Sky Glow is what robs us of the wonders of the night sky.  Most kids in the US cannot see the Milky Way.  You may have seen this pictire and said "How lovely."   The following picture on the left is from 1992, the other is from 1999.  Isn't progress wonderful!?!

 

 

 

 

 

The lights shining up into the sky create this effect and wipe out the stars we all grew up admiring. 

To see a comparison, the first picture below was taken during a blackout.  A few nights later, the power was restored and the Milky Way disappeared. (thanks to Todd Carlson)

 

 

 

 

 

 

 

 

 

To reduce the Sky Glow, you simply have to point the light down toward the ground.  There will still be some reflectance off the ground, but only 10%-20%. Here is an example.  
 

 

Lighting up the bottom of clouds at night is a waste of about $2.2 Billion a year.  Talk to your city council, you representative and you senator about this issue.