The earth as an apple
Consider the earth as an apple. Get
an apple and do the following sequence, or read the activity
slowly and imagine or draw each action.
Slice an apple into quarters. Set aside three of the quarters.
These represent the oceans of the world. The fourth quarter roughly
represents the total land area left.
Slice this land quarter in half, giving you two 1/8th world pieces.
Set aside one piece. This is land inhospitable to people (polar
areas, deserts, swamps, very high or rocky mountainous areas.)
The other 1/8th piece is the land area where people live, but
does not necessarily grow the foods needed for life.
Now slice this 1/8th piece into four sections, giving you four
1/32nd pieces. Set aside three of these pieces. These are areas
too rocky, too wet, too cold, too steep., or with soil too poor
to produce food, They also include the areas of land that could
produce food but are buried under cities, highways, suburban
developments, shopping centers, and other structures that people
have built.
This leaves a 1/32nd slice of the earth. Carefully peel this
slice. This tiny bit of peeling represents the surface, the very
thin skin of the earth's crust upon which humankind depends.
Less than five feet deep, it is a fixed amount of food-producing
land.
When we see the small amount of land that produces our food,
it's easy to see that protecting land resources are important.
Advanced agricultural technology has enabled the world to feed
may of its people. But, with a fixed land resource base and an
ever-increasing number of people trying to feed themselves from
the fixed base, each person's portion becomes smaller and smaller
and more important to the individual person. We must protect
the environmental quality of our air, water, and land.
Remember: It takes 100 years to
make 1 inch of top soil.
The water we have on earth today is all the water we'll ever
have.
Earth's water is composed of
97.2 salt water
2.15 ice
0.63 ground water
0.02 surface water (lakes, rivers)
Only the last two provide our useable
water.
Adapted from Idaho Ag in the Classroom Curriculum Guide.
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