B4 2020 Bohn

123456789101112131415161718
Across
  1. 3. makes up 78% of the atmosphere
  2. 7. reflects and modifies radio waves
  3. 11. harmful materials being released
  4. 12. an increase of this as a result of the greenhouse effect
  5. 14. auroras
  6. 15. makes up about 1% of the atmosphere
  7. 17. third layer of the atmosphere
  8. 18. makes up 21% of the atmosphere
Down
  1. 1. more people on earth
  2. 2. contains the ozone layer
  3. 4. primary greenhouse gas
  4. 5. tearing down trees/wildlife
  5. 6. the layer we live in
  6. 8. can be helpful or harmful
  7. 9. lowest density
  8. 10. often comes from cows
  9. 13. what some heat does back into space
  10. 16. heating of the earth