Posted 10/19/2016 20:14 (#5590274 - in reply to #5590192) Subject: RE: Con trails - chem trails
The contrails are condensed engine combustion products. Primarily water from burning hydrocarbon fuel. There is also more carbon dioxide but it doesn't condense at ordinary upper atmosphere temperatures. If the air layer is dry or warm, the water vapor doesn't condense either into those string clouds we call contrails.
Con trails - chem trails
