Across
- 2. One of the three types of fossil fuels
- 3. Forms 78% of the atmosphere
- 4. One of the main components of fossil fuel
- 6. One of the layers of the atmosphere
- 8. Layer that protects us from harmful ultraviolet lights
- 11. Alternative type for green energy
- 12. One of the reasons that fossil fuels are used
Down
- 1. Consequence of toxic chemicals and particles entering the atmosphere
- 4. One of the human causes of air pollution
- 5. Thin layer of gasses that surrounds the Earth
- 7. Can reduce pollution
- 9. One of the natural causes of air pollution
- 10. Type of greenhouse gas