Monday, March 15, 2010

Interview in Discover Magazine: Judith Curry vs Michael Mann

Interviews can be found here

I found both interviews interesting, and much can be learned about different mindsets. Judith Curry is being, surprisingly  for me, quite critical to the IPCC,   suggesting a stronger role of natural climate variations, and points to the influence of personality traits on the present stalemate; Michael Mann defends his points with passion, even flirting with the idea of a real danger for the human race.
Please, comment on the content of the interviews and avoid personal attacks.


@ReinerGrundmann said...

When Curry refers to a rise and fall in temperatures in the 1930s and ’40s that might have been caused by a coincidence of these oscillations in the Atlantic and Pacific, and another that could account for a lot of the warming in the 1990s. the question was put to Mann if that was a valid critique. He replies:
"The way you characterize it, it sounds like nonsense. I’m not sure how much familiarity she has, for example, with time-series smoothing."

I wonder what our experts here on the blog have to say. To me it sounds like Mann is trying to patronize her as not understanding the issue at all (only he does). At least this is the way he continues:
"I’ve published a number of papers on this topic, and in fact, the approach that I take was used in the most recent IPCC report. I actually take a very objective approach to the problem of time-series smoothing. I’m not sure she understands the problem. It is very much the mainstream view in the climate research community that you cannot explain the warming of the past few decades without anthropogenic and human influences on climate."

But Curry has not denied the human influences at all. She points to possible explanations for some anomalies. Or do I miss something?

Anonymous said...


If there were a danger for the human race, we would notice it in the next few years, I guess.

This is exactly what I call "Klimakatastrophist" (in german).

It sounds like Greenpeace not like science.

But, isn't also the flue a danger for mankind, BSE, "Feinstaub", tobacco, meteorites, asbestos, genetic engineering, Peakoil and last but not least the actual global economy crisis.

And what about demography, the pill, the pope? ;-)

Nono, I don't laugh. I'm very very afraid.

I like Miss Curry's point of view. But maybe she is wrong, maybe he is wrong ...

I would like to know your point of view, Mr Von Storch and Mr Zorita, pllllease ;-)

Best regards


Rob Maris said...

After reading both articles, I sympathize a bit with Curry. There's another unlucky point with Mann's sayings: Mentioning emails from Curry that she'd not want to be made public. Either one says such things in general terms, as in the sentences before, or you let it be. The reader could suggest: Ah, what's up with that? And he cannot answer (not because there is nothing, it's simply because of normal policy).

Generally I think that one cause of getting bigger discrepancy between science and public is continuous stressing of AGW in the public during the past 10 years without noting that we also had some coincidence of any long-term cycles in the nineties - and, as a consequence - the abiltity to also predict cooling influences after this bump.
But, when I'm informed well, "science" has been able to characterize multidecadal oscillations just quite recently (few years ago?). Nevertheless: In order to keep credibility, I do not get rid of the idea that these long-term oscillations haven't been a relevant issue as not to "unnessarily" disturb the Copenhagen process. For the case that this applies: I can understand that. I'm sure: when I'd have my profession in climate science and when I'm convinced about dangers coming soon or later - while knowing about enormous difficulties of steering a tall ship (politics) in a corrected direction, I'd not disturb the process with certain "less relevant" new information.

Applied to the long-term oscillations:
With today's knowledge, we can say that earlier openness about new findings woudn't impact IPCC's credibility as is actually the case. Then IPCC could point out with continuing credibility that despite all, a "linear" warming trend is still going on and be still potentially very impactive.

_Flin_ said...

I think when Mann is flat out asked about "our demise as a species", he answers quite reasonably. That if there is a growing environmental threat and there will be institutions who try to counter actions agains that threat, because that is how our system work. And that is true. And he says he is scared when asked about worst-case scenarios. Don't know how it is with you folks, but I am scared shitless when thinking about worst case scenarios. Like East Antarctica Ice Shelf disintegrating.

I personally liked this statement about the lack of Copenhagen action: "I try to approach this from a scientific point of view. My understanding of the science does lead me, personally, to believe that certain policy options are better than others. But the policy in no way influences my science, and I think that’s the way it should be."

Unknown said...

Curry mentions that uncertainty analysis is clearly a weakness in climate science but she blames that rather on sloppiness and imprecise language (use of "likely" or "very likely" instead of any quantitative confidence level or other statistical measure).

On IPCC she says, "The IPCC itself doesn’t recommend policies or whatever; they just do an assessment of the science [framed in UNFCCC]. It’s not a policy-free assessment of the science. That actually torques the science in certain directions, because a lot of people are doing research specifically targeted at issues of relevance to the IPCC. Scientists want to see their papers quoted in the IPCC report."
I appreciate that Curry realises that ther is obviously little inceptive to investigate e.g. the cause (PDO, AMO, more?) for the warm decade in the 1930s or the Medieval Climate Optimum (as it was formerly called) when apparently less CO2 was in the atmosphere.
But instead there might by a temptation or even a tendency to brush away those phenomena for they might cast doubt on the clean and tidy story that has been being told on global warming for ten years by now.

She also admits that scientists have been trying to convey a focused message for the IPCC report. She continues, "But that’s just not how science is. The scientists have gotten caught in these wars with the media and the skeptics. They spend so much energy trying to put them down, energy that isn’t going into uncertainty analysis and considering competing views. "
That's too simple an explanation. There are skeptical scientists around that have valid points of criticism. They should have been listened to instead of put down. Those skeptics (at least those to be taken seriously) were asking for more scrutiny and due diligence and statistical significance and error estimation and uncertainty analysis. All this is (scientific) skepticism (which Curry admits later on), it is a virtue of science!
"I don’t think the scientists have personal political agendas. I think it’s more hubris and professional ego."
I really, really hope for science's sake that Judith is right concerning the question of hubris and ego vs. political agenda.

She acknowledges that there are credible "scientific" skeptics around, but also "political" ones. This applies, by the way, to the AGW proponent camp as well.

Chapeau, Judith Curry! Although I can not agree with everything she says in this interview (and in her open letter to a bunch of climate blogs recently), she's on the right track and starts taking people outside acedemia seriously. I wish her all the best, because keeping a neutral point of view is hard, isn't it, Hans?

Unknown said...

Mann's perception of the CRU email incident is almost worth of being called a conspiracy theory.
His statement is so vague ("all sorts of organizations", "some people", "concerted effort", "larger campaign by special interests"), why doesn't he name names?
It is sad that he still downplays obvious flaws in CRU's work ("hide the decline") and continues claiming science being under attack. This is almost ridiculous because obviously the CRU Hockey team played their part in suppressing criticism and contrarian views.
The science is neither settled nor under attack. The science has been suppressed for years.

And (once again, sorry), the "Nature trick" is not "a clever mathematical approach" (quote) but a suppression of data and of an indication that something might be wrong with the proxies or at least needed to be investigated further. "And it’s extremely easy for those looking to make mischief to take single words and phrases out of context."
Put into the right context, the "single words and phrases" and the alleged "trick" is even worse.

Michael Mann instead seems to continue "circling the wagons" around the ivory tower of science being besieged by the "denial machine". He should rather think twice or stop giving interviews for quite a while not make things worse for him.
The science is unsettled. The debate is not over -- it has been liberated.

eduardo said...

@ 1

well, I think the interview reflects realistically the way Mann sees himself in a debate. I see nothing new here. I was however surprised by the openness of some of Judith Curry's answers, some of which I really agree with. For instance, that statistical methods are not always properly applied. This is understandable because many climatologist dont have a proper background in statistics and had to learn a lot from scratch- me included. This requires quite a lot of time and effort and the danger of making mistakes is not negligible.

I really dont see why the issue of time series smoothing is raised here, but perhaps I read the interviews to quickly.

Curry is addressing the uncertainties that we still have in explaining the 20th century climate. For instance, I think it is not clear at all what was the cause of the first phase of warming from 1910 until 1940 which has been attributed to 'internal variability'. Aerosols are also a source of uncertainty. Mann doesnt seem to like uncertainties, perhaps because he assume that this would dilute the message. Whether or not this is his reason, the strategy of brushing uncertainties aside has proven not very effective so far

ApolytonGP said...

Curry should join the onion. She actually writes papers and will call the truth whichever way it goes. She's better than McI (cherrypicked crits and doesn't ever write his critisms down properly...he's a mess). She's better than Mann...touchy little ego-scientist, who doesn't like people checking his work (remember "we won't give up the algorithm" for MBH98?)

P Gosselin said...

Judith's most damning statments in my view are:
1. "...Michael Mann’s behavior, trying to keep the data and all the information away from McIntyre, McKitrick, and other people who are skeptical of what they were doing."
2. "The IPCC took a shortcut on the actual scientific uncertainty analysis on a lot of the issues, particularly the temperature records."
3. "It’s sloppiness. It’s just how our field has evolved."
4. "My point is that at the end of the 1980s and in the ’90s, both of the ocean oscillations were chiming in together to give some extra warmth".
5. "McIntyre does not have a Ph.D. He does not have a university appointment. But he’s made an important contribution, starting with criticism of the hockey stick."

It really does appear that Ms Curry has grown rather appalled at the way her field has evolved, and Mann goes on to confirm why.
And I'm quite sure she's about to become even more appalled - soon.

Some people will never learn that you just can't go around turning colleagues into bitter enemies. Those who live by the sword, die by it.

P Gosselin said...

Thank you Georgia!

P Gosselin said...

Despite the "unprecedented" global warming and the threats to the human race it allegedly presents, the following study shows that mortality due to extreme weather events has declined dramatically since the 1920s.

plazamoyua said...

Call me naive, but I would say there are more points of agreement between the scientists so called "skeptics", and Curry (in this interview) and Eduardo (@ 7), than between JC - EZ, and Mann et al.

Rob Maris said...

@ P Gosselin
Presenting a link to a paper that apparently sources from a conservative group (AAPS) and - by the way also does not really relate to climatic issues (since mortality statistics are not an issue here) - is not very helpful. By the way, I'd much more trust e.g. Munich Re reports about catastrophe statistics, because it is one of their primary jobs.

Your Curry quotes are a typical example of skeptics cherry picking. Curry, as well as Hans and Richard Tol and others are sound "scientific skeptics" who all consider CO2-warming as fact.

Hans has undertaken patienceful efforts to try to keep this blog at a good level backed by his believe in man's reasonability.
In the case of Gosselin these efforts seem to fail, see also that "thank you Georgia!"

A final note: In my opinion Gosselin himselfs lives by the sword (too). I'll skip his postings from now on, surely after I found this Gosselin quote on the www: "Stefan-1.9 meter-Rahmstorf is full of it. In my view he is a complete charlatan who is wasting may tax money."

Anonymous said...


Those who have followed both the scientific and the popular discussions on climate probably knows what Mann is talking about. E.g.


isaacschumann said...

@Rob Maris,

I mostly agree with you, but you seem to be implying that we should put a special emphasis on the results from Munich Re. I disagree, they are a private insurance company whose economic interests are directly involved. I do not mean to disparage Munich Re, as they have a good reputation and much of their studies are published in peer reviewed journals, but I think that it is telling that their study claiming a statistical link between global warming and catastrophe losses was not.(I think... please correct if I am wrong) And much of the other independent literature on the subject did not agree with this claim.

Studies sponsored by industries with economic interests involved in the climate change debate such as oil, gas and coal companies, would be heavily criticized because of the obvious conflicts of interest. Munich Re would make a higher profit if future disaster losses from climate change were perceived to be higher as that would justify higher premiums now. Why is this so different that an opposite response is required? (to signal their work as having particular credibility as opposed to less)



Hans von Storch said...

Munich Re - the former head of the geo-risk group published in the 1990s at least two articles, in which he claims, or suggested that storms in our part of the world would presently become more frequent or severe probably as an effect of elevated greenhouse gases. These articles were not peer-reviewed, as far as I know, and his claim was later falsified. He still repeats his claims about present European storminess though he knows about the empirical counter arguments.

Rob Maris said...

isaacschumann: it was my primary intention to point out that I more trust e.g. Munich Re Reports (... their job ...) than reports by Physicians and Surgeons regarding the issue.
Indeed, Munich Re is a sort of stakeholder as is recalled here. Thanks for sharpening my attitude where it concerns any bias or prejudice of reports.