Ecological Imperialism: The Biological Expansion of Europe, 900-1900 is a book written by Alfred W. Crosby, an environmental historian, in 1986. The book expands on Crosby’s earlier work, The Columbian Exchange, which explored how plants, animals, and other living things were moved around the world during European colonization.

In Ecological Imperialism, Crosby explains why European settlers were able to create permanent communities in temperate areas worldwide. He argues that this success was largely due to the mix of disease-causing microbes, invasive plants, and domesticated animals that traveled with Europeans. These introduced species harmed local populations and changed natural environments. The book helped people understand the environmental effects of colonialism and changed how people think about the history of colonization by showing how nature played a key role. Crosby introduced the term “ecological imperialism” to describe how European plants, animals, and diseases contributed to the success of European colonists.

The book is a key work in the study of environmental history and has influenced other areas of research, such as postcolonial studies. It won the 1987 Ralph Waldo Emerson Award.

Contents

Crosby begins by noting that the populations of what he calls the "Neo-Europes" in temperate regions are mostly made up of people with European ancestry. He questions why so many Europeans settled in these distant lands and why these areas have been able to produce large amounts of food regularly. He also asks why many countries in these regions consistently rank among the world's top food exporters.

Although Europeans were generally hesitant to leave their homes until the early 1800s, the Neo-Europes saw a large wave of European settlers between 1820 and 1930. Crosby explains that this migration was driven by challenges in Europe, such as rapid population growth, limited farmland, conflicts between nations, persecution of minority groups, and advances in steam-powered transportation. He also asks why these regions were chosen as the main destinations for European expansion.

Crosby attributes the success of European imperialists to biogeographical factors. Europe and the Neo-Europes share similar latitudes, meaning they are mostly or partly located in temperate zones with similar climates. This is important because the plants and animals Europeans rely on for food typically need a climate with warm-to-cool temperatures and about 50 to 150 centimeters of rain each year. Just as farming spread from the Fertile Crescent to other regions, replacing hunter-gatherer lifestyles, it also spread successfully in the Neo-Europes.

Before this could happen, the native plants and animals in the Neo-Europes were different from those in Europe. When Europeans brought their own species to these regions, they had to compete with the local wildlife for survival. This competition led to the decline of many native species. Crosby notes that regions now known for exporting European crops and livestock, such as grains and meats, had no wheat, barley, rye, cattle, pigs, sheep, or goats 500 years ago.

Crosby argues that European success was not due to inherent superiority but to biological and ecological factors. One major factor was disease, which arises from human interaction with animals. As Europeans transitioned from hunter-gatherers to settled farmers and domesticated animals, they were exposed to diseases that later helped them conquer the Neo-Europes. Animals like mice, rats, roaches, houseflies, and worms in crowded settlements carried these diseases.

Living in close contact with domesticated animals and their germs, Europeans developed resistance to many diseases over time. Though millions died from epidemics like the Black Death in Europe, repeated outbreaks led to a population that gradually became more resistant to diseases such as measles and smallpox.

In contrast, many native populations in the Neo-Europes were still hunter-gatherers and had limited contact with animals. They were not exposed to the same diseases as Europeans. Crosby explains that when Europeans arrived, they brought diseases that were entirely new to these regions, giving them a major advantage. The consequences were severe, as indigenous populations faced devastating health impacts from these unfamiliar illnesses.

Legacy

Ecological Imperialism was based on Crosby's earlier work about the Columbian Exchange. Crosby said that Ecological Imperialism "took The Columbian Exchange up another notch in scope and abstraction." The book is part of a long tradition of academic work that helped change the way historians and others understand global historical and environmental changes. Ecological Imperialism, along with The Columbian Exchange, is considered an important book in the field of environmental history. The idea at the center of the book—the theory of ecological imperialism—has been called "one of the most lasting models for understanding past global environmental changes."

The book has also influenced other areas of study, such as postcolonial studies. Over the years, scholars have used and improved upon the book's ideas, applying them to regions outside the areas Crosby focused on. Ecological Imperialism has been cited as a major source of inspiration for popular books like Jared Diamond's 1997 Pulitzer Prize-winning work Guns, Germs, and Steel and journalist Charles C. Mann's books 1491 and 1493. Mann has said that Crosby encouraged him to write 1493 after Mann asked Crosby to update Ecological Imperialism.

Editions

The first edition of Ecological Imperialism was published by Cambridge University Press in 1986. A second edition was published by Cambridge in 2004, including a new preface by Crosby.

• Ecological Imperialism: The Biological Expansion of Europe, 900-1900, 1986, ISBN 0-521-32009-7 (hardback), ISBN 0-521-45690-8 (paperback)
• Ecological Imperialism: The Biological Expansion of Europe, 900-1900, second edition, 2004, ISBN 0-521-83732-4 (hardback), ISBN 0-521-54618-4 (paperback)