Originally Posted by
Dantheman
Positive feedback loop.
Positive/negative doesn't refer to the desirability of the outcome, but rather whether a small change in the system will drive that system back toward or away from the current equilibrium. The climate is filled with positive feedbacks (e.g., melting ice caps exposing dark soil and water which absorb more insolation and create further heating) and negative feedbacks (e.g., warmer air holding more moisture creating more cloud cover which reflects insolation back to space and cools things back down). Modeling the magnitude and interaction of those feedbacks is an incredibly difficult task, but right now the positive feedbacks seem to be winning.