Across
- 4. the disposal of waste material by burying it
- 5. transformation of fertile land into very dry desert
- 7. variety of different living organisms in an environment
- 10. salt levels
- 11. the four spheres
- 12. all the waters on the earth's surface
- 14. planting and taking care of trees and forests
Down
- 1. practice of farming and growing crops
- 2. removal of trees and other plants by either cutting or burning down
- 3. changes effecting the worlds weather
- 6. the watering of land to make it ready for agriculture
- 8. living organisms that interact with each other and the environment
- 9. gases surrounding the earth or another planet
- 13. any substance release into the environment that causes damage