1. Objectives:
Understand the relationship between population growth and land use
Learn that only 1/32 of Earth's surface is available to grow our food
Learn what portions of Earth are oceans, inhospitable land, and
non-arable land
Understand carrying capacity
2. Correlations
Computation
Deductive and inductive reasoning to generate hypotheses
Extract information from graphs
Graph relations and functions
Use mathematical expectation to judge possible outcomes
3. Excercices.
(You'll need: an apple, a knife, some graph paper, and some Worksheets.)
1. The apple is to represent Earth. Slice the apple into quarters. Save one quarter. It represents the total land area of the earth. What do the remaining quarters represent? [the oceans of the world]
2. Slice the land quarter in half. Set aside one of the pieces. The portion set aside represents the land area that is inhospitable to people. What comprises it? [the polar areas, deserts, swamps, high or rocky mountains] What fraction is left? [1/8] It represents human habitat - land where people live but do not grow the food.
3. Slice the remaining 1/8 piece into four equal sections and set aside three of these. What fraction is left? [1/32] The three 1/32 pieces set aside represent areas too rocky, too wet, too cold, too steep, or with soil too poor to produce food. They also contain the cities, suburban sprawl, highways, shopping centers, schools, parks, factories, parking lots, and other places where people live but do not grow food.
4. Carefully peel the skin off the 1/32 slice. This represents the food-producing soil upon which humankind depends. It is a fixed amount of land with topsoil less than five feet deep. Although advanced agricultural technology has increased food production per acre, each person's share of this food-producing land becomes smaller as the population increases.
5. Familiarize yourself with the Worksheet by reviewing the term "carrying capacity". Earth is comprised of about 34 billion acres of land. As the population grows, each of our shares of land decreases. However, it is difficult to assess the amount of land we each need because the term is relative to our values and standard of living. Determine land area per person, keeping in mind that not all land is habitable.
Why is it important to protect our natural resources? What types of development threaten these resources? How does population growth impact these resources? Discuss the difference in the impact on resources from industrialized countries versus less developed countries.
Note: This model does not account for fish production from the 3/4 of the area representing the Earth's oceans. However, only approximately 1/10 of the ocean area produces fish that people eat and many species have been depleted and are in danger of becoming extinct due to over-harvesting. |
