Global Picture
Between 1850 and 1970, the number of people living on Earth more than tripled, and energy use increased twelvefold. All over the world, people are plugged in. With population growth and increasing ways to use energy, people are really straining the Earth's resources.
When teaching young children about energy, be sure to remind them about the dangers of electrical outlets and exposed wiring. They should never touch anything electrical without adult supervision.
The End of the Age of Oil
Oil is the world's number-one source of commercial energy. It powers almost all machines that move. But oil is a fossil fuel and it will run out. People have to find new sources of energy, as well as learn to better conserve energy. Consider these facts:
The United States consumes 25 percent of the world's oil, and 70 percent of that is imported.
Over the years Americans have driven larger and less fuel-efficient cars and bought bigger homes with more appliances. As a result, U.S. oil use increased in the last decade by nearly 2.7 million barrels a day — more oil than is used daily in India and Pakistan combined, which together contain more than four times as many people as the United States does. Recently, that trend has slowed due to the lack of and the expense of oil.
In the early 2000s the average American consumed five times more energy than the average global citizen, ten times more than the average Chinese, and nearly twenty times more than the average Indian. If the average Chinese person used as much oil as the average American uses, China would require 90 million barrels per day — that's 11 million more than the entire world produced each day in 2001.
It is a very similar story for coal, the number-one global source of electricity. What's the world to do when the oil and coal run out? Assign small groups of students to explore alternative fuels and ideas that countries around the globe are creating to address the end of fossil fuels. For example, the European Union is talking about using a small section of the Sahara Desert for a solar field. It is an intensely sunny place with such vast unused space, so it is an ideal spot to harness solar energy. Supporters of the plan believe the Saharan solar panels could harness enough solar energy to power all of Europe! Almost all of Iceland's energy comes from geothermal power and hydroelectricity. How do they get so much power from these renewable sources?
According to the U.S. Department of Transportation, Americans drove 1.4 billion fewer highway miles in April 2008 than they did in April 2007. Discuss why this happened. Is it because more people are trying to reduce exhaust emissions? Is it because oil prices went up? How much does a gallon of gas cost you now compared to one year ago?
A Wave of Energy
Oceans cover three-quarters of the Earth's surface. There is tremendous energy in ocean waves. Waves are caused by the wind blowing over the surface of the ocean. There are methods for harnessing the action of waves to generate energy production. Small, onshore wave-energy sites can produce enough energy to power local communities. Japan and Scotland have active wave-energy programs.
Demonstrate the power of waves by using a large pan of water and an electric fan. What do your students think will happen to the water after you turn on the fan? Can you make things move in the water because of the movement of the water (not because of the wind)? Try objects that lie flat on the top of the water, such as small pieces of wood or cardboard. Can you predict what will happen?
