Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Wednesday, April 9, 2014

The Club of Rome all over again

The note by Nafeez Ahmed on the "Nasa-funded paper" (a term that went viral) on societal collapse was followed by a heated debate. In a previous post of mine, I noted how we were seeing again the debate that took place after the publication of the first "The Limits to Growth" study in 1972. Indeed, it is the same debate, complete with the mistakes and misinterpretations of that time.

Let me examine the rebuttal to Ahmed's post published by Keith Kloor. In it, Kloor seeks support for his arguments with a number of external opinion. For instance, he cites Mark Sagoff as stating

"At one point, I skimmed the article yesterday and saw that it was the Club of Rome all over again — the computer that cried wolf. [...] There is nothing here [in the paper] that was not presented in the 1960s and 1970s by Paul Ehrlich and other “Cassandras” as they called themselves.  Their views, repeated in this [Guardian] article and study, have been completely discredited. [...] Nobody learns anything or bothers to try."

I would venture to say that, before criticizing a paper, one should examine it a little more in depth than simply "skimming" it. Indeed, here Sagoff justifies his stance simply on the basis of old legends that say that the views of the Club of Rome "have been completely discredited."

It is curious to note that the term "Club of Rome" is still so often automatically associated with the idea that "The Limits to Growth" study was completely discredited. It is not so, and there is a whole literature which shows how the results of the study turned out to be valid to describe the present situation (*). The "Computer that cried wolf" is just one of the many legends that went viral and still infect cyberspace. Indeed, Sagoff's statement "Nobody learns anything or bothers to try" better describes the critics of the study than its supporters.

Another author that Kloor cites in support of his thesis is Vaclav Smil. Kloor doesn't report what Smil told to him, but we can find Smil's opinion on this matter in a paper that appeared in "Population and Development Review", in 2005, where he criticizes "The Limits to Growth" mainly on the basis of statements of disbelief and on the fact that the model is too simple. To give you some idea of the tone and the substance of Smil's arguments, let me consider the following sentence:

[In the model] Declining arable land still keeps lowering food production, while in the real world there is, globally, an obscene surplus of food as epidemics of obesity affect more and more countries.

Can you see the problem, here? Smil mistakes a parameter for the model. "Arable land" is a parameter of the model. It is NOT the model. And, of course, declining arable land as a parameter has the effect of lowering food production: how could it be otherwise? But the model has other parameters related to food production: energy, fertilizers, technology and more. The result is that food production can keep increasing despite declining arable land. So, the model correctly describes the behavior of food production in the real world (alas, up to now; what will happen in the future is all to be seen). 

It is almost incredible how easy it is to make this kind of mistake even for competent people, such as Vaclav Smil. But it happens all the time: it is the same mistake that William Nordhaus made back in 1973 when he criticized a model similar to the one used for the Limits to Growth. He took a single equation out of the model and showed that the equation - alone - couldn't reproduce the behavior of the real world. Of course: cut off a leg from a frog. Note that the leg, alone, can't jump. Then conclude that frogs can't jump. Impeccable logic. (see "The Limits to Growth Revisited" for details about this story).

There is much more to be said about the "Nasa-funded study" and it is perfectly possible to criticize it for sound reasons. Unfortunately, however, the "debates" on this subject seem to be mainly about showing the power of legends in affecting human minds. And we will see over and over the same position: since we don't like the results of the model, then the model can't be true. We never seem to be able to remember that models are just tools, and never prophecies.

"The Limits to Growth Revisited"
"Looking back on the limits to growth"
"The World model controversy"
 "Revisiting the limits to growth"
.... and many more


  1. A useful reminder about the political history of the "Club of Rome", thanks.

  2. John Baez has an excellent discussion of the paper in the "NASA-funded study" on his blog. Unlike Kloor, who just likes to stir up controversy without understanding, Baez actually explores the model and how it works:

    1. Thanks, Steve. I had seen Baez's post. He is doing excellent work with his blog.

    2. And you too with your posts on the IPCC report!!

  3. its funny how these nutters are bothered by a 'NASA funded study' (since when did being associated with top scientific establishment become a sign of incompetence), but apparently not worried about infinite growth economics. an idea that was never peered reviewed at all or even properly thought through at the most basic scientific level. an idea that small children could easily poke holes in, let alone scientists.

  4. "Of course: cut off a leg from a frog. Note that the leg, alone, can't jump. Then conclude that frogs can't jump. Impeccable logic."

    That's a very good and very 'sticky' analogy. I like it.

  5. My own point of view - which like any other employs certain "mental models" to observe certain realities, pose certain questions, follow a particular method and then arrive at conclusions ...and –like all mental models- is also limited- is that the main reasons why Limits to Growth was "misunderstood" and maligned and continues to be are of a POLITICAL nature. Though personal and professional rivalries and the "defense" of certain disciplines e.g. economics and econometrics in particular, also play a role which easily intertwines with politics. I don't think the technical or epistemic or ontological or theoretical or methodological validity of the LTG Model will ever be able to (on its own) overwhelm or over-ride these political factors. So those political factors have to be tackled on their own account by other POLITICAL means.

    My "proof" for the first statement? The book and its approach and its conclusions are still being maligned and misunderstood today in much the same ways as over forty years ago. And in fact there are now even those who go one step further to say that the book is the "cause" of some of the limits we are now experiencing (we have not been investing or de-regulating enough due to LTG’s presumably dire and wrong- warnings) rather than an explanation of why those limits are manifesting themselves due to the actual dynamics of the world system and of its interactive components and sub-systems. (i.e. the various stocks and flows, and their structure and the positive and negative feedbacks governing them)

    So a good question to ask might be...what exactly is "politics" and what gives rise to it and how can one perhaps try to move away from -or effectively counter- some of its corrupting influences on human thinking and on paradigm and methodology selection in favor of more "technical" or "scientific" reasoning? There is no religion now which will be declaring Limits to Growth a heresy or will try to burn Jorgen Randers at the stake, but the new "powers that be" might keep trying to do something similar by “new” means.

    One perhaps truly "new" element in the overall picture from a “technical” point of view might be climate change. Although "pollution" was a key component of the original LTG model from the outset, I am not sure (and I mean, NOT sure) whether or not it really considered CO2 pollution and the Climate Change it would bring about (and its significant effects on the other sub-systems) as prominently or as clearly as these now deserve to be taken into account.

    In my view Climate Change (as a subset effect of "pollution") "surrounds and envelops" the entire World System (the human population sub-system and its industrial, agricultural and capital sub-systems) and affects how all the key components or sub-systems end up working or not working and how they interact with one another. Whether it can easily be taken into account or not, is a separate question.

    But Climate Change also throws a spanner in the works of the "political system" and of world geopolitics and geo-economics and of "politics" and "culture" more widely and broadly. (also regionally, nationally and locally) So including its effects on the overall dynamic world system and its main sub-systems might be something worthwhile doing or trying to do. “Technically” the models are probably well on track though they and their validity can always be improved. Politically we probably need to do (much) more. And to do that well maybe we also need to understand better and more widely what politics actually is and what gives rise to its many phenomena.



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)