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Questions | Answers

1. Global warming/climate change is an upward trend in global temperatures largely due to human activities.

2. 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.

3. The most likely cause of global warming/climate change 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.

4. 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.

5. The effects of global warming/climate change 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.