Across
- 4. Land masses on the Earth
- 5. Time between glaciations
- 8. Continuous movement of water due to natural processes e.g. wind
- 9. A change in the Earth's climate
- 10. All the liquid of water on the Earth's surface
- 14. The state of the atmosphere
- 16. Colourless and odourless gas, produced by burning carbon or organic substances
- 17. Prehistoric organisms remain
- 18. The main basic of natural gas
- 19. Be maintained at a certain rate or level
Down
- 1. All living things
- 2. Life in the world or habitat or ecosystem
- 3. A spiral of ocean currents in the major oceans
- 6. The cycle between living and non-living environments
- 7. Layers of gases around the planet
- 11. Layers of soil and rock that remains frozen throughout the year
- 12. A community of living and interacting organisms and their environment
- 13. Increase of temperature in the atmosphere
- 15. Natural fuel
- 16. Averages of weather conditions on a long term basis