Across
- 3. the gradual increase in Earth's temperature
- 9. the rock that makes up Earth's surface
- 12. the water and human wastes that wash down drains
- 13. any substance that causes pollution
- 16. a thick, brownish haze formed when certain gasses in the air react with sunlight
- 17. the wastes produced in homes, businesses, schools and the community
- 19. any material that is harmful to humans or the environment that is not properly disposed of
- 22. airborne pollutants
- 24. chemicals that kill crop-destroying organisms
- 25. a layer of nutrients, air, rock fragments and water
- 26. human made gasses that contain chlorine and fluorine
- 31. a period where less rain than normal falls in an area
- 32. the process by which water, wind or ice moves particles of rock
- 33. the rocky layer below topsoil
Down
- 1. energy-rich substances formed from the remains of organisms
- 2. gasses that absorb heat leaving Earth's surface
- 4. water stored in soil and rock
- 5. the process of restoring an area's productivity
- 6. the advance of desert-like conditions in areas that were once fertile
- 7. the process of reusing old products to make new ones
- 8. a polluted liquid created from rainwater and chemicals in a dump
- 10. holds municipal waste, construction debris, and other waste
- 11. when soil becomes less fertile
- 14. nutrients to help crops grow better
- 15. warm air prevents smog from rising during this
- 18. a radioactive, colorless, odorless gas
- 20. the burning of solid waste
- 21. the top layer of dead leaves and grass
- 23. particles of rock and sand
- 27. a layer of the upper atmosphere about 15 to 30 km above the Earth's surface
- 28. a form of oxygen found in smog
- 29. precipitation that is more acidic than normal
- 30. materials that can be broken down by bacteria and other decomposers