Composition of the atmosphere

• How much nitrogen is in the atmosphere today?

  80 %
• How much oxygen is in the atmosphere today?

  20 %
• The earth is 4.6 billion years old
• Volcanic activity released lots of carbon dioxide , sulfur and nitrogen andwater vapour
• The planet cooled below 100 degrees and rainfall occurred for thousands of years forming oceans and these oceans sequestered the carbon dioxide
• Where did oxygen come from?

  Photosynthesis in plants and algae 2.7 billion years ago
• Carbon dioxide also went in through the stomata in photosynthesis
• Carbon dioxide went into sedimentary rocks
• Combustion of fossil fuels (coal, oil and gas) led to to increase of greenhouse gases - mostly CO2

  This happened because of population increase and requirement of energy
• Deforestation also led to increase of CO2

  This was because of population increase, increased resource requirement and increased space needed for agriculture and buildings
• Raising more cattle led to more methane produced ( as they let it out as a gas)

  This was because of population increase requiring more food
• Decomposition of waste has also led to increase of methane as microbes begin to decompose the waste producing methane

  This is because of population increase
• What are the three main greenhouse gases?

  Carbon dioxide , methane and water vapour
• What is the greenhouse effect?

  High energy is released from the sun in short wave radiation with a high frequency this absorbs into the earth yet some reflects back into space as long wave radiation with a low frequency and low energy.
• Sometimes the waves are re- radiated back into earth because of the green house gases trapping the energy
• What are the effects of climate change?

  Water stress- reduction of fresh water as ice caps melt (40% of the worlds population rely on ice caps for fresh water)

  Distribution of wildlife species - migration patterns of birds will change

  Temperature stress - too hot for people to live in areas around the world

  Changes in the food producing capacity - increased evaporation of water from the soil
• What is a carbon footprint?

  Total amount of carbon dioxide an other gases emitted over the full life cycle of a product, service or event
• How can we reduce carbon footprint?

  Alternative energy - solar panels (reduce fossil fuel consumption)

  Energy conservation and efficiency in homes - double glazing and wall/ attic insulation

  Energy efficient cars
• What is carbon capture?

  Chimneys get capped at factories and the carbon dioxide is piped underground
• What is carbon offsetting?

  Spending money on carbon removal schemes to balance carbon emissions
• What is carbon neutrality?

  A process that absorbs the same volume of carbon dioxide as it releases
• Carbon dioxide

  Produced by complete combustion

  Leads to global warming
• Carbon monoxide

  Produced by incomplete combustion

  Reduced by catalytic converter

  It is toxic
• Solid carbon particulates

  Produced by incomplete combustion

  Reduced by filters

  Leads to global dimming
• Sulphur dioxide

  Produced by impurities in the fuel

  Reduced by catalytic converter

  Leads to acid rain
• Oxides of nitrogen

  Nitrogen in the air reacts with oxygen in the air because of high temperature (usually in car engine)

  Reduced by coolants within the engine

  Leads to acid rain