Rearranging The Deckchairs

Frank O'Dwyer's blog

Mann 8, Shollenberger 0

March 11: 4 more here

Following on from my previous post, here’s 4 more problems with Shollenberger’s review.

6. Incorrect claim that the absence of an observation can’t support your position, while its inverse would say nothing

Shollenberger tries to base an accusation of contradiction on this:

If the existence of warming would say nothing, the lack of warming cannot say something. It makes no sense to say the absence of an observation supports your position, but the inverse would say nothing about your position.

This is easily dismissed by counterexample:

  • If oxygen is not present, there’s no fire.

  • If oxygen is present, there may or may not be fire.

That, to Shollenberger, should be ‘obviously contradictory’. It ‘makes no sense’.

Michael Mann: 5, Brandon Shollenberger: 0

7. Incorrect claim regarding tacit admission of ‘gatekeeping’

Shollenberger quotes Mann:

Some critics also claimed that the e-mails revealed a culture of “gatekeeping,” that climate scientists, myself included, were unfairly preventing skeptics from publishing in the peer reviewed literature. So claimed Patrick Michaels of the libertarian Cato Institute roughly a month after the CRU hack in a December 17 Wall Street Journal op-ed. Peer review, however, is by definition gatekeeping; it is intended to keep seriously deficient work from polluting the scientific literature.

And then says:

In response to he and his peers being accused of gatekeeping, unfairly preventing skeptics from publishing, Mann responds by simply saying peer review is inherently gatekeeping. He doesn’t dispute anything. He doesn’t deny skeptics were unfairly prevented from publishing. He defends against the accusation by tacitly admitting it is true.

You really don’t need to be a genius to understand that what Mann has ‘admitted’ to here is normal peer review. In order for Shollenberger to get his ‘tacit admission’, he needs to ignore the references Mann provided, because he also wrote, and referenced, this:

Patrick J. Michaels of the Cato Institute falsely claims that work by him (and other fossil-fuel-funded climate change contrarians) has been unfairly blocked by me and others from appearing in mainstream science journals because the peer review process is supposedly biased against climate science deniers.

In truth, the only bias that exists at such publications is for well-reasoned writing that is buttressed by facts.

That is why climate skeptics such as Richard Lindzen of MIT or John Christy of the University of Alabama—who are widely regarded as credible and whose work contributes meaningfully to the scientific discourse—have no problem publishing their work in mainstream scientific journals.

“Patrick J. Michaels…falsely claims” doesn’t sound like a tacit admission to me.

It is odd indeed that Shollenberger can find Mann’s references when he wants to claim they contradict Mann’s case, but can’t find them when they contradict his own.

It is also hugely hypocritical for ‘sceptics’ to clutch their pearls and head for the fainting couch whenever some substandard work is not published in a respected journal—especially when it is subsequently published elsewhere—all the while ignoring or encouraging extremely clear and vicious attempts to silence and intimidate working scientists who show that man-made global warming is happening.

If you have praised such attempts with faint damn, then you cannot be taken seriously, and nor can your deafening claims of being ‘silenced’.

Michael Mann: 6, Brandon Shollenberger: 0

8. Incorrect claim regarding ocean warming and UHI

Shollenberger has some more reading difficulties regarding ocean warming and UHI, where he takes another of his army of strawmen for a twirl around the dancefloor. Here he is quoting Mann:

There were even more basic reasons for rejecting the claim that the surface temperature record was compromised by urban heat island effects. The global warming trend is seen not only in land measurements but also in ocean surface temperatures, where obviously no urbanization is occurring. The ocean warming isn’t as large as the observed land warming, but this is expected from basic physics and predicted by all climate models

and then he says:

Mann says people should believe there is no warming bias in the land record because warming is also observed in the oceans. This claim isn’t based upon a comparison of the magnitude of trends. It just says both trends are positive, therefore there is no warming bias in the one. That makes no sense.

This is just a strawman. Mann is clearly talking about the surface record not being compromised, not the land record. He’s simply pointing out the obvious, that the surface also includes ocean and there cannot be UHI there. Nowhere does Mann say there is no warming bias (just that it is insignificant).

In order to pretend there is no quantification, in an argument which was never made, Shollenberger needs to (again) ignore Mann’s references, this time to IPCC AR4 which does quantify:

Urban heat island effects are real but local, and have not biased the large-scale trends. A number of recent studies indicate that effects of urbanisation and land use change on the land-based temperature record are negligible (0.006ºC per decade) as far as hemispheric- and continental-scale averages are concerned because the very real but local effects are avoided or accounted for in the data sets used. In any case, they are not present in the SST component of the record.

Accordingly, this assessment adds the same level of urban warming uncertainty as in the TAR: 0.006°C per decade since 1900 for land, and 0.002°C per decade since 1900 for blended land with ocean, as ocean UHI is zero. These uncertainties are added to the cool side of the estimated temperatures and trends, as explained by Brohan et al. (2006), so that the error bars in Section 3.2.2.4, Figures 3.6 and 3.7 and FAQ 3.1, Figure 1 are slightly asymmetric. The statistical significances of the trends in Table 3.2 and Section 3.2.2.4, Table 3.3 take account of this asymmetry.

Michael Mann: 7, Brandon Shollenberger: 0

9. Incorrect claim of contradiction regarding McIntyre and McKitrick ‘alternative reconstruction’

Shollenberger quotes Mann

Mann approvingly quotes Crowley criticizing McIntyre for not publishing an “alternative reconstruction” despite the fact 53 pages earlier, he claims McIntyre published an “alternative reconstruction.”

This is more reading comprehension failure from Shollenberger. What Mann actually wrote, and Shollenberger also quoted was this (my emphasis):

Paleoclimatologist Tom Crowley perhaps summarized it best: “McIntyre … never publishes an alternative reconstruction that he thinks is better … because that involves taking a risk of him being criticized. He just nitpicks others. I don’t know of anyone else in science who … fails to do something constructive himself.”

Key phrase: that he thinks is better. And that’s true, McIntyre has never published a reconstruction that he thinks is better, i.e. never one he would stand behind as representing our best guess at past temperature. (You would think he would have a go at giving an actual answer, if he likes puzzles so much.)

He has however published an alternative reconstruction that he didn’t think was better. This is from MM03:

Without endorsing the MBH98 methodology or choice of source data, we were able to apply the MBH98 methodology to a database with improved quality control and found that their own method, carefully applied to their own intended source data, yielded a Northern Hemisphere temperature index in which the late 20th century is unexceptional compared to the preceding centuries, displaying neither unusually high mean values nor variability.

While they clearly disavow it as saying anything about actual temperatures, in the paper and elsewhere, this index is the ‘alternative reconstruction’ being spoken of in Mann’s book (and in fact the use of the word ‘reconstruction’ comes from the Wahl and Ammam paper):

In MM03, a reconstruction for Northern Hemisphere mean surface temperature from 1400– 1980 is presented […] In MM05b, a second version of the MM reconstruction is presented that the authors describe as virtually identical to the one presented in MM03.

Michael Mann:8, Brandon Shollenberger:0