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Ozone Layer Depletion
Ozone Layer Facts...Ozone Layer Depletion •Lower stratosphere (above troposphere) •Allows life to exist on Earth •Serves a...
A Closer Look at the causes of             depletionDepletion Caused By: • CFC’s, Halons, Bromine • CFC’s: Tom Midgely, GM...
How was the damage             discovered?•Sherwood Rowland and Mario  Molina in the 1970’s•Investigated years of atmosphe...
Some AtmosphericFormation
of
Ozone            Chemistry...O2
+
UV
light
‐>
2
OO
+
O2
+
M
‐>
O3
+
M
(where
M
indicates
cons...
Polar Vortex and The                Cause of Antarctic                       Hole               • 1984 Satellite data: 40-...
Montreal Protocol of 1987• Identified CFC’s for elimination first• Less harmful HCFC’s and HFC’s later• Bromine, Halons, Fum...
The Larger Questions...• Why was the Montreal Protocol so  successful?• Why has the Kyoto Protocol been less  successful?•...
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Ozone Layer Depletion

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Ozone Layer Depletion

  1. 1. Ozone Layer Depletion
  2. 2. Ozone Layer Facts...Ozone Layer Depletion •Lower stratosphere (above troposphere) •Allows life to exist on Earth •Serves as UV filter: 95% of harmful rays •Without it: increased risk of cataracts, sunburn, skin cancer
  3. 3. A Closer Look at the causes of depletionDepletion Caused By: • CFC’s, Halons, Bromine • CFC’s: Tom Midgely, GM chemist • Uses: refrigerants, propellants, cleaners, fumigants, blowing agents for Styrofoam • Inactive, easy to make, $28 billion industry: duPont lead producer at the time
  4. 4. How was the damage discovered?•Sherwood Rowland and Mario Molina in the 1970’s•Investigated years of atmospheric data rejected by computers•Shocked scientific community & the public•Powerful lobby against them
  5. 5. Some AtmosphericFormation
of
Ozone Chemistry...O2
+
UV
light
‐>
2
OO
+
O2
+
M
‐>
O3
+
M
(where
M
indicates
conservation
of
energy
and
momentum)Anthropogenic
Destruction
of
Ozone
by
CFC’sCl
+
O3
‐>
ClO
+
O2ClO
+
O
‐>
Cl
+
O2
  6. 6. Polar Vortex and The Cause of Antarctic Hole • 1984 Satellite data: 40-50% of Antarctic ozone lost during spring and summer. • Polar vortex. Dark, frigid winter months: strong winds create swirling masses of air in stratosphere. • Winds create suspended microscopic ice crystals that serve as templates for CFC’s to catalyze breakdown of ozone.Polar Vortex • Similar, but less dramatic in Arctic.
  7. 7. Montreal Protocol of 1987• Identified CFC’s for elimination first• Less harmful HCFC’s and HFC’s later• Bromine, Halons, Fumigants• Multinational Fund• Significant repair of ozone layer: 2050
  8. 8. The Larger Questions...• Why was the Montreal Protocol so successful?• Why has the Kyoto Protocol been less successful?• Where is the line dividing economic prosperity and the environment?

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