Global Warming: Anthropogenic Effects

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Global Warming Anthropogenic Effects
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Systems and Loops

• A system a group of independent parts working
  together as a whole (e.g. human body)
• Positive Feedback Loop Part of a systems output
  is fed back to input and increases effects of
  interacting parts

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Negative Feedback Loops

• Decrease the effects of interacting parts to
  maintain equilibrium. To prevent, slow or reverse
  changes. Keep Homeostatic levels.

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Energy Transfer

• Conduction
• Transfer of thermal energy between 2 objects
• E.g. metal pot on stove transfers heat from
  element to water in pot
• Convection
• Transfer of thermal energy by highly energized
  molecules moving from one place to another. Fluid
  create currents
• E.g. ocean currents, wind currents
• Radiation
• Transfer of thermal energy from the sun to the
  earth. Electromagnetic radiation can travel
  through the vacuum of space heating up our planet

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Energy Transfer In Oceans

• Warmer surface water
• Heated by radiation
• Less dense because warmer water so stays at
  surface until current takes it N then the air
  cools it and it sinks (convection)
• Moves quickly at surface
• Cold dense deep water
• Moves slowly at bottom of ocean
• Pushes warm water our of the way as it sinks
• More salty and dense

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Ocean currents Conveyor belts of energy
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Cycles of weather
Periodic warming cooling of a huge mass of sea
water. Impacts weather in N. America.

• El Nino
• Heavy rains
• Warmer than normal
• Warm air brought by Jet streams across the Pacific

• La Nina
• Dry, drought
• Cooler than normal
• Warm air cool moisture pushed away from North
  America

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El Nino La Nina


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Green House Gases

• 90 of atmosphere made of N2 and O2. They dont
  absorb infrared radiation
• Water 1-4
• CO2 0.036
• Water Vapour
• Most abundant greenhouse gas
• Not increasing in amount. Humans dont release
  more of it

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CO2 and Methane

• Carbon Dioxide
• Main source Animal respiration
• Main human source?combustion of fossil fuels and
  fires
• Main sink is plants and photosynthesis
• Deforestation removes sink factors
• Methane
• Main source? bacteria that breakdown waste matter
• Main source? bogs and swamp lands- increase in
  decomposing matter
• Sink? can be collected used as a fuel
• Sink?start eating Kangaroo instead of cow.

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Anthropogenic Effects

• Anthropogenic Greenhouse Effect
• Since 1750 humans have increase CO2 levels mostly
  from burning fossil fuels
• Deforestation Agriculture
• Industrial activities
• Methane has increase 1045 ppb
• CO2 has increase 104 ppb