Across
- 2. made dirty or unsafe by harmful substances
- 3. natural homes where animals and plants live
- 6. warming the Earth getting hotter over time
- 8. gases gases that trap heat around the Earth
- 11. light harmful invisible light from the sun
- 14. when roads are full of traffic and cars move slowly
- 15. a very dry area with little rain and few plants
- 17. the layer of air around the Earth
- 18. substances made by mixing different materials
Down
- 1. land with farms, fields, and nature outside cities
- 4. layer a protective layer of gas high in the sky
- 5. when water covers land that is usually dry
- 7. fumes dirty gases that come out of cars and vehicles
- 9. when a type of animal or plant no longer exists
- 10. thick dirty air you can see, usually brown or gray
- 12. rain rain that contains harmful chemicals
- 13. something that makes air, water, or land dirty and unsafe
- 16. thick forests with many trees and heavy rainfall
- 18. man-made chemicals that damage the ozone layer
- 19. at risk of disappearing forever