Energy and Civilization by Vaclav Smil Book Summary

Energy and Civilization, A History by Vaclav Smil


Canadian university professor Vaclav Smil’s legendary work on energy, particularly in the United States, has garnered worldwide honor. Yet Smil writes for experts, not the layperson. His energy overview covers 441 dense pages and oddly-sequenced chapters – plus addenda – relaying statistics, facts and expert opinion, but little softening storytelling. He describes the role of energy in societal issues, slavery, war, economic growth and environmental ruin. This brilliant work best serves determined readers pursuing encyclopedic knowledge of the history and role of energy from fire to fusion.


  • Without energy in one of its many forms, nothing gets done.
  • Energy conversion and use – including energy from the sun, wind and domesticated animals – enabled agriculture, which led to civilization.
  • Energy advantages in coal, steam, gas and oil explain much of the rise of history’s great empires. 
  • Energy is an essential component of history.
  • Without human ingenuity, most energy sources would be nearly useless.
  • A nation’s mastery of the latest, best sources of energy largely explains its wealth.
  • Wealthy nations’ waste of fossil fuels harms them and the Earth, while poor nations cause great damage by stripping forests for energy.
  • Renewable energies, though promising, may offer too little, too late.
Energy and Civilization Book Cover

Energy and Civilization Book Summary

Without energy in one of its many forms, nothing gets done.

All forms of life on Earth depend on energy. No human, animal, or natural or mechanical process can do anything without it. Humans’ ability to harness energy largely accounts for all advances in civilization.

“Energy is the only universal currency: One of its many forms must be transformed to get anything done.”

The efficiencies of myriad forms of energy differ greatly, and over the centuries, people strove to find more efficient ways to extract greater yield from energy sources and to obtain cleaner energy they could harness more easily. Energy optimization relies on learning, intelligence and governance conducive to innovation. The history of energy closely parallels the history of humanity.

Energy conversion and use – including energy from the sun, wind and domesticated animals – enabled agriculture, which led to civilization.

Standing erect allowed early humans to use their hands to manipulate tools, which required intelligence and caused the brain to grow in size and capacity. The smart use of tools, especially in hunting, led to the development of complex societies. Such advances enabled early humans to hunt and gather a more energy-intensive diet, including meats cooked and cured by fire – a critical energy discovery in the evolution of civilization. With evolved intelligence, collaborative skills and tools, people could hunt the animals that provided the most energy – large, fatty mammals like mammoth, bison and deer.

“All natural processes and all human actions are, in the most fundamental physical sense, transformations of energy.”

Frequent disease and periods of famine made life generally difficult and precarious for foraging tribes. The fortunate inhabitants of grassland areas in temperate zones near the oceans had an easier time hunting and harvesting wild plants. Sometimes their resources were sufficient to support more permanent and complex societies. 

Agriculture, including the domestication of animals, began about 10,000 years ago and led to the formation of gradually more complex societies that evolved into civilizations. The shift from foraging to planting was pivotal in history. The epochal shift from hunting to farming as a primary food source reveals a consistent human pattern of pursuing the best yields in exchange for the least energy expended within the limitations of local conditions. As soil quality and precipitation allowed, crop selection evolved toward plants that produced the highest energy yield, particularly those farmers could store and preserve with the least effort, such as cereals and corn.

Gradually improved agricultural methods sometimes yielded leftover energy supplies in the form of food. This enabled a more varied division of labor. Technological advances in plows, seeding and harvesting tools, plus the increased use of animals – oxen, buffalo and particularly horses – and the invention of better harnesses – upgraded farming efficiencies worldwide, though unevenly, over the thousands of years prior to mechanization.

Though plows and plow animals revolutionized agriculture in China, Egypt and Europe, the Mayans and the Aztecs achieved comparable yields without animals or plows. Like other agricultural societies, they relied on extensive irrigation, crop rotation and high-energy crops. Yet, varying weather patterns and natural disasters kept the specter of famine close through about 1900. In some parts of the world, especially where conventional farming remained the norm, deficiencies in food production – as opposed to war and other disruptions – caused malnourishment and famine well into the 20th century.

“No traditional agriculture could consistently produce enough food to eliminate extensive malnutrition.”

America’s farm productivity lagged behind Europe and China through the early 1800s until the mid-century adoption of better tools and techniques. By 1900, new methods in horse-driven plowing gave California the global lead and advanced the limits of modern farming. Despite impressive gains in yields worldwide in the 19th century, famines and malnourishment still plagued most civilizations. Human effort and animal-powered farming couldn’t sustain growing populations. In the 1920s, the arrival of mechanized farming powered by gas-burning engines transformed food production.

Energy advantages in coal, steam, gas and oil explain much of the rise of history’s great empires.

Improvements in water wheels, levers, pulleys, harnesses, windmills, sails, gears, smelters and wagons added up to enormous gains in energy efficiency. This allowed global exploration, warfare and construction – including pyramids and cathedrals – yet it did not prevent famine and widespread suffering. Much of the problem stemmed from animals, the “prime movers” themselves. People used as much as 75% of 18th- and 19th-century farmland to grow food for work animals. Most energy for heat, light, metallurgy and cooking came from burning biomass, such as wood, dung, plants and charcoal. This led to rampant deforestation. 

Modern mechanized farming started in Britain in the early 19th century and soon moved to the United States and elsewhere. It provided breakthroughs in crop yields by using manufactured fertilizers and machines powered by fossil fuels. These gains supported fast-growing populations and labor diversification. From the mid-19th century on, fossil fuels began to supplant biomass in about half the world, dramatically curtailing deforestation.

Sails and navigation techniques also improved enormously throughout the 18th and 19th centuries. On land, more and better roads and wagons led to better horse-powered transportation. Steam locomotives followed. By the turn of the 20th century, bicycles, streetcars and the first cars quickly overtook horses as prime movers. Steamships gradually supplanted sailing vessels.

“The steam engine was the first new prime mover successfully introduced since the adoption of windmills, which preceded it by more than 800 years.”

People began using coal widely in the mid-1900s, followed by charcoal, coke and steam. Fossil fuels originate from the sun and solar power, but they must be converted to another form for use. The widespread dominance of coal, then coke and steam, began in the mid-17th century, leading to the age of oil and gas after about 1900. The 19th century’s steam engines were the first major advance in energy technology in about eight centuries. Windmills and water wheels require specific locations, but workers could install steam engines anywhere. Their portability and effectiveness powered the Industrial Revolution. 

“The term industrial revolution’ is as appealing and deeply entrenched as it is misleading. The process of industrialization was a matter of gradual, often uneven, advances.”

At the outset of the 1900s, few countries produced much oil, then providing only 3% of the world’s fossil fuel energy. By 1950, that figure had risen to about 21%, and in 1972 crude oil comprised around 46% of all fossil fuels, exceeding that of coal.

With oil, electricity was the other prime mover of the 20th century and beyond. The harnessing of electricity across the decades took many contributing scientists starting as far back as the 17th century. But people didn’t put electricity to practical use as lighting until the 1880s. Thomas Edison, William Stanley and George Westinghouse created the foundations of the energy grid that now spans the 21st-century world.

Fossil fuels now supply about 85% of the world’s energy. Their use expanded the per capita energy consumption in wealthy nations by 300% to 600% over preindustrial times. The expansion revolutionized agriculture, propelled industrialization, spawned megacities, and gave rise to the IT and communications sectors – including newspapers, radio, computers and the internet.

Fossil fuels drove unprecedented economic growth and improvements in health, education and general standards of living. Starting in the late 1700s and accelerating through the 20th century, more efficient use of coal, steam, oil and gas propelled the West ahead of previously dominant China. Modernization and high energy consumption spread unevenly. In some parts of Asia and Africa, biomass fuels are still the prime movers.

Energy is an essential component of history.

The pursuit of more and better energy sources has enabled virtually every improvement to the human condition, but other factors also contributed. Wide disparities in the adoption and use of various primary fuels mean that history doesn’t have clearly demarcated lines to mark periods of dominant energy use in various nations throughout the centuries. 

Even in areas where energy modernization occurred early, the transition took a long time. Human and animal sources of energy coexisted with fossil fuels for centuries. The advent of modern energy can’t fully explain the major events of history – nor take credit as the main factor driving those events. Though it may partially explain the rise of great empires, energy offers almost no explanation for their collapse.

Without human ingenuity, most energy sources would be nearly useless.

Many crucial fuels would have had little historic impact without human ingenuity converting them for practical use. Wind did little for transportation and exploration until innovators improved navigational techniques and invented new instruments. Oil would have remained useful only for lamps if not for the internal combustion engine.

However, people did exercise innovation and invention, and energy does count as the most important nonhuman driver of economic, social and environmental activity throughout history. Each era’s access to and exploitation of its most efficient energy sources helps explain the power of a succession of empires from Rome to the United Kingdom – including the United States.

A nation’s mastery of the latest, best sources of energy largely explains its wealth.

Those who used energy well, such as the Japanese, prospered beyond those who used it poorly, such as the Soviet Union and, now, Russia. Japan imports virtually all its energy, while Russia remains one of the world’s largest exporters of energy. 

“More than in any other modern nation, the power and influence of the United States have been created by its extraordinarily high use of energy.”

But energy abundance in Russia and, even more so, in North America leads to great waste, including such irrational activities like urban driving in personal vehicles and spending great sums of money on oversized homes, cars, boats, useless entertainments and unfathomable amounts of junk. Though energy abuse has had a serious negative impact on the environment, turning back, unfortunately, doesn’t seem to be a realistic option.

Wealthy nations’ waste of fossil fuels harms them and the Earth, while poor nations cause great damage by stripping forests for energy.

Billions of people hope to emulate the way the West uses energy, though they would express that hope, instead, as a quest for a higher standard of living. Demand for energy will soar indefinitely. The unnecessary, unfortunate failure of nuclear power spawned new extraction techniques, such as fracking, which uses natural gas to drive massive electricity generators. The current abundance of relatively cheap energy and food in wealthy nations contributes to waste, obesity and compounding environmental degradation, most dangerously manifesting as global warming.

“New superior performances and efficiency gains do not mean that humanity has been using energy in a progressively more rational manner.”

Greedy energy use doesn’t correlate to national happiness or well-being. Above a modest allotment per person – a point North America and much of Western Europe have surpassed – higher per capita energy use doesn’t deliver significant advantages or a better life. The United States uses three times as much energy per capita as Italy and many more times than Cuba. Yet the United States suffers higher infant mortality, lower life expectancy and poorer educational results.

Having control of a nation’s energy tends to concentrate political power, enabling dictators such as Napoleon, Hitler, Mao, Saddam Hussein and the Saudi royals. Today, the quest for political power threatens humankind with thermonuclear bombs and other destructive weapons. The West abuses and wastes fossil fuels, but the problem isn’t just with the West. People elsewhere strip forests bare seeking biomass energy for cooking, lighting and heat.

Still, renewable energy sources are supplying a significant component of the world’s energy. Most renewable energy comes from water-powered hydroelectricity, which supplies some nations with most or all of the electricity they need.

Renewable energies, though promising, may offer too little, too late.

The Earth needs massive new and renewable energy sources to give its population a decent standard of living and to circumvent the drive to match Western use and abuse of fossil fuels. Energy wasters in rich nations should cut their consumption. It appears unlikely that renewable energies will replace fossil fuels in their capacity to meet soaring global energy demand – certainly not in time to avert worldwide environmental catastrophe. Without more effective and efficient means of harnessing renewable energies, the choice to curtail fossil-fuel use is a life-or-death decision for much of humankind.

About the Author

Vaclav Smil

Vaclav Smil’s other books include Should We Eat Meat; Global Catastrophes and Trends; Energy Myths and Realities; and Power Density.

Video & Podcast