1. Why Antarctica 1. Strong winds blowing around the continent form what is known as the "polar vortex" - isolating the air over Antarctica from the rest of the world. 2. Special clouds form called Polar Stratospheric Clouds. Clouds don't normally form in the stratosphere and these turn out to have the effect of concentrating the pollutants that break down the ozone, so speeding the process up.

2. Ozone Depletion in the Stratosphere Stratospheric ozone layer Normal levels of ozone Reduced levels of ozone Dobson Units 100DU=1mm 1DU =.01mm

3. Ozone Hole? Normally 300 Dobson Units Equivalent to a layer of ozone 3mm thick or two pennies high One dime or 220 Dobson Units = thin Below 220 Dobson Units = depleted area or a “hole”

4. Ozone Depletion in Stratosphere CFCs / HCFC’s / Bromine / Halons

5. Recent Ozone Measurements

6. The Hole Sept.17 2009

7. Cancer

8. Ozone Depletion in the Stratosphere Montreal Protocol stipulated a reduction in CFCs - In 1987, the Montreal Protocol was signed by many nations who agreed to reduce their emissions of CFC's to a half (of the 1987 levels) by 2000. Smuggling CFCs remains a problem as well as old systems and disposal Full recovery of ozone levels is not likely before 2068 and regular improvement not likely until 2018. 30% reduction in 2007 but 2006 was the largest ever. Ozone depleting gases do appear to be trending downward but have long lifespans of 10’s to 100’s of years.

9. Acid Deposition AKA: Acid rain - snow, hail, sleet In US, damage from acid deposition is estimated at $10 billion

10. Acid Deposition Measuring Acidity

11. Acid Deposition

12. Power Plant

13. Acid Deposition How Acid Deposition Develops

14. Acid Deposition The Effects of Acid Deposition Acid Deposition and Forest Decline

15. Acid Deposition