Across
- 4. resource, natural resource that is being used up faster than it can be replaced by natural processes
- 7. mixture of gases that forms a layer around Earth
- 8. warming, scientific observation that Earth’s average temperature is increasing
- 9. resource, part of the environment that supplies a material that is useful or necessary for the survival of living things
- 11. precipitation, acidic rain or snow that forms when waste gases from automobiles and power plants combine with moisture in the air
- 12. manufacturing new products out of used products
- 13. something that has two different components performing essentially the same task
- 15. contamination of the environment with substances that are harmful to life
Down
- 1. smog, type of air pollution that is formed when sunlight reacts with waste gases from the burning of fossil fuels
- 2. energy, thermal energy from within Earth
- 3. resource, natural resource that can be replenished by natural processes at least as quickly as it is used
- 5. act of meeting human needs in ways that ensure future generations also will be able to meet their needs
- 6. resource, natural resource that will not run out, no matter how much of it people use
- 10. to appear or happen
- 14. layer, prevents most harmful ultraviolet (UV) radiation from reaching Earth