[blake1]

The single most important assumption in this paper is that energy consumption will increase by 2% per year. This kind of exponential growth leads to outlandish estimates for the amount of tidal energy that society will demand.

Energy consumption has decoupled from population growth rates and economic growth.

How much energy will we consume in 1,000 years? Most projections of the population have it stabilizing at around 15 billion. But continuing at its current growth rate (an optimistic assumption I think), gets us to about 150 trillion humans in 1,000 years.

And at 2% growth rate, each of those humans will consume 20,000 times more energy than a circa 2023 human.

Now state of the art technology wastes about 80% of the energy consumed, so this is equivalent to 100,000 times more useful energy consumed per human.

So the physics in this page is a good examination of the surprisingly large compounding effects of unchecked exponential growth.

[RetroTechie]

> The single most important assumption in this paper is that energy consumption will increase by 2% per year.

There's a 2nd big assumption:

That tidal energy extracted is additional Earth's rotational energy loss above what Earth does by itself.

According to the paper, tidal energy is dissipated through friction between ocean water & the seafloor. This dissipated energy subtracts from Earth's rotational energy. And some rotational energy is transferred to the moon (which makes the moon move further out). Ok so far.

Author's 2nd assumption is that as tidal energy is tapped, this is extra energy that subtracts from Earth's rotation.

But is it? It might also be that tidal energy extracted by humans, comes out of some fixed 'budget', and the remainder is dissipated naturally. More tidal energy extracted by humans -> less tidal energy dissipated through ocean vs. seafloor friction.

Kind of like solar influx: it's a huge but (apart from fluctuations) fixed amount. We can tap some % of that potential, but what's available doesn't increase. And what humans don't tap, gets absorbed / radiated out by other natural processes.

I won't even hazard a guess. But it would be interesting to figure out which of those applies.

[onlyrealcuzzo]

It's a bit absurd the idea that humans living on earth are going to produce more energy than the Sun.

Maybe I'm naive and simple minded. But that just seems insane.

If I'm doing the math right, at 2.3% growth = we produce more energy than the Sun in 4500 years.

It doesn't matter how many years it is. It's never happening.

Just look at how damn hot and inhospitable the sun is. We're not producing more energy here!

It'd be infinitely more plausible to build a Dyson sphere around the Sun, and call me naive on that, too, but I'm skeptical that's ever gonna happen either.

[wudangmonk]

Not a Dyson sphere, a Dyson swarm makes more sense and its doable since it can be very sparse at the beginning and grow denser with time.

[mrexroad]

Satellites (points), swarms, rings, sails along a spherical plane (e.g. spherical lune w/ axis along ecliptic)… seems like ”realistic” progression.

In a far-future where a TNG-inspired Dyson structure were somehow feasible (1AU size, habitable surface on interior, etc.), it’d be incredibly disappointing if we applied the (unrealistic) science and (unrealistic) resources towards building such a thing, rather than interstellar efforts. Buuuut maybe I’m just projecting my disappointment with our planet’s current approach to science and resource utilization.

[Nevermark]

100-500 years from now is enough time for AI to develop small nuclear and/or laser sail micro spacecraft that can colonize other systems at a good fraction of the speed of light.

Which would leave 4000 years or so to colonize every system with 1000 light years.

In each system collecting and engineering with low gravity material (asteroids, centaurs, smaller moons, etc.) and using that to capture solar energy will get routine.

Gas giants are basically massive hydrogen nuclear energy depots.

Earth and even our solar system don’t form any kind limit to resource growth on time scales like that.

[SEJeff]

And it’s been said that the mass requires to build a Dyson sphere around our sun would necessitate destroying all of the planets: not gonna happen.

[mnemonicsloth]

The estimates I've seen suggest maybe just Mercury.

Which is good, because Mercury is mostly metal, whereas e.g. Mars is mostly rock and thus not useful for this kind of work

[TwoCent]

Would Mercury be a good candidate, given how far in the sun's gravity well it sits? Perhaps better to start with the asteroid belt.

[hollerith]

>Author's 2nd assumption is that as tidal energy is tapped, this is extra energy that subtracts from Earth's rotation.

Not so. The calculation of the 1031 years is equation 19 and assumes the decrease in rotational energy all goes to human purposes.

The flaw in the OP is the assumption that human consumption keeps rising at .02 per year for 1031 years: we would probably boil the oceans away because of the waste heat from using that much electrical power.

[gumby]

> we would probably boil the oceans away because of the waste heat from using that much electrical power.

Which would slow the earth due to the change in angular momentum

[ricardobeat]

Yes, the assumption seems to be that any energy extracted is in addition to the friction with the ocean floor and continental plates, as those will continue to exist.

[pmontra]

Your observation seems to make sense.

Intuitively, if we extract energy from the tides, tides will be less tall and the speed of water will be smaller. Ocean currents will slow down too.

What I don't know is, less friction on the seafloor means that we would actually make Earth slow down less faster than it would do if left alone?

[Interloper2099]

It’s a bit odd to extrapolate to this level. It’s like thinking, yes, I can set one tree on fire and release energy, but look how crazy it is if all the trees in North America burn at once!!

And currents are also affected by the rotation of the Earth, temp differences, and salinity differences so they might not change dramatically.

[codethief]

> The single most important assumption in this paper is that energy consumption will increase by 2% per year. […] How much energy will we consume in 1,000 years

I keep posting this link here on HN but, once again, it seems very appropriate:

> The upshot is that at a 2.3% growth rate (conveniently chosen to represent a 10× increase every century), we would reach boiling temperature in about 400 years.

https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...

[jl2718]

When the nuclear apocalypse has passed, and the last remaining humans are living underground on mushrooms, somewhere an economist will claim growth using a model updated to include the work done by ants, and somewhere a bureaucrat will update the tax code to collect on it.

[casparvitch]

If HN was reading Murphy the front page would look very different every day

[istjohn]

A global cooling system is easily conceivable. The ISS uses radiators to dissipate heat into outer space. We could do the same. We could concentrate heat with heat pumps and pump hot steam, molten salt, or plasma up a space elevator and radiate the heat away.

Edit: The link points out that in 1,400 years we'd be using energy at the rate produced by the sun and in 2,500 years at the rate of the entire Milky Way. Even if we solved the heat radiation problem, it seems unlikely we'd be able to obtain fuel for our fusion reactors at a sufficient rate given the speed of light and the density of matter in the universe.

[amluto]

There’s no free lunch.

The sun radiates heat like a blackbody sphere with the surface area of the sun and a surface temperature of 5600K or so.

If the Earth were to have a fancy heat pump that radiated the same amount of heat into space, it would need the radiating area times the effective temperature to the fourth power equal to that of the sun. The real killer problem is that your heat pump is subject to the Carnot efficiency of pumping heat to that same temperature.

By the most straightforward Second Law calculation, entropy transferred to hot side >= entropy removed from cold side. So Q_hot / T_hot >= Q_cold / T_cold. Q_cold is the heat removed from the pleasant ~300K place where the humans are. At 5600K on the hot side, 18.6 times as much heat needs to be radiated out, so for every bit of useful work done on Earth, at least 17.6 times as much energy is consumed in cooling. If you want the radiator to be only half the surface area of the sun, multiply that by about 16.

What future humans really need is a Dyson sphere with absolutely enormous radiating area. :)

[anon____]

Well then maybe we should do this at night, i.e. always on the dark side of the Earth, not the one that's facing the Sun. Basically passing through the radiation that reaches us.

[pyinstallwoes]

Like space itself

[naikrovek]

we can (and do) radiate heat into space already. there's a specific infrared wavelength that passes out of our atmosphere unimpeded.

building things which receive sunlight but which emit IR at this wavelength would have a cooling effect, though I don't know to what scale.

no need to pump anything up to space, lol. just put hot stuff inside vessels which are painted with a material which radiates heat at this specific wavelength.

[AstralStorm]

Uh, paint doesn't radiate heat not does it convert IR frequencies. (except for very unusual, usually fluorescent materials) It reflects incident IR.

[naikrovek]

not normal paint, no.

thanks for nitpicking; always appreciated

[bmitc]

> A global cooling system is easily conceivable.

That sounds like a line from Dr. Strangelove by the titular character with ol' Bucky following up with "Mr. President, we should not allow a heat pump gap!".

[nvm0n2]

That's not a great argument by the physicist, the economist definitely won that debate. The physics guy only seems to realize that though when he wakes up the next day and has calmed down a bit.

Although the link is useful for the thermodynamic calculations, there are two major problems with the argument as presented:

1. Right up front the physicist arbitrarily bans space travel. The economist, being an agreeable man who'd probably rather be making smalltalk with a pleasant member of the opposite sex rather than defending his whole profession to a bolshie physicist, accepts this limitation, but he shouldn't have done. Nothing in economics is predicated on a space travel ban. We are already obtaining economic growth from space via satellites and that era has barely got started. None of the physics arguments work if you make the relatively small leap to putting factories, power plants etc on moons, asteroids, space stations or other planets. This doesn't require colonization assuming progress in robotics.

2. Much more seriously, the physicist doesn't understand what growth or wealth mean in an economic context. The economist tries patiently to explain this to him many times, and he just doesn't get it. This is a very common problem when talking about economics because people aren't used to the expansive definition of wealth economists use, so often conflate it with other things like money or (in this case) energy.

You can increase wealth indefinitely even with a stable population and stable energy/resource usage. This isn't controversial or weird, it's just part of how wealth is defined. The VR example is one attempt, dessert another attempt to explain this to him, but he just doesn't get it until the next day when he suddenly has an epiphany but decides it wasn't his fault because he personally distinguishes between "growth" and "development". No such distinction is recognized by actual economists for valid reasons. But you don't get to claim there's a problem with economics just because you failed to understand the lingo of the field.

[dTal]

If that's "wealth", then "wealth" is worthless.

When you have a capped number of humans, and every last one of them is jacked into the Matrix and has everything they could possibly want - what is there left to grow? If the growth in "wealth" doesn't actually reflect an improvement in human experience, then it's a pointless term. Sure you can have two computers trade virtual tokens at an ever-increasing rate until you saturate the network cable, but calling it "wealth" is an exercise in semantic subterfuge.

It's like saying economic growth is unbounded because you can always print more money. Eventually it has to bottom out in something real.

[nvm0n2]

I think you're arguing at cross-purposes with me. Nobody has argued that bouncing virtual tokens around creates wealth. That's the "wealth is money" fallacy that I just criticized.

Wealth as used by economists just means all the goods and services that we provide to one another, sometimes with the addition of "services" like a clean environment. It's very broad and includes things like cultural wealth, and doesn't even have to involve selling something.

That's why printing money doesn't create economic growth and nobody claims otherwise. In fact in the debate they specifically agree to discount inflation to avoid it getting in the way.

[dTal]

The point is that there's no such thing as a (meaningful) good or service that doesn't require some amount of a tangible and finite physical resource - human time, if nothing else.

The economist's position - and yours, apparently - is that "growth", whatever it is, can be sustained literally infinitely, on a finite rock amongst a finite group of hairless apes where nothing about the actual situation is infinite. So you can either have a highly abstract definition of "growth" that allows this to be true, or a definition that most people would recognize as meaningful or positive, but not both.

[nvm0n2]

Be careful here - the economist's position about a finite world was something the physicist picked. The economist agreed to it early on, probably to try and seem agreeable, but it's not a reasonable concession to make. Space exists, we put things there today, presumably will put more things there in future. So there is no finite world.

But let's make the same assumption for a moment. For economic growth [of wealth] to stop requires two things to stop: population growth and productivity growth. As GDP is roughly population * productivity.

Clearly, populations can stop growing or shrink. We can also assume a finite population limit. So this is an argument that productivity growth is also finite. But, why should that be the case? Take the example of computers. Modern computers are much more productivity enhancing than older computers, but they are also smaller (i.e. less physical resources needed) and more energy efficient. Even if the Earth had reached carrying capacity, smarter chips would continue to be designed and the productivity boost of computers would keep increasing. That's just one example, there are many others.

But again, the finite world assumption doesn't hold. So the whole debate is a bit of ivory tower silliness anyway.

[joak]

This boiling temperature conclusion makes the assumption that we continue using thermal power (steam engines, etc...), where waste heat is around 60%.

However photovoltaic and wind does not produce much waste heat. Arguably solar and wind cannot scale 1000x but then you could have non thermal fusion like Helion's https://www.helionenergy.com/technology/.

Btw, thermal power is already showing limits (rivers overheating in summers), we don't have to wait 400 years to see its failure.

[codethief]

> This boiling temperature conclusion makes the assumption that we continue using thermal power (steam engines, etc...), where waste heat is around 60%.

No, it doesn't. The waste heat, at the very end of the day, is always rather close to 100%. I.e. we use all that electric energy we generate to power computer, fridges, and many other machines, all of which – sooner or later – convert that electric energy to heat. (And, well, maybe a bit of chemical binding energy, depending on the application. But then, a few decades later, those products of our work will usually fall apart and/or are being burnt or torn down.)

> you could have non thermal fusion like Helion's

No, you can't. As the author says:

> this statement is independent of technology. Even if we don’t have a name for the energy source yet, as long as it obeys thermodynamics, we cook ourselves with perpetual energy increase.

Free free to have a look at his other article (the one he links in the paragraph above) for some more details -> https://dothemath.ucsd.edu/2011/07/galactic-scale-energy/

[XorNot]

100% of the heat we get from the sun is currently lost as waste heat, by one means or another. So you're not boiling the oceans by any reasonable projection of energy usage increase of solar energy.

(yes yes some of it is reflected back into space as non-IR light, but you can also lose IR-emissions back into space without heating the Earth as well).

[codethief]

Most of that incoming heat is reflected / radiated off actually. It doesn't "stay" on Earth.

https://en.m.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

[XorNot]

That is literally what I said.

[midasuni]

Where does the energy go then? EM radiation leaving the planet?

[joak]

Chemical energy. Like the plants, they take sun energy and store it as chemical energy. We could do the same, take CO2 and water and make CH4 and oxygen (electrolysis + Sabatier reaction) and make plastic. Or take ore, aluminum oxide and iron oxide, and "unburn" them releasing again oxygen (we already do that) etc...

We mostly use energy to manufacture things.

Life takes energy and lowers the entropy of the planet. Why shouldn't humans able to do the same? Any technical reason?

[AstralStorm]

There are limits to doing this, which is why we find it really hard to, say, remove CO2 from the atmosphere.

The technical reason is called entropy. Diffuse heat is hard to concentrate and use, much like gas outside of a container.

[codethief]

> Life takes energy and lowers the entropy of the planet. Why shouldn't humans able to do the same? Any technical reason?

Reducing entropy necessarily produces waste energy + entropy elsewhere. So the technical reason this cannot be done at the planetary scale is called Second Law of Thermodynamics.

Yes, we could try to put all that excess entropy & heat into space but there are limits to that (Stefan-Boltzmann law, among other things).

[dredmorbius]

The lesson that constant percentage (that is, exponential) growth cannot continue endlessly is the fundamental message behind the concept of Limits to Growth. That is, there exist intractable limits to growth, and that no matter how convenient it may be to pretend otherwise, humans ignore this fact at their extreme peril.

Long-term ongoing economic growth, expressed as a constant percentage, is baked in to most current orthodox economics and economic policy. Even apparent mavericks such as Thomas Piketty assume that growth will continue interminably (noted in Capital in the Twenty-First Century).

Rather than being a critique of Liu, you've actually written a criticism of those he himself is generally addressing.

[kbenson]

> Long-term ongoing economic growth, expressed as a constant percentage, is baked in to most current orthodox economics and economic policy.

Whether it is or isn't, the optimal strategy for a nation is likely exponential growth until it can't, and then switch as quickly as can be done with the least problems.

Since nations are competing, and we're talking about exponentials here, the cost for cutting off exponential economic growth too soon is likely to become irrelevant to the future, which every nation is going to strive to avoid.

[dredmorbius]

One problem with "grow quickly, then switch", is that it often leads to high-growth institutions, factions, ideologies, and infrastructure.

Countries which grow quickly bake those assumptions into financial, industrial, economic, and political policies. They create companies, regulatory bodies, and financial systems which are predicated on growth. They create economic ideology and the mechanisms for promulgating it which are founded on growth. They create development patterns (most especially of urban land use --- the most massive impact of the automobile was on city and suburban landscapes), and consumption patterns.

Once entrenched, those are all exceedingly difficult to dislodge.

I'd argue that China is wrestling with this now, and that a fair bit of the disruption of the past few years (above and beyond exogenous shocks, notably Covid-19) involve this, as the CCP attempts to wrest power back from industrial, financial, and real estate interests.

Some European countries (notably the Netherlands and Amsterdam with its bicycle- and transit-centric transport planning), Japan, and possibly others such as Costa Rica, seem to have followed a lower-growth curve. These may actually find transition more viable.

At the capital of capitalism, the United States, transition faces absolutely massive obstructions in the form of politics, politics-expressed-as-social-values, economic interests, finance, real estate, land use, transportation, building codes (residential, commercial, and industrial), and more. Those are far more significant obstructions than actual technical solutions, and the more illuminating advocates of sustainability that I follow tend to emphasize this.

(I'll list these later, though I'm still waiting for XorNot to cough up. I'll give them a few more hours.)

[kbenson]

I don't deny that it's likely an exceedingly had thing to do, to transition, and that it's likely harder the longer you wait, just that when you're dealing with exponential growth that opting out too early is likely disastrous in it's own way.

I think it's a mistake to assume stability in nations and a strong self governing community between them can be assumed at all points in the future, especially if there is some stop to exponential growth at some point (but not only because of that). Economic power is somewhat fungible with mitary power, and lack of power in a possible future less stable system of nations could be very problematic.

In short I think the safest and most conservative path for any nation to protect it's future is to take advantage of as much growth as it safely can for as long as it lasts.

Another way to look at is that is the U.S. was to opt out of growth right now, how long would it take for us to become irrelevant on the world stage, and how long after that before we were (and our citizens) negatively impacted by trade deals because of lack of leverage (which is probably a best case scenario of negative possibilities IMO). It's the job of a government to avoid that scenario.

Transitioning is hard, but I'm not sure it's harder than the alternative, depending on how far out we are to it being forced on everyone.

That said, I'd be happy to read whatever info you have on the topic to expand my thinking.

[dredmorbius]

One of the counterarguments to exponential growth, particularly in the context of limits, is that growth rises to some constraint. What the country with a higher nominal GDP growth rate does is ... hit that limit sooner rather than later. We've seen countries go through tremendous growth spurts: the UK ~1800 -- 1914; the US ~1870--1970; post-WWII Japan 1945--1990; the "Asian Tigers" of South Korea (particularly contrasted with the North), Hong Kong, Singapore, and Taiwan 1960-2020; and most significantly of all, China 1990--2020. But each of those eventually hit a wall and saw vastly diminished, or no net GDP growth.

To that extent, "rapid growth" seems largely a matter of "reaching your ultimate potential earlier". And the post-rapid-growth phase turns out to have ... interesting challenges: environment, politics, demographics, and more, many of which emerge after sheer growth alone can no longer paper over conflicts or issues which had been present all along.

There's also of course the argument that GDP doesn't measure actual net wealth or common weal, which is a criticism that dates back to the origins of GDP/GNP, and even its creator, Simon Kuznets. There are numerous alternative measures that are proposed. One aspect I've not seen much addressed is that GDP is largely a tool for managing macroeconomic monetary dynamics, that is, as total monetary exchange grows or shrinks, then the monetary base itself must be adjusted, which is the remit of central banks. Those banks can create or destroy money at will (pursuant to policy goals and prime directives), because money itself is not wealth. The knock-on effects are felt profoundly in asset markets, that is, goods or securities whose principle or significant function is to serve as an inflation-resistant store of wealth: stocks, bonds, real estate, precious metals, collectables (art, wine, cars, etc.), and the like. Asset value inflation is not itself economic productivity. It may reflect economic productivity (that's at least the fig leaf covering stock markets), but far more often, asset inflation simply follows national and global monetary policy, most especially rising in times of loose money or easy loans (largely equivalent terms). John Kenneth Galbraith's The Great Crash 1929 remains an excellent post mortem of one such event. To that extent, measuring GDP growth alone provides distorted view of actual wealth growth, both at the level of individuals (say, median, bottom quintile), and of net national power and stability, though of course how distorted is the stuff of legendary disagreements.

There is a history of countries burning through growth potential with immense rapidity, most especially in the case of natural resources extraction. Instability in the Levant following the mid-2000s has been tied to loss of net-exporter status among oil producers (Syria, Egypt, Libya), as well as food scarcity through both climate-related crop shortages and reduced imports as oil revenues decline. One of the more spectacular cases is the Pacific island nation of Nauru, which underwent a birdshit apocalypse after (briefly) highlighting as the world's richest nation (per capita) after what proved to be a highly limited resource reached its limits. <https://www.nytimes.com/1995/12/10/world/a-pacific-island-na...>

The country's recovered somewhat by entering into the hospitality business. That is, it runs internment camps for the refugees Australia would prefer to pretend don't exist and sends elsewhere: <https://devpolicy.org/nauru-riches-to-rags-to-riches-2021041...>

To the extent that contemporary economies run on the basis of extraction (petroleum, coal, natural gas, minerals, groundwater, topsoil) and sink exhaustion (the ozone layer, heavy metal contamination, greenhouse gasses, plastics and endocrine disruptors, habitat and species disruption, ...), none of which are costed into either market transactions or national wealth/income statistics ... well, we're all on busses headed toward various cliffs, some nearer, some further.

One option is to expend resources on things which presently have relatively low value but would be exceedingly useful in a post-carbon / post-collapse society. That includes basic skills, sustainable practices, sustainable infrastructure, and the social patterns which can effectively utilise these. Keep in mind that this runs directly contrary to market signalling as markets have an overwhelming present-bias in assigning values, as anyone caught holding the bag after a crash can tell you. Potential future utility simply isn't considered, and in general, non-market mechanisms seem to be required to encourage such investments.

(There are other systems which similarly fail to consider long-term value, and it's long been a favourite trope to note the immense ecological contamination and pollution which occurred in the Soviet bloc. However similar desecration was seen both earlier and simultaneously under market systems ... both are poor at delivering ecological equity. Ultimate reforms have tended to emerge through social movements, legislation, and legal recourse, none of which are market-based.)

My final argument is that much of the advantages attributed to economic growth can be had at relatively low levels of same. That is, equity and distribution count for far more than total gross production or consumption. Invest in infrastructure, healthcare (with a strong emphasis on basic access and preventive measures rather than heroic interventions), education, affordable housing, social safety nets, and sustainable development of transport, built infrastructure (at individual building, community, regional and national levels), resource preservation and enhancement (e.g., water, soil, forest, and wildlands cultivation), actual productivity, mitigation of undesired consequences, and the like, and ... I think you might see a path which whilst it might not register on mainstream metrics is actually preferable over the long run.

[kbenson]

Thanks for taking the time to write such a large and thorough reply. Unfortunately, there's so much in there and multiple of the things I want to express touch on multiple of the points you made, any reply I make is going to be rambling and possibly hard to consume, but I'll make an attempt.

> One of the counterarguments to exponential growth, particularly in the context of limits, is that growth rises to some constraint.

This is an interesting concept, and depending on what we believe fuels growth is obviously true to a greater or lesser extent (mostly greater, in my opinion). It's obvious that resources fuel growth, and different countries have different kinds and amounts of resources, so those eventually being tapped means loss of at least one fuel of growth. Population also fuels growth, but there are obviously limits there (even if people often can't agree on how and when they will express themselves), such as living space and ability to source food.

At the same time, there are things that fuel growth (in this case whether we're talking about GDP or some more holistic metrics of citizen wealth or well-being) such as new technology, whether it be spurred advances in the hard sciences or soft. Political, organizational and social technologies are not to be underestimated here I think. A change on society that causes a marked decrease in psychological problems such as depression, or increase in happiness in some other way, would be immensely important.

In the end though, the technological changes are probably hard to hoard for the benefit of one nation over the other (even if adoption of something that seems extremely beneficial doesn't often happen on short time frames), so the things that cause growth that are limited resources at likely the important thing to focus on. It seems fairly obvious to me that different nations already have different amounts of these resources or the ability to grow them, and will hit those limits at different times.

In the end though, it may not be what matters, as while there are countries of different relative potential, there's also growth through current relative power. Powerful countries can achieve better terms in trade with others by leveraging that power, so the more powerful you are, and the sooner you can bring that power to bear, the more benefit it brings you. In this way, being economically more powerful than others is itself is a form resource to be tapped for more growth.

> ere is a history of countries burning through growth potential with immense rapidity, most especially in the case of natural resources extraction.

To be clear, my argument is not necessarily to grow as quickly as possible (I think that's obviously non-optimal given the negative repercussions and the unknown time at which growth becomes capped), but to continue to try to leverage resources into growth when still possible as fast as is safe (which is obciously complex and hard to do and a moving target).

In large I think that means countries should keep doing what they're doing. IU also think ecological sustainability should be more emphasized, but I don't think that is antithetical to what I just said. We should attempt to grow as much as we can, but pay close attention to the consequences and try to minimize the negative ones. Hopefully that means we're also paying attention to any eventual slowing of cessation of a lot of growth drivers and planning for what that entails as we near it.

> My final argument is that much of the advantages attributed to economic growth can be had at relatively low levels of same. ... Invest in infrastructure, healthcare ...

That investment is where I would like to see a lot of the growth funneled into. The quicker we grow in ways which do not exacerbate those problems, the more resources we'll have to put towards solving them. Ultimately, in a perfect world that might mean picking the areas of growth that have the most bang-for-the-buck to leverage that towards actual problems for people (because it's easy to abstract this away to countries and just say let's get more people which will drive more growth), to make individuals happier, because otherwise why are we bothering.

That most of these decisions are made by large machines that often work through emergent behavior that is hard to steer is not lost on me, and I understand most my arguments are academic and ivory tower in nature.

Finally, thanks for including a large supplementary comment of sources. I'll be adding them to the stack of things I should read (but unfortunately rarely allow myself time for). I truly appreciate it.

[dredmorbius]

On sources: I'm highly partial to the work of William Ophuls who's been writing on this topic for a half century. His PhD thesis was published in 1977 as Ecology and the Politics of Scarcity (with an update in the early 1990s). That largely lays out the problematique, both in terms of resources and political dynamics. The book's old enough that many of its own projections can be tested, and I think these hold out exceptionally well, particularly in highlighting the (then future) rise of China as a global economic, political, and military force. Ophuls has gone on to suggest at least the framework of solutions, most especially in Plato's Revenge (2009), though that remains fairly high level. What really makes Ophuls's works tremendously valuable is his bibliographic notes which are comprehensive and, to use a favourite word of his, synoptic. The note for Ecology in particular covers much of the previous several decades' literature on growth and perspectives from both optimistic and pessimistic viewpoints, and Ophuls is exceedingly fair in considering both. I've gone back to many of those sources myself (Maddox, Kahn, Simon) to compare notes. I've actually typed out the note from Plato's Revenge, which captures a sense of his practice, though that focuses more on recent and political topics: <https://web.archive.org/web/20230607050023/https://old.reddi...>. In that sense, Ophuls is an excellent entry point into the literature as a whole. He has a website at <http://www.ophuls.org/William_Ophuls/Home.html> though in various states of disrepair.

Ophuls's political-ecological approach is being carried on by Thomas Homer-Dixon: <https://homerdixon.com/writing/>

There are other authors: Bill McKibben's Eaarth (sic), Joel Magnusonn's The Approaching Great Transformation, the book Natural Capitalism by Paul Hawken, Amory Lovins, and L. Hunter Lovins, all of which I have to hand. Vaclav Smil has written his own damned library on resources and sustainability from a technical perspective, largely looking backwards though with some forward-looking elements. I particularly recommend Energy in World History (1992, 2019) and Energy and Civilization (2017). Energy Transitions (2016) tackles the specific question of converting to a sustainable-energy path: <Energy Transitions>. And there's a long list of other Smil publications.

Kate Rayworth's Doughnut Economics is another prescriptive work looking at ways forward. <https://www.kateraworth.com/>

The original Limits to Growth (Meadows, Meadows, Randers, & Behrens) remains relevant, and is freely available online: <https://donellameadows.org/the-limits-to-growth-now-availabl...>. I strongly recommend reading primary sources over hot takes, interpretations, and commentaries. It's also helpful to remember that LtG served not as a prescription but as an alarm: there's a clear problem and we've got to wake up to it. Sadly, more than 50 years onward, that alarm continues to be ignored by many (including within this thread).

The now-defunct Worldwatch Institute published an annual State of the World publication which was an anthology of articles on sustainability generally, from 1984--2017, and give an excellent sense of the breadth and progress of thinking on these topics. Those are mostly available via the Internet Archive: <https://archive.org/search?query=worldwatch+institute+state+...>

Worldwatch's founder, Lester R. Brown, has written numerous books, his latest covers this topic, The Great Transition: Shifting from Fossil Fuels to Solar and Wind Energy <http://www.earth-policy.org/press_room/C68/market_forces_dri...>

Looking at the energy picture alone, there's David MacKay's Sustainable Energy Without the Hot Air, which breaks down the technical picture, with a focus on Britain though applicable elsewhere, clearly and soberly. Freely available online: <http://www.withouthotair.com/>

That's just skimming the top of a huge literature. There are a tremendous number of different viewpoints, of topics and approaches, and of course disagreement. Contrary to the assertions of some, however, there are specific and actionable recommendations to be found. Looking into the bibliographies and notes of the works listed should launch you further in whatever direction you care to explore.

[theskypirate]

Japan essentially reached full stagnation in the 90's and has continued to stagnate to the present day. Transition simply happens and society adjusts.

[dredmorbius]

That's part of it.

Japan also consciously entered on a relatively lower-energy path than the US, largely through energy and vehicle taxation and licencing practices, though there were others. That's not to say Japan doesn't have a large number of automobiles, or a strong automobile sector. It does.

But domestic autos tend to be smaller than those made for export elsewhere, there's a tremendous domestic transit system (famously the Shinkansen), and Japan's electronics industry (with hits and misses) was the result of a deliberate government-directed policy toward more efficient resource utilisation over simply mass consumption.

Not perfectly achieved, by any means, but a contrast to policies elsewhere.

[2358452]

> Since nations are competing, and we're talking about exponentials here, the cost for cutting off exponential economic growth too soon is likely to become irrelevant to the future, which every nation is going to strive to avoid.

I question this definition of relevance. To me, relevance is having a healthy, happy, sustainable society and culture. It's not accumulating goods and energy consumption in a self-destructive and planet-destroying way. The sooner nations realize this, the better.

[kbenson]

It's entirely relevant when your country can't control is own future, as that will extend to its citizens. Just because we're in a relatively stable period of history with regards to one nation seeking to conquer another (somewhat bucked by Russia) doesn't mean that will necessarily persist.

A well regulated and lawful country where your rights are respected both internally and internationally is a luxury of a powerful nation and a stable system of narions. The former is what I'm saying is is important with regard to growth, because the latter can't be assumed to always exist in the future.

[dredmorbius]

The question of stability is an interesting one.

There's a long-standing observation that countries in which stable political, economic, and technological cultures have emerged have tended to have natural defences. The British Isles and Japanese archipelago in particular both avoided successful foreign invasion or even significant attack for nearly 1,000 years, until the 20th century.

Contemporary stability has more to do with Superpower alliances than geography, though geography still matters. The grand central-European plain had been the parade ground of invading armies since before the Mongol invaders, but today is largely peaceful, so long as one looks underneath the NATO umbrella. Ukraine suffers not only flat geography, ready river and sea access, railway infrastructure, and a long and unrespected border with Russia, but status as an unalligned state, whose prior security treaties with Russia have been abrogated.

The first four factors are common to numerous other states, it's the last which has proved critical to its history since 2014.

And such alliances don't require especially robust economic capability. Among the 31 members of Nato are wealthy states in absolute (Germany) and per-capita (Liechtenstein) terms, but also some of the poorest, notably Montenegro at 75th worldwide per capita and ranked 46 of 50 among European states in overall GDP (2023). Albania, Croatia, Estonia, Iceland, Latvia, Romania, and Slovakia are other states with low overall or per-capita GDP:

  State     GDP EU rank   GDP/capita (WW)
  -----     -----------   ---------------
  Albania:           40              101
  Belgium:           12               18
  Bulgaria:          26               73
  Canada:           n/a              n/a
  Croatia:           29               54
  Czechia:           19               37
  Denmark:           16                9
  Estonia:           35               38
  Finland:           18               15
  France:             3               21
  Germany:            1               16
  Greece:            22               39
  Hungary:           24               51
  Iceland:           37                6
  Italy:              4               25
  Latvia:            34               50
  Lithuania:         30               44
  Luxembourg:        27                1
  Montenegro:        46               75
  the Netherlands:   7                12
  North Macedonia:   42               92
  Norway:            13                3
  Poland:            10               49
  Romania:           17               55
  Slovakia:          25               45
  Slovenia:          31               34
  Spain:              6               29
  Turkey:             8               53
  United Kingdom:     2               22
  United States:     n/a             n/a

Notes:

- I've listed the North American members, but omitted their GDP as these are not European states.)

- EU rank is 1--50 inclusive.

- GDP/capita rank is 1--134 within Europe, based on global IMF rankings of 192 states worldwide.

Sources:

- GDP overall: <https://en.wikipedia.org/wiki/List_of_sovereign_states_in_Eu...>

- GDP/capita: <https://en.wikipedia.org/wiki/List_of_sovereign_states_in_Eu...>

Takeaway: Alliances trump GDP or per-capita income.

[kbenson]

Yes, but my worry is that what looks like a trend is but a small part of a larger cycle. We've seen what happens when complex political alliances fail with WWI (even if they were more a web than an overarching umbrella), and Ukraine problem was not just that it was unaligned, but that it was choosing to align itself.

How sure are we that the trends we see during periods of somewhat large economic growth (on average, overall for most nations) will continue when that environment is not the same? As more and more countries enter the end/modernity stage of economic bootstrapping (and China and India did), what pressure does that out on nations already at that level?

More than NATO I think trade agreements keep the world together (and drive membership of NATO) as codependency might as well be formalized. If some of that codependency goes away, and countries decide to protect and encourage local sectors (which might be more feasible in a low growth environment, I'm not sure), do the other relationships stay the same?

I'm not claiming to have answers, but I do have a lot of questions and see a whole lot of unknowns.

[xg15]

I think there is one escape from this, basically confining more and more "growth" to artificial numbers on paper (or in a DB).

Cryptocurrencies are kind of going in that direction, where the "value" that is reported as economic growth doesn't correspond to any kind of real-world matter or activity, but is simply assigned to some specific group of bits.

I can kind of believe that this virtual kind of growth could continue a long time without boiling the planet, but of course that doesn't make things less absurd, as the "value" would represent nothing objectively useful and would have to be maintained artificially - either through scarcity mechanisms like PoW etc, or through locked-down devices and ecosystems.

So that kind of "growth" could go on forever without burning the planet but would probably be a step back for civilization.

[dredmorbius]

The problem with this, or any other hypothetical "decoupled growth" argument is that, well, it's purely hypothetical.

There's no evidence whatsoever that economic growth can be decoupled from resource, and most especially energy, usage. There are instances of increased efficiencies, which thanks to the Jevons Paradox increase overall resource utilisation (economically, efficiency is equivalent to a reduced price, and hence induces greater demand). And there are instances of outsourced resource utilisation (both in terms of inputs and of waste sinks), most notably that of China which has committed tremendous domestic resources and incurred immense environmental insult in providing "cheap goods" (that is: goods lacking fully-costed externality impacts) to developed countries.

But there's nary a trace of actual empirical evidence of substantive decoupling in the real world. Much handwaving and could-be's, however.

[snowwrestler]

It’s only hypothetical in that the future hasn’t arrived yet. Most predictions are hypothetical by that criteria.

We know the economy is decoupled from physical limits because we have built it to be that way. If you go to my bank right now, they are not going to have a physical pile of valuable objects there which is my account balance. They have a computer that stores numbers, and obviously it needs energy to operate, but it doesn’t cost 10x energy to store 10,000 instead of 1,000 in the database entry for my account balance.

[dredmorbius]

Qing Dynasty China had "decoupled" its currency from specie by way of the first paper-based currency I'm aware of. See: Richard von Glahn, Fountain of Fortune: Money and Monetary Policy in China 1000-1700 (1996).

But that has absolutely nothing whatsoever to do with decoupling the actual economy from its physical foundations. Long after Qing, China remained fundamentally dependent on rice and wheat harvests (and suffered tremendous population losses, as much as 8 million deaths) many centuries later.

The wealth-tracking representation has been decoupled from any substance with intrinsic value, but the economy has not.

Put another way: you could have a monetary system in which currency was entirely backed in precious gold and silver, and introduce huge quantities of same to your economy ... without increasing the actual wealth of the nation by Adam Smith's definition, "annual produce and labour of the nation". This was precisely the situation Spain found itself in following its conquest of the Americas and importation of vast quantities of South American gold and silver.

[snowwrestler]

> The wealth-tracking representation has been decoupled from any substance with intrinsic value, but the economy has not.

If you insist on measuring the economy solely in terms of "substances with intrinsic value," you will find the limit of economic growth at approximately the limit of those substances. However this is begging the question because it's not the only way (and not the currently accepted way) of measuring economies.

Anyway, it's not just the representation, wealth itself is increasingly nonphysical and hypothetical. For example not only is my $1,000 bank account just a database entry, my database entry is most likely offset by about $900 in loans to other people. So my saved cash is actually about 90% claims on future payments by other people. Or look at stocks; at a P/E of around 20 currently, 95% of the value of my SP500 index fund is hypothetical. And of course the whole point of a bond is future payments.

Market-winning behaviors are also becoming less physically correlated. Did Barbie take 5x as much energy as The Flash to make or present? Does a 3 bedroom row house in San Francisco use 5x as much energy as a similar house in Detroit? Does Apple use 3x as much energy as Amazon? Does it take twice as much energy to make a Mercedes C class as a Honda Accord? There are tons of examples like this. Rice and wheat harvests are a pretty small part of modern economies now.

Look, I agree that a certain level of energy usage is required to enable economic activity. If we were to cut our energy use too much, we would limit or perhaps crash the economy. People need food, clothes, shelter, plumbing, communications, etc. I'm just saying: that is not equivalent to proving that future economic growth is bounded by energy usage. One does not logically follow from the other.

[XorNot]

Conversely the people who argue against growth never have any answers they want to elaborate on. They have "well we can't have endless growth" and that's where the conversation stops.

They never want to examine the consequences of that thought (no growth means we're into a zero-sum game) or whether they think we're even plausibly close to the limit (instead they want to have a proxy argument about environmental damage or global warming, and are very uninterested in any specific solutions to their go to examples - i.e. "we can't possibly stop emitting CO2 from power generation, we must simply use less power!").

[salawat]

...No crap it's a zero-sum game! We've been screaming it from the bloody rooftops while economists and charlatans have gone on and on chasing alpha, instead of really focusing on breaching the most critical breakthroughs we need. Near limitless clean power, closed cycle industrial processes, and bloody innovations in either transport, agri-husbandry, or medicine.

But no.

War. War, real estate, and more pretend finance for finance sake. Either that or mass producing the tools of tyranny.

[XorNot]

You have just given a list of achievable technologies which would allow growth within the current resource constraints. What do you think "new energy sources" are if not economic growth?

[bliteben]

At some point unlimited growth would mean the heat death of earth. Remember all used energy no matter how green the source emits heat.

Even stars have limits to their energy. If you don't believe in limits then you aren't accepting physical reality.

[kbenson]

The optimal strategy now for unlimited growth and some future limit on growth bei g hit when there are competitors are likely the same. Take advantage of it as much as possibly for as long as possibly.

Given two countries where one lints it's economic growth and the other doesn't, if they're given another few hundred years before a limit is hit, which one is in a better place to respond when that limit is hit? Does the country that minutes itself even still exist as it did, or was it taken over by a stronger one (whether economically, militarily or culturally)?

[dredmorbius]

I'd really like to see you point to specific instances of this.

I could point to any number of examples refuting this, but really prefer you lay your cards on the table first.

[XorNot]

I mean you're doing that right now. You seem to believe we can't have infinite growth. Okay...and? Do you have anything more to add other then a mathematical reductio ad absurdum talking about 1000 year timespans? What tangible actions and economic model do you believe this should inform in the next 5 to 10 years, which you as a citizen of a democracy have some role in choosing and advocating for?

[dredmorbius]

Again, I'd really like to know who specifically you are referring to with "the people who argue against growth never have any answers they want to elaborate on".

I've mentioned numerous specific examples refuting that here: <https://news.ycombinator.com/item?id=37399144>

[snowwrestler]

Constant percentage economic growth is possible indefinitely because the economy is made up.

It’s like saying “you can’t imagine a bigger number than I can.” A person can always imagine a bigger number, and the marginal cost of doing so is merely what is necessary to store the larger number in a ledger.

[Turskarama]

If you want to define growth as cash, then sure. If you want to define it by tangible output, then not so much.

[snowwrestler]

The economy is measured in money.

[Turskarama]

"Real GDP", which is the one usually reported on, is already adjusted for inflation and is usually reported as a percentage (i.e. it is unitless).

What this means is that if 100% of growth comes just from inflation then "GDP" will have increased but "Real GDP" wouldn't have.

[snowwrestler]

Growth rates are expressed as percentages. The underlying value, GDP, is measured in money.

[dredmorbius]

Money is itself a measure.

Money is a measure of wealth, it is not wealth itself. Much as a ruler is a measure of length, not length itself.

The ability to measure 1,000 km does not equate to the capacity to travel 1,000 km.

The ability to measure a hectare of land does not equate to the possession of a hectare of land.

The ability to measure a year's worth of labour productivity, or industrial output, does not equate to the realisation of a year's worth of productivity.

And financial units absent the goods and services that they can access ... are worthless.

[snowwrestler]

Money is a measure now.

For most of human history, money was itself physical wealth, or constrained in proportion to physical wealth. Which in turn constrained the maximum value of any good or service it could buy.

Now goods and services can grow as valuable as we ever want them to be. They can even be imaginary. That's how a few thousand smart people at Apple who produce nothing physical can be considered nearly 6x the value of ExxonMobil and the tremendous amounts of land and resources it controls.

[dredmorbius]

<https://news.ycombinator.com/item?id=37386222>

[felipeerias]

> Long-term ongoing economic growth, expressed as a constant percentage, is baked in to most current orthodox economics and economic policy.

As a forecast which may or may not happen? Yes.

As an actual outcome that has been decided a priori? No, not at all. Only planned economies tried to do that.

[slt2021]

it is possible to have exponential growth with a brief period of financial crash/recession, when prices reset to previous bottoms and exponential growth continues (boom&bust cycle).

so far it has been the case with human economics across all countries/economies. yes some shareholders will be zeroed out during recession, but others will continue on the growth journey

[dredmorbius]

That's known as a boom-bust cycle.

It's common in finance and population ecology. See, e.g., lynx-hare population dynamics.

[bobthepanda]

The UN has revised peak projections down several times; the peak is now expected at 10 billion.

[coldcode]

More countries are now sub-2.0 replacement, China is down to 1.09 so the peak is unlikely to get much more than that.

[jl6]

The trends are mostly encouraging but there are still 102 countries with a fertility rate above replacement rate, so we’re not out of the woods yet:

https://en.wikipedia.org/wiki/List_of_countries_by_total_fer...

[crote]

2.1 is the replacement rate for well-developed countries. It does not apply universally to all countries.

For example, the US had a fertility rate of 7.0(!) in 1800 and saw no significant population growth due to births because most of those kids died well before reaching the age of reproduction.

Historically, fertility rates have always dropped once basic standards of living have managed to get rid of excess child mortality.

[XorNot]

Unless those countries have increasingly western lifestyles, stable political systems and growing economies, then it actually doesn't matter. The grim reality is that all those places have substantial modifiers on their death rates, and aren't exporting their increasing population to the world in any meaningful way.

We know from experience that if those places actually started to improve, then the birth rate would drop precipitously.

[ido]

You mean less than that? But more importantly, after that peak comes a long and steady decline (as far as we can tell).

[popol12]

A Google search for “china children per woman” gives me 1.705

Are you talking about something else ?

[smcin]

The Google hit China TFR 1.705 for 2023 is bogus (and 2023 isn't even over yet, which should have alerted you), it's single-sourced from macrotrends.net which is quoting an old (pre-pandemic) UN forecast; you can see from their graph their (forecasted) numbers for 2020-2 turned out totally wrong. Lots of other sites are quoting the Google and macrotrends as fact. So now the #1 Google hit on that is misinformation. (Always look for attributions and dates).

As to 2022, China did briefly drop to a TFR of 1.09, like GP said [1]; but the moving average over several years is more like 1.3. You have to put the 2022 drop in context that their very strict lockdown went into its third year, and there were two cases of pregnant women losing their babies e.g. because the hospital denied them entry for having negative Covid tests but a few hours too old [2].

[0]: https://www.macrotrends.net/countries/CHN/china/fertility-ra...

[1]: "China's fertility rate drops to record low 1.09 in 2022- state media" https://www.reuters.com/world/china/chinas-fertility-rate-dr...

[2]: https://fortune.com/2022/01/07/china-covid-cases-miscarriage...

[anonylizard]

Its now dropping even lower in 2023, long after the lockdowns have ended.

Turns out the East Asian style of hyper-competitive child rearing has its downsides, namely the high costs dissuade parents from having children altogether.

China faces every antinatal problem the west does, except far worse.

1. Extremely high housing prices making family formation expensive

2. Small apartments suppress large family formation (Seen in Europe)

3. General collapse of marriage rates due to changing incentives and thus moral norms

4. Higher education decreasing fertile years.

5. Economic depression, especially for young people, euro debt crisis level of youth unemployment.

You add to that, that China still officially has a 3-child policy (not that many people even have 2), because the birth control bureaucrats still need a job.

China is probably 2nd lowest in the world behind South Korea, and will stay there, if not

[smcin]

When a country makes the one-way generational jump(s) from a TFR of 3 to 2 and then sub-2, and to a post-industrial economy, a bunch of near-irreversible changes set in, from cost inflation and scarcity of education, expectations of years of education and marriage, apartment size etc.

Scott Galloway (and others, like Elizabeth Warren) have been saying this, about the US, repeatedly: US education costs rose (or at least, were allowed to rise by the politicians who were nominally regulating them) by 1400% since the 1970s [https://www.profgalloway.com/inflated/]. This was not sensible policy but if GDP growth via financialization of (third-level) education etc. is your economy's chosen indicator, it's what you get.

Anyway the low TFR is not necessarily a demographic crisis, it's up to the country whether it lets its population decrease (Japan, China), or uses immigration to sustain whatever its target population growth is (US, Canada, EU, SG, Aus).

> 2. Small apartments suppress large family formation (seen in Europe)

You're getting the direction of causality wrong: apartment size was a reaction to the decrease. Contraception, more years of education and other social changes were the drivers of smaller apartment sizes, not the effect.

[bobthepanda]

Education is even worse than that. Education itself is highly competitive even down to the pre-K level in some places.

[popol12]

I gotta admit I don't fact check google's promoted numbers, thanks for demonstrating that I should :)

[happymellon]

Normally it requires two people to make a baby. So 1.7 is less than the number of people requires to create it.

Rates are normally calculated by couples. 0.85 per person is a decline.

[paulmd]

Leave it to HN to be unaware of the physical or social mechanics of reproduction

[istjohn]

I suppose that would be replacement rate if there were 42% more women than men in China. But according to Wikipedia there actually 4.5% more men than women.

[quotemstr]

Almost every human population is under strong selection pressure towards having more people. This dip in fertility cannot and will not last.

[deepsun]

Unless external factors kick in, like depletion of resources and soils. There's no any law of nature that says homo sapiens must be able to survive. Smaller scale examples are:

1. Easter island -- we, humans, deforested the island, that degraded and depleted human population significantly even before the first european ships discovered the island. From what I've heard, "Rapa Nui" movie is unusually historically correct on the events.

2. St. Matthew Island -- 29 introduced reindeer rapidly overpopulated the island and ate all the available food there, so the whole population died.

Same thing can happen on planet Earth.

[mullingitover]

> Easter island -- we, humans, deforested the island, that degraded and depleted human population significantly even before the first european ships discovered the island.

More recent research shows that this is probably not true - there's evidence that the population was growing right up until the arrival of Europeans[1].

[1] https://www.sciencedaily.com/releases/2021/07/210713090153.h...

[crote]

Then why aren't people in countries with plenty of resources breeding like rabbits and are we actually seeing a decrease in fertility once people get access to proper healthcare and sufficient food?

It is almost like humans are not mindless animals who solely reproduce because of biological urges or something.

[istjohn]

The future is Amish

[api]

20000X the energy of a current human shows how absurd it would be for growth and energy use to not decouple. I can’t even imagine what I could do on Earth using that much power. Fly my own 737 to a new city every day?

I suppose spacefaring humans might use that kind of power but if they are living in space they are no longer part of the biosphere of Earth.

[ben_w]

> I can’t even imagine what I could do on Earth using that much power. Fly my own 737 to a new city every day?

Sure, why not?

It's absurd today for the average person, but it's the kind of thing rich people get to do already, and looking at the rich today is a decent (though imperfect because inflation and invention don't work like that) hint for what normal people can afford in a richer future.

[mattmaroon]

Aviation historically, has not gotten cheaper overtime. If anything, it is more expensive. Only rich people had planes 100 years ago and only rich people own them now and the trend line doesn’t indicate it’ll be different in another hundred.

[ben_w]

Nobody owned a 747 a hundred years ago.

Cheapest flight I've ever taken was 9.99 from Berlin to London — not sure if pounds or euros, but does it matter when either way it is less than I used to spend on a week of school lunches nearly 20 years earlier?

[paulryanrogers]

Exceptions like 10 EUR flights aren't sustainable. They're just auctioning off empty seats to cut costs.

The comparison was conceptual thing to similar thing. Only the rich own and operate private planes, that hasn't changed. The fact that other, more sophisticated planes exist doesn't undermine the point.

There are also diminishing returns. And past leaps in lifestyles aren't guaranteed to continue the same trends, and can reverse.

The earth has seen several major extinction events. Arguably humans are the cause of the latest one. Doubtful we can sustain billions of us without an ecological system to produce our bare necessities, certainly not enough for a full life.

[megablast]

> They're just auctioning off empty seats to cut costs.

No, they are selling off seats that aren't taken. They are making more money since those seats would be empty.

Cutting costs would not be selling the seats and saving on fuel.

[Dma54rhs]

European cheap airlines have shown these prices are indeed sustainable for the last 20 years now?

[rodgerd]

> Fly my own 737 to a new city every day?

That's literally the billionaire lifestyle.

Meanwhile cryptocurrency is seeing decades of power efficiency undone as miners bring old power plants online and want to burn tyres to power their scams.

[asah]

Consider modern use of energy vs ancient, and the ancients couldn't imagine our factories, power plants, data centers, etc. Now consider the crazy compression of energy in the conversation to LED lighting.

In the future, we might use a lot of energy for the we cannot imagine today.

In the future, we might stop using every the way we do today.

In the future, we may produce and consume substantial energy in places other than earth's surface.

In the future, the concept of energy itself might be different, much like people couldn't imagine the type of energy involved in nuclear fission.

[cryptonector]

With this analysis no energy source is renewable, and we'd even run out of sunlight (or surface area that can be dedicated to solar power anyways, or see demand exceed solar power were we to put solar panels on every square inch of the planet's surface).

In reality we're already certain to hit a population maximum in just two+ decades, and not only that but the world is very likely to be on a negative population growth curve after that for some time. And we're going to need some new tech revolution to drive energy demand in developed countries up much more than it is, and the developing world's per-capita demand will not likely exceed the developed world's once fully developed.

I.e., we're not growing forever, the end of population growth is around the corner, and the end of energy demand growth is not much further.

[svnt]

> gets us to about 150 trillion humans in 1,000 years

I realize the big issue is settled here but just to scope this detail: the total land area of earth is coincidentally approximately 150 million km^2

At 150 trillion humans each human would get just about a square meter. Many of those square meters are uninhabitable.

[midasuni]

That’s about the density of Kowloon walled city. And ignores the available space in the ocean.

[woobar]

Did they grow any food, produce electricity, or had any manufacturing at all in Kowloon?

[throwaway2037]

To be clear, "Kowloon" is different from "Kowloon Walled City". And, yes, they did have very small manufacturing inside.

I highly recommend that you find a copy of this (in)famous book about it: << City of Darkness>> (https://cityofdarkness.co.uk).

[ChuckMcM]

Extrapolation is always a bad thing :-). That said, this guy has some interesting thoughts. Of course he misses out that if you pump the tides you can speed up the rotation of the earth and thus "renew" the lag (think moving your legs while swinging).

Similarly solar isn't renewable because at some point the Sun is going to run out of hydrogen, and if you made a dyson sphere to capture all of the Sun's energy you would wipe out life on earth.

[solalf]

Peak human population is expected to reach 10.4B in 2084 and slowly decrease from there. This is according to the UN[1] but other estimates envision a much earlier peak by the 2040s at 8.5B followed by a sharp drop to 6B by the end of the century[2].

[1] https://www.un.org/en/global-issues/population

[2] https://earth4all.life/news/press-release-global-population-...

[bufferoverflow]

1000 years is a loooong time. It's entirely plausible to have trillions of humans, if we create conditions for that. And not only on Earth.

For that to happen we need almost complete automation, which would provide cheap food, cheap housing, cheap healthcare, and lack of worry about the immediate future.

Even if you can sustain 1% increase in population per year, 1000 years of prosperity will result in

(8 billion)*(1.01^1000) = 167673 billion = 167 trillion people

(1% is roughly the current population growth, but it's slowing down)

[sidewndr46]

If you assume 2% increase per year, anything is irrelevant. Nothing can allow humanity to sustain unbounded energy growth on a single planet.

[georgeecollins]

15 billion as a stabilized population of the Earth is actually a very high estimate. Some estimate the curve will flatten at 10.5bn. But it is all a prediction, so who knows.

https://en.wikipedia.org/wiki/Projections_of_population_grow...