ECOLOGY AND THE CONSERVATION OF NATURAL RESOURCES
|Energy Resources and Demands
|Science in Society
||Personal Needs 4.2b
To develop an understanding of the interdependence of all organisms and the need for conserving natural resources
An adequate and continuous supply of soil, water, air, and energy are essential to the survival of living things.
Ecology O6.00 To understand the role of fossil fuels and energy conservation
INSTRUCTIONAL OBJECTIVES: The learner will:
OUTLINE OF CONTENT:
I. Fossil fuels and their uses
II. Conservation of fossil fuels
B. Natural gas in formation of fossil fuels
3. Jet fuel
4. Heating oil
5. Motor oil
6. Road tar
1. Used to produce steam for electricity
2. Substitute for other fuels (except motor vehicles and aircraft)
A. Current consumption rate
1. Oil supplies will last 60 years
2. Natural gas will last 46-62 years
3. Coal will last 200-300 years
COMPONENT OF SCIENCE: Science in Society
To enable students to demonstrate positive attitudes toward science in solving problems and making personal decisions about issues affecting the individual, society and the environment.
4.2 PERSONAL NEEDS - The application of science may be used to change the quality of life for the individual.
STANDARD: The learner will understand that:
4.2b - Science concepts may be applied to personal decisions.
BENCHMARK: Individual behavior may be influenced by an understanding of science concepts.
MATERIALS: Peat moss, lumps of coal, clear bottles with various oils and oil derivatives
On your paper answer these questions: What makes automobiles go? Where does your heat come from? What is used to manufacture steel? What fuel do you use to cook with? Your answers probably included at least one of these: natural gas, coal, petroleum. These are fossil fuels. Today we are going to learn what fossil fuels are and what they are used for.
Fossil fuels result from the remains of ancient plant and animal life that have been transformed into coal, oil, and natural gas. Coal is found in the earth's crust in the form of distinct layers, and oil and natural gas are trapped in permeable sedimentary rock.
When we burn coal, we are actually releasing solar energy that was stored in vegetation through photosynthesis tens or even hundreds of millions of years ago. Over many centuries, as giant tree fern and other plants died, a thick vegetative mat accumulated in swampy waters. High concentrations of carbon were gradually produced as a result of the partial decomposition of the matted plant remains by anaerobic bacteria. Eventually, the mass of highly carbonized, partially decomposed plant materials (which we call peat) was further compacted under the weight of more sediment and plant remains. Then the increasing heat and pressure transformed the peat into coal.
Like coal, the oil and natural gas that constitute petroleum are organic in origin. Oil is a mixture of thousands of different hydrocarbon molecules and other organic molecules. Natural gas is actually a mixture of gases that have formed.
Petroleum is perhaps the most versatile fossil fuel. Crude oil as it is pumped from the ground, is a heavy, gooey, viscous, dark liquid. The oil is refined to produce many different materials such as propane, gasoline, jet fuel, heating oil, motor oil, and road tar. We all use one or more of these daily. Some of the chemicals in the oil are extracted and used for the manufacture of plastics and medicine. Just think of how many things you use that are made of plastic. Let's make a list of all things you use that are made of plastic. It is difficult to imagine what would happen to our civilization if the supply of liquid fuels ran out.
Natural gas is an ideal fuel because it is clean burning, producing only carbon dioxide and water as end products. Natural gas is also transported easily by pipelines directly where it is needed and where it can be used more efficiently than if it were first converted to electricity. Natural gas is the safest fossil fuel in terms of the number of accidents and deaths that are caused during its extraction and use.
Coal is primarily used today to produce steam that generates electricity. Coal can also be used directly as a substitute for other fuels. Does anyone know someone that uses now, or used to, burn coal in a stove for heat? Perhaps your grandparents might have. In terms of economics, environmental considerations, and convenience, it is not advantageous in rail transportation, residential, commercial, or small industrial use. However, coal has a big competitive advantage in the generation of electricity because it can be delivered to utility plants at a very low cost per unit of energy.
Trace the energy from your home to its source.
(Calculate how many gallons of gas are used per week by the families in the entire class.)
How many more years do you think you will live? Can you imagine living those years without automobiles, airplanes, or electricity? These things come from fossil fuels. Fossil fuels are not an unlimited resource. Today we are going to learn how limited these resources are.
One of the most important questions of our times, and one of the most difficult to answer with any real confidence, concerns how long our fossil fuel supplies will last. For a realistic estimate of the number of years remaining before all the earth's fossil fuels are gone, the reserve of fuel must be estimated, human population growth must be forecast, and the future rate of consumption must be predicted. All such forecasts are subject to large errors.
The most reasonable method of estimating the energy requirements from the 1980's into the early twenty-first century is to graph past energy consumption and then try to guess how the curve will continue. In the 1970's countries that owned fossil fuel reserves began to realize how valuable their fuels were, so they raised their prices. As prices went up, consumers started to use less fuel. People drove fewer miles and purchased smaller, more fuel-efficient cars. They added insulation to buildings and saved in many other ways. These conservation measures resulted in a decline of energy use between 1973 and 1975. In the years between 1975 and 1988, the costs of energy and energy consumption have fluctuated. What is the cheapest price for gasoline that you can remember paying? What was the highest price?
After projecting these trends and considering known reserves, our oil supplies are considered to last only into the first part of the next century. Some scientists predict supply will fail to meet demand shortly after the year 2000. Others give a possible 40 or 50 more years.
Since natural gas is a desirable fuel, global consumption is increasing. Taking all factors of consumption and unfound resources thought to be available this fuel can expect to last until about 2060. Larger reserves of coal exist in many parts of the world. Availability of this fuel can be expected to last until the year 2200. However, there are problems with coal. More air pollutants are released from burning coal then from oil or gas. Another difficulty arises because coal cannot be used directly in conventional automobiles, in most home furnaces, or in many industries.
Another problem is transporting coal. The location of coal is usually in western areas and must be moved across country to the east. The cost of transporting this coal accounts for 73% of its final cost. Because of the increased rail transport of western coal, more towns have requested that railroads be rerouted around them to avoid an interruption of local traffic patterns. Coal trains are about a mile long and take several minutes to pass a highway crossing. In the eastern United States, canals and locks must be enlarged to handle the larger barges that are required to haul the amount of coal that is needed to meet the increased demand.
Pick the most promising source of energy for the United States and discuss the good points and the bad points related to that energy source including such things a plentifulness, easy of obtaining, value, etc. Do you still think it is the most promising source of energy for the United States?
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