Energy in Prehistory

This chapter discusses the use of energy during prehistoric times. Our direct ancestors spent their lives as simple foragers, and it was only about 10,000 years ago that the first small populations of our species began a sedentary existence based on the domestication of plants and animals. This means that for millions of years, the foraging strategies of hominins resembled those of their primate ancestors, but we now have isotopic evidence from East Africa that by about 3.5 million years ago hominin diets began to diverge from those of extant apes. The chapter first considers how bipedalism started a cascade of enormous evolutionary adjustments such as adaptations underlying tool use and adaptation to high-quality, energy-dense foods (meat, nuts) before providing an overview of foraging societies and the origins of agriculture.

Energy in World History

This chapter discusses the place of energy in world history. It examines historical milestones—such as the rise of larger populations organized with greater social complexity into nation-states and supranational collectives, and enjoying a higher quality of life—in terms of dominant energy sources and leading prime movers, as well as the most important socioeconomic consequences of these technical changes. It also considers grand patterns in the consumption of energy throughout history, focusing on the long-term relationship between human accomplishments and dominant energy sources and changing prime movers in terms of energy eras and transitions. Finally, it outlines trends that have accompanied the growth of unit power of inanimate prime movers and the accumulation of their total capacity; transformations of the fossil-fuel era including new structures of social relations; imperatives of energy needs and uses; and the importance of harnessing energies and controlling their conversion to supply.

Preindustrial Prime Movers and Fuels

This chapter discusses the prime movers and fuels that drove advances in manufacturing techniques, including those in metallurgy, in preindustrial societies. Some of the conversions involving prime movers and fuels helped energize the initial stages of modern industrialization. Two principal roads led to higher outputs and better efficiencies: multiplication of small forces, especially with the application of animate energy, and technical innovation, which introduced new energy conversions or increased the efficiencies of established processes. The chapter first considers the kinds, capacities, and limits of all traditional prime movers—human and animal muscles, wind, and water—as well as the combustion of phytomass fuels, mostly wood and charcoal made from it, before analyzing the uses of prime movers and fuels in critical segments of traditional economies: food preparation, provision of heat and light, land and waterborne transportation, construction, and color and ferrous metallurgy.

Fossil Fuels, Primary Electricity, and Renewables

This chapter discusses the evolution in uses of fossil fuels, primary electricity, and renewable energy. It first considers the transition from phytomass fuels to fossil fuels and how it resulted in the substantial increase in per capita consumption of energy. It then explores the beginnings and diffusion of coal extraction, the replacement of charcoal by metallurgical coke, and the introduction of steam engines and oil and internal combustion engines. It also looks at technical innovations brought by the transition from phytomass fuels to fossil fuels and from animate to mechanical prime movers, focusing on trends in the production of coal, hydrocarbons, and electricity as well as renewable energy and the use of prime movers in transportation.

Fossil-Fueled Civilization

This chapter discusses the rise of a fossil fuel-driven civilization. Modern civilization depends on extracting immense energy stores, depleting finite fossil fuel deposits that cannot be replenished even on time scales of a magnitude longer than the existence of the human species. By turning to these rich stores we have created societies that transform unprecedented amounts of energy, resulting in enormous improvements in agricultural productivity and crop yields. This chapter considers how unprecedented power has sparked a tremendous increase in consumption of energy, particularly fossil fuels and electricity, in areas such as modern agriculture, transportation, and information and communication. It also examines the contribution of energy to industrialization and economic growth and concludes with an assessment of the negative consequences of high energy use by modern societies.

Traditional Farming

This chapter discusses the use of energy in traditional farming. The evolution of agriculture appears to be a continuing effort to increase land productivity (to increase digestible energy yield) in order to accommodate larger populations. Owing to the overwhelmingly vegetarian diets of all traditional peasant societies, it is important to focus on the output of digestible energy produced in staple crops in general and grains in particular. The chapter first provides an overview of the link between food energy and the evolution of peasant societies before considering the commonalities and peculiarities of tools and machines used in agronomic practices. It then examines the dominance of grains in traditional agriculture, with particular emphasis on their energy density and nutritional content. It also analyzes routes to gradual intensification of agriculture, along with the persistence and innovation in traditional farming practices. Finally, it assesses the limits and achievements of traditional agriculture.

Energy and Society

This chapter shows how energy has shaped society, from prehistoric times through today’s fossil fuel-driven civilization. It suggests that both prehistoric human evolution and the course of history can be interpreted as the quest for controlling greater stores and flows of more concentrated and more versatile forms of energy. It also views human dependence on ever-higher energy flows as an inevitable continuation of organismic evolution. The chapter first provides an overview of how energy flows and storages are measured before discussing how the combustion of fossil fuels and the generation of electricity gave rise to a new form of high-energy civilization whose primary energy sources now include renewable energy such as solar and wind energy. It then considers several first principles that underlie all conversions of energy, including those for calculating energy and power, and concludes with an assessment of complexities and caveats involved in measuring energy storages and flows.