Population Growth and Global Society


This lab will explore the role of population growth in our changing world. We will explore population growth by examining the population pyramid of different countries and discussing an article by the World Watch Institute entitled Rethinking Population, Improving Lives. Increasingly we can see the connections between human population growth, ecological degradation, gender inequality and global security. By exploring the connections between these factors we will develop and discuss potential solutions to this growing problem.


Before Coming to Class

First, read through this lab for some background on human population growth and an introduction to the concept of population pyramids. Then read Rethinking Population, Improving Lives (Chapter 6, 2002 p. 127-148, WorldWatch Institute). This article examines the history of population growth as well as the causes and consequences of the recent rapid increase in the human population. The article also explores how politics plays a role in population as well as the importance of empowering women. Come to class ready for a lively discussion about the future of the human population.



Figure 2: World population growth from 1750 to 2150 (UN)


Introduction to Human Population Growth

For most of our history, the human population had less than 10 million people. However, as communities developed agriculture, this lead to a dramatic increase in population. In the year 2000, the human population grew to more than 6.1 billion people. The human population could increase to more than 9 billion in the next 50 years. Most of this population growth is occurring in less developed countries (Figure 2).


Population Pyramids

A population pyramid is a graphical representation of the age and sex of a given population. The shape of the pyramid shows the populations potential for future growth and facilitates comparisons between nations over time. Horizontal bars represent the numbers of males and females in each age group. The left side of the pyramid generally represents the male population and the right side shows the female population. The sum of all the age-sex groups in the population pyramid equals 100% of the total population. The bars on the left at the bottom of the pyramid represent the proportion of the population that is male, 0-4 years old and the bars on the right show the proportion of the population that is female, 0-4 years old. Each bar above the base represents the next five-year group, in the population. As each group ages, it may lose members from death, or it may gain or lose members due to migration (PRB, 2005).



Figure 3: Population pyramids for rapidly growing, slow growing, and negatively growing populations (UN).


A rapidly growing population, such as the Democratic Republic of Congo will have a classic pyramid shape with many young people at the base and few old people at the top. Many developing countries with high birth rates demonstrate this type of population distribution. A slowly growing population such as the United States will have a more columnar shape to the pyramid. Some developed countries show this type of distribution because migration allows the population to grow despite low birth rates. A country that has negative population growth (couples are having less than two children or replacement of themselves) has less young people than old people. Many developed countries with low rates of immigration show this type of population distribution (Figure 6.c.3).


You can explore the population pyramids for other countries using this site: https://www.populationpyramid.net/


In Class

Each student should download the world population data from Canvas (Human_Population.xlsx) or here. Using Microsoft Excel, create a graph that plots the data provided and use it to predict the world population for in 2025, 2050, and 2075; for reference, the data table includes the UN's 2100 projection. (Hint: Start by looking at the yearly change in population.) Be prepared to present your predictions and explain how you approached the problem. Next, in groups of two, students should develop a problems and solutions grid for each type of population pyramid (rapidly growing, slowing growing and negatively growing populations). Be prepared to present and discuss your team’s grid with the class. Next, discuss the following questions related to the Rethinking Population, Improving Lives article.


Question 1

The extreme difference between population and birth rates in wealthy and poor nations creates the conditions for an increased flow of people across international borders in coming decades. What consequences might arise from this type of migration? What benefits might occur from increased migration and cultural mixing?


Question 2

By 2050, global population is expected to reach 7.9-10.9 billion people with most expected to be living in urban areas. What types of social changes might take place from this increased urbanization? 


Question 3

The number of people on Earth combined with the level of consumption and technological capability largely determines ecological resource exploitation. Is population control, decreased consumption or technological innovation the most effective way to conserve our natural resources?


Question 4

Natural resource shortages due to population growth and over-exploitation are leading to tension over those resources shared by peoples and nations. Examples of this include conflicts over rivers like the Nile and Ganges, as well as land in Sudan. Given the need for land, fresh water and other natural resources, and the increasing number of people needing to share the supply, what measures can be implemented to conserve and protect these natural resources? What policies should be implemented to avoid conflict and wars over natural resources?


Question 5

As the human population increases and people become more urbanized, epidemiologists are increasingly seeing the spread of infectious disease. What measures can be employed to prevent the spread of potentially deadly infectious diseases? 


Question 6

What are the costs and benefits of implementing contraceptive and family planning education in the developing world? Given that access to contraceptives and reproductive health services is lowest in the money-strapped developing world, does the international community have a responsibility to provide the means to help implement and maintain these programs? 


Question 7

What are the potential outcomes of having large groups of unemployed youth with little prospects for economic opportunities? What measures could be employed to prevent or mend this situation?


Question 8

What role does religion have to play in reproductive issues?


Question 9

How do societies benefit from women gaining access to more education, civil liberties, economic opportunities, and political and social power?


Question 10

It is increasingly clear that the long-term future of environmental and human health is dependent on the empowerment of women. What political and social steps can be taken to improve access to education, economics, political power and civic freedom for women?