Across
- 3. rock/stone
- 7. trashcan
- 8. river
- 9. stars
- 11. endangered species
- 14. hiking
- 15. picnic
- 16. tropical forest
- 17. mountains
- 18. to decrease
Down
- 1. to waste
- 2. overpopulation
- 4. solar energy
- 5. drought
- 6. Earth
- 10. to improve
- 12. deforestation
- 13. to increase