"That is, regardless of the physical amount of any given resource exists in the world, it is possible to have the entire supply necessary to meet human demand." Wow, this is a bold assumption. If that would be true, why is there a shortage of gold for everyone's palate of gold decor?

For many resources that can't be owned, governments often institute licensing fees and taxes to implement artificial scarcity. This is the basis of things like carbon taxes and "cap and trade" systems.

@antipattern There is no shortage of gold. Demand for gold decor is very, very low because gold is expensive, and most people are not willing to pay for gold decor when gold is expensive. Thus, we still have gold available for complex electronics, precious jewelry, and all sorts of other things that people value more. "Shortage", especially in the context of "unsustainable growth" implied by the question, is a question of whether there is any gold at all for anything.

This is basically the point I was trying to make in my answer. I think you said it better.

Let's one-up you : The claim that The claim that constant economic growth within a planet of finite resources is impossible is false. is false. Mostly : economic growth has always been related to a growth in energy demand. And energy production is finite in our world. dothemath.ucsd.edu/2011/07/can-economic-growth-last

@EricDuminil growth in energy demand creates new technology to exploit energy sources that already exist. The total available energy input to the earth's economic systems (i.e. solar) is about 5000 times the current world energy consumption. The available power from nuclear fusion is so many orders of magnitude higher that for any practical purpose it is infinite. But so far, there has been little incentive to find ways to use energy that are more efficient than burying plants in the ground for a few million years and burning the residue from their decomposition - i.e. fossil fuels.

@EricDuminil alephzero is right. And we're already decoupling economic growth and primary energy consumption. An historic correlation is not the same as an unavoidable causality.

@alephzero: That's nice, in theory. The current power production from nuclear fusion is exactly 0W and photovoltaics covers less than a 1% of the world energy consumption.You're correct that there's no direct incentive to use an alternative to fossil fuels. Our whole civilization is completely dependent on oil, and when we'll finally realize that we really need to switch, it will be much too late. Because we'll still need fossil fuels to change anything. dothemath.ucsd.edu/2011/10/the-energy-trap

@EnergyNumbers: the ratio between economic growth and primary energy consumption has increased by +0,8% per year since 1960. (jancovici.com/en/energy-transition/societal-choices/…) The problem is : this decoupling cannot be infinite. Which would be needed in order to cut the link between economic growth (supposedly infinite) and energy consumption (definitely finite).

@EricDuminil we can have (and indeed, several countries already have had) economic growth with reductions in primary energy consumption. Perhaps reading blogs isn't the best way to learn about these things after all?

@EnergyNumbers: I'll ignore the irrelevant and unfounded personal attack. Please note that those blogs are written by engineers or researchers, working in environmental science, and the posts include links to credible sources. My comment also agreed (a bit) with you : the GDP/energy_consumption has been increasing in the recent past. The burden of proof is still on you, though: you're claiming that it can be infinite. Please feel free to read dothemath.ucsd.edu/2011/07/can-economic-growth-last and find the flaw in the reasoning. It's only a blog post.

@JaredSmith Thanks. I liked your answer too.

@EricDuminil Your criticism is invalid because "energy" is not a resource. It's produced from resources, which are and can be rationed by the price system such that it is not necessary to consume every single drop of oil that exists on Earth. Also, arguments from authority are never valid, but if you're going to use them, you should consider getting some from economists after the year 2012. There's this thing called "hydraulic fracturing" that none of these posts seem to have accounted for when talking about how oil is going to vanish in the future.

@Joe: So oil reserves magically became infinite thanks to hydraulic fracturing? Given that more than 90% of our energy consumption is from fossil fuels, it doesn't seem too wrong to say that energy is a resource. On the other hand, saying that an infinite growth is possible in a finite world is wrong by ∞.

@EricDuminil No, oil reserves became "magically infinite" because oil has a price that changes as supply and demand changes, and that price makes human beings change the patterns of their consumption and production of that resource. The "magic" here is that the physical quantity of a thing is not the same as the economic quantities supplied or demanded, so things in the world can be economically infinite while being physically finite. Also, oil = energy is invalid because we use oil for more things than just energy (e.g. plastics and pharmaceuticals) and have other ways to get energy.

I think your claim of infinite is a stretch. Practically infinite maybe (I mena, larger than most can concieve of), but infinity is bigger than that. Infinity runs into the finite possible state space of matter within the volume of the Earth; ascribing each configuration an arbitrary GDP, and there will be an upper bound. I guess you could become Bach, and have the definition of GDP change, so that each moment thinks it is richer than the old one, then invent a new definition of GDP, increase its value, then go back to the first definition and cycle in a fake ever-increasing cycle.

@Joe: There is also very little demand for gold decor because it's usually just plain tacky. (See e.g. Mar a Lago for an example :-)) There seems to be plenty of gold for things like electrical contacts in computers.

@antipattern: What "controls" the demand is price. If there is less of X, but still a high demand for X, sellers of X raise the price until demand falls for X. If X demand is inelasitic, the high price of X motivates more potential sellers to invest in R&D to find a equivalent substitiute for X, and thus the economic system can (so far) continue despite the scarcity of any one resource X. As the amount of gold increases in price due to increased scarcity, semiconductor manufacturers will be motivated to research other ways to connect electronic components.

@Yakk You may substitute the word "practically" for the word "economically" in my answer if it helps you understand my point, which is that physically infinite supply is not necessary to have all that is required to meet all current demand for items that can rationed with a functioning free-market price system.

Based on how you've defined "satisfying everyone's demand," if there were only enough food for 5% of the population, you could say that so as long as it's priced high enough, everyone's demand is satisfied, even though 95% of the population is starving. I think "sufficient to satisfy everyone's demand" is a vacuous and misleading statement; it seems to say that everyone's needs are being met, but that's not guaranteed at all.

@MiCl If you assume the economy is totally stagnant, that the economic supply of food at any given moment is fixed permanently forever at only enough to feed 5%, then your criticism would be valid (which is not the scenario posed in the question). When prices are allowed to be high, additional sources would be found to solve the problem (either by growing more in the long term, or through trade, or something else). Usually when there's a famine in modern societies there is some additional interference in this process (e.g. British government stealing Irish cattle during the potato famine).

@joe We aren't that far away, exponential growth style, from reaching radiative capacity limits on energy use. Lifting the world to (say) USA levels, then a century or few of growth, and we are talkinh boiling the oceans (ignoring carbon/greenhouse gasses; just raw energy use). In the short term (a few decades) this isn't a problem, but in the medium term it is.

@Yakk That assumes that a growing world economy will necessary continue to require exponential increases in energy consumption for centuries. As EnergyNumbers pointed out earlier, we've already had economic growth with reductions in energy consumption. It is also ludicrous to call "a few centuries" "medium term" because it's abundantly clear we don't have enough information to predict what the economy will be in that time scale (the Industrial Revolution isn't even 3 centuries old yet!)

@EricDuminil Are you sure that renewable sources apart from photovoltaics aren't (indirectly) using solar energy? If I grow crops to burn them for energy, I'd guess that a good amount of the energy came via the sun.

@sgf: You're correct. Wind, biomass and hydropower are all using solar energy on a relatively short timescale. For that matter, fossil fuels also come from solar energy. The power delivered by the sun on Earth still isn't infinite, though. It's possible to power the world with only renewable energies (by definition, you just need to wait for the non-renewable energies to get depleted). It doesn't say anything about an infinite economic growth, though.

@alephzero I guess that if you declare that 5000 is equal to ∞, you definitely can have an "infinite" economic growth, yes.

@EnergyNumbers: Could you please explain what your arguments are if you want to prove that a constant economic growth is possible with finite resources (in particular, energy)?

That is, regardless of the physical amount of any given resource exists in the world, it is possible to have the entire supply necessary to meet human demand. What about overfishing, unsustainable logging etc. There's a point at which these resources won't replenish.

@henning The caveat I gave for the price system was things which are ownable under a free market system. Logging is relatively easy because you can set up tree farms and not run out of wood. Fishing is harder because it's hard to "own" fish the way people own cattle. We can run out of these things, which is why we can use non-price mechanisms to prevent their overuse (e.g. government regulation).

@Joe I generally agree with your answer, but the caveat comes so late that the claim I quoted sounds quite absolute, especially since I believe concerns about natural limits to growth are about the global 'commons' that are per definition hard to own.

@Joe: "A few centuries" is a long time indeed if you're trying to predict random numbers generated by Wall Street servers. It's a very short scale for astronomy, geology and biology, though. And those are the relevant fields when talking about energy, resources and climate. If you think that 300 years is large enough to be considered infinite, you might want to modify your answer.

I am afraid that the reasonning "lack of ressources creates price incentives to reduce demand and/or find new ressources, and so capitalism can sustain infinite growth in a finite world" is only true when the demand is elastic. When/if food ressources get scarce, people cannot eat less than a certain amount just because food is expensive, so reducing the demand would mean dwindling the population, and probably a long-term economic recession.

@Eric Duminil the field of human knowledge about resources and scarcity is economics, as is the field about what human behavior and industry will be is three hundred years in the future.

@Evargalo Why do you assume that food is inelastic? You also aren't limited to eating less, but you can also produce more or trade for it. Also there is a lot of obesity in the world today because governments subsidize food prices; lots of people could probably eat less without having to have famines that kill millions

@Joe: Regardless of what economists would like to think, not all sciences are created equal. Physics need to obey mathematical laws and economics need to obey physical laws. If physics say that an infinite growth isn't possible in a finite world, not a single economic theory can change anything about it.