Why Did Global Warming "Tip"? (Part II)

My second post on this subject is now up at Huffington Post. Check it out. The first post, published yesterday, is here. Read together, in order, I think they make for a pretty comprehensive essay on the subject at around 2,000 words in length. I want to emphasize that I couldn't have written any of this without Nisbet's research, and want to give credit where it is way due.