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When scientists become advocates, advocacy is presented as science. Here Judith Curry raises some serious questions about the 4th National Climate Assessment Report (NCA4).
National Climate Assessment: A crisis of epistemic overconfidence
Posted on January 2, 2019 by curryja | 15 comments
by Judith Curry
“You can say I don’t believe in gravity. But if you step off the cliff you are going down. So we can say I don’t believe climate is changing, but it is based on science.” – Katherine Hayhoe, co-author of the 4th National Climate Assessment Report.
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". . . I am fairly familiar with half of these scientists (a few of them I have a great deal of respect for), somewhat familiar with another 25%, and unfamiliar with the rest. I looked these up to see which of them were the paleoclimate experts. There are only two authors (Kopp and LeGrande) that appear to have any expertise in paleoclimate, albeit on topics that don’t directly relate to the Key Finding. This is in contrast to an entire chapter in the IPCC AR5 being devoted to paleoclimate, with substantial expertise among the authors.
A pretty big lapse, not having an expert on your author team related to one of 6 key findings. This isn’t to say that a non-expert can’t do a good job of assessing this topic with a sufficient level of effort. However the level of effort here didn’t seem to extend to reading the IPCC AR5 Chapter 5, particularly section 5.3.5.2.
Why wasn’t this caught by the reviewers? The NCA4 advertises an extensive in house and external review process, including the National Academies.
I took some heat for my Report On Sea Level Rise and Climate Change, since it had only a single author and wasn’t peer reviewed. Well, the NCA provides a good example of how multiple authors and peer review is no panacea for providing a useful assessment report. . . .
The most disturbing point here is that overconfidence seems to ‘pay’ in terms of influence of an individual in political debates about science. There doesn’t seem to be much downside for the individuals/groups to eventually being proven wrong. So scientific overconfidence seems to be a victimless crime, with the only ‘victim’ being science itself and then the public who has to live with inappropriate decisions based on this overconfident information
So what are the implications of all this for understanding overconfidence in the IPCC and particularly the NCA? Cognitive biases in the context of an institutionalized consensus building process have arguably resulted in the consensus becoming increasingly confirmed in a self-reinforcing way, with ever growing confidence. The ‘merchants of doubt’ meme has motivated activist scientists (as well as the institutions that support and assess climate science) to downplay uncertainty and overhype confidence in the interests of motivating action on mitigation. . . ."
National Climate Assessment: A crisis of epistemic overconfidence
Posted on January 2, 2019 by curryja | 15 comments
by Judith Curry
“You can say I don’t believe in gravity. But if you step off the cliff you are going down. So we can say I don’t believe climate is changing, but it is based on science.” – Katherine Hayhoe, co-author of the 4th National Climate Assessment Report.
Continue reading →
". . . I am fairly familiar with half of these scientists (a few of them I have a great deal of respect for), somewhat familiar with another 25%, and unfamiliar with the rest. I looked these up to see which of them were the paleoclimate experts. There are only two authors (Kopp and LeGrande) that appear to have any expertise in paleoclimate, albeit on topics that don’t directly relate to the Key Finding. This is in contrast to an entire chapter in the IPCC AR5 being devoted to paleoclimate, with substantial expertise among the authors.
A pretty big lapse, not having an expert on your author team related to one of 6 key findings. This isn’t to say that a non-expert can’t do a good job of assessing this topic with a sufficient level of effort. However the level of effort here didn’t seem to extend to reading the IPCC AR5 Chapter 5, particularly section 5.3.5.2.
Why wasn’t this caught by the reviewers? The NCA4 advertises an extensive in house and external review process, including the National Academies.
I took some heat for my Report On Sea Level Rise and Climate Change, since it had only a single author and wasn’t peer reviewed. Well, the NCA provides a good example of how multiple authors and peer review is no panacea for providing a useful assessment report. . . .
The most disturbing point here is that overconfidence seems to ‘pay’ in terms of influence of an individual in political debates about science. There doesn’t seem to be much downside for the individuals/groups to eventually being proven wrong. So scientific overconfidence seems to be a victimless crime, with the only ‘victim’ being science itself and then the public who has to live with inappropriate decisions based on this overconfident information
So what are the implications of all this for understanding overconfidence in the IPCC and particularly the NCA? Cognitive biases in the context of an institutionalized consensus building process have arguably resulted in the consensus becoming increasingly confirmed in a self-reinforcing way, with ever growing confidence. The ‘merchants of doubt’ meme has motivated activist scientists (as well as the institutions that support and assess climate science) to downplay uncertainty and overhype confidence in the interests of motivating action on mitigation. . . ."
