Across
- 3. process of recycled soil, water, living things and the atmosphere
- 5. thick subsurface layer of soil that remains below freezing point throughout the year
- 6. area of forests or trees
- 7. capable of being renewed
- 8. condition in the atmosphere
- 10. warming of the Earth caused by greenhouse gases
- 12. electromagnetic waves or high-energy particles which cause ionization
- 13. main constituent of natural gas
- 15. when organisms use sunlight to synthesize nutrients
- 16. contain carbon of plants and animals that died
- 18. water which collects as droplets on cold surface when humid air is in contact
- 20. extreme of the Southern Oscillation that causes drought in parts of Australia
- 21. interacting organisms and their physical environment
Down
- 1. living things on Earth
- 2. water on the earths surface
- 3. weather condition
- 4. used in photosynthesis, gas
- 9. for the 'global conveyor belt'
- 11. land masses on Earth
- 14. symbol 'N'
- 17. radiation that cannot pass through glass
- 19. gas surrounding the Earth