We feel rising and lowering temperatures throughout the course of our seasons. Couldn't the rising temperature of the Earth just be part of a natural up and down cycle?

Gore agrees that the planet's temperature has indeed experienced up and down cycles, but he says the current up cycle is too extreme. "It's way off the charts compared to what those natural fluctuations are," he says.

No place is immune to global warming, Gore says. "Of the thousand largest glaciers on every continent, 997 of them are receding," he says. "And it's not seasonal."

"Scientists say if we let it get that high on the warm side it would be an utter catastrophe, and it would be unethical and immoral where our children are concerned."