Across
- 1. effect Heat trapped by gases
- 5. Clearing of forests
- 8. Protection of natural resources
- 9. resource Limited, not replaced quickly
- 10. Plants make food
- 11. Living and nonliving system
- 12. cycle Movement of carbon atoms
- 15. Gradual ecosystem change
- 16. factor Nonliving environmental part
- 18. Total living matter
- 19. factor Living environmental part
- 20. Harmful environmental contamination
Down
- 2. resource Naturally replenished source
- 3. footprint Human resource use measure
- 4. cycle Circulation of nitrogen compounds
- 6. level Step in food chain
- 7. capacity Maximum sustainable population
- 13. Variety of living species
- 14. Meeting needs without harm
- 17. change Long-term weather shift