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AIR POLLUTION AND OZONE LOSS - A Chapter 19
AIR POLLUTION AND OZONE DEPLETION CHAPTER 19
This unit is entirely based on Chapter 19 of your textbook. It covers all of Unit 6 and part of Unit 9 from the AP curriculum.
• 6.1 – Introduction to Air Pollution
• 6.2 – Photochemical Smog
• 6.3 – Thermal Inversion
• 6.4 – Atmospheric CO2 and Particulates
• 6.5 – Indoor Air Pollutants
• 6.6 – Reduction of Air Pollutants
• 6.7 – Acid Rain
• 6.8 – Noise Pollution
• 9.1 – Stratospheric Ozone Depletion
• 9.2 – Reducing Ozone Depletion
9.1 – STRATOSPHERIC OZONE
UNEP/WMO, 2006: Fig. Q1-2
OZONE IN THE ATMOSPHERE
• Stratosphere – Good Ozone – Blocks UV radiation – Hole caused by depletion
due to CFC’s • Troposphere – Bad Ozone
– Pollution • Photochemical smog • Eye irritant
UNEP/WMO, 2006: Fig. Q2-1
HOW IS OZONE FORMED? • Ozone forms a
layer in the stratosphere, thinnest in the tropics (around the equator) and denser towards the poles.
GOOD OZONE
6
NATURAL VARIATIONS OF TOTAL OZONE
• Fall • Highest at mid- and high
latitudes
• Winter and spring • Lowest in polar regions
(due to movement of chlorine and bromine)
• Year round • Low in the tropics (less
dense)
SEASONAL VARIATION
• Ozone thinning (hole) occurs each winter in the Arctic and Antarctica
• Polar vortex traps CFCs over polar regions
WHY WORRY ABOUT OZONE HOLES?
• Increase health issues • Sunburns • Skin cancer • Cataracts • Immune system
suppression
• Environmental Issues • Lower productivity
OZONE DEPLETION CULPRITS
• CFCs • Other culprits
• Halons and HBFCs from fire extinguishers
• Methyl bromide, a fumigant
• Hydrogen chloride from space shuttles
OZO
NE
DEP
LETI
ON
One CFC molecule removes 100,000 Ozone molecules
9.2 – REDUCING OZONE DEPLETION
13
SOLUTION: MONTREAL PROTOCOL 1989
• An international treaty designed to protect the ozone layer – phasing out production of number
of substances believed to be responsible for ozone depletion
UNEP/WMO, 2006: Fig. Q15-1
OZONE AND GLOBAL WARMING
Ozone Depletion
• Loss of O3 in stratosphere
• Increased UV radiation to Earth’s surface
• CFCs, HBFCs, Bromines
• Decreased productivity due to ‘frying’ of photosystems
• Increased skin cancer and cataracts
• SUCCESS – Montreal Protocol
Global warming • Accumulation of GHGs in troposphere
• Increased trapping of IR radiation in Earth’s troposphere
• CO2, CH4, N2O, H2O, CFCs, O3
• Decreased productivity due to shifts in temperature and precipitation
• Climate shifts
• Increased tropical diseases
• No successful policy to date – Kyoto Protocol
UNEP/WMO, 2006: Fig. Q18-1
OZONE ANIMATIONS
• What is ozone? • How is ozone destroyed?