Does the global economy really need passenger planes? Tourism economies, sure, but I would guess most of the economy is dependent on trains, trucks and ships?
People certainly immigrated before the airplane, but in general those were individuals without many options at home. Skilled immigration really took off during the Jet Age.
In France the train is ~50 x more carbon efficient. We will not be able to keep emitting like crazy forever (we actually should have stopped completely already :/ ) , especially when reasonable alternatives exist (the train if going not too far, teleconferences, ...). If we believe in the markets, the price of an air ticket should be maybe 50x higher than what it is today, in order to stop the insane emissions. Alternatively there could be an authority who decide if we have a good reason to take the plane.