Monday, December 15, 2014

Criticism of the IPCC from a Competent Source

I just came across an interesting piece online which quotes extensively from testimony by a prominent scientist critiquing the IPCC. It provides a good rebuttal to those who imagine that the only critics are ignorant and/or venal people who believe in a vast conspiracy of climate scientists. 

Testimony by Daniel Botkin


Josiah Neeley said...

It may be a good rebuttal to those who imagine that the only critics are ignorant and/or venal people who believe in a vast conspiracy of climate scientists, but I'm not sure it's a good rebuttal to anyone else. It seemed nitpicky and all over the place, IMO.

Ricardo Cruz said...

Hmm, I never questioned the IPCC, but his accusations if true put the IPCC credibility in question for me. Does anyone know if this point of his is true? It should be possible to verify ...

14. Some of the reports conclusions are the opposite of those given in articles cited in defense of those conclusions.
For example, the IPCC 2014 Terrestrial Ecosystem Report states that “there is medium confidence that rapid change in the Arctic is affecting its animals. For example, seven of 19 subpopulations of the polar bear are declining in number” citing in support of this an article by Vongraven and Richardson, 2011. That report states the contrary, that the “‘decline’ is an illusion.

In addition, I have sought the available counts of the 19 subpopulations. Of these, only three have been counted twice; the rest have been counted once. Thus no rate of changes in the populations can be determined. The first count was done 1986 for one subpopulation.

Ricardo Cruz said...
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Ricardo Cruz said...

Considering [Vongraven and Richardson, 2011], I don't understand why Daniel Botkin says the article says the decline is an "illusion". The IPCC does seem to imply more than what the authors of the article state though.

Josiah Neeley said...


I had the same reaction as you. The V&R article doesn't seem to say what Botkin says it does, which given that it's an example Botkin picked of IPCC inaccuracy is kind of odd.

Daublin said...

Good cite, David. I also like to cite Dyson as a rather respectable figure who is down on the IPCC.

He is kinder to the IPCC participants than I think they deserve. They're doing shoddy work because it generates eye-popping conclusions. That's exactly the opposite of how science is supposed to work. Scientists are supposed to be skeptical until evidence mounts; they're supposed to be open to interpretations to the greatest extent possible.

For the general public, I think these shenanigans are not the best focus, though, as David has often argued. Other things that are more salient are:

- CO2 controls as currently designed have no hope of actually lowering CO2. People who say this issue is so important: why not put forward a real proposal and a plausible way to get there?
- Modern industry is unknown in history and has enormously changed humanity for the better. We should protect it.
- The worst horror stories about CO2 increases are not as bad for humanity as, say, hunger or malaria. It's incredibly conservative to suggest we should keep the overall environment the way it is; where are the progressives on improving the environment?
- As David often writes, the worst horror stories are unlikely. Much more likely is that a warmer earth is a good thing.

Glen said...

Botkin might be complaining in part about the omission of the last clause in the abstract: "...with trends in two linked to reductions in sea ice." That's two out of 19. The IPCC text pretty clearly suggests that all 7 (of 19) "declines" are both well established and caused by climate change; the report they point to doesn't support them on this.

Richard Ober Hammer said...

I assume you are also aware of the statements made by of Judith Curry. She has a blog. Many links can be found. Here is an EconTalk
from a year ago.

Josiah Neeley said...


That might be a good criticism of the IPCC report, but it's not the one Botkin made. Botkin claimed the V&R study says the decline in polar bears itself is an illusion.

Ricardo Cruz said...

Glen, the article says 7 subpopulations are in decline, and 2 of those can be positively attributed to "a result of climate-mediated changes in the availability of sea ice". Therefore what Botkin quotes from the IPCC report is accurate. I do not know what more the IPCC report says. Anyhow, given that Botkin's "illusion" quote cannot be found in the article, I will not trust his quote of the IPCC.

Hyman said...

"Figure 1" is addressed here:

AGW denialism is rather like creationism; denialists are forever casting about for some single fact which they believe will doom the entire enterprise while ignoring the vast amount of science which supports it.

Libertarians and free-marketers seem particularly susceptible to AGW denialism, perhaps because they're unable to conceive of a global problem which must be addressed by the world as a whole rather than leaving it to local-level micro-optimization.

Anonymous said...

It's unfortunate that you're relying so heavily on Botkin.

There are some questions about his knowledge of the science and the nature of the relevancy of his work.

stan said...

If you would like to read an intelligent skeptical position, read RG Brown. He's a Duke physicist. Here --
"This is a hard problem. Not settled science, not well understood, not understood. There are theories and models (and as a theorist, I just love to tell stories) but there aren’t any particularly successful theories or models and there is a lot of competition between the stories (none of which agree with or predict the empirical data particularly well, at best agreeing with some gross features but not others). One part of the difficulty is that the Earth is a highly multivariate and chaotic driven/open system with complex nonlinear coupling between all of its many drivers, and with anything but a regular surface. If one tried to actually write “the” partial differential equation for the global climate system, it would be a set of coupled Navier-Stokes equations with unbelievably nasty nonlinear coupling terms — if one can actually include the physics of the water and carbon cycles in the N-S equations at all. It is, quite literally, the most difficult problem in mathematical physics we have ever attempted to solve or understand! Global Climate Models are children’s toys in comparison to the actual underlying complexity, especially when (as noted) the major drivers setting the baseline behavior are not well understood or quantitatively available."

See also the 6 part debate --

David Friedman said...

(Written years later when going over this material)

I checked the V&R piece on polar bears. On the one hand, they list seven populations as declining. But if you look at Table ME1, four of the seven are listed as trend "declining" but status "data deficient." Only three are listed as status "reduced."

I think that explains what Botkin said, but I don't understand the distinction the paper is making, in what sense it finds a declining trend with insufficient data.