This is an example of a positive feedback.Another thing that happened during past climate changes was that when the warming occurred, more ice melted, as I talked about in the last topic.And of course, when the ice melts, more dark surfaces are exposed, leading to more warming.This is yet another example of a positive feedback.The really important thing to remember about these past climate change is that they occurred very, very slowly.The Earth warmed or cooled just a few degrees over