Jevons Paradox

William Stanley Jevons
William Stanley Jevons (1835-1882)

As I look at the church’s responses to the impacts of climate changes I am deeply impressed and moved by the commitment shown by so many people. Yet I am also concerned that some of these efforts may be in vain. They may even be counter-productive. They may be unwitting victims of the Law of Unintended Consequences and of Jevons Paradox (the ‘Coal Question’).

False Savings

My first concern is to do with false savings. Let’s say that your place of work is near to your home. You have been in the habit of driving to work, but now decide to use a bicycle. You save a few gallons or liters of fuel each week. Great! You have done your bit to reduce the use of a scarce resource (oil) and you there are now fewer greenhouse gases in the atmosphere.

But has that gasoline really been saved? Since it is now available to others it will be used by someone, somewhere. So, the truth is that it has not been saved. It has merely been transferred from one consumer (you) to another (a stranger who could be anywhere in the world).

You may respond by saying that we need to make a gesture, or that cycling to work is good for your health. Fair enough — but the fact is that you have not met your original goal of reducing gasoline consumption and reducing the emission of greenhouse gases.

In fact, you may have made matters worse than if you had done nothing at all.

The Coal Question

In order to understand this conundrum let us meet that bewhiskered Victorian gentleman, William Stanley Jevons.

Mill Chimneys Victorian industry

Jevons was living at a time when Great Britain was going through a phase of rapid industrialization. The Industrial Revolution, which had started about 150 years earlier, was kicking into high gear.

In the year 1865 he published The Coal Question; An Inquiry Concerning the Progress of the Nation, and the Probable Exhaustion of Our Coal Mines (they went in for long book titles in those days). Even though he was writing 150 years ago, the words he wrote in that book are as relevant now as they were then (just substitute the word ‘oil’ for ‘coal’).

Coal 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 coal almost any feat is possible or easy; without it we are thrown back into the laborious poverty of early times. With such facts familiarly before us, it can be no matter of surprise that year by year we make larger draughts upon a material of such myriad qualities — of such miraculous powers.

. . . new applications of coal are of an unlimited character. In the command of force, molecular and mechanical, we have the key to all the infinite varieties of change in place or kind of which nature is capable. No chemical or mechanical operation, perhaps, is quite impossible to us, and invention consists in discovering those which are useful and commercially practicable . . .

I must point out the painful fact that such a rate of growth will before long render our consumption of coal comparable with the total supply. In the increasing depth and difficulty of coal mining we shall meet that vague, but inevitable boundary that will stop our progress.

Let us unpack those three paragraphs.

  1. The first paragraph states that coal was the über-commodity of the 19th century because it was the principle source of energy. Substitute the word ‘oil’ for ‘coal’ and his words apply to our situation. Without coal, without oil, we are “thrown back into the laborious poverty of earlier times”.
  2. The second paragraph shows the coal and oil not only give us raw power, they give us “molecular power” — the ability to create new products. They are used not only as fuel but also to create basic chemicals that in turn are used to make an enormous range of products such as fertilizers, medications, pesticides and plastics.
  3. But, and there’s always a ‘but’, in the third paragraph Jevons points out that the supply of coal is not infinite. Moreover, it will become ever more expensive to extract future supplies. We will never run out of coal or oil, but, sooner or later, we will run out of affordable coal (and oil). He is actually describing, a hundred years ahead of his time, the problem of declining ERoEI — Energy Returned on Energy Invested. He has a premonition of the Hubbert Curve.

His wonderful phrase, “that vague, but inevitable boundary that will stop our progress” pretty much summarizes much of what we are trying to achieve in this blog. There are no simple answers because there are no simple questions. But there are boundaries that will “stop our progress”.

I suppose that there is one other question that can be derived from the above statements. How is it that the quality of our written English has declined so precipitously? Where did we go wrong?

The Paradox

The following two statements summarize his famous paradox.

It is wholly a confusion of ideas to suppose that the economical use of fuel is equivalent to a diminished consumption. The very contrary is the truth.

Whatever, therefore, conduces to increase the efficiency of coal, and to diminish the cost of its use, directly tends to augment the value of the steam-engine, and to enlarge the field of its operations.

Translated into modern English, he is saying,

  • Coal is being burned with greater efficiency. (There were two reasons for this. The first is technological innovation, the second the economies of scale that ensue when the number of customers is increased.)
  • Hence more factories and power plants use coal since it is now economical to do so.
  • Hence the overall consumption of coal increases.

Apply the same thinking to our situation.

  • People buy fuel-efficient cars to save money.
  • Because their cars are more efficient, they drive more miles.
  • Also, because it is more economical to drive, more people buy cars.
  • Hence the overall consumption of fuel increases.
  • Hence we should all drive 1960 gas guzzlers. What’s not to like?
Red Cadillac gas guzzler
Now that’s an automobile

The Katy Freeway

Katy Freeway 26 lanes
The Katy Freeway

The idea of Jevons Paradox crops up everywhere.

I used to live in Houston, Texas, and frequently drove on the I-10 West (the Katy Freeway). It is a major, badly congested commuter highway. To reduce the congestion the freeway was expanded such that the intersection with Beltway 8 is now 26 lanes across. (There used to be a two-track railroad on the corridor but they tore it up to make room for more traffic lanes).

Once construction was complete, travel was much faster and more convenient for just a few weeks. But now the traffic is as bad as ever. Why? Because more people chose to drive to work, and real estate developers built more homes adjacent to the freeway.

Demand met supply.

Demand Reduction Is Crucial

Jevons Paradox leads us to the conclusion that demand reduction is crucial. Merely saving resources or improving efficiencies will do no more than keep us in one place; indeed, such activities may actually make things worse.

  • If you make steam engines more efficient then more factories and power plants will be built and coal consumption will increase.
  • If you add more lanes to freeways then more people will use those extra lanes, and congestion will be as bad as ever.
  • If you drive an economical car then other people will drive more miles and more people will buy cars, thus wiping out your sacrifice.

The lesson is simple:

Reducing consumption or pollution is of no value unless overall demand is reduced. Failure to heed this insight means that all attempts to address our predicaments through improved efficiency or consumption are doomed not only to fail, they may actually make those predicaments worse unless demand elsewhere, all over the world, is reduced correspondingly.


Child labour in a Victorian factory

I started this page by alluding to the fact that so many of our church friends are dedicated in their effort to help those who have been hurt, in one way or another, by climate change and related problems.

Jevons was with them. Far from being a cold-hearted economist who had no concern for the needs of those in trouble, he showed compassion. Here is what he said (once more, using a quality of English that one can only envy).

We must begin to allow that we can do today what we cannot so well do tomorrow….

Reflection will show that we ought not to think of interfering with the free use of the material wealth which Providence has placed at our disposal, but that our duties wholly consist in the earnest and wise application of it. We may spend it on the one hand in increased luxury and ostentation and corruption, and we shall be blamed. We may spend it on the other hand in raising the social and moral condition of the people, and in reducing the burdens of future generations. Even if our successors be less happily placed than ourselves they will not then blame us.


Any attempt to “save” energy or to reduce emissions is likely to have limited success unless it is matched with a commensurate reduction in energy consumption and emissions everywhere by everyone.

Now that’s the real challenge.

Happy Motoring Esso 1950s

Author: Ian Sutton

Ian Sutton is a chemical engineer who has worked in the chemical, refining and offshore oil and gas industries. He is the author of many books, ebooks and videos.

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