George F. Will on the changing climate for a global warming treaty - washingtonpost.com

In their new book, "SuperFreakonomics," Steven D. Levitt, a University of Chicago economist, and Stephen J. Dubner, a journalist, worry about global warming but revive some inconvenient memories of 30 years ago. Then intelligent people agreed (see above) that global cooling threatened human survival. It had, Newsweek reported, "taken the planet about a sixth of the way toward the Ice Age average." Some scientists proposed radical measures to cause global warming -- for example, covering the arctic ice cap with black soot that would absorb heat and cause melting.