WHAT IS THE CURRENT WORLD'S POPULATION?

WHAT IS POPULATION DISTRIBUTION?

The world’s population, or total number of people, is spread unevenly over the Earth’s surface. Some places have large numbers of people. In other places, the population is very small. Population distribution describes the way the population is spread out over the Earth.

The reasons population is distributed as it is may seem unclear. Scientists called demographers try to figure it out. Demographers study the populations of the world. They examine such things as rates of birth, marriage, and death. And they look at the reasons why people choose to live in certain areas.

WHY IS POPULATION DISTRIBUTION UNEVEN?

To answer this question, demographers start with the idea that people are choosy. Recall an important fact about the Earth’s surface. Many of the Earth’s landforms are rugged mountains, hot deserts, and dry land with little vegetation. Few people can live in these places.

Many factors make a location a good place for people to live. Most major civilizations of world history began along bodies of water. Rivers and lakes form natural “roads” for trade and travel. Also, rivers and lakes supply fresh water for drinking and farming. People also prefer areas of flat, fertile soil. There they can grow food and build easily. Therefore, plains and valleys are easy to settle. Flat coastal areas make it easy for people to trade by ship with other countries.

Other factors affect where people live. People prefer areas where the climate is not too hot or too cold. And where there is adequate rainfall. These places make it easier to raise food crops and animals. People also prefer places with natural resources to build houses and make products. For instance, few trees grew on the American Great Plains. Few people settled there at first. They went on to other regions.

CONTINENTS POPULOUS AND NOT POPULOUS

These reasons explain why more than 1 percent of the Earth’s people –about 4.9 billion- live in Asia, Europe, and North America. These continents total only about 53 percent of the world’s land. However, they have fertile soil, plains, valleys, and other favorable landforms. They also have fresh water, rich natural resources, and good climates.

Other continents have smaller populations partly because it is harder to live there. For example, Australia is about three million square miles, about as large as the continental United States. Only about 19 million people live in Australia, however. About the same number of people live in just the state of New York. Australia’s environment is mostly desert or dry grassland. There are few rivers and little rainfall. As a result, most people live along the coasts, where conditions are better.

In Africa, too, landforms and climates limit population. Africa has about 20 percent of the world’s land. But it has only about 13 percent of the world’s population. Africa has two of the world’s largest deserts, one in the north and one in the south. Then there are broad bands of land that get little rain. In the center of the continent, along the Equator, there is a vast rain forest. Therefore, many people in Africa live along its narrow costs.

Landforms and climates also limit South America’s population. About 340 million people live there. Most live along the continent’s Atlantic coast. Other regions have soaring mountains, vast dry plains, and thick rain forests. Fewer people live in these areas.

WHAT IS POPULATION DENSITY?

How many people live on your street or in your neighborhood? The average number of people who live in a square mile (or square kilometer) is called population density. In every city and country, population density varies from one area to another. In a country with a high density, people are crowded together. Japan has one of the highest population densities in the world. Almost all of its 126 million people live on only 16 percent of the land. In Tokyo alone, there are more than 25,000 people per square mile (9,664 people per sq km).

In contrast, Canada has a low population density. It is almost 9 persons per square mile (three persons per sq km). Canada is bigger than the United States. But only about 31 million live there. Many factors affect Canada’s population. For instance, its cool climate has a short growing season. This limits farming.

STUDYING POPULATION DENSITY

How do demographers measure population density? They divide the number of people living in a place by the number of square miles (o sq km) of that place. For example, California’s population is 33,871,648people. Its land area is 155,973 square miles (403,970sq km). Therefore, California’s average population density is 217,2 persons per square mile (83.8 persons per sq km)

Remember that population density is an average.

SOURCE: Geography Tools and concepts, World Explorer. Pearson Education. Pages 55-59