Objective: Section 18-8 to 18-9  Describe stratospheric ozone depletion and solutions to protect the ozone layer.

Ozone Schmozone  What is ozone?  Do I really need to care?  What is ozone?  Do I really need to care?

Ozone Formation in the Stratosphere Importance  Absorbs UV  Terrestrial life  Absorbs UV  Terrestrial life

Ozone Depletion in the Stratosphere Fig p. 473 Depletion  O 3 + CFCs → O 2 + CFCs + O

CFCs destroying ozone animation.

Ozone Depleting Chemicals  Chlorofluorocarbons (CFCs)  Halons  Methyl bromide  Carbon tetrachloride  Methyl chloroform  Hydrogen chloride

Seasonal Thinning at the Poles  Ozone thinning (hole)  Polar vortex Fig p. 475

Reasons for Concern  Increased incidence and severity of sunburn  Increase in eye cataracts  Increased incidence of skin cancer  Immune system suppression  Increase in acid deposition  Lower crop yields and decline in productivity

Solutions: Protecting the Ozone Layer  CFC substitutes  Technofixes  Montreal Protocol Fig p. 479

Solutions: Protecting Yourself  Common sense

Generalization  What chemicals play a major role in ozone thinning?  Summarize the destruction of stratospheric ozone.  What is the best solution for preventing ozone thinning?  What chemicals play a major role in ozone thinning?  Summarize the destruction of stratospheric ozone.  What is the best solution for preventing ozone thinning?

Objective: Section 18-8 to 18-9  Describe stratospheric ozone depletion and solutions to protect the ozone layer.