Those are called con-trails, as in condensation trails. It is just water condensate forming on the jets of a plane similar to how water condensate forms on a cold glass of water in a warm room. Actual geo-engineering looks a little bit different and behaves completely different to con-trails as the goal for geo-engineering is to disperse something over a large area relatively fast meaning that it would soon (within seconds) no longer be visible. If th government were attempting to create 'chem-trails' then they could do so in a much better way than making them look like con trails, and they could more efficiently disperse such chemicals through other means, as in flying above an area and dispersing chemicals isn't very efficient when you could just add those same chemicals to the water supply and hope people don't use a RO filtration system but considering so many people view RO water as super toxic (especially those whom tend to believe in chem trails) you have a perfect dispersion system.
RE: Chemtrails : No Vacation Time for Atmospheric Geoengineering