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Tom Curtis at 22:34 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund, two can play that game.
"Sensitivity of a global climate model to an increase of CO2 concentration in the atmosphere" by Manabe and Stouffer (1980) was not included because it was published too early for the survey, even though it clearly affirms anthropogenic global warming (IMO).
"Thermohaline Circulation, the Achilles Heel of Our Climate System: Will Man-Made CO2 Upset the Current Balance?" by Broecker (1997) was also excluded due to lacking the correct search terms although it also affirms AGW.
By its nature, not survey of the contents of scientific papers can be expected to be exhaustive; but any large survey is likely to be representative unless it uses biased search terms. This survey did not.
Of course, you can disprove my assumption that the survey was not biased by its search terms by conducting several different surveys of comparable size using distinct (and independent) search terms; or by one very large survey using a random selection of articles from the entire scientific corpus. But just identifying single papers that were not included proves nothing. For all you know, for each "skeptical" paper not included, there are 100 affirming papers that were not included and of which you are unaware.
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Dikran Marsupial at 22:18 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund, yes, please do research, but bear in mind that it is generally best to do the research before posting.
Asking whether the database contains all debunkings is yet another attempt at rhetorical evasion on your part. It is irrelevant to the purpose of a study whether the paper is a debunking or not, so there is no need for me to check. The point was that there are plenty of non-skeptic papers that are not included due to the choice of keywords as well, that you were not taking into account. Pointing out the debunking papers was just an easy way of demonstrating that this is the case.
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Tom Curtis at 22:07 PM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
JosHag @8, the total number of endorsement papers on the database exceeds the numbers mentioned in the paper as well. Combined there is an excess of 335 papers. Interestingly in the consensus project paper, it says:
"The ISI search generated 12 465 papers. Eliminating papers that were not peer-reviewed (186), not climate-related (288) or without an abstract (47) reduced the analysis to 11 944 papers written by 29 083 authors and published in 1980 journals."
There were a total of 335 "not climate-related" and "no abstract" papers, suggesting these have been retained in the data base we are searching.
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herrhund at 22:01 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Well, okay I will leave - doing some research though.
I don't know if you notices, English is not my first language so yes indeed, sometimes I oversee text which is not written in my mother language for some reason.
However, it does not change the facts I pointed out. And you did not answer my question since you expected me to check my sources too, I thought you checked yours in case some of them were debunked. -
fretslider at 21:59 PM on 18 May 20132013 SkS News Bulletin #12: The Consensus Project
97% sounds very impressive.
Yet why did the original press release say: "From the 11 994 papers, 32.6 per cent endorsed AGW, 66.4 per cent stated no position on AGW, 0.7 per cent rejected AGW and in 0.3 per cent of papers, the authors said the cause of global warming was uncertain."
How did you get from 32.6% to 97%
Moderator Response:[Dikran Marsupial] This is explained in detail in a previous post here.
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Dikran Marsupial at 21:50 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund, stop playing games, I was merely pointing out your lack of self skepticism. The debunkings I mentioned were clearly listed on the web page that you yourself provided, but you failed to mention them. This means that either you saw them and chose not to mention them (which would be dishonest) or that you stopped looking when you found the evidence that supported your argument and didn't bother to check it out (which would suggest that it is you that is biased). Being charitable, I shall assume it is the latter.
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jyyh at 21:43 PM on 18 May 20132013 SkS News Bulletin #12: The Consensus Project
Congratulations, it was nice being a part of the initial information gathering phase. Very clever of you to make it a sort of game among the site. :-). I never imagined seeking contact info from thailand in thai language, contact info of female scientists who have published only by their maiden name, or trying to find contact info from indian (or US) nuclear facility, let alone among the russian academics. I will probably remember the game long afterwards. Did you ever find out which T.Hong (or what the name was in the chinese universities) made which paper??
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herrhund at 21:41 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Did you check all papers which count to the 32% with position on AGW if they got debunked somehow?
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Dikran Marsupial at 21:38 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Herrhund, your argument is incorrect, unless you have some reason to suggest that English speaking scientists are more biased in favour of AGW than against. You have provided precisely zero evidence to support that contention. Similarly the exact choice of keyword is irrelevant unless you can show that the particular keywords used were biased towards AGW. It is not feasible to surver every single paper ever published, so we have to have some method of generating a representative sample. Pointing out skeptic papers that were missed is not evidence of bias, especially if your examples includes papers that were debunked in the peer reviewed litterature and the debunkings are not in the database either!
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Dikran Marsupial at 21:34 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund, there are also many papers not included in the project beacuse of missing keywords that do at least implicitly supprt AGW, I know this because I am one of the authors of one such paper! Pointing out skeptic papers that were not included does not establish there was a bias unless you can show that it disproportionately favours mainstream over skeptic papers. So please stop disrupting the discussion until you can do so.
Note that in the particular case of the Svensmark and Friis-Christensen paper, there is clearly no bias as the database doesn't contain the article by Gierens and Ponater that debunks Svensmark and Friis-Christensen either. Or the one by Jorgenson and Hansen. Funny you didn't mention that (it isn't difficult to check whether comments papers are published pointing out the flaws in existing papers).
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herrhund at 21:31 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
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. And I can bring up tones of research papers like that - all peer reviewed.
Fine, there is a lot of evidence that the climate change is driven by humans - there is also a lot of evidence that support other hypothesis and theories. There is also something like False consensus effect. existing. -
herrhund at 21:23 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Another study that is not included in the consensus project because of missing key words in the abstract:
'Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships'(Henrik Svensmark, Eigil Friis-Christensen
Solar-Terrestrial Physics Division, Danish Meteorological Institute, Lyngbyvej 100, DK-2100; published 1997) -
Dikran Marsupial at 21:20 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund, your evasion is transparent. You have made it abundently clear that you are unwilling to discuss the information the CLOUD project has published, which is a fairly good indication that either you know it doesn't really support your argument or that you don't actually know what it says and are just playing rhetorical games to avoid the fact that those who reject the existence of AGW are only a tiny minority within the scientific community - which is the topic of the discussion.
The CLOUD people were making the same kinds of noises to the general public before the last publication, but the science itself turned out to be a damp squib. I wish they were right, it would be great news, but I am rational enough to know that is highly likely to be wishfull thinking.
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herrhund at 21:04 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Dikran,
the last publication from the cloud project is from august 2011
http://cloud.web.cern.ch/cloud/People/Publications.html
If you would understand German, the interview link I posted is from may 10th with the leading researcher of the cloud project. He is saying that they are going to release new research results, LATER this year - and it is going to be interesting. -
Dikran Marsupial at 20:29 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund the CLOUD project has published the results of some of their work already, so there is no problem in discussing it. The fact is that it doesn't support your argument and that you simply don't want to discuss it, that is not the same as not being able to discuss it.
I suspect that there are very few following the discussion that would fall for such transparent evasion as introducing an item to support your argument and then saying we can't discuss it because it hasn't been publsihed yet!
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herrhund at 20:15 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Well, I think nobody can talk about the cloud project in detail since the results are not released yet - I read an interview with the research team and at the moment the results are being checked and will be presented as soon as they are excepted.
http://science.orf.at/stories/1717291/ -
Dikran Marsupial at 19:33 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
herrhund - the CLOUD project at CERN is a bad example for your argument, there results are interesting, but don't actually support a strong link between cosmic rays and climate. This was something that was pretty well known already, but it does show that governments are happy to fund climate skeptic scientists if the quality of the proposed experiments was high (which AFAICS they were - the results provided so far have been interesting, but not for the reasons the skeptics hoped).
As for the paper in German, I suspect the reason it wasn't included is that it clearly isn't a journal paper. The fact it was published in January of this year is another good reason.
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herrhund at 19:20 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Another example of a research paper, that could not find a way in this study because it is German.
http://wkserv.met.fu-berlin.de/Beilagen/2013/SO%2001-13%20Klimawandel%20Europa.pdf
This paper shows for example a significant correlation between the middle temperature in Europe and the number of sunspots since 1672. -
herrhund at 19:13 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
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?
The cloud experiment is going to release their research results this year, but here is some information for now:
http://home.web.cern.ch/about/experiments/cloud -
herrhund at 19:01 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
"Jim Eager at 07:14 AM on 18 May, 2013
Herrhund wrote: "there are other theories"Except that there are no other theories.
There are several hypotheses, most of which have already been disproven, such as "it's the sun," or shown to be insignificant, such as cosmic rays, but none have risen to the level of being a cohesive theory supported by the full body of evidence."
What about papers done in other languages than English?
Or paper which are about that exact topic but not having the key words in their abstract?
An example: 'Impact of galactic cosmic rays on Earth’s atmosphere and human health' A.Singh, D. Siingh, R. Singh;
The abstract of this paper does not use the key words - so I believe this research paper was not included. Just naming one example of a research paper that is ignored by this study. -
JosHagelaars at 18:41 PM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
Thanks a lot for the search possibility.
I tried to check the total number of papers in Endorsement Level '8. Undecided', but got no matches. Endorsement Level 4 'No position' gives 8269 which is much higher than the 7930 mentioned in the Cook et al paper.
Are the level 8 papers per accident incorporated in the level 4 papers? -
Dikran Marsupial at 18:18 PM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Dr Tung writes: "That model spread is rather large. If you are satisfied with that, that is fine with me."
The model spread is indeed large, the key question is whether there is a good reason to suppose that the spread should be smaller, and you so far have provided no evidence or argument to suggest that it should. Of course we want the projection to have as great a certainty as possible, so none of us are "satisfied" with the spread and why climate modelling groups are working hard to improve their models.
"And I am not sure how the models can be made to do it since we do not know the initial condition in the ocean sublayer well in 1850-1870 (the time these model simulations start)."
That is the entire point of using a Monte Carlo simulation. We can't predict chaotic phenomenon, but we can simulate them, so that is what we do and the spread of the model is an indication of what is plausible given what we know about the underlying physics.
"My comments about the CMIP3 model underpredicting the warming should not be taken as a criticism of the models"
In that case, I think you need to be more careful in how you express yourself as there are those in the public debate on climate that are likely to use your words to argue that the models are flawed. The statement however is still wrong - the models DON'T underpredict the warming, the ensemble mean IS NOT a hindcast of the observed climate change, only the forced component. The enembles hindcast of the actual climate is that it lies somewhere in the spread of the model runs, which indeed it does, so the models DO NOT underpredict the warming. I'm sorry to go on about this, but this is a fundamental point in understanding what the model ensemble actually says.
"One could take the point of view that the internal variability is just climate noise, and that the difference from any such unpredictable (by models) internal variability should be considered as "insignificant" (p595 of AR4) (post 33 here)"
It is only insignificant for the purposes of deciding whether the models do what they are intended to do correctly, which is to hindcast/project the forced component of the climate change.
"This is in essence a statement that we will ignore internal variabilities just because we have not found a way to simulate it using the current generation of models."
This is a deeply unfair and uncharitable characterisation of a community of hard working scientists. In making policy for (in)action on fossil fuel use, the key question is what is the effect of fossil fuel emissions on future climate. The answer to this question depends only on the forced component of climate change. This means the modellers are giving the direct answer to the question posed. They are not ignoring internal variabilities, far from it, the spread of the model runs is a good way of characterising the plausible effects of internal variability (according to our current understanding of the physics).
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nealjking at 18:09 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
#102, grindupBaker:
Real science often progresses in ways that seem not to have been the most straightforward, from a backwards-looking perspective. The development of quantum mechanics was far weirder than that of the framework for climate science, yet that was done in thirty years. If you look at the book by Archer & Pierrehumbert that I mentioned before, you can see how the picture fell into place.
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John Mason at 15:46 PM on 18 May 2013The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia
Agnostic #26 -
The variability of sea levels back then (and for much of the time leading up to the Pleistocene Transition) was no more than +/- 70 metres. That means that in cold cycles it only got cold enough, in the worst cases, for enough land ice to form to drop sea levels some 70m and rise them back up by the same amount during the warm cycles when it melted. Quite a difference from the 125m associated with the Last Glacial Maximum!
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Kevin C at 15:18 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
grindupBaker: Yes. While fundamental controller for the climate of any body with an atmophere has always been top-of-atmosphere energy balance, we've been stuck with surface temperatures because that's all we've got for all most of the period of interest. The start dates for various records look something like this:
10,000-1,000BP: Global prooxy record
~1700: Regional instrumental record
~1850-1880: Global instrumental record
~1950?: Energy content from reanalysis
~1990s: Energy content from observations -
Philippe Chantreau at 15:17 PM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
This has been a most interesting, truly scientific debate, all too rare on blogs. I can think only of RC as another place where such discussions could happen .Not surprisingly, there is no noise about it in the denialosphere.
I understood a couple of years ago that this was the direction where SkS was heading and thus stepped down as a moderator, as I did not have the time to participate at that level, nor to qualify myself in order to do so. I think KR is pretty close to the point where he could put together his own paper. Not to put pressure on anybody :-) but it would certainly be a useful elaboration on Dr Tung's published work and in the interest of continued scientific debate and fostered understanding...
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Chris G at 14:30 PM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
Only done a handful, but surprisingly, also 100% in agreement. Hard do find something to quibble about.
Good job.
To observe the obvious, there's quite a lot of buzz on this. One thing I noticed was that the people attacking the article, are mostly not really attacking the article; they are attacking the secondary sources reporting on the article, on points that are addressed in the article itself. And, they are reduced to quibbling over semantics without at all touching the observation that researchers rejecting AGW are a very, very small minority.
The "Peer review process was corrupted" zombie appears to be a bit more animated than normal. Yeah, either there has been a multi-national, multi-decade, coordinated effort to keep dissenting views from being published (nevermind the fame that could be had for successfully overturning established science, and being the journal in which it was published), or it is very difficult to write a dissenting article without the article containing egregious flaws.
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grindupBaker at 13:37 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
I think it's unfortunate that scientists didn't put this forward 40 years ago or whatever as "Global Warming" being an increase in the ocean heat content and hold hard onto that through the decades before discussing all these complex, though important, matters of climate change, global average surface temperature anomalies and so on. They've confused the heck out of the general public by pretty much stating it backwards.
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Tom Curtis at 13:25 PM on 18 May 2013The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia
Agnostic @26:
1) Keeping CO2 to 450 ppmv peak concentration requires reducing CO2 emissions linearly to zero emissions in 2050. It is technically and economically feasible to do. There is, however, substantial doubt as to whether it is politically feasible, ie, whether the nations of the world can be persuaded to agree to and then impliment such a program.
2) With a 450 ppmv peak concentration the natural draw down of CO2 will reduce the CO2 concentration to about 365 ppmv over 200 to 400 years. (My earlier lower estimate was in error, for which I apologize.) With an Earth System Climate Sensitivity of 4 C per doubling of CO2, that works out to a long term temperature increase of 1.5 C above the preindustrial average. That is comparable to the 1.4 C transient climate response to 450 ppmv. The net effect is that tempeartures will stay approximately constant with zero net emissions because the slow feedbacks will be countered by the gradual decline in CO2 levels from natural uptake.
3) This optimistic scenario depends essentially on our in fact reducing net anthropogenic emissions to zero in the short term, and maintaining them at zero of slightly negative values in the long term. It is optimistic only in the sense that if we make a concerted effort to tackle climate change, we can limit the disaster to levels comparable to previous experience (ie, somewhere between the economic impact of the 1970s oil shock and a permanent great depression). Absent that effort the impact will be equivalent to a permanent great depression or worse.
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paulhtremblay at 13:14 PM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Otiose: You claim "The funding for climate science has been channeled by many governments since at least the early 90's (especially true in Europe) specifically towards those scientists concerned about climate i.e. probably already predisposed towards concluding that humans were the cause if not the primary cause."
This claims is illogical for a number of reasons. First, you offer no evidence that in fact scientists who choose to study climate are predisposed to concluding that humans cause warming. It can just as well be that people who study the climate see the evidence and come to the same conclusion that CO2 causes warming, the way a biologist concudes humans evolved from other species.Further, you don't show that publishing papers questioning AGW would ruin a scientist's career. In fact, good research that overturn the consensus would make that scientists a rock star among his peers, a true innovator.
But more importantly, the whole idea that funding somehow causes bias shoud be dismissed out of hand. If we want to accept your argument, then we should also reject any biologists' claims about evolution, or any medical research--after all, most of such research comes from the government. Do engineers have a bias that objects fall at 32 ft/sec squared because they attend publich universities, funded by the government? Likewise, if a car company invents a super effecient car that gets 200 miles to the gallon, and produces the car so that everyone can test it, does that mean we shoudn't believe the car gets 200 miles to the gallon because the funding came from a car company? At the same time, if a private organization which is agains global warming funds scientists who truly produce papers overturning the consensus, do we accept thier finiing or reject them because of the funding?
Given your logic, we should not conduct any inquiry, but should act like medieval thinkers, identifying ourselves with tribes, and dismiss the ideas of other tribes not our own.
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KeenOn350 at 11:58 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Kudos to the whole SkS team for this effort
DaveW
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KR at 11:56 AM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Looking into this subject a bit further, I would like to point out Ting et al 2009, Forced and Internal Twentieth-Century SST Trends in the North Atlantic as a recent work that summarizes a great deal.
This paper examines the various components in the AMO using Empirical Orthogonal Function (EOF) analysis, which is a principal components analysis including both time and spatial patterns. They find that EOF analysis supports detrending North Atlantic sea surface temperatures using either global sea surface temperatures (SSTs) or global mean temperature, not a linear detrending, as linear detrending aliases external forcing into the AMO index.
FIG. 2. (a) The linear trend (solid black line) and detrended NASSTI (shaded). (b) NASSTI regressed onto the global mean SST (SSTg regression, solid black line) and the difference between the observed NASSTI shown in Fig. 1 and the SSTg regression (shaded). (c) NASSTI regressed onto the global mean surface temperature (Tg regression, solid black line) and the difference between the observed NASSTI shown in Fig. 1 and the Tg regression (shaded).
This supports works such as Trenberth and Shea 2006, with rather more numeric backing; the first EOF component dominating:
This first EOF explains 55%–72% of the total model variance except the GISS-EH model, which only explains 37%. However, the second mode explains only 3%–6% in all models. This indicates that on decadal time scales, the externally forced variability can be represented rather decisively by a single, globally synchronous pattern.
Note that the mid-century AMO is supported as a real, internal variation - but at end of the 20th century a linear detrended AMO is heavily aliasing global warming. This indicates that, rather than the AMO presently being at a peak influence and perhaps about to decline, it instead has the possibility of rising over the next few decades increasing North Atlantic temperatures above that driven by external forcings - whether the AMO increases or reverses in the near future will have a significant effect on Atlantic region temperatures. And the late 20th century AMO influence is actually quite small.
I would be very interested in what external forcing vs. internal variation analysis would conclude regressing against a more accurate AMO index. But I repeat that a linear detrending is inappropriate, aliases the global warming signal, and (in context with respect to the Tung et al paper) linear detrending leads to a significant underestimation of external forcings.
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KeenOn350 at 11:43 AM on 18 May 2013The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia
Excellent summary of the work by Brigham-Grette et al - and encouraging to see some learning happening in the comments section. Thanks, John
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DSL at 11:17 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Otiose, you're asking me to believe that the science is not progressive. Climate science doesn't work as you imply. It as an interdisciplinary, highly integrated, and dynamic area of research. Findings that throw doubt on fundamental understandings must explain why existing research is wrong.
Btw, your reference to the "rejected" science in the "climategate" emails works against your implied claim of fraud. If you can defend Soon & Balinuas (2003), then by all means do so, and that will get Chris Di Frietas off the hook for his years of "pal review" in the service of the Canadian group Friends of Science (an Orwellian use if there ever was one). Doing so will also reveal that the editors that resigned in protest over the publication of S&B did so based on their misinterpretation of the science.
Good luck on that. -
KK Tung at 11:09 AM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
I am trying to catch up with the replies after a busy week.
Some of the comments concern my statement that I thought there was a systematic underprediction of the observed rate of warming in the early twentieth century by the CMIP3 models. Opinions were expressed that statistically they agree within two standard deviations of the model spread. That model spread is rather large. If you are satisfied with that, that is fine with me. To me I see that the multimodel mean produced only 50% of the observed warming during the first half of the 20th century. Our proposal was that that 50% was caused by an internal variability (viz the AMO). We do not expect the ensemble mean to contain this internal variability. And I am not sure how the models can be made to do it since we do not know the initial condition in the ocean sublayer well in 1850-1870 (the time these model simulations start).
I agree entirely with Bob Loblaw in post 39. The observed climate is one realization of many possible climates. It is important to point out that one realization should in principle contain a particular phase and amplitude of the AMOC, an internal variability. There was a warm phase in the first half of the twentieth century. It is not reasonable to expect the model ensemble to produce it. Also, even if we use a single model realization, that realization may contain a different AMOC phase. My comments about the CMIP3 model underpredicting the warming should not be taken as a criticism of the models; they are expected to robustly generate only the forced solution. But the point remains that there is another part that is important but was not simulated.
One could take the point of view that the internal variability is just climate noise, and that the difference from any such unpredictable (by models) internal variability should be considered as "insignificant" (p595 of AR4) (post 33 here). This is in essence a statement that we will ignore internal variabilities just because we have not found a way to simulate it using the current generation of models.
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John Hartz at 10:57 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
@otiose #93:
You assert,
"Finally, for a few decades it's been common knowledge that any scientist who was known to be contrary to the emerging "consensus" had something less than a snowball's chance in hell of getting hired into the faculty of a major university."
Where exactly does this "common knowledge" come from?
'
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yocta at 10:44 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Is this an appropriate analogy?
Lets suppose 100 medical science papers were searched for the words lung cancer?
Now if 100 abstracts were returned and (Using Kevin C's approach):
Address the question, smoking is a cause of lung cancer (32.6%)
Address the question, don't know the answer (0.4%)
Address the question, smoking not a cause of lung cancer (0.7%)
Don't address the question (66.4%)It would be silly based on these responses to even argue that 66% of scientists consider smoking not a cause of lung cancer.
(obviously there are other causes for lung cancer...but this was a back of an envelope kind of thing)
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KK Tung at 10:19 AM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
I am glad that it (inserting a figure) works this time!
This figure was done following Bart Verheggen's prescription of removing the usual solar, ENSO and volcano influences, but not the AMO or anthropogenic influence, because we don't know what the latter is.
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KK Tung at 10:16 AM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
Could someone tell me how to insert a figure into the comment the correct way? Thanks.
Also in reply to post 53: "The Lean and Rind analyses would make me think there would not be a substial influence of such cyclical behavior, but that's worth investigating with newer data". This was done with the old and also with the new data. See my post above. The point is: if you just look at the anthropogenic response from the assumed regressor, it would show accelerated warming after 1978. But the residue has a negative trend after 1978. When that negative trend is added back to the regressed response, the combination becomes more linear.
Here is another try for post 54 with a pdf figure:
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nealjking at 10:06 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Otiose,
Science is conducted by human beings, and is heir to the weaknesses of human beings.
Nonetheless, science has managed to overcome the confines of Galilean/Newtonian mechanics to understand relativity; the confines of "realism" to create quantum mechanics; and many other discoveries and inventions that were originally undreamt of.
The way science is done in climate studies, including control of access to publication of articles, is not different from the way it is done in other sciences.
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nealjking at 10:00 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
#89: grindupBaker at 07:40 AM on 18 May, 2013
A very good collection of papers on the topic is:
The Warming Papers: The Scientific Foundation for the Climate Change Forecast,
by David Archer and Raymond Pierrehumbert
It's not a cheap book; you might be able to find it at a local library.
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Dikran Marsupial at 09:52 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
otiose, government funding is spent on plenty of climate skeptics, for instance Roy Spencer, who apparently gets all his funding from government sources and Henrik Svensmark, who according to his book "the Chilling Stars" appears to have much less trouble getting government funds than most. Or the CLOUD project at CERN, 12 million euro is a lot of money. Just because skeptics say they can't get funding, or get their papers published, doesn't mean it is actually true.
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Otiose at 09:45 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Nice study. However, there are several factors that are not included in the scope of the study that undermine its target conclusion and these relate to what's not in the papers reviewd.
The funding for climate science has been channeled by many governments since at least the early 90's (especially true in Europe) specifically towards those scientists concerned about climate i.e. probably already predisposed towards concluding that humans were the cause if not the primary cause. That would bias the pool of potential papers as scientists not interested global warming itself or of a contrary opinion would not get the funding. Other scientists in order to get funding would be incentivized (need to eat, career advancement, desire to support families, etc.) to slant their work in the preferred direction.
Moreover we know from the email release that there were important journals in the field that simply refused to accept the work of known skeptics. Another factor tending to bias the pool.
And then the peer groups selected to review submitted papers tended to be skeptical (and not in an ironic sense) toward the qualifiations and work product of any scientist who didn't lean heavily towards the conclusion that humans were the primary cause of global warming (or indeed that it exists today and did in the past). Yet another hurdle for contrary concluding papers to get through.
Finally, for a few decades it's been common knowledge that any scientist who was known to be contrary to the emerging "consensus" had something less than a snowball's chance in hell of getting hired into the faculty of a major university.
So while the study sounds good there are several factors that undermine the touted conclusion. There were at least the above factors that would tend to encourage the consensus that emerged within the published papers that had nothing to do with the underlying validity of the science or what was or was not going on within climate and had everything to do with subtle and not so subtle intimidation of one form or another targeted towards those in the field who did not conform to the party line.
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Riduna at 09:15 AM on 18 May 2013The last time carbon dioxide concentrations were around 400ppm: a snapshot from Arctic Siberia
John Mason – What an excellent article. Just how high was Pliocene and early Pleistocene average sea level compared the present?
Tom Curtis @13 expresses an optimistic view that by curbing CO2 emissions to 450 ppm (can we?) average global surface temperature will not exceed 2ºC above the pre-industrial by 2100.
I wish!
It might be, if we ignore the effects of slow feedbacks such as accelerating loss of albedo and permafrost, carbon emissions in the Arctic and increasing ocean heat content. Unfortunately we can not. Nor can we assume that CO2 concentration will not exceed 450 ppm by 2050, let alone 2100.
In the absence of enforceable national emissions targets it seems unlikely, unless there are remarkable technological developments enabling affordable carbon capture and sequestration or cheaper electricity generation from renewable sources.
Present rates of anthropogenic CO2 emissions are over 2 ppm/annum and accelerating making it very likely that concentration of 450 ppm will be reached by 2040. Emissions will continue thereafter reaching 560 ppm by 2100, resulting in average global surface temperature of around 3ºC.
It seems likely that anthropogenic emissions and those caused by slow feedbacks will result in considerably more than 560 ppm CO2 equivelant by 2100 with average global surface temperature of around 4ºC above the pre-industrial.
We should all hope that science and technology will reduce this possibility over the next 50 years. I believe they will. However there is shrinkingly little possibility that average global surface temperature of over 3ºC above the pre-industrial can be avoided this century.
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adelady at 08:41 AM on 18 May 2013Measure the climate consensus yourself with our Interactive Rating System
Hard to categorise? Yup. I studiously kept on checking that I was doing the ratings correctly. And worried that I was getting it wrong in some way or another. Now I've checked mine against the project and every single ratings number I gave was the same as theirs.
But the categories? Not hopelessly jumbled, but distinctly unwonderful in places. I'll now be using my previous scores to inform my future categorisations.
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Dikran Marsupial at 08:39 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
grindupBaker @89 In addition to Tom's answer, generally if you send an email to the corresponding author of the paper, they will be only too happy to send you a pre-print of the paper (if it isn't already self-archived on-line somewhere). This is something that most journals are comfortable with (there is an on-line database somewhere listing the practices of most journals); indeed in the old days when you published a paper in a journal they would send you a couple of dozen free paper copies of your masterpiece (as it appears in the journal) for just that purpose (which then sit in your filing cabinet for several years untill your office becomes terminally full and you put them in the recycling bin).
There is nothing that us scientists like more than to hear that someone actually wants to read our papers! ;o)
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KK Tung at 08:13 AM on 18 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
In reply to posts 52 and 53 by Bart Verheggen: Your suggestions are fair. Our work were actually following ideas similar to your suggestions.
(1) We did not assume linearity for anthropogenic forcing. In the post we used a number of nonlinear anthropogenic indices.
(2) "Another approach would be to rather than using a questionnnable (see my previous commment) estimate of the AMO as a predictor in the regression analysis, see if there is a AMO-type (or other cyclical) signal is left over in the adjkusted temperature, after having corrected for the better known influences (solar, ENSO, volcanic, anthropogenic)." This was what we did in Zhou and Tung (2013). After we accounted for your suggested better known influences, the blue line in the figure was what remains, and it shows an AMO like signal.
[image snipped]
Moderator Response:[Dikran Marsupial] Sorry, I had to delete the image as it was causing formatting problems (at least under Firefox). Please try using a URL to a copy of the image that already exists on-line.
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Tom Curtis at 08:07 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
I don't think people are giving Herhund's arguments the seriousness they deserve. Afterall, consider one of the "neutral" papers I rated yesterday. Surely it is obvious that if a paper on "Environmental Assessment Of Supercritical Water Oxidation And Other Sewage Sludge Handling Options" does not explicitly state that "Humans have caused more than 50% of global warming since 1950" then the authors must disagree with that proposition. Isn't it? Afterall, that is just part of the general maxim that "Silence is disagreement"
/sarc
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Tom Curtis at 08:00 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
grindupBaker @89, subscriptions to most scientific journals includes access to articles from prior issues on the web. Articles from periods prior to when web publication became common may not be included in this.
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Tom Curtis at 07:53 AM on 18 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
william @90, I'll bite. Just how often has the past consensus of a mature science (one with more than a million man hours of scientific research behind it) been wrong? I can only think of one instance (continental drift) and in that instance the alternative theory presented at the time was also wrong, but when a correct theory was presented it was rapidly adopted as the consensus view.
People often forget how few were the number of scientists before the twentieth century, and how limited their resources. For example, science courses (other than Mathematics) did not even exist at Cambridge University until 1851. With the small number of scientists in the past, and their limited resources, it took time to falsify promising theories. Further, most "examples" of theories that have been overturned are like Newton's theory of motion in which the overturning theory predicts the same results as the original theory withing the range of conditions in which the first theory was tested. Even today, NASA uses Newtonian theories of motion to work out the orbits of satellites and interplanetary missions.
In fact, if the history of science teaches us anything, it teaches us that once a scientific theory commands a consensus with in an area of detailed observation, any future theory will predict the same observational consequences within the resolution of current observations. So unless the CO2 concentration exceeds that of Venus, or drops near zero (the range of current observations), the history of science suggests that if any theory replaces AGW it also will predict a CO2/temperature linkage.
Further, people often forget (if they ever knew) the real bite of the argument from scientific consensus. The scientists are the experts, where an expert is somebody who knows enough about a subject not to make dunderhead mistakes. If there is a scientific consensus, then that means the vast majority of people who will not make silly mistakes accept the theory (and the exceptions all have known, strong ideological agendas, like Fred Singer who turned down a job offer from the White House because it would not allow him enough influence on policy). That means it is extraordinarilly unlikely that there is any obvious error in the theory of AGW, while obvious errors in alternative theories abound.
However, this is beside the point. Climate change deniers frequently argue that there is no scientific consensus on climate change. The need to. If they do not accept that false belief they are forced to explain why so many people who know far more about the evidence then they do, and typically are far more intelligent, accept a theory while they reject it. This article, and the paper it reports on merely shows that frequent denier claim. The frenzy with which the paper has been attacked by climate change deniers shows they know what is at stake. If this paper becomes well known and accepted, their most powerfull (and falacious) argument - that there is no scientific concensus so therefore the evidence must not be conclusive- is false.
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