More like an avalanche. The first few rocks are falling right now, but they will be followed by an inescapable tide of debris coming down.

I think this is supposed to make the Antarctic region colder, because the cold dense water will not be making its way to the tropics. Which also implies that the tropic and equatorial regions will remain warm or become warmer. The juxtaposition of extremes should result in more violent storms for everybody in the temperate zones.

It's horrifying to think about, but in truth it would be fascinating to watch it happen.