If You Think the Sky is Falling, Check out the Prophecies of the 1970s by Michael Barone
Forty years is roughly the length of a working lifetime -- and long enough for history to have taken some unexpected turns. And to have proved that long-term forecasts based on extrapolations of existing trends usually end up wide of the mark.
The list of failed prophecies from the 1970s is rather long. The conventional wisdom of the time was more than usually unreliable.