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Comments 45401 to 45450:
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Riduna at 09:43 AM on 20 May 20132013 SkS Weekly Digest #20
JH - How eminently sensible - and that cartoon, surely one of the best published by SkS!
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KR at 07:44 AM on 20 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
I find discussions like this delightful - although I find myself wanting to wave my arms as I talk, scribbling back and forth on a white-board.
I invariably learn from them, even in the (all too common, sadly) case of finding I was completely mistaken. :)
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CBDunkerson at 07:30 AM on 20 May 20132013 SkS Weekly Digest #20
On the, "If you know of any media coverage which is not listed on the page, please let us know in the comments and we'll add it."... were you looking to include hatchet jobs or not? I note that Watts, Bishop Hill, Tucson Citizen, and other denier outlets that miscast the survey aren't listed... but Science 2.0's article insinuating that it was a non peer-reviewed vanity paper is included.
Moderator Response:[JH] Dana writes the text for the SkS in the News sectuion of each Weekly Digest. That is where the sentence you quote comes from. It is therefore appropriate for him to respond to your question.
As the creator of the Weekly News Roundup and the News Bulletin, I studiously avoid including articles from denier outlets such as the ones you have listed.
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scaddenp at 07:22 AM on 20 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
This has been a very interesting discussion and I would be very disappointed if an aggressive tone led to a premature conclusion. I would really encourage the participants to keep discussing the science. It's rare to see such debate online.
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Jim Eager at 06:01 AM on 20 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Herrhund, first, GCR induced cloud nucleation climate forcing is very far from being an established theory supported by the full body of evidence. But more important, as DSL pointed out, any GCR effect, regardless of sign or magnitude, would in no way negate the radiative physics of CO2 and other greenhouse gases, nor negate the observed fact that burning fossil carbon has increased atmospheric CO2 by ~42%, thereby forcing Earth's energy budget out of balance. Any GCR effect would be entirely separate and in addition to the known anthropogenic enhanced greenhouse forcing, and not in any way be an alternative hypothesis. In short, it would neither endorse nor refute the AGW hypothesis.
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Dikran Marsupial at 03:02 AM on 20 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
I'm sorry Dr Tung, I explained why it is important to look at the spread of the model runs as that is the way in which the models characterise internal variability. You agree with me on this point, as you wrote "I agree with everything you said except the last paragraph", yet you then follow this by "discussing model-observation systematic discrepanices", without reference to the spread of the model runs and concentrating solely on the ensemble mean.
Of course the model ensemble means don't exactly match the observations, but this is not evidence of a systematic discrepancy, it is evidence of a stochastic/chaotic discrepancy, which the spread of the models clearly tells us we should expect to see.
I will now bow out of the discussion. I have explained why I feel your comment was unfair, and explained the two reasons for this, and asked you "Do you disagree with either of these statements? If so, please can you explain why.". I am perfectly willing to change my mind if I am wrong, but if polite questions are asked that are designed to address a misunderstanding, and those questions are ignored, the chance of a productive discussion are rather slim. Note I did not mean to imply that your comments were deliberately unfair.
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KK Tung at 02:07 AM on 20 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to post 54 by Dikran Marsupial: I agree with everything you said except the last paragraph, where you still accuse me of being unfair to modelers. I am one of them and I had no intention of doing so.
What is nice about this way of communication is that what we said are all recorded. You can go back to reread what I said and see if I was being unfair. My statements were about what we could learn from the models, in particular about model-observation systematic discrepancies. We have looked at both CMIP 3 and CMIP5 model result archives, at individual model's ensemble means where it is available. What it reveals to me is a tendency for the model ensemble means to under predict the observed warming in the early half of the 20th century. I wanted to learn from this model result, while you thought I was a unfairly attacking the hard working modelers. I suggested that the discrepancy was possibly due to the absence of internal variability in the ensemble mean. The ensemble means were not supposed to contain much internal variability. We both agree with that.
The intermodel spread is an entirely different matter.
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From Peru at 01:54 AM on 20 May 20132013 SkS Weekly News Roundup #20B
What happened with my HTML hyperlinks?
Moderator Response:[DB] Manually writing the html results in what you initially saw. The new commenting features incude a WYSIWYG interface. You can highlight your selected text and then click the Insert/Edit Link button to establish a hyperlink to your selected text. I fixed your html in your previous comment.
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From Peru at 01:51 AM on 20 May 20132013 SkS Weekly News Roundup #20B
I am confused by this paper in Nature:
Long-term warming restructures Arctic tundra without changing net soil carbon storage
That shows that at a site where for 20 years there was simulated greenhouse warming, "there was no net change in total soil carbon ( P=0.5) or nitrogen stocks" and "After 14 years of warming, greenhouse plant carbon stocks had increased by 50%"
I am not surprised from the increase in plant (vegetation) carbon, that was already found in other studies, but the "no change in total soil carbon" seems at odds with a lot of papers that studied this problem before.
Any idea of what is going on?
Note on "other papers": I was thinking in papers like this:
The effect of permafrost thaw on old carbon release and net carbon exchange from tundra
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CBDunkerson at 22:45 PM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
Joshuas193: You can find answers to all of those questions on this site. The list of common issues on the left and the search panel should both help.
1: China is the largest emitter in total and the US the largest emitter per person. However, that isn't the right question. This isn't a problem caused by one, or two, or a dozen countries. Rather, there are only a handful of countries which are not a significant part of the problem. See this link for info.
2: The only currently viable solution is to switch to power sources which do not emit carbon dioxide. Various geo-engineering schemes have been proposed, but none seem likely to work. Many countries have begun clean power programs, but thus far they have mostly just slowed emissions growth. The US is one of only a few countries which has actually been able to decrease emissions... by converting large amounts of power generation from coal to natural gas, but that can only go so far.
3: The tech exists and should actually cost much less than fossil fuels... except that fossil fuels receive massive direct and indirect subsidies which have kept them in use. Unsubsidized solar PV power is now falling below even the heavily subsidized cost of fossil fuels in sunny parts of the world. See renewable power and fossil fuel subsidies.
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MA Rodger at 22:28 PM on 19 May 20132013 SkS Weekly News Roundup #20B
chriskoz @3
The paper by Chen et al is on-line here.
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Tom Curtis at 22:26 PM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Longhornmaniac8 @134, I believe you've got the idea, but you have your figures wrong. When normalizing the original abstract ratings to allow for detected bias, I get the following for all papers rated:
Total: 11944 (100%)
Affirm: 7349 (61.53%)
Neutral: 4334 (36.29%)
Unsure: 22 (0.18%)
Reject: 239 (2.0%)Ignoring neutral papers, that gives us:
Total: 7610 (100%)
Affirm: 7349 (96.57%)
Unsure: 22 (0.29%)
Reject: 239 (3.14%)So, even adjusting for bias as best we are able with publicly accessible figure, the 97% concensus figure looks very solid, although it is possible that the original abstract rating understated rejections (1.2 vs 3.1%). We should not make the mistake of thinking that normalized figures are superior to the original abstract ratings. They no doubt contain their own biases, and some dubious projections. The figure for "unsure" papers is based on projections from just 5 out of a 1000 papers.
The normalized figures do not supplant the original figures, therefore, but help flesh out how robust those figures are. Various critics of this paper have pointed out a number of possible causes of error (many of which are imaginary). They have not, however, tended to flesh out the criticisms with numerical values. When you do, as you can see, the original figures continue to look very good.
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chriskoz at 20:39 PM on 19 May 20132013 SkS Weekly News Roundup #20B
An interesting article on the shifting poles due to the Greanland melt. Obviously they have the data from GRACE and the data should confirm the SLR contribution by icesheets.
But an interesting aspect is, as Jianli Chen, the lead author says, they have some polar shift data going back 100y. With that data, they can estimate the Greenland melt, hopefully quite precisely for those 100y, well before GRACE. It will an interesting development.
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Dikran Marsupial at 20:14 PM on 19 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Dr Tung, electronic forms of communication have a tendency to be percieved (on both sides) as being more aggressive than is intended. None of what I have written is intended as an attack on you, but is intended to understand your statements and to discuss and correct errors where they appear. That is the way science should work. I find the best way to go about this is to ask direct questions and give direct answers; however when they are not answered this inevitably leads to misunderstandings.
The ensemble mean is the models estimate of the forced response, I think we can agree on that.
Now I would say that the spread of the ensmeble (at least for a particular model) characterises the plausible effects of the unforced response (i.e. natural variability) and the observations can only be expected to lie within the spread of the models runs and no closer. Do you agree with that?
Now you have said that the spread of the models is wide, and I have agreed that it is. However, what I want to know is whether you think there is good reason to expect the spread of the models to be any smaller than it is. This question is intended to help me understand why you appear to think that the models under-predict the warming. As far as I can see it doesn't, the warming lies within the stated uncertainty of the hindcast.
Essentially when comparing observations with models you need to look at BOTH the ensemble mean AND the spread of the ensemble as they are both integral parts of the projection/hindcast. If you only look at the ensemble mean and igniore the spread, you are ignoring the information about internal variability that the model provides.
I'm sorry, but in my view you are being unfair in suggesting the modellers use the ensemble mean because they can't predict chaotic phenomenon, firstly becuase the forced component is the answer to the question posed by the politicians and secondly because they don't ignore internal variability, the spread of their model ensemble is a characterisation of internal variability. If the modellers only used the ensemble mean the comment would be fair, but they don't. Do you disagree with either of these statements? If so, please can you explain why.
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noelfuller at 18:32 PM on 19 May 20132013 SkS Weekly News Roundup #20B
There is some good comment with links on the report on sealevel rise projections just published here:http://www.carbonbrief.org/blog/2013/05/scientists-warn-of-up-to-70-cm-of-sea-level-rise-by-2100,-but-is-this-better-or-worse-than-we-thought -
noelfuller at 18:26 PM on 19 May 20132013 SkS Weekly News Roundup #20B
With respect to the Telegraph story on Fiji villagers moving uphill and others doing the same there is reference made to a new study on sea level rise by 2100 (but no link) where the maximum sea level rise is misquoted as 27cm. In fact the study claimed 27 inches or 69 cm. -
BillEverett at 17:18 PM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
Joshuas193@11, you can find answers to some of your questions via WBGU-World_in_Transition.doc.
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dhm60 at 16:59 PM on 19 May 2013Trillions of Dollars are Pumped into our Fossil Fuel Addiction Every Year
An intresting piece on one of the denier groups (Intitute for Energy Research) can be found here: www.instituteforenergyresearch.org/2013/04/03/the-imfs-outlandish-claims-about-energy-subsidies/
Standard approach - question the science (Big Oil pay way too much tax) while denigrating the work (outlandish?). I guess the IMF are now part of the great big global AGW conspiracy now. :o That's the IMF - part of the Washington Consensus!
btw: The IMF did a good paper on petroleum subsidies in 2010 entitked "Petroleum Product Subsidies: Costly, Inequitable, and Rising". Worth reading. http://www.imf.org/external/pubs/ft/spn/2010/spn1005.pdf
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KK Tung at 16:42 PM on 19 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to post 51 by Dikran Marsupial:You have taken my statements on model-observation discrepancy out of context. We all seem to agree that ensemble mean model results reveal the forced response. And we all agree that this one realization that is our observed climate in principle contains internal variability as well as forced response. If model ensemble mean systematically under predicts the observed warming, as happens in the first half of the 20th century, it is legitimate for a scientist to ask whether the difference could be caused by the presence of internal variability in the real climate. To me the discrepancy is revealing and is what we should be learning from models. This is not a criticism of the models. You first claimed that the difference was insignificant because the internal variability is unpredictable by models and quoted AR4 to support your view. Then when I replied that your position was essentially asking us to ignore internal variability you accused me of being deeply unfair and uncharitable to the community of hard working scientists. I am sorry that our scientific discourse has taken this sad turn.
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Bert from Eltham at 16:38 PM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
There is 100% consensus from the denialist camp on the validity of consensus in scientific matters of peer reviewed papers especially with this peer reviewed paper. Does their opinionated only consensus even negate their own premise? It is a perfect example of circular thinking. Sad. Bert
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scaddenp at 16:00 PM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Herrhund. There was an interesting review of the CLOUD results at RealClimate which gives some indication of why the research is interesting and worth doing. However, it also outlines succinctly the steps required for the results to even relevant to the question of global climate change. Do you believe new results from CERN are going to advance any of these steps further?
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Joshuas193 at 15:31 PM on 19 May 2013Antarctica is gaining ice
Ok, so I am a noob here. but if I am reading this right there is increased loss of Land Ice in Antarctica and this fresh water freezes easier causing the sea ice to be greater? And even with the rise in temperature it is too small to cause the sea ice to melt. Is this basically the short version of the article?
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jyyh at 15:04 PM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
please also delete my response to the fretsliders second post, he admitted getting a good response that I didn't see before posting that and delete also this one...
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Longhornmaniac8 at 14:48 PM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Tom Curtis @ 131,
Thanks for the reply. I see what you're doing there, used it as inspiration to come up with the following values:
Assuming (as you mentioned) there was a false positive on 169 of the abstracts, this means that 622 (791-169) of the papers were listed as endorsing the consensus in both the abstract and self reviews.
This provides us with 1342, the total number of self-reviews endorsing the consensus (622+[.538*1339]).
Using the same assumptions you made, 27 of the papers identified as neutral in the abstracts were self-identified as rejecting the consensus (although this assumes as well that there were no abstracts identified as rejecting the consensus that were self-identified as no position). 27/1339=2.02%.
This leaves us with the remainder of 592, which were identified as netural in both the abstracts and self-reviews. 592/1339=44.2%.
So:
53.8% of No Position abstracts self-review as endorsing the consensus;
44.2% of No Position abstracts self-review as No Position;
2.02% of No Position abstracts self-review as rejecting the consensus.We can use these numbers to slightly adjust the abstract totals to provide a more comprehensive analysis.
37.2% (4447 [3896+720-169 we know were misidentified in the abstract]) were identified as endorsing the consensus in either the abstract review or self-review.
61.6% (7352 [7930-747+169]) were identified as No Position in either the abstract review or the self-review.
1.2% (145 [78+40+27]) were identified as either rejecting the consensus or uncertain in either the abstract review or self-review.Of those papers having a position, 96.8% were identified by either the abstract review or self-review as endorsing the consensus, roughly the same as the numbers used by the authors, but a fun side track nonetheless!
Cheers!
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Joshuas193 at 14:47 PM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
hi everyone. I'm new here. I have some questions.
Since it appears that pretty much everyone agrees about AGW. We need to start working on some solutions.
1. What/who are the largest contributors of greenhouse gasses? I think i saw that China now puts out nearly twice what the US does.
2 What can be done to lessen or stop this. Are any of the major polluters doing anything to stop ?
3 Are there current technologies that can be implemented now to reduce the greenhouse gas levels. Is it a funding issue or is the tech not there yet?
Anything you can answer/or links you can provide would be appreciated.
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Tom Curtis at 11:27 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Over at Lucia's Blackboard there is a largely irrational discussion of the paper, but Lucia raises one interesting point. Many of the papers implicitly accepting that >50% of late twentieth century warming is due to anthropogenic causes are papers looking at the consequences of that warming. Contrary to Lucia's assumption, most (65.45%) such papers ended up being classified as neutral, but never-the-less her idea of first classifying papers by the IPCC Working Group to which they belonged, and only classifying WG1 papers by level of support for the concensus. In her opinion, only WG1 papers are relevant to the issue.
Fortunately, the searchable database subclassifies papers as Impacts (equivalent to WG2), Mitigation (equivalent to WG3), and Methods and Paleoclimate (equivalent to WG1). Using that feature it is simple to determine that 92.94% of "WG1" papers that state a position affirm that anthropogenic forcings are responsible for >50% of recent warming; while only 7.06% deny it. So, even using Lucia's classification it is clear a consensus exists.
The problem is, I believe Lucia's classification to biased. She motivates it by talking about acceptance of AGW by biologists, and asking just how relevant that is to assessing the consensus. She ignores the fact that many "impacts" and "mitigation" papers look at the effects of global warming on the hydrological cycle, or frequency of storm events, etc. Assessing these issues requires a large overlap of skills with those required to assess the direct effect of CO2 on temperature (and are often done by the same people). Lucia's classification merely excludes a large number of papers that are relevant, and in a maner which biases the result.
Even biological impact papers are arguably relevant to the concensus, in that the biologists must at least make themselves familiar with the detailed predictions to write such papers. However, even accepting Lucia's point on this detailed classification, she has not shown that excluding them will have a significant impact on the survey results.
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Roger D at 11:00 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
It seems in some opinion pieces that deny the consensus (and at the same time propose that consensus in science is not important) there is a curious inability to understand the basis of the 97%. For example in: http://tucsoncitizen.com/wryheat/2013/05/18/cooking-consensus-on-climate-change/
In which the author writes:
"The actual findings of the survey, in Cook’s own words: “We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming.” So how do you get a 97% consensus out of that?"
Somehow, even though the opinion piece itself expicitly includes the qualifying statement that the 97% figure is for papers addressing the cause of global warming (i.e. 33.6% of all papers surveyed), these "skeptics" are still confused. Hard to believe that something so basic can stump them.
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Tom Curtis at 09:50 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Longhornmaniac8 @129, relevant information is in Table 5. Assuming that no paper rated as endorsing AGW based on the abstract was rated by its authors as rejecting AGW (and vice versa), from that table it can be seen that, of papers rated as having no position, or being undecided on AGW and which were self rated, 551 (41.25) where rated as self rated as affirming AGW, 761 (56.8%) were self rated as neutral or having no position, and 27 (2%) were self rated as rejecting AGW.
The discrepancy is no doubt because some papers rated from the abstract as affirming AGW were self rated as neutral. In fact, approximately 169 (21.4% of affirmation rated papers) must have been rated as affirming AGW by the SkS team, but self rated as neutral. Even though the survey generated some false positives, the ratio of false positives to false negatives is 0.4, indicating a strong conservative bias in the rating method.
Looking at a total comparison of abstract rated to all self rated papers, it is evident that the SkS rating team showed two distinct biases (in aggregate). There was a very strong bias towards rating papers as neutral which applied across the board. There was a weaker bias to rate rejection papers as neutral shown by the larger self rated/abstract rated rejection papers (3.25) than for affirmation papers (1.7).
The former is discussed in the paper, and is largely attributed to the reduced information in the paper, but I am inclined to think is in significant part due to too conservative a methodology. The later is not discussed. Some residual personal bias cannot be entirely excluded, but it is more likely (IMO) to be due to a tendency among rejection papers to hide that rejection deep in the paper in a few lines that are not, in fact supported by the rest of the analysis (as for example, in McLean et al, 2009).
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Alexandre at 09:19 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
My German is not as good as it used to be, but this link herrhund posted looks a lot like statements from a Brazilian 'skeptic' meteorologist (Luiz Carlos Molion): vague claims, supported by vague inductive reasoning. In the German case, some visual correlation between sun spot activity and temperature (not always global). In the Brazilian case, visual correlation between PDO phases and global temps. No quantification of effects, no error bars, no statistical analyses.
To those who want desperately to find some article with graphs and figures saying they are right, that's enough. If you don't have science, an article like that is as good as it gets...
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John Hartz at 08:07 AM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
miffedmax:
No surprise there given how Deniersville is merely an echo-cahmber, full of sound and fury, and signifying virtually nothing.
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Longhornmaniac8 at 07:32 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Great work, SkS team!
One complaint I have (or perhaps just missed) is a relative lack of discussion of the No Position papers and their self-ratings.
You mentioned at the end of page 4:
"Among self-rated papers not expressing a position on AGW in the abstract, 53.8% were self-rated as endorsing the consensus."What about the other 46.2%? Needless to say, it would somewhat undermine your conclusion if of the No Position papers that were self-reviewed, the entire remainder rejected the consensus. Now, I'm 99.9% sure that wasn't the case, but unless I missed it, I don't see any further discussion of the self-reviews of the No Position papers.
Could an author perhaps provide some additional insight to go along with that 53.8% figure? Of the remainder, what percentage self-identified as "rejecting" the consensus, and what percentage self-identified as "no position."
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gws at 06:14 AM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
The Financial Times link seems already behind a paywall, at least when accessed from here (Norway)
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miffedmax at 05:36 AM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
I haven't done a thorough search, but it sure seems a lot of the denier blogs closed their comment sections immediately after challenging the 97% claim on pretty much the same grounds as fretslider.
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dana1981 at 05:00 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Note that I tweaked the first sentence a bit to add some precision.
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DSL at 03:42 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund: "Why are the CERN physicists focusing on cosmic rays when it is correct what Jim Eager said about that there are no theories supported by the full body of evidence?"
Herrhund, the cosmic ray theory is not a comprehensive theory of climate change. It is not an alternative to the theory of anthropogenic global warming. If Svensmark turned out to be right about cloud seeding, CO2 would not suddenly stop absorbing/emitting radiation at various pressure-broadened bands in the thermal infrared range. You also fail to understand what's working against Svensmark. That, in fact, strongly suggests that you're not concerned with scientific progress but rather finding anything (no matter how collectively incoherent) that supports your current understanding of the world.
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DSL at 03:34 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Otiose: "It's very possible in a decade or two science historians will cite this paper as an example during the period in question measuring the degree to which politization was successful in defending a parituclar view or set of views in the climate field and not a measure of the validity of the science."
Yes, Otiose, it is possible. Now, tell me how probable it is, and give me the evidence upon which you base your answer. -
John Hartz at 02:45 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
The fact that two-thirds of the 12,000 papers reviewed did not explcitly mention endorse "climate change" or "global warming" completely undercuts the denier meme that scientists have adopted pro-AGW positions in order to feed at an imaginary grant trough.
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MA Rodger at 01:40 AM on 19 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
With my memories of the heavy-going I encountered discussing the more straightforward issues raised in part 1 of this post, this second part would appear a nightmare.
One of the areas I consider worthy of discussion is the reconstruction of the past AMO. Tom Curtis has already addressed some aspects of this up-thread.
The existence of an AMO prior to the industrial age would give much credence to the Tung & Zhou 2013 thesis. But I find the offered analysis, the statistical significance identified between CET & Mann et al 1998 RPC#5 data, to be less than convincing. The wavelet analysis on CET will yield a 50-80 year signal of some sort, just as the Mann et al filtering will yield a 50-90 year signal. And as there are such signals existing in synchronisation in both the AMO & the CET for the last 130 years, it would take very little for them to stay in synchrony for a further 200 years into the past. So why is this 50-80 year cycle in CET more than just a form of cherry-picking?
Mann et al 1998 is not the only extended AMO reconstruction. Gray et al 2004 present an AMO reconstruction 1567-1990 which certainly looks more convincing that Mann et al 1998 when compared to Enfield et al 2001. Gray et al 2004 was noted within Tung & Chou 2013 but not seriously considered for analysis. And Gray et al 2004 shows nothing convincing by way of a periodic AMO that could be resulting from natural variation.
For illustration, I have plotted the Enfield, Mann & Gray AMO series here.
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Dikran Marsupial at 01:36 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Say we wanted to introduce a new brand of cat food, "Vibrizzae", and for our advertising campaign, we conducted a survey to find out whether cats preferred our catfood over that of our competitors. So we found twenty households with cats, and asked their owners to put out a bowl of Vibrizzae and a bowl of MouseChunkz for each cat at noon and then return an hour later to see which had been eaten. Eight cats were found to have eaten the Vibrizzae, two had eaten the MouseChunkz and 10 had not touched either (perhaps they were having a nap, or had gone outside hunting, or just weren't hungry). So how could we present our results? The cats that didn't eat either catfood don't really tell us anything about the cat's food preferences, so the obvious thing to analyse the food preferences of the cats that actually ate some of the catfood. We could then reasonably claim "eight out of ten owners, that expressed a preference, said their cats preferred Vibrizzae"; sound familiar?
Now the Vibrizzae Corporation could have said that "40% of owners said their cats preferred Vibrizzae", but that is clearly only a lower bound on the proportion of cats that preferred Vibrizzae as it implicitly assumes that the 50% of cats that didn't eat anything would have eaten MouseChunkz had they eaten anything. Now if you were the CEO of MouseChunkz inc. I can see why you would argue that Vibrizzae should choose the latter advertising slogan, but would that have been fair or reasonable? No, of course not, it would clearly be a daft request, and the CEO of the Vibrizzae Corporation would laugh his arse off if the CEO of MouseChunkz inc had made any request of the sort.
In case anybody has missed the analogy, the skeptics that are claiming that there is not a 97% concensus are making the same argument as the CEO of MouseChunkz inc. and their argument is about as sensible. "In our survey 97 out of 100 papers who expressed a preference, said their scientists preferred anthropogenic climate change" is essentially what the survey says.
Of course, like all analogies, you can almost guarantee that someone will extend it beyond reason to avoid the basic point being made, but at the very least it establishes a precedent for the calculation used. ;o)
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Otiose at 00:58 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
It's very possible in a decade or two science historians will cite this paper as an example during the period in question measuring the degree to which politization was successful in defending a parituclar view or set of views in the climate field and not a measure of the validity of the science.
Moderator Response:[DB] Please note that evidenceless posturing adds only noise to this discussion. Comments containing only noise will be removed.
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KR at 00:54 AM on 19 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund - "What I am trying to say here is, that throwing around with headlines like '97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature' is not accurate since they are missing all literature in other languages than English, as well as all research papers which are not using the exact key words."
Indeed, some skeptic papers were missed by those by criteria. But for those same reasons, so were many papers supporting the consensus. This is a sampling procedure, looking at a representative subpopulation and extrapolating to the whole, with small uncertainties due to sample size and how representative a slice of the population was examined.
12,000 papers is a huge sample - political studies with +/-3% accuracy are commonly done with <1000 samples. And I would opine that 'global warming' and 'global climate change' will produce a quite representative slice.
This is a percentage study of a population to measure consensus - and given the data, it's missed some 44 consensus papers for every single skeptic paper not collected by the search criteria. Whether or not it collected your favorite (individual) paper(s) is irrelevant; your argument is invalid.
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Tom Curtis at 00:26 AM on 19 May 2013Measure the climate consensus yourself with our Interactive Rating System
Kevin C @12, well picked. The "missing" paper from an "e" search turns out to be:
Agricultural Impacts Of Global Warming - Discussion
Authors: Innes, R; Kane, S (1995)
Journal: American Journal Of Agricultural Economics
Category: No Abstract
Endorsement Level: 4. No Position -
Dikran Marsupial at 00:23 AM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
I have also deleted my responses to fretsliders deleted posts. If fretslider wishes to discuss the issue in a less argumentative manner, I would be happy to start again from a clean slate.
Moderator Response:[JH] Thank you.
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Kevin C at 00:14 AM on 19 May 2013Measure the climate consensus yourself with our Interactive Rating System
I can't imagine an abstract with no e's, unless someone was having a bet. A paper with no abstract and no e's in the title might be the case.
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John Hartz at 00:11 AM on 19 May 20132013 SkS News Bulletin #12: The Consensus Project
fretslider:
Many of your recent posts are in violation of the following part of the SkS Comments Policy. As such, they have been deleted.
Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.
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Tom Curtis at 23:16 PM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
JosHaq @10, not knowing how to search for wildcards, I merely searched for "e" with essentially the same results (12279 total abstracts). The difference between that and the 12,465 papers recovered by the ISI search according to the paper would indeed be the 186 non-peer reviewed papers. (Or at least that seems very likely.) I have no explanation for the difference between the wildcard search and my "e" search (unless there is an abstract with no "e"s), nor why the difference in the total papers between search engine and paper.
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Tom Curtis at 22:58 PM on 18 May 20132013 SkS News Bulletin #12: The Consensus Project
fretslider @8:
To believe means "to accept something as true". So according to you, athiests accept nothing as true. (I wonder if you accept it as true that atheists accept nothing as true? Or was that merely a convenient lie that you did not believe.) Anyway, however much that idiocy may be true of you, it is not true of atheists in general - so don't slander us with your ill concieved misunderstandings.
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Tom Curtis at 22:51 PM on 18 May 20132013 SkS News Bulletin #12: The Consensus Project
fretslider, you are not being imaginative enough. Consider the paper, "First evidence of Late Carnian radiolarians from the Izmir–Ankara suture complex, central Sakarya, Turkey: implications for the opening age of the Izmir–Ankara branch of Neo-Tethys". It neither directly nor indirectly affirms that humans are causing climate change, and wasn't even included in the survey. Against the backdrop of all scientific publications, papers actually discussing the issue of whether humans have caused global warming are distinctly less than 1%; and hence the 97% of papers discussing the issue who affirm that humans are in fact causing global warming are also less than one percent. There is no limit to how much you can pad the statistics to avoid an uncomfortable truth. You can include newspaper articles as well. Or add in right wing think tank press releases. But no matter how you pad and how you evade, it will still be true that:
97% of scientific papers that discuss the issue affirm that global warming is caused by humans.
The evident desperation of deniers to conceal that fact shows just how strongly they rely on subterfuge to make their case. -
JosHagelaars at 22:50 PM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
@Tom Curtis #9, the total number of papers in the search option is 12280 (enter SQL wildcard % at 'Search Term') and before I start a search it says that 12,464 papers are present. So, you are probably right that (almost) all the papers have been retained in the database. The difference between the two numbers is 184, almost the same as the 186 you mention. A coincidence?
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jyyh at 22:37 PM on 18 May 20132013 SkS News Bulletin #12: The Consensus Project
fretslider - it seems you're the sort who thinks if one forgets gravity one can fly. Thus, you might also believe the rocks have a mind which is constantly thinking of gravity. This is an interesting belief system, but please talk about this somewhere else, do you know a forum for pantheism which would be in my opinion a more proper place to discuss your beliefs about rocks whichi have not stated anything to you unless you hear them speak? (possible ad hom - delete if required)
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