What Chemtrails Really Are
http://www.rense.com/general79/chem.htm
They spray barium powders and let it photo-ionize from the ultraviolet light of the sun. Then, they make an aluminum-plasma generated by "zapping" the metal cations that are in the spray with either electromagnetics from HAARP, the gyrotron system on the ground [Ground Wave Emergency Network], or space-based lasers. The barium makes the aluminum-plasma more particulate dense. This means they can make a denser plasma than they normally could from just ionizing the atmosphere or the air.
More density [more particles] means that these particles which are colliding into each other will become more charged because there are more of them present to collide. What are they ultimately trying to do up there -- is create charged-particle, plasma beam weapons.
Chemtrails are the medium - GWEN pulse radars, the various HAARPs, and space-based lasers are the method, or more simply:
Chemtrails are the medium -- directed energy is the method.
Spray and Zap.