Diego, Manny and Sid return in this sequel to the hit animated movie Ice Age. This time around, the deep freeze is over, and the ice-covered earth is starting to melt, which will destroy the trio's cherished valley. The impending disaster prompts them to reunite and warn all the other beasts about the desperate situation.

After years of increases in the greenhouse effect, havoc is wreaked globally in the form of catastrophic hurricanes, tornadoes, tidal waves, floods and the beginning of a new Ice Age. Paleoclimatologist Jack Hall tries to warn the world while also shepherding to safety his son, trapped in New York after the city is overwhelmed by the start of the new big freeze.