2

• What is the primary function of greenhouse gases on Earth?

  They maintain temperatures on Earth high enough to support life
• What gases are included in greenhouse gases?

  • Water vapour
  • Carbon dioxide $(CO_2)$
  • Methane $(CH_4)$
• Describe the greenhouse gas effect

  1. Electromagnetic radiation at most wavelengths passes through the Earth’s atmosphere
  2. Earth absorbs radiation, warming up, essential for life
  3. Heat radiated from the Earth as infrared (IR) radiation
  4. IR radiation absorbed by greenhouse gases in the atmosphere
  5. Atmosphere warms up, leading to the greenhouse effect and global warming
• What human activities contribute to increased greenhouse gases in the atmosphere?

  • Driving $(CO_2)$
  • Consuming electricity $(CO_2)$
  • Raising livestock (cows – $CH_4)$
  • Decay of organic waste in landfill sites $(CH_4)$
• How does the absorption of IR radiation by greenhouse gases contribute to global warming?

  It traps heat in the atmosphere, increasing its overall temperature
• What are the major causes and effects of global climate change?

  Causes:

  • An increase in average global temperature

  
  

  Effects:

  • Extinction of species
  • Raising sea levels
  • Migration
  • Decrease in crop yields
• What is the carbon footprint?

  The total amount of $CO_2$ and other greenhouse gases emitted over the full life cycle of a product, service or event
• How can the carbon footprint be reduced?

  • Reduce emissions of $CO_2$ and methane
  • Use less electricity
  • Use alternative sources of electricity
  • Reduce travel and transportation
  • Plant more trees
• What are some limitations to reducing the carbon footprint?

  It can be more difficult, more expensive, and planting trees may take away land needed for growing crops