Across
- 4. naturally replaced, like sun or wind
- 7. long time without rain
- 9. element found in CO₂
- 10. sources of energy like coal or gas
- 11. general weather of an area
- 13. ancient remains used as fuel
- 15. large body of salt water
- 16. frozen water
- 18. increase or go up
- 19. increase in temperature
Down
- 1. worldwide
- 2. turning from solid to liquid
- 3. height or position
- 5. dirty or harmful substances
- 6. overflow of water
- 8. poisonous or harmful
- 9. becoming different over time
- 11. polar ice sheets
- 12. release of gas or smoke
- 14. unwanted or leftover material
- 17. power used for work or heat