Monday, May 28, 2012

Leverage points in energy storage.

This is a written version of a lecture that I gave to my students of the class of "Advanced Materials Technology." In this case, the subject of the lecture, energy storage, led me to develop some considerations that had to do with politics and with the typical human way of taking so often the wrong decision. I am not sure that there is a thermodynamic reason at the basis of this tendency, but this post gives some hint that it may be the case. The image of the waterfall above is used to indicate the flow resulting from an energy potential.

Hello, everyone, and welcome. Today, I would start by telling you of something that happened to me yesterday. I was giving a presentation on energy at a public meeting and several of the people attending were politically minded. During the debate, someone said something like, "You see, professor, I think if you were to be a candidate for the next elections, you would get exactly zero votes".

Let me say that it wasn't intended as an offense. No; it was a statement of fact and it  was correct. So, what did I say that made me so completely unelectable? Well, I had said that natural resources are limited, so that we should strive to consume less resources, not more. But, of course, you just can't run for a public office on a platform like that! There is something, I think, that makes impossible to connect physical reality with politics and that's why sometimes I have the impression that politics is the art of always taking the wrong decision.

Of course, politics is not the subject of our class, but I thought to mention to you the debate of yesterday because it think it is important to frame problems in a broad way; otherwise we might find ourselves in a situation where we spend a lot of effort and money to develop sophisticated technologies to solve the wrong problem. I think that is a very common situation, much more common than I would like it to be. And it may also be the case of energy storage. A lot of money and effort is spent in order to find technological solutions for storing the energy produced by renewables, but very little to understand what the real problem is. How much energy storage do we really need? And is it true that if we don't have 100% energy storage then renewables are useless, as some people say?

On this subject, I would like to start by mentioning something that was said some decades ago by Jay Forrester, the developer of system dynamics. He said that all complex systems have something that he called "leverage points;" that is, points on which you can act to control the system while expending very little effort. He added another concept: that people normally understand very clearly where the "levers" of the system are, but they often tend to pull the levers in the wrong direction; worsening the problem rather than solving it. Forrester's idea has been popularized by a rather famous paper by Donella Meadows titled "Leverage Points." It is a very interesting paper, highly suggested for you to read. But, today, we'll focus our discussion on energy storage. 

You surely remember from our previous lessons that system dynamics a curious way of drawing rectangles and little arrows. So, when we draw a rectangle we intend it as a "stock", an amount of something. Then, let me draw one on the white board.
This box represents a stock of resources and I marked it with the letter "R". Now, with "resources" we can mean anything, from money in your pocket to grain in a barn. The interesting thing, however, is when we intend these resources as energy.  So, we can call this box as stored energy.

You can think of this stored energy as, for example, a tank of gasoline. As long as this energy stays locked inside the tank, it doesn't do anything for us. In order for energy to be useful for something, we must use it and in order to use it we must have this energy flowing; to run an engine we must burn gasoline. That's very general and it is here that the laws of thermodynamics come into play. We know that energy must be conserved and also that it must be degraded. So, let me modify the diagram to make it show that energy flows. I'll do that by drawing some arrows and little clouds.

Let me explain. You see that there is a double edged arrow that goes from the "resources" box to a little cloud, at the bottom. We assume that the box has a higher thermodynamic potential than the cloud (which is another stock, just we don't bother to measure its size). So, energy flows from the box to the cloud and is degraded in the process. It could be gasoline being burned, water flowing downhill from a reservoir, and similar things. 

The downhill flow of energy is regulated by a valve represented by the butterfly-like thing in the drawing.  You can open and close the valve and this is represented in the model by changing the values of the constant "K1". That will regulate the flow, but that's not the only factor. Also the size of the reservoir will have an effect on the potential and hence on the flow. If you are drawing water from the bottom of a container, the speed of the flow will depend on how much water there is in the container. As you draw water out, the flow will gradually diminish. This is a common effect also for other types of systems, although not always. If we were thinking, instead, of a tank of gasoline then, obviously, the engine wouldn't slow down as there is less gas left!

I have also added another feature to the model: a way to fill the reservoir. Here we have another flow rate regulated by a valve. The energy flows into the reservoir from another stock, at a higher potential. Also this stock is represented as a little cloud - meaning that we don't care about its size. Here, I assume that there is no effect of the size of the stock on the rate of flow (think of rain filling a water reservoir) which is regulated simply by a constant called K0. So, we built a very schematic model of what we mean as energy storage.

Of course, when we go into the details, we see that the actual physical characteristics of the storage and of the valve will vary depending on the kind of system we have. Imagine you have a charge stored inside a capacitor (or maybe a battery). Then, you can you can regulate the flow of current by means of a variable resistor. If the resistor obeys Ohm's law, then the flow (the current) is directly proportional to the potential (the voltage). In the case of automotive batteries, a lot of effort is made to make sure that the potential remains constant as the battery discharges. This makes the system behave very differently than a dam, but it makes sure that your electric car keeps going with the same power available all the time. Otherwise, it would be like a big clockwork toy car, slowing down as it moves.

Whatever the details of the system could be, the point is that the energy cost related to controlling the valve is often very small in comparison to the amount of energy that can be stored in the system. So, you have this power of controlling the system potentials. Of course, you need to have the right technology, the equipment, the engineering and more. But once you have this capability - and often it is not that difficult - then controlling the flow becomes a decision that can be taken independently of thermodynamics. I think that now we can understand what Forrester had in mind with his "leverage points". The thermodynamic parameters of the system cannot be easily changed but large stocks of energy can be controlled by a relatively minuscule valve, such as the duct of a dam or the control rods in a nuclear reactor. It is a lot of power that you can have on these systems.

But, then, what does it mean what Forrester said, "pulling the levers in the wrong direction?" Well, this is the interesting part. Let's go back to the simple stock and flow model that we made before. Let's think of stored energy, this time, in terms of crude oil stored underground - in its natural deposits. Now, you know what most politicians say in this respect. They say that we should invest into increasing the production of national oil resources. They say that in this way we'll create jobs, restart economic growth and all the rest. But, in terms of a stock and flow diagram, what does it mean exactly? Well, something like this:

"R" is now oil fields. Obviously, there is no "rate0," that is there is no oil coming into the stock, since oil was created millions of years ago and no political activity will affect events that took place during the Jurassic. So, what has been happening is that, as we have been extracting (or producing, if you like) oil, the amount of oil remaining underground is going down. That has changed the "potential" of the wells. The amount of energy that you can get from a barrel of oil has not changed, but the total energy that you can get from the system is smaller, since it takes now more energy to extract the same amount of oil. This change of the thermodynamic parameters of the system appears in the form of economic parameters. It takes more and more money to get oil out, and that tends to reduce the flow marked as "rate1". We are crossing here the concept of "peak oil" but let's not go into the details right now.

Back to Jay Forrester, most people are perfectly able to understand where the "levers" are and our politicians are no exception. They say that we should act on the valve in the diagram. We should increase the coefficient K1 in order to compensate for the tendency of the system or slowing down its production rate. That's surely possible by means of investments, technology, and other things. But you understand that it is a mistake, don't you? By increasing the production rate we are running out of oil faster! It is what I called the "Seneca Effect" in a post where I took inspiration from the ancient Roman philosopher, Seneca, when he says that ruin is much faster than fortune. By pushing for extracting more oil from the remaining reserves we could perhaps enjoy a brief glut of oil, but then we would see it run out much faster than the "natural" rate of the depletion of the reserves. Unfortunately, it seems that not many politicians read my posts, alas....

So, you may understand why yesterday at that meeting I was told that I would get zero votes as a candidate for the next elections. See? Proposing to produce less oil means to increase gas prices and that's never very popular in a political context. I think it wouldn't be so unpopular as, say, proposing to abolish soccer, here in Italy. But it would surely come close.

That illustrates the mistake which comes from opening the valve too much. Of course, people can do the opposite mistake, even though this case is a bit more subtle. Let's go back to the case of a dam. If you don't let water flow, that is, you keep the valve closed, then, eventually the dam will overflow. You can see this as the "valve" behaving in a non linear way - having a threshold. Even worse, if there is too much potential in the basin, the dam may give way and that's another kind of threshold for the valve; a very bad one, of course. There are other examples; for instance, at the time of steam engines, people tended to increase the pressure in the water boiler by acting on the regulating valves. That gave them more power, surely, but, sometimes, the whole thing blew up. Think of controlling a nuclear reactor and you have exactly the same problem. It is what happened with the Chernobyl disaster. People had the means of controlling the flow of energy created by the reactor but they let too much potential accumulate. When they rushed in to stop the reactor, it was too late. So, the point is that whenever you have an energy potential, if you let it accumulate, it will try to release, or "vent" this potential in ways that may have nothing to do with a lever (or a valve) that you can control. A lot of accidents occur because of this effect. bad.

A typical phenomenon, here, is that even though you may think that you are in control; that is your "lever" works well, you will not be able to manage the system the way you would like to. If there are time delays in the system, humans will have a hard time in understanding it and the result will be wide oscillations; extremely difficult to control and which can cause a lot of damage. This phenomenon has been studied by - guess by whom!  - Jay Forrester who dubbed it the "bullwhip effect." It is normally applied to business systems, but even business systems must obey the laws of thermodynamics. Systems can oscillate and collapse even without human intervention. This is the case of the so-called "self organized criticality". You may have heard of it in terms of the "sandpile model". It is a different kind of model, but the avalanches in the sandpile are, in the end, caused by the gravitational potential acting on the grains.

So, I think we got to the point I wanted to make with this presentation. Levers or valves are ways to create potentials and let them accumulate. It is good to have such valves, but we have to be very careful with what we do. Sometimes we squander the accumulated potential and sometime we may create high potentials which then we can't control so well. The results may be uncontrollable oscillations.

Now, let's go back to the problem we had started with: energy storage for renewables. What people often say in this case - especially politicians - is that we should build a big energy storage system that would allow us to have energy "on demand" whenever we want it. But, because it would be so expensive, the problem is often considered as the definitive reason why renewables will never be of any use.

But let's analyze the question more in depth. Energy "on demand" means that we want stable prices and full availability at any time. But storage, in itself, is not a guarantee of stability. Consider crude oil: there is no problem in storing it; surely we don't have the problem of having to use it before it disappears - as it is the case with wind or sunlight. But oil prices fluctuate a lot nevertheless; as we all know. We attribute what we call "price volatility" to market factors. But we can also see it as a manifestation of the "bullwhip effect" that Forrester described long ago. So, storage doesn't, in itself, guarantee price stability - on the contrary it may well increase the amplitude of fluctuations!

Let me explain. If there is little storage space available producers must reduce prices to sell the energy they produce before they have to throw it away. It is exactly the opposite when producers have lots of storage space. With oil safely stored inside wells, producers may be tempted to keep it there and wait for customers to become desperate and willing to pay any price for it. I am afraid that something like that may have been happening more than once in the world's oil market. That may become more and more frequent as producers understand that their resources are gradually running out.

So, Forrester's idea turns out to be correct once more. In calling for more and more storage for renewable energy, we are pulling the levers in the wrong direction. If we want to reduce price volatility we should do exactly the opposite; we should reduce storage instead of increasing it. Of course, don't make me say that we don't need storage at all. We do need energy on demand for many practical purposes and for essential services, say for hospitals and the like. We need to be able to turn lights on even in a windless night. What we don't really need is a system that aims to provide energy at any moment, at constant prices. It would be atrociously expensive and we would have big troubles in keeping it stable.

Instead, the best compromise in terms of cost would be a system with limited storage that uses prices as a way to manage demand. With such a system you can have as much energy as you want, at any moment, but you must be prepared to pay for it. That may be seen as a problem, but also as an opportunity. You may have to pay a lot for energy at some moments, but you may also have it very cheap in other periods  - that's an opportunity if you can be flexible. It is a little like with air travel. If you are flexible about your schedule, you can travel at low costs. Otherwise, you must be prepared to pay a lot of money for your ticket. By the way, these techniques of "demand management" used by the airline industry give the possibility of traveling even to people who, otherwise, couldn't even dream to afford a plane ticket. In a sense, in such a system the rich are subsidizing the ticket of the poor. Something similar could happen for energy in the future - limiting the amount of storage could make energy more affordable even for the poor.

So, you see that the lack of a complete storage system is not the death sentence for renewables. Instead, it is a feature that allows for a better distribution of low cost energy. Incidentally, it works the same also for nuclear energy. Nuclear plants are not storing energy; normally they are running at near full power all the time. That doesn't match the market demand as it is nowadays and that means there are moments - overnight for instance - when you can have lots of energy at low prices from nuclear plants. Unfortunately, nuclear plants have plenty of different problems, as we all know.

I wanted to conclude this talk with some even more general considerations about the whole economic system. We can see the economy as a machine that stores energy in the form of "capital" and gradually releases it in the form of waste (or "pollution" if you like). The interesting point is that here, too, Forrester's law applies; that is, we tend to pull the levers in the wrong direction. One of these wrong ways would be opening up too much the valve that connects the capital stock to the waste stock. It is what we call "consumerism." Of course, consuming something means to destroy it and I have this feeling that maybe we are doing that really too fast, don't you agree with me?  That's surely a problem. The other possible way to operate the valve in the wrong way is that sometimes we accumulate so much capital  - that is, so much potential - that we lose control of how it is dissipated. We may pass some threshold that makes dissipation very fast, actually disastrously fast. We call this kind of phenomenon "war," which is, by the way, another example of how politics normally manages so often to take the wrong decisions.

So, you see that there is something as too much storage and I think that you are gaining some idea of how system dynamics coupled with thermodynamics gives to you a wide ranging view of many kinds of phenomena; most of them very relevant for our life. Now, of course this class is not about economics and in the next lesson we'll go in more detail into the technology of energy storage; batteries, fuel cells and the like. But I thought that this introduction could be useful for you and I hope that it clarified, at least, that knowing about thermodynamics will not very helpful for your future political career, in case you were planning one!

Monday, May 21, 2012

The great chemical reaction: life and death of Gaia

 "This text is a written version of a talk that I gave in Desio (near Milano, Italy) at a meeting organized by the Centro Culturale Lazzati on Jan 30th 2012. It is much shortened with respect to the actual talk, but it tries to maintain the spirit and the rhythm of that presentation. 

You know, ladies and gentlemen, every time I give a talk I try to say  something different - otherwise it would be boring for me and, perhaps, for you, too. So, this time I thought I could do something closer to what's my job. After all, I teach chemistry. So, shouldn't I teach you a little bit of chemistry? Then, I thought that I could start by presenting to you a chemical reaction. Here it is:

Well, after you give speeches for a while, you become somewhat telepathic. So, I know what you are thinking. Yes: I can read your minds and I know that this slide is making you happy; isn't it? By the way,  the exit door is down there. Maybe you can scream something like "I forgot to turn off the gas stove!" as you run away.

Well, nobody is running away and that's nice. I said that I know what you are thinking and it is true - without exaggerating, of course! You are thinking that chemical reactions are boring. And I agree with you: chemical reactions are very boring. I can tell you that: I studied chemistry, I teach chemistry, I've been working in chemistry for all my life. I should know!

So, why do chemists like the things that they hate - so to say? Are they masochist or what? Well, no. Maybe I am asking you to believe something a little too extreme, but let me tell you something: chemistry is not boring! Chemistry is fascinating, it is interesting, it is even fun. And chemical reactions are not what chemistry is about. Chemical reactions are just a shorthand that hides the really interesting things. If you look at the symbols, well, it is boring. If you look at what the symbols describe, if you look inside, well it is not the same. It may be an interesting story, as I was saying it may be fun, it may be fascinating. You know, when I was a freshman in chemistry, I had to attend chemistry labs. There were many nice girls in my class and they were all wearing lab coats in the lab - not exactly sexy as garments. But that was just the outside: what was fascinating was the inside!

So, I hope today that I could show you that the specific reaction that I am showing to you today is hiding something hugely interesting. It is called "silicate weathering" and is the basis of life on Earth. The way I have written it, it is very simplified - it is much more complex than that. But we can take it in this form in order to understand it. If that reaction were not running all the time on our planet, I wouldn't be here, you wouldn't be here and not even those nice looking girls that I met during my time as a student would ever have existed. Nothing alive on this planet would exist. The entity we call "Gaia" would not exist.

Let me explain. What do we mean exactly with "Gaia"? I think the best I can do is to show you an image.

I am sure you recognize what this is; it is "Pandora" from the film "Avatar." Now, we can say that Pandora is a sort of an Earth on steroids. It is lush, it is full of life, full of creatures: dragons, monsters, waterfalls, trees, mountains, clouds; all that. Of course, Pandora is a fantasy world; but we are discovering plenty of new words in the Galaxy; many are about the same size of our Earth and at the right distance from their suns; so they could well host organic life similar to ours - like Pandora does in the Avatar movie. We can't say for sure if such words exist, but one thing we can say is that - if they exist - the reaction I was showing to you before must be running on there. A world without that silicate weathering reaction running is like Mars or Venus. No silicate weathering reaction, no life.

Let me explain: in order for life to exist, there have to be some materials that make it exist. And the most important material that makes life exist is a special molecule that we call carbon dioxide and that we write as CO2, pronounced see-oh-two. You know that carbon dioxide is what plants use to carry on photosynthesis, which is what keeps alive everything on this planet. If Pandora is so lush and beautiful, it has to have CO2 in the atmosphere, just as our Earth does. Plants make CO2 react with hydrogen extracted from water and out of this reaction they create all organic matter which is then be used to make living beings. In a sense, CO2 is Gaia's food, it is also Gaia's blood, Gaia's lymph and more.

But, then, if CO2 is Gaia's food, there is a problem. CO2 is a reactive molecule and here is where the reaction I wrote kicks in:

You see that this reaction contains carbon dioxide; CO2, on the left side. And you see that this CO2 reacts with something written as "CaSiO3" which I can read as "calcium silicate". Now, the reaction (keep in mind that it is very simplified) says that carbon dioxide reacts with the silicates of the crust to create carbonates (CaCO3) and silica (SiO2). So, a gas, carbon dioxide, reacts with rocks to create more rocks - those carbonates are what we commonly call "limestone". So the carbon which once formed CO2 becomes carbonate, which is solid. Let me show you:

This is a weathered rock somewhere. See? CO2 reacts with the rock and corrodes it. In doing so, CO2 disappears. Clearly, it is a very slow process. You don't see rocks being washed away by rain, unless you are willing to wait for a very, very long time. How long? Well, we are talking of geological times; millions of years, but that's not what we are worried about. The question is; if CO2 is consumed by the reaction, how long would it take for the atmosphere to lose all of it? (and note that plants would start dying much before CO2 were to disappear completely).

On this point, there is an answer that you can find in Robert Berner's 2001 book which has a rather impressive title "The carbon cycle of the phanerozoic". Berner says that all the CO2 in the Earth's atmosphere would be consumed by the weathering reaction in about ten thousand years. In part, it would be replaced by CO2 degassing from the oceans, but even that source would be exhausted in about 300,000 years. These numbers are, of course, just orders of magnitude but for what we are concerned here, the uncertainty doesn't matter much. Life on Earth has been going on for more than three billion years and there must have been CO2 in the atmosphere all this time. No CO2, no life. There is no escape to that. So, CO2 was not consumed by the weathering reaction, nor by the formation of fossil fuels and coal, which also removes it from the atmosphere.

So, you see that we arrived to a paradox. The weathering reaction should have consumed all the CO2 in the atmosphere long ago but there is still plenty of it; enough, at least, to keep photosynthesis going and with it all life on Earth. But paradoxes are almost always pathways to understanding deeper truths and this one is no exception. Let's go back (once more!) to the weathering reaction:


You probably remember from what you studied in high school that chemical reactions never go fully in one direction. They can go both ways and often they are in an equilibrium condition in which reactants and products remain in constant concentrations. And you may remember that there are conditions that can shift the equilibrium from one direction to another. About the weathering reaction, we said that it goes from left to right, as you can see from the picture of the weathered rock seen before. But, if we could make the reaction go from right to left, then the carbonates (limestone) decompose and become a source of CO2. If that were possible, we'd have a way to bring CO2 back in the atmosphere. We need, therefore, to close the "geological cycle" of CO2 (something different than the well known biological cycle - that wouldn't be enough by itself to keep CO2 in the atmosphere).

How could that happen? Well, another thing that you surely learned in high school is that the equilibrium of a chemical reaction depends on temperature. There are good reasons based on thermodynamics that say that a solid compound decomposes at high temperatures. That's what happens to carbonates, provided that you can reach temperatures of the order of several hundred degrees Celsius - possibly over a thousand. Now, where can you find these temperatures on Earth?

Very easy: look at your feet. Think of making a hole of a few tens of kilometers and there you are. You find an area of the Earth called the "mantle" which is semi-molten rock composed mainly of  silicates, but also carbonates. Here is the structure of the inside of our planet as we know it today.

You have to go deep down, but eventually you reach temperatures where carbonates are decomposed into CO2 that would then be degassed out by volcanoes, geysers, hot springs, all that. That's exactly what happens in the great CO2 cycle that goes under the name of "plate tectonics". Here is it:

Let me explain a little this image. It shows how the ocean floor moves and is gradually pushed inside the depths of the Earth in a process called "subduction". Everything that stands on the ocean floor is destined, eventually, to disappear into the mantle. But this is also a cycle, you can see in the figure how material from the mantle is pushed up to the surface to form new ocean floor at those regions which are called "mid-ocean ridges". A very slow process, it takes tens of millions of years for a piece of rock that surfaces at the mid ocean ridge to go back to the mantle. But it does occur.

Now, this is also the CO2 cycle. You see, we said that the reaction of carbon dioxides with silicates produces carbonates. These carbonates end up on the ocean floor, often in the form of the shells of dead marine organisms. And the final result is that this carbonate is pushed into the mantle - where it is hot enough to decompose it into oxide and CO2. Then, the CO2 returns to the atmosphere in the form of volcanic eruptions.

The beautiful thing of all this is that the cycle is that it is the "control knob" of the Earth's surface temperature. Really, the CO2 cycle is a thermostat that keeps the Earth not too warm and not too cold; just right. It has been doing that for billions of years. As a thermostat, it must be said that it has not always functioned so well: we have had ice ages and those hot periods called sometimes "planetary hothouses". But, on the whole, the Earth's temperature has always remained within the limits that make life possible. Otherwise, we won't be here.

So, how does the thermostat work?  First of all, you know that CO2 is a "greenhouse gas". It traps the heat emitted by the Earth's surface acting a little like a blanket that keeps the planet warm. So, the more CO2 there is, the more we expect the Earth to be warm. As a consequence, the temperature can be regulated by controlling the concentration of CO2 in the atmosphere. But how can that be done? Well, there is the trick: the speed of chemical reactions depends on temperature. It is true also for the silicate weathering reaction:

High temperatures make the reaction go faster. So, if the Earth's becomes warmer, then there is more CO2 consumed and that reduces the temperature because the concentration of CO2 goes down - and remember that it is a greenhouse gas! The opposite takes place if the Earth becomes cooler - the reaction slows down, the CO2 concentration increases because of all those volcanoes emit it and, in the end, the temperature returns to the previous values. See? Simple and effective.

Of course, as I said, the control is far from perfect. It involves times of the order of millions of years, so it takes a huge time lapse for the planet to recover from a perturbation. For instance, a very large volcanic eruption took place some 250 million years ago in Siberia. It emitted so much CO2 that the resulting increase in temperatures almost killed all life on Earth. The silicate weathering reaction, eventually, absorbed all that CO2 and brought temperatures back to more acceptable values for the biosphere. But it took millions of years. So, if we look at the temperature record, we see that it oscillates and that shouldn't surprise us too much. Here are the data we have for the past 550 million years or so, the period we call "Phanerozoic":

As I said, the regulation is not perfect, but the fact that temperatures oscillate around a constant value tells us that there is a regulation ongoing. You see, the point is that the planet badly needs that regulation, because the sun's irradiation is far from being constant. It increases of about 10% every billion years because of reasons that have to do with the evolution of stars. So, in a period of half a billion years, as the Phanerozoic, we'd expect the planetary temperature to go up as the result of the sun becoming more and more bright. Instead, we don't see it. What we see, instead, is a gradual reduction of the concentration of CO2, as we see here (these data are, again, from the work of Berner):

Yes, it is irregular, but there is no doubt that the concentration of CO2 has gone down, on the average, during the past half billion years. And if we make a little calculation that takes into account the increase in solar luminosity (you can find it in Berner's book) we can see that the numbers do click together. The variation of CO2 concentration is what has kept the Earth not too warm and not too cold, just right, during the geological past.

Now, I guess you are asking yourselves what's going to happen in the future. As you surely noted, the CO2 concentration has been going down and continues to do so (apart from human intervention in terms of burning fossil fuels, but that's not part of the regulation system). Something that could happen is that the Earth's core cools down so much that it will stop the tectonic movement that decomposes the carbonates and closes the CO2 cycle. In that case, the CO2 concentration would go to zero and kill the biosphere. But, according to the data we have, that will not be the cause of the death of the biosphere which, instead, will be destroyed by the increasing solar irradation. Eventually, we'll arrive to a point where the system can't reduce the concentration any more. Yes, and before we arrive to that point, there won't be enough CO2 for plant photosynthesis. And without photosynthesis, there can't be any life on Earth - everything must die.

That's indeed the ultimate destiny of the Earth's biosphere. Of Gaia, if you like. If Gaia is a living being then, as all living beings, it must die. It will be a slow process - very slow by human standards. But it is going to happen. In the simulation below, by Franck and others, you can see the slow winding down of the biosphere which should become extinct a billion and a half years from now. You see also that vertebrates should disappear much earlier, perhaps in less than a billion years

And here is an image of the ultimate destiny of the Earth. To be sterilized by the sun as it becomes more and more bright. The oceans will evaporate and - eventually - the surface will melt under the tremendous heat.

That is, clearly, a far away future. Maybe, by then, our descendants, if there will be any, will have found another place to live, around another star or somewhere in the galaxy. But our main concerns are not about such a remote future. Our main concern is that even the near future may give to our close descendants, a lot of problems with the Earth's temperature.

The problem is that we have been tinkering with the thermostat without understanding exactly what we were doing. And we have been emitting into the atmosphere a large amount of gases which had been removed from the atmosphere as part of the regulating mechanism. Gases which had been stored underground in the form of what we call "fossil fuels": coal, oil, and natural gas. The perturbation made to the system is very large and extremely rapid if compared with anything that has occurred in the past history of Earth.

You probably have seen this picture and it is very, very worrisome. The fact is that such high CO2 concentrations have never occurred on Earth during the past few millions of years. When we had such concentrations, tens or hundreds of millions of years ago, the sun was less hot than it is now and, nevertheless, the Earth was a much warmer place than it is today. We might be able to adapt to a much warmer planet, but the process wouldn't be painless. Just think that the melting of the continental icecaps would submerge all of our coastal cities.

We can't hope that the silicate thermostat will save us from CO2 caused warming. This reaction


is damn slow by our standards. It will, eventually, remove from the atmosphere the CO2 we have emitted, but it will take tens of thousands of years, at the very least. Look at these simulations by Dave Archer and you see what the problem is:

See? part of the CO2 we have emitted in the atmosphere will still be there in 40,000 years from now. Actually, it will stay there much longer. So, you see how important it is the reaction that I showed to you. The silicate weathering reaction is what keeps "Gaia" alive - better said, it is Gaia. And don't make the mistake of thinking that Gaia is a goddess and that, somehow, she cares about us. No, it is more correct to say that Gaia doesn't give a damn about us - which is what you'd expect from a chemical reaction, after all. It is us who have been tampering with this chemical reaction and it will be us who will have to face the consequences.

In the end, we can't hope to force the planet to do what we want it to do. So, we must learn to live with the flow of the Earth's cycles. For that, we must know a little chemistry my idea today was to show to you a bit of this chemistry. But more than chemistry, we must learn our limits, otherwise we won't survive for long.

This is our Earth, not a fantasy planet, let's try to keep it the way we found it:

Sunday, May 13, 2012

Italy: chimeras of cold fusion

From the time when our ancestors cast the statue known as the "Chimera of Arezzo", Italy has been a country of chimeras. That's true especially in science, as shown by our minister for scientific research, Ms. Mariastella Gelmini, who produced a press release mentioning a "neutrino tunnel" that connected Italy directly to Switzerland - a true chimera if ever there was one. Then, the Italian story of "Cold Fusion" has been even worse, with Mr. Andrea Rossi claiming to have attained miraculous results in energy production with the device he called "E-Cat." Mr. Rossi's story collapsed when he himself admitted that there was nothing nuclear inside his device and that his "E-Cat factory", described as able to produce millions of pieces per year, was nowhere to be found on this planet (read the details here). But Rossi's disappearance from the scene was not the end of desktop nuclear energy in Italy. There are even weirder things going on, for instance, in the field called "piezonuclear energy". In the following, you can read the summary of a report on this matter which appeared on May 13 2012 on a major Italian financial newspaper. It is  written by Sylvie Coyaud, also known for her blog where she writes with the nick of "Ocasapiens". "Piezopolis" is a fascinating story that involves money and politics; a true thriller as Coyaud defines it. Chimeras in Italy, apparently, never end. 

Piezopolis, Italian-style thriller

by Sylvie Coyaud

For reasons of copyright, what follows is not a translation but a summary of Sylvie Coyaud's feature which appeared in the Italian financial newspaper  Ilsole24ore on May 13 2012. I have added a few comments in order to make this text clearer for the non-Italian reader. Thanks to Sylvie for her permission to publish this text and for her comments and suggestions (Ugo Bardi).

On May 4th in Turin, Alberto Carpinteri, of the Turin Polytechnic and chairman of the National Institute of Metrology (INRIM) organized a meeting, sponsored by Piedmont’s Regional Government, Ansaldo Nucleare, and the Catholic association "Solidarity and Development".  He presented a new form of energy “destined to change the global landscape of science and energy”, according to a local newspaper. In a research paper published in 2009 by Professor Fabio Cardone, Roberto Mignani and Andrea Petrucci, of the University of Rome-Tor Vergata, it was reported that thorium dissolved in water and subjected to pressure waves modifies its natural rate of decay and produced some neutrons. Professor Cardone and Alberto Carpinteri also claimed to have produced many more neutrons by fracturing pieces of granite ("piezonuclear fission").

In the near future, thanks to a patent requested by prof. Cardone, Startec – a company based in Brugherio (Milan) - will build reactors similar to the one made in 2005 "under the direction of col. Antonio Aracu", which will solve Italy’s economic crisis and the world’s energy crisis. To test the device, Abruzzo’s Regional Government granted Prof. Cardone the military site of Mount San Cosimo, where he will run a new research center on the transmutation of nuclear waste into clean energy.

Still missing is the financial support that the national government had allocated to such transmutations in 2009 thanks to the intervention of Sabatino Aracu, a member of Parliament (and the colonel’s brother). According to a leaked document, about 800 million euros will be needed to build prototype reactors over ten years, some 100-200 millions to equip San Cosimo and more money for further research. The purpose of the Turin meeting was to obtain these funds by means of “new alliances", said Francesco Mazzuca, commissioner of Sogin, a public company in charge of  decommissioning nuclear plants and disposing of nuclear waste. For the latter, there is now a solution: Prof. Cardone’s reactor.

In an open letter, Prof. Cardone claims "the discovery of a theory and of its phenomenon, both astonishing and shocking.... <which has> received the official recognition of publications and patents ... and is well known to all the scientists in the world who have been seeing for years that same discovery and testified its validity in international journals, with papers in accordance with scientific standards.

Since 2007, Cardone's "theory of the deformed space-time," a daring alternative to Einstein's relativity, remains firmly ignored in the literature. As to "its phenomenon", it has been immediately criticized by four physicists of Uppsala University who found "serious errors" in Cardone's data and measurements. In Canada, three more physicists replicated the experiment, and their “results and findings were in conflict with those reported by F. Cardone et al." Other authors also criticized Cardone's results. Nowhere in the scientific literature it results that Cardone's results have been reproduced or validated.

Though he is a "C3" technician of the National Research Council (CNR), Fabio Cardone is happy to call himself  “Professor”, and so do we. After all, he enjoys the support of the Army, of the political world and of Carpinteri, who is investing INRIM money to study piezonuclear reactions. In so doing, he is blocking sound science and destroying the enviable reputation of INRIM. Some say it’s a tragedy, some a commedia all’italiana, others invite yours truly to write "Piezopolis", a thriller involving nuclear waste traffic, shapely Russian spies, physicists and colonels smarter than Einstein rushing into the tunnels of San Cosimo for an ending à la James Bond. Meanwhile «extraordinary claims require extraordinary evidence», as they say in Brugherio. Like many scientists did for months, we asked Prof. Cardone and Roberto Mignani, can you cite one of those papers by scientists all over the world validating etc..? Mignani did answer and cited… a Startec brochure.

Sylvie Coyaud

Monday, May 7, 2012

Good night, Godzilla! Japan turns off nuclear energy

On May 5th, Japan has turned off its last operating nuclear plant. The nuclear monster, Godzilla, is sleeping. Is it just a nap or perhaps a long lasting hibernation? Only time will tell. 

The Japanese have always maintained an ambiguous attitude towards nuclear energy; not surprisingly after having seen some of their cities nuked during the second world war. So, at the same time as Japan was embarking in an ambitious nuclear program, in the 1950s, Godzilla appeared on the Japanese movie screens. A scaly monster somehow created by nuclear radiations, it had as main hobby that of destroying Tokyo by stomping on buildings and shooting beams of fire around.

In the Western imaginary, the ambivalent feeling about nuclear energy took the shape of the nuclear genie shown the 1957 Walt Disney movie "Our friend, the atom." In this more optimistic interpretation, the evil genie could be tricked into becoming a faithful servant. But that would not be the case for the Japanese nuclear monster. In time, Godzilla's personality and characteristics evolved and, occasionally, the ugly monster would be shown as helping humans in fighting other - even uglier - monsters. But Godzilla would always remain a tricky creature - beyond human control.

So, after the Fukushima disaster, Godzilla has been put to sleep: the last active nuclear plant in Japan was turned off on May 5th 2012. Will Godzilla sleep forever? It is impossible to say. What we can say is that if getting rid of nuclear plants means going back to fossil fuels, then the Japanese have simply replaced Godzilla with an even bigger, uglier, and infinitely more dangerous monster. While Godzilla could only destroy Tokyo, the climate change monster can destroy our whole civilization.

But that's not necessarily what the future has in store. It is possible to use renewable energy to replace fossil fuels and nuclear energy at the same time. Of course, it is a tremendously difficult challenge but Japan, with its large scientific and technological capabilities, is uniquely suited to meet it. With a lot of work and a bit of luck, the future of the world may not involve any more monsters.


See also "Godzilla vs. Global Warming" a short animation based on the idea that global warming is much worse than anything Godzilla could ever do.


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)