`The fundamental problem here is that the climate is a big system, with many little systems operating inside it. Within all of these systems there is always operating one huge simple negative (stabalising) feedback, which is S=rT^4. So no matter how large a process is at providing ``positive feedback`` within the system - like ice-albedo feedback, say - the *overall* system remains stable (except for quibbles like D-O osc etc; but even they are bounded). Trying to define ``positive feedback`` by analogy with electronic circuits, but forgetting that in those circuits only one feedback operates, only leads to confusion     `