Now, how the hell did he do it?
Let's assume humanity manages to turn the earth into a dead fish tank. We have the tech to go to a nearby star system with shitloads of planets and moons, terraform those babies, and resettle there.
It's your pioneer situation. I.e.: it ain't fun.
Chances are, the pioneers would speak some garbled, rough-and-ready lingo.
M'luv, obaachan wen bungie jump dis ohio. Wat!?! Azfoo!
A mash-up of tongues a la Gaff's "Cityspeak" in Blade Runner.
Of course, nobody in the 21st century would understand a solitary slovo.
So, letting some screenwriterish approximation of oldwesternese and Chinese stand for the future slang is the next best thing.
I'll buy it.