Where Are People Distributed?

Geographers study population by first describing where Earth’s nearly 8 billion people are distributed. The chapter then turns to explaining why population is growing at different rates in different places. With the rate of world population growth slowing in the twenty-first century, geographers are increasingly concerned with differences in the health of people in different places and with the medical care available to them.

Population & Geography

The study of population geography is especially important for three reasons:

• More people are alive at this time than at any other point in Earth’s long history.

• Virtually all global population growth is concentrated in developing countries.

• The world’s population increased at a faster rate during the second half of the twentieth century than ever before in history; the rate has slowed in the twenty-first century but is still high by historical standards.

Geographers are interested in the relationship between population and Earth’s resources. Carrying capacity is the maximum population size of a species that the environment can sustain indefinitely, given the available resources such as food and water. The capacity of the land to sustain human life derives partly from characteristics of the natural environment and partly from human actions to modify the environment through agriculture, industry, and exploitation of raw materials. Overpopulation occurs when the number of people exceeds the capacity of the environment to support life at a decent standard of living.

From the perspective of globalization, some geographers argue that the world is already overburdened with too many people, or it will be in the near future. At the scale of local diversity, geographers find that overpopulation is a threat in some regions of the world but not in others. The capacity of Earth as a whole to support human life may be high, but some regions have a favorable balance between people and available resources, whereas others do not. Further, the regions with the most people are not the same as the regions with an unfavorable balance between population and resources.

The Challenge of Balancing People and Resources, Delhi, India

People living in parts of Delhi have no running water at home, so they obtain water by filling containers at a truck.

The scientific study of population characteristics is demography. Demographers look statistically at how people are distributed spatially by age, gender, occupation, fertility, health, and so on. Geographers are part of the team at organizations that do demographic studies, such as the Population Reference Bureau, the U.S. Bureau of the Census, and the United Nations Population Division. (See Doing Geography feature .)

Demographers can tell us with some precision the current population of the world and of particular places as well as population in the recent past. Forecasting the future population is much more challenging for demographers, but we need these estimates in order to plan for the future.

Pause & Reflect 2.1.1

What challenges for human populations arise from Earth’s carrying capacity?

Population Portions

The world can be divided into seven portions, each containing slightly more than 1 billion people. The combined population of North America, Latin America, the South Pacific, and Greenland (an area of 53 million square kilometers) is about the same as the population of India (3 million square kilometers) or eastern China (5 million square kilometers). The small size of the Asia portions shows the large number of the world’s inhabitants living there compared with the portion made up of North and South America, Australia, and New Zealand.

World Population Portions

Each of the seven portions indicated by color in this figure contains slightly more than 1 billion inhabitants.

Doing Geography

The Census

The single most important data source for population geography is the census (Figure 2-3). In the United States, a census of population and a census of housing take place once a decade, in years ending in zero, including 2010. Despite its importance, the census is controversial in many countries, for two reasons:

Nonparticipation. People who are homeless, ethnic minorities, and citizens of other countries who do not have proper immigration documents may be less likely to complete the census form. These individuals may fear that the census could turn over the forms to another government agency, such as the FBI or the Department of Homeland Security in the United States.

Sampling. Statistical sampling techniques can be utilized to get a more accurate count as well as to identify detailed characteristics of people, housing, and businesses. The U.S. Supreme Court has ruled that sampling may not be used to redraw Congressional district boundaries. Politicians sympathetic to the needs of people who are homeless and immigrants have been especially vocal in support of sampling, whereas those from small towns and rural areas, where the census count is more accurate, are more inclined to oppose it.

What’s Your POPULATION Geography?

1. Use your Internet browser to go to census.gov. What are the current populations of the United States and of the world?

2. Select Explore Data, then ExploreData Main, then American Fact Finder. Then go to QuickFacts and explore the data?