Book Review: Energy and Civilization

What is fueling the engine of progress, and for how much longer?

Daniel Issing
10 min readApr 15, 2021

There is probably no more famous formula in physics than E = mc ². It is arguably the one mathematical statement (Pythagoras’ theorem being the only real contender) that has made its way into popular culture. It’s no exaggeration to say that Einstein’s arguments, which led him to postulate the fundamental equivalence of energy and matter above, have revolutionized physics. In Energy and Civilization: A History, environmental scientist Vaclav Smil (who counts Bill Gates among his loyal followers) proposes to derive a similar relationship between energy and what we’ve come to call civilization: culture, infrastructure, economic development and other human achievements. To simplify somewhat, the more energy a tribe, a nation or an empire has access to, the more highly developed it will be. The devil, of course, is in the details.

That energy drives civilization is a truism that hardly seems to merit a 500+ pages tome filled with numerous graphs, calculations and endnotes. On the most basic level, life cannot be sustained without energetic input, and evidently it doesn’t stop there. A moment’s reflection will no doubt bring countless examples of activities to mind that could not exist without massive supplies of cheap, controllable energy. The ubiquitous role that electricity plays in the developed world, and its relative absence in poorer countries, is one clear example of the transformative power of energy (no pun intended!). So what’s the substantive disagreement with existing theories that made Smil write the book?

He doesn’t really come out openly and say “here are the sixteen theories that are typically advanced to explain the rise and fall of civilizations, let me show you why they are all wrong”. In general, he spends rather little time to contrast his views with those of other historians, so it’s a little hard to see what the alternatives are. I can think of several potential challenges (not exhaustive):

  • One obvious problem with the equation more energy = more wealth is the existence of resource-rich countries that nevertheless stay desperately poor (think Venezuela). If availability of energy sources were the sole determinant of a nation’s fate, this is puzzling.
  • There’s a hen-and-egg problem with respect to the relationship of energy and ideas. Good ideas lead to better technology, which leads to more efficient use of energy, which breeds again more ideas how to exploit resources more fruitfully. What is cause, and what is effect?
  • Institutions seem to matter a great deal. Energy could be used to produce goods for the masses, support medical research and other noble ventures, or it could be monopolized for pointless feuds and warfare.
  • Finally, it might be a temporal phenomenon. Activities that could be seen as high marks of civilization (say, reading the classics) require far less energetic input that common past-times such as flying to Tanzania for a jeep safari. It is at least conceivable that the two could decouple.

Rather than addressing those points directly, Smil opted to go all the way back to the prehistoric days of our species and show in painstaking detail how each and every advance in our cultural evolution can be attributed to the widening of some energetic bottleneck. Once you’ve made yourself through them, it’s difficult not to see the world through these lenses. So let’s have a look at some examples.

No discussion of the history of civilization would be complete without looking at the transition from hunter-gatherer societies to sedentary cultures. In fact, the very word “civilization” is typically identified with the beginnings of agriculture, and nomadic tribes were routinely depicted as prime examples of uncivilized people. Quite apart from any normative judgements, it is a rather puzzling fact that it arose at all, considering that homo sapiens was doing just fine for most of its history without it. Even stranger is discovery that when it finally did arise, it did so independently in many different places within a relative short time frame. Can energy be the explanation?

In Against The Grain, James Scott offers a radical thesis for the dawn of agriculture: Rather than being emerging from the bottom up, as a superior approach to ensure adequate nutrition, he argues that it was actively fostered by local elites because it made exercising and amassing power so much easier. In particular, they welcomed the shift from a varied diet of hunted game and foraged plants to one that heavily relied on grain, which its unique advantages of being easy to store and divide — and hence, to become a veritable source of taxation. State formation and sedentarism go hand in hand.

I’ve picked this example because it is representative of many similar debates that form the core of Energy and Civilization. To cast it in the most general terms, the big question is whether history is essentially materialist (i.e. changes in environmental conditions precede culture adaptations) or idealist (i.e. ideas — both in the technological and the normative realm — are the prime movers in history). Smil is firmly on the materialist side: Agriculture came about because of a combination of population growth and environmental stress after the last ice age, in accordance with standard scholarly opinion(?).

This is already starting to look like a fantastically pointless debate, much like the very similar nature-vs-nurture debates in evolutionary biology. Imagine the head of a tribe in the fertile crescent ca. 9500 BC, roaming an area that is increasingly seeing long dry seasons. These climatic changes make certain plants like tubers (edible part in the soil, an annual life cycles) a more energetically appealing option than it had been before. The number of his fellow foragers has been increasing steadily, and the old hunting grounds just aren’t what they used to be anymore. Should they switch over to a more settled way of life? Of course, to ask the question is to answer it; it’s not like the chieftain has been waiting for the right conditions to pursue alternative strategies. The vast agricultural knowledge needed to grow tubers successfully did not just spring up overnight. Domestication can only happen after people figured out how to collect and plant wild seeds themselves, which in turn depends on an immense array of folk biological knowledge. To be able to adapt to changing circumstances, ideas about alternative techniques must already be available, and these don’t come into being by mere happenstance. Mind and matter are intertwined in complicated ways, and singling out any one of them as the ultimate determinant of history is doomed to fail.

Having said this, there is a great deal to be learned from taking a closer look at energy expenditures. A history of thought cannot explain why farmers so often behaved like gamblers, harvesting just enough to get by on (with droughts, floods and pests regularly wreaking havoc), how wolves came to be domesticated (the growing availability of starches in the diet was a boon to a genetic variant that also happened to be more docile, the ancestors of modern dogs), why horses became the dominant working animal (high raw energy output and endurance), or why much of human history fits very well into the Malthusian framework (the labor contributions of new offspring were much more valuable than its energetic costs in terms of pregnancy and upbringing, even though this led to socially undesirable overpopulation). There are many more examples like this in the book, and Smil is only too happy to put a number on them. This can sometimes be a little dull and hard to keep in memory (how much work has to be performed by a woman irrigating a 10 ha field with a bucket filled from a well some 5 km away?), and I wish he had found a more intuitive way to put those things in relation. At the same time, if you’re anything like me, you probably had no idea what orders of magnitude we are talking about in terms of work performed for even the most mundane of activities, so I welcome his efforts as a necessary corrective.

Humans did not remain farmers forever, and the transition towards a wider mix of occupations could not have happened had it not been for the exploitation of additional prime movers. Cities, states and empires formed after humans learned to command the elements, such as water or wind. The efficiency of windmills and waterwheels compares poorly to our modern standards, but it was an enormous step forward for supplying an ever-growing population with crops planted and processed by a declining agricultural sector. A case study of horse power shows how many non-human sources of energy were synergetic: Paved roads were only a first step to ease the transportation of goods by carriages. The construction of canals allowed for a tenfold increase in the load pulled by horses. And even competing means of transportation (such as trains) did not, at first, diminish their importance. In fact, “peak horse” occurred during the railway age, because horses became indispensable for distributing goods and transporting passengers once the train had arrived at its destination.

Indeed one is confronted again and again with observations how comparatively recent we transitioned away from certain sources of energy. It took until the end of the 19th century for advanced nations such as France and the US derived most of their energy supply from fossil fuels. Sperm whale blubber remained the material of choice for indoor lightening in rural areas until about the same time. And horses? The German invasion of Russia during the Second World War, probably the archetypical example of tank-heavy military campaign, was supported by more than half a million ungulates.

Warfare, unsurprisingly, plays a major role in the book. The maximum destructive power that could be wielded by the available weapons of the age certainly has to be factored in when trying to analyze whether our species has become more violent or more peaceful, as (among many others) Steven Pinker has done in The Better Angels of our Nature. World War II no doubt was a horrendous calamity because of the many terrible ideas over which it was fought, but at the same time, it is hard to imagine a similar death toll arising from a clash of medieval armies, fighting by and large with hand-held weapons. Not only this, but also the supply train was considerably slower to nonexistent, which put important limits on the ambitions of even the most ferocious general.

Waterwheels, windmills and horses have long lost their prominence in supplying civilization with energy. Ours is the age of electricity, which the old prime movers just don’t supply consistently enough, not to speak of the meagre quantities they output. Most of it comes from fossil fuels (around 86%, down from 90% in 1990), and Smil spends a great many pages to highlight the improvements in conversion rates, the principal techniques available (coal, gas, oil, nuclear, renewables), and the numerous devices and gadgets that eventually consume the electricity. Right around here, the book reaches its lowest point, offering little more than a chronological listing of well-known technological breakthroughs that doesn’t ever seem to end. In addition to making the reading a real slog, it’s easy to lose sight of the forest among all those trees. This is even less excusable when the forest can be said to be the single most important event in human history. For example, compare this graph for global energy use

with the changes in per-capita GDP over the course of the last two hundred years:

Or better yet, the same graph over a period of 2,000 years:

Something absolutely remarkable has happened here, and energy consumption plays a fundamental role in it. The roughly 15-fold increase industrialized countries closely follows a similar explosion in these nations’ economic development. This should not really be surprising to anyone: Reliance on inanimate sources of energy freed up human labor, opened up the backcountries, enabled international trade and allowed to spatially and temporally separate the production (harvesting, if you prefer) of energy from its consumption. It has lifted billions of people out of poverty, allowed for education to become universally available in all but the poorest countries, slashed infant mortality by a factor of ten, and enable use to eradicate several deadly diseases. All of this would be a wonderful story if it wasn’t for one important caveat: Is it sustainable? Is it conceivable that those born in dire conditions will one day enjoy the same standards of living as today’s Western nations, or will Malthus’ demon rear its ugly head again? Not only climate change threatens the viability of the modus operandi, but also many other adverse ecological effects, plus the possibility of resource exhaustion (which, although often exaggerated, is a real threat that kicks in once the cost of extracting a raw material becomes prohibitively large).

So what next? Smil does not make any suggestions or policy prescriptions, but instead offers a healthy dose of skepticism. One the one hand, he repeatedly stresses that there is really no way around a transition away from fossil fuels, if not in the coming decades then certainly in the centuries to come. At the same time, he is fairly pessimistic about the possibility of renewables taking over.

There are areas that offer some form of hope. In highly advanced countries, energy consumption and GDP seem to be decoupling, and total primary energy consumption shows signs of levelling off :

Total energy consumption and energy intensity (serving here as a proxy for efficiency) for the United States, 1965–2019.

The problem is that it isn’t enough to break even. China and India, eager to reach the same standards of living for their population, are on a steady upward trajectory that shows no sign of slowing down, and other nations are likely to follow suit. What’s more, the levelling trend for rich nations is confounded by the tendency of those countries to offshore their energy-heavy production. Those who, like me, remain moderately optimistic that these challenges can be overcome by future generations, will find his book sobering, although the number of genuinely new insights is low. Recommended? Tough call. If you prefer something shorter, you may want to try his Energy. A Beginner’s Guide first, which is half as long and just as devoid of grand narratives.



Daniel Issing

Book reviews, trail running, physics, and whatever else I feel like writing about.