CHAPTER 4
Geography and the World
Ecosystems
Over millions of years, physical processes have shaped and reshaped Earth’s surface. The continents we know today did not always exist in their current form. Over time, landmasses break away from one another or collide with one another, forming new landmasses. Forces inside Earth cause mountain ranges to rise up, but over time, wind and water wear the rocks away. As a result, Earth has a highly varied landscape. Different locations have different landforms and different climates, and they are inhabited by different groups of plants and animals.
The climate of a region encompasses many things: the prevailing winds, temperatures, and the amount and type of precipitation, averaged over time. Climate is affected by geographical factors such as the proximity of mountains or large bodies of fresh or saltwater. Climate can change when any of these factors changes.
The term ecosystem refers to the ongoing interaction between the land, the climate, and living organisms in a particular location. All the factors work together in a certain way to create a natural system that sustains the organisms that live there. For example, in a forest in a temperate region of North America, trees produce nuts and fruits as part of their reproductive cycle. Small animals and birds survive by eating the nuts and fruits. Wolves and hawks survive by preying on the smaller animals and birds. Other animals survive by eating the insects that live in the soil and on the trees. The remains of dead plants and animals supply nutrients to the soil that nourish plants and trees. The whole system works together to sustain one generation of living things after another.
Earth is divided into many different ecosystems. For example, the tropical ecosystem of the South American rain forests is completely different in terms of climate, precipitation, and living organisms from the desert ecosystem in the southwestern United States. Much of the United States and Western Europe is located in an area of moderate climate called the temperate zone.
EXERCISE 1
Ecosystems
Directions: Choose the best answer to each of the following questions.
1. Which of the following is NOT a global ecosystem?
A. Temperate
B. Desert
C. Tropical
D. Deciduous
Question 2 is based on the following passage.
Storms from the Pacific Ocean usually drop their moisture when they reach the western slopes of the mountains in California, Oregon, and Washington. The area east of the mountains, where little rain falls, is said to be in a rain shadow.
2. What kind of ecosystem would you expect to find in a rain shadow?
A. Temperate
B. Desert
C. Tropical
D. Arctic
Answers are on page 828.
Geography and the Development of Human Societies
Geography largely determines how and where people live. The climate and the physical features, or topography, of the land are very important. Areas with very cold climates, like northern Canada, are sparsely populated. Areas with very dry climates also generally have few inhabitants. Mountainous areas with harsh climates are usually less populated than plains, where farming is easier. Throughout history, people have tended to settle in places where the soil is fertile, where freshwater is abundant, and where travel is relatively easy. That is why, for example, river valleys in the temperate zones, such as the Nile valley in Egypt or the Yangtze valley in China, were the sites of the earliest civilizations. Today population tends to be greatest in coastal areas, often near harbors where shipping makes it easy to transport people and goods. These areas attract people because they provide comparatively more economic opportunities.
Geography and climate affect the choices people make. The climate determines the clothing people wear, the crops they grow, the animals they raise for food, and the kinds of transportation they use. For example, the Italian peninsula is mountainous, with dry, rocky soil. Together with the mild temperatures of the Mediterranean region, this makes the perfect environment for growing grapes. These geographical factors have made Italy a major producer and exporter of wine since the days of ancient Rome.
Geography also affects conflicts between human societies. Countries must always consider how easily they can defend their borders. Countries with natural border defenses such as wide oceans or high mountain ranges are easier to defend than countries located in the middle of broad plains and surrounded by hostile neighbors.
Geographical factors can also dictate success or failure in war. Distance is one important factor—this was especially true before the invention of airplanes. The farther an army marches from its sources of supply, the greater the risk of defeat. Invading armies can also encounter harsh, unfamiliar weather conditions or mountainous terrain that makes transportation difficult. Geography has been a major factor in wars throughout human history.
EXERCISE 2
Geography and the Development of Human Societies
Directions: Choose the best answer to each of the following questions.
1. Which of the following is NOT a reason why many cities are built beside rivers?
A. The surrounding area is fertile and suitable for agriculture.
B. Freshwater for people and livestock is readily available.
C. Ports make travel and trade quick and convenient.
D. River banks are easy to defend against invaders.
2. ________________ are natural borders that countries have used as defenses against invaders and conquerors.
A. Broad plains
B. Wide river valleys
C. High mountains
D. Dry, rocky soils
Answers are on page 828.
Human Changes to the Environment
Human beings have significantly altered every natural environment in which they have settled.
They turn over the soil and sow crops. They may fell whole forests in order to clear land for farming or building. They create systems for irrigation and waste disposal. They build walls and fences to mark property borders. Large human civilizations go beyond these steps. They build bridges, roads, and cities. Since the beginning of the industrial age, people have been building factories, mines, and railroads. All these human activities alter an environment.
Large human societies need to manage resources. A natural resource is something of value that is supplied by the environment that is needed by or useful to living beings. This includes water, forests, minerals, air, animals, fossil fuels, plants, and rocks. Since the start of the Industrial Revolution in the early 19th century, people have been consuming natural resources at an ever-increasing rate. Some natural resources, such as coal, oil, and natural gas, are limited or finite. With continual use, they will one day run out. Sustainability refers to a way of using natural resources without depleting or destroying them.
Industrialization has produced pollution of air, land, and water on a massive scale. The problem has only grown worse over time; as the 21st century begins, it has resulted in global warming. Average temperatures have risen all over Earth, melting glaciers and causing sea levels to rise. Societies have responded to environmental problems in a variety of ways, creating a “green movement.” People recycle used products in order to reduce the amount of waste. They plant gardens in cities, on vacant land, and on rooftops. Farmers have changed their farming methods to make better use of the soil. Some farmers forgo the use of manufactured pesticides to raise organic crops. However, not all nations participate in these protective measures; some fear damage to their economies if they have to convert factories to cleaner, more environmentally responsible methods of production and waste disposal.
EXERCISE 3
Human Changes to the Environment
Directions: Choose the best answer to the following question.
Question 1 is based on the following graph.
1. According to the graph, in which decade did total water use begin to exceed 3000 km3 per year?
A. 1970s
B. 1980s
C. 1990s
D. 2000s
2. According to the graph, the amount of water used for agriculture increased from 1500 km3 per year in 1960 to ________________ in 2000.
A. 2000 km3 per year
B. 2500 km3 per year
C. 3000 km3 per year
D. 3500 km3 per year
Answers are on page 828.
Human Migration
Migration is the movement of large numbers of people from one country, place, or region to another. Human migrations have occurred throughout history prompted by population trends and issues. There is a connection between human migration and geography and environment. In many cases, people migrate to regions where farmland is available or where crops can be grown more successfully. People also migrate in order to find a better climate, to obtain jobs or natural resources, or to avoid poverty, wars, or the effects of a natural disaster.
To immigrate means to move into a country, usually to establish permanent residence. To emigrate, on the other hand, means to leave in order to settle in another place. People may immigrate or emigrate for a variety of reasons. At times, groups of people have been dispersed outside of their homelands either by choice or involuntarily. This scattering of groups of people is called a diaspora.
When people move to new lands, they experience new culture. Culture refers to the way of life of a particular group of people. This includes their arts, music, literature, language, values, religion, shared beliefs, clothing, and food. Cultural diffusion describes the spread of cultural ideas to new groups of people. This can take place when people with different cultures live in close proximity to one another. Over time, contact between the cultures leads to a mix. Cultural diffusion can also occur when one country conquers another and the defeated people are forced to accept the culture of the victors. Today, technology such as the media and the Internet plays a part in the widespread sharing of cultural ideas and beliefs. When people from different ethnic backgrounds integrate into the main culture of a society, they are said to assimilate. People in this situation do not necessarily abandon their traditional culture, but they accept many of the cultural ideas and practices of the dominant main culture.
EXERCISE 4
Human Migration
Directions: Choose the best answer to each of the following questions.
1. Tex-Mex, a combination of traditional Mexican cuisine and foods popular with American settlers in Texas, is an example of ________________.
A. assimilation
B. migration
C. cultural diffusion
D. sustainability
2. Read the passage, and then answer the question.
The great famine of 1845–1852 in Ireland was a catastrophe for the Irish. As many as 80 percent of Irish people left home and settled in countries as far away as the United States, Canada, Argentina, Australia, and New Zealand. This mass emigration was one of history’s great diasporas.
Which of the following would NOT be termed a diaspora?
A. the expulsion of Jewish people from Europe prior to and during World War II
B. the enslavement of West African people and their forcible transportation to the New World
C. the migration of Chinese people throughout Southeast Asia in search of better economic opportunities
D. the conquest of Native American peoples in South America by the Spanish
Answers are on page 828.
Population Trends and Issues
In early history, nearly all people lived in rural societies centered on agriculture. By contrast, much of today’s world is an urban society in which most people live in towns and cities. Today more than 50 percent of the world’s population lives in urban areas. This is the first time in history that this has been true. The growth of urban populations is expected to continue. There are numerous reasons for this trend. Cities offer many more opportunities for employment, education, and health care than rural areas with lower populations.
However, moving from a rural area to an urban area does not guarantee a higher quality of life. Particularly in developing countries in Asia, Africa, or Latin America, many people who move to cities with little or no resources of their own soon find themselves living in poverty. In those countries, the cities do not provide enough economic opportunities to support the rapidly increasing population. Poverty levels are usually highest in areas where population growth is fastest.
In 2013 the estimated total world population was 7.2 billion. This is expected to increase to 10.9 billion by the beginning of the next century. Most of this population growth is expected to occur in developing countries. In the more developed countries—the European and North American countries and Japan—population growth is much slower, mainly because family size is typically significantly smaller.
EXERCISE 5
Population Trends and Issues
Directions: Choose the best answer to the following questions.
Questions 1 and 2 are based on the following graph.
1. Based on the graph, which inference can be made?
A. Experts can predict the world’s exact population in the year 2100.
B. Experts agree that the world’s population will decrease by 2100.
C. The world’s population is expected to continue to increase over the next 75 years.
D. The world’s population is expected to triple in the second half of the 21st century.
2. True or False? By 2070, the world’s population is expected to be three times as great as it was in 1970.
Answers are on page 828.
Geography Tools and Skills
We use the term place or region to refer to a location on Earth. A place is an individual location—a single country, town, or city. A region is a group of locations—the collective identity of several adjoining countries, states, or provinces.
Various tools are used to show the spatial organization of people, places, and environments on Earth’s surface. A globe is the most accurate representation because it is the same spherical shape as Earth. However, even the largest globe is scaled down so far in size from the actual Earth that it cannot show much detail. Flat maps distort the actual curvature of the land, but a close-up map of a small area can show much more detail than a globe.
Different types of maps can show many physical and human characteristics of places and regions. Take, for instance, an ordinary map of the United States. It shows how Americans decided to divide their country into specific states for political purposes. You might take the same map and shade it to show the different regions: Northeast, Midwest, Southeast, Southwest, and Northwest. You might shade the map in different colors to show where different major crops are grown—such as wheat, corn, potatoes, and oranges. You might shade the map to show average temperature, rainfall, or elevation above sea level.
Maps come in many varieties. A political map shows the names and borders of countries, provinces or states, cities, and towns. A topographical map shows comparative elevation above sea level. A climate map can show which areas receive the most and least annual rainfall and which have the coldest and hottest temperatures.
You can locate any place on Earth by plotting its latitude and longitude. When you look at a globe, you will see a crisscross grid of latitude and longitude lines. A location’s latitude gives its distance north or south of the equator. A location’s longitude is an angular measure giving its distance east or west of the prime meridian, a north-south line running through a location near London in Great Britain. Latitude and longitude are measured in degrees (°) and minutes ('). The equator is considered to be 0° latitude. The north and south pole are located at 90° north and 90° south latitude, respectively. The prime meridian is considered to be 0° longitude.
EXERCISE 6
Geography Tools and Skills
Directions: Choose the best answer to each of the following questions.
1. If you want to plan a route for a hiking trip in a mountainous area, which kind of map would you be likely to consult?
A. climate
B. political
C. highway
D. topographical
2. The equator crosses which continents?
A. South America, Africa, and Asia
B. North America, Europe, and Asia
C. South America, Europe, and Australia
D. North America, Africa, and Asia
Answers are on page 828.
PRACTICE
Geography and the World
Directions: Choose the best answer to each of the following questions.
1. Which statement is true regarding how geography affects the development of societies?
A. Groups of people often establish their first settlements in mountainous regions.
B. People usually locate their settlements away from large bodies of water.
C. The availability of natural resources influences where people settle.
D. Societies develop in areas where health care is easily available.
Question 2 is based on the following graph.
2. Which of the following can be inferred from this graph?
A. Greenhouse gases in the atmosphere have increased rapidly since the start of industrialization in the 18th century.
B. Greenhouse gases in the atmosphere have decreased as world population has increased.
C. There was less carbon dioxide than methane in the atmosphere before Europeans colonized the New World.
D. There was more carbon dioxide in the atmosphere before the European colonization of the New World than there is today.
3. True or false? Humans have often migrated in search of land available for farming.
4. The Prime Meridian
A. measures distance from east to west.
B. is located near the equator.
C. is located at 0 degrees longitude.
D. measures distance from north to south.
5. At which location is the climate most likely to be temperate?
A. 5 degrees north latitude
B. 40 degrees north latitude
C. 25 degrees south latitude
D. 75 degrees south latitude
6. By comparison to a tropical ecosystem, a temperate ecosystem has
A. cooler temperatures and less rainfall.
B. less wind and more sunshine.
C. more frequent and more violent storms.
D. warmer nighttime temperatures.
Question 7 is based on the following passage.
The invasion of Russia in 1812 by French troops commanded by Napoleon ended in disaster. A main reason was that the French were unprepared for the Russian winter. They had expected fighting to end before winter began, and therefore did not have proper clothing or supplies. The French soldiers were still wearing summer uniforms when snow began falling. In the icy conditions, many died from hypothermia or starvation. As a result, the French were forced to retreat, and the campaign ended in failure.
7. Which of the following statements is supported by the passage?
A. The French retreated because they were outnumbered by the Russians.
B. Napoleon’s army was overwhelmed by the Russian climate.
C. The French invasion failed because the Russians had better generals.
D. The Russians considered the winter of 1812–1813 to be comparatively mild.
Answers are on page 828.