https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...
They bring up Malthus w/o noting that his math was correct --- he just didn't anticipate the Haber process, nor the on-going improvements afforded by foodstuffs from the new world.
The one valid point made is that we are moving ever larger quantities of rock for ever-smaller returns --- when does that reach a point at which it no longer makes sense?
It's worth noting that process is one of the technologies that techno-optimists like to cite to shout down skeptics of their belief we humans will always techno-magick ourselves out of every problem. We will until we can't, and a couple generations after being proven wrong by famine and extinctions, the techno-optimists will resume their chant.
- we are burning up to 10 calories of petrol chemical energy to get 1 calorie of food energy
- we are currently using something like 3 times earth's annual resource production
> countless other finite resources such as water
Water is a renewable resource!
A lot of water used for agriculture in the US is "fossil water" from aquifers that takes millions of years to replenish. The oceans are a limitless supply of water, but like the HB process, require energy to convert to a useful form.
... which is why historically Malthusians have been wrong.
A Malthusian bacterium writing at the time before photosynthesis would have concluded that life on Earth was doomed. Chemotrophic bacteria were gradually consuming all the left over high energy compounds from the Earth's formation and eventually this would run out, leading to a population crash and the end of organic life.
Their math would have been correct.
The thing they are leaving out of their models is adaptation and intelligence. Life isn't guaranteed to always find a way, which is why shorter term stagnations and die-offs do occasionally happen, but given time and resources it eventually will. Life will probably keep finding a way until the heat death of the universe.
The bumps in the road are part of the process. In evolution they provide the constraint that stimulates learning through natural selection. In post-evolutionary cognitive intelligence (humans and eventually AI) constraints give rise to signals such as price signals that tell the system that it needs to learn, change, and adapt.
This isn't a justification for total rose colored glasses woo-woo utopianism because as I said bumps in the road do occur. But it shows why simple Malthusian reasoning hasn't historically been accurate and probably will continue to be mostly inaccurate.
Malthusians are like perma-bears that are always calling for a recession in the market. Occasionally they're right, but there's a joke in finance that these are people who have "predicted 54 of the last 3 recessions."
A prediction method that's wrong that often isn't actually worth very much.
You can blame Malthus for not predicting an efficient way of getting nitrogen out of the atmosphere; this was theoretically possible, the nitrogen was always there, etc.
You can't blame a physicist for computing that 2.3% yoy energy production growth boils off Earth's oceans in 400 years. Thermodynamics is a bitch. Unless a magic future technology turns Earth into a heat pump which can push heat back into the Sun.
Yes you can.
Because baked into this statement is the false premise that energy use (on earth or otherwise. Maybe the concept of energy itself is wrong) would be the limiting factor on economic growth.
Just like how if someone did a simple mathematical calculation on horses would be wrong to predict transportation doomsday, so too wrong the physicist may be for predicting energy doomsday.
That said, if you can figure out how to decouple planetary economic growth - as in, people's lives on the planet getting better, which is the point of having an economy at all, I guess - from planetary energy production growth, I'm listening. I've yet to see an economy-rich energy-poor country; I know that past performance does not predict future results, but we can comfortably say that people need to consume energy in advanced economies to move themselves and goods around, to heat homes and to run their factories and there are certain theoretical thermodynamic efficiency limits to all those things. In some cases, we already have technology operating close to those limits.
Past performance usually doesn't predict future results.
I'm not aware of any good or service that is not subject to diminishing returns from increased consumption. Keep increasing energy consumption and you start hitting other limiting factors like the availability of other resources, labor, population growth, food, etc. Energy can help with some of those but not all of them and not in a linear relationship. Eventually you hit the ultimate limiter: diminishing marginal utility of wealth itself. At some point you start to max out as a human.
There are countries that consume more energy than the USA that are actually poorer and their higher consumption is a function of either climate (lots of HVAC) or the use of old inefficient technology (in which case poverty actually increases consumption).
It really looks like the ultimate limits to growth (on Earth) are demand side limits to growth due to leveling off of population. Humans have fewer kids when they have more wealth and/or see more humans around.
I actually did show it, but I am happy to elaborate and explain further.
A common thing that malthusians do is just take one single metric, then extrapolate it out, and then yell about a doomsday based on that one metric.
One such example is horses. Many decades ago, there were people panicking about an extrapolated line related to horses and transportation.
Cities were supposedly going to fall apart, because of all the problems that an ever increasing amount of horse usage would cause.
We know this to be false, of course, because as our transportation usage increased, we used technology to switch to a new form of transportation (cars), which allowed us to continue to increase our transportation usage, without any of the problems that were predicted via a nieve extrapolated line.
The obvious parallel and point to such an analogy, would be that an extrapolated line based on one single metric, is the wrong thing to worry about because it doesn't take into account that we can switch to a different thing.
So, just like we switched from horses to cars to fulfill increasing amounts of transportation, we also might be able to switch from earth based energy usage, to non earth based energy usage, or to even switch away from the concept of "energy" itself to fulfill increased economic growth.
This is relevant to the topic because I was responding to someone who was also extrapolating out lines a whole 400 years into the future.
Ergo, that's why I criticized and disagreed with the concept of line extrapolation far into the future, which is something that malthusians like to do a lot.
> switch from earth based energy usage, to non earth based energy usage, or to even switch away from the concept of "energy" itself to fulfill increased economic growth.
There's techno-optimism, there's sci-fi and there's... I sincerely hope our need for economic growth can be completely satisfied before we need to move on from energy to something else.
You mean like those panels[0] which radiate heat in specific infrared band in which atmosphere is transparent? We don't need to push energy into the sun, just out of atmosphere into the coldness of space.
[0] https://www.skycoolsystems.com/radiative-cooling-case-study-...
[0] https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
Malthusians assume it won't happen in a destructive, collapse kind of way. They assume there's a wall and the system will mindlessly accelerate toward it and then, on impact, will die.
Malthusians deny the existence of intelligence, more or less. They model life as a non-adaptive physical system.
So how else might it not happen? Two possibilities, both of which could happen: decoupling of energy growth from GDP and continuing of growth off-world.
Efficiency increase could go a long way. We are not even close to efficiency limits for... pretty much anything.
Hard disagree. We're within 2-3x improvement of basically everything. This hardly helps at all if growth must continue.
My argument is growth can't continue and crucially it won't continue...
> That means it won't happen. The question is how it won't happen.
...to the dismay of economists, but I think on that we actually agree.
At some point Earth has to plateau. That's fine except for the fact that all our economic systems depend on eternal number go up. I do think that will be a crisis mid-late 21st century.
My hope is that our civilization doesn't eat itself because banks can't operate the way they're accustomed to operating.
I personally think self-inflicted wounds are a more likely cause for our civilization collapsing than limits to growth directly. We could start to plateau (on Earth at least) and be totally fine but nuke ourselves because we can't deal with the implications for our socioeconomic systems and elect a bunch of populist imbeciles.
Civilisations though...
The Fermi Paradox explodes into a massive tree of possibilities. The truth is we just don't know. We haven't been looking very long or very far, and space is called space for a reason.
Space could be "full" of complex intelligent life, but the definition of "full" for space could be an overall average of one intelligent artifact per cubic light year per million years. We haven't looked around enough to have any chance of spotting that.
Radio SETI is kind of a joke; radiation diminishes with the square of distance so for us to detect a signal from another star it would have to be both intentionally beamed in our direction and incredibly powerful. They'd have to be screaming at us. Anything less than megawatts melts into cosmic microwave background before it reaches even the Centauri system, and anything with complex modulation just sounds like noise anyway.
Long range detection of technosignatures is riddled with assumptions around what to look for. Dyson swarms? If you tame fusion you don't need a Dyson swarm. Megastructures? Those are fragile and unwieldy and lots of small objects might be better. Powerful propulsion systems on spacecraft? It would have to be aimed right at us. Etc.
XKCD has the best Fermi paradox take:
In economics we deal with supply and demand curves. If you price in the emissions, mining will at some point come into equilibrium with demand and continue to supply copper for those essential activities that require it, while forcing alternatives to switch to something else.
For the specific case of copper, aluminum is a close substitute in most practical applications (or CCA composite wires, combining the advantages of both). The world reserves of bauxite seem sufficient for centuries at current rates of extraction. For high end applications like ship or wind turbine use, superconductor motors are becoming a reality.
When asteroid mining is viable perhaps.