How the World Really Works: The Science Behind How We Got Here and Where We're Going

by Vaclav Smil

By the middle of the 18th century two French savants, Denis Diderot and Jean le Rond d’Alembert, could still gather a group of knowledgeable contributors to sum up the era’s understanding in fairly exhaustive entries in their multi-volume Encyclopédie, ou Dictionnaire raisonné des sciences, des arts et des métiers. A few generations later the extent and the specialization of our knowledge advanced by orders of magnitude, with fundamental discoveries ranging from magnetic induction (Michael Faraday in 1831, the basis of electricity generation) to plant metabolism (Justus von Liebig, 1840, the basis of crop fertilization) to theorizing about electromagnetism (James Clerk Maxwell, 1861, the basis of all wireless communication).

Most modern urbanites are thus disconnected not only from the ways we produce our food but also from the ways we build our machines and devices, and the growing mechanization of all productive activity means that only a very small share of the global population now engages in delivering civilization’s energy and the materials that comprise our modern world.

The proverbial best minds do not go into soil science and do not try their hand at making better cement; instead they are attracted to dealing with disembodied information, now just streams of electrons in myriads of microdevices. From lawyers and economists to code writers and money managers, their disproportionately high rewards are for work completely removed from the material realities of life on earth.

My goal is not to forecast, not to outline either stunning or depressing scenarios of what is to come. There is no need to extend this popular—but consistently failing—genre: in the long run, there are too many unexpected developments and too many complex interactions that no individual or collective effort can anticipate. Nor will I advocate any specific (biased) interpretations of reality, either as a source of despair or of boundless expectations. I am neither a pessimist nor an optimist; I am a scientist trying to explain how the world really works, and I will use that understanding in order to make us better realize our future limits and opportunities.

it is relatively easy to generate electricity by wind turbines or solar cells rather than by burning coal or natural gas—but it would be much more difficult to run all field machinery without liquid fossil fuels and to produce all fertilizers and other agrochemicals without natural gas and oil. In short, for decades it will be impossible to adequately feed the planet without using fossil fuels as sources of energy and raw materials.

The third chapter explains how and why our societies are sustained by materials created by human ingenuity, focusing on what I call the four pillars of modern civilization: ammonia, steel, concrete, and plastics.

I tend to think about modern scientists as either the drillers of ever-deeper holes (now the dominant route to fame) or scanners of wide horizons (now a much-diminished group).

Inevitably, this book—the product of my life’s work, and written for the layperson—is a continuation of my long-lasting quest to understand the basic realities of the biosphere, history, and the world we have created. And it also does, yet again, what I have been steadfastly doing for decades: it strongly advocates for moving away from extreme views. Recent (and increasingly strident or increasingly giddy) advocates of such positions will be disappointed: this is not the place to find either laments about the world ending in 2030 or an infatuation with astonishingly transformative powers of artificial intelligence arriving sooner than we think. Instead, this book tries to provide a foundation for a more measured and necessarily agnostic perspective.

Several hundred thousand years ago, the probes detect the first extrasomatic use of energy—external to one’s body; that is, any energy conversion besides digesting food—when some of these upright walkers master fire and begin to use it deliberately for cooking, comfort, and safety.[6] This controlled combustion converts the chemical energy of plants into thermal energy and light, enabling the hominins to eat previously hard-to-digest foods, warming them through the cold nights, and keeping away dangerous animals.[7] These are the first steps toward deliberately shaping and controlling the environment on an unprecedented scale. This trend intensifies with the next notable change, the adoption of crop cultivation. About 10 millennia ago, the probes record the first patches of deliberately cultivated plants as a small share of the Earth’s total photosynthesis becomes controlled and manipulated by humans who domesticate—select, plant, tend, and harvest—crops for their (delayed) benefit.[8] The first domestication of animals soon follows. Before that happens, human muscles are the only prime movers—that is, converters of chemical (food) energy to the kinetic (mechanical) energy of labor.

Domestication of working animals, starting with cattle some 9,000 years ago, supplies the first extrasomatic energy other than that of human muscles—they are used for field work, for lifting water from wells, for pulling or carrying loads, and for providing personal transportation.[9] And much later come the first inanimate prime movers: sails, more than five millennia ago; waterwheels, more than two millennia ago; and windmills, more than a thousand years ago.[10]

then in 1600 the alien probe will spring into action, and spot something unprecedented. Rather than relying solely on wood, an island society is increasingly burning coal, a fuel produced by photosynthesis tens or hundreds of millions of years ago and fossilized by heat and pressure during its long underground storage. The best reconstructions show that coal as a heat source in England surpasses the use of biomass fuels around 1620 (perhaps even earlier); by 1650 the burning of fossil carbon supplies two-thirds of all heat; and the share reaches 75 percent by 1700.[11]

the very beginning of the 18th century, some English mines begin to rely on steam engines, the first inanimate prime movers powered by the combustion of fossil fuel.

An average inhabitant of the Earth nowadays has at their disposal nearly 700 times more useful energy than their ancestors had at the beginning of the 19th century.

Energy conversions are the very basis of life and evolution. Modern history can be seen as an unusually rapid sequence of transitions to new energy sources, and the modern world is the cumulative result of their conversions.

Crude oil became a global fuel, and eventually the world’s most important source of primary energy, thanks to the discoveries of giant oil fields in the Middle East and in the USSR—and, of course, also thanks to the introduction of large tankers. Some Middle Eastern giants were first drilled in the 1920s and 1930s (Iranian Gachsaran and Iraqi Kirkuk in 1927, Kuwaiti Burgan in 1937) but most of them were discovered after the war, including Ghawar (the world’s largest) in 1948, Safaniya in 1951, and Manifa in 1957, all in Saudi Arabia. The largest Soviet discoveries were in 1948 (Romashkino in the Volga-Ural Basin) and in 1965 (Samotlor in Western Siberia).[42]

Between 1973 and 1975 the global economic growth rate dropped by about 90 percent, and as soon as the economies affected by higher oil prices began to adjust to these new realities—above all by impressive improvements in industrial energy efficiency—the fall of the Iranian monarchy and the takeover of Iran by a fundamentalist theocracy led to a second wave of oil price rises, from about $13 in 1978 to $34 in 1981, and to another 90 percent decline in the global rate of economic growth between 1979 and 1982.[47]

And even in this era of high-tech electronic miracles, it is still impossible to store electricity affordably in quantities sufficient to meet the demand of a medium-sized city (500,000 people) for only a week or two, or to supply a megacity (more than 10 million people) for just half a day.[51] But despite these complications, high costs, and technical challenges, we have been striving to electrify modern economies, and this quest for ever-higher electrification will continue because this form of energy combines many unequaled advantages. Most obviously, at the point of its final consumption, electricity’s use is always effortless and clean, and the majority of the time it is also exceptionally efficient. With just the flip of a switch, push of a button, or adjustment of a thermostat (now often requiring only a hand signal or voice command), electric lights and motors or electric heaters and coolers are turned on—with no bulky fuel storages, no laborious carrying and stoking, no dangers of incomplete combustion (emitting poisonous carbon monoxide), and no cleaning of lamps or stoves or furnaces.

By 1930, electric drive had nearly doubled American manufacturing productivity, and had done so again by the late 1960s.[55]

the history of electricity generation reminds us that many complications and complexities accompany the process; and that, despite its profound and rising importance, electricity still supplies only a relatively small share of final global energy consumption, just 18 percent.

nuclear fission began to generate commercial electricity in 1956 at Britain’s Calder Hall, saw its greatest expansion during the 1980s, peaked in 2006, and has since declined slightly to about 10 percent of global electricity generation.[65] Hydro generation accounted for nearly 16 percent in 2020; wind and solar added almost 7 percent; and the rest (about two-thirds) came from large central stations fueled mostly by coal and natural gas.

A very high reliability of electricity supply—grid managers talk about the desirability of reaching six nines: with 99.9999 percent reliability there are only 32 seconds of interrupted supply in a year!—is imperative in societies where electricity powers everything from lights (be they in hospitals, along runways, or to indicate emergency escapes) to heart-lung machines and myriad industrial processes.[69]

Ideally, the decarbonization of the global energy supply should proceed fast enough to limit average global warming to no more than 1.5°C (at worst 2°C). That, according to most climate models, would mean reducing net global CO2 emissions to zero by 2050 and keeping them negative for the remainder of the century.

the problems of intermittency of solar and wind generation could be resolved by renewed reliance on nuclear electricity generation. A nuclear renaissance would be particularly helpful if we cannot develop better ways of large-scale electricity storage soon.

We need very large (multi-gigawatt-hour) storage for big cities and megacities, but so far the only viable option to serve them is pumped hydro storage (PHS): it uses cheaper nighttime electricity to pump water from a low-lying reservoir to high-lying storage, and its discharge provides instantly available generation.[76]

Other energy storages, such as batteries, compressed air, and supercapacitors, still have capacities orders of magnitude lower than needed by large cities, even for a single day’s worth of storage.[77]

In contrast, modern nuclear reactors, if properly built and carefully run, offer safe, long-lasting, and highly reliable ways of electricity generation; as already noted, they are able to operate more than 90 percent of the time, and their lifespan can exceed 40 years. Still, the future of nuclear generation remains uncertain. Only China, India, and South Korea are committed to further expansion of their capacities.

we have no readily deployable commercial-scale alternatives for energizing the production of the four material pillars of modern civilization solely by electricity. This means that even with an abundant and reliable renewable electricity supply, we would have to develop new large-scale processes to produce steel, ammonia, cement, and plastics.

And what about countries that have not pushed renewables at extraordinary expense? Japan is the foremost example: in the year 2000 about 83 percent of its primary energy came from fossil fuels; in 2019 that share (due to the post-Fukushima loss of nuclear generation and the need for higher fuel imports) was 90 percent![82]

the US has greatly reduced its dependence on coal—replaced by natural gas in electricity generation—the country’s share of fossil fuels in primary energy supply was still 80 percent fossil in 2019. Meanwhile China’s share of fossil fuels fell from 93 percent in the year 2000 to 85 percent in 2019—but this relative decline was accompanied by a near tripling of the country’s fossil fuel demand.

economic rise of China was the main reason why the global consumption of fossil fuels rose by about 45 percent during the first two decades of the 21st century, and why, despite extensive and expensive expansion of renewable energies, the share of fossil fuels in the world’s primary e...

There are still significant numbers of children, adolescents, and adults who experience food shortages, particularly in the countries of sub-Saharan Africa, but during the past three generations their total has declined from the world’s majority to less than 1 in 10 of the world’s inhabitants. The United Nations’ Food and Agricultural Organization (FAO) estimates that the worldwide share of undernourished people decreased from about 65 percent in 1950 to 25 percent by 1970, and to about 15 percent by the year 2000. Continued improvements (with fluctuations caused by temporary national or regional setbacks due to natural disasters or armed conflicts) lowered the rate to 8.9 percent by 2019—which means that rising food production reduced the malnutrition rate from 2 in 3 people in 1950 to 1 in 11 by 2019.[4]

Many people nowadays admiringly quote the performance gains of modern computing (“so much data”) or telecommunication (“so much cheaper”)—but what about harvests? In two centuries, the human labor to produce a kilogram of American wheat was reduced from 10 minutes to less than two seconds.

the energy required to make and to power farm machinery is dwarfed by the energy requirements of producing agrochemicals. Modern farming requires fungicides and insecticides to minimize crop losses, and herbicides to prevent weeds from competing for the available plant nutrients and water. All of these are highly energy-intensive products but they are applied in relatively small quantities (just fractions of a kilogram per hectare).[14] In contrast, fertilizers that supply the three essential plant macronutrients—nitrogen, phosphorus, and potassium—require less energy per unit of the final product but are needed in large quantities to ensure high crop yields.[15]

Phosphatic fertilizers begin with the excavation of phosphates, followed by their processing to yield synthetic superphosphate compounds. Ammonia is the starting compound for making all synthetic nitrogenous fertilizers. Every crop of high-yielding wheat and rice, as well as of many vegetables, requires more than 100 (sometimes as much as 200) kilograms of nitrogen per hectare, and these high needs make the synthesis of nitrogenous fertilizers the most important indirect energy input in modern farming.[16]

in US cities, the average price of a kilogram of white bread is only about 5 percent lower than the average price per kilogram of whole chicken (and wholewheat bread is 35 percent more expensive!), while in France a kilogram of standard whole chicken costs only about 25 percent more than the average price of bread.[34] This helps to explain the rapid rise of chicken to become the dominant meat in all Western countries (globally, pork still leads, thanks to China’s enormous demand).

greenhouse tomatoes are among the world’s most heavily fertilized crops: per unit area they receive up to 10 times as much nitrogen (and also phosphorus) as is used to produce grain corn, America’s leading field crop.[38] Sulfur, magnesium, and other micronutrients are also used, as are chemicals protecting against insects and fungi. Heating is the most important direct use of energy in greenhouse cultivation: it extends the growing season and improves crop quality but, inevitably, when deployed in colder climates it becomes the single largest user of energy.

So, the evidence is inescapable: our food supply—be it staple grains, clucking birds, favorite vegetables, or seafood praised for its nutritious quality—has become increasingly dependent on fossil fuels. This fundamental reality is commonly ignored by those who do not try to understand how our world really works and who are now predicting rapid decarbonization. Those same people would be shocked to know that our present situation cannot be changed easily or rapidly: as we saw in the preceding chapter, the ubiquity and the scale of the dependence are too large for that.

Between 1900 and the year 2000, the global population increased less than fourfold (3.7 times to be exact) while farmland grew by about 40 percent, but my calculations show that anthropogenic energy subsidies in agriculture increased 90-fold, led by energy embedded in agrochemicals and in fuels directly consumed by machinery.[46]

Atmospheric deposition—mainly as rain and snow containing dissolved nitrates—and recycled crop residues (straws and plant stalks that are not removed from fields to feed animals or burned onsite) each contribute about 20 megatons of nitrogen per year. Animal manures applied to fields, mainly from cattle, pigs, and chickens, contain almost 30 megatons; a similar total is introduced by leguminous crops (green manure cover crops, as well as soybeans, beans, peas, and chickpeas); and irrigation water brings about 5 megatons—for a total of about 105 megatons of nitrogen per year. Synthetic fertilizers supply 110 megatons of nitrogen per year, or slightly more than half of the 210–220 megatons used in total. This means that at least half of recent global crop harvests have been produced thanks to the application of synthetic nitrogenous compounds, and without them it would be impossible to produce the prevailing diets for even half of today’s nearly 8 billion people.

the UK’s Waste and Resources Action Programme ascertained that inedible household food waste (including fruit and vegetable peelings, and bones) is only 30 percent of the total, meaning that 70 percent of wasted food was perfectly edible and was not consumed either because it spoiled or because too much of it was served.[65] Reducing food waste might seem to be much easier than reforming complex production processes, and yet this proverbial low-hanging fruit has been difficult to harvest.

Four materials rank highest on this combined scale, and they form what I have called the four pillars of modern civilization: cement, steel, plastics, and ammonia.[4]

global production of these four indispensable materials claims about 17 percent of the world’s primary energy supply, and 25 percent of all CO2 emissions originating in the combustion of fossil fuels—and currently there are no commercially available and readily deployable mass-scale alternatives to displace these established processes.[7]

Of the four substances (and despite my dislike of rankings!), it is ammonia that deserves the top position as our most important material. As explained in the previous chapter, without its use as the dominant nitrogen fertilizer (directly or as feedstock for the synthesis of other nitrogenous compounds), it would be impossible to feed at least 40 percent and up to 50 percent of today’s nearly 8 billion people. Simply restated: in 2020, nearly 4 billion people would not have been alive without synthetic ammonia. No comparable existential constraints apply to plastics or steel, nor to the cement that is required to make concrete (nor, as already noted, to silicon).

Ammonia is a simple inorganic compound of one nitrogen and three hydrogens (NH3), which means that nitrogen makes up 82 percent of its mass.[9]

Mao was responsible for the deadliest famine in history (1958–1961), and when he died in 1976 the country’s per capita food supply was hardly better than when he had proclaimed the existence of the communist state in 1949.[20]

The best account of recent nitrogen flows in China’s agriculture shows that about 60 percent of the nutrient available to the country’s crops comes from synthetic ammonia: feeding three out of five of the Chinese population thus depends on the synthesis of this compound.[23]

Urea, the solid fertilizer with the highest nitrogen content (46 percent), dominates.[28] Recently, it has accounted for about 55 percent of all nitrogen applied to the world’s fields, and it is widely used in Asia to support the rice and wheat harvests of China and India—the world’s two most populous nations—and to guarantee good yields in five other Asian countries with more than 100 million inhabitants.[29] Less important nitrogenous fertilizers include ammonium nitrate, ammonium sulfate, and calcium ammonium nitrate, as well as various liquid solutions.

Leo Hendrik Baekeland, a Belgian chemist working in New York.[38] His General Bakelite Company, founded in 1910, was the first industrial producer of a plastic that was molded into pieces ranging from electric insulators to black rotary dial telephones and, during the Second World War, used for parts in lightweight weapons.

steel is readily recycled by melting it in an electric arc furnace (EAF)—a massive cylindrical heat-resistant container made of heavy steel plates (lined with magnesium bricks), with a removable dome-like water-cooled lid through which three massive carbon electrodes are inserted. After loading the steel scrap, the electrodes are lowered into it, and electric current passing through them forms an arc whose high temperature (1,800°C) easily melts the charged metal.[68] However, their electricity demand is enormous: even a highly efficient modern EAF needs as much electricity every day as an American city of about 150,000 people.[69]

Affluent economies now recycle nearly all of their automotive scrap, have a similarly high rate (>90 percent) for reusing structural steel beams and plates, and only a slightly lower rate for recycling household appliances, and the US has recently recycled more than 65 percent of reinforcement bars in concrete, a rate similar to the recycling of beverage and food steel cans.[71] Steel scrap has become one of the world’s most valuable export commodities, as countries with a long history of steel production and with plenty of accumulated scrap sell the material to expanding producers. The EU is the largest exporter, followed by Japan, Russia, and Canada; and China, India, and Turkey are the top buyers.[72] Recycled steel accounts for almost 30 percent of the metal’s total annual output, with national shares ranging from 100 percent for several small steel producers to almost 70 percent in the US, about 40 percent in the EU, and to less than 12 percent in China.[73]