to be relatively content with a lower standard of living than we have now, especially if they have hope that things will be better for the next generation or the one after and their sacrifices will help make that possible.

As you yourself pointed out our modern knowledge of sanitation and disease, perhaps along with a certain amount of centralized planning (e.g. stockpiling food supplies to last hard years and discouraging excess reproduction to avoid famine-driven boom and bust population cycles) and maybe some "strategic" limitated applications of high tech (e.g. in medicine and food preservation) you might be able to have a relatively low-tech lifestyle without it being the horror show that premodern world was. If the big sacrifice is mainly conveniences (no quick travel, no TV, no light at night except candles etc.) and most people had never known anything better I don't think discontent would necessarily really be that massive.

[Broomstick]

As you yourself pointed out our modern knowledge of sanitation and disease, perhaps along with a certain amount of centralized planning (e.g. stockpiling food supplies to last hard years and discouraging excess reproduction to avoid famine-driven boom and bust population cycles) and maybe some "strategic" limitated applications of high tech (e.g. in medicine and food preservation) you might be able to have a relatively low-tech lifestyle without it being the horror show that premodern world was. If the big sacrifice is mainly conveniences (no quick travel, no TV, no light at night except candles etc.) and most people had never known anything better I don't think discontent would necessarily really be that massive.

Pardon me - I'm going to ramble just a bit.

I think folks underestimate just how far 19th Century tech actually made it before we electrified everything. Actually, my mother grew up in St. Louis in the early 20th Century and, despite being in the middle of a major urban area, her family didn't have electric lights until she was around 10 years old. It's not that many generations back that we were "pre-modern". Even then, though, standards of living had increased significantly over the prior 50 years (my mother's mother's generation, if you will). Germ theory and sanitation had vastly improved health by simply convincing people to wash their hands and don't shit in your drinking water and the concept of sterilization was common knowledge. Vaccines for things such as smallpox, tetanus, and other maladies were already in common use. None of these things require electric power or high tech to produce.

Lighting might return to gas - but you can make burnable gas for that purpose out of household waste, and use it for cooking, too, as well as commercially produce it. I don't foresee a return to a heavy use of whale oil (not enough whales, for one thing) but you can use vegetables oils and fats for lighting and humanity did so for thousands of years (candles require wax - most of which is made from petroleum these days, in the old days the source was beeswax or bayberry and there wasn't really enough by the 19th Century, hence a heavy use of (non-petrol) oil and gas for lighting.). I do wonder, however, if we could have solar lighting with 19th Century tech levels? Becquerel was doing experiments in this area in the 1840's, wasn't he? Now that the theory and kinks have been worked out it might be possible for 19th Century tech levels to produce this. I don't know, it's an interesting question, isn't it?

Likewise, things such as radio and telegraph should be sustainable at 19th Century tech levels. Sound recordings, Photography. None of that need be lost even if we lose petroleum because they all pre-date petroleum as a major resource.

For food preservation freezing might be problematic without ample power in the form of electricity However, early experiments in refrigeration, including the production of artificially produced ice, started in the 1750's and by the 1870's commercial refrigeration was a reality - on a large scale, usually at breweries or icehouses, the latter of which would then distribute ice to retail customers, including households, for use in "iceboxes" year round.. This is also when refrigerated shipping arose in trains and ocean-going ships. So refrigeration is doable without petroleum, although the home would probably go back to ice boxes. All the other food preservation methods - salting, pickling, drying, smoking, and canning - would be very much in reach. All of those were developed and more or less perfected before the Age of Oil and Age of Electrification. On top of that, we know a LOT more about nutrition than people 150 years ago did and as a result would likely eat better. There might be some initial difficulty in re-creating older techniques for making sealable tin cans and jars suitable for canning but that is NOT an insurmountable obstacle.

Oh, about food - one thing that has happened since 1500 AD is the swapping of food all around the world. EVERYONE eats a much, much more diverse diet than ever before. Even if the world goes to hell tomorrow a hundred years from now people in Europe and Asia will most likely have such American crops as tomatoes, various peppers, beans, squash, pecans, and potatoes to eat. Meanwhile, the Americas will have such things as turnips, beets, eggplant, different various beans, wheat, barley, beef, pork, ostrich, and Og knows what else. One can hardly keep track of which foods originated where - I mean, kiwi fruit aren't native to New Zealand, and I'm not sure where bananas originally came form. The last 500 years will leave a legacy that won't be erased, even if the electric lights go out.

Oh, roads - it has already been mentioned, but even if our roads fall to ruin the right-of-ways cut through hills and mountains will remain (tunnels and bridges will eventually collapse, of course, and I suspect it will be easier to re-create bridges than some of the sophisticated tunnels like the England-France Chunnel). Re-building, or even just maintaining, those roads will be MUCH easier than building them in the first place (the very same reason some of the old Roman roads have survived into the modern day, either following the same routes or even in a few places still using stuff built by the Romans 2,000 years ago).

The world has been mapped, for heaven's sake! Longitude, latitude, magnetic drift... this has all been worked out already. We know where things are, and that knowledge won't entirely disappear. There would still be international shipping even if we had to return to the Age of Sail - just a heck of a lot slower.

A horseless carriage is doable without petroleum - it will just have to run on something else, whether that's alcohol (Ford's Model T could run on ethanol), some sort of oil, or back to steam power (and steam automobiles were relatively common at one point) which might work for trucks transporting goods from railroad depots. Railroads, of course, can run on steam, and that steam can be generated by anything burnable, from wood to coal to whatever.

Airplanes would be a bit trickier - the key is having an engine that is both powerful and relatively light weight. Well, that, and leaning how to build a lifting wing of sufficient size. Airplanes have run on various forms of diesel, on ethanol (Brazil uses a whole fleet of those for agriculture these days), and even on steam power (steam being generated by burning a type of oil). They don't pre-date gasoline, but they can be run on something other than petrol-derived fuel IF you have the tech to produce a suitable engine. Which was the case by, oh, around 1910-1915 (yes, there were earlier airplanes - as early as 1903 but they were far from practical and, in fact, when someone recreated the original 1903 Wright Flyer the FAA refused to certify it airworthy - because my modern standards it wasn't. It was a shitty airplane and notable because it was first, not because it flew well). Would that be reproducible with a technology crash? I don't know. Interesting to speculate. You can certainly build the structure of an airplane with 19th Century technology - hell, you just need some wood and cloth and paint and a little bit of sturdy cables and pulleys. People have had the material resources to build working gliders since... well... for the past several thousand years they only reason they didn't was they didn't know how to build a lifting wing. THAT was the huge breakthough - figuring out how to make an airfoil and knowing how big to make it. A bunch of POW's in Colditz prison built a workable glider out of wood scraps and discarded cloth under the noses of their Nazi guards (another "Tony Stark Award" if you ask me.. They Built It In An Attic! WITH A BOX OF SCRAPS!). This is NOT hard, the tricky part it that engine to keep it up in the air. Meanwhile - dirigibles are also doable with 19th Century tech, though likely you'd be limited to hydrogen for lifting power. In other hypothetical post-crash world trans-oceanic flight would probably be by dirigible/zepplin/blimp but it would still be faster than the old days of sailing across the Atlantic or Pacific.

I guess my point is that, although such a world would be very different, it would not necessarily be terrible or a life of deprivation. We could still have soap and water, decent sanitation, clean drinking water, vaccines, safe surgical procedures (I would hope anesthesia is remembered or rediscovered). Travel would still be possible, although probably slower than before and not quite so common or routine. We would still find out what's happening on the other side of the world, just not via satellite TV. We would still have recorded music, photographs of loved ones, and exotic things from all over (though almost certainly more expensive than before). There's a very good possibility we'd have some form of "horseless carriage", even if only for the upper classes, but probably also as cabs in urban areas. There would be lights at night, and in some locations they'd even be electrical. We'd have iceboxes to keep food cold. We'd have stoves. Urban areas might well have gas service piped into homes (they used to - and two of my apartments in Chicago still had the old gas pipes and fixtures, although they had been converted to electric by the time I moved in) for lighting and cooking. We'd still eat a far more diverse range of foods than our ancestors did. We might even have limited air travel, some solar power, and perhaps even things like desk calculators although they'd probably be bulkier than today's and pretty basic (circut boards can be made with a photoresist process doable by an amateur in the home - I know this, because my Other Half used to burn his own boards). We won't have routine air travel, artificial satellites (say goodbye not only to GPS navigation but also modern weather forecasting), or personal computers or the internet. We won't have new CGI movies from Hollywood (though likely we'd still have those already made). A lot of things will be gone but a comfortable lifestyle IS possible...

... once the dust settles and the inevitable billions of dead are buried. Because that sort of collapse would be horrific and bloody.

But, as I said, once the dust settles it is entirely possible for our descendants to achieve comfortable, healthy, and fulfilling lives. Here on Earth. Recycling the ruins of our 20th/21st Century glory days. I could probably be comfortable in a post-apocalyptic world of that sort... it the apocalypse part that scareS the shit out of me. The part where all the actual dying takes places.

[Junghalli]

Yeah, it sounds to me less like a technological civilization would be impossible without cheap fossil fuels and more like a technological civilization that looks just like ours would be impossible without them, at least until nuclear power was rediscovered. But why would an emerging technological civilization faced with a different set of challenges necessarily evolve in the same directions we did? If energy is much more expensive wouldn't it logically come to be reserved for areas where you get the most bang for your buck out of it (and, let's face it, also for benefiting the elites), instead of people trying to produce a clone of our civilization in an environment where it makes no sense to do so and failing to achieve any advancement as a result? And if they had records of our civilization that would probably help: they'd have goals to work towards and know which projects they should concentrate their resources on to eventually get back to something like the good old days. They would actually be able to realize "sure X doesn't really help us now but you need it to unlock Y which unlocks Z which unlocks nuclear reactors" in the manner that people often use sarcastically when talking about people who approach technological advance as if it was a game of Civilization.

But, as I said, once the dust settles it is entirely possible for our descendants to achieve comfortable, healthy, and fulfilling lives. Here on Earth. Recycling the ruins of our 20th/21st Century glory days. I could probably be comfortable in a post-apocalyptic world of that sort... it the apocalypse part that scareS the shit out of me. The part where all the actual dying takes places.

It sounds acceptable enough as a temporary state. Just as long as we aren't stuck that way forever; I'd hate to see humanity's potential permanently limited to some deeply suboptimal level (what Nick Bostrom calls a Crunch/Shriek scenario).

[Temujin]

It all depends on just what happens. If we get hit really hard and don't go extinct, we may end up with the survivors living little better than Neolithic age man. But even if we can't stop a decline, with some prep we could halt some of the slide and adapt some of the things Broomstick talks about, which strangely gives me a bit of Steampunk vibe. Then if we can preserve some even limited knowledge (or functioning examples) of nuclear, solar, etc. the remaining civilized parts of the world could perhaps rebuild sensibly, especially since the knowledge of what happened and why would not be lost to some mythologized past where we did something like piss off the gods or some shit.

[HMS Conqueror]

Since this debate seems to have moved to not if, but when and how mankind will imminently collapse, I wonder how many of you are survivalists? If I thought as many of you seem to I would be stockpiling guns, petrol and canned food right now, but do you put your money where your mouth is?

----------------------------

Ah, it was the opposite for me: when I was twelve I thought resource depletion &c. was a serious problem, but now I am at university I no longer do. There is in fact no clear link between resource consumption and economic growth. The invention of the silicon transistor, for instance, made computers better and cheaper and less consumptive of resources. The only potentially fundamental limit that exists is imposed by energy production, and that is far in excess of anything we will reach any time soon.

Really?

World GDP

World energy consumption

The two graphs clearly diverge. The GDP increased by 2/3 between 2000 and 2006, for instance, while the energy consumption went up only about 20%.

There's an interesting trend which shows up when one plays with the GDP/capita and energy consumption/capita charts on Google; mature 1st world nations such as Canada, Germany, and the US have stabilized their per capita energy consumption for the past 20-30 years, industrializing nations such as China and others in Asia have seen per capita energy use rise significantly, lastly, the poorest nations have been flatlined during this time period.

The GDP per capita charts show large gains in 1st world nations which indicates in efficiency, though I'd argue that a large portion of the gain was due to Enron style accounting and the abuse of financial instruments & credit. The industrializing nations are also seeing large GDP gains to go with their energy consumption, the gains in efficiency (if any, depending on the country) aren't enough to flatten out their per capita energy use. The poor countries are flatlined here as well, if not declining.

Put it together and we have a problem; most of the world's population lives in those rapidly industrializing nations, the ones with growing populations and rising per capita energy consumption. Efficiency is not going to save us until they're on a mature 1st world level. If they were to have the same energy consumption as a modern country like oh, Germany or France, it would require the construction of several thousand large nuclear generating stations over the next few decades.

We are many orders of magnitude away from any sort of energy limit - http://i27.tinypic.com/35jfip2.jpg

Even considering only the 'clean' sources doesn't change this much. It changes the price a little - but only a little. Nuclear is just a few % more expensive than fossil fuels right now, and cheaper if the AGW externality is accounted for.

And what is going to fuel this endless economic growth? Fairy dust and unicorn shit?

Capital accumulation and technological progression - just as in the past.

What capital accumulation? An overwhelming amount of the "capital" in existence today has around the same value as Monopoly money, with roughly the same real world purchasing power should the holder attempt to use it. A $10 billion CDO is not capital nor are non-agency MBSs, yet both are claimed as such by their holders.

Capital is physical productive things, not dollar bills. A semiconductor plant is capital, for instance. It beats making transistors by hand:

Petroleum arguable is a negative return on investment (in terms of energy) depending on which figures you believe. That isn't the point of it: petroleum is good because it's both energy dense and a liquid, so is convenient for use in vehicles. It's already not used in bulk electricity generation, because it's too expensive.

Only for oil shale, possibly for some types of tar sands and scavenging the last bits of oil out of depleted reservoirs. All other forms of oil production still have a positive EROEI, generally 5:1 or greater.

Yes, hence, "depending on what figures you believe": that oil shale and tar sands are still used, and more so as the price rises, despite their negative EROI. This is because EROI is not the important factor here: the great advantage of it is its convenience for use in vehicles. It's a storage device for energy first and foremost, being a source is just an added bonus, and not necessary for it to be useful.

[Temujin]

Since this debate seems to have moved to not if, but when and how mankind will imminently collapse, I wonder how many of you are survivalists? If I thought as many of you seem to I would be stockpiling guns, petrol and canned food right now, but do you put your money where your mouth is?

It's wise to be prepared for emergencies, but the massive stockpiling required for survivalist Armageddon costs a lot of money. If your reasonable well off it's a luxury you can afford, but a lot of us aren't that well off and are struggling just to keep our heads above water in a shitty economy. Besides, most survivalist nuts are no different than the wankers who talk about surviving a zombie apocalypse, i.e., they're not as good as they think they are and probably will be among the first to die.

[Broomstick]

Since this debate seems to have moved to not if, but when and how mankind will imminently collapse, I wonder how many of you are survivalists? If I thought as many of you seem to I would be stockpiling guns, petrol and canned food right now, but do you put your money where your mouth is?

Guns are fine, but ammo is what you really need to stockpile. Or better yet, the means to make ammo, because in a post-civilization world he who makes the bullets is arguably more valuable than he who holds the empty gun.

Petrol doesn't last forever. Sure, open the can up two years later there's still liquid inside, but chemically it's changed and probalby won't run your car. You're better off "stockpiling" the means to make your own fuel(s) like a home biodiesel or ethanol maker.

And while canned goods will undoubtedly be valuable, it's the folks who have the seeds who grow more food who have the greatest odds of surviving long term.

Stockpiling will carry you over a few months to a year of crisis - but it's the means of production that will enable you to survive, raise children, and continue your family into the future.

(Personally, all I've got is a garden at this point. Well, that and a bicycle, which would be transpiration if the petrol is gone and the cars/trucks aren't usable. Handtools. Oh, and things like spinning wheel and weaving loom, which will come in handy when everyone's clothes start wearing out. If someone doesn't burn them for fuel to keep warm in the winter, first.)