1 - L'énergie - Cours des Mines 2019 - Jancovici - [EN subtitles available]

I’m going to give you a lecture on, let’s say, two objects that will accompany you throughout your personal and professional life from now on, and, besides, also since the past, which are called energy and climate change. So I’m not an academic. My job is to be a consultant.

I am a partner in a consulting firm. I have a second job as President of an association. And I do extension work that eventually led to this course.

That’s why I do this job rather than my main job. The course I’m going to give you is essentially a course based on observational data, relatively simple reasoning with hands. I hope it will be accessible.

It is not very different (to be very frank) from a number of things that I can tell in other forums for audiences that have not been carefully selected through contests. So, normally you should be able to keep up. I’m still going to remind you of a couple of little things as an appetizer.

The first is that you will remember much more easily what I say if you take notes (even if you trash them afterwards) rather than if you don’t take them. So it’s a very good mnemonic way to take notes. The second thing is that I will try in particular to invite you to always approach problems by reasoning by orders of magnitude and rules of 3.

You have entered this school having been carefully selected for your above‑average ability to solve complicated problems that are well‑posed. All right? You have been selected to enter this school for solving problems that are univocal: they have only one solution.

Perhaps a little complicated, but they have only one solution, and they are well‑posed. That is to say, in the problem, you have all the information you need to find the solution. Life and what I’m going to tell you from now on is essentially made up of ill‑posed problems where you don’t have all the information.

All right? And when we approach a problem that is ill‑posed and that we do not have all the information, there is something that is extremely effective in addressing these problems — and it will be particularly true in what I am going to tell you — it is to reason by orders of magnitude and rules of 3. And everywhere in your life, if a sophisticated model is not in line with a well‑established rule of 3, it is because the model is wrong!

So here are some elements that I give you as a preamble to the course that we will have the pleasure of going through together. This is one of the most famous pensioners in France. He is retired because he would have said he was going to stop working, but that must not be entirely true because from time to time we see him do things that are less fun than that.

It doesn’t matter. So we’re going to get him back in a little bit of service. When you ask a question in the Millionaire Game, for those of you who have already watched this excellent game, you know that you are given four answers in advance.

That is, you are told: “Here is the student sitting there in the second row, does he have a shirt a) blue, b) green, c) yellow, d) black” and all those who were currently sleeping are failing, the others have the right answer. Now, we will imagine that he asks a question in an open way, that is, he asks you: “What is energy? ” You know that in France there is a Minister of Energy so you could ask him: “What is energy?

” Normally, he should know since he is the Minister of Energy. Well, you would realize, if you asked the question (I’ll give you an example in a few minutes), that in fact, the first answer that comes to the bulk of the population, I mean the bulk of the population, so I’m not talking about the world in which you live on a daily basis. It’s this.

That is, if you say “energy” in a number of forums and in particular in a forum that we call “general public”; the first thing that will come to mind for many people — and in fact it is normal because it is also the first way to present energy in the world of economists — is that it is something that is bought: a convenience. It’s a thing to buy and so the main subject is whether it’s expensive or cheap, and if we could do it differently to get the same thing for less expensive. This is particularly true in the news since for all of you who have followed this kind of movement, you know that it started with a dispute over fuel prices.

So, of course, that is not the main issue at the end of the day, but it started with this dispute, which was a dispute over fuel prices. So, the Yellow Vests never said: “We don’t want to consume fuel because it’s too much CO2” or “We don’t want to consume fuel because it makes us dependent on Russia, Norway and we don’t want to. ” No, no.

They were just saying: “It’s too expensive. ” All right? So what I’m going to try to explain to you during part of the rest of this course is that, if you look at the problem from that perspective, unfortunately, you’re missing the point.

There are several reasons why we are missing the point. The first is that if you look in strictly economic terms what it costs to buy energy in relation to what you earn. And you can represent it in several ways.

One of the ways I represent it is to look at what it costs to buy each year from the whole economy, to buy the oil, gas and coal that made it work. So, I look at the whole economic product of the year and I look, in relation to this economic product, what it costs to buy on the market all the oil we consume in the year, all the gas we consume in the year (I speak for the world as a whole) and all the coal we consume in the year. Well, the result I get is that it costs a few percent of what we earn.

A few percent of what we earn. I will show you a graph in a short while on how much it costs the French to buy energy and I assure you that to pay Free, SFR or Orange (sorry I didn’t name anyone) to say: “Hello, I’m late” or “Where are you? ” It costs roughly the same price.

About the same price. It costs a few percent of what we earn. And from the moment an object placed in an economic debate represents a few % of the debate, well, at that moment, the normal reflex will be to say: “I will take care of it a few % of the time.

” And typically, what you see right now in political debates is: I’m interested in energy at election time a few percent of the time and then, the rest of the time, I delegate the problem by telling them: “Make sure that this thing is managed in your own corner, it’s not really my problem. I do not see the link with pensions, diplomacy, economic policy or the number of printers in the country. There is no connection.

So I will consider it a subject that can be detached from the rest and only requires a few percent of my time. ” What I’m going to tell you from now on is that this reasoning is as relevant as if I told you: “Your brain is 2% of your weight, so I can remove it from you, it’s not very serious, you’ll lose 2% in efficiency. ” So, “pie chart” reasoning (and that’s something that’s broader than just energy) “pie chart” reasonings never tell you if the “pie pieces” are enslaved to each other or not.

There is another funny reasoning of the same type which is to say: “Agriculture is 2% of GDP so we don’t care, we can dump it, it doesn’t matter much. ” Well, yes, except that if you stop eating, the remaining 98% of GDP, quite quickly, will be problematic. So, the “pie chart” reasonings, you always have to be very wary of the fact that it doesn’t represent the dependence you can have on one “piece of pie” to another.

And what I’m going to show you now is that, in fact, the dependence of the 97 or 98 or 95% of GDP that are not energy purchases, in fact, is totally 100% dependent in the modern world on the 5% in question. So, energy is not an invoice, even if … Well, objectively, it is not just an invoice even if that is how we reason in the economic world in which we live. There is another thought that often comes to mind when we talk about energy.

It’s people telling you: “Ah, energy, good energy, that’s the energy we save. ” So, the second thing I’m going to show you during this course is that if you’re in this room right now with the time, at your choice, to sleep for those who take a nap or to listen, instead of being picking potatoes, it’s precisely because the World has been increasingly consuming energy over the past two centuries. [Sorry.

] So, in fact, the result of the world we live in today is a world of growing energy abundance and not at all a world of growing energy savings. So, in fact, the right energy, in the sense of the one that allowed the emergence of the industrial civilization in which we live, is precisely the one that we have not saved. The third topic that is very popular at the moment is that: “Energy is not very serious to know what it is.

What is important is that it will become 100% renewable. ” You will see that, in fact, that is not exactly how it happened. And, in fact, the right way to approach energy could be the poet’s.

That is, energy is what you are filled with on a morning when you are in good shape (or an afternoon, it depends on when you get up). Well, in fact, this way of seeing things is the right way because, when you consider that you are full of energy, in fact what it means is that you consider you have a great ability to control your destiny. “I have a lot of energy, I’m very fit”, that means, basically, “there’s not much I am afraid of”, and so, “I have a great ability to control my destiny”.

But energy, as we will see from now on, is that, having a lot of it, is precisely having a great ability to control your environment. It’s that by definition. By definition, having a lot of energy means having a great ability to control your environment.

And why is that? Because energy, before being an invoice or before being a subject of debate, is a physical quantity. So you know it well because you have done a little bit of physics to get into this amphitheatre, energy is a physical quantity.

It’s quite funny, moreover, because in physics there is no totally univocal definition of energy. I’ll suggest one for you. For me, energy is what quantifies the change of state of a system.

All right? Energy is what quantifies, I mean quantifies, calculates, the change of state of a system. In other words, the more the world around you changes, the more energy has come into play.

And, the more energy that comes into play, the more the world around you changes. It’s as simple as that. So if I take this back to transformations in everyday life, here are some of them, or more precisely objects that transform the environment in everyday life.

These are objects that transform the temperature. These are objects that are intended to change a temperature, which I show you here. Either to heat or to cool down.

And these objects use or eventually release energy. Here are some objects to change a velocity. That’s all a car is for.

It is used to change the speed of what is contained in the car, eventually you and your luggage when you go on holiday. Well, a speed change is a change in the state of a system. Here are some objects to change a shape.

You had soil, the soil is excavated, it is placed next to the hole. Change of form. You had a sheet metal, the sheet metal is stamped and you have a car door.

Change of form. These machines use energy. You have energy that comes into play when you change a chemical composition.

And, by the way, the first chemical composition that constantly changes to provide energy in your immediate universe is called your digestion of the food you eat. Actually, that’s what they’re for. They are used to provide you with energy.

You have energy that comes into play when you have magnetic fields that interact with electric currents. So, it can either consume it, in an engine, or “supply it”, in an alternator. You have energy that comes into play when you rearrange the nucleons of a nucleus.

And you know the sun spends its time doing that. It is a large permanent thermonuclear bomb that spends its time assembling hydrogen nuclei to make helium nuclei. You have energy that comes into play when you have material‑radiation interactions.

So, the interaction of matter and radiation that interests you the most is your smartphone. But in the end, there is more to it than that in the interaction of matter and radiation. One that will be of great interest to you, and to me too in a month and a half represented by this young woman on the right.

So, in a general way, using energy is nothing more than transforming the world around us and conversely, transforming the world around us necessarily implies that there is energy involved. So, once I told you that, a first small remark. Man is in transition.

You know that we currently have a Ministry of Energy Transition and not just a Ministry of Energy. We have a Ministry of Energy Transition. Well, the Ministry of Energy Transition is probably the oldest Ministry in the human community, since Men have been in energy transition for 500,000 years.

Five hundred thousand years ago, the only energy that humans could use was their bodily energy. And then, they started to domesticate the fire, so a first extracorporeal energy. In Antiquity, we started to domesticate all renewable energies and, by the way, even some fossil fuels.

For example, oil was known to the Sumerians, coal was known to the Chinese a few thousand years ago, so in small doses all this. And in fact, the industrial revolution was the domestication of fossil fuels, we will come back to that. And so, the energy transition is a permanent state of human beings.

Every time they find a way to use a new energy source, they do it. What characterizes the modern era (and you will see that it characterizes it extremely strongly and that is what poses a problem) is that we have radically changed the order of magnitude in all these processes in a very, very short time. So energy, as I told you, is a physical quantity.

From the moment I said that energy is a physical quantity, it means that there is every chance that energy will be governed by laws that we cannot change. That's the charm of the laws of physics. It's that you can understand what Maxwell’s equations are, but once you understand them, you can’t change them.

You can’t say: “Well, it would be nice for the purchasing power of consumers if we could change Maxwell’s equations a little bit. ” No need to try. Well, as far as energy is concerned, you have a few laws that apply to us and that cannot be changed.

So, it is not to say that we do not try to change them from time to time implicitly by votes in the National Assembly, but, nevertheless, it is better to know them. So, as I told you, energy is what quantifies the transformation of the environment. The first cardinal law that is very simple to keep in mind when it comes to energy and that you all know by heart, of course, is the first principle of thermodynamics or energy conservation law.

So, the energy conservation law applied to humans has a consequence that is simplistic, which is that humans can do nothing more than extract from the environment an energy that already exists and use it for their benefit. That’s all Men are capable of doing. If Men were able to make energy appear within them without communicating with the outside, we would be violating the first principle of thermodynamics.

So, I’m sure that in a good Harry Potter, … (the text continues) … That is to say, it will not be a world of expansion, it will be a world of contraction. So we’re going to need your creative genius because I assure you that managing a shrinking world is much more challenging as a constrained optimization exercise than managing an expanding world. So, we’re really going to need you.

We also need me, but we’re really going to need you… In the sense that we’re really going to need the best selected brains in the country to tackle one of the toughest problems we will have to solve, which is to keep the system more or less stable in a context of shrinking available resources. I can assure you that what you saw in the written and oral part of the contest was an easy part compared to that. I take the OECD area as a whole and I’m going to end up with that.

Same motive, same punishment. The supply per person increases until 79, peaks in 2006 — and this is also true in the United States. In the United States, the energy supply per person went through a maximum two years before Lehman Brothers, I insist.

And, you also have this evolution that actually reflects a trend evolution that has taken place for a very long time, and therefore it will probably happen about the same thing in that area and then in the world as a whole. There you go.