Monday, August 14, 2017

Which EROI do we need to collect berries?



My wife, Grazia, collecting berries in the woods of Tuscany in a hot day of August. Maybe her ancestors were doing exactly the same, more or less in the same place, hundreds or thousands of years ago. Here, I present some reflections and some calculations showing that the EROI of this simple way of collecting food may be over 100, better than almost anything we have nowadays. Of course, no empire in history was based on hunting and gathering, but was that a bad thing?


The question of EROI - the energy return on energy invested - is raging nowadays, with some people insisting that a civilization cannot exist without an EROI of at least variously estimated values, at least 10 and higher (image on the right by Charles Hall). And that is said to mean we absolutely need sophisticated technologies, such as nuclear, in order to survive.

Yet, this morning I had been collecting berries in the wood with my wife and wondering: 'what is the EROI of what we are doing?' A reasonably good EROI, I am sure, enough for what our ancestors needed when they survived on hunting and gathering. All you have to do is to walk in the woods, find the berries and pick them up (and watch your step, you don't want to fall into a thorn bush).  If our hunter-gatherer ancestors used this method, and if we are here today - their descendants - it means it was an effective strategy for survival. Collecting what you can find is an ancient and tested strategy that goes under the name of "gleaning" and it has accompanied humankind for millennia. It is a good strategy just because it is so simple: no tools, no written laws, no overlords, no police, no fences. And it works.

As I was collecting berries, I started thinking things. How to program a drone to collect berries, for instance. Sure: a perfect way to bring down the EROI of the whole thing to nearly zero. And to destroy the bushes forever. Humans are like this, with their attempt of "improving" things they always pull the levers in the wrong direction. And that means making things more complicated, needing more and more energy to keep them running, and then complaining that we don't have enough.

Of course, with more than seven billion humans on this planet, it is hard to think that we can go back to gleaning to feed them all. But for how long we can trust the expensive, complex, delicate, and terribly inefficient enterprise we call "industrial agriculture"? I can't say. What I can say is that collecting berries is a big satisfaction, as you see below.





And now some approximate calculations: Today we collected 2 kg of berries. According to the available data, berries contain 125 kJ/100g. So, the total collection was about 2500 kJ, about 700 Wh.

Now, it was about one hour of low-intensity work for two people, so let's say it involved a total of 50x2x1h = 100 Wh of human work. Then, I found values of 20-25% for the human metabolic efficiency of converting food to mechanical energy, it means we consumed some 400-500 Wh of food energy in order to collect 700 Wh.

Very approximate, or course, but the final result is an EROI = 1.4-1.7. Not comparable to crude oil, but probably more than enough for our ancestors to enjoy berries as a seasonal treat.

But, of course, no one ever lived on berries alone, not even in paleolithic times. The energy content of several kinds of foods that you can find in a natural environment may be more than an order of magnitude larger than that of blackberries. Walnuts are reported to have more than 10,000 kJ/100 g. If you can collect one kg/hour, as we did for berries, it means an EROI of more than 100 (!!). Larger than the mythical EROI of crude oil of a hundred years ago. Wheat and cereals, in general, have also high energy content, wheat is reported to have 15,000 kJ/kg, showing how gleaning could be an extremely efficient food gathering strategy.

So, life was simple and easy, once, until we decided to make it complicated and difficult.






Thursday, August 10, 2017

Our Photovoltaic Future: the Next Five Billion Years

As part of a series of posts on photovoltaic energy as a metabolic revolution of the earth's ecosystem, I am reproposing a post that I published last year on "Cassandra's Legacy" with the title "Five Billion Years of Energy Supply". 



It seems to be popular nowadays to maintain that photovoltaic energy is just an "extension" of fossil energy and that it will fade away soon after we run out of fossils fuels. But photovoltaics is much more than just a spinoff of fossil energy, it is a major metabolic revolution in the ecosystem, potentially able to create a "stereosphere" analogous to the "biosphere" that could last as long as the remaining lifetime of the earth's ecosystem and possibly much more. Here are some reflections of mine, not meant to be the last word on the subject, but part of an ongoing study that I am performing. You can find more on a similar subject in a paper of mine on Biophysical Economics and Resource Quality, (BERQ)






"Life is nothing but an electron looking for a place to rest," is a sentence attributed to Albert Szent-Györgyi. It is true: the basis of organic life as we know it is the result of the energy flow generated by photosynthesis. Sunlight promotes an electron to a high energy state in the molecule of chlorophyll. Then, the excited electron comes to rest when a CO2 molecule reacts with hydrogen stripped away from an H2O molecule in order to form the organic molecules that are the basis of biological organisms. That includes replacing degraded chlorophyll molecules and the chloroplasts that contain them with new ones. The cycle is called "metabolism" and it has been going on for billions of years on the earth's surface. It will keep going as long as there is sunlight to power it and there are nutrients that can be extracted from the environment. 

But, if life means using light to excite an electron to a higher energy state, there follows that chlorophyll is not the only entity that can do that. In the figure at the beginning of this post, you see the solid state equivalent of a chlorophyll molecule: a silicon-based photovoltaic cell. It promotes an electron to a higher energy state; then this electron finds rest after having dissipated its potential by means of chemical reactions or physical processes. That includes using the potentials generated to manufacturing new photovoltaic cells and the related structures to replace the degraded ones. In analogy with the biological metabolism, we could call this process "solid state metabolism". Then, the similarities between the carbon-based metabolic chain and the silicon-based one are many. So much that we could coin the term "stereosphere" (from the Greek term meaning "solid.") as the solid-state equivalent of the well known "biosphere". Both the biosphere and the stereosphere use solar light as the energy potential necessary to keep the metabolic cycle going and they build-up metabolic structures using nutrients taken from the earth's surface environment.

The main nutrient for the biosphere is CO2, taken from the atmosphere, while the stereosphere consumes SiO2, taking it from the geosphere. Both metabolic chains use a variety of other nutrients: the stereosphere can reduce the oxides of metals such as aluminum, iron, and titanium, and use them as structural or functional elements in their metallic form; whereas the biosphere can only use carbon polymers. The biosphere stores information mostly in specialized carbon-based molecules called deoxyribonucleic acids (DNA). The stereosphere stores it mostly in silicon-based components called "transistors". Mechanical enactors are called "muscles" in the biosphere and are based on protein filaments that contract as a consequence of changing chemical potentials. The equivalent mechanical elements in the stereosphere are called "motors" and are based on the effects of magnetic fields on metallic elements. For each element of one of these systems, it is possible to find a functional equivalent of the other, even though their composition and mechanisms of operation are normally completely different.

A major difference in the two systems is that the biosphere is based on microscopic self-reproducing cells. The stereosphere, instead, has no recognizable cells and the smallest self-reproducing unit is something that could be defined as the "self-reproducing solar plant factory." A factory that can build not only solar plants but also new solar plant factories. Obviously, such an entity includes a variety of subsystems for mining, refining, transporting, processing, assembling, etc. and it has to be very large. Today, all these elements are embedded in the system called the "industrial system." (also definable as the "technosphere"). This system is powered, at present, mainly by fossil fuels but, in the future, it would be transformed into something fully powered by the dissipation of solar energy potentials. This is possible as long as the flow of energy generated by the system is as large or larger than the energy necessary to power the metabolic cycle. This requirement appears to be amply fulfilled by current photovoltaic technologies (and other renewable ones).

A crucial question for all metabolic processes is whether the supply of nutrients (i.e. minerals) can be maintained for a long time. About the biosphere, evidently, that's the case: the geological cycles that reform the necessary nutrients are part of the concept of "Gaia", the homeostatic system that has kept the biosphere alive for nearly four billion years. About the stereosphere, most of the necessary nutrients are abundant in the earth's crust (silicon and aluminum being the main ones) and easily recoverable and recyclable if sufficient energy is available. Of course, the stereosphere will also need other metals, several of which are rare in the earth's crust, but the same requirement has not prevented the biosphere from persisting for billions of years. The geosphere can recycle chemical elements by natural processes, provided that they are not consumed at an excessively fast rate. This is an obviously complex issue and we cannot exclude that the cost of recovering some rare element will turn out to be a fundamental obstacle to the diffusion of the stereosphere. At the same time, however, there is no evidence that this will be the case.

So, can the stereosphere expand on the earth's surface and become a large and long-lasting metabolic cycle? In principle, yes, but we should take into account a major obstacle that could prevent this evolution to occur. It is the "Allee effect" well known for the biosphere and that, by similarity, should be valid for the stereosphere as well. The idea of the Allee effect is that there exists  a minimum size for a biological population that allows it to be stable and recover from perturbations. Too few individuals may not have sufficient resources and reciprocal interactions to avoid extinction after a collapse. In the case of the stereosphere, the Allee effect means that there is a minimum size for the self-reproducing solar plant factory that will allow it to be self-sustaining and long-lasting. Have we reached the "tipping point" leading to this condition? At present, it is impossible to say, but we cannot exclude that it has been reached or that it will be reached before the depletion of fossil fuels will bring the collapse of the current industrial system.

The next question is whether a self-sustaining stereosphere can coexist with the organic biosphere. According to Gause's law, well known in biology, two different species cannot coexist in the same ecological niche; normally one of the two must go extinct or be marginalized. Solid state and photosynthetic systems are in competition with each other for solar light. There follows that the stereosphere could replace the biosphere if the efficiency of solid state transduction systems were to turn out higher than that of photosynthetic systems. But this is not obvious. PV cells today appear to be more efficient than photosynthetic plants in terms of the fraction of solar energy processed but we need to consider the whole life cycle of the systems and, at present, a reliable assessment is difficult. We should take into account, anyway, that solid state creatures don't need liquid water, don't need oxygen, are not limited to local nutrients, and can exist in a much wider range of temperatures than biological ones. It means that the stereosphere can expand to areas forbidden to the biosphere: dry deserts, mountaintops, polar deserts, and more. Silicon based creatures are also scarcely affected by ionizing radiation, so they can survive in space without problems. These considerations suggest that the stereosphere may occupy areas and volumes where it is not in direct competition with the biosphere.

The characteristics of the stereosphere also allow it the capability of surviving catastrophes that may deeply damage the biosphere and that will eventually cause its extinction. For instance, the stereosphere could survive an abrupt climate change (although not a "Venus Catastrophe" of the kind reported by James Hansen). Over the long run, in any case, the earth's biosphere is destined to be sterilized by the increasing intensity of the solar irradiation over times of the order of a billion years. (and smaller for multicellular organisms). The stereosphere would not be affected by this effect and could continue existing for the five billion of years in which the sun will remain in the main sequence. Possibly, it could persist for much longer, even after the complex transformations that would lead the sun to become a white dwarf. A white dwarf could, actually power PV systems perhaps for a trillion years!

A more detailed set of considerations of mine on a related subject can be found in this article on "Biophysical Economics and Resource Quality, BERQ). 


Notes: 

1. I am not discussing here whether the possible emergence of the stereosphere is a good or a bad thing from the viewpoint of humankind. It could give us billions of years of prosperity or lead us to rapid extinction. It seems unlikely, anyway, that humans will choose whether they want to have it or not on the basis of rational arguments while they still have the power to decide something on the matter. 

2. The concept of a terrestrial metabolic system called the stereosphere is not equivalent, and probably not even similar, to the idea of the "technological singularity" which supposes a very fast increase of artificial intelligence. The "self-reproducing solar plant factory" needs not be more intelligent than a bacterium; it just needs to store a blueprint of itself and instructions about replication. Intelligence is not necessarily useful for survival, as humans may well discover to their chagrin in the near future.

3. About the possibility of a photovoltaic-powered Dyson sphere around a white dwarf, see this article by Ibrahim Semiz and Salim O˘gur.

4. The idea of "silicon-based life" was popularized perhaps for the first time by Stanley Weinbaum who proposed his "Pyramid Monster" in his short story "A Martian Odissey" published in 1933. Weinbaum's clumsy monster could not exist in the real universe, but it was a remarkable insight, nevertheless. 







Monday, August 7, 2017

Our Photovoltaic Future: The Metabolic Revolutions of the Earth's History.






Illustration from the recent paper by Olivia Judson on "Nature Ecology & Evolution (2017) "The Energy Expansions of Evolution". 


Olivia Judson published a very interesting paper this March on "Nature Ecology & Evolution". It is a wonderful cavalcade along 4 billion years of the history of the Earth, seeing it in terms of five "metabolic revolutions." It is an approach that goes in parallel with a paper that I wrote last year on BERQ; even though I focussed on the future rather than on the past. But my paper was very much along the same lines, noting how some of some of the major discontinuities in the Earth's geological record are caused by metabolic changes. That is, the Earth's changes as the life inhabiting it "learns" how to exploit the potential gradients offered by the environment: geochemical energy at the very beginning and, later on, solar energy.

Seen in these terms, the Earth system is a gigantic autocatalytic reaction that was ignited some four billion years ago, when the planet became cool enough to have liquid water on its surface. Since then, it has been flaring in a slow-motion explosion that has been going faster and faster for billions of years, until it is literally engulfing the whole planet, sending offshoots to other planets of the solar system and even outside it.

Judson correctly identifies the ability to control fire as the latest feature of this ongoing explosion. Fire is a characteristic ability of human beings and can be argued that it is the defining feature of the latest time subdivision of the planet's history: the Anthropocene.

Judson stops with fire, calling it "a source of energy" and proposing that "The technology of fire may also, perhaps, mark an inflection point for the Solar System and beyond. Spacecraft from Earth may, intentionally or not, take Earthly life to other celestial objects." Here, I think the paper goes somewhat astray. Calling fire a "source" of energy is not wrong, but we need to distinguish whether we intend fire as the combustion of wood, that humans have been using for more than a million years, and the combustion of fossil hydrocarbons, used only during the past few centuries. There is a big difference: wood fires could never take humans to contemplate the idea of expanding beyond their planetary boundaries. But fossil energy could fuel this expansion at most for a few centuries and this big fire is already on its way to exhaustion. If the Anthropocene is to be based on fossil fuels, it is destined to fade away rather rapidly.

Does this mean that we have reached the peak of the great metabolic cycle of planet Earth? Not necessarily so. Judson seems to miss in her paper that the next metabolic revolution has already started: it is called photovoltaic conversion and it is a way to transform solar energy into an electric potential, coupled with the capability of controlling the motion of electrons in solid state conductors. It is a big step beyond fire and thermal machinery (*). It is, by all means, a new form of metabolism (**) and it is generating a new ecology of silicon-based life-forms, as I discussed in a previous post that I titled "Five Billion Years of Photovoltaic Energy". 

So, we are living in interesting times, something that we could take as a curse. But it is not a choice that we are facing: we are entering a new era, not necessarily a good thing for humans, but most likely an unavoidable change; whether we like it or not may be of little importance. It is a new discontinuity in the billion years long history of planet Earth that will lead to an increased capability of capturing and dissipating the energy coming from the sun.

The great chemical reaction is still flaring up and its expansion is going to take us somewhere far away, even though, at present, we can't say where. 


A new lifeform, just appeared in the Earth's ecosystem:









(*) The Jews have been arguing for about a century whether electricity has to be considered a form of fire and therefore prohibited during the Sabbath. It is surely an interesting theological discussion, but for what we are considering here there is no doubt that fire (a hot plasma ignited in air) is not the same as electricity (controlled movement of electrons in solids)

(**) The supporters of nuclear energy may argue that the next metabolic revolution should be seen as the production of energy from nuclear fission or fusion. The problem is that the resources of fissionable material in the whole solar system are too small that they could hardly fuel a truly new geological epoch. As for fusion, we haven't found a technology able to control it in such a way to make it an earth-based source of energy and it may very well be that such a technology doesn't exist. But, on the sun, fusion works very well, so why bother?



Friday, August 4, 2017

Does Propaganda Still Work? Donald Trump and Russiagate




Image above, from the Washington Post, 17 July 2017. Donald Trump seems to have been basically unaffected by the Russiagate campaign, even with those who disapprove him. Is it a sign that propaganda doesn't work anymore as it used to in the past?



It has been said that the best trick of the devil is to convince you that he doesn't exist. The same holds for propaganda, which draws most of its power from being able to convince people that it doesn't exist. Yet, it exists and its impact on people's lives has been gigantic. The more we try to ignore it, the more it affects us, especially those of us who claim to be immune from it.

Yet, it would seem that propaganda can work only when it can eliminate or marginalize the opposing voices in environments. Maybe the concept of "free press" is a little optimistic today in the Western World. Still, with the availability of the Internet, everyone can verify the media statements and there is no lack of opposing voices in the galaxy of the social media and the various independent media sites. That had led someone to prophesize "The end of Spin".

Can it be that propaganda has been weakened by the Web? Difficult to say, but some examples indicate that something has changed. A good example is the attack on Russia. It was done literally by the book, applying all the recipes that are known to work and have worked beautifully well in the past. In particular, it was based on demonizing the bad guy of the moment, Vladimir ("Vlad") Putin, accused to be a bloodthirsty dictator and compared to, well, you guess whom! The real objective, however, soon became to use the already done demonizing work to bring down the hated Donald Trump, accused over and over of connivance with the evil Russians,

Did it work? In short, no. At least for what it was its main purpose, that of bringing down Donald Trump, it was an abject failure. Despite the daily hammering of all sort of accusations about Trump being Putin's straw man, the idea just didn't stick. Even with those who disapprove Trump as president, the idea that he is somehow connected to, or working for, Russia and Putin ranks very low among the criticism list.

But that doesn't mean that the anti-Russian propaganda didn't work. Here are some recent Gallup poll results:


The barrage of anti-Russian news on the mainstream media has clearly had some effect, bringing 70% of Americans to have an unfavorable opinion of Russia. So, propaganda still works, it seems.

Yes, but only within some limits. If we compare these data with those for Iraq, we find that in 2003, 93% of Americans (!!) declared to have an unfavorable opinion of Iraq. That was a true triumph of modern propaganda that could obtain this result on the basis of a complete fabrication: that of the "weapons of mass destruction" allegedly deployed in Iraq. Such an extreme view of Russia seems unlikely to be attainable today.

So, could it be true that propaganda doesn't work anymore so well and so smoothly as it did in the past? Or is it Trump the maverick who is disrupting everything? The only thing we can say is that propaganda may have weakened a little, but it is still the formidable weapon it has been from the time when it was developed in its modern form by people such as George Creel and Edward Bernays.

Yet, in the long run, even the most wondrous contraptions are subjected to the Seneca Collapse. And one of the reasons why empires collapse is because of the mountains of lies that the elites tell to their subjects. It has happened in the past, it may happen again. It probably will.






Wednesday, August 2, 2017

The stoic viewpoint: make the best of what's in our power and we take the rest as it naturally happens.


 The Stoics are the people on the top of the hill. They are applying Epictetus' maxim that says "What, then, is to be done? To make the best of what is in our power, and take the rest as it naturally happens." (Discourses, 1.1.17). 
(Image courtesy: Nate Hagens.)


There comes a point in which you have to acknowledge reality: Business as usual, BAU, is dead. Not that it would be impossible to avoid, or at least soften, the imminent disruption of our way of life caused either by resource depletion or climate change (or both). But that implies making sacrifices, renouncing something today for a better world tomorrow. And people are just not going to do that. We are not wired to plan for the future. We are wired to exploit what we have at hand.

The recent global events have shown that humans, worldwide, are unable to see priorities. The richest country in the world, the US, has turned its back to what science says about our faltering ecosystem, pursuing the impossible dream to return to an imaginary world of happy coal miners as England was at the time of Charles Dickens. The US is not the only example of a society that desperately tries cling to the old ways, refusing to change. Practically every country in the world is pursuing a dream of economic growth which, at this point, is just as impossible as a return to coal.

Does that mean we have to fall into despair? Some people seem to have arrived at this conclusion: there is nothing that can be done, therefore nothing that should be done. After all, what was so bad with the Middle Ages? And, anyway, human extinction would surely solve a lot of problems. Other take the opposite view, desperately hoping for some technological miracle that will lead us to leave the earth, colonize other planets, and mine the inexistent ores on asteroids.

What is to be done, then? Over the years, I found myself closer and closer to that group of ancient philosophers who lived during the times of decline of the Roman Empire who called themselves "Stoics" and who themselves the same question: what's to be done? The answer was given by Epictetus in his "Discourses:" It is "To make the best of what is in our power, and take the rest as it naturally happens". (1.1.17). And, after all, Seneca, to whom I credit the idea of the "Seneca Cliff", was a stoic, too!

So, here is a picture of the vegetable gardens that we planted in the courtyard of a building of the University of Florence (here it is shown with two students who have volunteered to take care of it). We plan to plant many more of these gardens. And, in this way, we make the best of what's in our power and we'll take the rest as it naturally happens.







Who

Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014). His most recent book is "The Seneca Effect" to be published by Springer in mid 2017