When global warming triggers the onset of a new Ice Age, tornadoes flatten Los Angeles, a tidal wave engulfs New York City and the entire Northern Hemisphere begins to freeze solid. Now, climatologist Jack Hall (Dennis Quaid), his son Sam (Jake Gyllenhaal) and a small band of survivors must ride out the growing super storm and stay alive in the face of an enemy more powerful and relentless than any they've ever encountered: Mother Nature!