You still have to make decisions about your own life. Are you going to settle down in region that is expected to dry up or be hit by mega-storms?
Will people migrate over time? Yes. Does migrating now vs. later make a difference? Much less certain - because those people migrating later? They're probably going to the same places the "migrate now" people have moved to. And at that point, it's going to be wholly unpleasant for both groups.
I mean, yes. Don't buy farm real estate in Arizona, or waterfront property in Miami.