Earth And Space sciences

• Lithosphere


  The rocky upper layer of the Earth that includes the crust and the upper mantle.
• Hydrosphere


  Makes up all matter on earth, including in gas and solid forms.

  Water is stored as ice in the cryosphere.
• Atmosphere


  A layer of gas that surrounds the Earth, mainly consisting of nitrogen and oxygen, with small amounts of other gases.

  Divided into 5 layers:

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere
• Biosphere


  Includes all living organisms and relies on all the other spheres for water, air and nutrients.
• The Carbon Cycle


  The carbon cycle reveals how carbon moves between various locations on Earth.

  
• The Carbon Cycle 


  Steps:

  1. C mainly exists as CO2 in the atmosphere. If there's too much CO2 in the atmosphere:
  2. Carbon Dissolves into oceans or CO2 is absorbed by plants and algae.
  3. Plants convert CO2 into carbohydrates during photosynthesis.
  4. Carbon is; Consumed by another organism, respired (released as CO2), stored in organisms, excreted as waste products.
  5. Decomposers break down waste
  6. It is either released as CO2 into the atmosphere or released as simple C compounds into soil.
  7. C carbons form fossil fuels
  8. Fossil fuels burnt, releasing CO2.
• Wavelengths


  Longer wavelengths. Eg: Radio Waves

  Lower frequency

  Lower energy

  Shorter wavelengths: Gamma rays

  Higher frequency

  Higher energy

  
• Greenhouse Gases


  Greenhouse gases are atmospheric gasses that absorb/ reflect heat, keeping the earth warm.

  They do this by absorbing infrared radiation from the sun and then emitting this radiation back to earth.
• Examples of greenhouse gases


  Water vapour:

  Produced mainly from the evaporation of liquid water.

  Carbon Dioxide:

  Produced mainly from complete combustion of carbon-containing substances (burning fossil fuels)

  Methane: Produced by decomposition of organic matter and digestion in animals.
• Short vs. long wave radiation


  Short wave length radiation is high energy, whilst long wavelength radiation is low energy.

  Short wave energy is energy that comes directly from the sun.

  Long wave radiation is emmited by the earth when the sun's shortwave energy warms it up.
• The Natural greenhouse effect


  A natural process which is responsible for heating the earth's surface.

  The steps are:

  1. The sun releases electromagnetic radiation
  2. Most radiation enters our atmosphere
  3. Shorter wavelengths are absorbed by the earth's surface. Longer wavelengths are are radiated by the the earth's surface
  4. Some radiation escapes into space. Some is absorbed by greenhouse gases.
  5. Greenhouse gasses then re-radiate this radiation, so the heat remains trapped.
• Causes of the Enhanced greenhouse effect


  Human activity is one of the main causes of the enhanced greenhouse effect.

  Human activity has severely increased the amounts of greenhouse gasses in the atmosphere.

  Deforestation and combustion of fossil fuels (for transportation and industry) increase carbon dioxide emissions.

  Animal farming and rice farming both contribute to increased methane emissions.
• What happens in the enhanced greenhouse effect


  In the enhanced greenhouse effect, elevated levels of greenhouse gasses cause more radiation to be absorbed, reducing the amount if heat escaping into space.

  This leads to an increased re-radiation of heat towards Earth, causing a rise in atmospheric temperatures.

  The consequence is a warming of the Earth's surface beyond normal levels ( Global warming), with significant impacts on ecosystems and climate systems globally.
• Weather


  The conditions in the lower part of the atmosphere at a given place and time
• Climate


  The average weather conditions in a particular regions over an extended period
• Global warming


  Increase in the Earth's temperature due to the presence of certain human-made gases.
• Climate Change


  A change in global or regional climate patterns.
• Importance of maintaining equilibrium of carbon dioxide levels


  The carbon cycle is vital to all life on earth. Maintaining this carbon balance allows the planet to remain hospitable for life. Carbon helps to:

  • regulate the earth's temperature
  • Makes all life possible
  • Major source of the energy to fuel our global economy.
• How does Global Warming affect life on earth


  The earth's rising temperatures are having a catastrophic effect on our global climate with increased:

  1. Loss of Biodiversity
  2. Agriculture
  3. Rising sea levels
  4. Increased natural disasters
• Global Warming- Biodiversity loss


  Climate change has disrupted the distribution and number of species = possible extinction.

  Arctic and antarctic animals are most at risk.

  Rising sea levels lead to the loss of habitats.

  Natural disasters increasing. Eg: Fires
• Global Warming- Agriculture


  Increased periods of drought and disruption to rainfall put agriculture at risk.

  Natural pollinators. Eg: bee's reducing in number.

  Rising temperatures result in decreased crop yeilds
• Global Warming- Rising Sea levels

  Higher atmospheric temperatures cause continental ice sheets and glaciers to melt.

  Melting of land based ice and thermal expansion of water has led to rising sea levels.

  Sea ice declining at a rate of 13% every decade.
• Global Warming- Natural Disasters

  Number of extreme weather events increasing.

  More extreme rainfall and winds

  Cyclones intensify over warm ocean waters.

  Destructive flooding

  Australia has more bushfires