Chris Mooney on the global warming tipping point

In my recent conversations with peers in the science policy world (read “fellow geeks”), the same question has come up repeatedly of late: Why did global warming “tip”? How has the issue finally managed to go mainstream, so that even President Bush now seems on the verge of feeling its urgency?
Chris Mooney, author of the new book, Storm World, has a piece on Huffington Post today describing his thoughts on how global warming has moved into the spotlight as a major issue in America.