The primary concoction used in the chemtrail program is refined Fly Ash which is a toxic byproduct of Coal power plants, a program which is managed and coordinated by a secret branch of the US Navy, and is done mostly using private contractors. Interestingly enough geoengineering is only 1 of over a dozen aspects of the overall program (which ranges from geoengineering, to over-the-horizon communication, to ground-penetrating radar/tomography, to atmospheric 3D holographic display and much more).

Sadly most people still deny the chemtrail program even exists, and today it is much harder to convince new people about its existence then it was a few years ago (as we are now in the upkeep phase... 1998-2008 was the seeding phase which was far more obvious and required a much larger amount of spraying then they do now).