The Day after tomorrow

“The Day After Tomorrow” is a movie about global warming. This movie I rate “You must see” which is very good. This movie is about Global Warming, but this movie is like the end of the world, the world's tempreture becomes very cold and all of the things frozen up. The problem is I don't understand why does the climate suddenly becomes very cold and froze up the people. Global Warming is making the world becomes hot, but why does this movie shows the climate becomes very cold. Is it my mistake that it's not about global warming or what is it?

Please help me to know the answer.Post a comment if you know something about this thing. I'm please if you could post a comment about this, because I'm very curious about this. Thank You.