Humans have played too much with nature. It is time for penitence. As there is a huge storm due to the melting of the polar ice caps. The storm envelopes the entire northern hemisphere bringing in a new ice age there. All climate forecast models fail. Jack Hall (DQ), a climatologist, walks in with a model based on pre-historic data. After being rejected a multiple number of times his theory is finally accepted after the storm actually hits.

The entire northern part of US goes under ice even as people struggle to survive. The people from the southern half of US are evacuated into third world countries like Mexico. The people from the northern half can't even be evacuated, its already too late. Watch what happens as Jack sets out to rescue his own son Sam(JG) who is stuck in New York city.