They didn't predict what you said they did. They showed a range of possible outcomes based on assumptions, among many. You seem to have picked one outcome as their only one and called it their prediction.
They created a model based on a systems approach whose output depended on assumptions on physical properties of the planet and future human choices. Given the large uncertainties, they ran the model under many sets of assumptions and presented the outcomes.
The point of the book is to illustrate and promote a systems perspective, not just a linear, event-based approach, which you seem to prefer.
Say I agree (at least I get your point ;) - I'm curious how does one test (in the empirical science sense) a systems perspective with regards to predictions / scenario's? Because at least in popular opinion the Club of Rome is known for a pretty grim worldview and political advocacy.
Perhaps I'm too much schooled in traditional economics but Robert Nobel wasn't too kind [1] and even in my environmental economics classes we spent quite some time deconstructing the Club of Rome.
At some point, there are limits to our ability to empirically test large-scale predictions because we have no ability to run history more than once.
This certainly applies to macroeconomics -- how does one empirically 'test' any prediction from a macroeconomic model based on real-life inputs, other than to see what happens? But this shouldn't preclude us from asking the really difficult questions that we care about, rather than restricting ourselves to the realm of physics, where we can get 5 sigmas in classical statistical tests.
With regards to Robert Nobel's criticism, the whole point of the Club of Rome's approach is to model a simplified, 'low resolution' view of the world economy in order to embed it in a larger network of information, goods, and energy flows constrained by the environment -- because the boundary conditions matter a lot to how the macroeconomy functions.
Sometimes you can get away with a much simpler modeling approach if you actually get all the inputs right. The biggest criticism the Club of Rome has on most macroeconomic models is that it doesn't model the environmental inputs in sufficient detail, and these things really matter a lot in the long run.
It is not simply sufficient to take current 'wage levels' or 'capital stock' or even 'level of technology' as a direct input to your DSGE RBC model -- our macroeconomies perform a quasi-ecological function of converting flows of matter and energy, largely taken from Nature and the environment, and converting them further for human use. Understanding the Nature-human interface, then explicitly modeling the stock quantities of the inputs into the macroeconomy must on some level be important, because they are key to how our entire technological society functions.
I you're inclined to learn more about their modeling approach at a high level, I highly recommend Thinking in Systems [1]. Read it a week ago and it blew my mind, as its intuitions match up with a lot of patterns that we see over and over again in dealing with any complex network, but presented in a systematic and convincing manner.
Would it be fair to say that not all their possible outcomes were doom and gloom but that the media seized on that because it gets the most attention?
That being said... we do know that infinite exponential growth of an economy in a finite bounded space is not possible. Eventually it must either plateau or crash. We hope it plateaus. There are some positive signs in this area including most notably the decline of birth rates with development but there is no guarantee those trends will not reverse.
"Infinite" exponential growth at the scale of the universe might be possible, but the distances between even planets (e.g. Earth and Mars) make separate economies at that scale more or less separate systems. We could colonize Mars and continue growth there until that either crashes or plateaus, but that would not impact the growth model of Earth very much.
> "Infinite" exponential growth at the scale of the universe might be possible
Only if the speed of light turns out not to be the hard boundary that it appears to be as of now.
If humanity is bound by any maximum speed (e.g. c, the speed of light), the maximum accessible volume of space is a sphere with radius c * t, where t is the time spent exploring the universe. The volume of this sphere is O(t^3), which is very much not exponential.
The systems part is fine, but if I'm remembering this correctly, they assumed we could arbitrarily convert resources into other resources, which led to some wacky outcomes.
They didn't predict what you said they did. They showed a range of possible outcomes based on assumptions, among many. You seem to have picked one outcome as their only one and called it their prediction.
They created a model based on a systems approach whose output depended on assumptions on physical properties of the planet and future human choices. Given the large uncertainties, they ran the model under many sets of assumptions and presented the outcomes.
The point of the book is to illustrate and promote a systems perspective, not just a linear, event-based approach, which you seem to prefer.