Name: __________________________________
TOC#___
Human Population Growth
Part I: Human population growth throughout history
Earth's Carrying Capacity: Prior to 1950, the death rate was high, which kept human population from increasing
rapidly. Throughout history things like the agricultural revolution, the industrial revolution, advances in
medicine, sanitation and nutrition have decreased the death rate. The human population is now growing rapidly.
Will the population grow forever? All population are limited by factors such as space, amount of food and
disease. The carrying capacity is the number of individuals that a stable environment can support. What is the
human population carry capacity? 8 billion? 10 billion? People disagree. As the population approaches its limit,
starvation will increase. Some countries have a much higher growth rate than others. Growth rate is the number
of people born minus the number of people that die.
Most countries are trying to reduce their growth rate. Zero population growth means that as many people are
being born as there are dying - to achieve zero population growth, each couple would need to have no more than
two children (to replace the parents). Even if this number is achieved, the population will continue to grow
because the parents will still live on for decades, as their children have children and their children have children,
and so forth.
Use the data on the below to graph the human population growth over time. Please extend your number of
people out to 10 billion and continue your graph with your prediction of what will happen.
Year
A.D.
Number
of
People
(in
billions)
1650
.50
1750
.70
1850
1.0
1925
2.0
1956
2.5
1966
3.3
1970
3.6
1974
3.9
1976
4.0
1980
4.4
1991
5.5
2000
6.0
2004
6.4
2008
6.7
2010
6.97
2013
7.1
Name: __________________________________
TOC#___
Use the graph on the previous page to answer the analysis questions below.
1. What factors contributed to the world's overall population growth in the last 150 years?
2. What factors do you think will contribute to whether the human population will continue to grow or not?
3. If the carrying capacity of the earth was 9 billion people, when would this number be reached (according
to your graph)?
4. What will happen when the human population exceeds the earth's carrying capacity?
Part II: Population growth in different areas of the world
The population in different countries is dependent upon many things. Answer the following questions
1. Afghanistan has a fertility rate of approximately 5.5 children per mother, while Switzerland has a
fertility rate of approximately 1.5 children per mother. What factors do you think lead to these
differences?
2. How will these different fertility rates affect the overall human population size?
3. What other factors do you think could affect the overall population size? Think back to the People Bomb
reading
Name: __________________________________
TOC#___
Part III: Age Structure Diagrams: Developing countries usually have more rapid population growth than
developed countries. Population growth depends, in part, on how many people of different ages make up a
given population. Demographers can predict future growth using models called age-structure diagrams. Agestructure diagrams show the population of a country broken down by gender and age group
1. Describe what an age-structure diagram is in your own words.
Below are three age structure diagrams. The y-axis shows the age, the x-axis shows the number of people in
each age range. On either side it shows what amount is male, and what amount is female.
A population like that depicted in the age-structure of diagram A will grow rapidly, and population depicted by
diagram b will grow slowly, and a population like that depicted in diagram c will have a decline in growth.
2. In complete sentences, explain why you think the population grows rapidly in diagram A.
3. In complete sentences, explain why you think the population grows slowly in diagram B.
4. In complete sentences, explain why you think the population declines in growth in diagram C.
Name: __________________________________
TOC#___
On the following age structure diagrams:
A. predict if their population is growing rapidly, slowly, or declining.
B. Explain why you think the population will be larger or smaller in 25 years. Make your predictions based
on the population in 25 years.
A. _____________________
B. _____________________
___________________________
___________________________
___________________________
___________________________
___________________________
A. _____________________
B. _____________________
___________________________
___________________________
___________________________
___________________________
___________________________
A. _____________________
B. _____________________
___________________________
___________________________
___________________________
___________________________
___________________________