
Purpose
To help students investigate the causes and consequences of population growth and the environmental factors that contribute to it.
Context
This lesson is part of a group of lessons that focus on the social, behavioral, and economic sciences. These lessons are developed by AAAS and funded by the National Science Foundation Grant No. SES-0549096. For more lessons and activities that take a closer look at the social, behavioral, and economic sciences, be sure to check out the SBE Project page.
Read MoreMotivation
Begin the lesson by writing “Population of the World” on the board with the following timeline provided by About.com: Geography: 1900—1.6 billion; 1950—2.5 billion; 1980—4.4 billion; 2000—6 billion; 2050—?
Have students discuss in small groups what they think the world’s population will be in 2050 and what factors influenced their predictions.
Inform the class at an appropriate time that experts believe the world population will be 9.2 billion by 2050—almost a third more people than there are today.
Questions for them to consider may include:
- What do you think daily life might be like in your town in 2050?
- What types of technological changes will be needed to accommodate the world’s population growth in 2050?
- What do you think will be the greatest environmental concerns at that time?
- Do you see population growth becoming a major political issue by 2050? Why or why not? What types of population-related issues might people be talking about at that time?
(Accept all reasonable answers. Encourage groups to elaborate on their responses.)
Development
Have students use their Population Dynamics student esheet and go to and read Population Studies which has a good overview of factors influencing population growth.
When they are finished, lead a discussion addressing questions like these:
- Why do you think most of the huge growth of the world’s population between 1900 and 2000 (from 1.6 to 6 billion people) occurred after World War II? (Answers will vary. Many people were killed during WWI and WWII, which dominated most of the early part of the 20th century. Improved nutrition and healthcare that came afterward helped people to live longer, while peace and global economic growth also contributed to family and population growth.)
- What factors contributed to the doubling of life expectancy during this period? (The agricultural revolution and the availability of antibiotics, vaccines, and pesticides contributed to the increase in life expectancy.)
- What does “population momentum” mean? (It means that a large percentage of a population is reaching child-bearing age and that the population is, therefore, likely to increase dramatically.)
- What impact does industrialization appear to have on population growth rates? (Statistics show that, as countries become industrialized, women tend to have fewer children. Rates have dropped from nearly 5 births per woman in 1970 to 2.7 births currently.)
- What concern does the aging population pose for the governments of many countries? (With increasing proportions of populations growing old and living longer, there will be fewer workers contributing to social security and other similar programs designed to reimburse retired people. Many governments may not have the means to support them.)
Next, divide the class into three groups and make these assignments from the DEPweb, from the World Bank:
- Group 1: Read Did You Know?, which covers the effect of income on population growth and representation of change by graphing
- Group 2: Read Population momentum, dealing with the influence of age, gender, and urbanization of population growth and representation of change by graphing
- Group 3: Read Population growth, the economy, and the environment, which presents information regarding environmental factors affecting population growth and social strategies for controlling it
Have students read the instructions for their particular group. Remind groups 1 and 2 to click on the hyperlinks for the charts to view them clearly. They also should click to find out more about any of the highlighted terms. Have group 3 click on the four hyperlinks on page 3—GNP per capita, access to safe water, deforestation, and desertification—to learn more about them and their influence on population growth.
Pass out the appropriate Population Growth Group student sheets to each group and have students collaborate on answering the questions on their sheet. (Answers to these questions have been provided on a corresponding teacher answer sheet.) When all the groups have finished, they should be prepared to present a summary of their reading and the answers to their questions to the class. Have students take notes on the other groups’ presentations. Encourage groups to direct others to specific graphs, charts, or maps that support their presentation.
Finally, have the entire class discuss how all the human, social, economic, and environmental variables they have learned about interact and can be made to work together to control population growth.
To check their comprehension and reinforce what they have learned, you also may find it useful to ask the class review questions from the Exercises section at the end of Population Growth Rate: Text Exercises with Answers. Be sure to discuss as a class specific graphs, charts, or maps to give students a greater understanding and opportunity to explore their usefulness in portraying patterns of population growth.
Assessment
Have students write a letter to their congressperson or local newspaper summarizing the problem of population growth and highlighting a specific, realistic action the government or individual citizens can take to help keep earth and its people in balance. Instruct them to include graphs in describing both the problem and its proposed solution.
Extensions
Students may enjoy the Census Bureau’s colorful and informative IDB Population Pyramids (select population pyramid graph from the Select Report dropdown menu), which provide a fun and easy way to visualize population dynamics (in animated pyramid graphs). Users can select any country and track incremental population growth changes based on gender and age up to the year 2050.
Students may enjoy gaining an in-depth understanding of population growth trends in the U.S. by visiting the Census Bureau’s CensusScope. Using current census data and a variety of graphs and maps, CensusScope provides a considerable amount of information and analysis on growth trends based on age, race, households, occupation, and many other factors.
A visit to Sprawl City can help students develop a keener understanding of how population and consumption growth cause cities to grow outward and ultimately destroy surrounding habitats and ecosystems.