Are you asking about the film Day After "Tomorrow"? If so, then there are many mistakes in the film and the science used to create the story is flimsy at best. See some examples at this link: http://www.moviemistakes.com/film4178 If you are sure that the film is Day After "Tomarrow" then I do not know because I could not locate that film name in any database.

First of all let me tell you that I don't go to disaster movies while they are in theaters. I don't go to them because I don't want to ruin the experience of the rest of the audience as I scoff at what passes for science in Hollywood. So, the first thing to remember is never trust Hollywood for you scientific information. That written, I have not actually seen "The Day After Tomorrow". However, this page (http://www.uwgb.edu/dutchs/PSEUDOSC/AtMovieDayAfterTom.htm) was written by a geologist that did. He was not particularly complimentary of the science in the movie. The up shot of the review is that, yes, there was a period of cooling (the Younger Dryas) that temporarily interrupted the general warming trend as we came out of the last ice age. The most popular theory to explain this cooling is the release of massive amounts of glacial melt water from North America interrupting the density driven circulation of the North Atlantic. The shutdown of this circulation then allegedly stopped the transfer of warm waters from the low latitudes into the high latitudes. Thus causing the cooling. The author of the above cited article correctly points out that such a situation i not possible today. There simply is not enough water tied up in glaciers to do this now. Furthermore, the premise of the movie is that the fresh water is provided by the breakup of a substantial amount one of the Antarctic ice shelves. The problem with this is that it is doubtful that such an event would deliver the necessary water fast enough. However, even if it did, it would not affect the circulation in the NORTH Atlantic. There are, however, some other problems with this theory. First of all, it is not the density driven circulation that in the oceans that is most responsible for the transfer of heat from the low latitudes to the high ones. It is the surface currents that do this. The surface currents are created and driven by the winds. The winds would keep blowing even if there were a layer of fresh water on top of the ocean. So, the surface current would keep moving heat to the higher latitudes. The other problem with this theory is that there are other possible explanations. One that is gaining some acceptance is that the Younger Dryas was actually triggered by a meteorite impact (http://www.pnas.org/cgi/content/abstract/0706977104v1). So, the whole idea of melt water causing the cooling could be wrong. So, that is my perspective on that particular movie. Take it for what it is worth.