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Lecture 10

Lecture 10

Earth Sciences
Course Code
Christine Burton

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Glg205 t 10
Concern about environmental issues:
- Personal health
o E.g. lung cancer, eutrophication effects on fish
so what are we doing?
- Sometimes the action is fast and effective (e.g. CFCs)
- Sometimes the action is not so effective and slow (e.g. global warming)
Policy hurdles
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- Note when 03 formed in the atmosphere (about 2.5 million years ago)
o Slightly after atmosphere was oxygenated
- Note how 03 forms in the atmosphere
o Cyanobacteria took in CO2 and produced oxygen
o Sunlight hit the oxygen and broke it up into oxygen radicals
o They combine to form ozone
- Tropshpere ozone is a pollute
o Big component of smog
- Absorption of UV
o Warm air over cold air caps troposphere
Stratospheric ozone balance
- Ozone + UV ->
- Chlorine and nitric oxide combining with ozone to form oxygen
- Chlorine and nitric oxide work as a catalyst for ozone breakdown
Ozone depleting chemicals
- Sunlight breaks apart CFC and freeze the chlorine radical that catalyzes ozone breakdown
Arctic vs Antarctic
- Thinning was not evident in Arctic until recently
- Arctic not as cold as Antarctic
- Less ice crystals in the atmosphere where chlorine rest on to do their work
- Polar vortex t }o]]vZv]vÁu]v[v
o CFCs trapped in the cold air during the whole period
- Evidence of polar vortex
Montreal protocol
- Patents for CFC were running out
o Not making so much money by making CFC
- Scientists were certain what was making the ozone hole
- Industries wanted new patents to make more money
G7 economic summit in Paris
- Development of state of the environment indicators
Earth summit
- Stabilize greenhouse gas emissions
- Montreal protocol was replaced by new patents but now its hard to replace the fossil fuels we
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