Figure 1. Deevey’s graph of the rise of global population first appeared in a 1960 article in Scientific American. According to his analysis, human numbers rose notably at three times in the past, corresponding to the advent of toolmaking, of agriculture and of industry, but this appearance is an artifact of the graph.
The extent to which human beings affect the environment depends, in large measure, on the number of people in the world. Despite the paramount significance of this statistic, many students, environmental analysts and even policymakers have a distorted understanding of the history of population growth. The confusion stems from a single misleading graph that often appears in the environmental literature.
The graph in question gives the distinct impression that human numbers skyrocketed during three relatively discrete periods—specifically, at the advent of toolmaking, agriculture and industrialization—but in each case subsequently stabilized. Edward S. Deevey, Jr., a noted ecologist and member of the National Academy of Sciences, first presented the problematic plot in 1960, in an article about human population in Scientific American (one of the eight he published in that magazine before his death in 1988). He wrote, “the population curve has moved upward stepwise in response to the three major revolutions that have marked the evolution of culture . . . But the evolution of the population size also indicates the approach to equilibrium in the two interrevolutionary periods of the past.”
Since Deevey penned this description, various renditions of his figure have appeared in at least seven other books or articles on the subject—most of which were published since 1990. What rekindled interest in a 41-year-old graph? The answer is plain: In recent years, many scholars have sought to better understand the links between technology and population growth. And some of them uncritically accepted Deevey’s view that two rapid increases in population were followed byperiods of approximate stasis.