Chapter 18 Objectives Describe how humans use natural resources. Compare renewable resources with nonrenewable resources. Explain ways that humans can conserve natural resources. Section 1 Natural Resources

Chapter 18 Earth’s Resources A natural resource is any Earth-made material that is used by humans. Examples: water, wood, minerals, animals. Most resources are made into products that make our lives more easy. The energy we get from many of these resources originally comes from the sun’s energy. Section 1 Natural Resources

Chapter 18 Renewable Resources A renewable resource is a natural resource that can be made as fast as it is used. Although many resources are renewable, they still can be used up before they can be renewed. Trees, for example are renewable. However, some forests are being cut down faster than new forests can grow to replace them. Section 1 Natural Resources

Chapter 18 Nonrenewable Resources A nonrenewable resource is a resource that forms much slower than it is used. Coal, petroleum, and natural gas are examples of nonrenewable resources. When these resources are used up, humans will have to find other resources to replace them. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources Whether the natural resources you use are renewable or nonrenewable, you should be careful how you use them. To conserve natural resources, you should try to use them only when necessary. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources, continued Conserving resources also means taking care of the resources even when you are not using them. It is important to keep lakes, rivers, and other water resources free of pollution. Polluted water can harm plants and animals, including humans. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources, continued Energy Conservation The energy we use to heat our homes, drive our cars, and run our lights comes from natural resources. Most of the natural resources that provide us energy are nonrenewable resources. If we don’t limit our use of energy now, the resources may not be available in the future. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources, continued Conserving energy is important. You can conserve energy by being careful to use only the resources that you need. Turn off lights when you are not using them. Ride a bike, walk, or take a bus because these methods use fewer resources than a car. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources, continued Another way to conserve natural resources is to recycle. Recycling is the process of reusing materials from waste or scrap. Recycling reduces the amount of natural resources that must be obtained from the Earth. Recycling paper reduces the number of trees that must be cut down to make new paper products. Section 1 Natural Resources

Chapter 18 Conserving Natural Resources, continued Recycling also conserves energy. Energy is required to recycle materials, but it takes less energy to recycle an aluminum can than it does to make a new one. Newspaper, aluminum cans, most plastic containers, and some cardboard boxes can be recycled. Section 1 Natural Resources

Chapter 18 Objectives Describe what energy resources are. Identify three different forms of fossil fuels. Explain how fossil fuels form. Describe how fossil fuels are found and obtained. Identify four problems with fossil fuels. Section 2 Fossil Fuels

Chapter 18 Energy Resources The fuels used to run cars, ships, planes, and factories, and to generate electrical energy are energy resources. Energy resources are natural resources that humans use to generate energy. Most of the energy we use comes from a group of natural resources called fossil fuels. Section 2 Fossil Fuels

Chapter 18 Energy Resources, continued A fossil fuel is a nonrenewable energy resource formed from the remains of plants and animals that lived long ago. Petroleum, coal, and natural gas are examples of fossil fuels. Energy is released from fossil fuels when they are burned. But because fossil fuels are a nonrenewable resource, once they are burned, they are gone. Section 2 Fossil Fuels

Chapter 18 Types of Fossil Fuels All living things are made up of the element carbon. Since fossil fuels are formed from the remains of plants and animals, all fossil fuels are made of carbon, too. Different fossil fuels have different forms. Fossil fuels may exist as liquids, gases, or solids. Section 2 Fossil Fuels

Chapter 18 Types of Fossil Fuels, continued Liquid Fossil Fuels: Petroleum A liquid mixture of complex hydrocarbon compounds is called petroleum. Petroleum is also commonly known as crude oil. Petroleum is separated into several kinds of products in refineries. Those products include gasoline, jet fuel, kerosene, diesel fuel, and fuel oil. Section 2 Fossil Fuels

Chapter 18 Types of Fossil Fuels, continued More than 40% of the world’s energy comes from petroleum products. Petroleum products are the main fuel for forms of transportation, such as airplanes, trains, boats, and ships. Section 2 Fossil Fuels

Chapter 18 Types of Fossil Fuels, continued Gaseous Fossil Fuels: Natural Gas A gaseous mixture of hydrocarbons is called natural gas. Most natural gas is used for heating, but it is also used for generating electrical energy. An advantage of natural gas is that using it causes less air pollution than using oil does. However, natural gas is very flammable. Gas leaks can lead to fires or deadly explosions. Section 2 Fossil Fuels

Chapter 18 Types of Fossil Fuels, continued Solid Fossil Fuels: Coal The solid fossil fuel that humans use most is coal. Coal is a fossil fuel that is formed underground from partially decomposed plant material. Coal was once the major source of energy in the United States. People burned coal in stoves to heat their homes. Man trains in the 1800s and 1900s were powered by coal-burning steam locomotives. Section 2 Fossil Fuels

Chapter 18 How Do Fossil Fuels Form? Petroleum and Natural Gas Formation All types of fossil fuels form from the buried remains of ancient organisms. Petroleum and natural gas form mainly from the remains of microscopic sea organisms. When these organisms dies, the remains settle on the ocean floor where the remains decay and are buried to become part of the ocean sediment. Over time, the sediment slowly becomes rock, trapping the decayed remains. Section 2 Fossil Fuels

Chapter 18 How Do Fossil Fuels Form?, continued Through physical and chemical changes over millions of years, the remains become petroleum and natural gas. Section 2 Fossil Fuels

Chapter 18 How Do Fossil Fuels Form?, continued Coal Formation Coal forms underground over millions of years when pressure and heat cause changes in the remains of swamp plants. When plants die, they sink to the bottom of the swamp. If they do not decay completely, coal formation may begin. Section 2 Fossil Fuels

Chapter 18 Where Are Fossil Fuels Found? Fossil fuels are found in many parts of the world. The United States has large reserves of petroleum, natural gas, and coal. Section 2 Fossil Fuels

Chapter 18 How Do We Obtain Fossil Fuels? The kind and location of fuel determine the method used to remove the fuel. People remove petroleum and natural gas from Earth by drilling wells into rock that contains these resources. Section 2 Fossil Fuels

Chapter 18 How Do We Obtain Fossil Fuels?, continued People obtain coal either by mining deep beneath Earth’s surface or by surface mining. Surface mining, also known as strip mining, is the process by which soil and rock are stripped from the Earth’s surface to expose the underlying coal that is to be mined. Section 2 Fossil Fuels

Chapter 18 Problems with Fossil Fuels Although fossil fuels provide the energy we need, the methods of obtaining them and using them can have negative effects on the environment. When coal is burned without pollution controls, sulfur dioxide is released. Sulfur dioxide combines with moisture in the air to produce sulfuric acid. Section 2 Fossil Fuels

Chapter 18 Problems with Fossil Fuels, continued Sulfuric acid is one of the acids in acid precipitation. Acid precipitation is rain, sleet, or snow that has a high concentration of acids, often because of the pollution of the atmosphere. Acid precipitation negatively affects wildlife, plants, buildings, and other structures. Section 2 Fossil Fuels

Chapter 18 Problems with Fossil Fuels, continued Coal Mining Surface mining removes soil, if land is not properly restored afterward, surface mining can destroy wildlife habitats. Coal mining can also lower water tables and pollute water supplies. The potential for underground mines to collapse endangers the lives of miners. Section 2 Fossil Fuels

Chapter 18 Problems with Fossil Fuels, continued Petroleum Problems Producing, transporting, and using petroleum can cause environmental problems and endanger wildlife. In June 2000, an oil carrier sank off the coast of South Africa and spilled more than 400 tons of oil. The toxic oil coated thousands of blackfooted penguins. The oil hindered the penguins from swimming and catching fish for food. Section 2 Fossil Fuels

Chapter 18 Problems with Fossil Fuels, continued Smog The burning of petroleum products causes an environmental problem called smog. Smog is photo- chemical haze that forms when sunlight acts upon industrial pollutants and burning fuels. Smog is particularly serious in cities such as Houston and Los Angeles as a result of millions of automobiles that burn gasoline. Section 2 Fossil Fuels

Chapter 18 Objectives Describe alternatives to the use of fossil fuels. List the advantages and disadvantages of using alternative energy sources. Section 3 Alternative Resources

Chapter 18 Alternative Resources Most of our energy comes from fossil fuels. But they are nonrenewable and once they are used they won’t be available for thousands -- or even millions of years. Finding and using fossil fuels has environmental consequences. To continued to have fuels and not pollute the earth, we must find alternative sources of energy. The energy released by a fission or fusion reaction is nuclear energy. Section 3 Alternative Resources

Chapter 18 Pros and Cons of Nuclear Energy Nuclear power plants provide alternative sources of energy that can be used for a long time. However, nuclear power plants produce dangerous radioactive wastes that can remain dangerous for thousands of years. Section 3 Alternative Resources

Chapter 18 Pros and Cons of Nuclear Energy Another problem with nuclear power plants is the potential for accidental release of radiation into the environment. If a plant’s cooling system were to stop working, the plant would overheat. Then, its reactor could melt and a large amount of radiation could escape. Section 3 Alternative Resources

Chapter 18 Chemical Energy Some vehicles are powered by energy generated by fuel cells. Fuel cells power automobiles by converting chemical energy into electrical energy by reacting hydrogen and oxygen into water. Chemical energy is the energy released when a chemical compound reacts to produce new compounds. Section 3 Alternative Resources

Chapter 18 Chemical Energy, continued Once advantage of using fuel cells is that they do not create pollution -- the only byproduct is water. Fuel cells are also more efficient than internal combustion engines. The United States has been using fuel cells in space travel since the 1960s. One day, fuel-cell technology may be used to generate electrical energy in buildings, ships, and submarines. Section 3 Alternative Resources

Chapter 18 Solar Energy The renewable energy received by the Earth from the sun in the form of radiation is solar energy. The Earth gets more than enough solar energy to meet all of our energy needs. Solar energy can be used directly to heat buildings and generate electrical energy. However, we do not yet have the technology to generate the amount of electrical energy we need from solar energy. Section 3 Alternative Resources

Chapter 18 Solar Energy, continued Sunlight can be changed into electrical energy with Solar panels, which are large panels made up of many solar cells wired together. Solar panels mounted on the roofs of some homes and businesses provide some of the electrical energy used in the buildings. Section 3 Alternative Resources

Chapter 18 Solar Energy, continued Pros and Cons of Solar Energy One of the best things about solar energy is that it doesn’t produce pollution and it is renewable. Solar panels are more expensive to make than other energy systems and some climates aren’t sunny enough for them to work efficently. Section 3 Alternative Resources

Chapter 18 Wind Power Wind power is the use of a windmill to drive an electric generator. Wind energy is renewable, and it doesn’t cause any pollution. However, in many areas, the wind isn’t strong enough to create a lot of energy. Section 3 Alternative Resources

Chapter 18 Hydroelectric Energy Electrical energy that is produced by falling water is called hydroelectric energy. Falling water turns turbines inside hydroelectric dams and generates electrical energy for millions of people. Section 3 Alternative Resources

Chapter 18 Hydroelectric Energy, continued Pros and Cons of Hydroelectric Energy After the dam is built, hydroelectric energy is inexpensive, renewable, and causes little pollution. However, hydroelectric energy can be produced only where large volumes of falling water can be harnessed and dams can be built. Section 3 Alternative Resources

Chapter 18 Hydroelectric Energy, continued Building large dams necessary for hydroelectric power plants often destroys other resources, such as forests and wildlife habitats. Large numbers of fish die each year because their migratory paths is disrupted by damns. Dams can also decrease water quality and create erosion problems. Section 3 Alternative Resources

Chapter 18 Power from Plants Plants are similar to solar collectors in that both absorb energy from the sun and store it for later use. Leaves, wood, and other parts of plants contain the store energy. Even the dung of plant-grazing animals is high in stored energy. These sources of energy are called biomass. Biomass is organic matter that can be a source of energy. Section 3 Alternative Resources

Chapter 18 Power from Plants, continued Burning Biomass The most common way to release biomass energy is to burn it. About half of the world’s population burn wood or charcoal to heat their homes and cook their food. Scientists estimate that the burning of wood and animal dung accounts for approximately 14% of the world’s total energy use. Section 3 Alternative Resources

Chapter 18 Power from Plants, continued Gasohol Plants that contain sugar or starch can be made into alcohol. The alcohol can be burned as a fuel, or the alcohol can be mixed with gasoline to make a fuel called gasohol. Biomass is a renewable source of energy. However, producing biomass requires land that could be used for growing food. Section 3 Alternative Resources

Chapter 18 Energy from Within Earth Geothermal Energy The energy produced by the heat within the Earth is called geothermal energy. Groundwater is heated by magma and becomes steam. Steam is used to turn generators to make electricity. Geysers are natural vents that discharge this steam or water in a column into the air. Section 3 Alternative Resources

Chapter 18 Energy from Within Earth, continued The steam and hot water can also escape through wells drilled into the rock. From these wells, geothermal power plants can harness the energy from within Earth by pumping the steam and hot water. Section 3 Alternative Resources