World Population Growth Over Time
The world population has increased a lot in the 20th century and is projected to grow exponentially in the 21st century; mostly in the developing regions. This growth rate is shown with a simple two-dimensional (2D) graph that depicts the population growth as a function of time. The independent variable is time (in years) plotted on the x-axis and the dependent variable is population (in billions of people) located on the y-axis. Note that two graphs have actually been plotted in the figure; population growth verses time for developed regions and population growth verses time for the world. The part of the total population attributed to developed regions is represented in gold and the part for developing regions in green. The dashed line is a prediction based on available data that assumes finite resources (Ref ).
A well designed graph, as shown here, can be a powerful tool to show a trend over a period of time.
Copyright © 1998 Central Virginia Governor's School for Science and Technology Lynchburg, VA