Airplane/ Aeroplane fuel efficiency

Airplanes use the vast majority of their fuel relative to  horizontal distance traveled, on takeoff  and relatively little cruising at high altitudes and on descent.

Short flights of perhaps up to 3 hours  are therefore the most wasteful and carbon polluting.

These short flights  could be curtailed where there are alternatives such as delaying meetings or online meetings or efficient ground transport, however long haul international flights which are by far the most efficient and have no alternative should be resumed as soon as possible for the sake of bringing the worlds peoples together not separating them.