Quotes
They helped boost the economic might of countries by enabling people to work more; until the invention of lenses, those losing their sight would have to retire early, but thanks to bi-convex lenses in spectacle frames, millions of people were able to extend their working lives.
Yet for all that it is traduced, looked down on or misunderstood (it most certainly is not mud), concrete, a mixture of sand, aggregate and cement, is nonetheless quite extraordinary. Perhaps the best place to start is to ask a question: if you were looking to improve the lot of low-income families in poor parts of the developing world, which of the following would you provide for them? A bundle of cash, nutritional supplements or a bag of cement?
You already know where this is heading, of course, but let me explain: one of the biggest problems for young children in poor countries is intestinal parasites, which can damage their health and keep them from school. These parasites usually live in faeces, which often gets brought into the family home on the bottom of someone’s feet. If that home is a shack with a dirt floor, the parasites can go undetected for longer and get transmitted to more children.
A few years ago, Mexico began providing families with the cement to pave over dirt floors, with the consequence that parasitic infections dropped by 78 per cent. The number of children with diarrhoea dropped by half; those with anaemia dropped by four-fifths. There were all sorts of other happy outcomes too—children did better at school, their mothers became happier and less depressed. And all thanks to a cheap bag of cement.
To say that concrete is everywhere is hardly an exaggeration. Despite the fact that we only began mass producing this mixture of sand, aggregates and cement just over a century ago, there are now more than 80 tonnes of concrete on this planet for every person alive—around 650 gigatonnes in total. To put that slightly meaningless number into perspective, it is considerably more than the combined weight of every single living thing on the planet: every cow, every tree, every human, plant, animal, bacterium and single-celled organism. Each year we produce enough concrete around the world to cover the entire landmass of England.
The person who eventually solved the puzzle was a French doctor called Nicolas Leblanc, who came up with a two-stage operation that involves reacting the salt with sulphuric acid, cooking it with coal and limestone, and then soaking the resulting black ash. Despite building a plant to carry out the process in 1791, Leblanc never received the prize, for his discovery had coincided with the French Revolution and the king was on the run. Worse was to come for Leblanc: his plant was seized by revolutionaries who promptly sold it off and publicised his method. Leblanc committed suicide in 1806.
But the thing to ask yourself as you think back to the hole is not merely how it got so deep but how anyone could afford to dig it so deep? For as the miners here dug further down the cost of extracting the ores rose, even as the grades of those ores fell. And fall they did. As the twentieth century wore on the amount of copper in each new lump of rock here fell from 2.4 per cent in 1913 to down below 2 per cent by the middle of the century and below 1 per cent by its end. And as the grades fell, so the work of extracting the copper from the ores got significantly more demanding. Between 1900 and today, the quantity of stone one needed to move and process to produce a single tonne of copper rose from 50 tonnes to 800 tonnes. The amount of water consumed along the way went from 75 cubic metres to 150. The energy needed for all this work rose from around 250KWh to over 4,000KWh. Yet here is the most striking datapoint of all: over that period, rather than increasing, the inflation-adjusted copper price was essentially flat.
This is the first of the clues as to why Paul Ehrlich lost the bet; we became ever better at producing more stuff with less manpower. At the time of the Roman Empire the price of a tonne of pure copper was equivalent to roughly 40 years of the average wage. Forty years of work for a tonne of copper. By 1800 this had fallen to 6 years a tonne. In the following 200 years it dropped to just 0.06 years per tonne. For Paul Gait, a polymathic mining investor from London, this measure of the “real price” of copper is the big story here. It is a productivity miracle, just as impressive as Moore’s law for semiconductors—yet few people, even inside the sector, seem to be all that aware of it.
But what about the fact that there are only about 30 to 40 years’ worth of copper reserves left in the world? This, it turns out, is one of those statistics that is invariably misunderstood and misinterpreted, so it’s time for a brief lesson. When miners talk about the reserves they have left of a given material, that means everything they’ve got left in their mines or approved mine sites that could be economically extracted at any given moment. The reason we have about 30 to 40 years’ worth of copper reserves left (42 at the time of writing) is not because that is what’s left in the ground, but because that’s the kind of time horizon over which miners tend to make plans.
Yet every so often a report will emerge attempting to extrapolate from these reserves numbers that we are about to run out of this metal—The Limits to Growth was only the most famous study to attempt something along those lines. Reports of imminent catastrophe tend to get far more attention than hard statistics about the real world, so here’s a datapoint to keep in mind. Between 2010 and 2020 we mined 207 million tonnes of copper around the world, but far from falling, the total global reserves of copper grew by 240 million tonnes. Ponder that for a moment. Humankind is managing to increase our accessible supplies of this vital material at a rate that comfortably outpaces our actual exploitation of it.
In fact, a better number to focus on is not the reserves figure miners usually cite, but another number: the resources. Resources, it turns out, are a measure not just of what we have already pencilled in for future extraction, but all the metal under the ground, including stuff yet to be discovered. The figures here clearly involve a lot more guesswork, but they are also somewhat more reassuring: according to the U.S. Geological Survey, the world’s total copper resources are 5.6 billion tonnes, of which we have already discovered 2.1 billion tonnes. This works out at roughly 226 years’ worth of our annual copper consumption today—or about 115 years based on our consumption in a decade’s time, when the green energy transition is in full flow
What makes these six materials so special is not merely that they are so very good at what they do—from the electrical conductivity of copper to the energy density of oil—but a few other things too. The first is that we have worked out how to turn complex products into commonplace items. The smartphone in your pocket and the computer I’m typing this on are only the beginning of it. Everyone vaguely comprehends that the silicon chips inside them are objects of astounding complexity, though maybe not the extent of it—that the transistors are now far smaller than a virus and would be dwarfed by one of your red blood cells. However, the fact that so few people pay much attention is not something to despair about. It is a mark of success. It is all very well creating mind-blowing objects in a laboratory, but creating something that is both mind-blowing and goes inside the pockets of billions of people, where it works quietly and subtly and barely whispers of its brilliance…that really is a thing of wonder. The second is that these items are not merely commonplace but, more often than not, cheap. It was not always thus. Many centuries ago, glass was among the most precious manufactured products made by humans. Over time, however, its value has fallen so dramatically that what was once a luxury is now cheap and ubiquitous. Steel was once so special that only the richest rulers could afford a sword forged from it, but nowadays we manufacture nearly 2 billion tonnes every year. You could say something similar about powered flight, about motor cars, about painkillers or container freight. The cost of producing polyethylene, that plastic which exploded at the ICI labs at Northwich all those decades ago, fell by a third between 1958 and 1972 alone, and then carried on falling. The more we have made, the cheaper it has become.
That this [the significant price drop across time] happens across so many different products is no coincidence. Indeed, we have a name for the phenomenon: the learning curve. The more experience we have of making things, the better we get at doing them and the lower the cost, both for producers and consumers. This virtuous circle has been turning ever since the Phoenicians in Pliny’s story accidentally made glass on a Mediterranean beach and the men and women on the cliff at Boulby began to manufacture salt, though it wasn’t until the 1930s that someone came up with a formula for the phenomenon. That person was Theodore Wright, an American aeronautical engineer who had noticed that the cost of planes seemed to be falling year by year. Then he noticed the same thing with cars: a decade and a half after Henry Ford produced his first Model T, the price was down by three-quarters.
Ford, noticed Wright, was deploying one of the critical lessons laid down by Adam Smith in the first great economic work The Wealth of Nations, that by specialising in certain discrete tasks, humans can get more work done. These giant car plants in Detroit were where Smith’s notion of the “division of labour” became a large-scale reality. However, it wasn’t just the division of labour pushing down prices, but the slow accretion of experience. Over time, workers and their managers worked out how to produce even more cars (or rather the individual components of cars) with ever less effort. Their suppliers worked out how to provide better steel at lower prices. The chemical companies devised new paints which would dry faster and require fewer coats, meaning the factories could turn out even more vehicles.
As Wright observed this steady fall in prices and improvement in quality, he came up with a rule of thumb: every time the production of an item doubles, its cost falls by about 15 per cent. And Wright’s law, as it is sometimes called, has been eerily successful at explaining the fall in the price of everything from container ships to specialised plastics.
Yet there is an important distinction between this use of fossil fuels and the way we mostly used them in the preceding three centuries. Here, we are building with them, not burning them. Save for the coking coal, which helps us make metallurgical silicon, we are turning these fossil fuels into products, rather than a stream of energy, baking the embedded carbon into the stuff we use rather than releasing it into the atmosphere. We are harking back to what our forebears used to do, before they learned how to refine crude oil into kerosene, when the main use for it was to tar the bottom of boats and mortar bricks together. Building, not burning, is the name of the game in the coming decades, and the scale of that building project is almost certainly beyond what you’d imagined.