Taking that “red eye” overnight flight is more damaging to the environment than daytime air travel because contrails cause more global warming after dark. Winter flights are also harder on the environment than summer flights. And blocks of ice that crash suddenly from the sky are a sign of global warming, since they?re caused by freezing contrails.
Contrails warm the earth by trapping heat and keeping it from escaping, but they ALSO cool it by reflecting sunlight back into space. These two functions balance each other out during the daytime, but at night, the cooling effect is not in place, so the warming effect is greater.