Michael Shermer on why he's no longer a global warming skeptic

From his latest Skeptic column at Scientific American

Nevertheless, data trump politics, and a convergence of evidence from numerous sources has led me to make a cognitive switch on the subject of anthropogenic global warming. My attention was piqued on February 8 when 86 leading evangelical Christians--the last cohort I expected to get on the environmental bandwagon--issued the Evangelical Climate Initiative calling for "national legislation requiring sufficient economy-wide reductions" in carbon emissions.

Then I attended the TED (Technology, Entertainment, Design) conference in Monterey, Calif., where former vice president Al Gore delivered the single finest summation of the evidence for global warming I have ever heard, based on the recent documentary film about his work in this area, An Inconvenient Truth. The striking before-and-after photographs showing the disappearance of glaciers around the world shocked me out of my doubting stance.

Four books eventually brought me to the flipping point. Archaeologist Brian Fagan's The Long Summer (Basic, 2004) explicates how civilization is the gift of a temporary period of mild climate. Geographer Jared Diamond's Collapse (Penguin Group, 2005) demonstrates how natural and human-caused environmental catastrophes led to the collapse of civilizations. Journalist Elizabeth Kolbert's Field Notes from a Catastrophe (Bloomsbury Publishing, 2006) is a page-turning account of her journeys around the world with environmental scientists who are documenting species extinction and climate change unmistakably linked to human action. And biologist Tim Flannery's The Weather Makers (Atlantic Monthly Press, 2006) reveals how he went from being a skeptical environmentalist to a believing activist as incontrovertible data linking the increase of carbon dioxide to global warming accumulated in the past decade.

Speaking of Gore's movie, I was somewhat surprised to see that The Economist, hardly a magazine that can be accused of global warming alarmism, gave an overall positive appraisal of the movie, writing:

Mr Guggenheim's film is a fascinating and alarming polemic that does, indeed, set out to speak to everyone. It was inspired by the lectures and slide-show on global warming that Mr Gore has delivered more than 1,000 times since he failed to become president. The former vice-president is shown talking about what he calls “our planetary emergency” to groups of concerned Americans, displaying the relaxed charm and sense of humour that he notably lacked as a political campaigner.

I hadn't planned on seeing the movie, but the review piqued my interest. Eric Steig of Real Climate offers his opinion of the science in the movie, here.