The Roman Philosopher Lucius Anneaus Seneca (4 BCE-65 CE) was perhaps the first to note the universal trend that growth is slow but ruin is rapid. I call this tendency the "Seneca Effect."
Showing posts with label system dynamics. Show all posts
Showing posts with label system dynamics. Show all posts

Wednesday, March 13, 2013

The World is a Fountain

Originally published on Cassandra's legacy Wednesday, March 13, 2013

The world is complex, variegated, convoluted, multi-faceted, interconnected, complicated, circuitous, and more. And, yet, there is a logic in the way it works.

Look at the Trevi Fountain, in Rome, it is complex and variegated, but in the end there is a logic: water always goes down. It is physics: it is the gravitational potential that makes water move.

The same is true for the whole world. Lot's of things are going on, but there is a logic: energy goes down, it degrades, it is a chemical potential driven by the second law of thermodynamics.

So, no matter how complicated the Trevi Fountain is, water always goes down. No matter how complicated is the world, chemical potentials always "go down."

This is the idea at the basis of the paper that I published in "Sustainability", titled "Mind-Sized World Models." as part of a special issue dedicated to the 40th anniversary of "The Limits to Growth"

The term "mind-sized" comes from the ideas of Seymour Papert, who said that models should be simple enough to be understandable, if one has to act on them. On the basis of this idea, I tried to put together simple, "mind-sized", models which can still tell us something of the way the world works. World Models, in short.

So, I build these models as if they were multi-level fountains, one basin, two basins, three basins, and more.

Each basin represents a stock of energy, which is dissipated in steps, going from top to bottom (in energy terms). It is a concept that I already described in a post of mine titled "Entropy, Peak Oil, and Stoic Phylosophy" but that now I examined more in depth.

Now, imagine a multi-level fountain; imagine that it is dry at start. Then put some water in the top basin. It will go down, step by step, until it reach the bottom basin, and then disappear falling on the ground. It is, in the end, what we have been doing with fossil fuels; burning them until they disappear as they become atmospheric pollution.

Here is the model for the "three-level" fountain. It is the one that gives rise to the "Seneca Effect" (When things go wrong, they go wrong fast)

This is the model that originates the "Seneca Cliff" that we may also call "collapse" and that we may experience at some moment in the future.

My paper in "Sustainability" is "open access". Here is the link

Wednesday, June 13, 2012

Seneca's cliff goes iPad

originally published on Cassandra's Legacy on Wednesday, June 13, 2012

My post on the "Seneca cliff" has inspired Hannes Rollin to create an App for the iPad that can be used for running the model for different input parameters. I must confess that I don't own an iPad, so I can't test the model, but it seems to me a very interesting idea. So, here is the story, with many thanks for Hannes for his interest in my work.

Guest post by Hannes Rollin

Many of you who are reading this post may be familiar with one or the other of Ugo Bardi's mind-sized models, where he employs system dynamics to illustrate fundamental economic and natural processes in a general way. The model which impressed me the most was the one Ugo called Seneca's Cliff – a very simple model capable of generating an economic decline much faster than previous growth had been, a fact already remarked by Seneca. Hence the name.

I give you a quick summary of the model. You have three stocks (imagine them as containers), namely Resources, Economy and Pollution. Now, a given fraction of Resources is extracted and used to run the Economy. Subsequently, a fraction of the Economy spawns Pollution. The flow is furthermore dependent upon degradation or restoration (negative degradation) of each stock. If you ever asked yourself where the nice curves come from, here is the answer: The content of the stocks is plotted against time.

Ugo tweaked the parameters to give a Resource depletion and Economic activity curve very similar to one of the more famous outputs of the WORLD3 model of the Limits to Growth team. I have set this result as the default settings of the iPad app.

The interesting thing is that the model can evolve scenarios quite distinct from the standard run above. If you model a renewable Resource stock with negative resource loss rate, you get a (potentially infinite) sequence of boom-and-bust cycles similar to H.T. Odum's simulation of locust pests.

Although this run looks catastrophic as well with long periods of almost zero economic activity, it already maintains two highly optimistic assumptions: First, resources are strictly renewable no matter how much strained, and second, that pollution (gray), which spikes sharply according to the initial economic peak, is handled completely by natural self-repair.

It is even possible to create something like a steady-state economy, a slightly meandering stream of low but positive activity. When you play with the app, however, you will see that combinations of parameters leading to such favorable circumstances are hard to find, and the solution is highly unstable – wiggle any slider in any direction, and you are quickly back to extinction or boom-and-bust.

Note that in this run high growth is followed by rapid decline and finally zero
growth (brown). The steadiness of the Economy has its price: economic activity is pretty low compared to the once-in-a-lifetime peak at the beginning, and the Resource stock never again reaches its initial wealth due to continual harvesting. The are many more scenarios this simply excellent model can provide, for instance two or three consecutive peaks of activity, increasing or decreasing, followed by die-off (stable solution) or steadiness (unstable solution).

As an apology, I am certainly aware of the irony of porting a model for the simulation of economic decline to the flagship of techno-narcissistic consumerism, klickibunti self-distraction, and perpetual remote controlling of human resources. But, you know, the spirit speaks in many tongues. There is certainly something to gain by playing with the model rather than merely studying formulas or staring at static graphs. Just like the Pythagoreans presumably played with pebbles to gain a feeling for the relation between triangles and squares, you may develop a feeling for the precariousness of stability and, perhaps, understand how inevitable and fierce a destiny is able to fulfill itself.

This said, I would only wish to add that the app is, of course, free, and anyone who wants to learn the background or extend the model is invited to mail me (Hannes Rollin) at initials at sabik dot de. The Seneca cliff App has recently been approved to App.

Sunday, August 28, 2011

The Seneca Effect: why decline is faster than growth


Originally published on "Cassandra's Legacy" on Aug 28 2011

"It would be some consolation for the feebleness of our selves and our works if all things should perish as slowly as they come into being; but as it is, increases are of sluggish growth, but the way to ruin is rapid." Lucius Anneaus Seneca, Letters to Lucilius, n. 91

Don't you stumble, sometimes, into something that seems to make a lot of sense, but you can't say exactly why? For a long time, I had in mind the idea that when things start going bad, they tend to go bad fast. We might call this tendency the "Seneca effect" or the "Seneca cliff," from Lucius Annaeus Seneca who wrote that "increases are of sluggish growth, but the way to ruin is rapid."

Could it be that the Seneca cliff is what we are facing, right now? If that is the case, then we are in trouble. With oil production peaking or set to peak soon, it is hard to think that we are going to see a gentle downward slope of the economy. Rather, we may see a decline so fast that we can only call it "collapse." The symptoms are all there, but how to prove that it is what is really in store for us? It is not enough to quote a Roman philosopher who lived two thousand years ago. We need to understand what factors might lead us to fall much faster than we have been growing so far. For that, we need to make a model and see how the various elements of the economic system may interact with each other to generate collapse.

I have been working on this idea for quite a while and now I think I can make such a model. This is what the rest of this post will be about. We'll see that a Seneca cliff may indeed be part of our future if we keep acting as we have been acting so far (and as we probably will). But let's go into the details.