By S. Fred Singer
Gallia omnia est divisa in partes tres. This phrase from Julius Gaius Caesar about the division of Gaul nicely illustrates the universe of climate scientists — also divided into three parts. On the one side are the “warmistas,” with fixed views about apocalyptic man-made global warming; at the other extreme are the “deniers.” Somewhere in the middle are climate skeptics.
In principle, every true scientist must be a skeptic. That’s how we’re trained; we question experiments, and we question theories. We try to repeat or independently derive what we read in publications — just to make sure that no mistakes have been made.
In my view, warmistas and deniers are very similar in some respects — at least their extremists are.
They have fixed ideas about climate, its change, and its cause. They both ignore “inconvenient truths” and select data and facts that support their preconceived views. Many of them are also quite intolerant and unwilling to discuss or debate these views — and quite willing to think the worst of their opponents.
Of course, these three categories do not have sharp boundaries; there are gradations. For example, many skeptics go along with the general conclusion of the warmistas but simply claim that the human contribution is not as large as indicated by climate models. But at the same time, they join with deniers in opposing drastic efforts to mitigate greenhouse (GH) gas emissions.
I am going to resist the temptation to name names. But everyone working in the field knows who is a warmista, skeptic, or denier. The warmistas, generally speaking, populate the U.N.’s IPCC (Intergovernmental Panel on Climate Change) and subscribe to its conclusion that most of the temperature increase of the last century is due to carbon-dioxide emissions produced by the use of fossil fuels. At any rate, this is the conclusion of the most recent IPCC report, the fourth in a series, published in 2007. Since I am an Expert Reviewer of IPCC, I’ve had an opportunity to review part of the 5th Assessment Report, due in 2013. Without revealing deep secrets, I can say that the AR5 uses essentially the same argument and evidence as AR4 — so let me discuss this “evidence” in some detail.