Here's an authoritative discussion from the NOAA: http://www.aoml.noaa.gov/hrd/tcfaq/C5c.html
Some wacky ideas here, including using submarines to pump cold water from the ocean depths to the surface to disrupt convection currents: http://www.environmentalgraffiti.com/meteorology/news-subver...
As to the origin of the idea, all I could find was that it was first proposed in the 1950s (but no source.) That makes sense given that it's an obvious thing to try with a new H-bomb toy. I couldn't find any evidence that the Ploughshares program* in the '60s ever considered it, so I expect the idea was shot down after the first back-of-the-envelope calculation.
*Ploughshares was an exploration of peaceful uses of nuclear explosives. Turns out they're only really good at digging really gigantic holes that you can't use for 50,000 years.
(Edit: ChuckMcM, commenting below, has actually been to a Ploughshares crater and since he didn't die I'll admit that "50,000 years" is poetic hyperbole, not scientific fact.)