climate change

• what is the green house effect?

  The trapping of heat in the Earth's atmosphere by greenhouse gases.
• the greenhouse effect maintain the Earth's average temperature
• what are the 3 types of human causes?

  fossil fuels, agriculture and deforestation
• fossil fuels:

  • many power stations across the world burn fossil fuels to generate energy
  • the 3 fossil fuels are coal, oil and gas
  • when fossil fuels are burnt, they release carbon dioxide and pollutants.
  • 270 tonnes of CO2 emitted from fossil fuels
• agriculture:

  • responsible for 14% of all emissions
  • cattle product 120kg of methane per animal
• deforesation:

  • rainforests now only cover 5% of the worlds surface
  • trees counter the emission of CO2
  • carbon released when trees are cut down
• natural causes:

  Milankovitch cycles:

  • long term changes to the earth's orbit and position
  • this changes how much solar radiation the earth recieves.
  • earth's orbit changes every 100,000 years (circular orbit = cooler, eliptical orbit = warmer)
  • tilt varies every 40,000 years (greater tilt = hotter)
  • every 24,000 the earth wobbles on its axis (precession), which can change the seasional temperatures
• natural causes:

  volcanic eruptions:

  • large scale eruptions --> vast amounts of ash being ejected into the atmosphere
  • this ash blocks solar radiation, leading to a decrease in temperature
• natural causes:

  sunspot activity:

  • increased activity = higher average temperatures
• natural causes:

  atmospheric dust:

  • asteroids/meteors entering earth atmosphere may increase amound of dust
  • may decrease temperatures.
• social effects of climate change: HEALTH

  • increased temperatures and lack of precipitation may lead to spread of disease. (water born disease)
  • heat strokes may become more frequent (those with respiratory diseases such as asthma may be more affected)
  • diets may be restricted by food shortages leading to malnutrition and famine
• social effects of climate change: EMPLOYEMENT AND HOMES

  • Loss of job opportunities due to changes in tourism and agriculture
  • Increased flooding due to sea level rise and increased frequency and severity of storms will lead to displacement of large numbers of people
• economic effects of climate change:

  AGRICULTURE:

  • Coastal flooding may lead to salt intrusion
  • Reduced availability of water will mean that irrigation is limited or impossible
  • Food shortages will lead to malnutrition and famine

  EMPLOYEMENT:

  Job opportunities may change or decrease because:

  • Tourism may decline in some areas for example ski resorts may close due to the lack of reliable snow
  • Coastal resorts may be at risk of flooding leading to the closure
  • Farmers may have to change the crop they grow or livestock they raise or leave farming