Part 1: Graph the human population using Excel

1. Copy and paste the data above into an Excel worksheet (include the column titles).

2. Select all of the data (including the titles) and click on the Insert toolbar

3. Select the icon next to recommended charts that says Insert XY Scatter Plot – this should create the graph for you.

4. Double click on one of the horizontal axis numbers – this will open up a sidebar that allows you to change the axis. Minimum can be 1500, Maximum 2100.

5. Copy the resulting graph and paste here (15):

Analysis

1. It took 1649 years for the world’s population to double, going from .25 billion people to .50 billion people. How long did it take for the population to double once again? (5)

2. How long did it take for the population to double a second time? (5)

3. A third time? (5)

4. According to this information, the human population has increased / decreased (highlight one) at a decelerated / accelerated rate (highlight one) (10)

5. Based on your graph, in what year will the population reach 8 billion? (5)

6. Based on your graph, how many years will it take for the population of 2004 to double? (5)

The Earth’s Carrying Capacity

Prior to 1950, the death rate was high, which kept the numbers of humans from increasing rapidly. In the 19th Century, the agricultural revolution increased food production. The industrial revolution improved methods of transporting food and other good. In the 20th Century, advances in medicine, sanitation and nutrition have decreased the death rates further. These factors combined to produce the rapid growth of the human population in the 20th century.

As with any population, humans are also 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. Authorities disagree on the maximum number of people that the earth can support, though the numbers generally range for 8 to 10 billion. 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. Compare the growth rates of the following countries

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. The United States reached zero population growth in the 1980’s, and yet the overall population of the US still increases.

Analysis

1. What factors contributed to the world’s overall population growth in the last 150 years. (10)

2. Why does a population not level off during the same year it reaches zero population growth? (10)

3. If the carrying capacity of the earth was 9 billion people, when would this number is reached (according to your graph)? (10)

4. What will happen when the human population exceeds the earth’s carrying capacity? (10)

5. Based on what you have learned about human population and carrying capacity, what prediction(s) would you make about the future of the human population? (10)