2.  Natural resources: substances that come from Earth EXAMPLES  Metals (ex. Gold & copper) for jewelry, coins, construction, etc  Nonmetals (ex. Halite & graphite) for food, pencil lead, jewelry, glass  Fossil Fuels (coal, petroleum) for heating, power plants, fuels, medicines, plastics

3.  Scarcity- As demand increases, supply can decrease, depending on the availability of the item  This can cause an increase in prices

4.  Recycling is a way to meet our needs and save resources while reducing the amount of trash that must be disposed of

5.  Renewable resources: can be replaced after they have been used  Examples: trees and, in general, freshwater (excludes desert areas)

6.  Nonrenewable resources: after they are used, they cannot be replaced for millions of years if at all  The resource may be used faster than it is replaced  Examples: gold and copper, iron, aluminum, and fossil fuels

7.  Fossil Fuels: coal, oil and natural gas, which were formed millions of years ago from the remains of ancient organisms  Scientists estimate that we will run out of coal within 200 years

8.  Alternative Energy Sources: other sources of energy to replace fossil fuels

9.  Solar energy:  Pros: a. plentiful b. provide heat, hot water and generate electricity  Cons: a. amount of sun varies with the time of day and seasons b. more expensive than fossil fuels

10.  Geothermal energy: comes from heat within Earth that can be used to generate electricity and produce heat and hot water  Problems: it’s only available in certain areas such as northern California and Iceland

11.  Wind Turbines: Uses energy from the wind to make electricity  Problem: only makes sense in areas where there are strong, steady winds.

12.  Hydroelectric power: Captures the energy from flowing water  Problems: dams may break or cause backup flooding

13.  Nuclear energy: generates electricity without causing air pollution  Cons: a. extremely dangerous b. need for long-term storage of radioactive wastes. c. Might be a target or radioactive resource for terrorists