Monday, November 1, 2010

Climate Change Skeptics: Strictly Science

In a recent posting Rob Maris conducted a survey to determine what makes a climate change skeptic. It received both criticism and praise. Mention was made that skepticism might reside in the science-policy interface. I have chosen not to enter into the fray of policy as I believe science that shares a bed with politics has a tendency to lose its objectivity and, as history has repeatedly demonstrated, results in dogma. Consequently this discussion is limited to climate change skepticism in climate change science. Here I attempt, first, to forward the definition of climate change skeptic in climate change science. After all, outside of our area of expertise we are limited to expressing opinion, be that good or bad, it is the reality.  I then present a few empirical examples that add to the confusion.

At this point, a short discussion of ‘skeptic sans climate change’ is in order. First of all, being ‘skeptic’ presupposes a difference from something – a non-skeptic for want of better category. ‘Difference’ presupposes measurement or a differing (unique) quality of some nature. Unless we know what the something is that can be measured or the quality that differs there can be no significance in the difference. Both definition and measurement lead to relations which set entities apart – in this case skeptics and non-skeptics – in respect to one another. This seemed to be the goal of Rob Maris’ survey. (However, in a comment following his posting I noted, based on empirical data, that his definition, a number of definitions in fact, of ‘skeptic’, contained a number of weaknesses.

I’d like to focus a little here on what a definition is, or should be. Definition in general is concerned with the systematic ordering of categories or concepts and with the nature of relation between entities, creating a mutually exclusiveness, and addressing that which is unique. This is the first requirement in addressing skeptics versus non-skeptics. Measurement, on the other hand, if necessary for our discussion, should establish a metric order among different manifestations of particular properties – in this case, ‘how skeptic’ or what constitutes healthy and non-healthy scientific skepticism? After all, we need to make the distinction between healthy climate science skepticism and the complete disbelief in the climate change phenomenon, between belief in the IPCC consensus (which supposedly represents the climate science community) and those who disagree with the IPCC statements (and should this include those who say the IPCC underestimates things climate change, those making such claims are skeptical concerning the scientific consensus but not the phenomenon of climate change per se). So the first question is, skeptical of what? Climate change or consensus. There is also the question of skepticism and attribution: to anthropogenic or not to anthropogenic, that is the question.

To return to measurement, the function of measuring something is to set it in an order that addresses a class of events determined by the exhibition of certain properties, in our case, the degree of skepticism. So in our first encounter, the IPCC consensus, we have a skeptic - – non-skeptic – skeptic + scale, (too warm, just right, too cold – just for Richard) but what do we use for thresholds of skepticism? Anthropogenic – Natural attribution is a much easier distinction, an unambiguous relationship. Or is it? What of scientific uncertainty? Healthy scientific skepticism! But where is the threshold, at what point is the transition from skeptic to non-skeptic? These are relations of coincidence and precedence: more than, less than; smaller than, bigger than … . So how do we want to describe skepticism? What distinguishes healthy science skepticism from non-healthy scientific skepticism?

In fact, there are a number of concrete issues which could constitute questions pertaining to climate change skepticism. I have chosen 4 to represent some of the broader issues:

The causes of climate change.

The projections of climate models.

The consequences (impacts) of climate change.

The IPCC conclusions.

(Note, I have not asked ‘Is climate change dangerous?’ for example, as this evokes comments beyond the expertise of climate scientists.)

The concrete issues one by one.

For the following analysis, I use the results of the survey of climate scientists conducted by Bray and von Storch, noted on this blog and in the comments to Rob Maris’ posting.

The causes of climate change.

Here I only make 2 distinctions; anthropogenic or natural, and make the assumption that those who attribute climate change to natural causes, I label skeptics, not skeptical of he manifestation of climate change, but skeptical of the popular form of attribution. (I have not asked about the manifestation of climate change as not one respondent reported being fully convinced that climate change, whatever the cause, is NOT occurring. and only approximately 2% of respondents expressed significant doubt, whereas 67% expressed the maximum expression of certainty available on the questionnaire. Minimal doubt was expressed by another 27% (perhaps healthy scientific skepticism but definitely not an indication of disbelief in climate change). Back to attribution: About 85% of the respondents tend to think to some degree (more yes than no) that climate change could be attributed to anthropogenic causes. However, only about 35% expressed the maximum possible level of certainty. Does this mean that 65% should be labeled skeptics? Or should the 11% that tended towards favouring doubt be the ones to be labeled skeptics? Or should we have 11% skeptics, 55% healthy science skeptics and 35% non-skeptics? Which brings us back to definition and measurement.

The projections of climate models (limited to temperature only).

Scientists were asked ‘How well do global climate models model temperature values for the next 50 years? 6.54% said very poor and 2.45% said very good. On the healthy skepticism side then it could be claimed there are 91%, at the full skeptic level only 6.54%.

The consequences (impacts) of climate change.

I will pick only one variable here for simplicity’s sake: ‘If we do not do anything towards adaptation or mitigation, the potential for catastrophe resulting from climate change for the country in which you live in the next 50 years is? Looking at the two extremes, about 16% fall into the full skeptic camp and about 2% the non-skeptic camp, with the rest falling into healthy skepticism.

The IPCC conclusions.

While there are a number of applicable variables, I have chosen the responses to the statement ‘The IPCC reports accurately reflect the consensus of scientific thought pertaining to temperature. Here, only 17% strongly agreed (the non-skeptic) and only about 2% strongly disagreed, with about 80% expressing some doubt.

Now, if one is a true skeptic in the fullest senses, for each of the above questions he or she should have responded with a value of 1, expressing the maximal level of doubt about the dimensions of climate change in the questions. If we produce a count of persons answering 1 to the above (only 4) questions, the total count is 1 suggesting that of the 373 respondents to the survey, only 1 could be considered a total skeptic. On the other hand, if we limit the value to 7 – the total non-skeptic – the number of respondents is 0. Is there 1 or 373 skeptics?

What can we conclude from this? Skepticism among scientists is not ‘total’. Scientists might be skeptical about some things in science but not others, there are degrees of ‘scientific’ skepticism and this is a healthy state for science. So perhaps we could say the greatest extent of skepticism must concern appropriate policy, where climate scientists, if they indeed do, make value laden judgments the same as lay people.

So let’s get back to who is a climate change skeptic. First, we need to make a distinction between those who work in climate science and those who do not. To ask if they are a skeptic or not is too simple. To ask what made them skeptic without first determining if they are a skeptic (other than by self proclamation) is putting the cart before the horse. But in order to determine if one is a skeptic or not it is necessary to agree on a definition for ‘skeptic’, an appropriate scale of measurement of skepticism and the threshold at which change occurs from healthy to non-healthy scientific skepticism.

If I do not agree 100% with something, then I am skeptical. The question is: ‘How skeptical must I be before I am given the label of skeptic?’

29 comments:

Günter Heß said...

Dear Dennis,
you write:
“If I do not agree 100% with something, then I am skeptical. The question is: ‘How skeptical must I be before I am given the label of skeptic?”
Nobody should give a label to other people.
I have a question for you. In their book “Der Klimawandel” "Climate Change" in English. Rahmstorf and Schellnhuber write a chapter called: “The lobby of denier” “Die Lobby der Leugner” in German and label people who are sceptics for some aspects of the things you mentioned above denier. What is your opinion about that.
I think this is the real problem of the climate debate and the credibility of climate scientists. Labeling people skeptics is not the problem, it is the synonym usage of skeptics and deniers as political arguments that poses the problem.
Best regards
Guenter

aber said...

# Dennis Bray says: “Definition in general is concerned with the systematic ordering of categories or concepts and with the nature of relation between entities, creating a mutually exclusiveness, and addressing that which is unique”
Let me say it more simple: “A definition is a (mutual) mean to know what one is talking about.

Now, if one wants to analyse who is, or not is, a climate change skeptic requires a definition of “Climate Change”, and as Climate is defined a average (or statistical) weather, there needs to be a definition on Weather in the first place. A original definition on WEATHER does not exist. See my previous comments to the Klimazwiebel post “A quote provided by Mathis Hampel “ (Fri.29Oct2010). Who than can know what “climate change” means, and either be pro or contra in this respect?

The Glossary of the American Meteorological Society (AMS) says that weather is: “The state of the atmosphere, mainly with respect to its effects upon life and human activities”, AMS thereon breaks the weather down into:
___The “present weather” table consists of 100 possible conditions,
___with 10 possibilities for “past weather”, while
____Popularly, weather is thought of in terms of temperature, humidity, precipitation, cloudiness, visibility, and wind.
(In detail HERE at: http://www.whatisclimate.com/b206_need_to_talk_July_2010.html )

Discussing and categorising ‘pro’ and ‘contra’ actually requires to say precisely what physical conditions (or parameters) of the present, past, or future weather conditions one is talking about. Summarizing it under the meaningless term “climate change” causes serious confusion and misunderstanding. (see UNFCCC: Para. 2.: “Climate change” means a change of climate which....”). More at: http://www.whatisclimate.com/b202-open-letter.htm
Arnd Bernaerts

Alex Harvey said...

Hi Dennis,

You wrote,

"About 85% of the respondents tend to think to some degree (more yes than no) that climate change could be attributed to anthropogenic causes. However, only about 35% expressed the maximum possible level of certainty. Does this mean that 65% should be labeled skeptics? Or should the 11% that tended towards favouring doubt be the ones to be labeled skeptics? Or should we have 11% skeptics, 55% healthy science skeptics and 35% non-skeptics? Which brings us back to definition and measurement."

At face value, it sounds like 35% are believers, 55% are healthy skeptics and another 11% are hard core skeptics.

But: if 66% of scientists are somewhat or completely skeptical, what does this say about a result like the Oreskes 2004 study that purportedly showed that of 928 randomly selected scientific research papers, "Remarkably, none of the papers disagreed with the consensus position" (i.e. the 'consensus' on anthropogenic attribution).

http://www.sciencemag.org/cgi/content/full/306/5702/1686

How can these two results be reconciled? 65% of scientists are privately somewhat or very skeptical, yet none of them are publishing papers to argue against anthropogenic attribution.

Isn't this a pretty good argument in itself that, for whatever reason, it is very difficult to publish papers in the peer reviewed literature that criticise the AGW theory?

Best, Alex

Anonymous said...

As someone who has beeen called "climate skeptic" and "denier" I would like to clarify a big problem in "climate science denier-bashing".

What does the word "climate" mean and how is it used in the "climate-change"-controversy.

I am sure that everybody knows exactly what "climate change" means.

In the global warming debate "climate change" means a continious warming that is due to the climate sensitivity (warming) of GHG's (greenhouse gases).

"Climate" means the long-term evolution of weather data, like moisture, temperature etc...

The problems start when we speak about "inital value" or "boundary value" problem.
http://www.easterbrook.ca/steve/?p=1257

"For understanding climate, we no longer need to worry about the initial values, we have to worry about the boundary values. These are the conditions that constraint the climate over the long term"

Roger Pielke Senior always speaks about land use change and explains:

"The real climate system, however, is an initial value problem as the values of climate variables at any given time (in the ocean, land, continental ice and atmosphere) matter in terms of how the climate system evolves over the coming decades."

Imho the one doesn't exclude the other. There is no proof, that natural weather cycles (climate cycles) can't trigger a climate change. We would have to ask the question whether climate change can only be triggered by a change in external forcings? And I think that this question has yet to be answered.

All we can say ist that a constant rise in GHG's will warm the planet if there is no natural cooling that is stronger than this GHG-warming?

But we can't discuss about the word "climate" because it has many different meanings. If we use the word "climate" we should explain which of the definitions we use exactly. http://dictionary.reference.com/browse/climate

This reminds me of the long, stupid and pointless discussions at school about the word "conscience".

Anonymous said...

Oohps, forgot my name. It was me folks.

Yeph

Stan said...

What if we are skeptical about the basic competence of climate scientists? The evidence is strong that scientists in general, and climate scientists in particular, regularly screw up their stats. They don't replicate or even audit the work of other scientists. The rare times when work is checked, it is often wrong.

The basic priniciples of forecasting are ignored. Quality control for the databases is a disaster. The scientific method is honored mostly in the breach.

Competence is low. Hubris (arrogant pride) and logical fallacies abound. I'd likely be less skeptical, if the present ratio of competence to hubris were reversed.

Dennis Bray said...

@ Guenter Hess
On my opinion of calling people skeptics and/or deniers: To call someone a skeptic is what we are trying to sort out - what constitutes a ‘skeptic’. As I tried to demonstrate, many scientists are skeptical of some aspects of the climate change issue . To call someone a denier I guess would mean that such a person would deny the existence of climate change. As I also tried to demonstrate, this is not many people from among the sample that I use in the analysis. I agree with you that the poor distinction between ‘skeptic’ and ‘denier’ is problematic, perhaps assigning a negative connotation where none is justified.
@aber
You say ‘A definition is a (mutual) mean to know what one is talking about.’ In that sense I think ‘climate change’ is quite clear. From a simple dictionary: ‘Climate - The prevailing atmospheric phenomena and conditions of temperature, humidity, wind, etc.’ Not exactly a scientific definition but suffice here. ‘Change - becoming different.’ Hence the prevailing atmospheric phenomena and conditions of temperature, humidity, wind, etc. are becoming different - I have no problem with that. Climate is a bit like a summary of weather I think. Under what conditions would we have wind change, humidity change, temperature change ... well, perhaps climate change?
@ Alex Harvey
On Oreskes’ paper see:
Bray, Dennis‘The scientific consensus of climate change revisited’ Environmental Science & PolicyVolume 13, Issue 5, August 2010, Pages 340-350 or for a slightly different version, downloadable as a pdf filehttp://dvsun3.gkss.de/journals/2010/Bray-envscipol.pdf
I don’t know if the 65% you mention are not publishing papers. But they might not argue against anthropogenic attribution but provide comment/criticism on other aspects of the science. As for AWG theory - isn’t the theory sound? It is the projections and policy suggestions that seem to be the most contested. At least I think that is so.
@Anonymous
What does climate mean? - see above. Other than that, I am not sure how you refer to ‘skeptics’. I did not intend a debate on the meaning of ‘climate’ but on the definition of ‘climate change skeptic’ with the emphasis on skeptic.
@Stan
Who are the ‘we’? What I wrote about was skepticism AMONG climate scientists. I can’t speak for observers of the science. You might find some answers in Rob Maris’ survey on this account.

Christopher J. Burton said...

I tend to agree that it is in the realm of climate change policy that most people are skeptical. Much of the debate revolves around the efficacy of wealth transfer programs and the pureness of motive of those who advocate them.
I disagree with your use of entirely subjective terms such as healthy or un-healthy when rational or irrational would be much more accurate and testable.
The scientific method requires one to be eternally vigilant for evidence that could undermine one’s theory – this should make us all rationally skeptical. Perhaps an irrational skeptic would be someone who purports to believe in an event that can be conclusively proven wrong with consistent and repeatable empirical evidence. Following a political maxim such as the “precautionary principle” takes one out of the scientific arena and becomes a much broader value judgement.

Anonymous said...

@Dennis Bray

I just wanted to point out that the definition of the word "climate" is often used as a weapon against "skeptics":

"You don't even understand the difference between climate and weather". ;-)

But lets have a look at the reason why some have become skeptic/s ...

http://rogerpielkejr.blogspot.com/2010/10/daniel-greenberg-meets-climate.html

***Daniel Greenberg: "Roger, Re my stirring experience of jousting with Mann, Ehrlich, and Rahmstorf: What a scurrilous bunch."
- - -
"Dear Professors Mann, Ehrlich, and Rahmstorf,

Your correspondence concerning my review of Roger Pielke's book "Climate Fix" has provided me with a deeper understanding of the widespread public skepticism toward climate science. In your hands, apple pie and motherhood would come under public suspicion."***

LOL

aber said...

@ Dennis Bray: “Comment I have no problem with that. Climate is a bit like a summary of weather I think.”

I am aware that the atmospheric science is living happily without a scientifically reasonable definition of CLIMATE and WEATHER, although they use this layman expressions not only among them, but also in communication with the public and politics. Instead of ensuring minimum academic requirements, namely a clear language and definitions, it is so inviting to keep the matter discussed vague to the point of nonsense. At least it was extreme successful over the last three decades. Why caring what does it mean: “climate change scepticism”.

Hans von Storch said...

I think we have a very good definition of climate - it is the statistics of weather, and weather is the short term state of the atmosphere, ocean, hydrosphere etc. Would you agree that this is a reasonable definition, aber? I could do it a bit more formal, but that may not be necessary.

A bit of mathematics sometimes helps.

Your comment was not really helpful, if I may say so. In fact, it was just - a piece of stupid rambling.

aber said...

@ Hans von Storch: “we have a very good definition of climate - it is the statistics of weather, and weather is the short term state of the atmosphere, ocean, hydrosphere etc. Would you agree that this is a reasonable definition, aber?”

No, defiantly not! What you offer as ‘weather’ is actually a copy of the UNFCCC definition (Art.1 (3)): “….the atmosphere, hydrosphere, biosphere and geosphere and their interactions.” Even glossaries (i.a. AMS) are not offering such an empty phrase. And sorry, statistics of weather remain “statistics of weather”. Unfortunately your book with Francis Zwiers. Cambridge U press, 1999, neither provides a reasonable meaning, and which is not a mere use of a layman’s expression.

Allow me to close with a sentence I wrote almost 20 years ago : “For decades, the real question has been who is responsible for the climate. Climate should have been defined as ‘the continuation of the oceans by other means’. Thus, the 1982 (Law of the Sea) Convention could long since have been used to protect the climate. After all, it is the most powerful tool with which to force politicians and the community of states into actions.“ in: Letter to the Editor, NATURE 1992, “Climate Change”, Vol. 360, p. 292.
It was also the subject of a talk at GKSS (4th Dec. 1992), and paper (Heft 4, VdFFdGKSS-Forschungszentrum, pages 53, in English at: http://www.whatisclimate.com/
ARnd Bernaerts

aber said...

@ Hans von Storch: “we have a very good definition of climate - it is the statistics of weather, and weather is the short term state of the atmosphere, ocean, hydrosphere etc. Would you agree that this is a reasonable definition, aber?”

No, defiantly not! What you offer as ‘weather’ is actually a copy of the UNFCCC definition (Art.1 (3)): “….the atmosphere, hydrosphere, biosphere and geosphere and their interactions.” Even glossaries (i.a. AMS) are not offering such an empty phrase. And sorry, statistics of weather remain “statistics of weather”. Unfortunately your book with Francis Zwiers. Cambridge U press, 1999, neither provides a reasonable meaning, which is not a mere use of a layman’s expression.

Allow me to close with a sentence I wrote almost 20 years ago : “For decades, the real question has been who is responsible for the climate. Climate should have been defined as ‘the continuation of the oceans by other means’. Thus, the 1982 (Law of the Sea) Convention could long since have been used to protect the climate. After all, it is the most powerful tool with which to force politicians and the community of states into actions.“ in: Letter to the Editor, NATURE 1992, “Climate Change”, Vol. 360, p. 292.
It was also the subject of a talk at GKSS (4th Dec. 1992), and paper (Heft 4, VdFFdGKSS-Forschungszentrum, pages 53, in English at: http://www.whatisclimate.com/
Arnd Bernaerts

Dennis Bray said...

@ all those who seem to have trouble with the definition of climate. Isn't it a 30 year statistical mean? I really didn't think it was necessary to elaborate as it is the word 'skeptic' that was being scrutinized.

Hans von Storch said...

This term "30 year mean" is not really helpful, as it my be misunderstood as the mean value across 30 years (or an estimate thereof).

It is meant as - a statistical parameter estimated form 30 years of data (why 30 years is a nother story) - and most estimates are formed by (weighted) sums, such as variance. Obviously, variance (or standard deviation) is a climate component as well; in this catgeory are also correlations (in time, in space) - even spectra if you resort to power spectra; if you refer to maxima, percentiles, extreme values, L-moments or EOFs, CCAs etc however, this link to "(weighted) sums over 30 years of data" breaks down.

No, the "definition" "30 year statistical mean" is not reasonable. The climate is the statistics of 30 (or any other interval) years of meteorological (oceanographic etc) data, which includes co-variability across time, space and variables.

aber said...

@ Hans von Storch (November 1, 2010 10:18 PM) said... “we have a very good definition of climate - it is the statistics of weather, and weather is the short term state of the atmosphere, ocean, hydrosphere etc. Would you agree that this is a reasonable definition, aber?”

No, defiantly not! What you offer as ‘weather’ is actually a copy of the UNFCCC definition (Art.1 (3)): “….the atmosphere, hydrosphere, biosphere and geosphere and their interactions.” Even glossaries (i.a. AMS) are not offering such an empty phrase. And sorry, statistics of weather remain “statistics of weather”. Unfortunately your book with Francis Zwiers. Cambridge U press, 1999, neither provides a reasonable meaning, which is not a mere use of a layman’s expression.

Allow me to close with a sentence I wrote almost 20 years ago : “For decades, the real question has been who is responsible for the climate. Climate should have been defined as ‘the continuation of the oceans by other means’. Thus, the 1982 (Law of the Sea) Convention could long since have been used to protect the climate. After all, it is the most powerful tool with which to force politicians and the community of states into actions.“ in: Letter to the Editor, NATURE 1992, “Climate Change”, Vol. 360, p. 292.
It was also the subject of a talk at GKSS (4th Dec. 1992), and paper (Heft 4, VdFFdGKSS-Forschungszentrum, pages 53, in English at: http://www.whatisclimate.com/
Arnd Bernaerts

Rob said...

Dennis, the survey you are referencing to was held around 2008 (when I'm correct). This explains for a part the fact that only 1 total skeptic is among the respondents, while my survey shows that skepticism has increased substantially over the past two years.
And: that was a (more or less) representative survey, also limited to scientists.

Regarding some of your remarks:
- When I have used more than one definition of skeptic, that may be true, and it is probably confusing, but the other way round: also a result of present confusion, better: lack of good definition.
- "We need to make a distinction between those who work in climate science...": Is this true? For the sake of survey results analysis and scientific community yes, but skeptics are loud and influence the public opinion.
- Indeed it is simple to ask "if they are a skeptic". First, this question is not part of the survey. Second: to proclamate the survey as a survey for skeptics can be considered marketing ("hey, a survey especially for me?"). Third: a couple "luke-warmers" indeed seem to have attended the survey, hence documenting the relativity of the invitation question ("are you ..."). Fourth: the survey has a highly experimental nature.

Healty/unhealthy vs. rational/irrational (C.J. Burton): I tried to re-read parts of your posting while replacing your terms. It is not satisfying. The latter sounds better, but amplifies the distinction, which would result in a call for an intermediate term: semi-rational (which makes sense, by the way).

But let us concentrate on the skeptic issue. When anything is undertaken that has the goal of clarifying what skeptics are, be it my survey, be it the general discussion, it has the underlying goal of trying to help disarm the polarisation between the two "camps".
I think that it may be concluded that a substantial amount of skeptics are skeptic because of the attidude and work of some (or more than some) climate scientists. And: that the majority of skeptics seem to be "rational" skeptics.
To my opinion, this should be picked up by climate scientists as a motivation to improve their consciousness in the sense of being sure that all they present be strictly science, secure (as far as possible) and well-funded (or explicitly mentioning uncertaincies and what others would interprete so). At least, the rational and semi-rational skeptics should be able to coexist and hence contribute to the truly scientific discussion (without the burden of politics). Further goal: reduction of ungood feeling among the people (in the broad meaning) and politicians: who's right: (exaggerated) the alarmists or the deniers?

Finally: even when climate science would "operate" more conscious, much of what is going on in the skeptics community would continue a long time further. A german saying states: trust goes by horse, but comes back by feet.

Dennis Bray said...

@ Hans

‘The climate is the statistic of 30 (or any other interval) ...’ If the interval is not specified how is change determined? Would not the indication of change be arbitrary without specification as to change from when? For some reason I seem to remember reading once that the reference climate from which we are supposedly changing was determined by the period 1950 to 1980 - but please don’t quote me on this.

@ Rob

The survey is indeed 2008. The survey was also only limited to climate scientists. However, I do believe that so called skeptics existed in significant numbers even in 2008. They are not a new phenomenon.
Quoting my posting you say ‘”We need to make distinctions between those who work in climate science” ...: is that true?’ I would say it is true - if we are going to include the entire general population it would also have to include alarmists that ‘are loud and influenced the public’ They too are skeptical of ‘under estimates. here the distinction might be made between ‘skeptics’ and so-called ‘deniers’.
I don’t believe I said the survey simply asked if they are skeptic. But I do believe the survey was directed at self proclaimed skeptics, in which case the question is implicit - but I might be wrong. However, I don’t think I made any strong criticisms against your survey.
Healthy/Unhealthy vs. Rational/Irrational: A simple question - Isn’t it possible to have irrational claims from the alarmist group; that perhaps irrational would point to any extreme position? What I was trying to address was skepticism that is found in healthy science as compared to skepticism founded in other than a scientific perspective. Unhealthy/healthy might not have been the best use of terms but I think they conveyed the meaning.

Philip said...

Dennis: "After all, outside of our area of expertise we are limited to expressing opinion [...] The question is: ‘How skeptical must I be before I am given the label of skeptic?’"

Climate science encompasses a lot of different specialities and most researchers I understand claim expertise only in a subset. Presumably a climate scientist is entitled to be a scientific skeptic (that is, to doubt the consensus) only in her areas of expertise. But to my mind, the problem with this is that it is too narrow - a 'skeptical climate scientist' is usually taken to be skeptical of a broader position.

A scientifically trained outsider looking critically at climate science is likely to see a core of very sure basic physics surrounded by a wide range of opinion on how that sure physics will play out in the real world. At one end of this range he could find experts talking about effects that are barely measurable, whilst at the other end experts concluding that climate system collapse is likely to occur. Since I think this is the pertinent issue, a more useful definition of 'skeptical climate scientist' might simply be one who doubts that climate system collapse will occur.

Werner Krauss said...

@Hans #11

Hans, I am skeptical when reading your definition. Maybe one should be more precise: "The climate of (mathematical) climate science is the statistics of weather".

I am a skeptic because I am not sure if mathematical climate really covers all of the phenomenon. Instead, it think it covers the mathematical climate only.

Concerning the 30 years: Strauss / Orlove have a nice time scale for differentiating weather / seasons / climate:
Weather is a daily event; seasons are, well, seasonal, and climate is generational. (in: Weather, Climate, Culture).

Alex Harvey said...

Dennis #6,

Perhaps my reasoning was not valid, because if 65% of scientists were doing research aimed at disproving/falsifying anthropogenic attribution and they were all failing, then indeed that would be consistent with Oreskes 2004 and your own findings.

That said, I think if 65% of scientists were doing research aimed at disproving/falsifying anthropogenic attribution, I would bet the level of certainty for anthropogenic attribution would be much higher than it actually is.

(It is a shame there is no baseline in these studies. For instance, I would like to know how certain these scientists are about less controversial things, e.g. the correctness of the equations of radiative transfer. Without questions like this, it is difficult to interpret the results.)

Let me change my question.

The only scientists I am aware of who are actually trying to 'break' the models used to establish anthropogenic attribution are Lindzen & Spencer.

Is it just that I am unaware of other scientists who are also trying to falsify the hypothesis of anthropogenic attribution, i.e. trying to show that models are broken?

All the research I hear about seems to be aimed at showing instead that the models are pretty good, e.g. Andy Dessler's work, which seems to be aimed at showing that models can reproduce the water vapour effect.

Best, Alex

Marco said...

Alex,

The null hypothesis that the models are right or the null hypothesis that the models are wrong are equally valid starting points to test that null hypothesis. Even *if* Andrew Dessler starts out with the null hypothesis that the models can reproduce water vapour effects, it is ultimately the data that decides whether the null hypothesis is accepted or rejected. That Dessler finds 'his' null hypothesis to be accepted may be inconvenient for you, but it is scientifically and morally an equally valid starting point as the other null hypothesis (which Dessler would reject, since the models DO describe water vapour effects quite well).

Alex Harvey said...

Marco,

Is that actually right?

I read Kuhn's 'The Copernican Revolution' (awhile ago) and was impressed that using ancient astronomical data one could set out with the null hypothesis of Tycho Brahe's geoheliocentric cosmology and quite honestly fit the data to this hypothesis.

Surely, it is necessary for scientists to be actually try to contradict their theories in order for our knowledge to be refined?

What I'm not sure about is how many scientists are actually trying to do that. Maybe Dessler is? I recall, on the recent survey posted here, scientists had a mean confidence of 3.62 on a scale of 1 to 7 on their confidence in models' ability to simulate the water vapour effect. That would suggest that Dessler is one of the most confident of scientists on this issue.

Best, Alex

Dennis Bray said...

@Alex

Perhaps I can offer some insights here. Again, reference is to the survey conducted in 2008. Climate scientists were asked:
Concerning what science is in general, what would you say is its main activity?
23.98% answered ‘to falsify existing hypothesis’
27.25% answered:: ‘to verify existing conditions’
48.77% answered ‘other’
a second question read
Concerning science in general, the role of science tends towards:
12.64% answered ‘deligitimization of existing ‘facts’’
37.08% answered ‘legitimization of existing ‘facts’’
50.28% answered ‘other’

Marco said...

Alex, Tycho Brahe's model was quite good at modeling the position of the planets as a function of time. Thus, even though his model was wrong on other accounts, it was very useful for this particular element. If your research focuses on the position of the planets, this is the only important parameter.

The same applies to the climate models: they are apparently quite good at modeling water vapour. Even if all other things are wrong, this element is apparently right. How would Dessler have to challenge the climate models if they do something properly?

It remains that the entry point is the same: you have a model that makes predictions, you test those predictions. They are either right or wrong (Let's for the sake of the argument forget there's a grey area in-between). There is thus no difference in the null hypothesis being "the models are right" or "the models are wrong". You can repeat the experiments when you have more and/or more accurate information (as was done with Brahe's model), which may actually change the outcome. THAT's the challenge science can put out for its models.

Marco said...

Alex, sorry for posting twice, but I think the survey issue requires a separate note:
Surveys are tricky things, I'm sure Dennis will agree, where you get an expert opinion that does not necessarily agree with a layman's opinion. As scientists we usually want more and more accurate data. But that does depend on the area one is interested in. When I work on the international economy, I probably won't care too much about local details. If, however, my area of interest is how small-scale farming (e.g.) affects the regional economy, I'd need much more detailed information. In situation 1 I'd likely claim the information is good enough (5-6), while in situation 2 I'd likely call the data insufficient (2-3). To compare to the climate arena: the models are apparently pretty good in getting an average idea of rainfall (more or less), but are much less accurate in their regional descriptions. Which makes the climate scientist unhappy with the model, but is then easily overinterpreted by the layman that the climate scientist is also uncertain about the global average.

Günter Heß said...

@Marco

But then as an analogy the scientist can explain the decline and not hide the decline

Marco said...

Günther: not if that explanation requires several pages that do not change the larger story, and when that story is only allowed to be very few pages. Note that the accompanying article for the WMO report does point to the divergence problem.

Case-in-point: anti-vaxxers used the NON-left-censored autism data to claim autism was caused by thimerosal. Scientists had to use several scientific terms to explain why this was a false assertion (short version, autism cannot be diagnosed conclusively in young children without several years of observation): the average person in the public did not understand a darn thing those scientists said. End of story: obfuscators won.

Günter Heß said...

Marco,
I used it as an analogy and I guess you understood me well enough.
I can follow your logic, but unfortunately your line of reasoning is according to my opinion very often abused as a lame excuse for obfuscating science in a messy political discussion.
Therefore, I think the only avenue for science is to take the risk of being misunderstood and stay with scientific rigor.
Best regards
Guenter