Leah Ceccarelli of the University of Washington today writes a piece in the Seattle Times today calling on "defenders of science" to protect science from the sophists who question them and she cites "global-warming skepticism" as one example. This is a common refrain from those who favor particular government policies (Ceccarelli is a professor of communications, not a scientist), arguing that anyone who disagrees with them is ignoring the science.

Three things come to mind.

First, science does not dictate policy. Policy is set by weighing our value priorities and understanding the economic incentives used to achieve particular ends. Science informs the goals but often does not determine the tactics. For instance, if we agree with Ms. Ceccarelli that climate change is a concern, does science say a carbon tax or cap-and-trade is better? It doesn't. Sometimes, however, those who preach the primacy of science pretend it does. I wrote about this in February.

Second, in recent years it has been the left preaching the manta of "following the science," but their desire to do so is selective. Follow the science, they say, when it comes to climate change but not when it comes to DDT or preservatives in vaccines. With DDT and Thimerosal, a vaccine preservative, recent studies have shown definitively that there is little threat from the chemicals used to fight malaria or reduce the cost of vaccines, but in both cases the environmental community continues to ignore that science in favor of sophistry. The environmental community often cites theoretical science but ignores the empircal science ("worldwide temperatures haven't increased in a decade, but the models say they should").

Finally, if you want to see anti-scientific sophistry at work, watch this video of a recent effort to ban another dangerous chemical: dihydrogen monoxide.