What you’re talking about are positive feedbacks. ‘Positive’ only in the sense that they add to the increase in the warming. The climate has a bad habit of feeding off of itself. If it is cooling, then things happen naturally that make it cool faster. And scientists are finding everywhere they look that these feedbacks are kicking in right now……much sooner than they predicted.

Here is more about the feedbacks:
Think Not ‘Global’ Warming – Think ‘Oceans’ Warming
http://portland.indymedia.org/en/2007/11/369083.shtml