The following new web site and video makes the claim that the increased incidence of contrails and global climate change are both caused by silver iodide cloud seeding in the stratosphere.
While the science discussed in the film is mostly nonsense (cloud seeding does not take place in the stratosphere, and excess silver iodide would precipitate out in ice supersaturated conditions, so would not contribute to contrail formation, and basically zero water is added to the atmosphere by jets compared to what is already there), it's a well made film, and is likely to enter the pantheon of chemtrail mythology.
http://artificialclouds.com/
While the science discussed in the film is mostly nonsense (cloud seeding does not take place in the stratosphere, and excess silver iodide would precipitate out in ice supersaturated conditions, so would not contribute to contrail formation, and basically zero water is added to the atmosphere by jets compared to what is already there), it's a well made film, and is likely to enter the pantheon of chemtrail mythology.
http://artificialclouds.com/