World Population Growth - Page | 1
World Population Growth
Purpose:
 Graph and mathematically analyze the rates of human population growth through history.
 Project human populations into the future based on generalization from various data source for
modern times.
Introduction
There is a close connection between the human population of the Earth and many of the problems we
currently face as a global society. Issues such as resource depletion, energy consumption, global food
supplies, drinking water reserves, soil erosion, water and air pollution, global climate patterns, and
many others are directly related to the growing number of people living on our planet.
Fig. 1-1
This long range
population projection,
from United Nations
sources, focuses on
divergent trends
between industrialized
and less-developed
nations.
As seen in Figure 1.1, since about 1950 differing population trends between the developing and
industrialized regions of the world have further complicated the situation. In this exercise you will
examine human growth trends closely and draw conclusions about population numbers – and
problems – in the coming generations.
Materials:
 graphing paper or Excel software
 Internet access
World Population Growth - Page | 2
Exercise I: Historical Overview and Application
Procedure:
1. Plot the data below on a piece of graph paper. These are good estimates of world population at
various times since the beginning of human civilization.
Year
Population
8000 BC
4000 BC
500 BC
AD 500
AD 1000
AD 1500
AD 1700
AD 1900
AD 1950
AD 1980
AD 2000
Note: If using Excel, substitute the directions in the
box for steps 2-4 below.
2. Plot years along the x-axis and label this axis
Time. Start at 8000 BC, letting each inch
equal 1000 years. Attention: Set your scales
carefully, the data points are not uniformly
spaced.
3. Label and plot the population, in billions,
along the y-axis. If you are using graph paper
ruled in inches, let each inch equal 1 billion
people. Each tenth of an inch then equals 100
million people. Lab Hint: Data for the earliest
years will be difficult to plot exactly to this
scale. If available, metric ruled graph paper is
easier to use.
4. Draw a smooth line that best connects all the
data points.
4 million
7 million
100 million
200 million
250 million
400 million
600 million
1.6 billion
2.5 billion
4.5 billion
6.1 billion
Excel Directions:
Open the file “population data” from
NetClassroom. The data have been entered
already. Note that the BC dates have been
entered as negative values for ease of
plotting.
a. First, convert the population data
from millions of people to billions of
people.(This may be done for you.)
b. Select year data and the population
data (in billions) including the header
row.
c. Go to the Insert tab and select
Scatter from the Charts menu.
d. Select Scatter with Smooth Lines
and Markers. This will construct a
graph with time on the x-axis and
population on the y-axis. All of the
points will be connected.
World Population Growth - Page | 3
Analysis:
Answer the following questions using the graph that you constructed. The questions are listed on the next
page for you to answer in Word and e-mail to me.
1. Examine the shape of the plotted line on your graph.
a. What type of mathematical relationship exists between human population and time?
b. Identify and describe the regions of the graph that represent the Lag Phase, Growth Phase,
and the Stationary Phase.
c. Define what is meant by the terms “J” curve and “S” curve. Review pp. 163-164 in your
text for help.
2. Analyze the patterns of growth after 2000.
a. Predict the world’s population in the year 2050 and plot it.
Excel Directions:
Open the file “population data” from NetClassroom.
a. Enter desired year in cell A14. In this case type “2050” without the quotes
into cell A14.
b. Insert the following formula, without the parentheses, into box B14:
=GROWTH(B9:B13,A9:A13,A14,TRUE)
c.
The number in box B14 shows the predicted exponential growth of the world
population (in millions) for the year entered in box A14 based on the actual
data from the past century. If you change the year in box A14, the world
population value will change accordingly.
b. Explain why this value may be realistic. Also give a reason why it may not be.
c. Describe how three environmental problems we now face would change if your predicted
value came true.
3. Estimate as best you can the doubling time (in years) for the population after each period:
a. 8000 BC _________
500 BC ________
1700 BC _________ 1900 ________
1950
_________
1980 ________
2000
_________
b. Is the doubling time at each of the above points in history getting longer or shorter?
c. Read “Doubling Time and Exponential Growth” on page 11 of your text. Using the “Rule of
70,” calculate the rate of population growth for each of the above intervals. Show your
calculations.
d. Graph the doubling times over time.
e. Use your graph of doubling times to predict the rate of growth and the population in the year
2050.
References
Population Growth Over Human History (1996)
http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html