I fully expect in coming years

[keep_left]

5. It's very unlikely, for reasons that are a bit over my head, actually...

...but it comes down to the fact that the oceans would have to get much hotter. Raising the temperatures of the world's oceans requires one hell of a lot of energy; those waters are basically a giant heat sink. What (I think) you're describing has been called a megacane/hypercane/etc. It would make for a good movie, though...maybe they already made it, as another poster mentions.