How the World Really Works by Vaclav Smil

Core Frameworks Deconstructed

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Citation: All text highlighted in yellow in this section is cited from – Smil, Vaclav. How the World Really Works: A Scientist’s Guide to Our Past, Present and Future. Paperback. 2022.

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Energy

The more fundamental something gets, the more difficult it is to define it. And energy is fundamental. Therefore, unsurprisingly, Smil writes: “Energy is among the most elusive and most misunderstood concepts …” – Nonetheless, one can understand energy as the capacity to do work or cause change.

The way to make energy useful is to convert it into a form that is useful to us. For example, thermal energy in steam is made useful by converting it into kinetic energy by having the steam push a piston rod that moves the stream engine. Therefore, Smil rightly says: “… it is more revealing to look at energy that is actually available for conversion into useful forms.” Indeed, we can say these conversions of energy from one form to another are the basis for all life and evolution.

In physics, this distinction is captured by the concept of useful energy versus waste energy. Every conversion leaks energy—usually as low-grade heat—because of the second law of thermodynamics. No process is 100% efficient. What matters is how much usable energy survives the conversion.

Seen this way, energy conversion is not just an engineering concern; it is the foundation of life itself. Photosynthesis converts solar radiation into chemical bonds. Metabolism converts those bonds into motion, growth, and maintenance. Evolution favours organisms—and societies—that discover more efficient, more reliable ways to capture and convert energy gradients.

Human history is essentially a long story of expanding energy conversion capabilities: from fire, to muscle power, to wind and water, to fossil fuels, to electricity. Each leap didn’t increase energy in existence; it increased energy under use. And with each increase came greater complexity—cities, institutions, technology, and culture—along with greater fragility when those flows are disrupted.

Now we can appreciate why Smil chose to start with energy as the first thing to discuss when explaining how the world works. “Simply put, energy is the only truly universal currency, and nothing … can take place without its transformations.”

Fossil fuels dominate for a reason

For the most part, fossil fuels serve humanity’s energy appetite. For most of modern history—and still today—fossil fuels dominate humanity’s usable energy supply because they combine three properties no alternative has yet matched at global scale, more on this in a bit.

Plus, an energy source must meet the following three criteria of usefulness: production, storage, distribution. Fossil fuels in general, and hydrocarbons in particular, win out here.

Production

An energy source must be producible in large quantities, predictably, and with a favourable energy return. Fossil fuels excel here because extraction technologies are mature, scalable, and geographically widespread. Once a coal mine, oil well, or gas field is operating, output can be sustained and ramped with relative precision for several decades. Many renewable sources, by contrast, are constrained by intermittency or geography; their production fluctuates frequently due to weather, seasons, and location.

Storage

Energy must be storable without excessive loss, cost, or complexity. This is where hydrocarbons decisively outperform alternatives. Coal piles, oil tanks, and gas reservoirs can store vast amounts of energy for months or years with minimal losses. Batteries, pumped hydro, and other storage technologies exist, but they are expensive, material-intensive, and currently inadequate for storing energy at the scale and duration required to backstop entire cities. Smil writes: “In large, populous nations, the complete reliance on these renewables would require what we are still missing: either mass-scale, long-term (days to weeks) electricity storage that would back up intermittent electricity generation, or extensive grids of high-voltage lines to transmit electricity across time zones and from sunny and windy regions to major urban and industrial concentrations.”

By contrast, most renewable energy sources are diffuse. Sunlight is abundant, but spread thinly across space and time. Wind carries energy, but intermittently and unevenly. Capturing them requires large surface areas, complex systems, and significant material inputs — and once captured, storing that energy at comparable density becomes the next bottleneck.

Batteries illustrate this constraint vividly. Even the best modern batteries are an order of magnitude lesser energy dense (Smil estimates more than 40 times less energy dense) than liquid fuels. This isn’t a failure of engineering effort; it’s a consequence of chemistry. Lower density means more weight, more materials, more cost, and more infrastructure for the same delivered work — especially problematic for aviation, shipping, and long-haul transport.

Distribution

Energy must be transportable to where it is needed, when it is needed. Liquid hydrocarbons are uniquely advantageous since they are energy-dense, stable, and easily moved via ships, pipelines, rail, and trucks. This flexibility is why modern transport, global trade, and just-in-time supply chains evolved the way they did. Electricity, by contrast, is difficult to store and must be consumed the moment it is produced, making distribution far more complex and fragile.

This is why hydrocarbons “win”—not because they are clean or ideal, but because they solve all three problems simultaneously. Many proposed green solutions address production but struggle with storage and distribution. Others shift the burden to unseen systems—massive grids, rare materials, or backup fossil capacity—without acknowledging the trade-offs. For advocates of a green transition, replacing fossil fuels means replacing their functions, not just their outputs. Until alternatives can match hydrocarbons across production, storage, and distribution at scale, transitions will be slower, messier, and more constrained than optimistic narratives suggest.

Fossil fuels are not about to run out

Proven reserves of coal, oil, and natural gas are sufficient for many decades at current consumption levels (Smils reckons our coal reserves will last another 120 years, and oil and gas reserves another 50 years), and historically, reserves tend to increase as exploration, technology, and prices change.

Scarcity is not the primary driver for moving away from fossil fuels. Environmental impact is — climate change, air pollution, ecosystem damage, and long-term planetary risk.

However, acknowledging that reality immediately complicates the popular narrative around net-zero by 2050. Smil’s argument is not that decarbonisation is unnecessary, but that the pace and scope implied by net-zero pledges collide with physical and industrial realities.

Where is decarbonisation relatively feasible? Electricity generation is the most tractable domain.

Where is decarbonisation hard? Other sectors are far more resistant to rapid change:

• Heavy industry (steel, cement, chemicals) – These require high-temperature heat and chemical reactions that electricity cannot easily replace. Cement alone emits CO₂ not just from fuel, but from the chemistry of limestone itself.
• Aviation and shipping – These depend on ultra-high energy density fuels. Batteries are fundamentally unsuitable at scale, and alternatives like synthetic fuels or hydrogen face efficiency, cost, and infrastructure hurdles.
• Agriculture – Modern food systems depend heavily on fossil fuels — not just for machinery and transport, but for fertilizers derived from natural gas. Decarbonising food without collapsing yields is nontrivial.
• Materials and infrastructure – Building the renewable transition itself requires massive amounts of steel, concrete, copper, rare earths, and energy — much of it currently fossil-fuel-powered.

Why is net-zero by 2050 such a stretch?

The problem is not intent; it is time, scale, and inertia.

Energy systems are among the largest, slowest-moving systems humans have ever built. Historically, major energy transitions (wood to coal, coal to oil) took many decades, often more than a century, even when the new source was cheaper and superior on multiple dimensions.

Today’s transition asks for: faster change, across more sectors, under tighter constraints, with higher global demand, and uneven development needs. That doesn’t make net-zero “wrong,” but it does make it aspirational rather than predictive.

Even in an optimistic case, “… it is highly improbable that this [reliance on fossil fuels] could be cut close to zero in a single decade.”, “… it will not be … a sudden abandonment of fossil carbon … but rather its gradual decline.”

Food

Nothing exposes our ignorance of physical systems more clearly than how casually we treat food abundance. For almost all of human history, producing enough food was the dominant constraint on population size, health, and social stability. Hunger was normal. Famine was cyclical. A large fraction of human labour was devoted simply to growing calories, often with miserable efficiency. Our modern world of abundant, perhaps overabundant food, feels “normal” to us because we have forgotten how exceptional our current situation is.

The ability to produce vastly more food with far fewer people is one of the most consequential achievements in human history, “… no recent transformation … has been so existentially fundamental as our ability to produce, year after year, a surfeit of food.” It is as transformative as electricity or antibiotics, yet far less appreciated.

The Game-Changer

The key reason that led to such a dramatic increase in our ability to produce food was our ability to use fossil fuels (and the electricity we could generate from them): “… we could not harvest such abundance, and in such a highly predictable manner, without the still-rising inputs of fossil fuels and electricity.”

Fossil fuels have entered agriculture at every critical point of the system:

• Muscle replacement: Tractors, harvesters, irrigation pumps, and transport replaced animal and human labour. One farmer today feeds hundreds of people because machines, powered by fossil fuels, do the work that once required entire villages.
• Synthetic fertilisers: The Haber–Bosch process, which fixes nitrogen from the air using natural gas, is arguably the single most important technological intervention in human history. Roughly half of the nitrogen in your body today comes from synthetic fertilisers. Without fossil fuels, modern crop yield would collapse. “… the Green Revolution could not have taken place without this combination of better crops and higher nitrogen applications.”
• Pesticides and herbicides: These are fossil-fuel-derived chemical products that protect yields from losses that once made farming precarious and unreliable.
• Global logistics and cold chains: Food can now be grown where conditions are optimal and consumed thousands of kilometres away. Refrigeration, shipping, and storage — all energy-intensive — dramatically reduce spoilage and famine risk.

The result was a step change in yield, reliability, and scale. Agriculture stopped being a subsistence gamble and became a predictable system capable of supporting billions of people. This surplus is what enabled urbanisation, specialisation, modern medicine, and education. In Smil’s framing, modern civilisation sits on a fossil-fuel-powered agricultural base, whether we like it or not.

Too much of a good thing

However, modern agriculture didn’t just solve scarcity; it overshot into excess. When production is optimised almost exclusively for yield and scale, secondary effects compound—until they are no longer secondary.

• First, waste. A significant share of food produced never nourishes anyone. Losses occur at every stage: overproduction at farms, spoilage in transport, aesthetic rejection by retailers, and excess consumption followed by disposal. From an energy perspective, this is absurd: vast amounts of fossil energy are converted into calories that end up in landfills, emitting methane as they rot.
• Second, greenhouse gas emissions. Agriculture is now a major contributor to climate change—not only through CO₂ from machinery and transport, but through nitrous oxide from fertilisers (a far more potent greenhouse gas than CO₂) and methane from livestock. These emissions are tightly coupled to how intensively we farm, not just how much food we eat.
• Third, biodiversity loss. High-yield monocultures simplify ecosystems. Hedgerows disappear, insects vanish, soil microbiomes degrade. What looks efficient in the short term erodes the biological foundations that make agriculture resilient in the long term.
• Fourth, nutrient runoff and dead zones. Excess nitrogen and phosphorus from fertilisers don’t stay neatly in fields. They wash into rivers, then into seas, creating oxygen-depleted “dead zones” where marine life collapses. These zones are not theoretical—they are measurable, expanding, and tightly linked to industrial farming practices.

Let’s be practical

But thinking we can dial back dependence on fossil fuels is theoretical. Smil is cautious about simplistic narratives around “going back” to pre-industrial or purely organic systems: “… purely organic farming would require most of us to abandon cities, resettle villages, dismantle central animal feeding operations, and bring all animals back to farms to use them for labor and as sources of manure … I do not foresee the organic green online commentariat embracing these options anytime soon. And even if they were willing to empty the cities and embrace organic earthiness, they could still produce only enough food to sustain less than half of today’s global population.”

But all in all, fossil fuels are here to stay and so is their impact on our climate. Here’s Smil again: “… even if we try to change the global food system as fast as is realistically conceivable, we will be eating transformed fossil fuels, be it as loaves of bread or as fishes, for decades to come.”

By contrast, reducing waste and reshaping demand are immediately actionable levers, even if they feel less heroic. Cutting food waste means fewer inputs for the same nutritional outcome—less land, less fertiliser, less fuel, fewer emissions. The gains here are real, cumulative, and achievable without waiting for new technologies or radical restructuring. Similarly, nudging dietary patterns—moderating excessive meat consumption, reducing over-processed foods, aligning intake with actual nutritional needs—directly reduces pressure on energy- and resource-intensive production chains.

What makes these measures counterintuitive is that they don’t sound transformational. They lack the drama of a “revolution.” But Smil’s worldview consistently favours incremental realism over grand declarations. Changing what we produce is slow and constrained; changing how much we waste and what we choose to consume is faster and cheaper, even if politically and culturally uncomfortable.

Four pillars of the modern material world

It’s easy to believe the modern world runs on silicon. Screens are everywhere. Software mediates work, communication, finance, and entertainment. But Smil points out that this is a category error. Silicon enables coordination; it does not build the physical world.

He writes: “We could have an accomplished and reasonably affluent civilization that provides plenty of food, material comforts, and access to education and healthcare, without any semiconductors, microchips, or personal computers.” The true foundations of modern civilisation are far more prosaic — and far more material: ammonia, plastics, steel, and concrete.

This is why Smil is so sceptical of slogans and deadlines. These are not sectors you decarbonise with better intentions, clever software, or consumer nudges alone. They are heavy, slow, capital-intensive systems with long lifespans, massive installed bases, and few ready substitutes.

Retrofitting or replacing them means rebuilding furnaces, kilns, reactors, supply chains, and infrastructure that took decades to construct: “… even if the aggressive pursuit of non-carbon options were to take place, it would obviously take decades to displace the existing capacities that are producing, at affordable prices, [and] at annual rates of hundreds of millions to billions of tons.”

Ammonia

The first among equals of the four foundations, and the material that feeds at least half of the world. If we did not have ammonia, there would only be four billion of us populating the planet than the eight billion today. Ammonia is the quiet pillar holding up modern civilisation — so quiet that most people never notice it at all. It doesn’t glow on screens, doesn’t trend on social media, doesn’t inspire keynote talks or startup decks.

This is why the number matters: without ammonia, the planet would not support eight billion people. It would support something closer to four billion, and that’s being generous. There is no hidden, organic-only alternative waiting in the wings that can bridge that gap without massive land expansion, ecosystem destruction, and widespread hunger. Any serious discussion about sustainability that ignores this fact is not serious.

Plastics

Plastics are so deeply woven into modern life that listing their uses quickly becomes a fool’s errand. Packaging, medicine, electronics, transport, construction, textiles, insulation, agriculture—the list never ends. May I suggest a better thought experiment: try to identify places where plastics have not penetrated. You will struggle.

They reduced food spoilage, enabled sterile medical environments, lightened vehicles (improving fuel efficiency), insulated buildings, and lowered costs across supply chains. In many cases, removing plastics without careful substitution would increase energy use and emissions rather than reduce them.

This is why Smil resists simplistic solutions like “just ban plastic.” The material itself is not the core problem; how we design, use, and discard plastics is. Short-lived, disposable applications dominate production growth, even though plastics are inherently durable materials. That mismatch—durability designed for minutes of use—is the real failure of system design.

The uncomfortable implication, once again, is that modern civilisation is materially dependent in ways most people barely register. Plastics are not a side issue; they are a load-bearing component of how we feed, heal, move, and house billions of people. Any serious attempt to reform their use must begin with acknowledging why they spread so fast in the first place—and why replacing them is far harder than slogans suggest.

Steel

Steel is one of those materials whose importance is so obvious that it fades into the background. We notice software upgrades and gadget launches; we almost never notice the material that physically holds the world together.

What makes steel indispensable is its rare combination of properties. It has high tensile strength (it resists being pulled apart), high compressive strength (it resists being crushed), and it retains structural integrity at very high temperatures. Very few materials do all three well, and none do so at steel’s cost, scale, and reliability. This is why steel is everywhere that load, stress, heat, and safety matter: buildings, bridges, railways, ships, pipelines, power plants, machinery, tools, and vehicles.

\Any vision of a low-carbon future still requires vast amounts of steel—often more than today—to build renewable infrastructure, grids, transport systems, and cities for growing populations. Paradoxically, the energy transition itself is steel-intensive.

So steel teaches the same lesson ammonia and plastics do: modern civilisation rests on materials that are abundant but energetically expensive. We are not constrained by geology so much as by physics and thermodynamics. Understanding that distinction is essential if we want to plan transitions that are feasible rather than fanciful.

Concrete

Finally, let’s talk about the “… most massively deployed material of modern civilization, hard and heavy and able to withstand decades of punishing use, particularly when it is reinforced with steel.” – concrete.

Cities rise on it, roads stretch on it, dams restrain rivers with it, ports and runways endure decades of abuse because of it. When concrete is reinforced with steel, it becomes the quiet workhorse that allows civilisation to stand, quite literally, at scale.

What makes concrete so indispensable is not sophistication but reliability. It performs exceptionally well under compression, is relatively cheap to produce, can be poured and shaped almost anywhere, and—once cured—can withstand decades of punishing use with minimal maintenance.

Concrete, like ammonia, steel, and plastics, is a reminder of Smil’s central theme: civilisation is built from heavy, energy-hungry materials that do not bend to narratives. Progress begins by understanding them clearly, not pretending they are optional.

A concrete problem

Concrete feels eternal. Once poured, it looks immovable, inert, done. But that perception is misleading. Ordinary construction concrete is not inherently durable in the way stone is. It is vulnerable to water infiltration, freeze–thaw cycles, chemical attack, corrosion of embedded steel, thermal stress, and poor workmanship. Over time, these stresses accumulate.

• The scale of the problem is unprecedented. Between 1990 and 2020 alone, humanity poured nearly 700 billion tonnes of concrete into the built environment. That is an extraordinary act of material emplacement compressed into a single generation. And unlike stone monuments that weather over centuries, much of this concrete was designed for speed, cost efficiency, and short lifespans, not permanence.
• Smil’s warning is about what comes next. Concrete doesn’t disappear when it fails. It crumbles, cracks, spalls, and corrodes, imposing costs long after the original construction boom has faded from memory. The 21st century, he argues, will be defined not just by building, but by repair, replacement, demolition, and abandonment on a scale humanity has never faced before.

The United States already offers a preview. Its infrastructure—much of it built during mid-20th-century expansion—has aged poorly. The latest national infrastructure report card assigns poor to very poor grades across concrete-dominated systems, with dams, roads, and aviation infrastructure receiving Ds and an overall average of D+. These are not aesthetic failures; they are safety risks, economic drains, and compounding maintenance liabilities.

China’s situation, Smil suggests, could be even more severe. Its rapid, large-scale construction since the 1990s dwarfs anything previously attempted. As those structures age simultaneously, the financial, logistical, and environmental burden of maintaining or replacing them by mid-century will be immense.

The price of progress

Smil writes: “Requirements for fossil carbon have been—and for decades will continue to be—the price we pay for the multitude of benefits arising from our reliance on steel, cement, ammonia, and plastics.”

The key word in Smil’s sentence is reliance. These materials are not optional add-ons to modern life. They underpin food security, shelter, transport, healthcare, and infrastructure at planetary scale. Remove or sharply restrict them without fully equivalent substitutes, and the benefits they enable—abundance, longevity, mobility, resilience—collapse with them.

Smil is also making a temporal argument. Even with aggressive innovation, efficiency gains, and partial substitutions, these systems cannot be rebuilt overnight. Industrial plants last decades. Supply chains evolve slowly. Capital stock has inertia. For “decades,” as he puts it, fossil carbon will remain embedded in the foundations of civilisation.

This framing matters because it reframes the climate and sustainability debate away from absolutism. The real question is: How do we reduce the price we are paying—gradually, intelligently, and without breaking the systems that keep use alive and comfortable?

The global melting pot

Smil treats globalisation not as an ideology or a slogan, but as a material fact of daily life—so ordinary that we rarely notice it. It manifests itself in the banal details of existence: the phone assembled in one country with components from a dozen others, food grown continents away, software written across time zones, medicines whose supply chains span the planet. Globalisation is not something we occasionally engage with; it is something we live inside, continuously.

Four phases of globalisation

Smil traces the history of globalisation in four distinct phases.

1. Wind-Driven Globalisation: This was globalisation at the mercy of biology and weather. For millennia, goods moved primarily by human and animal muscle, with occasional assistance from wind. Caravans advanced at roughly 25 kilometres per day; ships sailed at around 4 kilometres per hour when conditions allowed. Trade routes linked distant regions—Indian goods reached the Mediterranean, Chinese silk arrived in Rome—but journeys took months or years and often failed entirely. This system worked, but barely. It was slow, fragile, selective, and elite. Only high-value, low-volume goods justified the risk and time involved. As Smil puts it, this was “… incipient, selective, and limited globalization.” The world was connected, but tenuously.
2. Steam Engine and Telegraph-Driven Globalisation: This phase marks the first true acceleration. Two breakthroughs mattered enormously. First, accurate navigation at sea became possible after the invention of reliable marine chronometers by John Harrison, which solved the longitude problem. Second, steam power began to replace wind. By the late 1830s, steamships entered commercial service, and over the next decades, they overtook sail as the dominant mode of propulsion. Paddle wheels gave way to screw propellers, enabled by advances in steel production. At the same time, the telegraph transformed information flow. For the first time, merchants could respond to real-time knowledge of prices and demand across continents. Trade was no longer blind; it became coordinated. “For the first time in history, trading could take into consideration the knowledge of demand and prices in different parts of the world …” When this maritime revolution combined with the explosive spread of railroads after 1840—across Europe, North America, India, Asia, and Latin America—the effect was dramatic. Between 1870 and 1913, global trade volume quadrupled. This was the first wave of genuinely large-scale globalisation.
3. Diesel Engine, Flight, and Radio-Driven Globalisation: The early 20th century brought efficiency and reach. Diesel engines emerged as superior prime movers, gradually displacing steam due to higher efficiency and lower operating costs. Radio improved upon the telegraph by enabling faster, more flexible communication without fixed lines. And crucially, gasoline-powered aircraft introduced a completely new dimension: speed. People, mail, and high-value goods could now traverse vast distances in hours or days instead of weeks. This did not replace maritime trade, but it compressed time and reshaped expectations. Globalisation became not just wider, but faster and more responsive.
4. Turbines, Containers, and Microchip-Driven Globalisation: This is the phase we still live in. After the 1950s, several technologies converged. Diesel engines became even more efficient. Turbine engines enabled reliable intercontinental air travel. Containerisation revolutionised shipping by standardising cargo, slashing loading times, reducing theft, and dramatically lowering costs. And the microchip transformed coordination, computation, finance, logistics, and communication. “The integration of the global economy has been closely tied to the introduction of wide-body jetliners—to the Boeing 747 and to its later Airbus (A340 and A380) emulators.”

Together, these changes made globalisation routine, massive, and invisible. Supply chains stretched across continents with clockwork precision. Information moved at near-zero marginal cost. Trade volumes exploded not because humans suddenly wanted to trade more, but because the friction had been engineered out of the system.

China, India, Russia

In the early decades of the most recent phase of globalisation, the primary beneficiaries were Western economies, especially the United States. The West already possessed capital, advanced technology, managerial expertise, and institutional frameworks capable of exploiting containerisation, jet transport, computing, and global finance. Globalisation initially amplified advantages that were already in place.

But over the last three decades, the centre of gravity has moved. The largest gains from globalisation have accrued not to the West, but to China, followed by India and Russia. This was not accidental, nor purely the result of market forces. It happened when technical capacity and financial access aligned with decisive political reversals.

In China’s case, this meant opening markets, welcoming foreign capital, investing relentlessly in infrastructure, and integrating itself into global manufacturing networks while maintaining tight political control. India’s gains followed economic liberalisation in 1991, demographic momentum, and the gradual integration of services and skilled labour into global markets. Russia’s trajectory was more uneven, shaped by resource exports and geopolitical constraints, but still deeply tied to global energy and commodity flows.

Globalisation is not inevitable

Smil’s argument here is a corrective to the idea that globalisation is a one-way ratchet driven automatically by technology.

Yes, technical advances in transport, energy, and information enable globalisation—but they do not guarantee it. History makes this clear. The first half of the 20th century saw a pronounced retreat from economic globalisation despite the presence of steamships, railways, and telegraphs. Political choices, wars, protectionism, and social upheaval overrode technical capability. Technology opens doors; it does not force societies to walk through them.

This is why Smil stresses that the post-1990s acceleration of globalisation—especially for countries like China and India—was not preordained. It required political liberalisation, institutional reform, social adaptation, and strategic intent, alongside energy access and capital. Without those reversals, the same technologies would have produced far more modest outcomes.

At the same time, Smil resists the opposite fantasy: that globalisation can be quickly or cleanly undone. Too much has been structurally locked in. Many countries depend heavily on food imports. No major economy is self-sufficient in all critical raw materials. Supply chains have been optimised over decades. Instant reversals are simply not practical, and abrupt disruptions come with steep economic and human costs. “A mass-scale rapid retreat from the current state is impossible, but the pro-globalization sentiment has been weakening for some time.”

What history suggests instead is asymmetry: A rapid, total collapse of globalisation is unlikely. A gradual weakening, rebalancing, or partial retreat is entirely plausible.

This erosion has been underway for some time. Concerns about resilience, national capacity, and strategic dependence did not begin recently. Arguments for restoring domestic manufacturing, diversifying supply chains, and reducing exposure to distant shocks have circulated for years.

Global trade and integration may no longer race toward ever higher peaks. Instead, we may be living through the crest of globalisation, followed by a long, uneven ebb—one measured not in months or years, but in decades.

Globalisation is not destiny. It is a historically contingent arrangement—durable in parts, vulnerable in others—and subject to revision as societies renegotiate the balance between efficiency, resilience, and sovereignty.

Risks of living

Next Smil moves on to talking about risk. Specifically the risk of death, because “… the finality of dying provides a universal, ultimate, and incontestably quantifiable numerator that can be used for comparative risk assessment.”

His reasoning is straightforward. Risk is notoriously hard to compare across domains because harms vary in kind—injury, illness, inconvenience, financial loss, psychological distress. But death has a unique property: it is final, universal, and unambiguous. You can argue about severity, quality of life, or long-term effects, but you cannot argue about whether someone is alive or not. That makes mortality the cleanest possible metric for comparative risk assessment.

To make risks comparable, Smil standardises the denominator at 100,000 people. In other words, for any given activity, exposure, or hazard, he asks: Out of every 100,000 people, how many can be expected to die from this specific cause over a defined period?

Of course, when it comes to risk, even the risk of death, “… the world is full of constant or episodic risks, but it is also replete with wrong perceptions and irrational risk appraisals.” The world is indeed full of risks, some constant and some episodic. We are exposed daily to small, cumulative dangers (diet, inactivity, air pollution), and occasionally to dramatic, concentrated ones (accidents, disasters, pandemics). But layered on top of these real risks is a second, equally powerful force: systematic misjudgment.

Humans are not neutral processors of probability. We overweight risks that are: sudden rather than slow, dramatic rather than mundane, involuntary rather than chosen, unfamiliar rather than routine, amplified by media rather than experienced personally.

As a result, we routinely fear the wrong things and ignore the right ones. Rare events that kill few people can dominate public consciousness for years, while everyday behaviours that quietly kill millions are treated with indifference.

Specially noteworthy is the asymmetry between voluntary (risks that people knowingly undertake like base jumping or driving) and involuntary risk (risks that are imposed on people like that of being caught in a terrorist attack in a busy market or catching a novel virus while visiting a foreign nation for official business).

The mechanism is psychological, not rational. Control substitutes for probability. When we believe we are in charge, fear recedes. When control is removed, fear fills the gap—regardless of the numbers. This is why societies can accept enormous mortality from road accidents or lifestyle diseases while reacting with panic to rare but imposed dangers like a terrorist attack.

Smil’s point is not that involuntary risks should be ignored. Ethical governance rightly treats imposed risks more seriously because consent matters. But the mismatch becomes problematic when it leads to grossly disproportionate responses—diverting attention, resources, and policy focus away from risks that actually kill far more people. Understanding how the world really works requires resisting the comforting illusion that what feels safe is safe—and that what feels terrifying is necessarily deadly.

This asymmetry between voluntary and involuntary risk perception has made researchers argue that there is no such thing as purely objective risk.

• On the one hand, risks can be quantified. Deaths per 100,000 people is a real number. Bodies count the same everywhere. From that perspective, risk appears objective. But on the other hand, how those numbers are interpreted, tolerated, or acted upon is deeply subjective.
• Risk perception is shaped by familiarity. Known dangers—driving, household accidents, seasonal illness—fade into the background even when they are statistically significant. New or unfamiliar risks, especially those involving novel technologies or pathogens, trigger heightened anxiety precisely because people lack experience-based intuition. Uncertainty amplifies fear, “Feelings of dread play an outsized role in risk perception.”
• Risk perception is also shaped by culture. Different societies normalise different levels of danger depending on history, values, trust in institutions, and social narratives. What feels intolerable in one context may feel routine in another. The same numerical risk can provoke outrage in one country and indifference in another.

Smil’s point is not to abandon measurement, but to recognise its limits. Numbers tell us how often harm occurs; they do not tell us how humans will respond to that harm. Policy debates that pretend risk is purely objective miss this reality and are blindsided when public reactions diverge sharply from statistical expectations.

In both cases, the failure was not in the data but in the assumption that numbers alone settle the question. Risk management is not just about calculating probabilities; it is about anticipating human response.

Human flaws

Our perception of risk is deeply rooted in our evolutionary history, and it was shaped for a world very different from the one we inhabit today. For most of human evolution, survival depended on rapid, intuitive judgments, not on statistical reasoning. Natural selection favoured brains that could: react quickly to immediate threats, prioritise vivid/emotionally salient dangers, and err on the side of caution when outcomes were uncertain.

This produced a cognitive system that is excellent at dealing with acute, visible, short-term risks—predators, hostile humans, sudden environmental threats—but poorly suited for abstract, probabilistic, long-term dangers.

Several evolutionary mismatches follow from this:

• Salience over probability: Our brains respond more strongly to dramatic events than to frequent ones. A rare but shocking danger triggers more fear than a common but dull one, even if the latter is far deadlier.
• Control bias: We evolved to trust risks we actively manage (hunting, climbing, fighting) more than risks imposed by others. Feeling “in control” suppresses fear (technically, not just “control,” but perceived agency + familiarity + skill), regardless of actual danger.
• Novelty bias: New threats provoke disproportionate anxiety because we lack ancestral experience with them (or more accurately, a predictive model). Familiar dangers fade into the background, even when statistically lethal.
• Immediate harm over delayed harm: Evolution rewarded attention to threats that could kill you now. Slow, cumulative risks—like chronic disease or environmental exposure—barely register emotionally.

In the ancestral environment, these biases were adaptive. In the modern world, they might become liabilities. We fear plane crashes more than car accidents, terrorism more than cardiovascular disease, rare technological failures more than everyday behaviours that quietly shorten lives.

Smil’s contribution is to show how this evolutionary wiring collides with modern complexity. Industrial society produces risks that are diffuse, indirect, delayed, and mediated by systems we don’t directly observe. Our instincts did not evolve to assess deaths per 100,000 people; they evolved to detect rustling in the grass.

Here is a short list of things that keep tripping us up, even though rationally we might know they are to be avoided.

• First, there is the asymmetry I’ve already noted: we routinely underestimate voluntary, familiar risks and exaggerate involuntary, unfamiliar ones. Driving fast feels acceptable; a rare external threat feels intolerable. Familiarity breeds complacency, not safety. This is why people tolerate behaviours that statistically shorten their lives while obsessing over risks that barely register in mortality data.
• Second, even when risks are cheap and easy to reduce, many people don’t bother. Installing smoke detectors, wearing seat belts consistently, improving home safety—these are low-cost, high-impact interventions. The failure here is not ignorance; it is inertia and psychological discounting. If a danger isn’t immediate, visible, or emotionally charged, it struggles to command attention.
• Third, societies—governments included—are notoriously bad at dealing with low-probability, high-impact events, such as pandemics. These threats sit in an uncomfortable cognitive zone: too rare to feel urgent, too severe to plan for casually. Preparing for them looks wasteful in quiet years and inadequate in crisis years.
• Fourth, when catastrophic events do occur, the lessons we draw from them are often emotionally amplified rather than rationally calibrated. We exaggerate the likelihood of recurrence and treat the event as uniquely defining, even when its cumulative human and economic toll is comparable to—or smaller than—other risks we accept quietly year after year. Smil’s makes deliberately jarring comparison here: during the second decade of the 21st century, approximately 125,000 Americans were killed by guns, while around 170 died in terrorist attacks. Yet terrorism dominated political discourse, media coverage, and public fear, while gun deaths were normalised into the background noise of everyday life. The discrepancy cannot be explained by numbers. It can only be explained by dread.

This is Smil’s central diagnosis: public reaction to risk is driven less by comparative outcomes and more by fear of the unfamiliar, the uncontrollable, and the poorly understood. When strong emotions are involved, people fixate on the mere possibility of a dreaded outcome and lose sight of its probability. Risk becomes a narrative problem rather than a numerical one.

What should we really worry about

So, is there nothing we should worry about? Are all concerns exaggerated? No, the things one should be concerned about fall in two categories by my logic.

• First is the small impact but high frequency risks, such as air pollution. Any single exposure is unlikely to be catastrophic. Breathing polluted air on one bad day will not kill you. Eating poorly for one week will not undo your health. Sitting too much today will not cripple you. The risk of truly disastrous consequences from any one instance of exposure of these kinds of risks is tiny, almost negligible. But over time, it all adds up. The best way to deal with these risks is by looking at your life and gradually eliminating the causes of such risk before they reach the tipping point, for example, finding a job in a city with better air quality. Smil would say this is where rational concern pays dividends: act early, act quietly, and let compounding work in your favour instead of against you.
• The second category is risks that are rare but will wipe you out if they do occur, like being involved in an airplane crash. Beyond maintaining a modicum of probabilistic fluency of the true chance of such risks, there is little one can do here, because if they happen to you, you will likely not get a second chance. If you do find yourself in the middle of such an unfortunate situation, trying and hoping for the best is usually the only option. The probability is vanishingly small, but the consequence is total. Here, anxiety is largely useless. Beyond maintaining a basic understanding of how unlikely such events actually are, there is little to optimise. You cannot meaningfully “prepare” for a once-in-a-lifetime catastrophe that allows no second attempt.

The broader lesson is that mature risk management is selective, not reactive. Focus on risks that compound quietly and can be reduced through deliberate choices. Refuse to let rare, uncontrollable catastrophes dominate your mental life simply because they are vivid or frightening.

Waste less, want less

No one is going to Mars anytime soon. Not at scale. Not in a way that meaningfully relieves pressure on Earth. Not as a civilisational fallback. For all practical purposes—measured in decades and likely centuries—Earth is the only habitable system we have. Every serious discussion about the future has to start from that constraint, not from speculative exits.

Once you accept that premise, attention shifts from fantasies of escape to the conditions that make Earth livable in the first place. Smil aligns closely with the planetary-boundaries framework when he points to nine interlinked categories of threats to habitability. These are not abstract concerns; they are system-level stresses that accumulate, interact, and reinforce one another.

Among them, several deserve particular emphasis:

• Climate change: Not because it is the only problem, but because it acts as a force multiplier—altering weather patterns, stressing ecosystems, amplifying water scarcity, and destabilising food systems.
• Interference in nitrogen and phosphorus cycles: Largely driven by fertiliser overuse, this disrupts soils, waterways, and coastal ecosystems, linking food production directly to environmental degradation.
• Freshwater depletion and excessive use: Aquifers recharge slowly, rivers are overdrawn, and climate variability intensifies scarcity. Water stress is already a binding constraint in many regions.
• Adverse land-use changes: Deforestation, soil degradation, urban sprawl, and habitat fragmentation reduce the planet’s capacity to regulate climate, store carbon, and support biodiversity.
• Biodiversity loss: Often treated as an aesthetic or moral issue, but in reality a functional one: ecosystems lose resilience as species disappear, making failures more likely and recovery harder.

The remaining threats—ocean acidification, stratospheric ozone depletion, atmospheric aerosols, and chemical pollution—complete the picture. Some are better managed than others (ozone depletion is a rare success story), but none can be ignored indefinitely.

Smil’s deeper point is systemic: habitability is not threatened by one dramatic event, but by cumulative pressure across multiple dimensions. Focusing obsessively on a single issue while neglecting others is a mistake. These boundaries interact. Push too hard on enough of them, and the system shifts into states that are difficult—or impossible—to reverse.

No backup planet

This brings the argument full circle. If Earth is all we have, then responsibility is not optional. Not in the moralistic sense, but in the practical one. There is no backup planet, no reset button, no technological deus ex machina waiting just over the horizon.

First, a clarification that often gets lost in public discourse: we are not about to run out of oxygen. Neither fossil fuel combustion nor forest fires pose any meaningful threat to atmospheric oxygen levels at planetary scale. That fear belongs more to science fiction than to Earth-system science. Oxygen is not the bottleneck. Freshwater availability and food production are.

Both are already under stress in many regions, and both are strongly influenced by climate change. Rainfall patterns shift, glaciers retreat, droughts intensify, floods become more erratic, and heat stress affects crops and labour. Climate change does not uniformly reduce food production everywhere—some regions may benefit temporarily—but it increases volatility and uncertainty, which is far more damaging to large-scale systems than slow, predictable change.

Here is the central irony Smil wants us to confront: the same fossil-fuel dependence that enabled modern food abundance is also the primary driver of climate change that now threatens that abundance. This is not a moral paradox; it is a systems dilemma.

Anthropogenic climate change is driven overwhelmingly by greenhouse gases, with carbon dioxide (CO₂) and methane (CH₄) doing most of the work. Since the 1800s: CO₂ accounts for roughly 75% of human-caused warming. Methane contributes about 15%.

• CO₂ comes primarily from fossil fuel combustion and cement production—two pillars of modern civilisation. Methane, by contrast, comes largely from agriculture and waste: rice paddies, ruminant livestock (yes, digestion), and landfills.
• The concentration changes are stark. Before industrialisation, atmospheric CO₂ hovered around 270 parts per million. By 2020, it had risen to about 420 ppm. Methane increased even more dramatically in relative terms, from about 800 parts per billion to roughly 1,800 ppb over the same period.
• Methane matters disproportionately because of its warming potency. Molecule for molecule, releasing one unit of CH₄ has the same warming effect as releasing 28–36 units of CO₂ over a 100-year period. The gases absorb outgoing infrared radiation differently, making methane far more effective per unit—even though it is present in much smaller concentrations.

Smil argues that much public coverage of global warming has drifted away from careful explanation toward sensationalism. Facts are often poorly communicated, uncertainties are blurred, and projections are presented with a tone that veers into the apocalyptic. Over time, this does real damage. When every forecast is framed as the end of the world, credibility erodes. People either panic briefly and then tune out—or they harden into scepticism.

Neither response leads to sustained, intelligent action. “… coverage of global warming has been replete with poorly communicated facts, dubious interpretations, and dire predictions, and over time it has definitely acquired a distinctly more hysterical, even outright apocalyptic flavour.” Smil’s concern is not that climate change is trivial. It is that hysterical framing undermines rational response. Serious, long-term problems require patience, trust, and policy continuity. Apocalyptic rhetoric produces the opposite: fatigue, polarisation, and the temptation to reach for symbolic gestures instead of effective measures.

This sets up his second, more uncomfortable observation. When you look honestly at where actual, large-scale reductions in carbon intensity have come from so far, they have not been driven primarily by grand climate policies or moral crusades. Instead, they have emerged as by-products of broader technical and economic shifts: improved efficiency, better management practices, changes in fuel mix driven by cost and reliability, and incremental innovation whose original motivation had nothing to do with reducing greenhouse gases.

Even the much-celebrated rise of renewable electricity illustrates Smil’s caution. While the installation of solar PV panels and wind turbines has expanded rapidly, its global impact has been overwhelmed by rising emissions elsewhere, particularly in China and other parts of Asia. Electricity demand has grown so fast—driven by industrialisation, urbanisation, and rising living standards—that renewables have often added capacity rather than displaced fossil fuels at scale.

The result is a sobering paradox: visible progress in some regions coexists with accelerating emissions globally. This does not mean renewables are useless. It means their deployment, so far, has not been sufficient to counterbalance the sheer growth of energy use in developing economies.

At the most basic physical level, global warming is about imbalance. Because of rising concentrations of greenhouse gases, Earth is now re-radiating slightly less energy than it receives from the sun. That small mismatch, sustained over decades, accumulates. It warms oceans, air, land, and ice. Nothing dramatic is required; persistence is enough.

What makes this imbalance so hard to correct is that many of our own choices—often made for comfort, convenience, or economic growth—quietly amplify it.

Smil points out that while we talk endlessly about decarbonisation, we have simultaneously promoted diffusion of energy use in ways that lock in higher fossil-fuel consumption. Two examples are especially revealing.

• First, buildings. In cold climates, poor building codes and lax retrofitting standards have been a massive, long-term failure. Proper insulation, triple-glazed windows, and high-efficiency heating systems are not futuristic technologies; they are mature, well-understood solutions. Once installed, they deliver energy savings for decades. And yet, millions of buildings continue to leak heat year after year, turning avoidable energy waste into permanent emissions.
• Second, the global embrace of SUVs. The average SUV emits about 25% more CO₂ annually than a standard car. Multiply that by roughly 250 million SUVs on the road by 2020, and the scale becomes unavoidable. This single consumer preference has wiped out—several times over—the emissions reductions achieved through the gradual spread of electric vehicles during the 2010s, especially when you factor in heavy industry, trucking, and aviation, where electrification remains limited.

Smil’s point is not to single out villains, but to highlight systemic inconsistency. We celebrate marginal gains in one area while massively expanding demand in another. The net effect is predictable.

This is why Smil is sceptical about the real-world impact of decades of international climate conferences. These meetings were never capable of stopping China’s industrial expansion, reversing global consumer preferences for larger vehicles, or preventing millions of families across monsoonal Asia from buying air conditioners to survive hot nights. These are not ideological choices; they are material responses to development, heat, and aspiration.

The numbers tell the story. Between 1992 and 2019, global CO₂ emissions rose by about 65%, while methane emissions increased by roughly 25%. Despite agreements, declarations, and targets, the trajectory did not bend downward.

Smil’s conclusion is not cynical, but sobering. Global warming is not stalled by lack of awareness or conferences alone. It is driven by billions of small, rational decisions interacting with massive systems. Any solution that ignores everyday energy use, infrastructure quality, and consumer behaviour—while relying primarily on high-level declarations—will continue to disappoint.

Understanding how the world really works means recognising that energy efficiency quietly beats grand ambition, and that durable progress comes from fixing the boring, structural things we keep postponing.

He acknowledges uncertainty—all projections carry margins of error—but argues that the balance of evidence points in one direction: limiting warming to 1.5°C now appears extremely unlikely. Not impossible in a mathematical sense, but implausible given observed emissions trajectories, infrastructure inertia, and the pace at which real systems change. In his metaphor, the horse has probably already left the stable.

Smil’s frustration is aimed squarely at pathways to “net zero” that rely on wishful arithmetic: assumptions about unprecedented rates of deployment, perfectly coordinated global action, frictionless technological substitution, or vast negative-emissions capacities that do not yet exist at scale. These models often look elegant on paper precisely because they abstract away the hardest parts—capital stock turnover, supply-chain limits, material constraints, political realities, and human behaviour.

Show the work

What Smil insists on is realism about embeddedness. Energy and material systems are not modular apps you uninstall and replace. They are deeply woven into food production, housing, transport, healthcare, and industry. They operate at enormous scale, across decades-long lifespans, and under wildly unequal global conditions. Ignoring that complexity does not accelerate progress; it produces targets that collapse on contact with reality.

His challenge, then, is directed at anyone proposing a preferred future path: Show the work. Explain how transitions will occur within known physical limits, economic costs societies can actually bear, and timelines consistent with infrastructure replacement rates. Do not substitute aspiration for mechanism. The deeper implication is uncomfortable but clarifying. If 1.5°C is likely gone, then clinging to it rhetorically may be counterproductive. It risks turning climate action into a moral purity test rather than a practical exercise in harm reduction, adaptation, and resilience.

• The first constraint is scale and inertia. Carbon-dependent activities are not marginal add-ons to modern life; they are the backbone of food systems, housing, transport, industry, and healthcare. These systems were built over generations, with enormous sunk costs and long-lived infrastructure. Expecting to eliminate all of them within a few decades ignores how slowly capital stock turns over and how tightly these activities are coupled to one another. Looking ahead, Smil urges a return to critical scrutiny of models, especially those that smooth away environmental, technical, economic, and social complexity in order to produce comforting trajectories.
• The second constraint is equity and realism. There are no swift, universal, and affordable solutions to challenges like tropical deforestation, biodiversity loss, soil erosion, or climate change. Non-carbon energy could theoretically displace fossil fuels within one to three decades—but only under conditions most societies would not accept: sharp reductions in living standards across wealthy nations and the deliberate denial of material improvement to billions of people in Asia and Africa. Smil is blunt about this trade-off. Any plan that pretends otherwise is not ambitious; it is evasive.
• The third issue is where attention is being misplaced. Practical solutions exist—incremental efficiency gains, better land use, reduced waste, improved building standards, dietary moderation, adaptive infrastructure—but they are often mundane. They lack drama. As a result, they rank low in public narratives dominated by visions of sweeping “low-carbon revolutions” that depend on technologies not yet available at scale: near-perfect grid storage, massive negative-emissions systems, or permanent underground carbon sequestration deployed globally without friction.

Smil does not deny the potential of innovation. He challenges the habit of substituting future miracles for present discipline. The final note is about resolve. The question is not whether solutions, adjustments, and adaptations exist—they do. The question is whether there is sufficient global will to pursue the ones that are non-magical, gradual, politically difficult, and costly. History suggests that societies prefer promises of painless transformation to the reality of steady, constrained improvement.

Smil’s realism is not pessimism. It is a refusal to confuse hope with fantasy. If progress is to be made, it will not arrive as a breakthrough that dissolves trade-offs. It will come through accumulation: of small efficiencies, restrained choices, better maintenance, and adaptive resilience. Slower than we want. Costlier than we admit. But grounded in how the world actually works.