According to climatologist Jack Hall the registered global warming could trigger a sudden catastrophic shift in the planet's climate. He tries to inform politicians about the outcome of his recent research but to no effect. In the meanwhile rock-sized halestones hit Tokyo, a hurricane pounds Hawaii and Los Angeles is whiped off by fierce tornadoes. Soon after urging politicians to evaquate the population to the southern part of the continent he heads towards New York to save his son Sam, who has been trapped by ice age temperatures in a library.