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Comments 33901 to 33950:

33901. Tom Curtis at 07:58 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R is now running the misinterpretation of the classifications scam vs Cook et al 2013 (ie, claiming that the criteria for endorsement in Cook et al is only that some warming since 1950 be anthropogenic).  I say it is a (rhetorical) scam because it was not the first or intuitive response of AGW "skeptics" to that paper.  The first response was that authored by Poptech, in which Nicolas Scaffeta wrote:

       "Cook et al. (2013) is based on a strawman argument because it does not correctly define the IPCC AGW theory, which is NOT that human emissions have contributed 50%+ of the global warming since 1900 but that almost 90-100% of the observed global warming was induced by human emission."

       You will notice that correctly identifies the Cook et al criteria for endorsement, ie, that it indicates that 50% plus of recent warming was anthropogenic, and tries to call it a strawman because it does not match his blatant misrepresentation of the IPCC position.

       Indeed, if a paper that endorses only that some recent warming is anthropogenic belongs to the Cook et al 97%, then both Sceffeta's and Shaviv's papers (discussed by Poptech) should have been classified as endorsing the consensus.  Likewise, if a paper that endorses only that some recent warming is anthropogenic belongs to the Cook et al 97%, then all four of Richard Tol's papers which he claims to not have endorsed the consensus, should have been classified as endorsing the concensus.

       A number of major AGW "skeptics" and Richard Tol have endorsed these claims of misclassification, including Watts (who reposted the claims), Tol who reposts it and a number who have commented either at WUWT or on Tol's tweet without demuring that Shaviv's description of the Cook et al classification was wrong.  In fact, I have been unable to find one objection to Scaffeta's claims, or the claims that these papers were misrated based on the supposed fact that the Cook et al 97% endorsed only some anthropogenic warming rather than 50% +.  

       That, of course, merely demonstrates that the AGW "skeptics" are inconsistent in their criticism of Cook et al.  It does not demonstrate that Scaffeta (and Tol's) 50%+ interpretation is correct.  So, let us examine the possibility that "level of endorsement of AGW" in Cook et al means just endorsement of the claim that at least some of recent warming has been anthropogenic (ie, that anthropogenic factors have not had either no effect, or tended to cool recent temperatures).

       So, consider the classification scheme used in Cook et al:

       "Table 2. Definitions of each level of endorsement of AGW.

       Level of endorsement Description Example
       (1) Explicit endorsement with quantification Explicitly states that humans are the primary cause of recent global warming 'The global warming during the 20th century is caused mainly by increasing greenhouse gas concentration especially since the late 1980s'
       (2) Explicit endorsement without quantification Explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a known fact 'Emissions of a broad range of greenhouse gases of varying lifetimes contribute to global climate change'
       (3) Implicit endorsement Implies humans are causing global warming. E.g., research assumes greenhouse gas emissions cause warming without explicitly stating humans are the cause '...carbon sequestration in soil is important for mitigating global climate change'
       (4a) No position Does not address or mention the cause of global warming
       (4b) Uncertain Expresses position that human's role on recent global warming is uncertain/undefined 'While the extent of human-induced global warming is inconclusive...'
       (5) Implicit rejection Implies humans have had a minimal impact on global warming without saying so explicitly E.g., proposing a natural mechanism is the main cause of global warming '...anywhere from a major portion to all of the warming of the 20th century could plausibly result from natural causes according to these results'
       (6) Explicit rejection without quantification Explicitly minimizes or rejects that humans are causing global warming '...the global temperature record provides little support for the catastrophic view of the greenhouse effect'
       (7) Explicit rejection with quantification Explicitly states that humans are causing less than half of global warming 'The human contribution to the CO2 content in the atmosphere and the increase in temperature is negligible in comparison with other sources of carbon dioxide emission'"

       For this categorization to be consistent it must satisfy two criteria:

       1)  No paper must fall under more than one classification;

       and

       2)  If different levels of concensus represent different minimum percentages of anthropogenic contribution, they must change monotonically with classification level.

       Now clearly if "endorse AGW" means "endorse that "at least some of recent warming has been anthropogenic", then the categorization fails criteria (1).  That is because any paper endorsing >0% but <50% anthropogenic warming must be categorized either 2 or 3, but also 7.  Further, it also fails condition (2) for category 1 clearly applies only to papers which endorse 50% or more anthropogenic contribution to recent warming, while category 7 applies only to papers that endorse less than 50% anthropogenic contribution.  The only monotonic ordering of endorsement levels possible, therefore, is on in which for all categories endorsement of AGW means endorsing 50% or more of recent warming as anthropogenic, and disendorsing means endorsing less than 50%.

       If there are two ways to interpret a paper, one of which is consistent, and one of which is inconsistent, then clearly we must give preference to the consistent interpretation.  Doing otherwise merely raises a strawman.  Therefore, there is no rational way to interpret endorsement in Cook et al as anything other than "endorsement that 50% or more of recent warming was anthropogenic".

       Ironically, despite this several AGW "skeptics" have criticized Cook et al both for using a definition of endorsement that allowed even hardcore deniers to belong to the 97% and also for being inconsistent.  They prove thereby that there intent is only to criticize, not to actually rationally critique the paper.

33902. Russ R. at 07:31 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       KR:

       "You reference several blog posts by J. Duarte - who seems to feel that the Cook et al authors were dishonest idiots (the paper passed peer review of methods and results by reviewers the editors respected for domain knowledge), that the raters were blinded by ideological bias (totally ignoring the author ratings giving confirming identical results), complaining about raters discussing criteria (when it's essential for everyone to agree on the same critera, clarifying ambiguities - and that radom presentation prevented collusion on any particular item), and in general making truly absurd and unsupported accusations."

       
       Let's look at some of his claims then, shall we?

       First:  "The Cook et al. (2013) 97% paper included a bunch of psychology studies, marketing papers, and surveys of the general public as scientific endorsement of anthropogenic climate change."  

       Cook and Nucitelli claim their team reviewed "over 12,000 peer-reviewed climate science papers" and that papers which were "not climate-related" were excluded from the analysis.

       Yet "in ten minutes with their database" Duarte found 19 papers that were included as endorsing the consensus, which were clearly not "climate science" papers.

       His list begins in the fourth paragraph here.   

       The first two examples:

       Chowdhury, M. S. H., Koike, M., Akther, S., & Miah, D. (2011). Biomass fuel use, burning technique and reasons for the denial of improved cooking stoves by Forest User Groups of Rema-Kalenga Wildlife Sanctuary, Bangladesh. International Journal of Sustainable Development & World Ecology, 18(1), 88–97.

       or

       Boykoff, M. T. (2008). Lost in translation? United States television news coverage of anthropogenic climate change, 1995–2004. Climatic Change, 86(1-2), 1–11.

        

       Would you argue that any of these should be considered "climate science" papers?

        (snip)

       Moderator Response:

       [RH] You're going to have to find a way to do this without Duarte as his entire premise violates SkS policy:

       • No accusations of deception.  Any accusations of deception, fraud, dishonesty or corruption will be deleted. This applies to both sides. You may critique a person's methods but not their motives.

       It's been suggested many times over that Duarte, if he feels the results of Cook et al are not correct, he should endeavor to produce his own research into the issue.

33903. Russ R. at 06:59 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Sorry, was trying to respond to the moderators comments @312, but for some reason my last comment was repeated.  
       
       I'll try again... shorter this time:

       "Please note that the OP is written by John Cook and Dana Nuccitelli. Cook is the lead author of Quantifying the consensus on anthropogenic global warming in the scientific literature, Cook et al, 2013, Environmental Research Letters. Nuccitelli is a co-author of the ERL paper. Are you stating that Cook and Nuccitelli deliberately misrepresented the findings of the ERL paper in the OP?"

       No, I'm not refering to the OP (i.e. "Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature" Posted on 16 May 2013 by dana1981, John Cook).

       I'm specifically refering to another post (and subsequent comments), The 97% v the 3% – just how much global warming are humans causing? Posted on 15 September 2014 by dana1981.  

       Dana writes:

       "96–97% of climate experts in arguing that humans have been the dominant cause of global warming since 1950"

       and 

       "96–97% of climate science experts and peer-reviewed research agree that humans are the main cause of global warming."

       These claims are not supported by Cook et al (2013), since only 1.6% of the reviewed papers stated "that humans are causing most of global warming".

       Whether the overstatement is deliberate or not, I don't care to speculate. But it is a misrepresentation regardless.

33904. KR at 06:43 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R. - Once again, you are ignoring details such as Category 4, "a natural mechanism is the main cause of global warming" - excluding humans as a minor cause from 1, 2, and 3

       Not to mention the instructions for applying categories:

       The second drop down indicates the level of endorsement for the proposition that human activity (i.e., anthropogenic greenhouse gases) is causing global warming (e.g., the increase in temperature). 

       Not "a cause", but "causing", as in the main actor. Instead, you play rhetorical games, reject common English usage, and ignore the context within which the categories were defined. 

       You reference several blog posts by J. Duarte - who seems to feel that the Cook et al authors were dishonest idiots (the paper passed peer review of methods and results by reviewers the editors respected for domain knowledge), that the raters were blinded by ideological bias (totally ignoring the author ratings giving confirming identical results), complaining about raters discussing criteria (when it's essential for everyone to agree on the same critera, clarifying ambiguities - and that radom presentation prevented collusion on any particular item), and in general making truly absurd and unsupported accusations. 

       Your uncritical presentation of his blog rants as support is, IMO, the clearest evidence that you are far more interested in attacking conclusions that ideologically offend you, than actually concerned about the methods that highlight those conclusions - playing the man and not the ball, a type of ad hominem fallacy. 

33905. Russ R. at 06:38 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Don't worry KR, the paper's methods do more than enough to discredit it, but that's a different matter, which I can get into later.  (Or you can read for yourself here, here, and here.)

       (snip)

       Assuming for the moment that the methodology was valid, I'm only objecting to a misrepresentation of its findings, specifically the word "most" in "humans caused most of the warming."  (I have absolutely no objection to the claim that "97% of papers stated (implicitly or explicitly) that humans are causing warming")

       The word "most" can only apply to Level 1 endorsement that actually contain some measure of attribution.  It does not appear in Level 2 or 3 endorsement.  To claim that these abstracts support a consensus of "most warming being caused by humans" is outright false.  They say no such thing:

       1 Explicit Endorsement with Quantification: paper explicitly states that humans are causing most of global warming.
       2 Explicit Endorsement without Quantification: paper explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a given fact.
       3 Implicit Endorsement: paper implies humans are causing global warming. E.g., research assumes greenhouse gases cause warming without explicitly stating humans are the cause.

       For the record, if asked, I'd self-rate my own personal opinion as Level 2 "endorsement without quantification".  So, this isn't part of a denier agenda. 

       (snip)

       I just expect this website to accurately report the paper's actual findings... not make up whatever suits your cause.

       But do what you like... it's your credibility that you're risking.

       Moderator Response:

       [RH] You'll have to conduct this discussion without the aid of linking to outside sources accusing fraud.

33906. John Hartz at 06:16 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R: Please note that the SkS Comments Policy includes the following prohibition:

       No accusations of deception. Any accusations of deception, fraud, dishonesty or corruption will be deleted. This applies to both sides. You may critique a person's methods but not their motives.

33907. Russ R. at 06:08 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Don't worry KR, the paper's methods do more than enough to discredit it, but that's a different matter, which I can get into later.  (Or you can read for yourself here, here, and here.)

       Assuming for the moment that the methodology was valid, I'm only objecting to a misrepresentation of its findings, specifically the word "most" in "humans caused most of the warming."  (I have absolutely no objection to the claim that "97% of papers stated (implicitly or explicitly) that humans are causing warming")

       The word "most" can only apply to Level 1 endorsement that actually contain some measure of attribution.  It does not appear in Level 2 or 3 endorsement.  To claim that these abstracts support a consensus of "most warming being caused by humans" is outright false.  They say no such thing:

       1 Explicit Endorsement with Quantification: paper explicitly states that humans are causing most of global warming.
       2 Explicit Endorsement without Quantification: paper explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a given fact.
       3 Implicit Endorsement: paper implies humans are causing global warming. E.g., research assumes greenhouse gases cause warming without explicitly stating humans are the cause.

       For the record, if asked, I'd self-rate my own personal opinion as Level 2 "endorsement without quantification".  So, this isn't part of a denier agenda. 

       I just expect this website to accurately report the paper's actual findings... not make up whatever suits your cause.

       But do what you like... it's your credibility that you're risking.

       Moderator Response:

       [JH] Please note that the OP is written by John Cook and Dana Nuccitelli. Cook is the lead author of Quantifying the consensus on anthropogenic global warming in the scientific literature, Cook et al, 2013, Environmental Research Letters. Nuccitelli is a co-author of the ERL paper. Are you stating that Cook and Nuccitelli deliberately misrepresented the findings of the ERL paper in the OP?

33908. KR at 05:14 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R. - Then perhaps you should actually read the Cook et al paper, paying some attention to the exclusive (i.e., pick only one) and ordered endorsement categories in that methodology. Categories applied to how AGW was referenced, how the literature (and authors) regard AGW, not just to what are explicitly attribution studies. 

       If your abstract/paper implied, expressed, or explicitly stated that people have minimal impact on climate change, i.e. "a natural mechanism is the main cause of global warming", your abstract/paper would be rated as 5, 6, or 7 respectively. 

       If your abstract/paper implied, expressed, or explicitly stated that "humans are causing global warming" - note, not "contributing" but "causing", i.e. the primary or dominant cause as per any reasonable use of English, the abstract/paper would be rated as 3, 2, or 1 respectively. 

       From the methodology, the instructions to the authors for self-ratings: "Note: we are not asking about your personal opinion but whether each specific paper endorses or rejects (whether explicitly or implicitly) that humans cause global warming":

       The claim that only category 1 ratings count is utter nonsense, raised only by ignoring the categories as a whole, taking the AGW endorsement ratings out of context from the AGW rejection categories. And by what I consider deliberate misreading of "are causing" as the semantically distinct "are a cause". 

       I will note that this issue has been discussed at some length - I suggest you read through some of this thread. As per the categories which describe whether an abstract/paper endorses/rejects AGW, 3896 endorsed and only 78 rejected it. 

       ---

       What I find most fascinating is that the rated abstracts are made readily available - it would be almost trivial to define your own categorization criteria, as specific as you want, and review a hundred or so abstracts in an afternoon to see if those criteria gave different results. Nobody criticizing Cook et al has stepped up to this. 

       I suspect (personal opinion) that's because everyone realizes that the only way to get a significantly different percentage from rating the literature is to do it wrong, with patently absurd criteria. And that barring any support for 'skeptic' positions from the data, the only avenue they have left is to nitpick, misinterpret, and distort in an attempt to discredit (not disprove) the conclusions. 

33909. Composer99 at 05:08 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R:

       I would say you're playing at rhetorical silly buggers, and your attempt to limit the response space to your carefully-worded set is insultingly obvious.

       Basically, your line of reasoning only makes sense if you ignore studies of paleo- and historical (read: Holocene) climate and simultaneously ignore the physics of greenhouse gases.

       Consider how Cook et al defines category 3 (implicit endorsement):

       Implies humans are causing global warming. E.g., research assumes greenhouse gas emissions cause warming without explicitly stating humans are the cause

       Given historical climate and physics, the only way that implicit endorsement means "implicitly endors[ing] that humans are a cause of warming" where "a" is something less than primary (that is, over half) is if there is some as-yet undiscovered sink absorbing human CO₂ emissions and, simultaneously, an as-yet undiscovered source of CO₂ that is releasing it into the atmosphere - and moreover, the CO₂ from this mysterious source just happens to possess a carbon isotope signature that matches fossil fuel CO₂ as a total coincidence.

       I'm pretty sure we're getting into extraordinary claims requiring extraordinary evidence territory here, so I think you need to pony up some research hinting at these as-yet undiscovered sources and sinks if you wish to persist with this line of argument.

33910. Dikran Marsupial at 04:53 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       RussR, I think you are missing an important point about academic publishing in general and climatology in particular.  Journal papers tend not to make specific claims in the abstract of a paper unless the contents of the paper specifically addresses that particular question.  However, quite often the abstract will indirectly refer to some piece of commonly accepted knowledge in providing background or motivation for the question actually addressed in the paper.

       In climatology, there is a type of paper known as an "attribution study" which seek to discover what factors explain climate in some region or period of time.  It is only in these papers where you should expect the abstract to contain an explicit statement on the cause of the warming.  However, most climate papers are not attribution studies, and discuss some other aspect of climate change.  For instance I contributed to a paper on statistical downscaling (which relates large scale atmospheric circulation to small scale local climate).  The methods for this are the same whether the climage change is anthropogenic or natural or a bit of both, so there is no good reason for it to have anything more than implicit acceptance (in explaining the reasons why downscaling is likely to be a useful thing to do).

       The measure used by TCP is perfectly reasonable, if you understand the nature of scientific publication, and are aware that attribution studies are only a small fraction of the papers publiched on climate change.

33911. Russ R. at 04:28 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       KR,

       happy to discuss in the appropriate thread... reposting what I wrote before:

       Only 64 out of 11,944 abstracts reviewed by Cook et al (2013) were rated as "Explicit endorsement with quantification", stating that "humans are the primary cause of global warming".

       That amounts to a "0.5% Consensus" (64/11,944).

       Excluding the 7,930 abstracts which were viewed to take no position, the ratio (64/4,014) rises to a "1.6% Consensus".

       The reported "97.1% Consensus" excludes those abstracts which took no position, but includes 2,910 abstracts that do not explicitly state that humans are a cause of warming, and 922 that explicitly identify humans as a cause of warming, but not quantify the amount or state that humans as the primary cause.

       Does anyone dispute the above?

       According to the data, only 1.6% of abstracts said that "humans are the primary cause of recent global warming".

       Consensus at the 97% level did not include quantification, so it's factually misleading to say that the 97% position is that humans caused "most" of the warming.

       Citing this paper you can say that:

       • 97% of papers implicitly endorse that humans are a cause of warming, or that
       • 24.6% of papers explicitly endorse that humans are a cause of warming, or that
       • 1.6% of papers explicitly endorse that humans are the primary cause of warming.

       Which will it be?

33912. Firgoose at 03:59 AM on 18 September 2014
       2014 SkS Weekly News Roundup #38A
       

       @Ashton: According to the site where the report can be obtained, FS-UNEP Global Trends in Renewable Energy Investment 2014 ...

       "the investment drop of $US35.1 billion was partly due to the falling cost of solar photovoltaic systems. The other main cause was policy uncertainty in many countries, an issue that also depressed investment in fossil fuel generation in 2013"

33913. gws at 01:15 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       @jwalsh and TomC, your discussion is interesting, but is it goal oriented?

       I think the more interesting observation comes from a link that was only in the Guardian version, in which Dan Kahan muses about what makes people like Curry tick. His analysis and the comments, some of which could easily act as an unsolicited sample of people like Curry, point to a fascinating pschycological phenomenon, the fact that you can "know" but still deny. The derogative term sometimes used for that is the "smart idiot effect".

       I have little doubt that the "3%" and their followers have the capacity to understand the science. Most are very smart people and have/had distinguished careers. We scientists have a hard time comprehending why they deny (or partially deny) the obvious. The evidence is clearly not in their favor and their arguments are weak at best. Yet their existence, publicity, and popularity with the pervading neo-liberal politics of the times spells doom for everybody. Is it any wonder we dislike or despise them?

       So, as good scientists, we try to analyze them. Kahan and others are contributing most to that. I think his analysis is useful at worst, and right-on at best. While Curry most likely suffers from "dualism" (see above link), the followers, may also include the other three categories Kahan lists. "Dualism" seems a more common pathology to me than expected. I think if any of us are self-critically examining ourselves, we may find some form of "dualism" we hold, where the evidence is crystal clear to us, but we still deny all or parts of it (like Curry) for unrelated reasons (knowing that, or finding it after reflection of yourself means you converted from "dualism" to "partitioning"). Religion (e.g. the "muslim doctor" story in Kahan's blog) is a prime example. For the 3%, it is somewhat obvious that a neo-liberal ideology is the reason for their "dualism". They are not that shy about that at all (Curry: "I am independent, with libertarian leanings."), and they do not understand that their positions show clear contradictions, i.e. they are unaware of their "dualism", considering it the normal position others should hold as well.

       We already know that arguments from evidence are very unlikely to convince somebody in denial. And while normally ignoring or minimizing the person suffering from the dualism pathology is a way to deal with the issue (since the person's pathology is not neccesarily harmful to her/himself or society), it is not in the case of global warming, because 1. the person's societal influence is out-proportional relative to the occurrence of the pathology, and 2. the consequences for society are therefore potentially disastrous.

       While calling out Curry and others on their "dualism" may not be nice, it may be a start to find a way out. Her logic has already been called flawed, but, like the "muslim doctor", we cannot expect her to realize that. Alas, we should read up on "dualism" in the pschycology literature to see if there is a way to address and ameliorate the pathology, and, like in the case of the broader issue of "denialism", begin developing a communication strategy.

       For the by-standers, it will remain important to highlight the contradictions in the "dualist's" mind, since this is the only way to highlight why is makes little sense to follow these people if you want to prevent or address the consequences of warming.

33914. Rob Honeycutt at 01:15 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Stranger @48...  I have asked the exact same question innumerable times on various forums over the past year or so. It doesn't even take funding to replicate, it just requires some dedication of time.

       It really doesn't even require that much time. Cook et al was really overkill in terms of the number of papers. You could easily get a robust statitistical sampling with much smaller numbers, something like Oreskes did. 

       What I also know (and I think "skeptics" also know), is they'll end up with the exact same result. I read a large number of the abstracts for Cook et al and I can say, with no hesitation, the number of papers that reject AGW are vanishingly small. 

       This ends up being exactly like the hockey stick in that, those attacking the paper are merely trying to find reasons to reject the conclusions rather than actually test the results. They aren't looking for the truth, they're looking to bury the truth.

33915. Stranger8170 at 00:54 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       I don't know if anybody asked jwalsh why the skeptics don't do their own survey and present it for peer review? It seems like the Koch brothers or some other benefactor could come up with a little chump change to find out. They helped fund Richard Muller’s historical temperature reconstructions. Of course it didn't pan out for the skeptics since Mueller found out the Hockey Stick was the real McCoy. I wonder if that’s the reason they haven't made an attempt to shoot down Cook et el by doing their own research? Obfuscation may be the only arrow left in their quiver.

33916. KR at 00:16 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R. - This thread is on the particular discussion of attribution, based on the discussion between Schmidt and Curry (who clearly misinterprets the IPCC report on this matter).

       Misinterpretations (such as yours) of Cook et al methodology should be discussed on an appropriate thread, and I have replied there. 

33917. KR at 00:14 AM on 18 September 2014
       Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
       

       Russ R. - Given that the question asked by Cook et al was really "what percentage of the literature agrees with the consensus", and that implicitly (Cat. 3) or explicitly (Cat. 2) were using the consensus position as a background fact of the abstracts and papers, your post is utter nonsense.

33918. DSL at 00:08 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Good grief, Russ: not THAT again.  How many studies quantified attribution?  

33919. Russ R. at 00:05 AM on 18 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Only 64 out of 11,944 abstracts reviewed by Cook et al (2013) were rated as "Explicit endorsement with quantification", stating that "humans are the primary cause of global warming".  

       That amounts to a "0.5% Consensus" (64/11,944).

       Excluding the 7,930 abstracts which were viewed to take no position, the ratio (64/4,014) rises to a "1.6% Consensus".

       The reported "97.1% Consensus" excludes those abstracts which took no position, but includes 2,910 abstracts that do not explicitly state that humans are a cause of warming, and 922 that explicitly identify humans as a cause of warming, but not quantify the amount or state that humans as the primary cause.

       Does anyone dispute the above?

       Moderator Response:

       [JH] When you pivot to a totally different topic, please find the appropriate OP and post your comments there. Pleae follow KR's recommendation. 

33920. Ashton at 20:13 PM on 17 September 2014
       2014 SkS Weekly News Roundup #38A
       

       In view of the predictions (generally dire)  about climate change/global warming I wonder why new investment in clean energy is declining in many countries (http://tinyurl.com/qxvdvg5).  I was most surprised that new investment in clean energy by Germany in 2013 was 40% below that in 2012.  Is this because Germany has now decided that clean energy is now less desirable/necessary than previously thought? Are the falls of 33% in France and 73% in Italy also due to the belief by those governments that investment in clean energy can now be scaled back?  In view of the hatred of the Abbott government in Australia by the Greens and their supporters, it is a surprise to see that the 4% fall in Australia's investment in clean energy is, with China, the lowest decline in the nine countries showing a decline.  On that, of the 12 countries listed that only three  had  invested more  in clean energy  in 2013 than in 2012.  Why are so many countries apparently not heeding the advice of the IPCC and climate scientists?

33921. jwalsh at 17:28 PM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Tom Curtis @42

       The title of the article is, "The 97% v the 3% – just how much global warming are humans causing?". Leaving out 62% of the title, with no indication that you have done so represents misquotation, and in this case, out of context quotation to boot. Both are forms of dishonesty, and in academic situations are regarded as a type of academic fraud.

       Tom, I seem to have touched a nerve, but there was a method to my madness.  And yes, I take more care in an academic context compared to a comment on a blog.  However, I might truncate a title when discussing an actual academic paper within the confines of comments attached to that exact paper, assuming that if someone got that far, I'd think they would have read the title already.  And I don't think I'd be accused of "fraud".  Sloppy? Subjective. "Concise" would be my preference.  I could have just as easily left any portion of the title out (or all of it), and I think people would have got the gist. Haha.

       Tom Curtis @42

       More importantly, the 97% and the 3% are mentioned in the title and paper, but not discussed.

       I disagree. The author defined 3% of climate experts as believing a sub 50% anthropogenic attribution in the first paragraph of the article and referenced (at least on the newspaper page) Cook 2014 as the source of that figure.  If it were unimportant....

       So, who cares? Why am I picking nits?  I believe the IPCC consensus view and I believe strongly that we really need to be doing something about it.  But care needs to be excercised in communicating about it. Why? Because there's a strong danger similar to the "crying wolf" parable. Over-stating a case, and exaggerating the degree of consensus is potentially damaging in the effort to convince those who don't believe that CO2 is causing warming.  I think we need to be prepared for things like the "pause" continuing beyond this year. What if it winds up being 28 years? Or 40 years?  I personally think that's unlikely.  But it's going to be a tough sell made a lot harder by over-stating a case and then back-pedaling. Extreme caution needs to be exercised in delineating what is known and what is still in the theoretical realm.  But that's just my opinion.

       Tom Curtis @42

       If you wish to interpret the article as "The IPCC position vs a fringe consensus position" with the understanding that the arguments of those who don't make that fringe position are even worse than the poor arguments by Curry, I doubt Dana (or anybody else at SkS) will care. It is a non-issue.

       What I wish is pretty irrelevant, but if I were to be pinned down to characterize the Schmidt/Curry debate over attribution, I would say that Schmidt's position is Schmidt's position and Curry's is Curry's.  I don't think Gavin Schmidt would consider himself as speaking for the IPCC any more than Curry would think she is speaking for a larger fringe group.

33922. Tom Curtis at 15:05 PM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       jwalsh @38:

       "As good as the outputs of the CMIP5 series of models are in providing much of the data for the AR5 graph in question, nobody considers them completely definitive. If that were the case, the over-prediction of temperature wouldn't be a current issue for the modelers. And it is."

       I do not think anybody is claiming the models are "definitive".  That is why the estimates have error margins.  Leaving aside the fact that the models are not the only basis of the attribution, the fact that error margins were shown, and then expanded to allow for uncertainties in the method shows that you are arguing against a strawman.  Further, you are arguing inconsistently in that you assume any increased uncertainty must reduce the percentage of the anthropogenic contribution, whereas it is equally likely to increase it.

33923. Tom Curtis at 15:00 PM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       jwalsh @41:

       "But I'll try and stay on topic. The Topic of the article was "The 97% v. the 3%"."

       The title of the article is, "The 97% v the 3% – just how much global warming are humans causing?".  Leaving out 62% of the title, with no indication that you have done so represents misquotation, and in this case, out of context quotation to boot.  Both are forms of dishonesty, and in academic situations are regarded as a type of academic fraud.  I presume in your case they represent sloppy practise, however sloppy practise that gives an appearance of greater strength to your argument than actually exists.

       More importantly, the 97% and the 3% are mentioned in the title and paper, but not discussed.  Specifically, there is no discussion of what specifically divides the two groups, nor of how we know it, or even of the significance of the division.  Rather the terms "97%" and "3%" are merely used as labels, with the discussion in the article (and hence the topic of the article) restricted to the IPCC's attribution statements with particular regard to Fig 10.5.  The article could have easilly used labels such as "accepters" and "challengers" of the IPCC consensus, and it would have made no difference to the substance of (and hence the topic of) the article.

       As labels they are not ideal in this case, in that Curry does (barely) accept that 50% of recent warming has been anthropogenic with a very large error margin.  As such, she nominally falls inside the consensus position as categorized by Cook et al (and more directly relevant, Doran et al, 2009).  She is, however, clearly a challenger of the IPCC consensus position.  If you wish to interpret the article as "The IPCC position vs a fringe consensus position" with the understanding that the arguments of those who don't make that fringe position are even worse than the poor arguments by Curry, I doubt Dana (or anybody else at SkS) will care.  It is a non-issue.

       (I don't think that would be an accurate presentation, in that I don't think Curry's arguments and overall position are consistent with a genuine 50/50 position.  But whether it is accurate or not, it is irrelevant to the substance of the article.)

33924. scaddenp at 14:33 PM on 17 September 2014
       Antarctica is gaining ice
       

       Oh, a final thought - sea ice and albedo is rather different between arctic and antarctica. Running the numbers can done and see here for one example.

33925. jwalsh at 13:55 PM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       " Your distortions of Cook et al sugest that is not too unkind an assessment."

       I wish you'd pointed out how I distorted it (email me?). But I'll try and stay on topic.  The Topic of the article was "The 97% v. the 3%".

       But to avoid any distortions on my part. From the Cook paper. "Among abstracts that expressed a position on AGW, 97.1% endorsed the scientific consensus."  and "Among self-rated papers not expressing a position on AGW in the abstract, 53.8% were self-rated as endorsing the consensus."

       Category 2 of Explicit Endorsement in the Cook paper was defined as "Explicitly states humans are causing global warming or refers to anthropogenic global warming/climate change as a known fact"

       Curry is at least Category 2 by believing the anthropogenic component is roughly 50%. In fact, I'm uncertain what percent would qualify, but 50 should knock it out of the park! Heh.

       So, if Schmidt and Curry debate, it's really between two people within the 97%. If you want to hear from the 3% (and I am uncertain why you would, as defined), someone else needs to step up.  However, realistically Schmidt speaks for himself, and Curry speaks for herself.

33926. scaddenp at 13:11 PM on 17 September 2014
       Antarctica is gaining ice
       

       And here are figures showing increasing temperature of the circum-antarctic ocean and its decreasing salinity.

       

       Source:

       Interesting paper, co-authored by Judith Curry, also noting the increasing sea temperatures here.

33927. Tom Curtis at 12:30 PM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       jwalsh @39, the list of Bart Verheggen's articles is here, as found from the "Author's Posts" page.  The top two relate to Verheggen et al.  I note that there is every reason, when you are attempting to quantify the opinions of people in a certain group (scientists who have published in the peer reviewed literature on climate science) to not include an extraneious group who have not published in the peer reviewed literature on climate science solely because they hold a particular opinion on the topic.  Beyond that, your statistical manipulations bring to mind the saying about lies, damned lies and statistics ....  Your distortions of Cook et al sugest that is not too unkind an assessment.  Not to put to fine a point on it, the claim that the Cook et al categories measured "that at least part of the warming was man-made" is a lie; and one concocted after the initial reaction to the paper showed the "skeptics" to have interpreted the paper correctly, ie, a test of endorsement of the claim that 50% plus of recent warming was anthropogenic.  (I make no claim as to whether or not you are deliberately decieving, or merely hoodwinked.)

       I repeat, if you want to discuss the paper in detail, dicuss it where it is on topic.

33928. jwalsh at 10:38 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       [quote]Verheggen et al increased their sample by including a group of AGW "skeptics" who would not otherwise have met the criteria. Further, many of the scientists surveyed are not expert in attribution, whether expertise is determined by relative number of papers, or by field of study. Therefore simplistic interpretations such as yours are not warranted. I am not going to go into it here, however, where it is off topic. If you want to discuss it in detail, there are several blog posts on this site in which Verheggen discusses the paper. They are most conveniently found by using the "author's posts" page under the "about" menu. [/quote]

       I am new to the site, and didn't see Verheggen as the author in the drop-down.

       I have read both Cook 2014 and Verheggen 2014 in entirety.

       And yes, Verheggen's paper included what was said to be 5% of respondents culled from those taking a contrary position. Which frankly concerned me when I read it. Applying multiple pre-selection criteria is another sort of potential bias.  And why wouldn't you include a spectrum of beliefs if you were trying to quantify that spectrum? Hmmm.... However, using back of napkin math, removing 5% of those thinking it's unknown or less than 50% brings it to roughly 70/30.  Still a far cry from 2-4%.  I noticed that the Cook 2014 study was the reference for 2-4%.  Under that study, the 97% figure was for those papers that were subjectively deemed to hold a position that at least part of the warming was man-made. And under that definition Curry is very much NOT a part of the "2-4%".  The majority of papers were deemed to not take a position in the abstract. Which leads one to speculate that the authors possibly did have an opinion, but you just couldn't tell from the abstract. Reading the full paper might be instructive in that case, or you could just ask them. Isn't that what Verheggen did?

33929. scaddenp at 10:01 AM on 17 September 2014
       Antarctica is gaining ice
       

       Geothermal heat and ocean heat are both things that are measured. I pointed you to papers on both here and here. You seem to be simply ignoring measurements in those comments and going argument from Personal Incredulity and rhetoric ("Madagascar's beaches").

       "The overall combined total of southern and northern sea ice, is very high this year and last year, and therefore ice/water solar reflectivity is "on average, near it's recorded peak". Can you cite your reference for this please? Albedo change is related to summer ice extent so I am having some difficulty with this claim.

33930. jwalsh at 09:18 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       As good as the outputs of the CMIP5 series of models are in providing much of the data for the AR5 graph in question, nobody considers them completely definitive. If that were the case, the over-prediction of temperature wouldn't be a current issue for the modelers. And it is.

        

       There will of course, be a CMIP6 series. In fact one of the stated goals of the CMIP6 project is " What are the origins and consequences of systematic model biases?"

       CMIP6 outputs will no doubt be part of AR6.  It will be interesting to see the differences.  But whether they are much improved will require additional decades of data to see.

33931. Ken in Oz at 09:09 AM on 17 September 2014
       2014 SkS Weekly Digest #37
       

       I've noticed that Tamino's Open Mind blog is inactive, with comments stopped. Anyone know if this is temporary or permanent, as Tamino has been a superior source of insights and information.

33932. Tom Curtis at 09:08 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       jwalsh @16, before proceeding, I would like to introduce Fig 10.6, which shows estimates of the contributions of various factors on a purely empirical basis:

       

       Based of that chart, and using Folland (2013) as showing the lowest Anthro contribution, you can derive the following attribution estimates:

       Volcanoes 0.00%
       Solar -6.31%
       ENSO 10.81%
       AMO 0.00%
       Anthro 95.50%
       Nat -6.31%
       Int Var 10.81%

       I think those estimates overestimate the ENSO contribution by not using the SOI index, but that is neither here nor there.  The important thing here is that the estimates shown are well within the 1 sigma range for table 10.5.  Now, if you prefer to use a 95.5% anthro contribution rather than a 107.7%, that's fine by me.  But there is no justification for claiming that the IPCC estimates are solely model based, nor that rellying on emperical estimates will result in low estimates of the Anthro contribution.

       Turning now to your points:

       "But I fundamentally stand by my orginal assessment. The 10.5 graph was primarily derivative of a very small group of papers discussing model outputs."

       You can stand by it all you like, but the further reading of the IPCC report clearly shows that additional factors went into determining the Anthro contribution, and especially the Internal Variability contribution.  (Your claim is true in the restricted case of Greenhouse and OA).

       "My take was that the 10.5 graph was never intended to display the full picture of attribution, or theories behind it. And the considerable text in the section supports that view, rather than disproves it."

       Nobody is claiming that Fig 10.5 was intended to display the full picture.  It was, however, intended to display the simplest graphic summary of the IPCC findings, as is shown by the repeated citations of it in the Executive Summary.  Further, the Executive Summary states:

       "It is extremely likely that human activities caused more than half of the observed increase in GMST from 1951 to 2010. This assessment is supported by robust evidence from multiple studies using different methods. Observational uncertainty has been explored much more thoroughly than previously and the assessment now considers observations from the first decade of the 21st century and simulations from a new generation of climate models whose ability to simulate historical climate has improved in many respects relative to the previous generation of models considered in AR4. Uncertainties in forcings and in climate models’ temperature responses to individual forcings and difficulty in distinguishing the patterns of temperature response due to GHGs and other anthropogenic forcings prevent a more precise quantification of the temperature changes attributable to GHGs. {9.4.1, 9.5.3, 10.3.1, Figure 10.5, Table 10.1}"

       (Original emphasis.)

       Note that quoteing the less emphatic findings on greenhouse gas contribution is misleading because there is a higher uncertainty about the greenhouse gas contributions than about the total anthropogenic contributions as shown in Fig 10.5 and discussed extensively above.

       For what it is worth, based on Fig 10.5, the there is 90% confidence that greenhouse gases caused 54% or above warming, and 95% confidence that it caused 31% or above.  Clearly the statement you quote as proving a lack of reliance on Fig 10.5 shows no such thing.  There is more basis on the the section I quoted, with Fig 10.5 showing the 95% confidence ("extremely likely") at 79%, and 99% confidence ("virtually certain") at 67% contribution.  That, however, can be attributed to the IPCC's well known caution.

       Regardless, even the IPCC's "extremely unlikely" finding, together with both empirical and model based methods showing near 100% mean attribution shows that conclusions finding near 50% attribution are simply unwarranted.  They are the result of bias, not analysis (and very plainly so in the case of Curry).

       "Verheggen et al. 2014 asked a number of climate scientists to provide a figure for attribution ..."

       Verheggen et al increased their sample by including a group of AGW "skeptics" who would not otherwise have met the criteria.  Further, many of the scientists surveyed are not expert in attribution, whether expertise is determined by relative number of papers, or by field of study.  Therefore simplistic interpretations such as yours are not warranted.  I am not going to go into it here, however, where it is off topic.  If you want to discuss it in detail, there are several blog posts on this site in which Verheggen discusses the paper.  They are most conveniently found by using the "author's posts" page under the "about" menu.  

33933. sidd at 08:31 AM on 17 September 2014
       Thousands of ‘Nameless Short-Lived Lakes’
       result of calculation in last sentence of my last post will be in mm and mm/yr
33934. sidd at 08:26 AM on 17 September 2014
       Thousands of ‘Nameless Short-Lived Lakes’
       Mr sauerj: see fig 8 in Hansen(2012) "Paleoclimate ..." linked to by Mr. M. A. Rodger at 1:50 AM 14 sep 2014. Then divide y axis by 360.
33935. Tom Curtis at 08:08 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Rob Honeycutt @25, certainty about the strength of radiative forcing does not translate directly into certainty about the relative temperature response, both because of uncertainty about climate sensitivity and uncertainty about relative effectiveness of different radiative forcings.  Further, Russ R's point is about the relative uncertainty of Anthro, Greenhouse and OA as shown on fig 10.5.  His point is invalid, but I have to agree with him that the figure you show is irrelevant to the discussion.

       Further, if it were relevant it would support his case as the uncertainty of all anthropogenic forcings is significantly larger than the uncertainty of any individual element, and likely larger (and at least comparable in size to) the uncertainty of Greenhouse radiative forcing or OA radiative forcing.

33936. Tom Curtis at 08:00 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R @various:

       1)  The formula  combining uncertainties on addition is:

       σ_A²=σ_x²+σ_y²+2*ρ*σx*σy,

       where σ_A is the uncertainty of the combined term, while σ_x and σ_y are the uncertainties of of the two terms summed to derive the combined term.  In this particular case, that means we can treat σ_A as the uncertainty of Anthro, and σ_x and σ_y as the uncertainties of Greenhouse and OA respectively.  This had already been explained to you in words by Bob Loblaw (@9 and 10), and the base formula from which (together with definitions) the above can be derived had been given to you by Kevin C (@19).  It should be noted that the formula can be used for any level of uncertainty, not just one standard deviation (1 sigma), provided the same level of uncertainty is used for each term.  It should also be noted that the formula assumes the distribution of uncertainty is normal (I believe).)

       2)  It has already been noted in discussion above by J Walsh (@13) that the relative uncertainties for Greenhouse and OA are derived from the model ensemble, scaled to the observed warming (as noted by me @15); and the graph representing the relevant values presented by me (also @15).  From this, simple visual inspection will show the clear anticorrelation of Greenhouse and OA.  Further, simple visual inspection of column C will show the very low variance of Anthro.  What is more, the logical reason for this relationship has been mentioned to you several times by different respondents, including by me in my second pont @2.  As I predicted @7, your entire discussion since has simply been a process of ignoring the information already presented you in the second comment on this thread. 

       3) Anthro is not only constrained by the relationship Anthro = Greenhouse + OA, but also by the relationship Anthro = Obs - (Nat + Internal Variability).  Therefore its uncertainty is more tightly constrained than the constraints of just Greenhouse and OA.  That allows its uncertainty to be tighter than it would be if calculated from just those two.  It also allows other information in addition to scaled relative contributions in the model ensemble to enter determining the values of Anthro, as discussed above @15.

       4)  For the sake of argument, if we allow the (known to be false) assumption that the uncertainty of Anthro was constrained by Greenhouse and OA alone, we can then calculate a derived uncertainty using the relationships between Greenhouse and OA shown on Figure 10.4.  They in fact show a correlation of -0.92.  Consequently, the "very likely" uncertainty range for Anthro would be 0.16 C.  However, the IPCC then relaxed that estimated uncertainty from a "very likely" to a "likely" range.  Therefore the strict and pedestrian calculation on the basis that you suggest would have resulted in a tighter "likely" range than is shown in Fig 10.5, not a broader range, and indeed would have required a "likely" range less than +/-0.08 C.

       5)  Even if we allow the (known to be false) assumption that the uncertainty of Anthro was constrained by Greenhouse and OA alone, and still follow the IPCC in dropping "very likely" to "likely" ranges, that would still only result in an "likely" range of +/- 0.16 C, and a less than 1% chance of the Anthro contribution being less than 50%.

       Your horse is dead, and already flogged into a bloody ruin.  Will you cease floging it.

33937. Rob Honeycutt at 07:37 AM on 17 September 2014
       Antarctica is gaining ice
       

       jetfuel...  Can you please provide sources for these?

33938. jetfuel at 07:31 AM on 17 September 2014
       Antarctica is gaining ice
       

       Two arguments support growth of Antarctic sea ice which hit 19.7M sq km Sept 14th. One is the loss of Arctic ice has exposed the ocean surface there to release more heat than previously. When it was covered with ice, it's ability to give off heat was less. The second argument is that the increased ice covered area at the southern polar region is reflecting more of the sun's energy than ever before. These same two arguments can be used in reverse: The Antarctic ice area is covering more sea water than ever and allowing it to retain it's heat, and at the Arctic, the less than average amount of sea ice is reducing reflectivity of the sun's energy. The overall combined total of southern and northern sea ice, is very high this year and last year, and therefore ice/water solar reflectivity is on average, near it's recorded peak. With the Arctic sea ice looking like it will not dip below 5M sq km this summer, there will be an increase again in multiyear ice there.

       The recent articles I've read downplaying this record Antarctic sea ice are using what happened in 2012 as the overriding factor. Right now, the sea ice ring around Antarctica is now an average of 750 miles in width, and is actually widest and most massive at the Ross Ice Shelf. The Ross Ice Shelf is noted in 2012 as being in danger of dissipating to unleash the West Antarctic Ice Sheet into the Ross Sea. For warm water today to flow under nearly 1000 miles of sea ice, then enter the Ross Sea, and then traverse through a thin water layer area the size of Texas, under a km thick of ice, then still be warm enough to melt the underside of a 2000 foot thick glacier's edge? I would be more inclined to believe the heat source is the Earth's core, not warm ocean water from Madagascar's beaches that has made that arduous journey described above.

33939. Rob Honeycutt at 07:06 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ... Responding to your comments on what we know and don't know that we don't know (or whatever):

       That is the whole point to constraining uncertainties. There is always some possibility that there is something out there on the fringes that's having an unknown influence, but given the large amount that is known on a wide range of factors, what's left that could have a significant influence becomes highly improbable.

33940. KR at 06:39 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R. - Actually, what you are saying, what you are claiming, is that the IPCC stated uncertainties for natural forcings, for internal variation, and/or for observations are wrong. 

       I await your references refuting the IPCC AR5 summaries on these matters. In the meantime, well, you are just arguing by assertion. IMO such arguments do not stand in the face of the evidence. 

33941. Rob Honeycutt at 06:31 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ... I'm not questioning your figure of ±0.4°C (which is why I didn't quote it), I'm challenging your interpretation of it. Again, the IPCC clearly states that GHG forcing has a high and very high level of certainty on these.

33942. Russ R. at 06:10 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Rob,

       You can keep arguing, or you can admit that I quantified (correctly) the amount of uncertainty as ±0.4°C.  

       You chose to omit that detail in your attempt to argue against me.

       Was I wrong or not?

       Awaiting your apology.

       Moderator Response:

       [JH] Please keep it civil.

33943. Russ R. at 06:08 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       No KR,

       I'm saying we know what we know, and that we don't know how much we don't know.

       But we don't know all there is to know.  And only by presuming that we know all there is to know can we claim that the uncertainty of the remainder is low.

33944. KR at 05:49 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R. - You did, I assume, also note the uncertainties on natural forcings and on internal climate variability? Which are each +/- 0.1°C? And the uncertainties on observations, +/- 0.05°C?

       Again, the total forcing is well known, so are the natural and internal variation forcings - meaning that the higher uncertainties in GHGs and other anthropogenic forcings are indeed negatively correlated.

       1+1+G+A=4, G+A=2. It's really that simple. As Rob points out, you appear to be invoking little green men - claiming that we must not know what we know. 

33945. Rob Honeycutt at 05:45 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ...  You state "We only know GHG to a low level of certainty" [my emphasis] and the far left column of the radiative forcing chart clearly states that we have a "H" (high) or "VH" (very high) level of certainty for well mixed greenhouse gases, which clearly make up the dominant forcing.

33946. Russ R. at 05:37 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Rob Honeycutt @ 26:

       You misquoted me by leaving out the quantity.  

       ""But what we actually do know about ANT directly is far more uncertain. We only know GHG to a low level of certainty..."

       Hm. Actually, I believe that is wrong...

       What I actually wrote:

       "We only know GHG to a low level of certainty (±0.4°C),"

       Which is exactly the value in the IPCC's chart above, and is a low level of certainty relative to the ±0.2°C claimed for total ANT.

       Still believe I'm wrong?

33947. dhf at 05:27 AM on 17 September 2014
       97 hours of consensus: caricatures and quotes from 97 scientists
       

       @ Tom Curtis at 10:58 AM on 16 September, 2014

       It is not my claim that calibrations can be performed by laymen. One point I tried to make was that properly presented test result can be easy to comprehend even if the model is complex and that properly presented data are strong arguments.

33948. Rob Honeycutt at 04:43 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R...  What I'd suggest here is that, in order to work, the argument you're putting forth here would require a yet unknown mechanism that un-explains the high level of certainty that we have about greenhouse gases, and adds a yet-so-far completely unknown forcing to take its place.

33949. Rob Honeycutt at 04:16 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       Russ R. said @24... "But what we actually do know about ANT directly is far more uncertain. We only know GHG to a low level of certainty..."

       Hm. Actually, I believe that is wrong. We have a high to very high level of scientific understand about the radiative forcing of anthropogenic greenhouse gases:

       

33950. Russ R. at 03:37 AM on 17 September 2014
       The 97% v the 3% – just how much global warming are humans causing?
       

       KR,

       Your comment relates to the concept that OBS - (NAT + INT) = ANT.  (In other words, anything we can't explain must be anthropogenic.)

       Yes, observed warming has very little uncertainty, and the warming ascribed to NAT and INT is claimed to be quite certain (±0.1°C), but is unfortunately limited to the extent of our knowledge of those processes (which is turning out to be more uncertain than previously thought).  It's necessarily a case where we simply don't know how much we don't know.

       But what we actually do know about ANT directly is far more uncertain.  We only know GHG to a low level of certainty (±0.4°C), and know virtually nothing about OA except to say that it is equal to ANT - GHG.

       But to say that we know ANT to a high level of certainty (±0.2ºC) is only possible if we assume that we know everything about NAT and INT with high certainty.  Which is the same as assuming a high level of certainty of ANT.

       And we can't simply assume that the uncertainty of the components (GHG & OA) is negatively correlated because the uncertainty of ANT is assumed to be low.

       Circular reasoning works because circular work.

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