The global context for this epochal economic transformation lies in a very substantial increase in human numbers from about 375 million people in 1400 to about 1 billion in the early nineteenth century. Accompanying this growth in population was an emerging energy crisis, most pronounced in Western Europe, China, and Japan, as wood and charcoal, the major industrial fuels, became scarcer and their prices rose. In short, “global energy demands began to push against the existing local and regional ecological limits.”2 In broad terms, the Industrial Revolution marks a human response to that dilemma as nonrenewable fossil fuels such as coal, oil, and natural gas replaced the earlier reliance on the endlessly renewable energy sources of wind, water, wood, and the muscle power of people and animals. It was a breakthrough of unprecedented proportions that made available for human use, at least temporarily, immensely greater quantities of energy.

It also wrought, of course, a mounting impact on the environment. The massive extraction of nonrenewable raw materials to feed and to fuel industrial machinery—coal, iron ore, petroleum, and much more—altered the landscape in many places. Sewers and industrial waste emptied into rivers, turning them into poisonous cesspools. In 1858, the Thames River running through London smelled so bad that the British House of Commons had to suspend its session. Smoke from coal-fired industries and domestic use polluted the air in urban areas and sharply increased the incidence of respiratory illness. (See the chapter-opening image.) Against these conditions a number of individuals and small groups raised their voices. Romantic poets such as William Blake and William Wordsworth inveighed against the “dark satanic mills” of industrial England and nostalgically urged a return to the “green and pleasant land” of an earlier time. Here were early and local signs of what became by the late twentieth century an issue of unprecedented and global proportions. For many historians, the Industrial Revolution marked a new era in both human history and the history of the planet that scientists increasingly call the Anthropocene, or the “age of man.” Increasingly, human industrial activity left a mark not only on human society but also on the ecological, atmospheric, and geological history of the earth.

More immediately and more obviously, however, access to huge new sources of energy gave rise to an enormously increased output of goods and services. In Britain, where the Industrial Revolution began, industrial output increased some fiftyfold between 1750 and 1900. It was a wholly unprecedented and previously unimaginable jump in the capacity of human societies to produce wealth. Lying behind it was a great acceleration in the rate of technological innovation, not simply this or that invention—the spinning jenny, power loom, steam engine, or cotton gin—but a “culture of innovation,” a widespread and almost obsessive belief that things could be endlessly improved.

Early signs of the technological creativity that spawned the Industrial Revolution appeared in eighteenth-century Britain, where a variety of innovations transformed cotton textile production. It was only in the nineteenth century, though, that Europeans in general and the British in particular more clearly forged ahead of the rest of the world. The great breakthrough was the coal-fired steam engine, which provided an inanimate and almost limitless source of power beyond that of wind, water, or muscle and could be used to drive any number of machines as well as locomotives and oceangoing ships. Soon the Industrial Revolution spread beyond the textile industry to iron and steel production, railroads and steamships, food processing, and construction. Later in the nineteenth century, a so-called second Industrial Revolution focused on chemicals, electricity, precision machinery, the telegraph and telephone, rubber, printing, and much more. Agriculture too was affected as mechanical reapers, chemical fertilizers, pesticides, and refrigeration transformed this most ancient of industries. Technical innovation occurred in more modest ways as well. Patents for horseshoes in the United States, for example, grew from fewer than five per year before 1840 to thirty to forty per year by the end of the century. Furthermore, industrialization soon spread beyond Britain to continental Western Europe and then, in the second half of the century, to the United States, Russia, and Japan.

In the twentieth century, the Industrial Revolution became global as a number of Asian, African, and Latin American countries developed substantial industrial sectors. Oil, natural gas, and nuclear reactions joined coal as widely available sources of energy, and new industries emerged in automobiles, airplanes, consumer durable goods, electronics, computers, and on and on. It was a cumulative process that, despite periodic ups and downs, accelerated over time. More than anything else, this continuous emergence of new techniques of production, together with the massive economic growth they made possible and the environmental impact they generated, mark the past 250 years as a distinct phase of human history.