City and Environment

2. Population, Urbanization, and Environment

2 Population, Urbanization, and Environment POPULATION GROWTH IT IS DIFFICULT to discuss population without referring to three interrelated dimensions: magnitude, space, and time. Anyone engaged in population policy matters knows that one cannot make a convincing argument about population growth without some reference to the spatial and temporal specificity of growth, which highlights the differential nature of population impacts from one place to another. Beyond this methodological specificity, however, population discussions must also focus on the sociopolitical, cultural, historical, and economic contexts within which specific demographic patterns occur. From John Graunt’s “life table” (1662)1 of London to the most recent publications of the United Nations, demographic publications have touched upon the complexity of population through this multidimensional approach. Discussions of population “catastrophes” must likewise take into account time, space, politics, economy, and culture. One need only read Malthus’s nineteenth-century treatise on population to appreciate the degree to which the sociopolitical and cultural values of a community determine its perception of population issues and of how they can best be managed . The looming population problems that confront us at various geographic scales are complex, and finding solutions is no easy task. Given that our focus here is on cities, population issues will be examined within this context. Not only have cities acted throughout history as geographic nodes around which people have gathered in large numbers , but in the last few centuries they have also gradually become the major areas of human occupation. Urbanization rates in a number of countries exceeded 50 percent in the twentieth century, suggesting that people have looked to cities as places of work and leisure at a faster pace than ever before in human history. Cities have thus become arenas in which the dynamics of population are played out. 1For a discussion of Graunt’s importance to demographic studies, see Szreter (2001). POPULATION AND URBAN HISTORY Historically speaking, the largest concentrations of human population have occurred in cities, and it is in the course of managing these higher population densities—from resource delivery to management—that city-states and what we call civilization have arisen. Among the earliest cities, the Sumerian city of Uruk had a population density of 100–150 persons per hectare as early as 3300 B.C. (see Table 2.1). This is similar to the population density of Paris in the early nineteenth century. For a city of such magnitude, a functioning infrastructure was a necessity. It is in understanding the demography of cities, in ancient and modern times alike, that we can begin to discuss how such places function and how their affairs are planned and implemented. Uruk may inspire images of Gilgamesh, but its twenty to thirty thousand inhabitants needed water, food, markets, garbage collection and clean up, and many other daily goods and services that are usually absent from our images of the past. An important aspect of early cities was the physical limitation imposed upon them by the construction of walls. Growth beyond a certain level was unmanageable and therefore prohibited. The practice of prohibiting large numbers of visitors and merchants from staying for long periods of time in a city was common even in medieval Europe. As Table 2.1 illustrates, a city’s population growth was closely tied to its size, as determined by the location of its walls. In the case of Uruk, that meant a proportional growth of three hundred hectares and twenty Population, Urbanization, and Environment 39 TABLE 2.1. Estimated Population of Various Historical Cities Size Decade City Name (in hectares) Estimated Population 3300 B.C. Uruk 200 20,000–30,000 2800 B.C. Uruk 550 40,000–82,500 2100 B.C. Rakhigarhi 80 8,000–12,000 Harappa 150 15,000–22,500 Mohenjo-Daro 250 20,000–37,500 Ganweriwala 80 8,000–12,000 Dholavira 100 10,000–15,000 1600 B.C. Avaris 1000 100,000–150,000 1200 B.C. Tyre 70 7,000–30,000 1360 B.C. Chengchow 320 32,000–48,000 1360 B.C. Erech 450 45,000–67,500 Source: Pasciuti and Chase-Dunn (2002). to thirty thousand persons between 3200 and 2800 B.C. It was only after the demise of walls as a safety feature—due partially to the invention of gunpowder—that massive urban growth became physically possible. The implicit connection between demography, physical structure, and urban services, including...