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

Friday, September 22, 2017

The Hubbert Game - Teaching the Science of Collapse

My students playing the "Hubbert Game." It is a simple operational game illustrating the exploitation of a non-renewable resource and the phenomenon of overshoot and collapse. 

In my presentation at the recent Summer Academy of the Club of Rome, I stressed the point that the major stumbling block we face in managing the ongoing crisis is that most people, and in particular policymakers, lack the concept of "overshoot." As a consequence, they also lack the concepts of peaking and collapsing (also in the form of the "Seneca Cliff"). It is not surprising: the idea of overshoot and collapse is a new development in the science of complex systems. It goes back to a little more than 50 years ago when it was proposed first by Jay Forrester. Earlier on, it simply didn't exist.

So, most people think of the exploitation of natural resources in linear terms, assuming that we can continue extracting oil (a physical thing) as long as we have money (a non-physical thing) to pay for it. When depletion is taken into account, it is done only on the basis of oversimplified and misleading models such as the "resources to production ratio." It is something I have termed "Tiffany's fallacy" (the mineral pie is shrinking and most of what's left is in the sky).

The recent summer academy of the Club of Rome in Florence brought back to my attention the need of exposing people to the basic concepts of the dynamics of real bioeconomic systems. Young people who care about the survival of humankind and of the earth's ecosystem know a lot of things, but I noted that they too often miss the concept of overshoot and collapse. That's something that I had already noted years ago and it had led me to develop an operational game called "The Hubbert Game."

The Hubbert game is a simple boardgame that needs no computers and no special equipment except some black and white counters used to mark oil fields. It is designed to be run in a few hours at most and to provide to players a "hands-on" experience of what means to run a company that exploits non-renewable resources. Players take the role of oil companies which compete in exploiting the gradually dwindling oil resources. The game is competitive and some versions involve strategic choices; the game surely tends to capture the attention of the players. The final result is always the same, the pattern of oil production, in the game as in the real world, tend to look like the "bell shaped" Hubbert curve.  You can see the curve below, hand drawn from the results of a game session

The Hubbert game is described in detail in a paper that I presented at the 2016 conference of the System Dynamics Society in Delft, Holland. There is also an earlier version which I uploaded on the "" site. As I keep experimenting, new versions may appear.

In the meantime, the game seems to be enjoying a certain popularity, at least in Italy. It has been used by my colleague Luca Pardi for his class in environmental economics at the University of Florence. It was played in a high school and it is planned for the "night of the researchers" to be held this Sep 29 in Trento. You see here a snapshot of the flyer of the game for that occasion (h/t Luciano Celi and Luca Pardi).

Will this game have some positive effects? Well, in an earlier post I said that we need something like "a new axial age" to develop the tools we need to manage the earth's ecosystem (which includes humankind as an element). So, it is hard to think that a boardgame will save the world. But it is a step in the right direction and, after all, it is fun!


  1. Mr Bardi,

    You have used the overshoot chart several times in the last few posts, but even though it is a generic representation of consumption overshoot, carrying capacity and degraded carrying capacity, the chart has the potential to mislead the unwary. If the chart were to be applied to humans, the overshoot would be many multiples of the carrying capacity, rather than about 40% more as shown.

    I suggest redrawing the chart so that the ratio of peak overshoot to carrying capacity is about the same as the ratio of pre-fossil-fuel energy consumption (as the level of long term carrying capacity) to the rate of present energy consumption. Depending on the historical energy survey, this ratio varies from about 15:1 to 40:1. A ratio of 10:1 would be conservative and more properly illustrate the magnitude of our overshoot. It would show a Seneca Cliff that is much higher and far more precipitous. It would more truly represent the human predicament.

    1. It is a historical chart. I think it was drawn by Jay Forrester, but it can also be found in the first edition of "The Limits to Growth". Maybe it should be drawn in different proportions, indeed, but the idea is there, I think

  2. many thanks, Ugo - Luciano

  3. Prof. Bardi. It is true that over-shoot is a very recent concept for us, expressed explicitly and scientifically.

    However, you may be interested to learn that the concept of over-shoot and consequences arising from it is very clearly found in the legends of Ancient Iran, as preserved in the Shah-Nameh.

    The legend of the First Shepherd says that each time that the human population and their flocks of domesticated animals reached the limits of available land,he used his magical powers- derived from the gods as a gift to Mankind - to extend the Earth.

    And so expansion continued.....

    But, one day, the gods came to him as he was preparing to perform his trick once more, and informed him that this time it would not work.

    They warned him and mankind to prepare for the Great Winter that was coming, and that they should hide in the caves.

    Interesting story: expansion of population through application of technology (gift from the gods which distinguishes Man from other animals), repeated success in extending carrying capacity , then sudden, unavoidable failure upon touching the final limits of carrying capacity- leading to total regression to an earlier mode of existence in a much harsher environment.

    This is very different from other ancient myths narrating a fall from the grace of a Golden Age due to sin and violence on the part of humans.

    1. I know that many things were invented in Mesopotamia long before they were thought of in modern times. This story I didn't know, how old is it?

    2. Well, it is found in the Shah-Nameh which is a repository of all the old tales of Iranian civilisation: written, in fact, to save them and the Persian language from Arabian Islamic cultural domination.

      The 'proto-type prose' version of the poem is believed to date from 957, with written sources from the 6th century AD, but the mythical lore is recognised as being very ancient indeed.

      I certainly sat up when I saw the story! Memories of failed irrigation and farming projects in the region?

    3. You may be interested in this:



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)