Untitled

• The four spheres


  • Biosphere
  • Hydrosphere
  • Atmosphere
  • Lithosphere
• Biosphere


  The region at the surface of the earth where all life exists
• Hydrosphere


  The region of water on the earth (97% fresh water, 3% mostly frozen fresh water, 1% liquid fresh below ground)

  
• Atmosphere


  Consists of all the gases that surround the world, (78% nitrogen, 21% oxygen + 0.004% carbon dioxide)
• Lithosphere


  The earth's solid crust and the cool part of the mantle immediately below the crust; rock, mineral, soil
• The water cycle


  1. Transpiration

  2. Evaporation

  3. Condensation

  4. Precipitation

  5. Runoff

  6. Sublimation

  7. Deposition

  8. Infiltration

  9. Percolation
• Photosynthesis: CO2 is taken into plants and changed into plant food. Oxygen is given off.
• Photosynthesis


  6CO2 + 6H2O = C6H12O6 + 6O2
• The food chain: plant food stored with carbon is passed from animal to animal
• Respiration


  • Animals take in oxygen and exhale CO2
  • C6H12O6 + 6O2 = 6H2O + 6CO2 + energy
• Decomposition: when plants and animals die their bodies decay and carbon dioxide is released into atmosphere. (burning of fossil fuels)
• Recycling of materials: ensures that essential nutrients are continuously reused, maintaining soil fertility and supporting plant growth.
• The Nitrogen Cycle


  1. Nitrogen fixation

  2. Nitrification

  3. Denitrification
• Producers


  Synthesise nitrogen-containing organic compounds
• Consumers


  Get nitrogen compounds from the plants and animals they eat
• Plants mainly get nitrogen from the soil as nitrate ions (NO3-), created by bacteria and fungi through nitrogen fixation, ammonification, and nitrification processes.
• Nitrogen-fixing microorganisms capture atmospheric nitrogen by converting it into ammonia which can be taken up via plant roots.
• Weather


  Short term, limited area, change rapidly, hard to predict
• Climate


  The average of many years of weather observation
• Greenhouse gases


  • Water vapour
  • Carbon dioxide (risen 30% since industrial revolution)
  • Methane (cows, coal mining, landfills)
  • Nitrous oxide (produced by cars)
• If we had 0 greenhouse gases in the atmosphere, it would be -18 degrees
• Greenhouse gas content is being altered by human activity
• Greenhouse effect


  Traps the sun's energy at the earth's surface (essential for life on earth)
• Enhanced greenhouse effect


  Traps too much of the sun's energy (global warming) caused by human activity
• Climate change


  Refers to the increase of the average surface temperature of the earth caused by the greenhouse effect
• How to prevent further climate change

  • Conserve hot water
  • Conserve in the car
  • Conserve electricity
  • Reduce waste
• Global warming


  Contributes to climate change
• Weather models


  Make predictions about specific areas and short time spans
• Climate models


  Are broader and analyse long time spans

  
• Ocean currents


  • Major surface currents (caused by winds)
  • Deep ocean currents (carry very cold water)
  • Thermohaline circulation (movement of water between surface and deep ocean currents)
• Southern oscillation


  Sequence of changes to the way the atmosphere and water circulate across the pacific ocean
• El nino


  Always result in drought
• La nina


  Increased rainfall in NA
• Glaciers are large masses of ice that form over many years from snow accumulation. When glaciers melt or retreat faster than they accumulate snow, it indicates warming temperatures, providing clear evidence of climate change.
• Ice cores are like frozen time capsules drilled from ice sheets and glaciers. By studying the layers of ice, scientists can see how temperatures and atmospheric conditions have changed over thousands of years, giving clear evidence of climate change.
• Ozone layer


  A protective layer of ozone gas in the earth's atmosphere, 10-50 Km above the earth's surface, acting as a shield and absorbing most of the sun's UV
• The ozone layer blocks out 95% of the UV rays entering our atmosphere
• It is important we maintain a high biodiversity on earth because it provides medicines, clean water, food, health marines and economic aesthetic.
• The impact of climate on ecosystems includes mass extinction events, periods of increasing warmth, and species moving to the poles.
• Monoculture


  The cultivation of a single crop in a given area. Less species diversity, less genetic biodiversity, lack of ability for crops to survive pests and natural disaster.