Lecture #24- Atmosphere and the Environment P 440-442

1. Greenhouse Effect
   1. Gasses in the atmosphere hold in infrared radiation (HEAT) from the sun.
   2. CO2 , Ozone, methane, water, CFC’s
   3. Result is a relatively warm habitable planet. (greenhouse effect)
2. Where does the CO2 come from?
   1. Photosynthesis (remember 6CO2 + 6H20 + light => sugar + O2)
   2. Green plants are a Sink of CO2 C. Balanced with Photosynthesis is Respiration. 02 + Sugar => CO2 + H2O + Energy.
   3. What’s the problem?
   4. CO2 levels are increasing and so is the mean global temperature.
   5. Where is this increased CO2 coming from?
      1. Burning of Fossil Fuels
      2. Deforestation-burning of trees in rain forest (adds 30-35% of CO2)
3. Potential Consequences
   1. Increase in earth’s mean temperature is already happening
   2. If it happens too fast ecosystems can’t adapt
   3. Effects food producing areas the most
   4. Rise in the ocean levels due to ice cap melting
4. The Ozone problem
   1. What is Ozone: O 3
   2. What does it do.
      1. An air pollutant down low-photochemical smog
      2. Protects the earth from UV radiation up high
   3. Some evidence that it is decreasing
   4. Chlorofluorocarbons
      1. “useful” molecules, now destroying the ozone layer
      2. Results of depletion of ozone layer
      3. Human health problems, and crop damage, ocean productivity
   5. Solutions-some progress is actually being made.