Across
- 2. it prevents harmful ultraviolet light from the sun from reaching the earth
- 7. the cutting down of trees in a large area
- 8. a mountain with a large circular hole at the top through which lava gases, steam and dust are or have been forced out
- 9. the process by which land changes into desert
Down
- 1. poisonous gas
- 3. harmful chemicals in the air
- 4. number and variety of plant and animak species in particular area
- 5. damage caused to water, air or soil by harmful substances or waste
- 6. to collect and treat rubbish to produce useful materials which can be used again
- 10. general weather conditions usually found in a prticular place