We have all seen photos and videos showing one plane making a trail and another near it not making one.
This is another scam to make you think chemicals are being turned on and off.
And this is how we are told we can tell a contrail from a chemtrail. This is false because all trails use the same fuel. During modern times, all trails are chemtrails; it is the humidity that controls their duration
The controlling factor for the growth of a trail is the RHice, but the humid layer is usually very thin.
This graph shows the atmospheric conditions from the ground up.
Where the temperature line on the right touches the thin ice line in the centre, that is the height at which saturation is present. At 8,350 meters only, any plane travelling slightly higher or lower will not leave a trail, even when using modern fuel.
