Ok so there is this movie I saw when I was a kid, its about global warming. Its similar to 'the day after tomorrow'. Basically everything freezes. And I just kind of remember the ending.. a submarine saves a group of people. Please help me rememeber the name of this movie.

Not sure how old you are, but maybe this:

Ice (TV 1998) - IMDb (http://www.imdb.com/title/tt0160393/)

Or this:

http://en.wikipedia.org/wiki/Absolute_Zero_(film)