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

by Vaclav Smil

Why then do most people in modern societies have such a superficial knowledge about how the world really works? The complexities of the modern world are an obvious explanation: people are constantly interacting with black boxes, whose relatively simple outputs require little or no comprehension of what is taking place inside the box.

Urbanization and mechanization have been two important reasons for this comprehension deficit.

The other major reason for the poor, and declining, understanding of those fundamental processes that deliver energy (as food or as fuels) and durable materials (whether metals, non-metallic minerals, or concrete) is that they have come to be seen as old-fashioned—if not outdated—and distinctly unexciting compared to the world of information, data, and images.

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.

The real wrench in the works: we are a fossil-fueled civilization whose technical and scientific advances, quality of life, and prosperity rest on the combustion of huge quantities of fossil carbon, and we cannot simply walk away from this critical determinant of our fortunes in a few decades, never mind years.

Complete decarbonization of the global economy by 2050 is now conceivable only at the cost of unthinkable global economic retreat, or as a result of extraordinarily rapid transformations relying on near-miraculous technical advances.

The gap between wishful thinking and reality is vast, but in a democratic society no contest of ideas and proposals can proceed in rational ways without all sides sharing at least a modicum of relevant information about the real world, rather than trotting out their biases and advancing claims disconnected from physical possibilities.

Rather than resorting to an ancient comparison of foxes and hedgehogs (a fox knows many things, but a hedgehog knows one big thing), 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).

Drilling the deepest possible hole and being an unsurpassed master of a tiny sliver of the sky visible from its bottom has never appealed to me. I have always preferred to scan as far and as wide as my limited capabilities have allowed me to do.

This increasing dependence on fossil fuels is the most important factor in explaining the advances of modern civilization—and also our underlying concerns about the vulnerability of their supply and the environmental impacts of their combustion.

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.

And when put in terms of physical labor, it is as if 60 adults would be working non-stop, day and night, for each average person; and for the inhabitants of affluent countries this equivalent of steadily laboring adults would be, depending on the specific country, mostly between 200 and 240. On average, humans now have unprecedented amounts of energy at their disposal.

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.

those organisms that best capture the available energy hold the evolutionary advantage.

central notion of energy in all economies: “the economic system is essentially a system for extracting, processing and transforming energy as resources into energy embodied in products and services.”

Simply put, energy is the only truly universal currency, and nothing (from galactic rotations to ephemeral insect lives) can take place without its transformations.

Modern economists do not get their rewards and awards for being preoccupied with energy, and modern societies become concerned about it only when the supply of any main commercial form of energy appears to be threatened and its prices soar.

Understanding how the world really works cannot be done without at least a modicum of energy literacy.

Given these advantages and benefits, it was predictable—indeed unavoidable—that our dependence on crude oil would grow once the product became more affordable and once it could be reliably delivered on a global scale.

Could these new renewables produce enough electricity to replace not only today’s generation fueled by coal and natural gas, but also all the energy now supplied by liquid fuels to vehicles, ships, and planes by way of a complete electrification of transport?

For most of its inhabitants, the modern world is full of black boxes, devices whose internal workings remain—to different degrees—a mystery to their users. Electricity can be thought of as a ubiquitous and ultimate black box system:

despite its profound and rising importance, electricity still supplies only a relatively small share of final global energy consumption, just 18 percent.

Not surprisingly, demand for electricity has been growing much faster than the demand for all other commercial energy:

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] If the COVID-19 pandemic brought disruption, anguish, and unavoidable deaths, those effects would be minor compared to having just a few days of a severely reduced electricity supply in any densely populated region, and if prolonged for weeks nationwide it would be a catastrophic event with unprecedented consequences.

Reliance on fossil fuels has created the modern world, but concerns about the relatively rapid rate of global warming have led to widespread calls for doing away with fossil carbon as expeditiously as possible.

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.

Notice the key qualifying adjective: the target is not total decarbonization but “net z...

Given the fact that annual CO2 emissions from fossil fuel combustion surpassed 37 billion tons in 2019, the net-zero goal by 2050 will call for an energy transition unprecedented in both pace and scale.

Moreover (as will be explained in chapter 3), 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.

Annual global demand for fossil carbon is now just above 10 billion tons a year—a mass nearly five times more than the recent annual harvest of all staple grains feeding humanity, and more than twice the total mass of water drunk annually by the world’s nearly 8 billion inhabitants—and

Both the high relative share and the scale of our dependence on fossil carbon make any rapid substitutions impossible:

What we need is to pursue a steady reduction of our dependence on the energies that made the modern world. We still do not know most of the particulars of this coming transition, but one thing remains certain: it will not be (it cannot be) a sudden abandonment of fossil carbon, nor even its rapid demise—but rather its gradual decline.[85]

Now most people in affluent and middle-income countries worry about what (and how much) is best to eat in order to maintain or improve their health and extend their longevity, not whether they will have enough to survive.

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 modern world’s most important—and fundamentally existential—dependence on fossil fuels is their direct and indirect use in the production of our food.

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. This is how our modern world really works.

Most of the admired and undoubtedly remarkable technical advances that have transformed industries, transportation, communication, and everyday living would have been impossible if more than 80 percent of all people had to remain in the countryside in order to produce their daily bread

Today, as ever, no harvests would be possible without Sun-driven photosynthesis, but the high yields produced with minimal labor inputs and hence with unprecedented low costs would be impossible without direct and indirect infusions of fossil energies.

But the energy required to make and to power farm machinery is dwarfed by the energy requirements of producing agrochemicals.

synthesis of nitrogenous fertilizers the most important indirect energy input in modern farming.

Eventually, our food production will change, but for now, and for the foreseeable future, we cannot feed the world without relying on fossil fuels.

Given that vegans extol eating plants, and that the media have reported extensively on the high environmental cost of meat, you might think that gains in the energy cost of chicken have been surpassed by those in the cultivation and marketing of vegetables. You would be mistaken to think that.

As it turns out, capturing what the Italians so poetically call frutti di mare is the most energy-intensive process of food provision.

This means that just two skewers of medium-sized wild shrimp (total weight of 100 grams) may require 0.5–1 liters of diesel fuel to catch—the equivalent of 2–4 cups of fuel.

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.

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.

Anthropogenic energy inputs into modern field farming (including all transportation), fisheries, and aquaculture add up to only about 4 percent of recent annual global energy use. This may be a surprisingly small share, but it must be remembered that the Sun will always do most of the work of growing food,

The low share may also be seen as yet another convincing example of small inputs having disproportionately large consequences, not an uncommon finding in the behavior of complex systems:

But the energy required for food production—field farming, animal husbandry, and seafood—is only a part of the total food-related fuel and electricity needs, and estimating the use in the entire food system results in much higher shares of the total supply.

So, many changes are clearly desirable, but how fast can they actually happen, and how radically can we reform our current ways in reality?