More people are alive at this time than at any other point in Earth’s history, and most of the growth is concentrated in poor countries. Can Earth sustain nearly 8 billion people now, let alone the added billions in the future? Geographers have unique perspectives on the ability of people to live on Earth under a wide range of different and ever-changing conditions. India, shown in this image, will soon be the world’s most populous country, so its future population growth will have a major impact on the future population of the world as a whole.
Key Issue 1: Where Are People Distributed?
Population & Geography Geographers examine population problems by first identifying where people are found across the Earth. The location of Earth’s 8 billion people forms a regular distribution. Chapter 2 explains the spatial variation in population growth rates. With the rate of world population growth slowing in the twenty-first century, geographers have turned their attention to the global differences in access to health-care. 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.
The balance between resources and population distribution is a key thread woven throughout the chapter. Carrying capacity is the maximum population of a given 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. Overpopulation occurs when the number of people in an area surpasses the ability of the environment to support life at a decent standard of living.
The scientific study of population characteristics is demography. Geographers examine demographic data such as age, gender, occupation, and fertility to answer the “what’s there” question.
Population Portions
The world can be divided into seven portions each with a little more than 1 billion people each. These areas include the Western Hemisphere with Australia and New Zealand; sub-Saharan Africa; India and Sri Lanka; Europe, Russia, Turkey, and Northern Africa; Southwest and Central Asia; China; and East and Southeast Asia.
The world’s population is not distributed uniformly; two properties may be employed by Geographers to understand this distribution: concentration and density. These concepts can be displayed cartographically many ways, such as looking at concentration using a cartogram.
Population Concentrations Two-thirds of the Earth’s population is clustered in four regions. These four regions are characterized by low-lying terrain, with fertile soil and temperate climate. Concentrations of people are found near oceans (or rivers with easy access to an ocean) rather than in the interior of major landmasses.
Four Clusters The four aforementioned population clusters—East Asia, South Asia, Europe, and Southeast Asia—exhibit settlement in low-lying areas with fertile soil and temperate climates. Africa has several population clusters along its west coast (between Senegal and Nigeria) and along the east coast (between Eritrea and South Africa).
East Asia China is the most populous country in this cluster. China’s population is clustered near fertile river valleys and the Pacific Coast. The interior mountainous and desert regions of China are sparsely populated.
South Asia The major population cluster extends along a corridor from Lahore, Pakistan, through India and Bangladesh to the Bay of Bengal. The population is concentrated along the Indus and Ganges rivers, and also along the two coasts of India (the Arabian Sea to the west and the Bay of Bengal to the east).
Europe Four dozen countries constitute Europe, ranging from Monaco (with 2 square kilometers in land area) to Russia (the world’s largest country by land area, including its Asian part). The highest population concentrations are near the major rivers of Germany and Belgium and capital cities such as London and Paris.
Southeast Asia Indonesia, the world’s fourth-most populous country, is located in this cluster with highest population concentration of approximately 150 million people on the island of Java. Population clusters along river valleys and deltas on the Southeast Asian mainland.
Sparsely Populated Regions The sparsely populated regions include very dry areas, very wet areas, very cold areas, and mountains. These environments are not suitable for agricultural activities.
Dry Lands Twenty percent of Earth’s land surface is covered by areas too dry for farming. Sparsely populated deserts lack sufficient water supplies for crops, but some people raise animals adapted to the climate. Dry lands may contain natural resources such as petroleum reserves.
Wet Lands Located primarily near the equator few people live in lands with very high levels of precipitation and extreme heat. The heavy rains wash nutrients out of the soil and limit agricultural production.
Cold Lands Few humans live near the North and South poles, as much of the land is permanently frozen (permafrost) and unsuitable for agriculture. Few animals tolerate the extreme cold temperatures.
High Lands Many high elevation areas in the world are inhospitable to human settlement due to the mountains dominating these landscapes being steep and snow covered. Some plateau and mountain regions can support human settlement, especially those at low latitudes (near the equator) where agriculture is possible at high elevations.
Population Cartogram
A cartogram depicts the size of countries according to population. The population cartogram clearly shows the distinction between population and land area. India, China, and other countries of Asia dominate the map. Canada with a large land area is very small when represented by population alone.
Ecumene
The ecumene describes the areas occupied by permanent human habitation. Through time, the portion of the Earth used for human settlement has increased through time.
Population Density The number of people occupying a defined area of land, previously described in Chapter 1 as density, reveals the distribution of people compared to available resources. Three measures of density are widely used by geographers: arithmetic density, physiological density, and agricultural density.
Arithmetic Density In population geography, arithmetic density refers to the total number of people divided by the total land area (usually square kilometers or square miles). Arithmetic density enables geographers to compare the number of people per land unit in different regions of the world. However, arithmetic density does not pinpoint the population concentration within a given area.
Physiological Density Land suitable for agriculture is called arable land. In a region, the number of people supported by a unit area of arable land is called the physiological density. Physiological density can be considered a rough measure of a country’s food security. A large difference between the physiological density and arithmetic density indicates that most of a country’s land is unsuitable for intensive agriculture.
Agricultural Density The number of farmers per area of arable land is the agricultural density. Agricultural density is used by geographers as a measure of development. A country with many farmers and limited arable land would have a high agricultural density. Agricultural densities are lower in developed countries because technology and financial capital make it possible for a few people to farm extensive land areas and feed many people. Physiological and agricultural densities may be used in concert to help geographers understand relationships between population and resources in a country.
*indicates information specific to the text and is not in the AP Human Geography course
**indicates information is background or foundational to building further understanding and developmen
2.1 Key Terms
Cartogram A map in which the projection and scale are distorted in order to convey the information of a variable.
Agricultural density The ratio of the number of farmers to the amount of arable land
Arable land Land that can be farmed
Arithmetic density The total number of people divided by the total land area
Carrying capacity The maximum population size of the species that the environment can sustain
Demography The study of population
Ecumene The permanently inhabited portion of the earth as distinguished from the uninhabited or temporarily inhabited area
Overpopulation When there are not enough resources in an area to support a population
Physiological density The number of people per unit of area of arable land
Population distribution The pattern of where people live
Population pyramid A graph of the population of an area by age and sex - when a population is growing it takes a pyramid shape, hence the name
Push factor A force that motivates people to leave an area
Population Density The number of people occupying a defined area of land, previously described as density, the distribution of people compared to available resources. Three measure of density are widely used by geographers: arithmetic density, physological density and agricultural density
Urban Having to do with cities - urban areas are cities
Zero population growth (ZPG) When a country reaches replacement level fertility