it allows light energy to come 
in but not go out. It is like a one-way door. And the reason it is like 
that is that CO<INF>2</INF> molecules block ultraviolet rays of light, 
light at a certain spectrum, excuse me, allows it in, allows 
ultraviolet rays from the sun in to the Earth, and that is the warming 
component coming in. But when light bounces back into space, it bounces 
back at a different frequency, at infrared frequencies.
  It holds the energy in and that is good to a certain degree, but the 
