rb1957, firstly, I think that I should acknowledge that you aren’t purporting a conscious suppression of “proper science” but mere “confirmation bias”, as made clear in your last paragraph.
You say, we agree to disagree but I’m unsure of where your disagreement comes in and whether our disagreement matters to the main point, which is -
how and why does this matter to climate science today?. I’d like to go through a couple possible objections that could arise from MM05 (and the rest of the “hockey stick” saga). Please let me know which objection(s) you agree with and how and why it matters to climate science today. If I haven’t exactly captured the wording of your objection, please feel free to correct and elaborate.
1) MM05 and the “hockey stick” topic makes you question the character of Michael Mann
From what I’ve read, Mann is arrogant and cocky. Many scientists, that agree with the science on climate change, say that had Mann simply acknowledged the technical issues in the first place, no one would be talking about it today. It was his aggressive defense (or attacking of his attackers) that made it seem like he was “hiding something”. Had he simply went “ya, there’s some issues. We’ve corrected them and still get the exact same conclusion.” (which
Wahl and Ammann 2007 did) people would have moved on. A great piece on the entire “hockey stick” issue can
be found here. I’d highly recommend reading it as it’s a fun read and relatively unbiased.
So if you question the character of Mann, I’d hardly oppose that view. However, the main question is, so what?
Impact on climate science today
None. If Mann is a questionable character or not, it means absolutely nothing to modern climate science. Mann is not the only one studying paleoclimate nor is he the sole voice of the paleoclimate community. Disregarding all of his papers, you’d still have the same main conclusions in the paleoclimate science and climate science in general.
Questioning the character of a scientists does not allow one to conclude that all the science is questionable. Doing so highlights a sever lack of comprehension on just how robust and diverse the evidence supporting climate change science really is. Seriously, it’s nuts. Go to the references in any chapter of any IPCC report and look at how many different scientific papers, from different authors from different institutions and journals, are referenced. To accuse all of them (them being scientists, institutions, journals and reviewers) of having the same “confirmation bias” is difficult to believe (especially with nothing but a hunch and a few anecdotal examples to support it).
2) To you, MM05 demonstrates that MBH98 is fundamentally flawed
MM05 points out some issue that are technically correct. Other issues raised by MM05 are due to an incorrect analysis/assumptions done by MM05.
Huybers 2005,
Wahl and Ammann 2007 and
Rutherford 2005 demonstrate this.
Taking into account the issues raised by MM05, what impact does that have on the conclusions of MBH98? Does it completely nullify the main conclusion (that the extent and rate of warming in the late 20th century is anomalous)?
No, it does not. Apply the “corrections” suggested in MM05 and here’s what you get (from Wahl and Ammann 2007, Figure 2.):
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Impact on climate science today
Seeing as MM05 really doesn’t change the conclusion of MBH98, it could hardly have any impact on climate science today. But let’s forget that for a minute. Let’s assume (incorrectly) that MM05 does demonstrate that MBH98 is fundamentally flawed, then what?
Still nothing. MBH98 is not the sole paleoclimate reconstruction. Again, I’d encourage you to visit NOAA’s Paleoclimate Network (PCN) which contains 92 temperature records. Or have a look through the
“List of large-scale temperature reconstructions of the last 2,000 years” Wikipedia page (which contains links to the (30+) specific papers). Or the
PAGES 2K Consortium (and
FAQ).
3) …But all those studies were based off MBH98. So, if MBH98 is wrong, they all are wrong
This thought is false on pretty well all accounts. Firstly, MBH98 is not fundamentally wrong. As shown, if you incorporate the criticisms of MM05, the late 20th century (and early 21st century) is still warmer than any other period in the reconstruction. Secondly, the subsequent studies use different (and increasingly better and more robust) data sets and use a variety of different techniques (some don’t use PCA at all). This is demonstrated in
Rutherford et al 2004 (Mann was a co-author). They conclude “These
evaluations suggest that differing methods of reconstruction (e.g., different CFR techniques or local calibration approaches) yield nearly indistinguishable results if differences in underlying proxy network, target season, and target region are controlled for.” Furthermore, they state, “Finally, the evidence for exceptional late-twentieth century warmth in the context of the period since A.D. 1400 (in warm, cold, and annual temperatures) is a robust conclusion with respect to all of the factors considered.”
If you don’t like that Mann was a co-author, then look at the
PAGES 2K information. They examine a much wider range (and more updated) data sets and techniques and specifically state “On the basis of our current assessment, about 360 of our 511 records were not used in the reconstruction of Mann et al. (2008, 2009)” and Mann was not an author of the Consortium (neither was Bradley, Hughes, Ammann, Rutherford nor Jones for that matter).
It should also be noted that many of the techniques, such as “climate field reconstruction” (CFR) methods, do not utilize techniques that were criticized in Von Storch et al 2004 (VS04) or Burger and Cubasch 2005 (BC05)/Burger et al 2006 (BFC06). Despite VS04 being criticized (and subsequently GC05 and BFC06, which are based off VS04) by such papers as
Wahl et al 2006, these papers are irrelevant to most paleoclimate reconstructions because they use different techniques than criticized by VS04, BC05 and BFC06. Again, the criticism of some possible techniques for reconstructions is not evidence (in the slightest) to suggest that all reconstructions are flawed.
So not only does it appear incorrect to conclude that MBH98 is fundamentally flawed but, even if we were to conclude that, it would be meaningless as the subsequent papers and reconstructions, from different authors, using different data sets and different techniques, all broadly agree with the same conclusion. To quote PAGES 2K,
PAGES 2K Consortium said:
The 20th century ranked as the warmest or nearly the warmest century in all regions except Antarctica. During the last 30-year period in the reconstructions (1971-2000 CE), the average reconstructed temperature among all of the regions was likely higher than anytime in nearly 1400 years. However, some regions experienced 30-year intervals that were warmer than 1971-2000. In Europe, for example, the average temperature between 21 and 80 CE was warmer than during 1971-2000.
In light of this, I’m unsure what parts you disagree with and why you do. I feel that you’ve read some things that sound convincing (or damning) but, in the broader context, those arguments just don’t hold up. If you want to hold a different opinion than that I’ve PAGES 2K, your going against the entire field of paleoclimatology. And you’d do this with no leg to stand on because even if you want to throw away all of Mann’s work and embrace MM05 as truth, it doesn’t change the conclusion in the slightest.
So, rb1957, I don’t believe it’s good enough to say we’ll agree to disagree. You simply cannot discuss this in isolation of MBH98 or Michael Mann in general.
Either we agree, and I misunderstand your position, or you disagree with the entire field of paleoclimatology and, I’m afraid to say, reject all the papers, research and data.
