Wednesday, March 30, 2011

Artificial leaves and old Buicks

Image from "blondygirl"

Back in the early 1980s, in the depth of the first energy crisis, someone in Berkeley invented a way of splitting water into hydrogen and oxygen by using iron oxide and sunlight. That was claimed to be a solution to the energy crisis, it was the object of press releases, and it obtained a lot of coverage in TV.

At that time, I was post-doc in Berkeley with the group that originated the idea and I remember very well how we were bombarded by phone calls from people who wanted to know how they could obtain hydrogen using rusty iron; from "old Buicks" as someone said.

The idea of solving the energy crisis using old Buicks died out in silence in a few months. The efficiency of the process was something like 0.1%, to say nothing of the fact that the oxide became inactive in a few days. You couldn't expect much hydrogen to come out from that old pond in your backyard after you had dumped a wrecked car in it. But, in the hype of press conferences and media report, everyone had conveniently ignored the problem or, at best, mentioned it in passing in terms of "we need more research".

Periodically, the idea of solving the energy crisis by some miracle that involves "artificial photosynthesis," that is water splitting, reappears. Of course, there are many oxides that can split water under sunlight, but the process is usually very inefficient. So, it does make sense to try to improve it and - maybe - a practical process could be developed one day. What doesn't make sense, in my opinion, is to keep producing hyped press reports in the style of the one made in Berkeley long ago.

Something like that - a hyped press report on "artificial leaves" - came out a few days ago from Daniel Nocera at MIT, who described how:

The artificial leaf shows particular promise as an inexpensive source of electricity for homes of the poor in developing countries. Our goal is to make each home its own power station,” he said. “One can envision villages in India and Africa not long from now purchasing an affordable basic power system based on this technology.

Nice, but it sounds a lot like the promise of energy from old Buicks. There is no mention in the report of the efficiency of the process. Talking in terms of duration, Nocera mentions that "an artificial leaf prototype could operate continuously for at least 45 hours without a drop in activity." At least 45 hours??? I mean, even the old iron oxide from Berkeley could last more than that. And a silicon based photovoltaic cell can last for at least 25 years.

Then we read that:

The hydrogen and oxygen gases would be stored in a fuel cell, which uses those two materials to produce electricity, located either on top of the house or beside it.

A fuel cell in a rural village? Do you realize how much a fuel cell  - even of the simplest kind  - costs? Is it clear that, in addition to a fuel cell, the system needs equipment to separate hydrogen from oxygen, a compressor to pump it into something, valves, control electronics, safety precautions and all the rest? And does anyone remember that a fuel cell needs platinum at the electrodes? And that is presented as good idea for a house in a village in Africa or India?

The fact that it should be done "on top of the house or beside it," seems to be taking into account the fact that rural houses in India or Africa, probably, don't have basements. That's a nice touch, maybe; but get real, please, about what the energy return, the EROEI, of the process could be.

Now, that is not meant to disparage Dr. Nocera's "artificial leaf" concept. I am sure it is much more efficient than old Buicks in splitting water and I am perfectly willing to believe that it may be a major breakthrough in terms of what it can do by itself - apart from fantasies such as fuel cells in rural villages.

What I object to is this style of science based on press releases which are only hype and no substance. I understand that scientists are human beings and they like to be in the spotlight once in a while. I understand also that one may need to use these methods in order to get research grants. But, in the long run, this is something that only generated false hopes and disillusion. It is also a way to provide ammunition to those people who have found a lucrative job in disparaging serious science; such as it happens all the time in climate science.

Sunday, March 27, 2011

Tainter's law: where is the physics?

Joseph Tainter's interpretation of the cause of the collapse of civilisations is that social structures generate negative returns when they become too complex; as shown above (fromTainter's 1996 paper at We could call this relationship as "Tainter's law". But what is exactly that generates this behavior? In this post, I'll try to make a simple model that explains the law.

Joseph Tainter has written a fascinating interpretation of the collapse of human civilisations in his book "The Collapse of Complex Societies" (1988) (see also his 1996 paper) Collapse is a common event: it is the stuff history books are made of. The mighty empires of the past; from Sumeria to the Soviet Union, have all collapsed at some point. Yet, we don't seem to be able to understand the reasons why collapse is so common.

In his book, Tainter examines previous studies and lists at least eleven causes (or "concauses") of collapse that have been proposed by historians. Resource depletion, catastrophes, intruders, social conflict, and others. But is there a single cause of collapse? Or are there several? Tainter looks for a single, common root of the problem and finds it in what he calls "the decreasing returns of complexity".

Starting from a well known concept in economic theory, that of diminishing returns, Tainter builds his case on historical examples. It is clear that several societies have continued to build up and maintain complex and expensive structures even in conditions where it was very difficult to find the necessary resources. An example is that of the fortifications protecting the Western Roman Empire, that must have been such a burden that we may consider them to be of the factors that brought down the Empire. And, in general, we do see that societies, including ours, build up hypertrophic and complex bureaucracies which appear totally useless; an increase of complexity that generates only a waste of resources.

The idea of decreasing returns to complexity looks consistent and reasonable. But, why do societies behave in this way? Tainter does not provide a real explanation; on this point, he seems to follow the tradition of historians to describe rather than interpret. But, if you happen to have a more physics-oriented point of view, then describing what happens is not enough. You want to know what are the inner mechanisms that make civilisations evolve towards higher complexity. What is the physics of collapse?

So, let's see if we can build a model of civilisation growth and collapse. The simplest one that I have been able to put together is the following. It is a "toy model, if you like:

The model is based on the conventions of system dynamics. The rectangles indicate stocks of something. You could say that the box on the left contains fossil fuels, whereas the box on the right contains carbon dioxide. The central box contains all the stuff the economy is made of and that is created from the availability of energy from fossil fuels: people, machinery, building, facilities, you name it.

The fossil fuel stock is processed by the economy and eventually transformed into waste, as indicated by the double edged arrows which show the direction of the flux of matter. The single edged arrows indicate how the amounts stored in the stocks affect the flow; that is also influenced by two constants: how fast the economy can extract resources and how fast resources are transformed into waste.

There are a few more points about the model; the first is that the resource stock is assumed to be finite - that is "non renewable". This is an approximation, but it is a good one and not only for our society. Ancient civilizations were based on agriculture, which is supposed to be a renewable resource. But agriculture is not necessarily renewable; it is more often a way to transform fertile land into a desert by mining a non renewable resource: fertile soil.

Finally, note also that the model assumes a feedback relation between resources and the size of the economy. That is, the more resources there are, the faster they are exploited and - also - the bigger the economy, the faster it exploits resources. These assumptions imply a "positive feedback" between resources and the economy; which is a reasonable assumption. A similar relation holds for the waste and the economy.

Now, let's go on and "solve" the model. That is, let's see how the size of the stocks change as time goes by. Here are the results (obtained using the Vensim software for system dynamics)

As you see, the stock of resources gets depleted while the economy grows. At some point, however, the flow from the resource stock has been so much reduced that the economy can't keep growing and it starts declining. In the end, all the stock of resources has been transferred to the "waste" stock.

Note that the model describes a closed system in terms of mass. There is no flux of matter from or to the outside. And, indeed, mass is conserved in the results: the sum of the mass contained in the three stocks is constant. But the system does exchange energy with the surroundings. Burning fossil fuels generates heat, which is dispersed outside as we may assume that all three boxes maintain at the same average temperature.

The main force behind the transformation is energy potential, in this case the chemical potential of fossil fuels. In other words, the left box (resources) has a thermodynamic potential higher than the right box (waste). As we know from the second principle of thermodynamics, the transformation occurs with the creation of entropy. The economy is a grand machine for creating entropy - it could not be anything else.

If you like to use the term "exergy" (the fraction of energy able to do useful work) you can say that the "waste" stock contains much less exergy than the "resources" stock; while the "Economy" stock has an intermediate exergy content. There is no direct system dynamics convention to express stocks in terms of exergy. It could be taken into account in the model, but let's not go into that - let's keep this model as a "toy" one. The important thing is understanding what makes it move.

Now, let's go back to Tainter's interpretation of collapse. What could we take as "complexity" in the model? There is not an explicit parameter describing that but, as a first approximation, the size of an economy determines its complexity. That has been the rule for all known history and we see it happening even today. With the economic crisis, some structures we could once afford - say, mass instruction, public health care - must shrink and disappear. Society loses complexity in times of decline and gains it in times of growth.

So the "bell shaped" curve that describes the cycle of the economy should also describe its complexity. Now, let's walk one further step in quantifying Tainter's intuition. What can be the meaning of "benefits of complexity"? Well, it is clear from what Tainter says that the benefit of complexity have to do with the ability of society to solve problems. In our toy model, the only problem for the economy is to produce as much as possible in terms of resources. So we can define benefits of complexity as proportional to production, that is to the rate of exploitation of the natural resources stock.

Now we can replot Tainter's idea from the data of the model, that is, plot production ("benefits") as a function of the size of the economy ("complexity"). And the result is something that looks very much like Tainter's law! Here it is. (note that in the full plot the curve is a complete loop that goes back to zero at the end of the cycle):

To compare, here is again Tainter's original plot: the two graphs are not identical, but the similarity is evident.

Now, of course what we have been doing here is a "toy model" of the economy. When I present this kind of models at conferences, usually there is someone in the audience who stands up and says, "It is too simple; it is not realistic!". The idea seems to be that I am modelling societies using a "spherical cow model" - a term used to disparage the tendency of physicists to oversimplify their model.

This is a perfectly understandable criticism, but it can be answered noting that more detailed models of the same kind provide similar results. For instance, the "world3" model of "The Limits to Growth" study leads to curves that are very similar in shape to the ones shown here.

But I think that is not the point, you can make models simple or detailed, it depends on what is their purpose. The toy model presented here is not meant to describe how real societies behave. It is meant to be "mind sized", that is able to help us understand how physical factors affect the historical cycle of civilizations. It stresses that civilizations must obey the laws of thermodynamics; just as they must obey the law of gravity.

Some consequences of the model are obvious. It tells us that as long as we base our existence on non-renewable resources, we must eventually run out of them. But it gives us also some non-obvious hint on the path we are going to follow in this cycle. In particular, the model tells us that we will likely keep increasing the size and complexity of our society even with a diminishing flux of resources into the economy. In this sense, it confirms Tainter's intuition, but it tells us something more; that is it extends Tainter's curve beyond the limit of the plot shown in his 1996 paper. It says that after the phase of increasing complexity and reduced returns, the curve will loop back and, eventually, both complexity and production will go to zero as is the economy completes its cycle based on non-renewable resources. Here is the complete plot:

But the main point is that, eventually, Tainter's law derives from thermodynamics. As we know (or should know) thermodynamics is not only a good idea, it is the law!


Tainter's 1996 paper "Complexity, Problem Solving and Sustainable Societies"

A post of mine on Tainter's view of collapse

A paper of mine on modelling resource exploitation

Tuesday, March 22, 2011

The Great Technological Wall

Hadrian's wall in Northern England, as depicted in an illustration for the original edition of Rudyard Kipling's "On the Great Wall" (1906). In this image, the height of the wall is much exaggerated, but it is true that the Roman Empire had built a complex system of fortifications along its borders. However, as the empire's economy declined, it couldn't sustain any more the kind of complexity that was possible at its peak. Complexity has a cost and its returns are not always proportional to it. So it was for the Roman fortifications, that were abandoned in early 5th century A.D., so it may be for some of our infrastructures, such as nuclear energy or manned space exploration . 

In the winter of 406 A.D. (or perhaps 405), the fortifications protecting the Western Roman Empire collapsed. Says Edward Gibbon in his "Decline and fall of the Roman Empire": "This memorable passage of the Suevi, the Vandals, the Alani, and the Burgundians, who never afterwards retreated, may be considered as the fall of the Roman empire in the countries beyond the Alps; and the barriers, which had so long separated the savage and the civilised nations of the earth, were from that fatal moment levelled with the ground" (Chapter XXXI book V)

Starting with Augustus, in early 1st century AD, the Romans had built and garrisoned a vast system of fortifications - that today we improperly call "limes" (*) - meant to protect the empire's borders. From the remnants we can still see today, the Roman defensive system was similar to the Great Wall of China, that existed during the same period. It must have been hugely complex and expensive as it included forts, walls, roads and all the infrastructure needed to sustain a military force.

The fortifications may have improved the effectiveness of the Roman Army in defending the empire. But the walls were also as a burden that locked huge amounts of money and resources. It must have become more and more difficult to sustain the cost of the border defenses as the empire declined. In this sense, Kipling's tale "On the Great Wall" rings true when it tells how difficult it was for the Romans of late 4th century to find resources to garrison Hadrian's wall, in Northern England.

We have here a good illustration of Tainter's principle of the diminishing returns of complexity. With time, not only the capability of the Roman Empire to afford complex structures diminished, it is also likely that the complexity of the structures increased, and with it the need for more and more resources. Eventually, it all came to an end with an especially cold winter in early 5th century, when the iced surfaces of the rivers in Germany let invaders cross the border, unopposed. Gibbon may be too dramatic in his statement of a sudden and complete abandonment of the fortifications but it is true that, with the 5th century, there are no more reports of the imperial borders being guarded by a stable military force.

But the end of the walls was not the end of the empire. Curiously, the demise of the fortifications in early 5th century may have freed resources and generated a minor renaissance for Rome. There followed a period of a few decades during which the Empire managed to regain control over most of its territory. The army was rebuilt and transformed it into a mobile force that turned out to be able to defeat invaders - including Attila the Hun - in every major battle fought in Europe in that period. The empire as a political structure was doomed anyway, but the disappearance of the border fortifications had unlocked the transition that was leading to the new world that we call today "Middle Ages."

The demise of complex structures is a characteristic of declining societies. Even in our world, we are witnessing similar events. With the last space shuttle flights planned for this year, we are seeing  the end of the US manned space program, Apparently, we are abandoning a frontier that we can't defend any longer. Something similar may be happening with the nuclear energy program. Once hailed as a promise of "energy too cheap to meter", we have seen it stalling in the 1980s. Today, events such as the Fukushima disaster may be telling us that we don't have any more, perhaps we never had, the kind of resources needed to manage the enormous complexity of a nuclear energy system. Also here we may need to abandon an old frontier.

Abandoning a frontier, however, does not mean defeat. It means adaptation - it means thriving in different ways. In our case, it means that we need to use systems which are simpler and more effective than those which in earlier times had seemed to be the solutions to out problems. With space exploration, we have discovered that robot probes are both cheaper and more effective than human exploreres. With energy, we may discover that renewables are a simpler and more resilient solution than nuclear. A world based on renewables cannot be the same thing as a world based on fossil fuels or nuclear energy, but it may well be the direction we are heading to, no matter whether we like the idea or not. Wherever we are going, in any case, the transition is unavoidable and we need to understand our limits; otherwise we will crash against them.

(*) The term "Limes" to indicate Roman border fortifications is a modern invention, as shown by Isaac in "The Meaning of the Terms Limes and Limitanei" Benjamin Isaac The Journal of Roman Studies Vol. 78, (1988), pp. 125-147

Sunday, March 20, 2011

Japan, the Hopi and the World Out of Balance

I don't know if this video really comes from the Hopi, but it's incredibly beautiful. Watch it if you have five minutes.

Dreamtime nuclear: Roy Rappaport on the logos of humankind

Roy Rappaport (1926-1997) is perhaps best known for his book "Ritual and Religion in the Making of Humankind" (published in 1999 - image above from the front cover). It was his last work and the one where he concentrated the message of what he had learned in a life of anthropological studies. The book deals mainly with aboriginal rituals, but it is extremely rich of hints and suggestions regarding our modern times. After all, our passage from nomadic hunters-gatherers to commuters of the modern industrial society took only a few centuries, nothing in comparison to the span of existence of our species. 

Somehow, the Fukishima nuclear disaster made me take up again this book and start re-rereading it. I am passing to you just the conclusion, without comments other than noting that everything we do - with nuclear energy or anything else - has an impact on the world. Maybe you'll find in this text some meaning that had escaped to you before - just as it has happened to me. 



From Roy Rappaport's "Ritual and Religion in the Making of Humankind" (1999)

p.  461

All these events took place in the long-past dreamtime, an epoch (which is also a category of existence) that not only preceded the historical past but also continues in parallel with them. Although the totemic beings either departed from the Walbiri territory or vanished into the earth during the dreamtime, they still exist and their powers and actions directly affect contemporary society (Maggitt 1965a: 60). 

So the dreamtime heroes formed the world out of its primordial formlessness (see Meggitt n.d.) largely through rituals and acts of naming and the world's continuity is contingent upon the continued performance of those dreamtime rituals. But, "The people believe that, by performing the appropriate rituals and songs, living men can actually become these beings for a short time and so participate briefily in the dreamtime" (Meggitt 1965a: 60)

In sum, living men, apotheosized briefly as creative beings, are themselves the dreamtime heroes and as such are responsible for the world's creation and persistence. Given humanity's powers to construct and destroy and its position of dominance in ecosystems that it itself can destabilise, its responsibility, as the Walbiri, the Murinbata, and other Australians have long realised, cannot be to itself alone but must be to the world as a whole. If evolution, human and otherwise, is to continue, humanity must think not only about the world, but on behalf of the world of which it has become a very special part and to which, therefore, as Australian aborigines in some sense realise, enormous responsibilities. We may recall here one of Heraclitus' modern interpreters (Kleinknectht, 1967:85): "The particular Logos of Man ... is part of the general Logos ... which achieves awareness in man." The Logos, this is to say, can reach consciousness in the human mind and, so far as we know, only in the human mind. This proposes a view of human nature very different from, and I believe nobler than, Homo economicus, that golem of the economists into which life has been breathed not by the persuasiveness of their theory but by its coerciveness, and from the obsessive focus on reproduction attributed to individuals by evolutionary biologists. Humanity in this view is not only a species among species. It is that part of the world through which the world as a whole can think about itself.


Roy Rappaport as he appears on the back cover of "Ritual and Religion in the making of Humankind"

Thursday, March 17, 2011

Fukushima: the nuclear martingale

The "martingale"(*) is an old scheme for betting on the roulette game. It is simple, seductive, promising, and a recipe for disaster. The Fukushima catastrophe may be the result of the same way of thinking: a nuclear martingale.

It is unbelievable how many people today still think they can  make money out of a roulette game by using the old "double-up" method, also called "martingale". It works like this: you bet on a 50% event, red/black or odd/even, and you double the wager every time you lose. Eventually, when you win, you recoup your losses and make a small profit. Or, at least, this is the theory.

In practice, the martingale method is a recipe for disaster. At best, with it you will not be better off than with playing numbers at random. But it is worse than that: the martingale gives you a good chance to go broke by seeking to double "one last time." Fortunately for gamers, most casinos have betting limits; casino managers want their customers to lose money but not so much that they will go broke and kill themselves.

The martingale strategy is related to what Nassim Taleb has termed "Black Swan", an improbable but catastrophic event. A black swan event is not just a stroke of bad luck. It is something that you create by a series of wrong choices made with the best of intentions. It is the idea of the martingale: a sort of game of chicken played against the laws of probability. In a sense, you try to scare reality by raising the stakes - such as when you double the wager at the roulette game. But whatever small success you obtain in this way, reality is not easily scared and it comes back with a vengeance in the form of black swan: the bigger and the more catastrophic the more you had tried to avoid it.

Martingale-like schemes are typical, for instance, of the financial world. The subprime mortgage crash that started in 2007 is a good example of this strategy as noted by Nassim Taleb. Many financial schemes may be based on similar ideas. And, in these cases, there are no casino managers who stop people from falling into the martingale trap and go broke.

The Fukushima nuclear disaster may be telling us that there is a similar mechanism at play with technology in general. When we design machinery that is dangerous and prone to failure we try to reduce risks by tight regulations, specifics, and centralised control. Of course, these strategies are expensive and therefore are best implemented over large scales. So, we are raising the stakes by building bigger and more expensive systems in order to hedge the risk of failure. In the case of nuclear energy, the result is the concentration of power production in large plants. That strategy seems to work, within limits: on the average, the safety record of the nuclear industry is not bad. But when something goes wrong with a nuclear plant, it tends to go wrong in a big way, such as with Chernobyl and Fukushima.

So, are we protecting ourselves against small failures at the cost of risking large ones? In such case, we would be playing the martingale on a truly gigantic scale. The problem is not specific with nuclear technology. We tend to hedge risks with all kinds of technologies at the cost of risking catastrophes.

Think of coal as an example. We know that burning coal in power plants carries risks. In addition to local pollution, coal may be a major factor in overheating the whole planet because of the greenhouse effect associated with carbon dioxide (CO2) generated by combustion. Against this risk, we are presently planning a major effort in terms of "carbon capture and sequestration" (CCS) - a technology usually referred to as "Clean Coal." The idea of clean coal is that CO2 can be stored underground in geological reservoirs and therefore prevented from reaching the atmosphere.

We may well be playing the martingale with this idea. Suppose that the carbon capture technology will be used on a large scale and that we end up relying on "clean coal" for a major fraction of the worldwide power production. Then, we will have hedged the risk of climate change by raising the stakes: invested money and resources on a specific technology. Likely, we will have reduced local pollution and the amount of CO2 emitted in the atmosphere. But do we know enough about the physics of the sequestration process to guarantee that the stored CO2 will stay there? ? How can we rule out that we'll get that CO2 back in the atmosphere all together and much sooner than expected?

As a black swan, this one borders the unimaginable. Maybe it is an improbable event; sure, but it would be much more improbable if we were just to stop burning coal.

But we just don't seem to be able to reason that way. We tend to go always for the bigger and the more sophisticated technological solution and that carries enormous risks - maybe in terms of unlikely events, but not impossible ones. We are addicted to technology (as noted by George Mobus) and we don't seem to be able to realise that at some point technology starts showing diminishing returns (as Joseph Tainter has noted).

Maybe this is exactly what we are doing with civilisation: playing the martingale. We are hedging small risks by developing technologies, regulations, laws, and controls, all in order to keep society together. But the risk is the improbable, but eventually unavoidable, total collapse. The biggest black swan of all.


(*)  In probability theory, the term "Martingale" refers to processes akin to random walks. Its origin is obscure, but a discussion on its meaning can be found here

Monday, March 14, 2011

We are all Japanese!

 Firebombing of Kobe as shown in the 1988 animated movie "Hotaru no Haka" (Grave of the fireflies) by Isao Takahata. The film is eerily reminding of the present situation in Japan, with the troubles with the tsunami and the Fukushima nuclear plants. It is a beautiful movie, visually stunning, but I don't really suggest to you to watch it, unless you are sure that you do not suffer of depression.

One thing I remember of my first trip to Japan, in the early 1980s, is a conversation with an old Japanese man in Tokyo. We were somewhere on top of a small hill and he was telling me of the time of the war in a mixture of English and Japanese. At some moment, he made an arching gesture, as to encompass the whole city, and he said something like, "it was all destroyed, all the same, minna onaji..."

I had at least some idea of what he meant. I had read Fosco Maraini's "Meeting with Japan" and I had seen pictures of Tokyo after the firebombing in 1945. Later, I went to visit Hiroshima and then Nagasaki. Much later, there came the movie "Grave of the fireflies," telling the story of the firebombing of Kobe. Of course, without having been there, one can't really understand what carpet bombing or atomic bombing must have been. But stories and movies do tell something and just a visit to the Hiroshima Peace Memorial Museum can give you months of nightmares afterwards.

When I was living in Tokyo, in the mid 1980s, I always had the impression of being in a different dimension. It was a sensation of impermanence, something like living in the world of Basho's poems. It was difficult to walk in the city and not to notice that those large avenues crisscrossing the city blocks had been designed with a specific purpose in mind: that of barriers against the spreading of fires. But would those barriers be enough? Every time a small earthquake shook the building of the University of Tokyo, where I was working, it was a little like hearing good old Godzilla stomping its giant feet, just around the corner.

Tokyo has always reminded me of a spaceship or an ocean liner. A huge, sophisticated, complex machine where whatever happens to one, happens to everyone. In the belly of the giant machine, you can't survive alone: if the ship sinks, everyone sinks. In Tokyo, people live in a sort of contrappunto dance where everyone has to move in step with the others - it is the way to live in an immense metropolis where millions of people are moving, working, going to school, talking, eating, bicycling, drinking beers, getting coffee and doing the things people do.

The earthquake and the tsunami of 2011 have been a visual discovery of all what I had been imagining in my worst nightmares. The houses and the fields engulfed by the waves show what happens when you lose the things that keep life livable in a town; including a firm ground to stand on. The explosions of the nuclear plants of Fukushima have been a reminder of how fragile the supply lines are to life in towns.

With the world becoming more and more complex, we need to apply more and more technology to make sure that nothing goes wrong. But, in the end, it is the black swan principle: something must go wrong, sooner or later. And, in our complex world, when something goes wrong, it often does it a spectacular way and then the result is disaster for everybody. We all know that no man is an island. This time, we are all Japanese.

Sunday, March 13, 2011

Ponyo and the tsunami

Have you seen the 2008 movie by  Miyazaki "Ponyo"? Wonderful movie, dreamy and delicate. In it, there is about everything that has shappened this week in Japan: the tsunami, the sea that invades the land, boats swept away, people seeking refuge where they can. It is an illustration of the relationship that the Japanese have with the sea: a bit of fear, a bit of respect and also a bit of love. The whole is embodied by the sea goddess of the movie, Granmamare; a character that echoes the ancient Mediterranean sea goddesses which are more familiar to us, Westerners, Isis o Amphitrite.

The sea doesn't hate us, obviously. But, as for many things on this planet, we cannot pretend to ignore the sea, least of all to dominate it.  Yet, it is a mistake we do all the time; buliding nuclear plants in seismic zones near the sea shore is just one of the many.

Thursday, March 10, 2011

Joseph Tainter: talking about collapse

Joseph Tainter speaks at the conference “Advances in Energy studies” in Barcelona, in October 2010.  Tainter is an outstanding presenter: he speaks slowly, clearly, and in a deep voice. Once you start listening to him, you are hooked; you can't miss a single world of what he says – not even if you don't like it. Indeed, at the end of the talk, we had someone from the back rows shouting, “some more optimism, please!” Understandable, perhaps, but it is said that a pessimist is someone who has had to listen to too many optimists.

At the end of his monumental study titled “Decline and Fall of the Roman Empire” Edward Gibbon discusses the question of whether what happened to the ancient empire could happen in modern times, that in the late 18th century, when Gibbon was writing. His answer is that it could not; new hordes of barbarians couldn't destroy the civilized world because of gunpowder, cannons, modern armies and the like.

It is clear that Gibbon saw the Roman collapse as mainly a military event:  the Romans were overwhelmed by one wave of Barbarians after the other. But, like many other historians before him, Gibbon chronicled events without normally interpreting them in the sense we give today to the term - that is finding social, economic or political reasons to explain what happened.

Gibbon, living in the thriving and expanding world of 18th century Britain, just couldn't see that there was much more in the Roman collapse than a simple military problem. It would take time for historians to see the collapse of the ancient world as something related to our own destiny. With collapse impending, or perhaps already started, we can start seeing that the Roman times are a foggy mirror of our times.

Joseph Tainter is the historian who, today, has grasped this relation better than anyone in the past. He is well known for his book “The Collapse of complex societies” (1988) and for the articles he has written on this subject. Here, I am summarizing the talk that Tainter gave at the "Advances in Energy studies”  conference in Barcelona, in October 2010. It was not the first time that I heard him speak and I had read his book (and more than once!). But every time you hear Tainter speak, you have this sensation that he is going deeper and deeper into the problem; that he can present more and more evidence of the relevance of the past for the present. History does not necessarily repeats itself, but when facing similar challenges, people of all ages will tend to react in the same way. That's the relevance that history has for us today and, in particular, the history of the decline and fall of the Roman Empire.

Tainter's main point is related to complexity. He does not exactly define the term, but it is clear from the context that he means all the economic, social, bureaucratic, and military structures that societies create. Complexity is the characteristics of what we call “civilization”. Tainter dismisses the view – that he calls the “progressivist” viewpoint – that complexity is the automatic result of the availability of resources; mainly energy. Correctly, he says that complexity creates resources just as resources create complexity. Tainter doesn't use the terminology of system dynamics, but if we see things within that framework, then we can say that complexity and resources are in a feedback relationship with each other. Resources allow the creation of more complex societal structures and these structures help exploiting resources faster and more efficiently.

In earlier works, such as in his 1988 book, Tainter dismissed also the idea that collapse, intended as a rapid reduction of complexity in a society, could be caused by resource depletion. He would define it as related only to the diminishing returns of progressively increasing complexity. In his talk in Barcelona, however, I think that I can interpret his view in terms closer to the “depletionist” viewpoint. In this sense, Tainter's point is that there is a strong relationship between resources and complexity. It is clear that complexity cannot exist without resources - not for a long time, at least. But the relationship is far from being linear: with resources diminishing, complexity does not decrease – on the contrary it keeps increasing. It is the result of the benefits that complexity gives: resource depletion can be counteracted by increasing complexity, but only up to a certain point and with ever-reducing returns. At some moment, returns become negative, society cannot support any longer its complex infrastructures and the result is collapse.

In his talk in Barcelona, Tainter gave the example of the Roman Empire during the 3rd century A.D. At that time, the Empire faced a serious military crisis: invasions of foreign peoples and internal civil wars. The crisis was solved by Diocletian by doubling the size of the army, increasing taxes and enlarging bureaucracy; overall it was a considerable increase in complexity. Transforming the Roman Empire into a sort of an early version of the Soviet Union was a solution – of a kind – that retarded collapse of a couple of centuries but that, in a certain way, made it unavoidable. The Roman Empire could not afford such a large army and, eventually, it destroyed itself in the attempt of maintaining it. Not unlike the modern Soviet Union.

According to Tainter, we are doing more or less the same. Perhaps our society is not so heavily military oriented as the Roman one, but we are reacting to the crisis much in the same way. Despite all the talk of “saving” or “conserving” resources, it is clear that our society is not doing anything like that. We strive, certainly, towards more efficiency, but the resources that are saved in some areas of the economy are used in some other areas. Being more efficient in extracting resources means that we are running out of resources faster. Being more efficient in using resources means that we are able to create more complex structures that use those resources faster. It is the so called “Jevons paradox” in its strongest form.

The Romans could never fully understand what was befalling on them and they went down kicking and screaming, always thinking that a few more legions could solve all the problems. That was also because they had no structures – research centers, universities or the like – that could alert them. We do have such structures and we have had good warnings since the time when “The Limits to Growth” was published, in 1972. But we also have structures built expressly to demonize and destroy those who bring warnings, we call them “media spin" or "media based consensus building". These structures have been efficiently used to play down the warnings we had from “The Limits to Growth” and are being used now to play down the warning about global warming that we are received from climate scientists. So, having computers is not a great advantage for us over the Romans. It seems that we are going their way.

You can read an excellent summary of Tainter's book "The Collapse of Complex Societies" written by Anatoli Karlin. Some (long) ruminations of mine about the fate of the Roman Empire can be found in this post on the oil drum, titled "peak civilization". You can find Tainter's slides for his 2010 Barcelona presentation at this link.

Monday, March 7, 2011

What punctured the North-African balloon? Crude oil and social unrest

Many people have suggested that the ongoing unrest in North African countries has been generated by high oil prices or problems with oil availability. It is always difficult to be certain about what drives events such as revolutions and civil wars. However, physical models of complex social systems can help us understand what are the driving forces of the events that we see. 

One of the lectures of my class in materials science involves showing to the students an inflated balloon. I puncture it with an needle and it explodes. Then I ask to the students to explain to me exactly what has happened. Why did the balloon explode and not just deflate gradually?

It is not an easy question and, usually, my students cannot answer it. We learn as children that some objects break more easily than others. It is after a good number of failures that we learn how to handle glasses and china. And, yes, we do learn that puncturing an inflated balloon with a needle makes it explode. It looks normal to us because we have seen it happening many times. But it is difficult to explain exactly why.

Human societies, it seems, have some elements in common with inflated balloons. A society is not as simple as a balloon, of course, but it can easily explode in revolutions, collapse, breakdowns, civil wars and all sort of rapid and unpredictable changes. Societies, it seems, are fragile, at least in terms of the stability of their governments. This behavior looks normal to us because we have seen it happening many times. But, just as for balloons, it is difficult to explain exactly why societies "explode."

Of course, the difficulty of the problem has not prevented historians from proposing various causes for past collapses and revolutions in terms of economic, political, and social factors. Recently, crude oil has become popular as the cause of dramatic social changes. For instance, the collapse of the Soviet Union has been related to the local peaking of oil production (see this post of mine on The Oil Drum). Could crude oil be the "needle" that has been puncturing North African countries as well?

But how exactly is peak oil related to collapse? Why doesn't society simply adapt to the new conditions? I think we can gain some insight on these points if we consider human societies as complex systems which obey the laws of physics.

There are some common physical elements in the behavior of balloons, human societies and many other systems. One is that these systems accumulate energy. A balloon accumulates energy as pressurized gas, a society accumulates energy in forms that we tend to call "capital" (human capital, monetary capital, industrial capital, etc.). Both inflated balloons and societies are systems defined as "out of thermodynamic equilibrium" because of this accumulated energy.

The second principle of thermodynamics says that system will try to find the fastest possible way to reach equilibrium, that is the condition of maximum entropy. That means dispersing the accumulated energy to the largest possible number of states. The system will do that by following the available pathway that leads faster to that condition.

Thermodynamics doesn't say that a pathway (fast or slow) to equilibrium must necessarily exist. In the case of an inflated balloon, as long as the balloon walls are intact, there is no such pathway and the balloon stays inflated. But, if we puncture the balloon, we create a fast route to entropy increase. In the right conditions, that is, if the accumulated energy is sufficiently large, the crack created by the needle tip generates a rapidly expanding fracture. The balloon explodes.

Human societies are much more complicated than a balloon but, in the end they tend to reach equilibrium by dispersing the accumulated energy - that is, reaching a condition of maximum entropy. That means transforming the accumulated energy into what we call "waste" or "pollution". The dispersal process can take many different routes: a society is a tangle of feedbacks; with some stabilizing the system while others destabilizing it. Societies also grow new structures and new stocks of energy as they exploit natural resources. Then, when the stocks of non renewable energy are gradually exhausted, the rate of energy processing slows down - that's something we sometimes call "The Hubbert cycle." The fact that production shows a peak ("Hubbert's peak") is typical of crude oil, but it is a normal feature of dynamic systems of this kind. The cycle of a society often follows a "bell shaped" curve (e.g. for the Roman Empire)

Sometimes, the process of energy dispersal is smooth, but sometimes it is not smooth at all. Societies seem to be easily subjected to rapid and sudden changes as the system finds new pathways to disperse energy. In some cases, a growing society gets rid of a stumbling block to energy dispersal. This could be a good model for events such as the French Revolution that found such a stumbling block in the aristocrats of the time. In other cases, when a society is declining or reaching a peak, the problem may be that some structures built in order to manage large fluxes of energy become useless and must disappear. That may have been the case of the Red Army and of the Communist Party in the Soviet Union. In all cases, the social system is blocked in an out of equilibrium condition because of the lack of a path to release the stored energy. Such a path may be created, however, by positive feedbacks generated by apparently minor events, for instance an increase in oil prices. Then, when the pathway appears, the transition may be abrupt: it is what we call revolution or collapse.

How about Northern African countries? In this case, we don't have yet a clear picture yet of what is happening, especially for the case of Libya. But we know that the uprising in Egypt arrived shortly after that the curve of internal consumption crossing the one of national production. Egypt "exploded" when it became a net importer of crude oil (see e.g. this paper by Gail Tverberg). Tunisia went along the same path with consumption surpassing production around 2001. In the new condition of oil scarcity, these societies needed to get rid of energy expensive structures in the form of static governments that had been around for decades. That, of course, was not easy to do and it needed a trigger; something that released the accumulated pressure. Not unlike a punctured balloon.    

We should always be careful about simple explanations for complex events. More than all, we should be wary of falling in the trap of seeing a simple chain of cause and effects in complex systems. Oil prices are not a "cause" of the unrest - just a trigger for something that needed to happened for other reasons.

But, even with these caveats, we know that oil - as our main source of energy - plays a role in the recent unrest in North Africa and will continue to do so in the future -. and not just in North Africa.

To know more about energy dispersal and entropy in out of equilibrium systems, you may give a look the papers by Arto Annila and coworkers at the University of Helsinki. Not the kind of stuff you read to relax in the evening, but - if you can manage to digest it, at least in part - it can answer a lot of questions you have always been wondering about.

Friday, March 4, 2011

How to drive your elephant: dealing with complex problems

One thing that I plan to do with this blog is to repost some stories that I posted on "The Oil Drum." Here is one that I think is especially suitable for "Cassandra". It deals with Elephants and was published on TOD in April 2010. This version is slightly modified and shortened with respect to the original one.
Something that has always intrigued me about elephants is how the people who drive them manage to control theme without a harness. There have to be ways, since it can be done, but it cannot be simple. So elephant driving may be seen as as a metaphor for controlling complex systems. What you'll find below is a talk that I gave on this subject at a meeting in Souther Italy - in Martina Franca. It is not a transcription, but a version written from memory that tries to maintain the style and the sense of what I said.

Thank you ladies and gentlemen for being here today. I see that most of you are entrepreneurs or company managers and so it is a real pleasure to have a chance to speak to you. We, the academics, can only speak about what is to be done, but you are the people who can get things done. For this reason, I thought that I could tell you something that might be useful to you. So, I'll be speaking about elephants.

Now, of course this is a joke. This talk will not be about elephants; not as the main subject, at least. What I know about driving elephants comes mostly from a story by Rudyard Kipling that I read long ago and that, of course, is not enough for me to qualify as an expert on elephants. What I have in mind, instead, is to tell you something about control theory. But, since we were supposed to have parallel sessions today, if I had mentioned control theory in the title to my talk I was afraid that nobody would have appeared to listen to it. So, I mentioned elephants, instead. From this, at least, you have learned that even academics may know something about marketing.

The elephant is a nice metaphor for what I would like to tell you today. You see, you can't fit a harness to an elephant, at least not of the same kind that is used for horses. Then, how do the people who ride elephants tell the beast to start, stop, where to go and the like? The way it is done, I understand, is by means of such things as vocal orders, pressure with one's legs and also by a big pointed stick that is used to prick the elephant's head. I don't think the elephant is very happy about being pricked in that way; actually, there is probably a good deal of cruelty involved. But we'll be using elephant driving just as a metaphor for controlling complex systems, so let me just say that it seems to work: you can control an elephant by very small external influences. This is the core of control theory: you want to be able to control large and complex systems doing the smallest possible amount of work.

Control theory is a fascinating subject, often used for controlling such things as planes, ships, and other kinds of machinery. It might also be used for elephants, but there is a difference. With a car or a truck, you turn the steering wheel so much and the wheels turn of so many degrees. You don't need to make a big effort with the wheel to turn a large truck, but the point is that the result is proportional to the effort. On the contrary, the elephant may not like to go the way you would like it to go and may react in ways that are not at all proportional to what the driver does. That must make things much more difficult. Now, there is a whole class of systems, we may call them "complex systems," which are difficult to control because they react in ways that are not simply proportional to the intensity of an external influence. That means economic and social systems, for instance and - perhaps - also elephants. For what we are discussing here, we might consider that these systems are dominated by internal feedback effects.

The behavior of complex systems is often difficult to predict, but that doesn't mean it is impossible and there is a whole branch of control theory that deals with this problem. Sometimes, controlling complex system is defined as involving "cybernetics," a term that was proposed by Norbert Wiener in 1948. There are several definitions of cybernetics today, but Wiener was very interested in feedback dominated systems; that is, complex systems. That seems to be still the main aim of cybernetics, although nowadays the term has a bit faded from public consciousness. The term "cybernetics," anyway, comes from a Greek word which means "rudder" and that shows what Wiener had in mind when he coined it. A rudder is used to steer a ship and that may be a better term to use; rather than "control". Especially when we think of very large complex systems such as the economy or the state, "control" sounds like what the Soviet planners were trying to do and that, as you know, turned out to be not so successful. So, you don't want to control every detail of the system; you don't want to tell the elephant how exactly to move its legs. You just want to steer the elephant. Then, the elephant knows how to walk.

We don't have a general theory that tells us how to steer a complex system (nor an elephant), but we do have good models that allow us to understand how a complex system behaves. And if you understand how the system behaves, then you can think of what to do to make it go in a certain direction. One of the commonly used methods to describe complex systems is called "system dynamics." It was developed mainly by Jay Wright Forrester in the 1950s and 1960s. You may not have heard of Forrester, but the study known as “The Limits to Growth” was performed using the methods that he had developed. You may have read that “The Limits to Growth” is a set of wrong predictions, a flawed study, the work of a group of eccentric (and perhaps slightly feebleminded) academics who had thought that the sky was falling. That is not true – it is mostly propaganda and our tendency of believing what we like to believe. "The Limits to Growth" (1972) and an earlier work by Forrester himself, titled "World Dynamics" (1971), were pioneering works that showed that it is possible to understand the behavior of large and complex systems such as the whole world's economy and, within limits, predict their evolution.

Modifying the behavior of these large and complex systems turned out to be much more difficult. The authors of "The Limits to Growth" searched for ways to avoid the collapse that was predicted by their models. They found that it was possible, but it needed rather drastic measures, such as curbing the world's use of mineral resources and stabilizing the world's population. Of course, that is not something easy to do and - in addition - not something that people like being told. Not only the suggestion was refused, but the authors were accused of being part of a conspiracy to take over the world, to be planning to exterminate most of humankind, and similar niceties. We are seeing a similar reaction nowadays with the global warming issue which, by the way, has to do with a large and complex system; that of the Earth's climate. So, it is very difficult to control very large complex systems, if nothing else because these systems tend to resist change and sometimes react violently against those who try to control them (maybe elephants do the same when they are pricked on the head).

But, if you reduce a bit your ambitions; that is, if you don't try to save the world, just a little bit of it, then system dynamics can give you precious advice. So, what I'd like to tell you now is about an idea that Jay Forrester had; that of the existence of "critical points" (or leverage points) in complex systems. Points you may act on to steer the system without having to do a large effort. A little like pressuring or pricking the elephant in some specific points of the head. You can have a very strong effect on the system by a very small external influence.

This idea of Forrester can be found in his papers, especially those dealing with "urban dynamics," where he reports that most of the commonly implemented policies in urban planning generate results that are opposite to those intended by the policymakers. But Forrester's ideas were also described and discussed in a paper that Donella Meadows wrote in 1999 with the title "Leverage Points, places to intervene in a system" . It is a rather famous paper, also very interesting. I strongly suggest to you to read it when you have a moment. But let me describe its main points for you.

Donella Meadows says that it is easy for most people to identify critical points (or leverage points) in a system; points which strongly affect how the system behaves. If you think about that for thirty seconds, I am sure that you can think of several of these points in your life, in your career, in your company. Elements that either push you onwards or prevent you to do so. Say, your boss stops you from doing what you would want to do, or maybe your husband or your wife are not doing what you would like them to do; that kind of things.

And here is the interesting point. Sure; people are good about identifying critical points; but very bad about doing something about them. What Forrester had noticed is that people tended to act on these points; but pulling the levers in the wrong direction. They would mostly act on the critical points in such a way to worsen the problems, rather than easing them. That sounds strange at first; but let me give you a few examples and I think you'll agree with me (and with Forrester) that people do tend to pull levers in the wrong directions.

You are all involved in managing companies, so I'll try to give you examples that have to do with industry. Let me start with an old story, that of the whaling industry in 19th century (this talk seems to be concerned a lot with big mammals!). In 19th century, people used whaling technologies that may appear to us a bit primitive: sailing ships and hand-held harpoons. Nevertheless, they were efficient enough that whales were captured faster than they could reproduce, at least for some kind of whales that were relatively easy to capture.

By mid 19th century, there was a depletion problem: too many whalers and not enough whales. The result was something similar to the reaction that we have today with of crude oil depletion. You heard the cry: "drill, baby, drill." It means drill more, drill deeper, drill in places where no one had drilled before. In the case of whaling, we could say that the reaction was something like: “hunt, baby, hunt". Get more whaling ships, better equipped, going faster, and go chasing as many whales as you can. But that worsened the problem. The more whales were killed, the less there were in the ocean. By the 1880s, whalers had run out of whales, at least of the kind that was hunted in that period. So, the whole whaling industry collapsed. Whalers should have agreed to hunt fewer whales, not more. They should have placed quotas on the number of whales that could be captured. That would have given time to whales to reproduce and give the whaling industry a chance to survive. That was the right way to pull the lever; but; as Jay Forrester and Donella Meadows tell us, that is very difficult.

This kind of behavior has to do with the gut reaction of industry managers when they see sales going down. Their reaction is often the same: lower prices in order to maintain one's market share. That may involve being more efficient, lowering the quality of the product, laying off "unnecessary staff" and, in general, cutting corners wherever possible. That may work in the short run, if the problem is only temporary. Then, when sales pick up again, those people who have maintained - or increased - their market share, will emerge as the winners. But if the problem is structural, as it was in the case of whaling, then it is a suicidal strategy. Everyone tries to keep a constant share of a market that keeps shrinking and the end result can only be collapse.

Let me make a modern example: years ago I stayed at a seaside hotel in Italy. They have me in their mailing list and they keep sending me leaflets with their special offers. I notice that this hotel is becoming cheaper and cheaper as time goes by. If they keep that trend, at some moment it will be cheaper to stay there rather than eating at home. How long can they go on reducing prices without going out of business, I can't say, but surely it cannot be forever. As I said before, lowering prices is a suicidal strategy in the long run.

Now, let's examine the problem with Forrester's ideas in mind - the critical points of the system. Clearly, the manager of that hotel has correctly identified a critical point: many people can't afford any more long vacations. So, suppose you are in charge of the hotel, what would you do? I think there is something here in the idea of doing exactly the opposite of what that manager is doing; that is raise prices. It looks a bad idea at first, but think about that for a moment. If you can improve service, then you can gain a share of the high-end of the market; and that fraction of the market will probably survive the crisis.

In the end, what Forrester says is to be creative. Don't just fight to stay where you are. Find new roads; new ways of doing things. So, stop thinking about tourists. Think instead of transforming your hotel into a school where people can be re-trained for new jobs in a changing economy. Train people, say, in installing solar panels. That is something that will be needed in the future. It is just the first idea that comes to my mind - but I am sure you understand what I mean. You are all creative people and - if you were hotel managers - you would surely think of other possibilities.

But, unfortunately, creative people seem to be just what we are missing. Everywhere, people are fighting as hard as they can not to change things, but to keep things as they are. And, as I said, that is a losing proposition. Think of the automotive industry. They have a lot more clout than the hotel industry and they managed to convince the government to subsidize their sales with taxpayers' money; it is what they call the "cash for clunkers" scheme. But our problem is not that we aren't making enough cars - we are making too many of them! Here in Italy, the cash for clunkers scheme has ended in December of last year and car sales have hit rock bottom. So, the cash for clunkers scheme wasn't a good idea, surely not in the long run. Car makers should think in different ways and move to something else. Windmills or bicycles, I don't know, but surely we can't afford any more to make so many cars.

So, I gave to you just a few examples of Forrester's and Donella Meadows's ideas about critical points. The concept of critical points is a very powerful mental tool and not just for the kind of problems I described. It may work even for your everyday life - even if you are not an elephant driver. You probably are engaged in such things as finding money, finding a job, getting a degree. Maybe you have problems with your relation with your children, your spouse, your boss, your coworkers. Sometimes these problems seem to be enormously difficult. Now, consider that one reason might be that you are pushing in the wrong direction.

I am not saying that changing that direction will work every time, but you may at least consider it. It is, in the end, about being a bit creative. Try it.

I wish to thank Costellazione Apulia for giving me the possibility of giving this talk in a nice and friendly environment at the meeting "Raccontami una Storia" in Martina Franca, Italy, on March 19th 2010.

The paper by Donella Meadows about leverage points is at (
The story by Rudyard Kipling that I have mentioned is titled "Toomai of the elephants" and you can find it, for instance, at
As I mentioned whales in addition to elephants, you can find a paper of mine on the subject at
About the negative reaction against "The Limits to Growth" you can give a look to a paper of mine titled "Cassandra's curse: how "the limits to growth was demonized" at

Wednesday, March 2, 2011

The time machine of the 1960s

Last year, I gave a talk in a meeting in Parma, Italy. I had prepared a presentation on crude oil but, when I arrived there, I saw that my audience was mainly composed of young students, probably not very interested in statistics about oil. So, I had to change subject and tone and the idea of speaking about a "Time Machine" came to my mind. Here is the result; it is not a transcription but a version written from memory where I try to maintain the style of an oral presentation.

Ladies and gentlemen, thanks to all of you for being here. From what I can see, many of you are university students and some of you look so young that you have to be in high school. It is nice for me to have such an audience, sure, but you are also a problem. You see, I had come here with my presentation on crude oil. I had data on reserves, production trends, that kind of things. But, now that I see you, I think you won't be interested so much in that, especially in a meeting which has to do with people's right to food. You are interested in the future; that's the reason why you came here. And in my opinion, crude oil belongs to the past.

One thing that I should tell you, anyway, is that we still have oil to extract and burn. Oil is not going to run out tomorrow and not even in a year or ten years. But things are changing fast and oil is not any more so abundant as it used to be. We are moving towards a world where there will be less and less oil to burn - and that is the future you'll see; the future in which you'll live.

So, I had with me this presentation nicely prepared in Power Point, but I won't show it to you. I think that Power Point is an evil thing; made by Sauron or by someone like him - once you have spent a lot of time preparing your presentation, then it is hard to change it - to change tone and subject. But I know that my presentation won't be so interesting for you and so I'll leave my slides where they are and I will talk to you about a completely different subject. I'll tell you about time travel; actually how time travel was invented in the 1960s. Well, not exactly "time travel," but something like it. But let me explain.

First of all, let me ask you to imagine a future not too remote from now. Think of the time when you'll start "shopping," so to say, for a good subject to do your PhD work on. For many of you it will be in a few years from now; perhaps some of you are doing that right now. So, let's imagine that you go to see professor Deriu, our host today, the organizer of this conference, and he tells you, "well, you know, we have just developed a time machine here in our lab at the University of Parma. It can take you to the future of a hundred years from now. Would you like to do your PhD work on this?"

How about that? You are young and you are all interested in the future. And, a time machine that takes you to the future, wow! that would be something!

Of course, no matter how good a researcher is professor Deriu, I think he hasn't arrived yet to developing a time machine; one that takes you to the future and back. But maybe it could be built. I don't know if there are physical reasons preventing it to exist; but I know that - if it were ever built - it could only take you to "a" future, not to "the" future. The future, after all, is in our hands; it depends on what we do. So, if a time machine takes you to the year 2110, then you come back and you do something based on what you learned in your trip; then the future must change. So, when you go back to 2110, what you see is completely different. That is, after all, the theme of the movies of the series "Back to the Future," but not just of that movie. Plenty of science fiction has been written on this theme: you go to the future, see how it is, then you come back and you do something to change it. The future can never be exactly predicted, it is not fixed.

Now, as I said, a time machine doesn't exist today; maybe it will never exist. But something like the story I have been asking you to imagine took place in the late 1960s - many of you weren't even born at that time. It happened at the Massachussets Institute of Technology, the MIT, in Boston, where someone named Jay Forrester was working.

I think you'll like to hear a little about Jay Forrester. He was born - if I remember correctly - in 1918. He has traveled quite a stretch in time! And, last time I wrote to him, he answered to me via email - though he is in his 90s, his mind is still sharp. We are all time travelers, after all, and if you are lucky you travel in comfort - not forever though, but that's another problem. Anyway, Jay Forrester has been a pioneer of computer science: he led a team who developed a new computer memory that became the standard for computers in the 1950s and 1960s. At that time there was no such thing as a "personal computer." There were those big computers; you know, big cabinets occupying several rooms and with technicians in white coats running around. And these big computers were much less powerful than your laptop, today. Things change as you travel in time.

Anyway, Forrester was interested in many things; one was the future. Of course, he didn't have a real time machine. But he had this idea that he could use the computers he had built as something that could "see" the future, although not really predicting it - that, as I said, is not possible. His idea was to study the future. It is something different. In science, when you study something, you do it as a function of the parameters of the system. Say, when you study a chemical reaction, you do such things as changing concentrations, type of reagents, that kind of changes. And then you see what happens. So, when you study the future, you change some of the parameters and you see what happens. You play the game "what would happen if..." And that is what Forrester had developed: a model of the world that could be run in the memory of a computer and generate different futures depending on the parameters in input. Each one is what you call a "scenario." In a way, it is a time machine, although it is a virtual one. But it can describe a possible future, a destination you could find yourselves traveling to .

So, imagine you were a PhD student working in Forrester's lab in the 1960s. I guess the atmosphere must have been very exciting. They had these new computers, very powerful for the time, and they were using them to study the future. It would have been great to be there and to work on these models.

The story, at this point, has to do with someone named Aurelio Peccei - you probably never heard of him as well. He was Italian and he was at the head of a group of people who referred to themselves as the "Club of Rome." They had started with the idea that they wanted to do something to help the poor in the world. But they soon discovered that it was not an easy task - of course we all know it is not. One basic question was, "do we have enough resources for everybody on this planetr?" In other words, what are the limits to the resources on earth? Obviously, that was a difficult question to answer. So, what happened was that Peccei met Forrester in Italy, at a meeting on the shores of Lake Como. That was in the late 1960s. Peccei was impressed by Forrester and probably Forrester was impressed by Peccei. They met again in Switzerland, later on, and in the end they decided that the model that Forrester was developing was just what was needed to solve the question that the Club of Rome was asking.

So, one of Forrester's students took up the task of making a big model of the whole world for the Club of Rome. His name was Dennis Meadows. At that time he wasn't a student any more, he was 28 years old, but he was young anyway. And so the research called "The Limits to Growth" was started. Dennis Meadows collected a group of young people and they started modeling the whole world for a future that spanned more than 100 years, up to the end of the 21st century. I am sure that they were absolutely thrilled by the challenge. I am sure that all of you would be thrilled. It was an incredible chance: use the computer as if it were a time machine and explore the future of the world! In the past few years, I have had the chance of meeting some of the people who worked on that project in person. Now, of course, they are in their 60s or 70s; but they maintain a lot of enthusiasm for these studies. The had the chance to see how their scenarios have fared over almost 40 years of comparison with the real world. As I said, we are all time travelers.

So, what did they find with their virtual time machine? The results are described in a book titled "The Limits of Growth" which was published in 1972, almost 40 years ago. Today, if you heard about that study, you probably heard that it was all wrong. That it was a flawed study based on wrong data and that it had predicted that the world should have ended - maybe - in the 1990s and that, of course, didn't happen. Or, if you never heard about it, you may wonder why - if it was so new and important.

Here, you have to be careful. You probably know the old say about computers: "garbage in, garbage out". It is true and it is a good warning. As I said before, if you are using the computer as a time machine, you must be aware of the limitations of a time machine. If you expect the computer to be able to predict the future, you'll be sorely disappointed. The future depends on what we do and if we decide to do one thing rather than another, then the future will change. That's the basic idea of what people call "scenario planning". You don't try to predict what the future will be. You try to figure out what it may be and act in consequence.

That, believe me, is a lot. You read newspapers and the feeling is that nothing of what happens could be imagined just the previous day - let alone predicted years before. You get the impression that we live in a world where politicians surge every day to meet some challenge that was utterly unexpected, and they gain much press coverage in the process. But it is not like this. Computers give you a tremendously powerful tool to manage the future. Not tomorrow's future, of course. If I could predict what will happen tomorrow, and I could predict it exactly, well, I would be somewhere else, of course. But in the past 10 years or so I have been working with this kind of models and I am impressed at the insight that they can give to you. In the past few years, nothing of what happened has really surprised me - it is almost scary. Of course, I can't predict the exact year when something will happen, or details of what is going to happen, but I can have a general idea of what is in store for us.

As I said, it is a little scary to have tools that can give you some idea of the future. That is because the future is not always bright - of course. And that brings us back to "The Limits to Growth," the study made in 1972. The study was not "wrong" as some people said later on - the problem was that the future it saw for humankind was not bright at all. And people didn't like that. So, rather than thinking "how can I make the future brighter?" they decided that the study was wrong. It happens all the time - it is a tough life for those who chose this job: exploring the future.

Anyway, the authors of "The Limits to Growth" did a good job in exploring many possibilities for the world's future. But most of their scenarios had a "robust" feature, something that didn't change much as a function in changes of the parameters in input or of the model itself. That was collapse of the world economy. And if the economy collapses, a lot of things must collapse with it, including the human population. There was a scenario in the study that was called "base case", or "standard run" - the one which had as parameters data which were the best available and that assumed that the world - meaning the way people behave - wouldn't change too much over time. Well, this scenario produced the start of the collapse of the economy for around 2010 -2020.

Now, I think you start understanding where I am heading to. In practice, I am arriving to the same concepts that I could have shown to you from my power point presentation on crude oil. You see, collapse is the result of a number of things happening right now; in front of your eyes. Less and less crude oil; and that forces people to pay more for it. And, eventually, we'll arrive to a point where we can't afford it any more. And that is not just a problem with crude oil - it happens with all mineral resources. If minerals are what keeps the world's economy running, then you'll see it collapse. And there is another resource which is gradually running out; it is the capability of the atmosphere to absorb the products of combustion of oil and of fossil fuels. As you know, the consequence is we are gradually heating the whole planet - that's no good for the economy, either. And for us all; too. 

So, this is what we are seeing around us. Things are starting to collapse - maybe not exactly collapsing - but surely there are all those ominous creaks that you hear when a structure is near collapse. The economy, the prices, all those things that happen. I could give you more data; but I think the general picture should be clear to you. We have been growing at the expense of the natural capital of our planet and now we are being asked to repay it, with the interests. All that was known from a long time ago, with that 1972 study "The Limits to Growth".

Now, there is one thing I have to tell you. It is that the people of my generation - those who are in their 50s or older - they are those who are now managing things in the world and they have used up a lot of what there was of oil and of all the rest. And they are planning to use up everything that is left. That means that when you'll be my age there won't be much left for you to use.

Maybe I should apologize to you for what my generation has been doing. But the previous generations did the same and yours will try to do the same - with what little there will be left. So, let's take that as a fact of life. People just don't know how manage resources on this planet and they tend to shift the burden of their mistakes on the future generations. It is the game they call the musical chairs and - in your case - I am afraid that you may be the ones left standing at the end.

So, you'll probably have a rough trip to the future; as I guess you already knew. What I can tell you is that you all have a good time machine inside you head - as long as you use it. You have to use it because plenty of people, out there, are trying to cheat on you; telling you that there is nothing to worry about. But you don't really need complicated computer models to understand what's happening and in which direction we are going. Just use your brain.  It will be a difficult road, but if you know where you are going, you can make it. I wish you a nice trip! 

I wish to thank prof. Marco Deriu of the University of Parma for having given to me a chance to speak at the meeting "Il Clima della Democrazia" in October 2010

Cassandra's legacy

Welcome to the new blog "Cassandra's legacy". Development is in progress

This is a blog by Ugo Bardi; I am interested in peak oil, resource depletion, climate change and - in general - on the evolution of complex systems, such as human societies. This blog is about that - its title comes from the Cassandra of the Iliad, the prophetess who tried, in vain, to warn her fellow Trojan citizens about the dangers ahead. They didn't listen, as we know, but she was right. Today, we still tend to ignore warnings and to use the term "Cassandra" as an offence- it is the Cassandra legacy.


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)