Seven,
This guy has some credentials to comment in the area of man made climate change:
http://www.drroyspencer.com/2011/02/on-the-house-vote-to-defund-the-ipcc/
Worth the read. He seems to suggest the science is being twisted more on the IPCC side than any other:
Spencer's science needs to be separated from his views on things like the peer review process and the structure of climate organisations. He is a member of the Heartland Institute, and a contributor to the George C. Marshall Institute, which are both conservative leaning lobby group that have voiced ideological opposition to various officially funded scientific organisations.
In fact, much of Spencer's commentary could be seen to be coloured by his political ideology. He is a vocal proponent of the teaching of intelligent design alongside evolution in science classes, (which I find interestingly hypocritical considering his views on problems with the evidence for climate change - though he is entitled to his position), and has been a regular with various conservative media outlets (Rush Limbaugh has described him as the official climatologist of the Excellence in Broadcasting Network, which is a light-hearted organization he invokes to describe people who agree with him). Again these views are fine, but his comments need to be viewed accordingly - separating the science from the political opinion.
As for his statements about the IPCC; they are, in my opinion, problematic, but not unfounded. Again it is important to remember that much of his commentary here is as a think tank member, rather than as a university professor. In any case I am inclined to agree with at least some of his charges. The IPCC has made mistakes, the most memorable being the substitution of 2350 with 2035 in a report about the potential for catastrophic melting of the Himalayan glaciers, and there has been persistent criticism of aspects of the make up of the council, but the IPCC's review and publication system has been regularly subjected to independent investigation, most recently in September 2010, when the InterAcademy council report on the assessment process concluded that it was largely successful.
There is no doubt that the IPCC is influenced by external politics, and is subject to it's own set of internal divisions. Though it has been vetted by several independent groups, I would still describe their assessment process as flawed. It is even occasionally accused of being too conservative with it's predictions. None of these are criticisms that negate the quality of it's reports though, which must be approach with a balanced, critical, scientific eye.
It is also important to note that the IPCC is a review and advisory agency that undertakes no original research. Spencer can huff and puff about selective inclusion of research all he likes, at the end of the day he needs to engage the actual mechanism of climate change. Which brings us to the science.
Spencer's primary climate claim is to do with the problematic issue (in climate models, at least) of the effect of clouds in warming models. He used to make an argument about discrepancies between troposphere and surface temperature records, but that was quashed in 2005 when it turned out the data had been incorrectly collected (it wasn't he who collected it; the method had been faulty for years).
It's difficult to address his points here, as it would require a fairly extensive essay. I will say that;
Spencer is right about the difficulty in accounting for the effects of clouds in climate models. The evidence to support his assertion about cloud feedback are much more difficult to test. In his model he use a simplified box model - a uniform mixed ocean of ~50m in depth and standardized surface atmosphere. This is perfectly legitimate, and indeed is the norm in climate science.
He contends that the "alpha" values (the feedback in the system - it can be positive or negative, with positive numbers implying a stabilizing influence, and negative implying an acceleration of change) used by other scientists are wrong due to a faulty method of taking satellite readings, and in 2008 he submitted a paper for peer review that stated that the correct alpha value for clouds in his study was in the area of 6 W/m^2/°C, indicating very strong negative feedback in the short term. This inferred that increased cloud cover was actually having a causative effect on surface warming, rather than the other way around. The implication of this is that the planetary wide climate change we are currently recording can occur without human influence.
His alpha method reasoning is sound, but it has since been suggested that the overall figure is much closer to zero, and that his method produces a much less pronounced result if a more complex model is used, with ocean current and stratification taken into account. In addition some of his temperature predictions have not been supported by the evidence collected over the past 30 years.
Further studies about the southern oscillation index determined that it was difficult to verify Spencer's cause and effect hypotheses, and some have noted that with respect to El Nino, which Spencer has argued about vociferously, it would be seem that he is using a single figure from a previous study to justify his claims of a planet wide impact. Then in 2010, a further study suggested that Spencer had over estimated regression curves and oversimplified feedback mechanisms which had given him an inaccurate alpha reading, so though his mechanism for taking the alpha readings is sound, he was basing his assertions on a number that was inaccurate.
Finally, even he himself concedes that in long term feedback loops the value of alpha is probably close to 3.0 W/m^2/°C, which indicates a weakish positive feedback. Seeing as the predictive models, and indeed climate change itself, are long term, large scale events, this counters the view that clouds are having a causative effect on global warming.
There could be some mistakes in there... it's hard to proof read in this text box, and I am short of time atm.
