When Will Society Collapse Due to Pollution?

[jedishrfu]

A recent article on the Club of Rome 1972 prediction of fast economic growth leading to societal collapse in the 21st century:

https://www.vice.com/en/article/z3x...it-prediction-that-society-will-collapse-soon

 

[jedishrfu]

I remember reading the book Limits to Growth during the 10-week winter trimester at college in 1972. While taking the course, we had to deal with a gas crisis and soaring prices and long lines at the pumps in the snow. It was a mess but when the course ended so did the crisis and we wondered if the prof hadn't somehow created the crisis specifically for the course. :-)

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

The book was derided saying its statistics on world resources was under represented. However, it seems that we would run into this issue sooner or later.

Pulling out my Foundation trilogy (or is that 4,5,6... books prequels and sequels) in hopes of finding the second foundation. :-)

 

[gleem]

You might be interested in the book "Scale" by Geoffrey West which I reviewed in https://www.physicsforums.com/threads/what-are-you-reading-now-stem-only.912884/page-16
He discussed the problem with the Malthusian catastrophe. He does not think that it needs to happen and offers a solution to the collapse of civilization. The TED talk that West gave in the above link is worth watching to get a taste of what the book is about.

 

[Jarvis323]

The model assumes steadily declining resources. Theoretically, couldn't available resources, rather than dying out, continue to grow, probably for billions of years, based on automation together with the industrialization of space? Or is the prospect of getting resources, food, and manufactured items down to Earth from space insurmountable?

 

[phinds]

I sent this to a friend of mine who studies this sort of thing as a hobby. I have always found his analyses of such things to be very thoughtful and knowledgeable. Here are his very quick off the cuff comments.

1. In general, at the time this study was done, the Club for Growth was replete with doom and gloom studies.

2. The article does not give any data or explanation, except for the three graphs (see below).

3. The graphs are very general, with no values on the vertical axis – so it is hard to tell how closely they track current empirical data. Clearly the origin is not zero, which always makes me think the presentation is being manipulated to emphasize a point that the data does not support.

4. There is no explanation for what is driving any of the variables.

5. I don’t know what is meant by “Resources”, but my sense is that the known reserves of almost all resources is at least as large today as it was in 1900, while the graphs in all three scenarios show a dramatic reduction from 1900 to 2020. I think that any model that shows ALL resources being depleted in 80 years is just plain silly. Do they expect that the sun will burn out in that time frame?

6. Perhaps global pollution today is worse than in the 1980s (as all three graphs show) but I am quite certain that pollution in the US is actually better now than it was 40 years ago, and I think this is the case everywhere in the developed world. Even China seems to be getting a handle on pollution.

7. The key variable of the five shown, in my opinion, is population. Most studies I am aware of project world population leveling or declining over the next 80 years (except of course for the RCP85 study used by the UN climate control panel).

8. Setting aside the unexplained substantial variations of the variables over the next 80 years, and only looking at the end points in 2100, I don’t think even the worst case of the three (BAU2) shows the collapse of civilization. It shows the world being back where it was in (the roaring) 1920s. This triggers another of my “hot buttons”: using absolute numbers when per capita numbers are much more meaningful.

 

[BWV]

However, trees do not grow to the sky: 2% per capita income growth over 1000 years is a factor of a billion or so, obviously absurd

we are already seeing stagnation in middle class incomes across the developed world, the dynamic of the last few hundred years of every generation becoming materially better off than their parents has to end.

 

[phinds]

On the other hand

The S&P 500 Index originally began in 1926 as the "composite index" comprised of only 90 stocks.1 According to historical records, the average annual return since its inception in 1926 through 2018 is approximately 10%–11%.[cite] The average annual return since adopting 500 stocks into the index in 1957 through 2018 is roughly 8%.

That's a limited view of things, but still ...

 

[Vanadium 50]

I dragged out my copy. Some comments:

First, it's obvious that exponential growth can't go on forever. Whenever anyone points out that they blew a prediction, someone responds "You moron! You think exponential growth can go on forever?" usually followed by "The Club of Rome was absolutely right! It's just happening later than you think!"

Second, the Club of Rome had (has?) a political agenda. That doesn't make them wrong, but the fable that is told is that "One day, Jay Forrester and his group at MIT were walking along, minding their own business, not bothering anyone and then Blammo! They discovered that We're All Gonna Die!" No, Forester was commissioned to do the study by the Club of Rome. Forrester used Club of Rome inputs. Doesn't make this wrong Does mean the fable is just that.

Third, the new factor Forrester brought to this was a <sense of awe>Computer</sense of awe>. For 1971, this was a Big Deal. It must be right...it was done on a <sense of awe>Computer</sense of awe>. By the standards of the time, the <sense of awe>Computer</sense of awe> was impressive. Today it is less powerful than a cellphone. Probably less powerful than my toaster. To fit in a late-1960's vintage computer, the model was incredibly oversimplifies. "Resources" and "pollution" for example are single variables.

Finally, let's look at a botched prediction. They had us running out of gold in 2000. In 2021, gold is at an 11-year low. What did they get wrong? Gold is about seven times as expensive today, even with inflation factored in. This is due more to political and economic factors (that in fact, began in the 1970's) than running out. At this price, recycling becomes cost effective, so we use less gold. The dominant industrial usage is in plating electronics connectors, and it is up, but not as much as they thought, and not for the reason they thought. In 1968 these were vacuum tube pins. Since then the number of electronic components has gone up by billions or maybe trillions or more and the electronics gold usage has gone up by...drumroll please...about a factor of two.

It would be unfair to call this book hippie propaganda of 1970. But it's definitely a product of its time, both in its slant and its methodology. It's not Nostradamus. Well, maybe it is.

 

[BWV]

On the other hand
That's a limited view of things, but still ...

The 1957-2018 (or 2021) S&p 500 return is over 10%
https://dqydj.com/sp-500-return-calculator/

 

[russ_watters]

However, trees do not grow to the sky: 2% per capita income growth over 1000 years is a factor of a billion or so, obviously absurd

we are already seeing stagnation in middle class incomes across the developed world, the dynamic of the last few hundred years of every generation becoming materially better off than their parents has to end.

I don't find "has to end" any more compelling than "doesn't have to end" or see how a completely unknown limit could be "obviously absurd".

To me, the limiting factor in growth/development/standard of life is the limit of technology. Maximum luxury comes from owning everything that could make one's life better. So as long as those things haven't been invented yet or not everyone has them, there's more to grow.

Or to put a finer point on it: Earth is an open system. Its only known resource limit is the lifespan (times power output) of the sun. Everything else is an argument from incredulity.

 

[gleem]

o me, the limiting factor in growth/development/standard of life is the limit of technology.

You will find that Geoffrey West agrees with you, i.e. with what he refers to as innovation.

 

[Vanadium 50]

The 1957-2018 (or 2021) S&p 500 return is over 10%

Yes, but individual stocks go in and out of the index. By biasing towards survivors, it biases towards winners. Look at some of the original Dow stocks: General Railway Signal, Sears Roebuck & Company, Victor Talking Machines...

 

[BillTre]

I think that it would be useful to consider these "Malthusian" type of limits in cases were they do work, biology.
The idea as used in biology is that, unlimited growth will be exponential (as considered in theoretical realm of mathematical population doublings, and in environments where there are no limiting factors to growth), while growth of resources (food, places to live, etc., is at best linear (real world growth of food)) but could be at an unchanging steady state.

Thus, the doubling population will eventually exceed its environments limits WRT (pick at least one): food, oxygen, waste removal, breeding sites, living sites, others.
These kind of things work well in biology, in the short term.
Over longer (evolutionary) time periods, biology can slowly adapt, by evolving genetically.
Slower, involving many generations, more detailed molecular level changes.
Individual humans (or groups) can ID a problem and, in some cases, come up and implement with a solution almost immediately. This is much faster than evolutionary time and can be observed my an individual in a fraction of their life.
Compared with people, animals are kind of stupid. They can't think up ways to overcome problems in the short term. Only in humans (and perhaps a few other species) have brains large enough, and organized for "higher" thought, enabling them to plan out ways to overcome problems that they personally encounter during their individual life.
This skewing of ability toward humans is accentuated as problems get more complex and abstract.

Animals, on the other hand can come up with new approaches to achieving their goals (reproduction, making more copies of themselves) over much longer (evolutionary, at least several generations) time periods.
These evolutionary changes, result from selection (for reproduction) of those individuals, with a genetic composition that most enables them to reproduce. (Its a tautology, based in the physical world, manifested in chemistry, at a nano-molecular level of organization, and assembled to make larger physical entities.)
It, of course, is slow to make changes (taking many generations), and usually (but not always) works in small steps.
The available changes will largely be somewhat limited by the starting material (the current genome with the generative pieces that its genetic "design" encodes (beyond protein sequences)).
Some changes are a more likely to result of the various mutational mechanisms available, smaller changes are usually favored, but more drastic changes are not fully excluded, just way less likely.

My view is similar to this:

To me, the limiting factor in growth/development/standard of life is the limit of technology. Maximum luxury comes from owning everything that could make one's life better. So as long as those things haven't been invented yet or not everyone has them, there's more to grow.

You will find that Geoffrey West agrees with you, i.e. with what he refers to as innovation.

The steps in a process of biological innovation (adapting to new situations/environemnts) will be a lot like the history of technological development of some kind of equipment or instrument.
In addition, in both biology (as a process) and technology, new functions can lead to a vast array of new possibilities to explore. Over long time periods, this can be an exponential increase of possible new opportunities, or new abilities (functions?), or available environments for doing something in are created.

Over the history of life on earth, there have been numerous examples of changes, which can changes limits on organisms, as well as creating new opportunities for new life forms to take advantage of.

The initial making of cars created new manufacturing niches (which are able to attain the required economic viability for survival), like car radios, tires, transmissions, ..., while endangering competing (horse associated) technologies.
Similar things happen in the biological world, as new species form, modifying their environment (by their presence as food if nothing else), which leads (over evolutionary time periods) to new forms that can take advantage some opportunity for making a living there. (Example; the great oxygenation event: new organism started making oxygen, oxygen level rise (in a billion years or so), older life forms have to retreat to low oxygen environments, chemical changes in seawater result, new forms evolve to occupy oxygenated areas.) If nothing else, a new opportunities for parasites to evolve are generated.

There are not a lot of limitations to biological design, (except maybe physical wheels), but they are ususally slight modifications of preexisting forms (their ancestors). However, new opportunities reveal themselves, building on past advances and can in turn open up new additional possibilities.
I would expect most new engineering designs would be similar to successful ones, that have been used in the past, but the innovations can still occur.

 

[russ_watters]

I think that it would be useful to consider these "Malthusian" type of limits in cases were they do work, biology.
The idea as used in biology is that, unlimited growth will be exponential (as considered in theoretical realm of mathematical population doublings, and in environments where there are no limiting factors to growth), while growth of resources (food, places to live, etc., is at best linear (real world growth of food)) but could be at an unchanging steady state.

Thus, the doubling population will eventually exceed its environments limits WRT (pick at least one): food, oxygen, waste removal, breeding sites, living sites, others.
These kind of things work well in biology, in the short term.

Yes, I do brew beer. Every batch is a universe-destroying calamity.

 

[phinds]

The idea as used in biology is that, unlimited growth will be exponential (as considered in theoretical realm of mathematical population doublings, and in environments where there are no limiting factors to growth), while growth of resources (food, places to live, etc., is at best linear (real world growth of food)) but could be at an unchanging steady state.

It's sometimes surprising how such issue resolve themselves. For example, food production is NOT linear, if I understand it correctly. Modern farming techniques and better seeds have lead to a considerable jump in food production, particularly in the staples such as rice and wheat.

Also, there were predictions in the early part of the last century that by 1925 or so New York City was going to be 3 feet deep in horse s-h-i-t but the auto solved that problem (and then created smog in San Francisco ... things ARE complicated)

 

[BillTre]

When people manipulate biology, non-standard things can happen.

 

[phinds]

When people manipulate biology, non-standard things can happen.

Exactly. I think that predictions such as the one that started this thread are based, to be generous, on faulty assumptions about what "the natural order of things" or "business as usual" is. Such things are often NOT a "natural order" or "as usual" and unforeseen events, over the course of 50 years, throw such predictions completely off.

 

[russ_watters]

It's sometimes surprising how such issue resolve themselves. For example, food production is NOT linear, if I understand it correctly. Modern farming techniques and better seeds have lead to a considerable jump in food production, particularly in the staples such as rice and wheat.

It has always puzzled me that people would expect food production to be linear. Technologically stagnant farming efficiency(output per acre and worker) would be constant, so production output should be a function of...? Population. More farmers = more crops to harvest. The worst case food production model should thus always be tied to population growth, lagging it by, oh, about 16 years. But that still makes the farming output the same shape geometric progression as population.

Technology just increases the efficiency. There isn't even a limiting factor in land area.

My grandfather was a farmer. I'm glad technology has enabled me not to be.

Exactly. I think that predictions such as the one that started this thread are based, to be generous, on faulty assumptions about what "the natural order of things" or "business as usual" is. Such things are often NOT a "natural order" or "as usual" and unforeseen events, over the course of 50 years, throw such predictions completely off.

Yeah. There are many flaws, but one of the more common is a faulty assumption about just how fixed or limited certain resources are...and how fixed the demand is. Peak Oil comes to mind there. It did not foresee that new technology would unlock known but presumed unrecoverable oil. Meanwhile, car fuel efficiency has increased by...50% in the past 30 years? In both cases (resource reserve and demand), technology changes the equation.

...It's even a little worse than that though, as it is common to use "known reserves" in the model, discounting the idea that we aren't looking past current and short term future demand. The models should expect the reserves to grow as demand grows, but they typically assume the reserves are fixed.

 

[BillTre]

There ares some limits, but not currently effective.
For example:

• total amount of energy coming from the sun (plus energy from other environmental sources) available for biological use
• total numbers of available molecules of various elementsavailable for biological use

but we have probably not reached those limits yet.

In fact, we are still changing vast environmental areas over to human use, and thereby possibly expanding food generation.
Of course this affects things like habitat fro wildlife and the biological complexity of environments (humans tend toward more biologically mono-culture.

 

[russ_watters]

There ares some limits, but not currently effective.
For example:

• total numbers of available molecules of various elements available for biological use

but we have probably not reached those limits yet.

That one I struggle with. If human population self-limits (unlike the yeast in my beer), we need not reach a limit of usable biological molecules. Maybe for other resources, but even if every human needs to buy their own Death Star, we would just need to mine Venus and Mars for the raw materials. My wildly speculative point is just to illustrate that even the existence of limiting factors is wildly speculative.

 

[BillTre]

Well, I think a lot of people expect some kind of social limitation mechanisms to kick in, like its too crowded here to raise a family.
Happens with animals too. Pheromones and behavior in crowded situations can result in reduced births.
This could have evolved because more stable populations tend to survive longer. If they don't survive a more stable one could take over later.

 

[russ_watters]

Well, I think a lot of people expect some kind of social limitation mechanisms to kick in, like its too crowded here to raise a family.

Already has, but not because the world is too crowded for offspring to survive. It's because there is more individual luxury in fewer/delayed procration(s). I'm honestly not sure how Darwin would feel about that.

 

[Vanadium 50]

The authors of The Limits To Growth were not idiots. (IMHO, they were wrong, but that's not the same thing). They tried to consider technological developments, and ran models with the resources doubled and "infinite". However, the model is too simple. "Resources" is not a single thing. That's what the s at the end means.

The infinite resource models have the population grow past the maximum with limited resources, so food per capita falls, so you have a population crash. In all three models (standard, doubled, and infinite) this happens about now: say 2015 standard, 2030 if doubled and 2040 if infinite.

 

[BWV]

Yes, but individual stocks go in and out of the index. By biasing towards survivors, it biases towards winners. Look at some of the original Dow stocks: General Railway Signal, Sears Roebuck & Company, Victor Talking Machines...

Cap-weighting biases winners - a pure market cap weighted index has similar performance. Who cares if all the original DOW stocks are still around or not? A stock index should represent the aggregate market values of companies operating at that point in time

 

[BWV]

I don't find "has to end" any more compelling than "doesn't have to end" or see how a completely unknown limit could be "obviously absurd".

To me, the limiting factor in growth/development/standard of life is the limit of technology. Maximum luxury comes from owning everything that could make one's life better. So as long as those things haven't been invented yet or not everyone has them, there's more to grow.

Or to put a finer point on it: Earth is an open system. Its only known resource limit is the lifespan (times power output) of the sun. Everything else is an argument from incredulity.

Certainly tech is a factor, but everything is subject to diminishing returns. The widespread economic growth from the industrial revolution provided radically better material lives for ordinary people, but to the earlier thread, real per capita or household income cannot grow long term at 20th century rates as, in addition to the exponential absurdity of everyone consuming like a billionaire in 3121, that growth encompassed moving from substenance agriculture to getting an industrial job and basics like electricity, indoor plumbing and a car. No future technologies are likely to improve my material standard of living from this point more than running water and electricity did for my great grandparents.

 

[BWV]

I think that it would be useful to consider these "Malthusian" type of limits in cases were they do work, biology.
The idea as used in biology is that, unlimited growth will be exponential (as considered in theoretical realm of mathematical population doublings, and in environments where there are no limiting factors to growth), while growth of resources (food, places to live, etc., is at best linear (real world growth of food)) but could be at an unchanging steady state.

Thus, the doubling population will eventually exceed its environments limits WRT (pick at least one): food, oxygen, waste removal, breeding sites, living sites, others.
These kind of things work well in biology, in the short term.
Over longer (evolutionary) time periods, biology can slowly adapt, by evolving genetically.
Slower, involving many generations, more detailed molecular level changes.
Individual humans (or groups) can ID a problem and, in some cases, come up and implement with a solution almost immediately. This is much faster than evolutionary time and can be observed my an individual in a fraction of their life.
Compared with people, animals are kind of stupid. They can't think up ways to overcome problems in the short term. Only in humans (and perhaps a few other species) have brains large enough, and organized for "higher" thought, enabling them to plan out ways to overcome problems that they personally encounter during their individual life.
This skewing of ability toward humans is accentuated as problems get more complex and abstract.

Animals, on the other hand can come up with new approaches to achieving their goals (reproduction, making more copies of themselves) over much longer (evolutionary, at least several generations) time periods.
These evolutionary changes, result from selection (for reproduction) of those individuals, with a genetic composition that most enables them to reproduce. (Its a tautology, based in the physical world, manifested in chemistry, at a nano-molecular level of organization, and assembled to make larger physical entities.)
It, of course, is slow to make changes (taking many generations), and usually (but not always) works in small steps.
The available changes will largely be somewhat limited by the starting material (the current genome with the generative pieces that its genetic "design" encodes (beyond protein sequences)).
Some changes are a more likely to result of the various mutational mechanisms available, smaller changes are usually favored, but more drastic changes are not fully excluded, just way less likely.

My view is similar to this:
The steps in a process of biological innovation (adapting to new situations/environemnts) will be a lot like the history of technological development of some kind of equipment or instrument.
In addition, in both biology (as a process) and technology, new functions can lead to a vast array of new possibilities to explore. Over long time periods, this can be an exponential increase of possible new opportunities, or new abilities (functions?), or available environments for doing something in are created.

Over the history of life on earth, there have been numerous examples of changes, which can changes limits on organisms, as well as creating new opportunities for new life forms to take advantage of.

The initial making of cars created new manufacturing niches (which are able to attain the required economic viability for survival), like car radios, tires, transmissions, ..., while endangering competing (horse associated) technologies.
Similar things happen in the biological world, as new species form, modifying their environment (by their presence as food if nothing else), which leads (over evolutionary time periods) to new forms that can take advantage some opportunity for making a living there. (Example; the great oxygenation event: new organism started making oxygen, oxygen level rise (in a billion years or so), older life forms have to retreat to low oxygen environments, chemical changes in seawater result, new forms evolve to occupy oxygenated areas.) If nothing else, a new opportunities for parasites to evolve are generated.

There are not a lot of limitations to biological design, (except maybe physical wheels), but they are ususally slight modifications of preexisting forms (their ancestors). However, new opportunities reveal themselves, building on past advances and can in turn open up new additional possibilities.
I would expect most new engineering designs would be similar to successful ones, that have been used in the past, but the innovations can still occur.

But we only care about changes human society can adapt to. The history of humans shows Malthusian limits get reached, then some catastrophe hits (climate change, war, pandemic or whatever) and the society cannot react swiftly enough and population declines something like 30-50%. This occurred repeatedly in Europe and China in premodern times. Industrialization did not eliminate the Malthusian limit, it just kept pushing it out faster than the population grew. Today, most every country outside of Africa has birth rates at or below replacement, so maybe its not an issue, but climate or some other disaster could again create a situation analogous to 14th century Europe where population levels fell 50% from climate change then the plague.

 

[russ_watters]

Certainly tech is a factor, but everything is subject to diminishing returns. The widespread economic growth from the industrial revolution provided radically better material lives for ordinary people, but to the earlier thread, real per capita or household income cannot grow long term at 20th century rates as, in addition to the exponential absurdity of everyone consuming like a billionaire in 3121, that growth encompassed moving from substenance agriculture to getting an industrial job and basics like electricity, indoor plumbing and a car. No future technologies are likely to improve my material standard of living from this point more than running water and electricity did for my great grandparents.

I certainly agree with your last point: if I had the opportunity to show just one piece of technology to an Egyptian Pharoah it would probably be my air conditioner(ehh..maybe a plane, but that's still old by modern timelines). I've also heard the only thing that really improves life when you are mega rich is a private plane. Everything else is just incrementally better. But that point just means there is no need for vast increases in wealth that we can think of. It doesn't mean wealth has to stop growing. Maybe in 3132 we'll all own planet-sized space based solar farms for Bitcoin mining? The super-rich can always find stupid stuff to buy/out bid each other for. .

 

[russ_watters]

But we only care about changes human society can adapt to. The history of humans shows Malthusian limits get reached, then some catastrophe hits (climate change, war, pandemic or whatever) and the society cannot react swiftly enough and population declines something like 30-50%. This occurred repeatedly in Europe and China in premodern times. Industrialization did not eliminate the Malthusian limit, it just kept pushing it out faster than the population grew. Today, most every country outside of Africa has birth rates at or below replacement, so maybe its not an issue, but climate or some other disaster could again create a situation analogous to 14th century Europe where population levels fell 50% from climate change then the plague.

I know we have discussed this before but since we're discussing it here again I'll just briefly restate my disagreement with your position. I do not agree that those examples constitute malthusian catastrophes but even if I did:

1. These are pretty minor catastrophes (which is why they are not what I would normally expect a malthusian catastrophe to be).
2. They are recoverable. Again, not a feature I usually associate with malthusian catastrophes.
3. The significance of these catastrophes is decreasing over time due to development. Maybe they'll stop altogether(or just decrease so much we no longer bother to call them "malthusian catastrophes")? We already agree on why they might.

Somewhat separately, I don't consider external disasters to be malthusian, but again, our ability to both reduce their significance and recover may render at least some of them moot. If a comet the size of Texas cracks Earth in half, that would end us, but I would not consider that catastrophe malthusian.

 

[russ_watters]

3. The significance of these catastrophes is decreasing over time due to development. Maybe they'll stop altogether(or just decrease so much we no longer bother to call them "malthusian catastrophes")? We already agree on why they might.

Actually, there is another reason they are decreasing in significance: scale/connectedness. You considered civilizations isolated when you say one killed '50% of Europe". Today we are so connected that the same catastrophe/civilization could not be as easily categorized as isolated. The denominator gets bigger, and the same connectedness that increases the denominator can decrease the numerator as well.

 

[Vanadium 50]

Yes, I do brew beer. Every batch is a universe-destroying calamity.

I have a friend who is hardcore. Grows his own hops. Even he pours entire batches down the drain.

Also, there were predictions in the early part of the last century that by 1925 or so New York City was going to be 3 feet deep in horse s-h-i-t

Instead, it's knee-deep in lawyers.

 

[phinds]

Instead, it's knee-deep in lawyers.

Same thing, so I guess the predictions were right.

 

[russ_watters]

I have a friend who is hardcore. Grows his own hops. Even he pours entire batches down the drain.

Oh, no, even when it's awful it is still beer, and I made it so I'm going to drink every last drop.

One time I brewed a Pilsner that turned out brown.

 

[Vanadium 50]

One time I brewed a Pilsner that turned out brown.

"the pale stale ale with the foam on the bottom".

The Triple Rock Brewery in Berkeley makes something called Tree Frog Ale. I swear it tastes like it's made from real tree frogs.

 

[Bystander]

"the pale stale ale with the foam on the bottom".

"Old Frothingslosh?"

 

[aheight]

I sent this to a friend of mine who studies this sort of thing as a hobby. I have always found his analyses of such things to be very thoughtful and knowledgeable. Here are his very quick off the cuff comments.

Phinds, no offense but I think your friend did a poor analysis of this study:

1. In general, at the time this study was done, the Club for Growth was replete with doom and gloom studies.

The cited reference refers to a new 2020 study of the original 1970 World3 results done by Gaya Herrington who is an analyst at KPMG, a professional service company providing ESG (environmental, social and governance) impact of business investments. She is credentialed in my opinion.

2. The article does not give any data or explanation, except for the three graphs (see below).

Gaya's paper Updates to limit to growth is cited in the article and it contains empirical data.

3. The graphs are very general, with no values on the vertical axis – so it is hard to tell how closely they track current empirical data. Clearly the origin is not zero, which always makes me think the presentation is being manipulated to emphasize a point that the data does not support.

The graphic data in the plots are scaled to fit on one plot:

It should be noted that the numerical scales of the World3 output differ widely between variables. They are scaled in Figure 1 (as in the LtG books) to fit in one plot. This means that relative positions to each other on the y-axis have no meaning whatsoever. What is relevant is the movement of the variables over time in each of the four scenarios. These movements together depict the storyline of that scenario, which unfolds based on the specific scenario assumptions.

4. There is no explanation for what is driving any of the variables.

The paper cited above, "Updates to Limits to Growth" provides the data used for the analysis in section 2.4. For example, for the population data:

Figures from the Population Division of the United Nations Department of Economic & Social Affairs (UN DESA PD, 2019) were used for this variable.

5. I don’t know what is meant by “Resources”, but my sense is that the known reserves of almost all resources is at least as large today as it was in 1900, while the graphs in all three scenarios show a dramatic reduction from 1900 to 2020. I think that any model that shows ALL resources being depleted in 80 years is just plain silly. Do they expect that the sun will burn out in that time frame?

Section 2.4 of the paper describes resource data such as coal, natural gas and oil.

6. Perhaps global pollution today is worse than in the 1980s (as all three graphs show) but I am quite certain that pollution in the US is actually better now than it was 40 years ago, and I think this is the case everywhere in the developed world. Even China seems to be getting a handle on pollution.

Atmospheric carbon dioxide and plastic production were used for this variable:

World3 assumes pollution to be globally distributed, persistent, and damaging to human health and agricultural production. CO2 concentrations and plastic production were used as proxies

7. The key variable of the five shown, in my opinion, is population. Most studies I am aware of project world population leveling or declining over the next 80 years (except of course for the RCP85 study used by the UN climate control panel).

I cited the source of the population above

8. Setting aside the unexplained substantial variations of the variables over the next 80 years, and only looking at the end points in 2100, I don’t think even the worst case of the three (BAU2) shows the collapse of civilization. It shows the world being back where it was in (the roaring) 1920s. This triggers another of my “hot buttons”: using absolute numbers when per capita numbers are much more meaningful.

Only one of the four models, "Business as usual with a dramatic increase in the pollution variable" (BAU2) suggest "global society would experience a sharp decline (i.e., collapse) in economic, social, and environmental conditions within the twenty-first century."

I think we can agree the proxies used for the "pollution" variable, atmospheric carbon dioxide and plastic pollution will continue to be significant environmental issues: carbon dioxide is the highest it's been in several hundred-thousand years and it's not easily (significiantly) sequestered, and plastic is slow to degrade.