The law of conservation of legends

The classic urban legend of alligators living in New York's sewers. An example of the incredible staying power of legends (image from Wikipedia)

You know, I was trained in "hard" sciences; physics and chemistry. I learned that some physical laws are deeply entwined with the fabric of the universe. That you can't win against the relentless growth of entropy, that mass and energy are equivalent and conserved, that gravity always pulls matter together, and so on.

Now that I am learning a little more about the so called "soft sciences", such as communication, I am surprised to discover that there are some hard laws there too. Something that never ceases to amaze me is the incredible persisting power of legends. Really, it seems that it is more of a hard law than the second law of thermodynamics which, after all, is statistics in nature. The law of persisting legends has no statistical justification: it just exists.

Let me tell you about something that happened to me just half a hour ago. I am presently writing a paper on the effect of depletion on mineral extraction and for doing that I have to consult a number of rather ponderous tomes. So, I opened up a paper written in 2010 by.... well.... let me not write the name of the author here. Let me just tell you that it is written by a German geologist and it is dedicated to the classification of mineral resources. It is nothing like your average "publish or perish" paper; quickly assembled to improve one's h-index on the fly. No, it is a carefully written, extensive, encyclopedic tome of 420 pages!

So, I donwload this massive paper, start reading it and, at page 7, at the very start of the text, I find:

The widely known report "Limits of Growth" by the “Club of Rome" predicted in 1972 that by the year 2000 many deposits will be exhausted and many metals will no longer be available even at a high price level. The pessimistic and very constricted view of this group of persons has proved to be wrong....

All right; I told myself: don't forget that you have only one liver. I counted up to ten; then I counted up to ten again, then I regained a certain level of relaxation and consciousness. It was no small feat for someone - yours truly - who wrote an entire book dedicated to debunking the many legends that still surround the 1972 report to the Club of Rome; the study prepared by a group of scientists of the Massachusetts Institute of Technology (not "by the Club of Rome", i.e "this group of persons" ).

I have seen all sorts of accusations against the Club of Rome, often written by people whose intelligence compares to that of invertebrates (with some advantage for invertebrates), assorted conspiracy theorists, politically motivated fanatics, and more. But here, come on, this is not a comment on a blog. It is a true micro-encyclopedia packed with data and diagrams. And it is a 2010 paper; it is recent. I mean, nowadays there is a debate on these matters - it is not any more the time when "Limits-bashing" was fashionable. Apart from my book, which was not out yet in 2010, there were plenty of scientific studies and Internet documents debunking the legend of the "errors of the Club of Rome". Already in 2008 I had written in "The Oil Drum" that the legend that the Limits study had predicted to total exhaustion of some resources by the year 2000 (or some other year) was just that: a legend that had originated from a paper written by Ronald Bailey on "Forbes" in 1989. There were no such statements in the Limits book.

But no way. And think that this specific paper is written by a single person and it must mark a milestone in that person's career. Think of the amount of work that must have gone into that. How can it be that the author didn't use a minimum of care to check that one of the first sentences of his masterpiece paper has no relation with reality?

It is the awesome power of legends. (really, at this point I think it is a law of physics)

Paving the planet: did someone say "anthropocene"?

This graph is taken from an article by Krausmann et al., (see below). It is not unexpected to see that the growth of all mineral commodities has been increasing during the past century. But what's impressive is the growth of "construction minerals" which stands for sand, rock, cement and the like. Incredibly fast: in terms of mass it is the largest produced mineral commodity over the planet. And even in more recent years, it shows no sign to be abating.


Think about that: 25 billion tons per year corresponds to more than three tons per person. Think of a ten kg cube of rock and cement delivered to you and deposited in front of your door every morning, every day of the year.

What drives this gigantic process? We seem to be engaged with incredible enthusiasm in the task of paving the planet. So far, it seems that we have been able to pave just a few percent of the planet's surface but, given the beauty of exponential growth, the day when we will have transformed the Earth into a shiny ball of concrete can't be too far away.


Did anyone say "anthropocene?"






Growth in global materials use, GDP and population during the 20th centuryFridolin Krausmann, Simone Gingrich, Nina Eisenmenger, Karl-Heinz Erb, Helmut Haberl, Marina Fischer-Kowalski, Ecological Economics Volume 68, Issue 10, 15 August 2009, Pages 2696–2705

The shale gas bubble: burning your home in order to save it

This is a written version of a comment that I made during the discussion at the last reunion of the Club of Rome in Ottawa.

Ladies and gentlemen, let me comment on a point of this interesting discussion. We have been told, correctly, that the production of shale gas in North America is booming and also that prices are now very low; around 2 dollars per million cubic feet. It is, actually, somewhat more than that but it is still a low price in comparison to what it was some years ago; before the shale gas "revolution"

On the other hand, producing shale gas is expensive. "Fracking" is a technology that was developed long ago, but it was never used on a large scale because it was too expensive in comparison to conventional gas production. And that's reasonable: for fracking you need sophisticated equipment, chemicals, and more. In addition, a shale gas well is rapidly exhausted, so that you must go on drilling in order to keep producing. Indeed, mining technology has this characteristic: it can be used to mobilize more resources, but it can rarely make them cheap.

So, there is a contradiction here: we are using a more expensive technology to produce a commodity whose prices, however, went down considerably. What's happening?

I think the explanation, here, lies in financial factors. What we are seeing, indeed, is mainly a financial bubble in which investors are led to pour money into a market with the hope to make a lot of money. That's a hope, obviously, for the future because, right now, I am sure that nobody can make a lot of money with such low gas prices - actually I think a lot of people are losing money. But this is the magic of the financial market: if everyone believes that a certain commodity will have a large value in the future, then they invest in it, and the result is overproduction.

So, we are talking of a financial bubble and we can compare the gas bubble with the housing bubble, the one that exploded in 2008. There is a difference, though: as the respective bubbles grew, home prices went up while gas prices went down. Well, there is a logic: we have very limited capability of storing the overproduction of gas - so we must burn it. In a way, we are burning gas in order to keep the gas market alive. That's not the case with overproduction of homes: you don't need to burn your home in order to save it; at least not so far (although sometimes rather drastic measures are needed) (*).

So, all that overproduced gas had to be sold on the market and that led to prices going down. It is what we are seeing. Now, the point is for how long the market will be willing to finance the production of something that is generating such small returns (if it is at all). Consider also that in the process we are also destroying water sources and polluting vast areas; to say nothing of the methane leaks resulting from drilling. All these are costs, too - someone will have to pay for them, sooner or later. So, I think we'll see prices going up - it is unavoidable. But that may cut the demand and may cause also production to go down. We seem to be seeing both effects ongoing, right now: lower production and higher prices. It is still too early to see a robust trend, here; but I think this is unavoidable - the shale gas revolution may be already over.

See also this article on shale gas by Ugo Bardi

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(*) An apartment building in Italy, near Ugo Bardi's home. Here, the owners couldn't rent the apartments at a price that they judged good enough, so they preferred to keep them vacant. To make sure that squatters won't come inside, they even walled up all doors and windows. They are waiting for the market to miraculously return to the high prices of once. Good luck!

Decoupling: where's the cake?

This is an expanded version of a short talk that I gave on Sep 21 2013 at the meeting of the Club of Rome in Ottawa. I added some figures and links, as well as the citation from Herman Daly.

If we want a bigger cake, the cook simply stirs faster in a bigger bowl and cooks the empty bowl into a larger oven that, somehow, heats itself - Herman Daly

Ladies and gentlemen, we are discussing now the question of "decoupling. So, first of all, what do we mean with this term? Well, decoupling is a concept based on the definition of "energy intensity" or "efficiency;" the ratio of the total energy consumption of a country to its gross domestic product, GDP.  It has often been observed that this ratio tends to go down for many countries. In this case, more GDP is generated for a unit of energy consumed and this is supposed to mean that people are learning to be smarter and more efficient in doing their jobs. In other words, it appears that we can "decouple "our ability of producing wealth from the need of consuming energy.

This idea reminds me a lot of something that Herman Daly, the economist, said some time ago. He compared the economy to making a cake. Your efficiency as a cook is how much flour (the energy) you need to make the cake divided by the size of the cake (the GDP). Some economists, Daly said, seem to think that you can make a cake without flour, just by stirring faster - that's "decoupling". Without needing to arrive to this rather extreme interpretation, the idea of "energy intensity" is that you are a good cook if you can keep making bigger and bigger cakes without the need of a proportional increase in the amount of flour.

It might work that way, although I have some doubts about this definition of efficiency. But let me tell you some data about Italy that may help you understand how these concepts may be applied to a practical case. Here are the latest data for energy intensity for Italy (from knoema):

So, it seems that Italy has shown a trend of improving efficiency; we could say it has been "decoupling". The trend seems to be slowing down, but it is still there today. So, this should be a good thing, but there is a problem. Let me show you Italy's GDP (again from Knoema)

And you see that Italy's GDP never recovered from the crisis of 2008. I could show you data for energy consumption in Italy but let me skip that: let me just say that it peaked in 2004 and it has been going down ever since. So, the energy intensity has been decreasing not because the GDP was growing, but because energy consumption was declining faster.

So, you see, maybe in Italy we should be happy because we are becoming more efficient but, as you surely understand, living in a country with a declining GDP is nothing to be happy about. Industries are closing, people are losing their jobs, there is no more money for things that once were taken for granted: social security, public health, public transportation and all that.

I was mentioning yesterday that the problem with Italy's economy is linked to the increasing costs of mineral commodities. I can cite from memory that in 2012 Italy imported 66 billion euros of fossil fuels and the net balance of imports or mineral commodities was negative for around 110 billion euros. That's surely not negligible in comparison to Italy's GDP which is around 1500 billion euros, especially if we consider that, not many years ago, the cost for imports was much smaller. We have today an additional burden on the economy that I estimate as around 70 billion euros in comparison with 10 years ago. It is money that must come from somewhere and it can only come from the pockets of Italian citizens. We are simply becoming poorer.

There is no evidence that the increasing prices of energy have caused the Italian economy to become more efficient. I can tell you that from my personal experience. You see, as university researchers, we are supposed to help companies to become more efficient, and we try to do our best. There are many ways of doing that: renewable energy, leaner manufacturing methods, better technologies, and more. I have been working on that for a long time; at least 20 years.

The problem is that, nowadays, when I tell to the managers of a company that they should be more efficient, they ask when they'll recover their investment. In the best cases, I can tell them that it could be  - say - in 3-4 years. Then they answer me that they can't say for sure if they'll still be open and producing next month; so they can't even dream of asking money to a bank (and paying a stiff interest on it) for becoming more efficient. They won't do anything unless the government pays, but the government doesn't have any more that kind of money.

So, you see, this is the situation in Italy - but I think it is a very general problem for many countries that have stopped growing. We are not becoming more efficient, we are not "decoupling." To do that, we would need resources - energy and minerals - but those resources are becoming more and more expensive. So, investing in efficiency is becoming expensive and we can't afford it.

In the end, we are back to Herman Daly's metaphor of the cake.  If you are a good cook you can make a big cake even with small amounts of flour. The problem is when the lack of flour forces you to make a smaller and smaller cake. Then, it is little consolation to note that you are an efficient cook; the problem is that people are asking "where's my cake?" and they are not happy at not having it. But there is no way out: in order to make a cake you need flour and in order to keep an economy functioning you need energy. In my view,  renewable energy is a prerequisite for decoupling - if we have clean energy, we can truly decouple and we'll even be forced to do it because not even cheap energy can re-create the minerals ores that we have destroyed. But, without energy, there will be just less and less cake for everybody.

Plundering the planet: an update

This is a written version of a talk I gave at the meeting of the club of Rome, in Ottawa, on Sep 19 2013.

Ladies and gentlemen, in this short talk I'll see to give to you an update of the status of the "Plundering the Planet" book,  which, as you know, is a report for the Club of Rome. And, as many of you know, the German version of the book was published in June of this year, so that I am in the interesting situation of having published a book that I can't read! But we are working at the English version, which should come out early next year.

Now, let me summarize for you the situation that "Plundering the Planet" describes. You surely have noticed that the title doesn't say "developing the planet" or "improving the planet". No, it says "plundering", which means exactly that: We are extracting mineral resources as if we were pirates plundering the coffers of a just stormed galleon.

So, where do we stand with mining? Well, it is a long story. I can tell you that the United States Geological Survey, the USGS, lists 88 mineral commodities and that's already a very respectable number. But it doesn't include, for instance, fossil fuels in their several varieties (gas, coal, oil, tar sands, shales, and the like). Then, every commodity has different sources, different areas of exploitation, different grades of products; as I said it is not easy to extricate oneself out of the mass of data available.

Anyway, I can tell you that we are in what looks like a situation of stability in the sense that the production of some commodities is growing, while for others is declining but, on the average, we don't see dramatic changes. I can tell you that right now the largest volumes produced is for construction materials: sand, cement, rock and the like. That's also the fastest growing mineral commodity in terms of production. It is growing exponentially, showing no signs of decline. It escapes me why we are working so hard to transform this planet into a sort of spherical highway, but this is the way things stand. Among metals, let me give you a couple of examples: copper production is growing, while that of gold is declining - in general we don't see dramatic changes for this category. If, then, we look at fossil fuels, the production of liquids (oil and other fuels), gaseous and solid (coal) fuels is weakly increasing on the average. But, of course, I have no intention to go through all the 88 commodities one by one. Let's say, as I was noting before, that we seem to be in a relatively stable situation - no decline on the average, but no rapid growth either.

The sensation, however, is also that we stand on the edge of a cliff and there are several factors that provide you with that sensation. The first one is prices. You see, there was a trend of price reduction that had been going on for at least a decade and everyone had noticed that: prices are going down, therefore there is no depletion problem. And then, starting with 2004: bang! We hit a vertical wall; prices have gone up and show no sign of going down. On the average, the price of such commodities as metals, has increased of a factor of three and that's not a negligible amount. Depletion does play a role in this, because it forces us to extract from lower grade resources.

If we then look at fossil fuels, you know the trend for the most important one: oil. Prices have increased of a factor of 5 in comparison to what we had about ten years ago. We are now consistently floating over 100 dollars per barrel. If you had said ten years ago that we would arrive to these levels, they you would have been considered a total madman (I remember that I said something like that at that time, but let me not go into the details.)

High prices are not the only problem with fossil fuels. There is the problem that we are succeeding in keeping production constant or increasing by means of the addition of liquids, such as biofuels, that contain less energy per unit volume than conventional oil. So, what we call "a barrel of oil" in 2013 contains less energy, on the average, than it used to contain ten years ago. And then there is the problem of net energy: depletion is forcing us to use more and more difficult resources and we need to use more energy to produce the same amount of energy. So, we are left with less energy that we can use for other purposes. And, finally, we have the fact that the economies of producing countries are growing and they tend to consume more for their internal market and export less. So, there is less oil available for non producing countries, which includes many Western countries.

So, you see, the situation can be described as very difficult. It is true that we can fight depletion and we have been doing that successfully, up to now. But it is a battle that we have won at a very high price (and only for a limited period of time). Apparently, however, we are willing to pay any price for oil, even at the cost of renouncing to a number of things that, once, were taken for granted, such as public health care, social security, public transportation, and the like.

It is a choice that we made and that we may well regret in the near future because we are not only beggaring ourselves but creating a much worse problem: a true climatic disaster. As depletion is forcing us to consume more energy in order to produce energy, the final result is that emissions are growing and they show no sign of abating.

Up to a few years ago there was a debate on whether peak oil would have saved us from ourselves. That is, if the "natural" decline of the production of fossil fuels could have caused a reduction in emissions and that would have solved the climate change problem. That debate is by now over: peak oil is not going to save us. It is arriving, but too late to stop catastrophic climate change.

In the end, the world's economy has been following quite closely the basic scenario that "The Limits to Growth" had outlined already in 1972. In a way, it is a triumph for the Club of Rome which had sponsored a study able to predict the future with such an accuracy. And, in the same sense, it is a monumental failure because we haven't been able to do anything to avoid the dire future we ourselves had been predicting. You know, it is like one of those nightmares where you are chased by a monster. You see the monster, you want to run away, but you can't. 

Yet, the first step to solving a problem is to understand it and the "Limits" study gave us the tools we need. And not just that: it gives us the tools needed to actually solve the problem. You see, what are trying to influence is a complex system: the world's economy. Complex systems have ways to oppose changes: it is the result of internal feedbacks that tend to stunt attempts from outside to budge the system from its stable condition (intended in a dynamic sense). So, attempts to change the system by brute force either don't work or they succeed in wrecking the system, which of course we don't want.

The way to steer complex systems is to identify their "leverage points" or "critical points": intervening on these levers it is possible to change things, it is a concept that arrives to us from Jay Forrester and Donella Meadows, respectively the originator and one of the authors of the "Limits" study. If we examine our present situation, it is clear that the leverage point, the critical point, is one: it is fossil fuels. We need fossil fuels, otherwise it wouldn't be possible to keep alive seven billion people on this planet, but unfortunately it is also true that we are wrecking the planet by burning fossil fuels. So we need to burn fossil fuels but we cannot burn them: it would seem to be a classic "no-win" situation.

The point is, however, that we don't need fossil fuels. What we need is something that fossil fuels provide: it is energy. And energy doesn't necessarily need to be produced using fossil fuels. So, the way of pushing the lever in the right direction is clear: if we can't stop and at the same time we can't continue, we need to use fossil fuels to replace fossil fuels,

That is, we need to use fossil fuels to produce the renewable plants that will replace fossil fuels (it may also be said about nuclear energy, although of course there are big problems with that). If we decide to do that, then there is a chance to solve the problem before it is too late. With a sufficient amount of clean energy we can keep our infrastructures functioning, keep alive seven billion people, and we can also keep mining; at reduced rates, of course, because depletion remains a problem. And we can't hope to continue our wasteful habits as we have been accustomed to, up to now; We'll need big changes in the way we do things: we'll have to be more efficient and way smarter. But with clean energy we can still supply the industrial system with minerals for many years and gradually adapt to a future less commodity-hungry industrial system. But we must do that fast and decisively: otherwise it will be too late.

So, this is the way I see the situation and I'd like to close this short presentation with a quote from William Stanley Jevons, who can well be said to have been the precursor of "The Limits to Growth" study. Already in his times, mid 19th century, and even before computers, he had very clear in his mind the dynamic factors of the problem and the crucial need for energy. So, here it is - he was actually speaking about coal, but I replaced the term "coal" with energy - Jevons would surely understand if he were with us today. For the problems we are facing, there are no miracles, no tricks, and no shortcuts: what we need is clean and abundant energy.

(from "The Coal Question", by William Stanley Jevons 1866)

Energy in truth stands not beside but entirely above all other  commodities. It is the material energy of the country — the universal aid — the factor in everything we do. With energy almost any feat is possible or easy; without it we are thrown back into the laborious poverty of early times.

Mineral resources and the limits to growth.

This is a shortened version of a talk I gave in Dresden on September 5, 2013. Thanks to Professor Antonio Hurtado for organizing the interesting conference there.

 

So, ladies and gentleman, let me start with this recent book of mine. It is titled "The Plundered Planet." You can surely notice that it is not titled "The Developed Planet" or "The Improved Planet." Myself and the coauthors of the book chose to emphasize the concept of "Plundering"; of the fact that we are exploiting the resources of our planet as if they were free for us for the taking; that is, without thinking to the consequences. And the main consequence, for what we are concerned here is called "depletion," even though we have to keep in mind the problem of pollution as well. 

Now, there have been many studies on the question of depletion, but "The Plundered Planet" has a specific origin, and I can show it to you. Here it is.  

It is the rather famous study that was published in 1972 with the title "The Limits to Growth". It was one of the first studies that attempted to quantify depletion and its effects on the world's economic system. It was a complex study based on the best available data at the time and that used the most sophisticated computers available to study how the interaction of various factors would affect parameters such as industrial production, agricultural production, population and the like. Here are the main results of the 1972 study, the run that was called the "base case" (or "standard run"). The calculations were redone in 2004, finding similar results. 

As you can see, the results were not exactly pleasant to behold. In 1972, the study saw a slowdown of the world's main economic parameters that would take place within the first two decades of the 21st century. I am sure that you are comparing, in your minds, these curves with the present economic situation and you may wonder whether these old calculations may be turning out to be incredibly good. But I would also like to say that these curves are not - and never were - to be taken as specific predictions. No one can predict the future, what we can do is to study tendencies and where these tendencies are leading us. So, the main result of the Limits to Growth study was to show that the economic system was headed towards a collapse at some moment in the future owing to the combined effect of depletion, pollution, and overpopulation. Maybe the economic problems we are seeing nowadays are a prelude to the collapse seen by this model, maybe not - maybe the predicted collapse is still far away in the future. We can't say right now.

In any case, the results of the study can be seen at least worrisome. And a reasonable reaction when the book came out in 1972 would have been to study the problem more in depth - nobody wants the economy to collapse, of course. But, as you surely know, the Limits to Growth study was not well received. It was strongly criticized, accused of having made "mistakes" of all kinds and at times to be part of a worldwide conspiracy to take control of the world and to exterminate most of humankind. Of course, most of this criticism had political origins. It was mostly a gut reaction: people didn't like these results and sought to find ways to demonstrate that the model was wrong (or the data, or the approach, or something else). If they couldn't do that, they resorted to demonizing the authors - that's nothing now; I described it in a book of mine "Revisiting the limits to growth".

Nevertheless, there was a basic criticism of the "Limits" study that made sense. Why should one believe in this model? What are exactly the factors that generate the expected collapse? Here, I must say, the answer often given in the early times by the authors and by their supporters wasn't so good. What the creators of the models said was that the model made sense according to their views and they could show a scheme that was this (from the 1972 Italian edition of the book):

Now, I don't know what do you think of it; to me it looks more or less like the map of the subway of Tokyo, complete with signs in kanji characters. Not easy to navigate, to say the least. So, why did the authors created this spaghetti model? What was the logic in it? It turns out that the Limits to Growth model has an internal logic and that it can be explained in thermodynamic terms. However, it takes some work to describe the whole story. So, let me start with the ultimate origin of these models:

If you have studied engineering, you surely recognize this object. It is called "governor" and it is a device developed in 19th century to regulate the speed of steam engines. It turns with the engine, and the arms open or close depending on speed. In so doing, the governor closes or opens the valve that sends steam into the engine. It is interesting because it is the first self-regulating device of this kind and, at its time, it generated a lot of interest. James Clerk Maxwell himself studied the behavior of the governor and, in 1868, he came up with a set of equations describing it. Here is a page from his original article

 

I am showing to you these equations just to let you note how these systems can be described by a set of correlated differential equations. It is an approach that is still used and today we can solve this kind of equations in real time and control much more complex systems than steam engines. For instance, drones. 

You see here that a drone can be controlled so perfectly that it can hold a glass without spilling the content. And you can have drones playing table tennis with each other and much more. Of course they are also machines designed for killing people, but let's not go into that. The point is that if you can solve a set of differential equations, you can describe - and also control - the behavior of quite complex systems.

The work of Maxwell so impressed Norbert Wiener, that it led him to develop the concept of "cybernetics"

We don't use so much the term cybernetics today. But the ideas that started from the governor study by Maxwell were extremely fecund and gave rise to a whole new field of science. When you use these equations for controlling mechanical system, you use the term "control theory." But when you use the equations for study the behavior of socio-economic systems, you use the term "system dynamics"

System dynamics is something that was developed mainly by Jay Wright Forrester in the 1950s and 1960s, when there started to exist computers powerful enough to solve sets of coupled differential equations in reasonable times. That generated a lot of studies, including "The Limits to Growth" of 1972 and today the field is alive and well in many areas.

A point I think is important to make is that these equations describe real world systems and real world systems must obey the laws of thermodynamics. So, system dynamics must be consistent with thermodynamics. It does. Let me show you a common example of a system described by system dynamics: practitioners in this field are fond of using a bathub as an example:

On the right you have a representation of the real system, a bathtub partly filled with water. On the left, its representation using system dynamics. These models are called "stock and flow", because you use boxes to represent stocks (the quantity of water in the tub) and you use double edged arrows to indicate flows. The little butterfly like things indicate valves and single edged arrows indicate relationship.

Note that I used a graphic convention that I like to use for my "mind sized" models. That is, I have stocks flowing "down", following the dissipation of thermodynamic potential. In this case what moves the model is the gravitational potential; it is what makes water flow down, of course. Ultimately, the process is driven by an increase in entropy and I usually ask to my students where is that entropy increases in this system. They usually can't give the right answer. It is not that easy, indeed - I leave that to you as a little exercise

The model on the left is not simply a drawing of box and arrows, it is made with a software called "Vensim" which actually turns the model "alive" by building the equations and solving them in real time. And, as you may imagine, it is not so difficult to make a model that describes a bathtub being filled from one side and emptied from the other. But, of course, you can do much more with these models. So, let me show a model made with Vensim that describes the operation of a governor and of the steam engine.

Before we go on, let me introduce a disclaimer. This is just a model that I put together for this presentation. It seems to work, in the sense that it describes a behavior that I think is correct for a governor (you can see the results plotted inside the boxes). But it doesn't claim to be a complete model and surely not the only possible way to make a system dynamics model of a governor. This said, you can give a look to it and notice a few things. The main one is that we have two "stocks" of energy: one for the large wheel of the steam energy, the other for the small wheel which is the governor. In order to provide some visual sense of this difference in size, I made the two boxes of different size, but that doesn't change the equations underlying the model. Note the "feedback", the arrows that connect flows and stock sizes. The concept of feedback is fundamental in these models.

Of course, this is also a model that is compatible with thermodynamics. Only, in this case we don't have a gravitational potential that moves the system, but a potential based on temperature differences. The steam engine works because you have this temperature difference and you know the work of Carnot and the others who described it. So, I used the same convention here as before; thermodynamic potential are dissipated going "down" in the model's graphical representation

Now, let me show you another simple model, the simplest version I can think of a model that describes the exploitation of non renewable resources:

It is, again, a model based on thermodynamics and, this time, driven by chemical potentials. The idea is that the "resources" stock as a high chemical potential in the sense that it may be thought as, for instance, crude oil, which spontaneously combines with oxygen to create energy. This energy is used by human beings to create what I can call "capital" - the sum of everything you can do with oil; from industries to bureaucracies.

On the right, you can see the results that the model provides in terms of the behavior as a function of time of the stock of the resources, their production, and the capital stock. You may easily notice how similar these curves are to those provided by the more complex model of "The Limits to Growth." So, we are probably doing something right, even with this simple model.

But the point is that the model works! When you apply it to real world cases, you see that its results can fit the historical data. Let me show you an example:

This is the case of whaling in 19th century, when whale oil was used as fuel for lamps, before it became common to use kerosene. I am showing to you this image because it is the first attempt I made to use the model and I was surprised to see that it worked - and it worked remarkably well. You see, here you have two stocks: one is whales, the other is the capital of the whaling industry that can be measured by means of a proxy that is the total tonnage of the whaling fleet. And, as I said, the model describes very well how the industry grew on the profit of killing whales, but they killed way too many of them. Whales are, of course, a renewable resource; in principle. But, of course, if too many whales are killed, then they don't have enough time to reproduce and they behave as a non-renewable resource. Biologists have determined that at the end of this fishing cycle, there were only about 50 females of the species being hunted at that time. Non renewable, indeed!

So, that is, of course, one of the several cases where we found that the model can work. Together with my co-workers, we found that it can work also for petroleum extraction, as we describe in a paper published in 2009 (Bardi and Lavacchi). But let me skip that - the important thing is that the model works in some cases but, as you would expect, not in all. And that is good - because what you don't want is a "fit-all" model that doesn't tell you anything about the system you are studying. Let's say that the model reproduces what's called the "Hubbert model" of resource exploitation, which is a purely empirical model that was proposed more than 50 years ago and that remains a basic one in this kind of studies: it is the model that proposes that extraction goes through a "bell-shaped" curve and that the peak of the curve, the "Hubbert peak" is the origin of the concept of "peak oil" which you've surely heard about. Here is the original Hubbert model and you see that it has described reasonably well the production of crude oil in the 48 US lower states.

Now, let's move on a little. What I have presented to you is a very simple model that reproduces some of the key elements of the model used for "The Limits to Growth" study but it is of course a very simplified version. You may have noted that the curves for industrial production of the Limits to Growth tend to be skewed forward and this simple model can't reproduce that. So, we must move of one step forward and let me show you how it can be doing while maintaining the basic idea of a "thermodynamic cascade" that goes from higher potentials to lower potentials. Here is what I've called the "Seneca model"

You see that I added a third stock to the system. In this case I called it "pollution"; but you might also call it, for instance, "bureaucracy" or may be even "war". It is any stock that draws resource from the "Capital" (aka, "the economy") stock. And the result is that the capital stock and production collapse rather rapidly; this is what I called "the Seneca effect"; from the roman philosopher Lucius Anneaus Seneca who noted that "Fortune is slow, but ruin is rapid".

For this model, I can't show you specific historical cases - we are still working on this idea, but it is not easy to make quantitative fittings because the model is complicated. But there are cases of simple systems where you see this specific behavior, highly forward skewed curves - caviar fishing is an example. But let me not go into that right now.

What I would like to say is that you can move onward with this idea of cascading thermodynamic potentials and build up something that may be considered as a simplified version of the five main stocks taken into account in the "Limits to Growth" calculations. Here it is

Now, another disclaimer: I am not saying that this model is equivalent to that of the Limits to Growth, nor that it is the only way to arrange stocks and flows in order to produce similar results to the one obtained by the Limits to Growth model. It is here just to show to you the logic of the model. And I think you can agree, now, that there is one. The "Limits" model is not just randomly arranged spaghetti, it is something that has a deep logic based on thermodynamics. It describes the dissipation of a cascade of thermodynamic potentials.

In the end, all these model, no matter how you arrange their elements, tend to generate similar basic results: the bell shaped curve; the one that Hubbert had already proposed in 1956

The curve may be skewed forward or not, but that changes little on the fact that the downside slope is not so pleasant for those who live it.

Don't expect this curve to be a physical law; after all it depend on human choices and human choices may be changed. But, in normal conditions, human beings tend to follow rather predictable patterns, for instance exploiting the "easy" resources (those which are at the highest thermodynamic potential) and then move down to the more difficult ones. That generates the curve.

Now, I could show you many examples of the tendency of real world systems to follow the bell shape curve. Let me show you just one; a recent graph recently made by Jean Laherrere.

These are data for the world's oil production. As you can see, there are irregularities and oscillations. But note how, from 2004 to 2013, we have been following the curve: we move on a predictable path. Already in 2004 we could have predicted what would have been today's oil production. But, of course, there are other elements in this system. In the figure on the right, you can see also the appearance of the so-called "non-conventional" oil resources, which are following their own curve and which are keeping the production of combustible liquids (a concept slightly different from that of "crude oil) rather stable or slightly increasing. But, you see, the picture is clear and the predictive ability of these models is rather good even though, of course, approximate.

Now, there is another important point I'd like to make. You see, these models are ultimately based on thermodynamics and there is an embedded thermodynamic parameter in the models that is called EROI (or EROEI) which is the energy return for the energy invested. It is basically the decline in this parameter that makes, for instance, the extraction of oil gradually producing less energy and, ultimately, becoming pointless when the value of the EROEI goes below one. Let me show you an illustration of this concept:

You see? The data you usually read for petroleum production are just that: how much petroleum is being produced in terms of volume. There is already a problem with the fact that not all petroleums are the same in the sense of energy per unit volume, but the real question is the NET energy you get by subtracting the energy invested from the energy produced. And that, as you see, goes down rapidly as you move to more expensive and difficult resources. For EROEIs under about 20, the problem is significant and below about 10 it becomes serious. And, as you see, there are many energy resources that have this kind of low EROEI. So, don't get impressed by the fact that oil production continues, slowly, to grow. Net energy is the problem and many things that are happening today in the world seem to be related to the fact that we are producing less and less net energy. In other words, we are paying more to produce the same. This appears in terms of high prices in the world market.

Here is an illustration of how prices and production have varied during the past decades from the blog "Early Warning" kept by Stuart Staniford.

And you see that, although we are able to manage a slightly growing production, we can do so only at increasingly high prices. This is an effect of increasing energy investments in extracting difficult resources - energy costs money, after all.
So, let me show you some data for resources that are not petroleum. Of course, in this case you can't speak in terms of EROEI; because you are not producing energy. But the problem is the same, since you are using fossil fuels to produce most of the commodities that enter the industrial system, and that is valid also for agriculture. Here are some data.

Food production worldwide is still increasing, but the high costs of fossil fuels are causing this increase in prices. And that's a big problem because we all know that the food demand is highly anelastic - in plain words you need to eat or you die. Several recent events in the world, such as wars and revolutions in North Africa and Middle East have been related to these increases in food prices.

Now, let me go to the general question of mineral production. Here, we have the same behavior: most mineral commodities are still growing in terms of extracted quantities, as you can see here (from a paper by Krausmann et al, 2009 http://dx.doi.org/10.1016/j.ecolecon.2009.05.007)

These data go up to 2005 - more recent data show signs of plateauing production, but we don't see clear evidence of a peak, yet. This is bad, because we are creating a climate disaster. As you seee from the most recent data, CO2 are still increasing in a nearly exponential manner

 

But the system is clearly under strain. Here are some data relative to the average price index for aluminum, copper, gold, iron ore, lead, nickel, silver, tin and zinc (adapted from a graphic reported by Bertram et al., Resource Policy, 36(2011)315)

So, you see, there has been this remarkable "bump" in the prices of everything and that correlates well with what I was arguing before: energy costs more and, at the same time, energy requirements are increasing because of ore depletion. At present, we are still able to keep production stable or even slowly increasing, but this is costing to society tremendous sacrifices in terms of reducing social services, health care, pensions and all the rest. And, in addition, we risk to destroy the planetary ecosystem because of climate change.

Now I can summarize what I've been saying and get to the take-home point which, I think can be expressed in a single sentence "Mining takes energy"

Of course, many people say that we are so smart that we can invent new ways of mining that don't require so much energy. Fine, but look at that giant wheel, above, it used to extract coal in the mine of Garzweiler in Germany. Think of how much energy you need to make that wheel; do you think you could use an i-pad, instead?

In the end, energy is the key of everything and if we want to keep mining, and we need to keep mining, we need to be able to keep producing energy.  And we need to obtain that energy without fossil fuels. That's the concept of the "Energy Transition"

Here, I use the German term "Energiewende" which stands for "Energy Transition". And I have also slightly modified the words by Stanley Jevons, he was talking about coal, but the general concept of energy is the same. We need to go through the transition, otherwise, as Jevons said long ago, we'll be forced to return to the "laborious poverty" of older times.

That doesn't mean that the times of low cost mineral commodities will ever return but we should be able to maintain a reasonable flux of mineral commodities into the industrial system and keep it going. But we'll have to adapt to less opulent and wasteful life as the society of "developed" countries has been accustomed so far. I think it is not impossible, if we don't ask too much:

h/t ms. Ruza Jankovich - the car shown here is an old Fiat "500" that was produced in the 1960s and it would move people around without the need of SUVs

____________________________________________


Acknowledgement:

The Club of Rome team

Daphne Davies
Ian Johnson
Linda Schenk
Alexander Stefes
Joséphine von Mitschke-Collande
Karl Wagner

And the coauthors of the book "Plundering the Planet"

Philippe Bihouix
Colin Campbell
Stefano Caporali
Partick Dery
Luis De Souza
Michael Dittmar
Ian Dunlop
Toufic El Asmar
Rolf Jakobi
Jutta Gutberlet
Rui Rosa
Iorg Schindler
Emilia Suomalainen
Marco Pagani
Karl Wagner
Werner Zittel

The next ten billion years: vidcast

Discussing the next ten billion years at the "Doomstead Diner". A follow up of my previous posts on the subject (first one and second one).

The next ten billion years revisited

Thou must now at last perceive of what universe thou art a part, and of what administrator of the universe thy existence is an efflux, and that a limit of time is fixed for thee, which if thou dost not use for clearing away the clouds from thy mind, it will go and thou wilt go, and it will never return. (Marcus Aurelius, "Meditations")

You can't understand a man's actions if you don't take into account that what he does on a specific day is the result of events that took place during his whole lifetime and that will result in more events in the future. It is the same for a whole planet, although the lifespan of the Earth is much longer than that of a single human being. If we want to understand what's happening today on our planet, we must try to understand how it has changed over the eons to become what it his now and what it may become in the future.

That of looking at the whole span of the history of a whole planet or even of the whole universe has a special flavor; even though none of us will ever witness the ultimate end of our biosphere, still the idea that we can imagine it is a source of great fascination. And it is not something new: it is a whole field of human thought that we can call "eschatology", from the Greek world "eskhatos", meaning "the last".

In the history of people musing on the ultimate end of everything, we can see two lines of thought that we might dub, purely for convenience, the "Western" and the "Eastern" views. The Western view sees the universe, humans and everything, as having a finite and limited lifespan, the Eastern view sees the same concepts as an infinite series of cycles. The single cycle view is typical of thinkers steeped in the Greek-Latin tradition and of the monotheistic religions that arose around the Mediterranean area. In its basic form, the idea is that God created the world and that the world will have an end (apocalypse, from a Greek world meaning "revelation"). Human beings are supposed to live a one-time trial. You succeed or you don't, but God doesn't give you another chance. East-Asian thought seems to have been based on a different viewpoint: Buddhism sees the soul as forever reincarnating in new bodies. There is no end and no beginning to this endless cyucle that the wise may, however, be able to interrupt.

It is hard to say what factors created these two different schools of thought. One thing we know, however, is that today Western science can be seen as continuing the ancient tradition, that of the single cycle. For what we know, the universe appeared in a specific event called the "Big Bang" and it is destined to end, according to the most recent data, as a cold and dreary place made out of matter scattered over an immensely large volume. Back in  1956, Isaac Asimov was reasoning within this tradition when he wrote a story titled "The Last Question", where he imagined humankind engaged in a forever quest for how to reverse the cycle and rejuvenate the universe. But Asimov was also thinking outside the Western box when he proposed at the end that the question could be answered, although not by humans themselves but by the computer they had created. As there is nobody to tell the answer to, the computer proceeds to carry on the answer in practice by creating light and restarting the universe.

I must have read this old story by Isaac Asimov when I was, maybe, 15 years old and it inspired a post that I wrote on "Cassandra's Legacy" with the title "The Next Ten Billion Years" for which I borrowed from Asimov the same finale. This post of mine had a certain success and, recently, John Michael Greer ("The Archdruid") commented on it and produced his own version of the next ten billion years as he sees them. It is by all means a fascinating piece but different from mine in a deep philosophical sense. True to his role of druid, Greer explicitly rejects the Christian "one-cycle" tradition and leans on the multiple cycle view of the universe, for instance saying that, ten million years from now,

No fewer than 8,639 global civilizations have risen and fallen over the last ten million years, each with its own unique sciences, technologies, arts, literatures, philosophies, and ways of thinking about the cosmos.

and then he goes on to describe several non-human civilizations arising and disappearing in the span of several hundred million years, including one derived from raccoons, one from ravens, and one from freshwater clams. There is no evidence in Greer's vision of the entropy caused winding down of the universe. The atoms that once formed the Earth and its inhabitants are flung away in space by the last convulsion of the Sun and end up forming another star and a number of planets. The cycle restarts.

As I said, we are discussing philosophical matters and we'll never find an agreement on what the Earth will look like - say - ten million years from now. So, I'll just comment here on how science gives us very strong evidence for a "one-cycle" Earth. With that, I don't mean just an apocalyptic end of our planet when it will be finally consumed by an expanding Sun. No, the Earth has changed all the time over its four billion years of existence, it keeps changing, and the changes are profound and irreversible.

What we call the "biosphere" has been part of this great, long lasting cycle. As all things that are born and are destined to die, the biosphere must peak and decline. Actually, it has peaked and it is declining. The biosphere productivity over the past 3.5 billion years looks a little like a gigantic Hubbert peak according to a paper by Franck, Bounama and Von Bloh,

In a previous post, I wrote about this graph that:

As you see, the Earth's biosphere, Gaia, peaked with the start of the Phanerozoic age, about 500 million years ago. Afterwards, it declined. Of course, there is plenty of uncertainty in this kind of studies, but they are based on known facts about planetary homeostasis. We know that the sun's irradiation keeps increasing with time at a rate of around 1% every 100 million years. That should have resulted in the planet warming up, gradually, but the homeostatic mechanisms of the ecosphere have maintained approximately constant temperatures by gradually lowering the concentration of CO2 in the atmosphere. However, there is a limit: the CO2 concentration cannot go below the minimum level that makes photosynthesis possible; otherwise Gaia "dies".

So, at some moment in the future, planetary homeostasis will cease to be able to stabilize temperatures. When we reach that point, temperatures will start rising and, eventually, the earth will be sterilized. According to Franck et al., in about 600 million years from now the earth will have become too hot for multicellular creatures to exist.

Of course, the extinction of the biosphere is not for tomorrow or, at least, the calculations say so. But it is like estimating one's lifespan from statistical data. Theoretically, the homeostatic mechanisms that operate your body could keep you alive until reach a respectable age; sure, but homoeostasis is never perfect. For instance, there are mechanisms in your body designed to reverse the effects of traumas. You may expect these mechanisms to work well if you are young but, if you are hit by a truck at full speed, well, you end up on the wrong side of the life expectancy statistics.

Similar considerations apply to Gaia. Theoretically, the planetary homeostatic mechanisms should keep Gaia alive for hundreds of millions of years, but what about major perturbations, some planetary equivalent of being hit by a truck? Would Gaia be able to recover from a human caused runaway greenhouse catastrophe?

We cannot say for sure. What we can say is that we are living in a period called the "sixth extinction," similar to other major past extinctions. In most cases, these extinctions appear to have been caused by an increase in the concentration of greenhouse gases in the atmosphere. The sixth extinction, too, is taking place in correspondence to a rise of the concentration of carbon dioxide in the atmosphere that may never have happened so fast in the history of the planet. This rapid rise is also taking place under a solar irradiation that has never been so high as it is today. We can't rule out that the sixth extinction will be the last one.

So, as I said at the beginning, the present and the future of a single person can be understood from his or her past, and it is the same for the Earth (aka, "Gaia"). Science is telling us very, very strongly that the present moment is unique in the history of the planet: the future will not be like the past. It is true that, if we fail to survive as a civilization, there will be probably space for more human civilizations. And, if we go extinct, there may be space for the evolution of new sentient species. But all that will happen in different conditions and along a downward slope.

New human civilizations developing within the next few hundred thousand years will not have the coal and the fossil hydrocarbons that we have consumed today. In a few hundred million years from now, new sentient species might find oil that has reformed in shallow anoxic seas - but they won't have coal, the result of very special conditions occurring only once (for what we know) on this planet. And they will live in a planet with a much reduced biological productivity in comparison to ours. That doesn't mean that they won't be able to develop spaceflight, as Greer proposes - the future is full of opportunities, but it is never like the past.

In the end, these considerations give us just a hint of the sheer immensity of the future and of how difficult is the human attempt to conceive it. For what we know, we are a small ripple on the top of a gigantic tsunami wave that's crashing on some remote shore. As a ripple disappears, new ones appear, but the wave keeps rolling onward to its inevitable end. And yet, we know so little: there may be other shores, other waves, the universal sea may never stop to roll, and light and darkness may exchange places in a never ending dance. So, just as Asimov concluded his story, someday, the words "Let there be light" may be said again. And there will be light again.  



All-pervading,
ever moving.
So it can act as the mother
of all things.
Not knowing its real name
we only call it the Way

If it must be named, 
let its name be Great.
Greatness means going on,
going on means going far,
and going far means turning back

(Tao Te King, as reported by Ursula K. Le Guin)

If we have to use fossil fuels to manufacture renewable plants, doesn't it mean that renewables are useless?

In this post, Marco Raugei makes a fundamental point about an often raised question: if we have to use fossil fuels to manufacture renewable plants, doesn't it mean that renewables are useless? Raugei's answer is a resounding "no". In fact, the EROEI of fossil fuels acts as a multiplier for the final EROEI of the whole process. It turns out that if we invest the energy of fossil fuels to build renewable plants we get an overall EROEI around 20 for a process that leads to photovoltaic plants and an even better one for wind plants. So, if we want to invest in our future, that's the way to go, until we gradually arrive to completely replace fossil fuels! (image above from "The Energy Collective")

The EROI and promise of PV (and other renewables). Trying to avoid unnecessary inconsistency and confusion, and to keep an open mind and a balanced viewpoint.

by Marco Raugei

The energy return on energy investment (acronym: EROI or EROEI) provides a numerical quantification of the benefit that the user gets out of the exploitation of an energy source, in terms of “how much energy is gained from an energy production process compared to how much of that energy (or its equivalent from some other source) is required to extract, grow, etc., a new unit of the energy in question” [1].

As straightforward as this definition may sound, when dealing with the diverse range of existing energy sources and technologies, the devil is in the details.

It goes without saying that, in order to ensure comparability, it would be wise to at least approach all EROI studies of different energy technologies by applying a strictly consistent methodology, including the all-important aspect of system boundaries (i.e. what should be included and what not). Otherwise, a reported lower extended-boundary EROI for any given new energy technology may (artfully or artlessly) be taken out of context by readers who have their own axe to grind (or who are just too eager to oversimplify), and then used to incorrectly single out that particular technology as a worse performer vis-à-vis more conventional ones (typically, fossil fuel-fired electricity production).
An instance of such a potentially tricky situation has recently arisen with the publication of a book on the EROI of the photovoltaic (PV) sector in Spain [2].

One aspect of the controversy is rooted in the fact that the interdependence of PV and fossil fuels is not ‘symmetrical’ – no-one in their right mind could claim otherwise - and hence the EROI of PV is affected by the EROI of the fossil fuels (oil, coal, and gas) that underpin it. Additionally, fossil fuel technologies are much more ‘mature’, and much of the necessary infrastructure for their operation (rigs, pipelines, roads, etc.) was developed long ago and has largely been amortized already. As a result, it may well be that extending the boundaries of the EROI analysis for fossil fuel-based technologies may end up making a smaller difference vs. doing the same for newer technologies such as PV.

Yet, it seems that this argument is too often brought up to imply that, since PV development and deployment is currently (largely) underpinned by fossil energy, and hence PV is not (yet) a fully independent and truly 100% renewable energy technology, then "why bother" in the first place?
Actually, this kind of critique is aimed at countering the incurable technological optimists' view that "there is nothing to worry about: we can continue unabated in our reckless business-as-usual overconsumption of energy (and resources) because soon PV (and other renewables) will seamlessly step in and take the baton from dirty fossil fuels, and all will be well".

Such through-rose-tinted-glasses optimism is most likely wrong-headed and should probably be tamed. But it is also worth looking at the issue from another angle. Let us assume that the average EROI of the current mix of fossil fuels (which still represent our main sources of primary energy, globally) is some value X > 1. And let us also agree that we (as a society) need a large and ever-growing share of our energy budget in the form of electricity (to power our computers, telecommunications, trains, home appliances, etc).

Broadly speaking, we therefore have two options:

1) keep using all the oil (and other fossil fuels) directly as FEEDSTOCK fuel in conventional power plants. In so doing, we would get out roughly 1/3 of the INPUT energy as electricity (electricity production efficiency in conventional power plants being ~0.33). This would be the "quick and dirty" option, that maximizes the short-term (almost instantaneous, in fact) "bang for the buck".

2) Use the same amount of available oil (and other fossil fuels) as (direct and indirect) INPUT for the production of PV plants.

Building and deploying a modern crystalline silicon PV system requires approximately 3 GJ of primary energy per m2 (note that this value takes into account the conversion to electricity at ~0.33 efficiency prior to use in the PV manufacturing operations which are carried out using electric power). When installed in southern Europe (irradiation = 1,700 kWh/(m2*yr)), such system, operating at an average efficiency of 13% (reference) * 80% (performance ratio) = 10%, will produce approximately 5 MWh (= 18 GJ) of electricity per m2 over its 30-year lifetime [3,4]. What this means is that the c-Si PV system would provide an output of electricity roughly equal to 18/3 = 6 times its primary energy input, which corresponds about 6/0.33 = 18 times the amount of electricity that we would have obtained, had we burnt the fuel(s) as FEEDSTOCK in conventional power plants (option 1 above), instead of using them as INPUT for the PV plant.

Of course, we cannot afford to switch to option 2 tout-court overnight, for a number of technical as well as systemic reasons [5]. First and foremost, we simply would not be left with enough energy output in the short term to sustain and power our complex society. But an almost 20x improvement in the efficiency with which we use our limited and dwindling endowment of fossil fuels must be worth at least some consideration.

A planned long-term investment might be advisable, for instance, aimed at bringing about a gradual transition. The latter is in fact what many have been advocating, often only to be met with rather negative ‘gloom and doom’ reactions by others on a number of prominent discussion forums. It seems as if, in the minds of the latter, the desire to show that ‘the emperor has no clothes’ (i.e. that PV and other renewables are not yet, and might never be in full, a real, completely independent and high-EROI alternative to fossil fuels) overrides all other considerations, and prevents them from realizing/admitting that, after all, it may still be reasonable and recommendable to try and push this slow transition forward.

To conclude, I would like to dispel all doubts and clearly state that I do agree with the aforementioned ‘pessimists’ that if we (as a society) do not come to grips with the notion that there is no such thing as infinite growth on a finite planet [6,7], and re-align our goals and ‘development’ strategies accordingly, then all the technological fixes in the world stand little to no chance of being enough to avert an ominous crash. But, why write off PV (and other renewables) and deny their value as useful tools to (hopefully) help us out on a safe slide along the slopes of a "prosperous way down" [8]?

References:

1. Murphy D.J., Hall C.A.S., 2010. Year in review – EROI or energy return on (energy) invested. Ann. N.Y. Acad. Sci. 1185:102-118
2. http://spectrum.ieee.org/green-tech/solar/argument-over-the-value-of-solar-focuses-on-spain
3. Fthenakis V.M., Held M., Kim H.C., Raugei M., 2009. Update of Energy Payback Times and Environmental Impacts of Photovoltaics. 24th European Photovoltaic Solar Energy Conference and Exhibition; Hamburg, Germany
4. Fthenakis V.M., Kim H.C., 2011. Photovoltaics: Life-cycle analyses. Solar Energy 85(8): 1609-1628
5. Smil V., 2010. Energy Transitions: History, Requirements, Prospects. Praeger, ISBN-13: 978-0313381775
6. Meadows, D H., Meadows D.L., Randers J., Behrens W., 1972. Limits to Growth. Signet, ISBN-13: 978-0451057679
7. Bardi U., 2011. The Limits to Growth Revisited. Springer, ISBN-13: 978-1441994158
8. Odum, H.T., Odum E.C., 2001. A Prosperous Way Down. Colorado University Press, ISBN-13: 978-0870819087