I believe "chemtrails," are mostly made of water vapor.
There is no doubt sulphur and other exhaust materials (much like autos, heavy trucks, chimneys, etc.) are mixed in, so in that regard, they can be labeled "chemtrails."
But jet engines are so much more efficient at burning fuel nowadays, I think most of it is water vapor.
So you think more efficient engines destroy sulfur and other impurities?
No.
Did you even read my post?
The exhaust contains sulphur and other materials such as regular soot mixed in.
There is less of this (on an individual basis) today than yesterday because of higher efficiency combustion and fuel mixtures; however, due to more flights there are more exhaust trails...
So, net benefit = ?
The only thing taking place is the normal combustion process.
There are no extra containers of chemicals being turned on and off to mix into the jet exhaust.
The only thing you see is a jet exhaust or contrail.
But, because combustion pollutes, it could be technically called a chemtrail.
But so could your automobile exhaust.