toxic.They only become harmful to
the earth over long periods as trapping for
heat radiation from the earth during the day and at night.
Contrails are those 'smoky-line' emissions
noticeable in the sky from airplanes.This carbon emissions from burning fuels first crystallizes,then,condenses at low humidity,low temperature,reduced pressure with high altitudes.The resulting emissions are actually 'CLOUDS' not toxins.
Emmys-hub
Emmys-hub