# HUMAN SYSTEMS, THE ENVIRONMENT, AND SOCIETY

## Human Population

Nobody knows exactly what the total population of the world is. Not all countries take a regular census, or population count, of their people the way the United States and European countries do. But by 2000, scientists estimated that the world population had grown to more than 6 billion people. This huge population is distributed unevenly around the world. Over 3 billion people, or approximately 50% of the world’s population, live on one continent—Asia. And only two Asian countries—China and India—account for more than half of Asia’s 3 billion people.

Look over the figures in the table below. They show estimated populations for the year 2000. Which continent has the second largest population? Which has the smallest?

Global Population Estimates, 2000
 Continent Population (in millions of people) Asia 3,672 Europe 727 Africa 794 North America 314 South America 519 Australia 19 Antarctica (uninhabited) World Total (including islands) 6, 057

Estimates of population density give an even better idea of how unevenly populations are spread over Earth. Population density means the number of people that live in a given amount of space, usually a square mile or a square kilometer. Try to visualize the number of people that might live in a square-mile area of a city, where houses and apartments are crowded close together. Now compare that mental picture with the number of people living in a square-mile farming district. It is obvious that the city is a densely populated place; the farm area is sparsely populated. The table below outlines population densities on the world’s continents.

Global Population Densities, 2000
 Continent Average Number of People per Square Mile Asia 116 Europe 32 Africa 26 North America 15 South America 25 Australia 2

In land area, Asia is the world’s largest continent. Europe is second smallest. But according to the table, Europe’s population density is greater than other continents many times its size. In all countries, on all continents, people tend to live crowded together in cities and on fertile farmland. As a result, densities vary greatly within a country as well as among different countries. The tiny European country of the Netherlands, for example, is one of the most crowded countries in the world, with approximately 388 persons per square mile.

Every year the world’s population increases by some 40 million people. The table below shows how this rate of increase varies in different places around the globe.

Global Population Growth Rates, 1990–2000
 World Region(s) Annual Rate of Increase (percent) Africa 2.97 South America 1.82 Asia 1.71 Australia and the Pacific Islands 1.44 North America 0.81 Europe 0.47

The rate of population growth is low in the world’s wealthy countries—namely those in Europe plus the United States and Canada. It is highest among the poor countries of Africa and Latin America. Better medical care is cutting down on the number of deaths each year in African and Asian countries. At the same time the birth rate—the number of live births per 1,000 people each year—is higher in the poorer countries than in the wealthier ones.

## Population Settlement Patterns

If you looked at a population density map of the United States, you would notice that most of the western United States is sparsely populated. You would then think, “Of course. That is the area of the Rocky Mountains and deserts.” If so, you noticed an important factor in population settlement patterns: people tend to live in places with favorable physical features. Mountain areas are too cold and rugged for growing crops or transporting goods from one place to another. Deserts are too dry to support many crops and people.

If you were to look at a population density map of the world, you would see that people tend to crowd into the level lands of Earth. Here are most of the cities and farms. But you would also see large areas of level lands that are sparsely populated. The northern tundra has level land, but the climate is too cold to invite human activity. The Amazon Basin is too warm and densely forested; the Sahara, the deserts of the Arabian peninsula, and the highlands of China in central Asia are too dry and harsh to be favorable human environments. Climate and landforms both have a tremendous influence on where people choose to settle.

A world population map would also show that people and cities tend to cluster along seacoasts and rivers. These locations offer good transportation routes. Some rivers, such as the Nile in Egypt, also provide water for growing crops in dry climates. In parts of South America, most of the people live in the coastal highlands. These areas are cooler and more pleasant places to live than the warm lowlands inside the continent. Almost all of Australia’s people live in coastal areas to avoid the dry areas that cover most of the continent.

The trend to settle favorable physical environments has taken place over thousands of years of human history. Since the early 1900s, however, another trend has occurred. Before the 1900s, most of the world’s people made their living by farming. They lived in rural, or agricultural, regions. However, this pattern has reversed as manufacturing has increased and industry has grown. Now more and more people are moving to cities. In wealthy countries, more people live in urban areas, or areas in and around cities, than in rural areas. Poorer countries usually have more farmers than city dwellers, but their cities are steadily growing too. For instance, Mexico City, Mexico, and Săo Paulo, Brazil, each have well over 10 million people. People in both wealthy and poor countries are moving to cities to take jobs in factories, offices, stores, and the like. Unfortunately, there frequently are not enough jobs, especially in rapidly growing cities of poorer countries.

## Political and Cultural Divisions

The United States has 50 states. A map shows the boundaries of these states. These are called political boundaries, or ones that have been decided by people. People living within political boundaries share the same governments and many of the same economic and social concerns. Political boundaries separate the many nations of the world.

One hundred years ago, a political map of the world would have looked quite different from a map today. There were far fewer independent nations. Almost all of Africa plus many parts of Asia were colonies of European countries. As colonies, their governments and resources were controlled by other countries. Beginning in the 1940s, the colonial lands of Africa and Asia gained their independence. They are often referred to as new or developing nations, or ones that are building modern industries for the first time in their history. Although they became independent in the 1800s, Mexico, Central America, and most South American countries are also considered to be developing nations. Japan is a major exception in Asia. Japan was never ruled by a colonial power, and its wealth and industry match that of any other wealthy, or developed, nation.

People of the world also fall into large divisions that cross over national boundaries. These are the world’s cultural regions. People living in the same cultural region share common ways of life, languages, beliefs, and other cultural aspects. The United States and Canada, for example, make up one cultural region. Both were once English colonies; both have governments and laws based on English traditions; English is the major language spoken in both countries; and both countries are highly developed. The people of Latin America, on the other hand, speak mostly Spanish or Portuguese. Both languages are derived from the ancient Latin language, for which the region is named. Spain and Portugal controlled most of the colonies in Latin America between the 1500s and the 1800s. Other cultural regions include: the Middle East, Southeast Asia, the Pacific Islands, and Sub-Saharan Africa.

## Major Cultural Regions

### The United States and Canada

The United States and Canada cover most of the North American continent. Canada has more land than the United States; however, the United States has far more people—about 280 million. Canada has only about 31 million.

Almost every type of land and climate can be found in the United States and Canada: large forests, dry deserts and plateaus, rugged mountains, and fertile plains. Canada’s northern location makes much of the country cold the year round. Most of the United States has distinct seasonal changes. Its southern portions are much warmer than its northern portions.

Because both nations are former British colonies, most of their citizens speak English. The province of Quebec in eastern Canada once belonged to France. The people of Quebec speak mostly French. A province is a Canadian political division similar to a state of the United States.

The United States and Canada are two of the world’s largest food producers. But the United States has more usable farmland than Canada. Both Canada and the United States are highly developed industrial countries. The United States, in fact, is the world’s largest producer of manufactured goods. Canada and the United States trade, or exchange goods and services, with each other more than with any other countries. They cooperate in military defense. The boundary that separates the two countries is the longest unguarded border in the world.

### Latin America

Latin America takes in the whole area south of the United States, from the U.S.—Mexican border to the southern tip of South America. Latin America is often called a “land of contrasts.” Most countries of the region are Spanish-speaking. However, Portuguese is the language of Brazil, a huge country with about 122 million people. In the Caribbean, people of Haiti speak French, and people of former British colonies speak English.

The difference in landforms and climates is very striking in South America. Some of the world’s highest peaks top the Andes, a mountain range that runs along the western edge of the continent. High plateaus with cold, dry climates lie east of the Andes. Hot, humid forests of the Amazon River Basin cover much of Brazil, while Argentina has broad plains and a moderate climate.

Before Europeans discovered the Americas and the Spanish conquerors arrived, several Native American civilizations prospered in Latin America. The Aztecs built an empire in central Mexico, and the earlier Mayan civilization spread over eastern Mexico and Central America. The Incas controlled a large region in the Andes of South America. After the Spaniards and the Portuguese took over the region, many other Europeans settled there, especially during the nineteenth and twentieth centuries. If you visited some cities in the southern part of Chile, you would find that most people are blond and have blue eyes. This is because several generations of German settlers moved there.

European culture has had a lasting effect throughout Latin America. Yet the influence of Indian cultures is still strong, especially in Bolivia, Peru, Ecuador, Mexico, and Central America. African people were forced to come as slaves to Latin America many years ago; they and their descendants have had a strong impact on the cultures of Brazil and Caribbean countries. Latin American’s powerful neighbor, the United States, has also influenced its culture.

Economic development throughout the region is uneven. The three economic giants of Latin America are Brazil, Argentina, and Mexico; Haiti and Bolivia are extremely poor countries. To earn money, many countries sell large amounts of one or two resources to other countries—copper in the case of Chile and bananas in the case of many Central American countries. Brazil, on the other hand, produces cars, military weapons, and computers.

### Western Europe

Despite its small size, Western Europe has played a major role in shaping human history. The region remains a major economic, cultural, and political center. The region is less than half the size of the United States in land area, but its population is much greater than that of the United States.

Most of Western Europe lies on a large plain that stretches from the southern part of the United Kingdom to Russia. The Alps, Balkans, Pyrenees, and Apennines rise in the southern half and make up the region’s major mountains. But the most striking thing about Western Europe’s geography is its nearness to water; no place in the region is very far from the sea. All Western Europe is actually a large peninsula of peninsulas, or portions of land almost entirely surrounded by water.

Closeness to the sea is the greatest influence on the climate of Western Europe. Much of the region is located quite far north. Yet the climate is mild in most countries. Warm air over the North Atlantic Drift, a warm-water ocean current, accounts for the mild climate. This current originates in the subtropical warmth of the Gulf of Mexico, crosses the Atlantic Ocean, and reaches shores of the British Isles and other countries of Western Europe. The current does not reach as far north as the Scandinavian countries of Norway, Sweden, and Finland. Winters there are long and cold. Southern Europe, on the other hand, has hot summers and mild winters. Hot southern winds blow across the Mediterranean Sea to warm these lands.

Western Europe’s economy depends on trade. Its long coastline allows for easy shipment of goods over water routes. The region has also built an excellent system of railroads, highways, and canals for travel and transportation on land. Most of Western Europe is highly industrialized.

### Eastern Europe and the Former Soviet Union

If you travel from Western Europe into Eastern Europe, you will find broad areas of fertile land and some of the world’s largest wheat fields. The climates vary from bitterly cold in northern Siberia to mild along the Mediterranean coast of Albania.

After World War II, the Soviet Union established and dominated the communist governments of Eastern Europe. But between 1989 and 1991, the communist system collapsed, and the Iron Curtain that separated Eastern and Western Europe fell. East and West Germany were peacefully reunited. The communist dictator of Romania was overthrown and executed in 1989. Communist governments also were replaced in Bulgaria, Czechoslovakia, and Yugoslavia. A bloody civil war broke out in Yugoslavia in 1992 after the republics of Serbia, Croatia, and Slovenia broke away.

The biggest change occurred in the Union of Soviet Socialist Republics (U.S.S.R.), or the Soviet Union. Three Baltic republics—Estonia, Latvia, and Lithuania—declared independence from the U.S.S.R. in the fall of 1991. In December of 1991, the Soviet Union was disbanded. Ten of the twelve remaining republics formed a “Commonwealth of Independent States.” Russia is the largest and richest republic.

However, the former communist nations of Eastern Europe face many problems, such as inflation, political instability, and violence between ethnic groups.

### North Africa and the Middle East

The history of North Africa and the Middle East reaches far into the past. The region is often called the “cradle of civilization” because the earliest known farms and cities began there. Three of the world’s great religions—Judaism, Christianity, and Islam—originated in the Middle East. Islam, the religion based on the teachings of Mohammed, is now the religion of most of the region’s people.

The region is still intensely important today: it has almost two-thirds of the world’s oil resources; it is a crossroads for air and sea routes, including the one through the Suez Canal; it is an area of unrest that attracts the attention of powerful world nations. Wars and disputes among the Islamic nations and between them and the Jewish state of Israel make the region an area of continuing conflict.

Aside from the narrow strips along the Mediterranean Sea and the mountains in Iran and Turkey, most of the region is warm desert. The Sahara, in North Africa, is the world’s largest desert.

Oil provides enormous profits for nations along the Persian Gulf. In 1973, Arab oil producers stopped sending oil to the U.S. and the European nations that supported Israel in the Yom Kippur War. In 1991, Iraq invaded oil-rich Kuwait. The U.S. and other members of the United Nations formed a coalition against Iraq. In a brief war, known as “Desert Storm,” Iraq was driven out of Kuwait.

### Sub-Saharan Africa

Sub-Saharan Africa, as Africa south of the Sahara is often called, is a complex region. According to many scientists, it has more human history than any other part of the world. Over its long past, the people developed a wide variety of cultures and traditions. The region’s people still speak more than 800 different languages.

During the 1800s, the French, British, Belgians, and other Europeans established colonies in Africa. Europeans were building industries during these years. They used resources from their sub-Saharan colonies to help supply their industries. They also set up European-style governments and schools among the people of their African colonies.

Beginning in 1947, one African nation after another gained independence from European control. Today the new nations are working to build their own industries and to educate their people.

Sub-Saharan Africa’s physical geography is as unique as its human geography. Most of the land is a high plateau. Dense forests grow near the equator in western Africa. Savannas, however, cover by far the largest area. A savanna is a wide plain covered with grasses and a few scattered trees. For part of each year, rain falls on the savannas; the grasses grow thick and green. Then the dry season comes, and the savanna turns brown and empty.

Africans have been farmers and herders since the earliest times. Production is low, and many Africans produce only enough to feed their families. The new nations have made major efforts to improve food production. Irrigation and better farming techniques have increased the amount of corn and rice grown in a number of places. In other places, farmers are growing crops to sell for cash in other parts of the world. The chocolate or coconut you eat, the cola you drink, or the palm-oil soap you use may be manufactured from products of a farm in sub-Saharan Africa.

### South Asia, Southeast Asia, and East Asia

More than half of the world’s 6 billion people live in South, Southeast, and East Asia. Most are farmers living under the most crowded conditions on Earth. Crowding occurs because roughly half the land in the region is either too dry or too high, cold, and rugged for people to make a living. The Gobi Desert and the Himalayas, the huge mountain system that includes the highest mountain peak in the world, account for vast empty areas in the region. Lands nearer the Pacific and Indian oceans—where most of the people live—are generally warm, moist, and more suitable for farming than the inland areas.

Earthquakes, floods, and tropical storms are common, often destructive, natural forces. People of South and Southeast Asia plan their farming activities around the pattern of the more friendly monsoons. Monsoons are winds that blow from one direction for part of the year and from another direction for the other part. Summer monsoons bring rain and heat from the Indian Ocean to South and Southeast Asia. Winter monsoons bring cool, dry air from the inland mountains and highlands.

Crowding, difficult natural environments, and a late start in building industries have meant that most Asians are poor as measured by modern industrial standards. Yet Asian cultures are rich and varied and reach far into the past. Some of the world’s first civilizations grew up along the Indus River in India and the Hwang Ho in China. The Buddhist and Hindu religions developed in India before the Christian era in Western cultures.

Today the people of Asian countries still honor their rich traditions. At the same time they are rapidly building industries to compete with the United States and Europe and to improve their lives. Japan, the “Miracle of Asia,” led the way and is now a leading world industrial power. Other nations, including South Korea, Taiwan, and India, also have industrialized.

### The South Pacific and Australia

Thousands of tiny islands lie scattered across the Pacific south and west of Hawaii. Volcanoes and earthquakes raised some of the islands from the ocean floor. Other islands, called coral islands, are a buildup of skeletons from tiny sea animals. The people on the islands have had contacts with the modern world but live mostly in the ways of the past. The islanders often travel far from their islands to fish from sturdy canoes. They grow enough yams, rice, coconuts, bananas, and other foods to feed their families. They often have poor soils to work with, but the climate is warm and sunny the year round.

At the southern and western end of the island groups, spread over more than 4,000 miles, lie Australia and New Zealand. Australia and New Zealand are both modern countries. Most of their populations are descended from British settlers. A few of the original inhabitants still cling to their traditional ways, but most now follow modern ways as taught them by the British. Most people of the world know Australia and New Zealand for the fine wool produced from their many sheep ranches. Australia also grows a great deal of wheat to sell to other countries.

Australia is not only the world’s smallest continent, it is also the flattest and the driest one. About one-third of the continent is desert. Another third is dry grassland used mainly as grazing land. Most of the people live along the east coast. Lands there receive ample rainfall, and the climate is mild and pleasant. Australian cities cluster in this area. Western Australia is more sparsely populated.