Greenhouse Gases

• What is the importance of greenhouse gases?

  • Maintain temperatures on Earth high enough to support life
• Give three examples of greenhouse gases?

  • Carbon dioxide
  • Methane
  • Water vapour
• List two human activities that increase the levels of methane

  1. Burning fossil fuels
  2. Farming cattle / Agricultural Industry
• List two human activities that increase the levels of carbon dioxide.

  1. Burning fossil fuels
  2. Deforestation
• What will be the impact of climate change on weather patterns?

  1. An increase in global average temperatures
  2. More extreme weather
• Explain the problems with developing models on climate change (4)

  1. Too simple
  2. May be biased
  3. Too unreliable
  4. Speculations and opinions may be based on only parts of evidence
• Describe four potential effects of global climate change (4)

  1. Sea levels rising
  2. Extreme weather
  3. Glaciers + Ice caps melting
  4. More flooding / droughts
• Definition of carbon footprint:

  Total amount of carbon dioxide and other greenhouse gases emitted over the full cycle of a product, service or event.
• Environmental implications of global climate change?

  1. Increasing sea levels
  2. Glaciers and ice caps melt
  3. More extreme weather
  4. Flooding
• Carbon dioxide can be reduced in the following two ways :

  1. Reducing emissions of carbon dioxide
  2. Reducing emissions of methane
• Describe the greenhouse effect in terms of the interaction of short and long wavelength radiation with matter

  1. Electromagnetic radiation from the sun passes into the Earth's atmosphere.
  2. The earth absorbs EM radiation with SHORT wavelengths.
  3. Heat is radiated from the Earth as LONGER wavelength INFRARED radiation.
  4. Some of this infrared radiation is absorbed by greenhouse gases in the atmosphere.
  5. Thus, the atmosphere warms up due to global temperature increase
• Humans reduce global warming (6)

  • Instead of burning fossil fuels for electricity, generate electricity from renewable sources of energy like solar power.
  • Instead of deforestation, preventing deforestation by replanting trees.
  • Instead of intensive cattle farming, consuming less meat.
• Ways to reduce carbon footprint

  1. Carbon capture
  2. Energy conservation
  3. Renewable energy
  4. Replanting trees
• Why countries find it hard to invest in reducing carbon footprint?

  1. insufficient renewable energy resources
  2. too expensive
• Give one reason why it is difficult to produce models for future climate change.

  • Many alternative theories
  • Many different variables
  • Complex systems
• Describe how carbon dioxide helps to maintain temperatures on Earth. [3 marks]

  1. Carbon dioxide allows short wavelength radiation to pass through
  2. The atmosphere to the Earth's surface
  3. Carbon dioxide absorbs outgoing long wavelength radiation