Unit 8 - Greenhouse Effect, Global Warming and Climate

• 3 things that can happen when sunlight hits the Earth

  1. Reflected back to space (this is why we can see Earth from space)

  2. Pass through the Earth (not very likely with our Sun)

  3. Absorbed by the planet and heat it up

  - As a result the Earth is warmer than surrounding space
• Black Body Effect


  - objects that are warmer than their surroundings will radiate energy out

  - the wavelength of this energy depends on the temperature of the object

  - Earth, Sun, Poker in the fire are all....bodies"

  - Earth is 15 degrees C

  - Sun is 5800 K(alvin)
• Greenhouse Effect


  - CO2, CH4, N2O trap heat in the atmosphere making it warmer than usual which allows for life on Earth, and why we're warmer than the moon.

  - Infrared Radiation leaves the 15C Earth and heads to space

  - O2 and N2 are INVISIABLE to IR
• Global Warming (what happens if we increase our Greenhouse Gas concentration?)

  - an increase in energy contained in the atmosphere due to a rise in the concentration of greenhouse gases

  which will...

  - It will deepen troughs

  - the further the actual is from the blackbody line, the more heat energy is in the atmosphere

  - if humans are responsible it's called "anthropogenic .... ....."
• 3 Key Gases Contributing to Global Warming (that are anthropogenic) (natural)

  1. Co2 - the result of burning fossil fuels and burning of forests

  - Up 40% since the industrial revolution

  2. CH4 (methane) - from cows and rice patties

  - Up 150% since the industrial revolution

  3. N2o - from production of fertilizers

  - Up 20% since the industrial revolution
• Climate Change


  the change in long term weather patterns, include temperature, precipitation, wind, etc, due to an increase of energy in the atmosphere

  Weather - today's temperature is -9 in Winnipeg

  .... - Winnipeg gets 25.5 mm of moisture