As far as I understood the model for the Gulf Stream, was that the increase in birthed Icebergs in the Artic. Along with release of cold water as they melt, would cause the stream of warm equitoral water to be diverted further south. Thus increasing ambient temperatures in one area, while causing a decrease in Northern Europe. Which in turn would cause the British Isles to start to have winter on a power with Canada.
As to the assertation that a hugh chunk of ice falling into the sea, and causing a Tsunami (sp). B0ll0ck$. The ice-sheet at the Artic are sea ice, namely that it floats, with 80 odd % of this underwater, and thus already displacing a larger proportion of water that the sea. Even a huge chunk of the Antacrtic ice-sheet breaking away, while worrying, is not going to cause a Tidal Wave.
Edit - Though I will be going to see the movie. Nothing like seeing American cities being destroyed by............................ anything really.
