Twenty Questions and Answers About the Ozone Layer: 2014 Update

1. Ozone in our atmosphere

1. What is ozone and where is it in the atmosphere?
2. How is ozone formed in the atmosphere?
3. Why do we care about atmospheric ozone?
4. How is total ozone uniform over the globe?
5. How is ozone measured in the atmosphere?
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2. The ozone depletion process

6. How do emissions of halogen source gases lead to stratospheric ozone depletion?
7. What emissions from human activities lead to ozone depletion?
8. What are the reactive halogen gases that destroy stratospheric ozone?
9. What are the chlorine and bromine reactions that destroy stratospheric ozone?
10. Why has an "ozone hole" appeared over Antarctica when ozone-depleting substances
     are present throughout the stratosphere?
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3. Stratospheric ozone depletion

11. How severe is the depletion of the Antarctic ozone layer?
12. Is there depletion of the Arctic ozone layer?
13. How large is the depletion of the global ozone layer?
14. Do changes in the Sun and volcanic eruptions affect the ozone layer?
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4. Controlling ozone-depleting substances

15. Are there controls on the production of ozone-depleting substances?
16. Has the Montreal Protocol been successful in reducing ozone-depleting substances
     in the atmosphere?
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5. Implications of ozone depletion and the Montreal Protocol

17. Does depletion of the ozone layer increase ground-level ultraviolet radiation?
18. Is depletion of the ozone layer the principal cause of climate change?
19. Have reductions of ozone-depleting substances under the Montreal Protocol
     also protected Earth's climate?
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6. Stratospheric ozone in the future

20. How is ozone expected to change in the coming decades?
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Additional Topics

• Global Ozone Network - end of Question 5
• Understanding Stratospheric Ozone Depletion - end of Question 6
• The Discovery of the Antarctic Ozone Hole - end of Question 10
• The 2002 Antarctic Ozone Hole - end of Question 11
• Initial Signs of Ozone Recovery - end of Question 13
• The Antarctic Ozone Hole and Southern Hemisphere Surface Climate - end of Question 18