Thursday, 7 December 2017

CLIMATE DEBATE SHOWS UP THE UNCERTAINTY

Here is a very interesting, (though rather lengthy) discussion between six expert scientists, three sceptics (John Christy, Richard Lindzen and Judith Curry) and three alarmists (Ben Santer, Isaac Held and William Collins). It could be a foretaste of the red/blue debates that are coming soon. I found it very revealing as it shows that, in private at least, the alarmists show themselves to be much less certain of their position than is the case in public.

This paragraph sets the scene: "The 2014 APS Climate Workshop: A Perfect Venue for Open Debate. Things are different when climate scientists are on the stand alongside their peers who know the science as well as they do, but disagree with the conclusions they draw from the same body of knowledge. Such open debate was on display at the 2014 American Physical Society (APS) climate workshop, which took place in Brooklyn and lasted just over seven hours. A unique event in the annals of the climate debate, it featured three climate scientists who support the climate change consensus and three climate scientists who do not. That format required an unusual degree of honesty about the limitations of the current understanding of the climate system. For the most part, circumspection, qualification, and candid admissions of lack of knowledge were the order of the day. Drawing extensively from the 573-page transcript of the APS climate workshop, this paper examines the gap between how climate scientists debate with each other and how they speak to the media and the wider public".

And here's an extract of one very pertinent exchange: " Steven Koonin, chairing the APS workshop, read an extract from chapter 10 of the IPCC’s Fifth Assessment Report. Model-simulated responses to forcings—including greenhouse gas forcings—“can be scaled up or down.” To match observations, some of the forcings in some of the models had to be scaled down. But when it came to making the centennial projections, the scaling factors were removed, probably resulting in a 25 to 30 percent over-projection of the 2100 warming, Koonin said. Only the transcript does full justice to the exchange that followed.

Dr. Koonin: But if the model tells you that you got the response to the forcing wrong by 30 percent, you should use that same 30 percent factor when you project out a century. Dr. Collins: Yes. And one of the reasons we are not doing that is we are not using the models as [a] statistical projection tool. Dr. Koonin: What are you using them as? Dr. Collins: Well, we took exactly the same models that got the forcing wrong and which got sort of the projections wrong up to 2100. Dr. Koonin: So, why do we even show centennial-scale projections? Dr. Collins: Well, I mean, it is part of the [IPCC] assessment process.

“It is part of the assessment process” is not a scientific justification for using assumptions that are known to be empirically wrong to produce projections that help drive the political narrative of a planet spinning toward a climate catastrophe. [you just could not make this up!]

John Christy’s Congressional Testimony. In 2017, Christy took his analysis of the model prediction of a tropical tropospherical hot spot to the House Science, Space, and Technology Committee. “To test this result we follow the traditional scientific method in which a claim (hypothesis) is made and then is tested against independent information to see if the claim can be sustained or whether it is falsified,” Christy told the committee.  Comparing model trends with the actual 38-year trend, the models failed to represent real world observations by “a highly significant amount.”  The IPCC had these results in time for inclusion in chapter 10 of the IPCC Fifth Assessment Report. What to do with them? The inconvenient findings were relegated to an annex of supplementary material and fashioned into charts that are hard to understand, Christy told the committee. They show model trends in which extra greenhouse gases are included lying completely outside the range of the observational trends, indicating that the GCMs, as hypotheses, failed a simple scientific-method test. It is hard to argue with Christy’s conclusion: “That this information was not clearly and openly presented in the IPCC is evidence of a political process.” The IPCC then went on to increase its confidence in asserting that humans were causing the majority of climate change based on those very same models.


Do read it all at the above link and see just how much doubt and uncertainty is expressed by those alarmist scientists, who in public express no doubt whatsoever.  

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