Last week Al Gore warned Wall Street movers and shakers to rethink their investments in carbon-intensive businesses. Carbon won't be free forever and a business's carbon footprint will soon be priced into its value. "Subprime carbon assets" are poised to collapse.

Most people agree that wanton, unrestricted production of carbon dioxide is bad (we're certainly convinced) but he seems to be suggesting that companies are going to be forced to account for their environmental impact in a new way soon. Sounds great, but what's going to make that happen? Is he predicting new, stricter regulations? (Fingers crossed.)