California Content Standard

Earth Science, 4.c.

Students know the different atmospheric gases that absorb the earth’s thermal radiation and the mechanism and significance of the Greenhouse effect.

 

 

I.                    The Global “Greenhouse”

A.     Heat from the sun becomes trapped in the atmosphere and is radiated back down to the earth’s surface

Molecular

1.      CO2 absorbs E (energy) at infrared wavelengths.

2.      Without CO2, energy at these wavelengths would pass through the atmosphere and back into space.

3.      T=30-40’ cooler without greenhouse effect.

II.                 Rising CO2 Levels

A.     Burning of fossil fuels release CO2

B.     Data    

1. Since industrial revolution, 290-330 ppm (Parts per million.)

2.      Last 25 years there was a 6% increase.

3. Last 22 years 78 billion tons of CO2 released

3.      Mauna Loa data (1958-1988)

C.     Deforestation

1.      Releases stored carbon

2.      Loose means of CO2 removal

 

III.               Impact on Climate?

A.     Assuming current trends continue, 2xCO2 by 2020= increased 0.3 degrees Celsius/decade

1.      Melt polar ice caps leads to a rise in the sea level of up to 4 feet.

2.      Currents driven by T differences weaken which leads to extremes in T in costal areas magnified

3.      Rainfall: Rain belt shifts toward the poles. May disrupt farming patterns.

 

Question: What can we do?

Question: What should we do?