The Earth has heated and cooled itself for it’s entire existence. It cooled off to produce numerous Ice Ages and then heated up again all on it’s own to end those Ice Ages <br><br>Point being the Earth hearing or cooling is a natural phenomenon and we humans are naive if we think otherwise,(reply>), If there where no humans on earth, the earth's average temperature would be slowly decreasing.,(reply>), Except we're the ones heating it up. This is not a natural phenomenon