Thoughts from Judith Curry:

Yesterday, a reporter asked me how the IPCC came up with the 95% number. Here is the exchange that I had with him:

Reporter: I’m hoping you can answer a question about the upcoming IPCC report. When the report states that scientists are “95 percent certain” that human activities are largely to cause for global warming, what does that mean? How is 95 percent calculated? What is the basis for it? And if the certainty rate has risen from 90 n 2007 to 95 percent now, does that mean that the likelihood of something is greater? Or that scientists are just more certain? And is there a difference?

JC: The 95% is basically expert judgment, it is a negotiated figure among the authors. The increase from 90-95% means that they are more certain. How they can justify this is beyond me.

Reporter: You mean they sit around and say, “How certain are you?” ”Oh, I feel about 95 percent certain. Michael over there at Penn State feels a little more certain. And Judy at Georgia Tech feels a little less. So, yeah, overall I’d say we’re about 95 percent certain.” Please tell me it’s more rigorous than that.

JC: Well I wasn’t in the room, but last report they said 90%, and perhaps they felt it was appropriate or politic that they show progress and up it to 95%.

Reporter: So it really is as subjective as that?

JC: As far as I know, this is what goes on. All this has never been documented.

JC conclusion: Well, I have no idea what goes on in the sausage factory. 95% – take it with a grain of salt (or a stiff whiskey). That’s their story, and they’re sticking to it. Uncertain T. Monster is not happy.

I don’t know what this is, but sure as hell isn’t science.

[Update a while later]

A round up of initial reactions, for policy makers.

The general theme of obscurantism runs across the document. Whereas in previous years the temperature records have been shown unadulterated, now we have presentation of a single figure for each decade; surely an attempt to mislead rather than inform. And the pause is only addressed with handwaving arguments and vague allusions to ocean heat.

It was a blown opportunity to set the record straight.

[Update a few minutes later]

From comments: “SPM in a nutshell: Since we started in 1990 we were right about the Arctic, wrong about the Antarctic, wrong about the tropical troposphere, wrong about the surface, wrong about hurricanes, wrong about the Himalayas, wrong about sensitivity, clueless on clouds and useless on regional trends. And on that basis we’re 95% confident we’re right.”

[Bumped]

On the eve of the official release of the latest report, Steve McIntyre has some thoughts.

This is indeed disturbing:

German ministries insist that it is important not to detract from the effectiveness of climate change warnings by discussing the past 15 years’ lack of global warming. Doing so, they say, would result in a loss of the support necessary for pursuing rigorous climate policies.

Yes, we can’t let empirical reality get in the way of our policy agenda.

[Update a while later]

Desperate times in climate alarmism:

Confronted with all this truly disastrous news on the eve of their upcoming global warming summit, IPCC politicians, bureaucrats and eco-activists are trying to figure out how to cover up the bad news. Germany wants all references to the absence of warming deleted from the IPCC report. Whereas 20 years of mild warming were enough to demand immediate drastic action to avoid a climate cataclysm, now the Germans say 17 years of no warming is “too short” and thus “misleading.”

Hungary doesn’t want the IPCC to give “deniers” more ammunition. Belgium wants the “world’s most authoritative climate body” to manipulate the data and graphs, by using a different starting year that cleverly creates a more noticeable upward temperature trend. The Obama Administration wants the IPCC to explain away the absence of warming, by saying the mysteriously missing atmospheric heat was somehow absorbed by the upper 1.2 miles of oceans waters, which have not actually warmed, according to ARGO project data, or perhaps somehow in the really deep ocean, where we have no data.

In other words, if the models and evidence disagree, the evidence must be wrong. The IPCC is infallible.

Need I remind? This is not science.