Getting off the fence

The news that professional doubter Michael Shermer (that's him on the right) has finally decided to get off the fence and accept the scientific consensus on climate change serves as an excellent entry point for a look at the philosophical justification for skepticism.

In his latest Scientific American column, the editor of Skeptic magazine admits to being a "skeptical environmentalist" for quite a while, thanks to what he calls "failed" predictions of ecological "doom and gloom" in the 1970s. I would argue that those predictions -- overpopulation, resource depletion, starvation -- are merely unfulfilled or exaggerated rather then failed, but his point is well taken. He accepted those dire warnings and felt betrayed when they didn't come to pass. Fair enough.

"Nevertheless," he writes:

...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.
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Four books eventually brought me to the flipping point. Archaeologist Brian Fagan's The Long Summer (Basic, 2004).... Jared Diamond's Collapse (Penguin Group, 2005).... Elizabeth Kolbert's Field Notes from a Catastrophe (Bloomsbury Publishing, 2006).... And biologist Tim Flannery's The Weather Makers (Atlantic Monthly Press, 2006).
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Because of the complexity of the problem, environmental skepticism was once tenable. No longer. It is time to flip from skepticism to activism.

Yes it is. Just today, for example, one of the more troubling reports I've seen in months caught my eye: "A team of European scientists reports that climate change estimates for the next century may have substantially underestimated the potential magnitude of global warming." In a paper to appear May 26 in Geophysical Research Letters, the team concludes that

Although there are still significant uncertainties, our simple data-based approach is consistent with the latest climate-carbon cycle models, which suggest that global warming will be accelerated by the effects of climate change on the rate of carbon dioxide increase. In view of our findings, estimates of future warming that ignore these effects may have to be raised by about 50 percent.

We could debate about just when it was that environmental skepticism lost its tenable status, of course. It's a subjective thing. Everyone's got their own threshold or, to use a hip phrase, "tipping point." I'm not sure why it took Shermer so long, when so many climatologists had made that shift ages ago. But the important thing is one of the world's premier skeptics no longer finds it necessary to doubt the evidence.

Shermer is one of those scientists who prefers to describe himself primarily as a skeptic (although he won't object to being called a "humanist, secular humanist, agnostic, nonbeliever, nontheist, freethinker, heretic, or even bright"). Aside from being remarkably smart, he also seems to be a fairly decent fellow, one who agreed to publish an essay I wrote a while back. So I like the guy. But even I have found myself occasionally frustrated with his hard-core skepticism, and his prior approach to environmentalism was a prime example. At the end of the day, it seemed he doubted mostly because he liked doubting. Doubting was what he did best. Doubt as an end in of itself.

But can doubt be its own end? Shouldn't skepticism merely be a tool for understanding the universe? I think so. After all, it's important to keep the eye on the prize: making sure our models approximate reality to the greatest degree possible. It's easy to stand back and dismiss an activist's argument as unfounded, unwarranted or precipitous, and I think too many of us take a fair bit of pleasure in playing the skeptical holdout, whose standards are just that much higher than the gullible masses.

The climate change debate is rife with self-proclaimed skeptics who get a little too used to those boots. It takes a bit more courage to admit that maybe the activists are right after all.

I'm relieved that Shermer has joined those of us who have concluded that "the balance of evidence suggests a discernible human influence on global climate," as the fine folks at the IPCC said 11 years ago. My characterization of his obsession with doubt may have been unfair. But it's even better to be reminded that skepticism has its limits. At some point, the call for "more research" begins to sound like the theme song of those with their heads in the sand.

Skepticism about skepticism. A little meta-skepticism, if you will, can be a good thing, even on the Island of Doubt.