Produced as part of the Bell Laboratory's series of educational science films, "The Unchained Goddess" is certainly campy ... but spookily prophetic too, considering it was made in 1958. In it, a narrator dubbed "Dr. Research" issues a warning that could be cribbed from an Al Gore powerpoint presentation:

"Even now, man may be unwittingly changing the world's climate through the waste products of his civilization. Due to our release through factories and automobiles every year, of more than 6 billion tons of carbon dioxide"¦ our atmosphere seems to be getting warmer."

Just twenty years later, even more folks were worried about the ways we power our country, this time because of the 1970s oil crisis. This educational film, called When the Circuit Breaks, looks at how demand for traditional sources of power was even then outstripping supply, examines alternative power sources like solar and wind, and envisions a 1985 in which the U.S. would be energy independent.

Reaching way back into the vault, here's a clip from the 1939 Jimmy Stewart flick You Can't Take it With You, in which Stewart's character dreams of being able to harness the power of the sun; the "secret of all those millions of little engines" which turn sunlight into energy: plants and trees.

I found "Unchained Goddess" via Redgreenandblue.