Fun fact, contrails contribute to global warming, but only at night.

During the day they have a cooling effect by reflecting/blocking some light.

The optimal is not to eliminate them entirely, but to create them only early in the day so that they dissipate by sunset.

https://www.transportenvironment.org/te-asia-pacific/topics/... acknowledges the difference between day and night but claims that the sum of the effects still results in net warming during the day.