Atmosphere

• Phase 1 - 1st billion years

  Earths surface covered in volcanoes -> erupted and released lots of gas to form earths early atmosphere

  Probably mainly carbon dioxide with virtually no oxygen (similar to Mars and Venus now)

  Nitrogen was also released

  water vapour, methane and ammonia will have been released in small amounts
• Phase 2

  Water vapour condensed to form oceans, so lots of the carbon dioxide dissolved -> it went through reactions to form sediment on the ocean floors

  green plants and algae evolved: they absorbed carbon dioxide for photosynthesis

  marine animals shells and skeletons contains carbonates from the ocean floor

  some of the carbon taken in became locked in rocks and fossil fuels
• trapping carbon in rocks and fossil fuels:

  • plants, plankton and marine life die, they are buried in layers if sediment on the sea bed, trapping carbon
  • crude oil and natural gas are formed when this happens to plankton
  • coal is made from thick plant deposits
• Phase 3 - producing oxygen


  green plants and algae produce oxygen through photosynthesis

  2.7 billion years ago - algae evolved

  as oxygen built up, complex life developed
• 200 million years ago, the configuration in the atmosphere reached that of today

  • 80% nitrogen} aproxx
  • 20% oxygen } aproxx
  • small amounts of carbon dioxide, noble gases and water vapour
• climate change consequences

  melting polar icecaps - causes a rise in ocean levels, increased flooding and coastal erosion

  changes in rainfall patterns cause the amount of rainfall regions get

  ^ this and temperature changes affect food production

  frequency and severity of storms
• carbon footprint

  amount of carbon dioxide and greenhouse gases released over a full life cycle of something like a service, event or product

  eg the Olympics, the school bus
• carbon footprint

  • comes from many different factors like using, making, sourcing parts which makes them near impossible to measure
• reducing carbon footprint 


  renewable energy sources

  more efficient processes to conserve energy and reduce waste

  governments can tax companies and individuals based on greenhouse gas usage

  governments can cap greenhouse gases emissions on companies