1. Ozone is beneficial in the stratosphere as the "ozone layer". The ozone layer reduces the amount of ultraviolet light reaching Earth's surface which reduces skin cancer, eye cataracts, etc. Ozone is bad in the troposphere where it damages respiratory systems, irritates eyes, damages plants, damages building materials such as rubber, paint, and plastics.

2. Ozone depletion occurs in the stratosphere everywhere over Earth. The greatest depletion occurs at the poles and the least at the equator, but ozone depletion occurs over all of Earth's surface.

3. Ozone depletion occurs when CFCs and other chlorine and bromine containing compounds reach the stratosphere and convert ozone to oxygen. In the case of CFCs, the UV light knocks off a chlorine atom from the CFC and the chlorine atom pulls the third oxygen atom off of ozone, converting the ozone to oxygen gas and producing chlorine monoxide.

4. The effects of ozone depletion include skin cancer, eye cataracts, immunosuppression, increased photochemical smog, decreased crop yield, property damage, and other environmental effects.

5. First the Montreal Protocol (an international treaty) called for CFC use to be cut in half by 2000, then the U.S. banned CFC use by 1996.

6. Normal rain has a pH of 5.6.

7. For rain to be considered acid rain, it has to have a pH below 5.6.

8. Buffering Capacity is the ability of a substrate to neutralize an acid or base.

9. Mostly sulfur dioxide and nitrogen oxides from fossil fuel burning.

10. Increased susceptibility to death from frost, pests, and disease due to reduced nutrient and water uptake due to:
a. Direct damage to leaves and bark
b. Soil acidification leaching soil nutrients
c. Soil acidification killing certain essential soil microorganisms
d. Soil acidification releasing toxic metals which damage fine roots

11. Other effects of acid deposition include "lake death" and property damage

12. Global warming is an upward trend in global temperatures largely due to human activities.

13. Major greenhouse gases

• Carbon Dioxide: mostly from burning fossil fuels and deforestation
• Methane: agriculture (rice paddies and livestock), pipeline leaks, landfills; also anaerobic decay in permafrost (positive feedback loop), bogs, termites, etc.
• Nitrous Oxide: mostly from agriculture (the application of fertilizers, feedlots) and auto emissions.
• Fluorinated Gases: hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are synthetic chemicals used in industry (these are alternatives to CFCs, etc. that have been banned).
• Water Vapor is another very important greenhouse gas.
  

14. The most likely cause of global warming is increases in greenhouse gas concentrations in the atmosphere largely due to human pollution, especially fossil fuel burning but also deforestation, livestock, rice paddies, pipeline leaks, and landfills.

15. Negative Feedback Loops

1. Increasing CO2 will increase oceanic algae will increase absorption of CO2 out of atmosphere, thus decreasing CO2.
2. Increase in CO2 will stimulate plant growth thus absorption of CO2 out of the atmosphere, thus decreasing CO2.
3. Increase warming will result in more evaporation, more clouds, more reflectance, less warming.

Positive Feedback Loops

1. Increase warming will result in more evaporation, more water vapor in air and greater greenhouse effect from water vapor, thus more heating.
2. Increase warming will melt permafrost, releasing methane, thus increase warming.
3. Increase warming will decrease snowpack and ice decreases reflectance, so increase warming.
4. Warmer temperatures cause greater use of air conditioners thus increasing fossil fuel burning and greenhouse gas emissions, thus warmer temperatures.

16. The effects of global warming include:

• Agricultural Effects due to changing temperature and precipitation patterns.
• Loss of Biological Diversity due to climate change
• Sea Level Rise thus coastal flooding due to thermal expansion of oceans and melting of ice caps.
• Weather hazards may increase in intensity or abundance: e.g. hurricanes
• Health Effects
  

17. Kyoto Protocol, but U.S. is not ratifying. Efforts at the state level are being done.