Please see artificialclouds.com for current documentation. This documentary should make you think twice, before dismissing persistent tracks in the sky, from condensation trails, or "chemtrails."
Skywatcher is a 25-minute science presentation, discussing weather modification and the REAL cause of climate change, which is anthropogenic CLOUD cover-- much more than greenhouse gases like CO2-- and the spraying of "cloud seeding" chemicals (especially silver iodide) for precipitation enhancement.
This video shows exactly HOW we make clouds with aircraft, why the jet contrails persist now (when they used to disappear much more quickly), and why we're finding high levels of metals in our water and soil, including aluminum and strontium. ... Are you sure you want the truth?
The dramatic suggestion by this documentary, that cloud seeding is a wholesale practice carried out by governments needs some qualification. In Australia, it has only been done experimentally in about 3 choice places Tasmania, Melbourne , and the Snowy Mountains, by one company for 40 years, and the results are controversial that it even works. A storm of pseudo-skepticism reigns ! But with 46 yrs of records, statisticians, were finally able to find a 5% signal justifying all the money spent.
And in this recently televised, scientific update, below, it is explained that this particular method of rain making, cannot be applied everywhere.
Seriously, in my 50 yrs in Australia, I have never seen government cloud seeding, or large scale cloud seeding, mentioned in mainstream media. In our 10 yr drought around 2000, there were numerous government calls to private industry to do something. Colourful suggestions, were obtained but the drought was ended by La Ninya, not by fleets of government aeroplanes.