2. Natural Resources How are resources used? What are the effects of using natural resources?

3. Fossil Fuels Fuels formed hundreds of millions of years ago from the remains of dead plants and animals They are a non- renewable resource Types of Fossil Fuels: coal, oil and natural gas

4. Natural Resources Renewable Resources Any resource that can be replaced by nature Examples: Soil, water, living things Non-Renewable Any resource that cannot be replaced by nature Examples: Fossil fuels and minerals

5. Uses of Fossil Fuels Coal is used to generate electricity Natural gas is used to heat homes Oil is used to make gasoline for transportation Industry/factories use lots of fossil fuels Main source of energy for electricity, homes, gasoline and factories.

6. Problems with Fossil Fuels In 100 years we will have used up all of our fossil fuel reserves Pollution is formed when fossil fuels are burned.

7. Alternative Sources Of Energy Solar energy, wind energy, and hydro- electric energy can be used instead of the fossil fuels. Also, geothermal, tidal, biomass, and hydrogen Alternative energy sources produce less pollution than fossil fuels

8. Solar Energy Solar energy used to heat buildings and to produce electricity. Photovoltaic cell- converts sunlight to electricity Problems w/ solar energy: –Sun doesn’t always shine -Solar panels are expensive

9. Other Alternative Sources Alternative energy sources have their downfalls Wind/water/sunlight are not predictable It is expensive to convert to a new energy source

10. The Earth’s Water Supply 97% of all water is in the oceans 3% freshwater is found in groundwater, lakes, and rivers Our water supply is being polluted very rapidly

11. Freshwater Supply Most of our freshwater comes from ground water New sources of fresh water include: desalination and melting glaciers

12. The Water Cycle Precipitation - water vapor falls from atmosphere (rain, hail, snow, sleet) Evaporation - water is pulled from the surface and changes into a gas Condensation - water vapor cools and condenses into clouds - precipitation Run-Off- water moves with gravity - downhill

13. Pollution When substances are released into the environment that change the environment for the worse 3 kinds of pollution - air, land, water * Human activity and factories are the main causes of pollution

14. Land Pollution Obtaining and using certain energy sources such as fossil fuels can pollute the land. Wastes from factories can pollute the land Nuclear power plants dispose radioactive wastes Garbage pollutes the land in landfills

15. Air Pollution Automobiles and factories are the biggest sources of air pollution Smog - thick, brown haze that forms when chemicals are in air Acid rain - chemicals in air cause rain to be more acidic

16. Water Pollution Causes of water pollution include: oils spills, factories dumping waste products into rivers and lakes, sewage being dumped and agricultural run-off

17. Reducing Pollution Everyone should conserve energy when possible Scientists need to find cleaner ways to use energy Everyone needs to make sure that wastes are disposed of in the safest possible way RECYCLE