Greenhouse gases and Climate Changes

• Greenhouse gases


  • Carbon dioxide
  • Methane
  • Water vapour
• How greenhouse gases work

  1. The sun gives out short wavelength radiation

  2. This radiation is reflected back by the Earth as long wavelength radiation

  3. This is thermal (heat) radiation

  4. It's then absorbed by greenhouse gases

  5. Greenhouse gases then give out this radiation in all directions

  6. Some radiation heads back toward the Earth and warms up the surface
• Greenhouse gases keep the Earth warm enough to support life
• Human activities that increase greenhouse gases


  • Deforestation
  • Burning fossil fuels
  • Agriculture
  • Creating waste
• Recently, the average temperature of the Earth's surface has been going up
• Most scientists think this has been caused by the extra carbon dioxide from human activity
• They believe this will lead to climate change
• Evidence for this has been peer-reviewed, which means the information is reliable
• The Earth's climate is very complex, so it's very hard to make a model that isn't oversimplified
• This has led to people forming their own theories and opinions, particularly in the media
• These stories aren't based on good evidence - they may be biased or only give some of the information
• If something's biased, it favours one point of view in a way that's not backed up by facts
• Dangerous consequences of climate change


  • Higher global temperature could cause ice in the Arctic and Antarctic to melt, causing sea levels to rise, which could lead to more flooding
  • Changes in rainfall may cause some regions to get too much or too little water
  • Storms may become more frequent and severe
  • Changes in temperature and rainfall may affect the production of food in certain places