Chemistry of the atmosphere

• What happened during the first stage of the atmosphere?

  • mostly carbon dioxide and no oxygen

  • volcanic activity released nitrogen as well as water vapour, methane and ammonia
• What happened during the second stage of the atmospshere?

  • water vapour condensed forming oceans

  • carbon dioxide dissolved into ocean, went through series of reactions to form carbonate precipitates that formed sediment on the seabed

  • green plants and algae evolved and absorbed carbon dioxide for photosynthesis

  • marine animals formed - shells and skeletons contained carbonates from oceans

  • organisms took in carbon - locked up in rocks and fossil fuels when organisms died
• What happened during the third stage of the atmosphere?

  • green plants and algae produced oxygen as a product of photosynthesis

  • oxygen levels rose meaning more complex life (animals) could evolve

  • atmosphere composition

  -> 80% nitrogen

  -> 20% oxygen

  -> 1% carbon dioxde, noble gases and water vapour
• How do the greenhouse gases cause increase in temperature?

  • do not absorb short wavelength radiation from sun

  • absorb long wavelength radiation that is reflected from earth
• What concequences does climate change have?

  • ice caps melting - causing rise in sea levels, increased flooding in coastal areas and coastal erosion

  • changes in rainfall patterns - amount, time and distribution

  • frequency and severity of storms may increase
• What is a carbon footprint?

  measurement of carbon dioxide and other greenhouses gases released over a full life cycle
• What are ways of reducing carbon footprint?

  • renewable energy sources or nuclear energy instead of fossil fuels

  • government tax companies based of amount of greenhouse gases they emit

  • government cap emissions

  • caputure carbon dioxide produced by burning fossil fuels before released into atmosphere
• What problems do particulates in the air cause?

  • inhaled, gets stuck causing damage and respiratory probelms

  • reflects sunlight back into space causing global dimming
• How does sulfur dioxide and nitrogen oxides cause danger?

  • sulfur dioxide is released during combustion of fossil fuels which contain sulfur impurities and become oxidised

  • nitrogen oxides are created when nitrogen and oxygen react by heating (can happen in engines of cars)

  • gases mic with clouds forming dilute sulfuric or nitric acid - acid rain

  • this kills plants and damages buildings

  • causes respiratory problems when inhaled