And, rightly or wrongly, that shared language will likely be English. It is already the language of commercial aviation, and it is the language that people in Europe (any other places presumably) use to talk to each other when they don't share a native language. And sometimes even when they do.

It is in some ways a bit peculiar, with a simple grammar but extensive vocabulary (much of which thieved from other languages). It is on the face of it quite ugly, however great poetry and works of literature have been created using it. Some non-native speakers say they feel freer using English instead of their native tongue, but of course that is a somewhat nebulous proposition hard to substantiate, even if there is a little truth to it.