I am surprised that The Day After Tomorrow[/b] hasn't made an appearance yet, in this thread.
Firstly the world could NOT cool down that quick, no way.
Secondly how on earth did they get from Chicago to New York (via some other place*) and still approach from the south. On this topic, how did they manage to walk that distance in THREE days, in arctic conditions?
Thirdly, if you are in New York Central Library, the sea, and harbour, are to the EAST, so jumping on a ship which is passing, coming from the east, and hoping to get to the sea is a bit of a no hoper.
*I can't remember the other place, but it is to the north west of New York)