Presentation on theme: "Resources for Energy State Objective 4.d.. What are Resources? Natural resources are the parts of the environment that are useful or necessary for the."— Presentation transcript:
Most energy used by humans comes from fossil fuels. Energy Use
Fossil Fuels Made of hydrocarbons, compounds that contain carbon and hydrogen atoms. Combustion is the process of burning fossil fuels to release energy. –Carbon dioxide and water are two other products of combustion.
Coal Coal is a sedimentary rock formed from dead plant matter that is buried underwater –Most is used for electrical power plants.
Petroleum (Oil) Petroleum (oil) is a mineral made from the remains of dead marine organisms buried in Earth’s crust. –Provides one-third of world’s energy. –Can be turned into gasoline, diesel fuel, paints, and plastics.
Natural Gas Natural gas is a colorless, odorless gas made mostly of methane –Made mostly of methane but contains other gases. –Often found with oil deposits.
Alternative Energy Sources Why is it important that we find alternatives to fossil fuels? Give at least three reasons.
Alternative Energy Sources Hydroelectric power is produced when falling water is used to turn the turbine in an electric generator. No pollution is produced but building dams can damage habitats.
Alternative Energy Sources Wind power generates electricity by using windmills to turn the blades of a generator.
Alternative Energy Sources Nuclear energy is released when the nuclei of uranium atoms are split apart. Energy is used to produce steam to turn the blades of a generator. Does not produce air pollution but does produce radioactive wastes.
Alternative Energy Sources Solar energy is the leading alternative to fossil fuels because it is inexhaustible and produces no pollution. Very expensive. Photovoltaic cells are devices that convert light energy into electric energy.
A pollutant is any substance that contaminates the environment. Examples of air pollutants include smoke, ash, carbon monoxide, and carbon dioxide.
Greenhouse Effect The greenhouse effect is the natural trapping of the Sun’s heat by the Earth’s atmosphere. Gases that contribute to the greenhouse effect include water vapor, carbon dioxide, and methane.
Ozone Depletion The ozone layer of the atmosphere absorbs harmful ultraviolet (UV) radiation from the Sun. Ozone depletion is the thinning of the ozone layer. Allows more UV radiation to reach Earth and could cause an increase in skin cancer.