[Originally posted 3/19/2007]
One of the latest ways to get a media headline is to claim that global warming is a scam. TV specials, books, and many blogs thrive on raising doubts of the scientific claims of global warming.
Far be it from me to settle those debates. I do find it interesting, however, that the louder the controversy swirls, the more emphatic is the response that there is no controversy! How is it possible that such a controversial topic doesn't have any controversy?
The answer, I think, lies in the community of people we are talking about as well as the time frame. The technical community of scientific professionals, namely the climatologists, glaciologists, oceanographers, botanists, etc. are the ones who make a living studying these matters. Back in the 70's and 80's there was very little consensus and very few if any credible models about global climate within this community. Suggestions of global warming were met with a lot of professional skepticism. But as the database grew and more and more publications came out based on a variety of independent models, the community as a whole eventually came to recognize the overall trend, even though a myriad of details need to be worked out. It seems accurate to say that there is no controversy within that community. That's not to say there isn't the occasional publication raising questions but none has been independently corroborated as nullifying the basic concept of global warming.
On the other hand, the controversy is raging more loudly than ever outside the technical community. Many an "expert" with just enough knowledge to be dangerous has raised a dissenting technical point, sometimes through a TV special or sometimes in a book or novel, or perhaps just on a blog. Here the controversy is very real indeed. To be taken seriously, these points need to be scrutinized, peer-reviewed, and independently verified by the professional community. If the claims don't survive that process, they shouldn't be perpetuated.
Scientists aren't always right. But the methodical approach of science slowly but surely is self-correcting and the right perspective ultimately survives. For scientific observations to be used as a basis for policy, they must survive the tough standards of peer review and independent verification. That's necessary, though not sufficient, to justify action.