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Tom Dayton at 00:47 AM on 28 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
matzdj, are you saddened by the overwhelming evidence that gravity exists? I don't know what field your PhD is in, but in science part of the definition of "progress" is that intentionally varied evidence converges on a picture of reality, because reality constrains the evidence. Scientists are motivated to show that all other scientists are wrong--that the consensus is incorrect--because that path leads to fame and personal pride and a feeling of accomplishment and contribution. So scientists leap on evidence that appears to contradict the consensus. But reality always eventually wins, as apparently contradictory evidence is refined until it reveals the truth.
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matzdj at 23:46 PM on 27 May 2013Cherrypicking to Deny Continued Ocean and Global Warming
Every time I try to review information on this site, I always come away with the sad feeling that 100% of the data interpretations that might lead to some conclusion other than anthropogenic CO2 caused Global warming are wrong. That can't be.
Both sides do have legitimate scientists on them (more on the CO2-is-the-ogre side), but there is no legitimate way that every statement that either side makes can be wrong. (-snip-).
When it comes to the escalator effect, different data sets show somewhat different effect. The GISS data that I have seen seems to show a steady average Global T from 1970 to the early 1990's, a substantial step from the early 90's to the early 2000's and a relatively steady average from then until now.
No question we are hotter now than in the 1970's (when climatologists were predicting a coming ice age), but the monotonic correlation with CO2 does not correlate, except over a long term.
If we assume that the CO2 driver is the main driver in the background, where is the analysis of all other factors that cause no net temperature climb over these relatively flat periods with step changes when the sub-drivers stop neutralizing the CO2 effect. (-snip-).
Have any of the models predicted this stair-step climb of temperature? If none do, then maybe they are missing a driver or incorrectly including it.
Is there any Experimernt, or any observation, that could occur that might lead the "settled science" folks to say, "We should look at that. We might be wrong". If there is nothing that can ever prove that your theory is wrong, than it is not a scientific theory. it is just a belief.
Some day I would like to see a fair and balanced discussion on data linking CO2 to warming and on alternative potential drivers to global warming, rather than this constant barrage of why the other guys are 100% wrong?
David J Matz, PH.D
Moderator Response:[DB] In order to make best usage of what this site has to offer, you need to use the Taxonomic listing of arguments and the Search Function (located in the UL section of every page). Discussions of the intricacies you express interest in are best conducted on those specific threads.
For example, your claims about data interpretations might be answered by reviewing the Big Picture article and following the links as needed from there.
Discussions of the Escalator and its permutations are best done here.
For CO2:temperature correlations, see here.
CO2 is not the only driver of climate
Models are not necessarily as unreliable as you think
As for your theory vs belief, I will place a separate comment about that, as a proper response lies outside the aegis of this function.
Off-topic/sloganeering snipped.
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Kevin C at 23:37 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Rob: Otto et al looks at the following temperature differences:
- mean(2000...2009) - mean(1860...1879)
- mean(1990...1999) - mean(1860...1879)
- mean(1980...1989) - mean(1860...1879)
- mean(1970...1979) - mean(1860...1879)
These are compared to the change between the two periods in either forcing or (forcing-uptake) for TCR or EffCS. The trends within those periods do not appear anywhere in the calculation. Uptake is assumed to be 0 for the early period - i.e. the ocean is assumed to be equilibriated.
There is a copy of Otto et al online here. It's worth reading what the paper actually says, because it bears little resemblence to what most secondary sources say the paper says.
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chriskoz at 19:55 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Rob@8,
I concur with your doubts. David Keith looks to me as the guy who cares about the mythical limitless growth only rather than sustainability. Not even mentioning his perpetually-moving optimism about the law of thermodynamics. I wonder why the interviewer on this YT video didn't ask for that, I would have pressed the guy here and won't let him evade it.
I think the climate change due to athmosphere being treated as CO2 dumping ground is part of even larger problem facing overpopulated earth: complete disregard on sustainabily principles by the ravaging homo "sapiens". This larger context is not to be ignored, because even if we solve/stabilise CO2 problem soon, we may end up exposing another, equally alarming environmental degradation problem.
Meanwhile it's worth remembering This article + comments, which apears to be the latest SkS stance on this topic.
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Rob Painting at 18:26 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Shoyemore - I understand one of the Skeptical Science authors has volunteered to write about the Myles Allen piece. I'm not sure how he plans to overcome the laws of thermodynamics with this carbon capture scheme. Has the hallmarks of perpetual motion machine crankery about it.
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shoyemore at 17:48 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Professor Myles Allen (one of the authors of the Otto study) has written a strange article in that rag, the Daily Mail, advocating a new departure to seriously research carbon capture and sequestration (CCS). Naturally, the Mail distorts his views in its headline (and you could almsot say it serves him right!:))
Others have been writing about this lately, like the physicist Laurence Krauss in Slate, and Dr David Keith of the University of Calgary.
www.youtube.com/watch?feature=player_embedded&v=PilKYZ_VVnc
CCS proposals like Allen's will probably used to justify more procrastination, of course.
Perhaps Skeptical Science could so a full post on this, or even re-post Allen's article for discussion. I am sure he would agree.
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Rob Painting at 17:02 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Kevin - that makes no sense. How can they calculate the transient climate response (TCR) and equilibrium climate sensitivity (ECS) without feeding in the change in (near-surface air) temperature for each period? Change in (surface) temperature is an essential input into the equation.
In figure 1 of Otto (2013) they even give a break-down of TCR and ECS for each decadal period - from the 1970's to 2000's.
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Kevin C at 15:12 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
A recent study by Alexander Otto of Oxford University and colleagues, published in the journal Nature Geoscience, also considered future global warming in the context of observations of global mean temperature change over the last decade.
I'm puzzled by this sentence, since it seems to be based on the BBC's misrepresentation of the Otto paper, rather than what the Otto paper actually says.
The Otto paper is not based on temperature changes over the last decade - in fact Otto et al totally ignore changes over the last decade (except in OHC). Instead they take the average temperature over the last decade (and also the previous 3), and compare it to the average of a baseline period from 1860-1880. And the last decade does not stand out in any way - they find similar results for the 00's, the 90's, and the 80's. This part of the calculation is trivially reproducable.
Otto et al is not without it's limitations:
- HadCRUT4 only covers 5/6 of the planet even in recent decades. My best estimate is that this causes them underestimate the temperature change by 5%, although the global temperature distribution for the 1860s is based in totally inadaquate information and so I'm guessing this number should be closer to 10%.
- They note in the text that they are calculating effective climate sensitivity, which provides a lower bound for equilibrium sensitivity. They reference Armour et al, which finds that the effective sensitivity is about 15% lower than the equilibrium sensitivity.
If correct, these two factors alone would bring the Otto ECS to 2.4C, which is much more plausible, however the EffCS-ECS correction is currently based on only one paper (and my coverage work is not published at all). Until this is better constrained I wish they would be a bit clearer about the distinction between EffCS and ECS.
The method from the Otto paper is also totally dependent on the size of the forcings. They use forcings from this paper by Forster et al which looks very interesting indeed. I would like to try this data in my response function model.
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jyyh at 13:58 PM on 27 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
ulisescervantes: "negative AO, if associated with Arctic warming, tends to mitigate the (very strong) positive feedback of extra cloudiness."
This at least goes well with the ages old weather proverb (on lake ice) from Finland that states (translation):"clear skies, strong ice, icing with snow, on ice don't go". I don't know how well this applies to salty sea ice, though.
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Tom Curtis at 13:56 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
tonyabalone @3, agreed about The Australian's publications of letters. I have never had one of my letters pointing out (even subtely) their constant misrepresentation of the science actually published. I'm now trying a new tactic. I just sent of my email complaining about the article, but copied it to David Karoly and mediawatch (mediawatch@your.abc.net.au. Perhaps the knowledge that they cannot simply disappear the email will encourage them to publish. And if not, perhaps mediawatch will take an interest.
Who knows?
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tonyabalone at 13:49 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Tom Curtis @ 2 yes I suspect that you are correct that the paper has been bombarded with complaints. I fired off an email to the editor compaining about the misinformation in the article. It won't be published of course. Limited News is very careful about their image and they don't take kindly to criticism, even when they know it is justified.
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Tom Curtis at 13:37 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
tonyabalone @1, the Australian is schizophrenic on this study. In print the headline the article "Scientists now expect 2C rise", which is doubly misleading. First because it lacks the words "at least", and second because it suggests this is news, ie, that scientists have not been expecting at least a 2 C rise since about 1990.
The then state (as you point out):
"The earth's temperature is unlikely to increase by more than 2C by 2100 - significantly less than earlier predictions - assuming carbon dioxide emissions are substantially reduced."
This contrasts sharply with the abstract of the study which states:
"This results in an increased probability of exceeding a 2 °C global–mean temperature increase by 2100 while reducing the probability of surpassing a 6 °C threshold for non-mitigation scenarios such as the Special Report on Emissions Scenarios A1B and A1FI scenarios6, as compared with projections from the Fourth Assessment Report7 of the Intergovernmental Panel on Climate Change."
(My emphasis)
The abstract does not discuss scenarios with substantially reduced emissions at all.
The in print article goes on to say:
"The results are based on a scenario in which action is taken to mitigate emissions, though no reduction target is specified. It says under a 'business as usual' approach, temperatures are likely to rise by more than 2 C."
Well, I guess 4 C (the expected rise under BAU) is more than 2 C, so it is not exactly a lie - but hardly informative.
In contrast, the online version of the Australian leads with:
"Doubt will remain on climate
BY:MITCHELL NADIN From: The Australian May 27, 2013 3:00AMSCIENTISTS have narrowed the range of possible global temperature rises due to greenhouse gas emissions, but say uncertainty will always remain because of the complexity of factors in climate change.
Research conducted at the Melbourne University, and published today in Nature, found previous estimates of a 6C rise in temperatures by 2100 were "unlikely", but that exceeding a 2C change was "very likely" given business-as-usual emissions."
Same author, same study, different title and a balanced if much truncated text. Oddly, that article is listed as being posted "1 hour ago", ie, 12:30 PM AEST, not the 3:00 AM listed under the byline. My guess is that complaints were made about the transparent and misleading bias of the inprint article, resulting it being pulled online and a better version substituted. Without, of course, any admission of error.
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tonyabalone at 13:03 PM on 27 May 2013Uncertainty no excuse for procrastinating on climate change
Sadly "The Australian " newspaper today (27 May) was up to its usual trick of misrepresenting the science by stating in the opening sentence "The earth's temperature is unlikely to increase by more than 2C by 2100.." whereas the authors are clearly saying that "exceeding 2C is virtually certain." This is typical of the Murdoch press as they continually put the best face on the climate science even if it means that publishing misinformation.
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chriskoz at 11:53 AM on 27 May 20132013 SkS Weekly Digest #21
Toons are getting better and better!
I thought the one from last weeek was hard to beat but this week is also excellent. And sadlyvery realistic, as news popup about arctic drilling opportunities following receding ice.
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Tom Dayton at 09:54 AM on 27 May 2013Has the rate of surface warming changed? 16 years revisited
I agree with jdixon1980 and Dumb Scientist: Why the heck do climate scientists refer almost exclusively to atmospheric temperature with the words "global temperature" in press releases, interviews, and even sometimes abstracts, without an emphasized disclaimer that atmospheric temperature is not even remotely close to the real global "temperature"--that is, total thermal content? Often the scientists even say publicly that "global warming has slowed" or "paused" or is on "temporary hiatus" when they know perfectly well that it most certainly is not when you properly consider the total energy content.
I asked that of James Hansen last week in his talk at NASA Ames Research Center, but I did not phrase the question clearly enough. He answered that you do not even need to do that, because even surface atmospheric temperature has not paused in its increase; it has merely not been increasing as much as it was in the decades before, and that is entirely expected variability. I think that retort is too technical for most of the public. I think it is much easier for the public to understand that the "temperature" of the entire system must be what is monitored, and clearly it has not stopped increasing. (By the way, Hansen's talk is available online on UStream.)
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Tom Dayton at 09:15 AM on 27 May 2013It's not bad
New NASA study accepted by Geophysical Research Letters (Lau et al.) quantifies that wet places will get wetter and dry places will get drier--more floods and drought. Heavy rain will increase, light rain will increase slightly, but moderate rain will decrease and no rain will be more frequent. There is a summary with video of global map of changes.
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Steve J at 08:10 AM on 27 May 2013Ivar Giaever - Nobel Winning Physicist and Climate Pseudoscientist
Needs a place on the page "Climate Misinformers"?
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Dumb Scientist at 02:27 AM on 27 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
I wanted to thank Dikran again for his contribution. It inspired my own simulation, which has better formatting here.
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ulisescervantes at 20:11 PM on 26 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Excellent article, thanks. Yet, I wanted to note something: arctic clouds during fall-winter-spring have a net heat-trap effect. At the same time, these periods of very negative AO, that happened in recent years between fall and spring, are synonymous of sustained high pressure (and correct me if I'm wrong, cloud-free skies) over the Arctic. It sems that negative AO, if associated with Arctic warming, tends to mitigate the (very strong) positive feedback of extra cloudiness. Any thoughts?
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garethman at 18:31 PM on 26 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
What a cracking good article. It clerared up a lot of questions I had regarding this issue, especially due to living in Wales where the jet stream almost rules our lives.
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Bernard J. at 13:58 PM on 26 May 2013On the value of consensus in climate communication
Anyone who has any doubt about the practical utility of Cook et al should consider that the Australian conservative opposition leader, Tony Abbott, has used ambiguity about a scientific consensus to publicly question the very existence of climate change. Many of his senior (and junior) party members, and a number of high-profile conservative media commentators, are even now at least as inclined to use this stratagem to stir up public doubt.
This action was one of several that were employed by conservatives and that led to a very significant delay of action in Australia in addressing the effects of human emissions. It has in fact effectively tainted the political landscape of Australia since 2010, when its consequences amongst the general public contributed significantly to Kevin Rudd shying away from action and Julia Gillard grasping the reins from him.
The next (and already evident) approach by the conservatives will be to acknowledge that climate change is happening, and that it was accepted by a consensus of scientists, but that it is not nearly as dangerous as scientists are warning. It's just the next gambit in the list of denialist responses that many of us have been discussing for years. A useful follow-up to Cook et al would be to conduct a similar survey investigating scientific understanding of and thoughts on the full spectrum of consequences and impacts of human-caused climate change. Last year in an idle moment I even sketched an outline for such a survey, including questionaire design and methodological rationale and approaches such as stratification for professional and personal cofactors.
Now that would be a study that would be of great interest to me, and no doubt to many others...
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KK Tung at 13:43 PM on 26 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to KR at post 83 and originally at post 14 on the Anderson et al 2012 paper: It was claimed by KR that this paper has ruled out the possibility of more than 10% of the observed warming as contributed by natural variability. I am delinquent in replying to this thread.
Nothing of the sort--- that sets an upper limit of 10% as contributed by natural variability as claimed--- can be concluded from the model results.
Unlike the papers of Meehl et al that I discussed in post 113, the models used in Anderson et al are atmosphere-only, and are incapable of generating internal variability involving ocean dynamics. Through clever experimental design, the authors were able to place some constraints on the magnitude of unknown internal variability, and showed consistency within models which simulated well the observed warming of the late 20th century as almost entirely forced. In the first simulation, the observed sea-surface temperature (SST) in 1950-2005 is specified but with no greenhouse gas forcing or any other atmospheric forcing. In the second simulation, known atmospheric forcing such as greenhouse gases, tropospheric sulfate aerosols, tropospheric ozone and solar variations are added to the first. In third simulation, there is no change in SST. The atmospheric radiative forcing is the same as the second simulation. Five ensemble members are run for each experimental setup. The top-of-the atmosphere radiative imbalance is assumed to be the same as what should have been going into the (missing) ocean as change in ocean heat content. This is a reasonable assumption. The second simulation should give the radiative imbalance produced by known radiative forcing agents and the observed historical SST. This imbalance was compared with the ocean heat content change and was found to be in good agreement. The ocean heat content change was estimated using Levitus et al’s data up to 2008, and down to about 700m. It was assumed that this is 70% of the total ocean heat content, as the latter was not in the data. Possible errors associated with this one assumption alone already could exceed 10%. (This is however not my main argument.) The rest of the paper went on to argue why there is no room for more than 10% contribution from other unknown radiative forcing agents.
The model result should be viewed as a consistency test of the hypothesis proposed. As I mentioned in my previous posts, most CMIP3 models succeeded in simulating the observed warming in the second half of the 20th century as forced response using known radiative forcing agents with the magnitudes that they input into their models. If, as we argued in our paper and in part 1 of my post, the tropospheric aerosol cooling, which is uncertain, was underestimated, there would be a need for the presence of internal variability that warms during the second half of the 20th century. The authors acknowledged the possibility of two alternative hypotheses that were not tested by their work: My comments in bold below.
It should be noted that….there are two alternate, untested hypotheses. One is that the known change in total radiative forcing over the last half of the twentieth century … is systematically overestimated by the models (yes, that is our hypothesis) and that the long-term observed changes in global-mean temperatures are instead being driven by an unknown radiative-forcing agent(the unknown agent is the additional tropospheric sulfate aerosol cooling). The second hypothesis is that the global-scale radiative response of the system … is systematically underestimated by the models (equivalently the climate sensitivity is systematically overestimated) (I do not intend to argue that the climate sensitivity should be lower than used by the models, and so this is not the hypothesis that we pursued)…. However, for either of these two alternate hypotheses to supplant the current one (i.e., that known historical changes in total radiative forcing produced the observed evolution of global-mean SSTs and ocean heat content), the unknown forcing agent would need to be identified(we have identified it), changes in its magnitude would need to be quantified (we have not done it yet but showed what it needed to be), and it would have to be demonstrated that either (i) changes in the magnitude of known forcing agents in the model systems are systematically over-estimated by almost exactly the same amount or (ii) the radiative responses in the model systems are systematically underestimated by almost exactly the same amount. (Perhaps the word "exactly" should not be used in this context). However, testing either of these two hypotheses given the current model systems is not feasible until a candidate unknown forcing agent is identified and its magnitude is quantified.
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DSL at 13:36 PM on 26 May 2013Help close the consensus gap using social media
Actually, it does very much matter why. If we know why, then we know what to expect in general. We know the trend isn't going to go into long-term reverse -- not for a very long time.
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Dumb Scientist at 12:52 PM on 26 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In my original post, I claimed that regressing global temperatures against the linearly-detrended Atlantic Multidecadal Oscillation (AMO) to determine anthropogenic global warming (AGW) assumes that AGW is linear. Thus, even if AGW actually were faster after 1950, Dr. Tung's method would conclude that AGW is linear anyway.
Dr. Tung dismissed Dikran Marsupial's MATLAB simulation because its conclusion is "obvious" and suggested coming up with a better example without technical problems. I disagree with this criticism and would like to again thank Dikran for his contribution, which inspired this open-source analysis written in the "R" programming language.
Can regressing against the linearly-detrended AMO detect nonlinear AGW?
Imagine that AGW is very nonlinear, such that the total human influence on surface temperatures (not the radiative forcing) is a 5th power polynomial from 1856-2011:
t = 1856:2011
human = (t-t[1])^5
human = 0.8*human/human[length(t)]Its value in 2011 is 0.8°C, to match Tung and Zhou 2013's claim that 0.8°C of AGW has occurred since 1910. The exponent of "5" was chosen such that the linear trend after 1979 is 0.17°C/decade, to match Foster and Rahmstorf 2011.
Tung and Zhou 2013 describes an AMO with an amplitude of 0.2°C and a period of 70 years which peaks around the year 2000:
nature = 0.2*cos(2*pi*(t-2000)/70)
Global surface temperatures are caused by both, along with weather noise described by a gaussian with standard deviation 0.2°C for simplicity:
global = human + nature + rnorm(t,mean=0,sd=0.2)
N. Atlantic sea surface temperatures (SST) are a subset of global surface temperatures, with added regional noise with standard deviation 0.1°C:
n_atlantic = global + rnorm(t,mean=0,sd=0.1)
Compare these simulated time series to the actual time series. The AMO is linearly-detrended N. Atlantic SST:
n_atlantic_trend = lm(n_atlantic~t)
amo = n_atlantic - coef(summary(n_atlantic_trend))[2,1]*(t-t[1])
Regress global surface temperatures against this AMO index and the exact human influence, after subtracting means to insure that the intercept handles any non-zero bias:
human_p = human - mean(human)
amo_p = amo - mean(amo)
regression = lm(global~human_p+amo_p)Will Dr. Tung's method detect this nonlinear AGW? Here are the residuals:
Let's add the residuals back as Dr. Tung does, then calculate the trends after 1979 for the true and estimated human influences:
Note that the absolute values are meaningless. A Monte Carlo simulation of 1000 runs was performed, and the estimated human trends since 1979 are shown here:
Notice that even though we know that the true AGW trend after 1979 is 0.17°C/decade, Dr. Tung's method insists that it's about 0.07°C/decade. That's similar to the result in Tung and Zhou 2013, even though we know it's an underestimate here.
The linearity of the estimated human influence was measured by fitting linear and quadratic terms over 1856-2011 to the same 1000 runs. The same procedure applied to the true human influence yields a quadratic term of 5.965E-05°C/year^2.
Even though we know that the true quadratic term is 5.965E-05°C/year^2, the average quadratic term from Dr. Tung's method is less than half that. The true nonlinearity of this AGW term is 5th order, so this is a drastic understatement.
Conclusion: Tung and Zhou 2013 is indeed a circular argument. By subtracting the linearly-detrended AMO from global temperatures, their conclusion of nearly-linear AGW is guaranteed, which also underestimates AGW after ~1950.
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user6244 at 12:38 PM on 26 May 2013Help close the consensus gap using social media
My earlier post got deleted.
I am trying to point out why it doesnt really matter what is causing the climate to change.
Instead we need to focus on methods to turn it around if the dire predictions are correct.
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user6244 at 12:25 PM on 26 May 2013Renewable energy is too expensive
let me try again.
Alternative energy is expensive bottom line it doesnt matter what is or isnt accounted for in the price. When I whip out my wallet I dont care how the price got to where it is at. At this moment in time if i come to the counter for a box of solar or a box of fossil fuels especially natural gas at the moment the cost of gas is far cheaper , no way around it.
I would like to link to an article that does a better job of making the point Energy policy and Environment
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nealjking at 10:36 AM on 26 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
The point of the paper is that the state of the current scientific literature reflects an overwhelming working assumption by relevant scientists that AGW is real and happening; and that, unfortunately, the impression of most Americans (for example) is that the scientific community is in a state of conflict about the matter.
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Ken in Oz at 10:29 AM on 26 May 2013On the value of consensus in climate communication
Correction to para 3 of my comment above - "Whilst this effort to examine the consensus amongst scientists is important and valuable..."
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Ken in Oz at 09:44 AM on 26 May 2013On the value of consensus in climate communication
Good comments! Definitely worth drawing attention to the strength of agreement amongst scientists but it does sound like careful consideration of the language used is necessary, so better call it something other than a scientific consensus!
Is it of any value to put the 3% under the scope -or would that simply give them a platform in which the "stick to the facts and don't leave out the provisos" scientists will face opponents that have impose no such restrictions or boundaries on their rhetoric? Against the experienced debater, who can argue as effectively that black is white and that 2+2=5 as argue the contrary, we need experienced debaters who can enter the fray, boots and all.
Whilst this effort to examine the consensus amongst scientists, I think what I would like to see is more effort along a different tack - a greater focus on our peak science bodies and on the role they have played in providing independent expert assessment of climate science, it's methodology and results.I'd like to see a starting from scratch rerun of that process, but with as much televised fanfare as possible - a look at the Royal Societies and Nation Academies, what and who they are and what they do, who picks the panels/committees and on what basis, a look at the members of those panels - both to highlight their credentials and how they've distinguished themselves - and to humanise them. And to show that these are people who have no personal axe to grind, are above any kind of group think and who will not be swayed by anything but the evidence at hand.
Whilst that might be another way to persuade the public of climate science's bona fides, I think the most important audience has to be those who hold positions of public trust - our elected and appointed representatives. ie the ones who have been recipients of government commissioned scientific reports and advice but have been choosing to dismiss and ignore:-Whilst the public has some right to their own opinions, those representative do not. Even if it's populism without responsibility that puts them there, once they are, they do have a greater and wider responsibility - to the entire community, not just those who backed their election. For them to endanger our future by wilfully ignoring government commissioned expert advice is a betrayal of that wider trust and responsibility.
Too many of our office holders have been lending climate science denial an air of respectability it has not earned and for those interests who want to obstruct strong climate policy, that high level support from skilled and persuasive speakers in positions of influence is (IMO) a more powerful influence over the scope and the tone of the public debate; 97% won't persuade the public if that 97% can't persuade a clear majority of those who hold positions of trust and responsibility on the public's behalf. -
gws at 07:19 AM on 26 May 2013To frack or not to frack?
some answers and analyses appeared on Climate Central here.
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Dikran Marsupial at 03:53 AM on 26 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Prof. Tung wrote:
The observation now appears to be below the 95% variability bar of the CMIP3 model projections made in 2000
I have already presented an analysis showing that this statement is simply incorrect.
Do you stand by this statement, yes or no? If yes, please explain the error in the analysis.
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Dikran Marsupial at 03:42 AM on 26 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
Prof. Tung wrote:
"However, the technical arguments concerning MLR are probably beside the point."
No, the validity of MLR is providing evidence for your argument is central to the point.
"As I said in an earlier post, the technical analysis related to MLR should not stand on its own: ... "
As I pointed out, the MLR analysis is the central topic of the JAS paper, so it is important to investigate whether it is valid or not.
"... it merely tests the consequence of an assumption of one variable on another. "
My thought experiment demonstrates that the MLR method is unable to perform this test for the reasons stated in my earlier post.
"The technical problem is that the AMO that you defined is 40% of one regressor and 60% of another regressor, and so you ran into a serious problem of collinearity. I think your point could be made without this distraction."
It is not a distraction. The colinearity is the extreme case of correlation between anthropogenic and AMO signals. It is common in thought experiments to investigate the boundary cases. For the MLR method to be a valid test it must work whether or not the AMO actually affects global mean surface temperatures or not, and it needs to be valid whether the AMO is heavily correlated with anthropogenic forcings or not. My analysis shows that it isn't valid as it misattributes anthropogenic influences to the AMO, which undermines the conclusion drawn in the JAS paper.
In my previous post I asked:
"It is very important that you provide me with a direct answer to this question, so we can focuss in on the area of disagreement quickly: Ignoring for the moment whether the hypothetical scenario is appropriate, is there an error in my implementation of the MLR method? "Yes" or "No", if "Yes", please explain."
It is rather dissapointing that you did not give a direct answer to this simple question and instead commented only on the scenario. Please can you answer this question in order to avoid further miscommunication?
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KK Tung at 03:19 AM on 26 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
In reply to post 113 by Dikran: The MLR analysis was used in our paper to investigate the impact on the deduced anthropogenic trend of a mostly natural AMO, with the latter being related to the classically defined AMO index by Enfield. As I said in an earlier post, the technical analysis related to MLR should not stand on its own: it merely tests the consequence of an assumption of one variable on another. Even in Zhou and Tung (2013, JAS), which is a more technical paper dealing with a comparison of the MLR analysis by three groups, there was a whole section, section 4, justifying introducing the AMO index as a regressor. (And the part of the Abstract that you quoted is out of context.)
Nevertheless I still think your exercise is useful in helping to think through the consequences of different scenarios. You should probably come up with a better example because the one you used has a technical problem which may mar the point you were trying to make. The point you were trying to make is apparently important to this group of readers and so I would encourage that you fix that technical problem. The technical problem is that the AMO that you defined is 40% of one regressor and 60% of another regressor, and so you ran into a serious problem of collinearity. I think your point could be made without this distraction.
There are several scenarios/assumptions that one could come up with. These, when fully developed, can each stand on its own as a competing theory. I had in many occasions mentioned that there are competing theories to ours and referenced the ones that appeared in the literature that I knew of. I accepted these as valid competing theories explaining the same phenomenon of the observed climate variability. One fully developed competing theory is that of Booth et al arguing that the entire AMO-like variability is forced by anthropogenic aerosols varying in like fashion. One could also come up with one that says that 50% of this observed variability is forced by anthropogenic aerosol. A third one that says only 20% is caused by anthropogenic aerosol forcing. The first two scenarios could probably be checked by the subsurface ocean data of Zhang et al (2013). The available observational data with their short subsurface measurements and uncertainty are probably not able to discriminate the third scenario from the one that assumes that the AMO is natural.
We can in our thought experiment move closer to the ones that you may be thinking. Consider the scenario where the two cycles in the AMO index, classically defined, in the global mean data is natural but the most recent half cycle starting in 1980 is anthropogenically forced. Therefore the accelerated warming in the latter part of the 20th century is entirely anthropogenically forced. This is a fully developed competing theory, in fact the standard theory. It is fully developed because it has been simulated by almost all CMIP3 models (compare AR4 figure 9.5 a and b). There is no need for internal variability to explain the accelerated warming between 1980 and 2005; the accelerated warming is attributed to accelerated net radiative forcing driven by the exponentially (or super-exponentially) increasing greenhouse gas concentrations in the atmosphere. If we assume that this scenario is true, it would contradict our assumption that the AMO is mostly natural . If you perform a MLR and remove the AMO as natural, the deduced anthropogenic trend would be wrong. In this case it would be an underestimate of the true anthropogenic trend. Putting it in your language of linear vs nonlinear detrending, this scenario is equivalent to the assumption that the anthropogenic warming trend is highly nonlinear and bends rapidly up after 1980. And the wrong (by definition) assumption of a natural AMO can also be viewed as the procedure of linear detrending being wrong. I have said it previously you do not need a Matlab code to reach that conclusion. It is obvious.
Most would have been satisfied with the standard theory, except for what happened during the last decade or so. Although the year 2012 was the warmest on record for the contiguous US, according to NOAA’s National Climate Data Center, it was only the 9th or 10th warmest globally, depending on which dataset is used. The warmest global mean year was either 1998 (according to HadCRU) or 2005 (according to GISS). The year 2010 effectively tied with 2005. The warming in 1998 was rather spikey, and could be attributed to a “super” El Niño in 1997/1998, while the peak near 2005 was broader, indicating a top in the multidecadal variability sometime between 2005 and 2010. Under reasonable emission scenarios the projected warming by the IPCC models continues to rise rapidly after 2005. The observation now appears to be below the 95% variability bar of the CMIP3 model projections made in 2000 and on the lower edge of the 90% bar of CMIP5 projections made in 2005. Explaining this hiatus is one of the current challenges. Some of us proposed that it would be explained by a multidecadal variability, while I readily accepted the fact that there are other competing explanations.
If you have a competing theory, I would encourage you to develop it further. The example you used, with a quadratic trend in anthropogenic warming, does not appear to be consistent with observation, although I understand that you did not intend it to be used that way. The point I am trying to make is that one can come up with a dozen scenarios. When each is developed enough for publication it is open for critical examination by all. However, the technical arguments concerning MLR are probably beside the point.
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DSL at 23:44 PM on 25 May 2013Help close the consensus gap using social media
user6244,
1. Why is it important? The problem can be mitigated by personal and public action.
2. Scientists won't do anything other than their research that points out the problem and their own carbon choices. Engineers will do something, if the political will demands that they do so.
3. Not liking one possible method of making people more responsible is not a good reason to discard the science that's pointing out the problem.
4. Humans not causing the increase? Possible, but not probable. There are threads on this site that are more appropriate, but the short version is this: our emissions are a fact, not an opinion. No matter what mechanism you come up with for the increase in atmospheric CO2, it must account for human emissions and no observed increase in volcanic activity. At any rate, such conjecture is not a good reason for inaction. The cancer analogy is useful: you have $300k in your bank account. Life is sweet right now. You get a terminal cancer diagnosis. You get a total of ten opinions. Nine say terminal cancer. One says indigestion. You say: "well, it could be indigestion. If I accept the cancer diagnosis, then my whole life will be screwed up. I'll want to enjoy the six months I have left, so I'll quit my job and drain my bank account. I think it's indigestion." Wise? By the time the cancer becomes obvious, it will be too late to enjoy the remining time. Not a perfect analogy, of course, because AGW is not terminal. It's like what happens to someone who kicks Moose Molloy in the groin. Moose might accidentally kill the person, but most likely he'll slap the person upside the head for about three weeks.
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user6244 at 23:06 PM on 25 May 2013Help close the consensus gap using social media
Why is it important to convince people of scientific consensus?
Also just what do scientist intend to do to reverse the earths thremostat? Convince world governments to implement taxation so the brunt of the co2 reduction is aimed at the population that can least afford it? Or preventing less advanced countries from increased living standards? Mybe go to war with countries that refuse to limit co2 output?
suppose for a moment that the earth is warming at an alarming rate but turns out that it is not humans causing the increase or we are not the primary driver.
Will we just throw up our hands and walk away?
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MA Rodger at 20:20 PM on 25 May 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
I continue my game of cosmological Where's Wally by crossing the Atlantic. The US Eastern seaboard stretches 1,500 miles so can provide a regional temperature by averaging a set of State data from NCDC, Maine, Massachusetts, Maryland, N Carolina & Florida being chosen. They have a very similar temperature record as shown in the tiny inset graphic. (The anomaly base 1895-1945 is probably the reason for the particularly close match during those years.)
The contiguious ocean SST from nomad3 were taken as 25-45N, 70-80W. (This isn't the most representitive part of the Atlantic SST-wise, lacking signs of warming 1981-date.) AMO is after Enfield.
The first graph shows the land & adjacent ocean temperatures 1981-date do have certain similarities but with warming only evident on land. Also, if the larger wobbles match up, they appear a month or so earlier on land, which is not good for any theory of AMO as a driver of land temperature.
The second graph attempts to compare those US temperature records with AMO over a 120 year period. I see there no evidence of AMO warming the Eastern coast of the USA over that period.
So where is Amo hiding?
Moderator Response:[DB] Added links to the images themselves, as they will not display directly due to limitations in how Google stores them.
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gpwayne at 16:30 PM on 25 May 2013On the value of consensus in climate communication
I'm wryly amused by this little spat, because all the protagonists seem to be operating in the famously closed world of academia - a gentle accusation that is characterised by the comment that the study "doesn’t meaningfully enlarge knowledge of the state of scientific opinion on climate change". My rebuttal to that point is that for those who do climate science, or study it from a lay perspective (e.g. me), scientific opinion is irrelevant to the actual science. There are no planks to my own arguments with contrarians that depend on opinion (wheras nearly all contrarian arguments are not only opinionated, but usually stated as fact).
My arguments depend in their entirity on published papers, the experiments designed to test them, and the evidence that supports them (plus the consilience of climate science with other disciplines, and with the foundational science on which it rests, and with which it must conform).
Yet this study is really important in my view, and to support that view I need to ask that we step out of the scientific community, and into the wider world. On arrival, we might find something disconcerting: while it would be nice to think that the issues we're discussing are about science, in fact the issue is something else entirely, something grubby and distasteful, something that I have found scientists and activists are very reluctant to engage with, and that is propaganda.
We are at war. We didn't want it, but it was forced on us, by those who cannot or will not embrace the implications of the science, and by those whose interests are threatened by those implications i.e. fossil fuel companies. Since the demagogues have no science to back up their arguments, it is necessary to find other weapons with which to wage war, and these weapons are stamped out of molds all too familiar: attacks on credibility and probity, insinuation, misrepresentation, demonisation, conspiracy, and implied or asserted furthering of vested interest. These are the weapons of the ideologue, and what this study does is put an equivalent weapon in my hand - one I have no hesitation in pointing at the enemy, because I recognise that there is good propaganda as well as bad, and what little I contribute is, I hope, of the former kind. It certainly isn't science.
It is also important to understand where this battle is being fought. It is taking place in the media; the paper itself demonstrates that it isn't taking place within the climate science community. And it isn't scientists waging this war - at best, I think scientists feel co-opted, as if they've been caught up in a bar brawl when they were just trying to get a glass of water. Reading Kahan's remarks, there is a sense of frustration and annoyance which he acknowledges, but frames in terms of some putative failure on his part, or on the part of those trying to improve the communication of science. This misses the boat: science will never, ever, convince the public to support political and economic measures to mitigate or adapt to climate change. They don't get it, don't get the compelling probabilities, don't get the causal chain, don't get the timescales or the rapid development, which often appears contradictory or equivocal.
What the public do get is propaganda. They may not recognise it as such, but so powerful is the effect of the constant repetition that the public discourse is blighted and twisted out of shape, where black really can be made to appear white, where there is no nuance and no shades of grey, and where there is no such thing as a fact. And in this petty war, one of the facts most open to attack is the consensual nature of climate science, for the 'unsettled' science is, as John points out, not only Luntz's weapon, but that of the tobacco industry before it, and perhaps more emotively, the principle tool of the National Socialists in the 1930s. I won't repeat Goebbel's aphorism about propaganda, but I will point out the consistency between his application of it, and that of all ideologues who followed, of which Luntz is just one more professional liar.
This is a very old debate: when does the means justify the ends? Previously, I've identified the problem as the 'Bomber Harris' paradox. Harris ran the RAF's Bomber Command and is held responsible for either shortening the war by firebombing German cities, or for destroying the moral credibility of the Allied forces by being as inhuman and evil as the Nazis. This debate carries echoes of the same issue: the denial brigade lie all the time, so we find it incumbent to be truthful. Deniers never admit mistakes, so we have to (as SkS did, bravely, this week - and of course got pilloried for it - was this honesty successful if success is measured in propaganda terms?).
So there's the paradox: while science continues on its quiet course through the long days of number crunching and patient gathering of information, there is a dirty war raging outside. Scientists don't want to be like Harris, don't want to tool up and start burning stuff, and good job too. Leave the dirty work to the soldiers, but don't think this war will be won by science, by evidence, or by banging on about the consensus, for this paper is nothing more than our missile shield, our Patriots, our counter-intelligence. It's purpose is to sabotage the enemy's propaganda, and for that I'm thankful because I'm very short of effective weapons when science and evidence don't work.
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DSL at 13:49 PM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
William Haas, scientific consensus of the sort that Cook has done is not evidence for the theory of anthropogenic global warming. Rather it is an index of the scientific support that the theory has. That index is used by people who don't have the time, energy, training, means, and/or motivation to engage the published science effectively. That would be most people. Like it or not, most people rely on opinion-makers for their opinions. They're forced to.
Question for you, William: do you understand my point?
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DSL at 13:45 PM on 25 May 2013On the value of consensus in climate communication
jdixon, I rarely post intentionally on my wall. Occasionally, I'll be on a thread somewhere and it will show up on my wall. I want to be very careful with the friends and family I've allowed on my FB. The best opportunities are when a friend of a friend makes an unscientific comment and I see it on the home stream. I feel no resistance to correcting the person, and it keeps the friend in observer mode. If the friend wants to discuss it, no problem. I look for situations where I can start conversations. It's very difficult, though, to keep the baseball bat that is the published science in my back pocket. However, I sober up when I think about how insulated my friends are. Most have not had a liberal education that has allowed them to stand back from it all for several years. For most of my friends, I can read their opinions in the content of CNN and FOX. That's not an insult; it's a reality. FB is a liberalizing force, though. The more contact we have with each other's brains and cultural situations, the better. It is easy to de-friend, though, and that's why I walk softly, most of the time.
The family is another matter. My family (up-tree) is small and dying. My in-laws are large and growing. And stereotypically Southern (US) for the most part. Some will say one thing in conversation and then whisper something else behind the back. It's very annoying to someone who likes and encourages transparency of thought. I've had my sit-downs on climate with a few of them, the mother-in-law in particular. Again, though, anger is of no use. It often takes years for evidence to begin to change belief. Fortunately, my sister-in-law is heavy into sustainable living and community development. They think she's flaky, but she's cute and funny so they tolerate her "wierd side." We do occasionally do FB team-ups with family members when they get too obnoxious.
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Glenn Tamblyn at 10:11 AM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
William Haas
All science requires consensus. The oft used claim is that it is about evidence not consensus, which is actually a very confused statement.
Of course it is about the evidence for something. Does the evidence support the hypothesis or not? To determine this one has to evaluate the evidence and form a conclusion, an opinion, about whether the evidence supports the hypothesis or not. And each individual forms their own opinion on this. You and I might look at the same evidence and form different opinions about whether that evidence supports the hypothesis. So whose opinion should we accept, yours or mine?All knowledge is a consensus of the opinions of many people about the significance of evidence. If a large number of people share the same opinion that the evidence supports the hypothesis, we tend to accept that it does.
Was the proof of Fermat's Last Theorem a few years back a valid proof? Yes, because that was the consensus of the many mathematicians who evaluated the proof.
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Tom Dayton at 09:42 AM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
William Haas, you should read the post "Is There a Scientific Consensus on Global Warming?" to understand what is meant by "consensus." To make your example from mathematics applicable, you must address mathematicians' consensus on whether that single counterexample really does invalidate a theorem. If you believe that all mathematical counterexamples are correct, you are living in a fantasy world.
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William Haas at 09:36 AM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
The case for AGW must be really shaky if a "scientific consensus" is required to substantiate it. "Scientific consensus" is really an oxymoron because true science does not require a consensus. The idea of voting on scientific truths seems totally alien to me. It is just like the political entity that voted to change the value of pi. In mathematics it takes only one counterexample to invalidate a theorem.
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John Russell at 09:20 AM on 25 May 2013On the value of consensus in climate communication
One only needs to see how often the consensus is brought up as an arguing point by those in denial to know that this new paper has great value when it comes to the politics of climate change.
But clearly it's neither here or there when it comes to the work of climate scientists trying to pin down the likely outcomes of steadily raising the planet's atmopheric CO2.
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Dikran Marsupial at 08:33 AM on 25 May 2013It's cosmic rays
JRT256: Firstly sun-spot numbers are correlated with total solar irradiance (TSI) as well as cosmic rays. So a correllation between sunspot numbers and climate does not necessarily involve cosmic rays as the causal mechanism.
Secondly, a link was provided to the "body of scientific research has determined that GCRs are actually not very effective at seeding clouds." (i.e. the advanced version of the article). The cosmic ray theory is not unlikely to be correct because it doesn't explain all warming, but because of the scientific research that has been performed has identified several problems with the causal mechanism, If you want to discuss the details of any of the papers mentioned, I'm sure there will be plenty of contributors willing to discuss them with you.
"it is more reasonable from a scientific point of view to try to figure out why the correlation broke than to use this fact to try to prove that the hypothesis is false."
Actually, the most plausible theory is that there is more than one forcing that affects climate; changes in total solar irradiance and the rise in greenhouse gasses explains the breakdown in the correlation pretty well. However, proving hypotheses to be incorrect is a fundamental part of scientific method. Ruling out hypotheses is a good a way of finding out why the correllation broke down as any.
Lastly, as a word of advice, if you want to have a discussion of science, starting by using phrases such as "That is both unscientific and fallacious reasoning." when you yourself obviously have not understand the argument put forward in the article is unlikely to be conducive to constructive dialogue. Note I have taken pains to reply in a rather more civil manner.
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JRT256 at 07:57 AM on 25 May 2013It's cosmic rays
IIUC, you are denying the scientific hypothesis that there is a correlation between sunspot numbers and climate on earth. Your argument appears to be that because this hypothesis doesn't account for all global warming, that it doesn't account for any global warming. That is both unscientific and fallacious reasoning.
We have history that provides strong evidence that this hypothesis is correct. The Maunder Minimum and the Little Ice Age being most significant. Still, it is true that we do not completely understand the action mechiism.
You are correct to point out that this correlation broke in the second half of the 20th century. However, since it has been so strong historically, it is more reasonable from a scientific point of view to try to figure out why the correlation broke than to use this fact to try to prove that the hypothesis is false.
Might I suggest one possible cause which is CFCs. It is now belived that CFCs had a stronger effect on global warming than was once thought and their concentration in the atmosphere, taken as a factor (possibly with a delay in time) allong with the sunspot number as a proxy for solar activity in factor analysis might yield a reasonable answer to the question. -
DSL at 07:15 AM on 25 May 2013It hasn't warmed since 1998
Chemasan, the methodology of Levitus et al. (2012) includes Argo data. Go here to see the results. If you choose Jan-Mar on any of the 3-month sets, you'll get up to 2013. I strongly suggest using the 0-2000m set. Here's global 0-2000m for all months:
2005-3 8.972987
2005-6 9.391529
2005-9 9.681848
2005-12 12.636982
2006-3 11.932278
2006-6 12.998004
2006-9 12.264493
2006-12 13.356965
2007-3 13.49815
2007-6 11.382808
2007-9 12.277043
2007-12 12.418795
2008-3 13.305184
2008-6 14.606297
2008-9 13.024848
2008-12 12.090649
2009-3 12.614719
2009-6 12.241169
2009-9 13.816815
2009-12 15.052814
2010-3 15.881298
2010-6 13.484779
2010-9 13.959781
2010-12 14.823184
2011-3 15.215552
2011-6 14.630487
2011-9 16.870249
2011-12 14.859973
2012-3 17.308126
2012-6 15.461417
2012-9 15.34632
2012-12 16.630146
2013-3 19.332438The annual running average produces a linear trend of +1.74*10^21 joules added per year.
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Chemasan at 06:50 AM on 25 May 2013It hasn't warmed since 1998
For #40 and #50. Have you check Argo Project? It seems NO. Argo project the most serious study of the T and sea levels didn't observe increase in the T. It's true that it a new project (since 2005) but data is more accuracy.
Moderator Response:(Rob P) You can use the search function to find a response to most climate-related questions. For example on the observed warming of the oceans:
1. Ocean Cooling Corrected, Again
2. Levitus et al. Find Global Warming Continues to Heat the Oceans
3. Nuccitelli et al. (2012) Show that Global Warming Continues
4. Observed Warming of the Ocean and Atmosphere is Incompatible with Natural Variation
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R. Gates at 06:08 AM on 25 May 2013A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
William,
That rising air and positive AO mght indeed happen (especially in the warmer months), in which case we might get more storms like the Great Arctic Cyclone of 2012 (early August 2012, to be exact). These storms not only bring up warmer water from depth, but also draw in more energy to the Arctic via the atmosphere as the strong low pressure pulls in wamer air from lower latitudes.
But there is another huge dynamic that I mentioned in my post #12 that must not be forgotten-- and that's the effects of SSW's on the AO. These events, happening mainly from late November through February, begin high above the Arctic, and with the warm descending air, turn the AO very negative, and push the colder air out of the Arctic and we ususally see warmer than normal temps in the Arctic proper. Most importantly, the causes of these events begins at lower latitudes, and are related to large-scale planetary waves whereby we can see the same SSW event having simultaneous (though opposite) effects over the pole and over the equator, 9000km away.
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Rob Honeycutt at 04:54 AM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Thanks Tom. I'm actually less stuck on the specific 97.1% figure that it may seem. The fact that all this research, taken collectively, and taking the fact that Cook13 is such a large sampling of research, should tell people how robust the conclusions actually are.
Again, I would challege any other group to perform a similar research project, using their own wording, and see if they can come up with appreciably different results. The point being, Barry, Lucia, Schollenberg and others can quibble until the cows come home, but until they do their own research (and get it published) they have little ground to stand on.
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Tom Curtis at 02:55 AM on 25 May 2013Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Very briefly, all participants in this debate would do well to read Bray and Von Storch 2010 (particularly question 21, which shows that in 2008, 83.51% of climate scientists where significantly convinced that "most of recent or near future climate change is, or will be, a result of anthropogenic causes"). Note that this is not inconsistent with Cook et al 2013 because (a), climate scientists "convinced by the evidence" publish approximately twice as many papers on climate science on average relative to those unconvinced by the evidence (Anderegg et al, 2010), and (b), those not significantly convinced may well not be convinced for reasons other than the weight of evidence, and hence lag in proportion the balance of evidence as seen in the literature. It should place a constraint on the over interpretations and the absurd underinterpretations of Cook et al 2013.
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