Dude, I know meteorology, I'm storm chaser. I see climate change, but this is caused by emission of CO2, and this is fact. I know how contrails are created (clouds behind plane) and I know why sometimes they dissapear fast and sometimes they stay long.
It depend of air conditions. It's like creation of storm clouds. In good conditions the convection can lift the moist and warm air high anought to create storm cloud, but sometimes air on some altitudes is too dry, so the clouds evaporate so fast and storm didn't develop. The same thing works with contrails.