Presciently, the movie Soylent Green (1973) specifically mentioned elevated temperatures due to global warming as part of the general ecological breakdown. It’s why everyone was depicted as sweaty all the time; and why Thorn and Shirl celebrated the last paid-for month at the dead millionaire’s apartment by cranking up the A.C. to make it “as cold as winter used to be”.
It’s a phrase in Klingon. I think it translates to “I study Klingon.”
While the alien Klingon species was created in the 1960s, for the original Star Trek series, in that show, they only spoke in English. A fictional Klingon language wasn’t constructed until Star Trek: The Motion Picture, released in 1979, and it only consisted of a few phrases until sometime in the 1980s or 1990s.
In other words: no one could have said anything in Klingon in 1975, because the language hadn’t been created yet.