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Comments 36801 to 36850:

36801. Composer99 at 22:44 PM on 8 May 2014
       There is no consensus
       

       Climate change is happening, I don't know anyone who disagrees so stating that as part of an argument tends to lend itself to the logical fallacy of false implication.

       There's a TV program discussing the failure of climate-related legislation to work its way through the US Congress in 2010-2011. Sadly I do not recall the name, although I believe it is featured here on Skeptical Science.

       One of the spots in the program showed Christopher Monckton egging on a Tea Party rally in, if memory serves, 2010 during the run-up to the Congressional elections.

       On at least one occasion, Monckton gets the crowd to chant that global warming/climate change is a hoax. (This ties in to the recent "quantum nature of climate science denial" that John Cook posted about, as Monckton is also on video record saying that global warming is caused by the Sun.)

       If you really don't know anyone (or know of anyone) who has denied that global warming/climate change is really happening, you aren't reading enough Internet comment threads IMO.

       I'm skeptical of both sides particularly because so many of the key players have a profit motive.

       Go to your closest university with atmospheric physics department and look at the cars the scientists drive.

       My interest here is to find out the truth based upon as much hard science as possible and not be side tracked by spin, emotionally driven or financially motivated agenda's.

       Okay then, go read the IPCC AR5, or maybe the US National Climate Assessment.

36802. Dikran Marsupial at 21:18 PM on 8 May 2014
       There is no consensus
       

       bakertrg Your car based analogy is misleading because there are many causes of premature death, but there are only two possible causes of climate change, namely anthropogenic or natural (or a combination of both).  If a paper takes the position that climate change is predominantly anthropogenic, that is implictly taking the position that is is (at least mostly) not a natural phenomenon.

       97% of the papers that take a position on the question do take the position that it is mostly anthropogenic.  The papers that do not take a position on the question (and the vast majority of papers on climate change do not) shed no light on the question and hence are not included.

       If you want a study of scientists that are publicly stating that humans are the primary cause of climate change, then you won't find one, because scientists have better things to do, however as a start, you could just list the names of the authors of the IPCC WG1 reports (there are a lot of them).  Then you can add the authors of the statements made by the scientific bodies that Daniel Bailey mentions. 

       As to your last paragraph, if you think that correlation is the only reason we have to think that CO2 causes climate change, you are mistaken (or at least your information is out of date by at least 70 years, the phsyical mechanism of the greenhouse effect was worked out in detail by Calendar and Plass in the 1950s and 60s).  If you think that the greenhouse effect does not exist, then I suggest you read Roy Spencers list of skeptic arguments that don't hold water (in particular item #1).

36803. CBDunkerson at 21:16 PM on 8 May 2014
       It's cooling
       

       jetfuel wrote: "This has to poke a hole in the "Polar Vortex" story"

       Umm... why exactly? Even if we pretended that Arctic sea ice really was 'recovering'... how would that call in to question the long term common Arctic air flow pattern?

36804. chriskoz at 20:27 PM on 8 May 2014
       2014 SkS Weekly News Roundup #19A
       

       Interesting new study that sheds light on the famous "hidden decline":

       Arctic tree rings as recorders of variations in light availability (also press release)

       In a nutshell: "the decline" is the lowered sensitivity of tree rings due to decreased amount of light - the result of sharply risen aerosol pollution after 1950s. A hypothesis put forward at least a decade ago by Keith Briffa, but quantified for the first time in this study. Worth reading as an evidence to hopefully put to bed the "Mike's Nature trick to hide the decline" meme. Well at least in the minds of those who think critically.  Unfortunately those who keep parroting said meme, largely do not think at all, so they are resistant to any form of rational argumentation.

       Moderator Response:

       (Rob P) - Yes, I've just noticed that paper too. Interested in writing up a post about it?

36805. bakertrg at 20:18 PM on 8 May 2014
       There is no consensus
       

       OK so my original comment got deleted so I'll just go one fact at a time and see how things go. First I'm not a climate change denier, I'm skeptical of both sides particularly because so many of the key players have a profit motive. My interest here is to find out the truth based upon as much hard science as possible and not be side tracked by spin, emotionally driven or financially motivated agenda's.

       First, I question the message of the big red logo declaring "97% of climate papers agree that global warming is happening and we are the cause". Climate change is happening, I don't know anyone who disagrees so stating that as part of an argument tends to lend itself to the logical fallacy of false implication.

       The logo clearly implies that we are either the only cause or the major cause of global warming but that is definitively not what 97% of climatologist or climate papers state. The implication of the conclusion does not match the data and the fact no one on this site is addressing that fact makes the conclusion seem greatly biased.

       To give an example of my point, I think if you had a bunch of peer reviewed science on premature causes of death in adult males in the united states you would get 100% consensus that car crashes cause deaths. If you then made a logo that stated 100% of scientific papers agree that car crashes are THE cause of premature death in adult males in the united states would that be an accurate way to use the data?

       Is there a report/study of the number of climate papers or climatologists who are publicly stating that humans are the primary or sole cause of the climate change? I have done a lot of reading on this site but have not found that study. Additionally the fact it's being repeated adnauseum makes it seem like there's a conscious effort to eliminate skepticism through the use of that logical fallacy (ad nauseum) as well.

       Though I agree CO2 emissions do appear to have a potential causation in some of our climate change (the only fact here is correlation and real scientists know that causation and correlation are not the same) but there is lots of data that is contrary to this assertion. From 1900 until 1940 temperature was dropping despite the unmitigated rise in CO2 levels. That doesn't make a lot of sense if AGW is the major cause of global warming.

36806. michael sweet at 20:12 PM on 8 May 2014
       It's cooling
       

       Yesterday PIOMAS came out with Arctic Sea Ice Volume measurements (h/t Neven).  Their site says:

       "The 2014 ice volume reached its annual maximum in April with 22,900 km3 which is just slightly below the long term trend and is the second lowest on record; just 400 km3 above the previous April minimum which occurred in 2011. However, variations over the last 4-years are well within the error bars of the volume estimates so that inter-annual variability over this period maybe due to errors in the sea ice reanalysis."

       This is the second lowest annual maximum on record.  Within the error measurements it is equal to the record low.  Where did Jetfuel come up with a recovery???

       Another set up for an interesting summer in the Arctic.

36807. Dikran Marsupial at 19:56 PM on 8 May 2014
       It's cooling
       

       Just to add to Tom's comment on the three recovery winters, thisimage from the NSIDC puts those winters into context very nicely:

       

       The annual maximum sea ice extent usually takes place in March each year, and as you can see the last three winters have basically followed the long term declining trend in March sea ice.

       My recommendation to jetfuel is to look at the long term trends because measurements for individual years or a few years are too susceptible to cherry picking.  As Tom says, the winter sea ice extent maximum is not a good predictor of the summer minimum, as it depends a lot on Arctic weather during the summer (which causes a lot of variability around the long term trend).  Also we should expect a larger *increase* in sea ice following a decreasing summer minima, simply because it leaves more open water to freeze (which gives a good opportunity for a misleading report of the "recovery", indeed SkS rebutted such arguments made by WUWT and Steve Goddard last year).

36808. Tom Curtis at 17:04 PM on 8 May 2014
       It's cooling
       

       Jetfuel @213 writes, "There have been 3 consecutive recovery winters at the Arctic."  Those would have to be the winters of (in reverse order) 2013/14, 2012/13, and 2011/12.  It is amazing how the summer record low Arctic sea ice extent in 2012, with a minimum sea ice extent nearly half (55%) of the 1981-2010 mean, and around 1/5th lower than the prior record in 2007 (82%).  That the winter of 2011/12 could be a "recovery winter" clearly shows that what ever that undefined term means, it is irrelevant to Arctic sea ice analysis.

       Even worse, the Arctic sea ice extent as of May 5th was 13.07 million km^2, only 0.657 million km^2 (4.8%) less than the 1982-2010 record, but still the third lowest on record - and lower than any year since 2007.  So not only are "recovery winters" no indication of summer sea ice extent, they are no indication of spring sea ice extent either.

       

       Jet Fuel, in other words, is feeding us irrelevant (and dated) data, not to mention completely failing to indicate how the facts he adduces are relevant to either the OP, or the claims he makes about polar vortexes. 

36809. Dave123 at 14:23 PM on 8 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       So now we wait to see where "warren" surfaces to claim he was censored.  Such a tedious business.  I have a feeling...can't explain it, that "Warren"  was a troll with muliple sock puppets recently banned from SLATE. 

36810. John Hartz at 13:20 PM on 8 May 2014
       Is a Powerful El Niño Brewing in the Pacific Ocean?
       

       Also see the World Meterological Association (WMO) press release of April 14:

       WMO Update Indicates Possible onset of El Nino Around Middle of Year

36811. jetfuel at 10:44 AM on 8 May 2014
       It's cooling
       

       Global cooling - Is global warming still happening?

       My first post: Antarctic ice is above 1981-2010 mean. March 20, 2014 Arctic ice is 3-5% below that same mean. There have been 3 consecutive recovery winters at the Arctic.Arctic sea ice area is 800,000 sq. km. below mean amount of >15% sea ice coverage. This is a lot, but this past winter added 800 cubic miles (3200 GTonnes) to the Arctic ice mass, to reach a peak of 2200 cubic miles of sea ice. This has to poke a hole in the "Polar Vortex" story. With normal ice volume, near normal ice area, how could it be so warm that the polar vortex was caused. This polar vortex narrative is getting harder to justify as each day goes by.

       Moderator Response:

       [JH] Pelease cite the sources for your data and for your assertions.

       BTW, your subesequent comment was pure unadulterated, off-topic, concern trolling. It therefore was deleted. 

36812. Tom Curtis at 09:16 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       skeptical101 @12:

       1)  Fyfe et al show the difference between model predictions and observations, but then note that there are several distorting factors in that comparison.  The try to characterize those factors, and adjust the results accordingly, with the results shown as the residuals in figure 3:

       

       As can be clearly seen, the adjusted temperature data lies clearly within the 95% confidence interval of the adjusted model data.  Hence, based on Fyfe et al, the models have not been falsified.  Suggestions to the contrary merely misrepresent their paper.

       As a side note, it is worthwhile noting that the only adjustment required for the model data is the volcanic adjustment, which brings the CMIP5 results inline with the CMIP3 results.  That shows the difference between them is largely a function of the relative date of the data runs to historical volcanic erruptions.  "Skeptical" claims that that discrepancy can only arise from a difference in climate sensitivity are shown, therefore, to be far from skeptical, and to merely read into data the conclusions they wish to find rather than analyze the data on its merits.

       2)  The adjustment algorithm uses in Fyfe et al was one developed by the CRU team, and so is a reasonable choice of algorithm.  However, it is not the only algorithm used for that purpose, and differs substantially in its resulst from other algorithms.  This may be, in part, due to its use of successive singular regressions instead of a multiple regression, with the former method being fraught with perils.  Fyfe et al also use a method which determines a "forcing" from ENSO from the tropical east Pacific rather than from temperatures.  This indirect method may introduce further errors.  The end effect is that the adjusted observed trend from Fyfe et al are significantly less than the approx 0.17 C per decade obtained by multiple regression by Foster and Rahmstorf, or the 0.16 C per decade from the intuitive method by Nielsen-Gammon:

       

       3) One way to address which regression gives the most accurate result would be to compare their adjusted trends across all trend intervals to see if they come out the same.  If they varied widely the adjustment is not reliable.  Unfortunately Fife et al saw fit to only compare across to trend intervals.  However, comparing the mean of all trend intervals in a given period should largely average out short term factors such as ENSO and volcanic adjustments.  The result will be a fair estimate of the underlying trend.  When we do so with CMIP5 and with the three main temperature records we fins an underlying trend for CMIP5 matching that for Fyfe et al, and for CMIP4, and a discrepancy between observations and models far closer to that obtained by Foster and Rahmstorf than that obtained by Fyfe et al.  That give greater confidence in the former than the later:

       

       4)  All of these methods still leave a small discrepancy between models and observations, most likely in the range of 15-20%.  It is probable, however, that at least part of that discrepancy is due to an under reporting of observed trends as shown by Cowtan and Wray, and by the recent Best global (land plus ocean) tempertature record.  In all, it is likely that models slightly over estimate the underlying trend, but the over estimate is far less than that indicated by Fyfe et al.

36813. Skeptical101 at 08:55 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       I'm not a statistician so I definitely missed the finer point. From an everyday laymen perspective, where this battle is being waged, evidence, for better or worse, is debated based on the end result.
       
       The models , regardless of what it is they are doing or attempting to account for (be it "variability" or "climate sensitivity"), in the end make a projection. That end number, that projection, from what is being presented to me clearly "seems to be" at odds with observational data.

       (Rob P) See this SKS post: Climate Models Show Remarkable Agreement with Recent Surface Warming for a discussion of the CMIP5 climate model projections. And contrary to your claim, note the agreement between observed warming and the models when the models are fed the climate forcing that actually occurred:

       
       
       If that end projection is in fact anywhere near that far off from observational data, we should not use it as an argument to support AGW.

       That is not to say that scientist should not continue to work on them. I recently listened to a debate between Kerry Emanuel and John Christy. When John brought up the model discreptancy issue, Kerry essentially said "the models suck right now, I don't like them but we still have all this other evidence that in context says we are definitely under AGW and it is serious." [my words not Kerrys]
       
       Now, if Kerry is conceiding that point, one which is being made by other respectable scientists (as seen in this paper), that should clearly make one think about bringing up the models as evidence for AGW. From the previous comments on this thread, one would think the assertions by Christy are insane. 20 years is not an insignificant number! According to Kerry, the models also undershoot temperature before that time.

36814. KR at 08:24 AM on 8 May 2014
       Models are unreliable
       

       marisman - So, you would prefer a complete ab initio approach from the ground up, extrapolating from basic physics (do your semconductor models go from the level of quarks, since those affect electrical charge and mass at the molecular level?). This rapidly scales to the ridiculous. 

       At each scale level you still need to validate the behavior of that model scale against observations - meaning that when looking at global models you will still be dealing with effectively black box parameterizations at scales below what you can computationally afford. 

       Which is exactly what gets done in any computational fluid dynamics (CFD) or finite element analysis (FEA) - once you get below computational scale you use parameterizations. Techniques that have a proven track record despite sub-element black boxes. 

       Granted, GCMs don't do as well at the regional level, let alone the microscale of local weather. But as pointed out before, they are boundary value models, not initial value models, and energy bounded chaotic behavior from ENSO to detailed cloud formation mean that there will be variability around the boundary conditions. Variability that, while it cannot be exactly predicted in trajectory, is not the output goal of GCMs. Rather, they are intended to explore mean climate under forcing changes (~30 year running behavior).

       Note that coupled GCMs do use sub-models such as atmosphere, ocean, ice, land use, etc., individually validated and exchanging fluxes to form the model as a whole. 

36815. marisman at 07:43 AM on 8 May 2014
       Models are unreliable
       

       Listening to Dr. Gavin Schmidt speak, he spends a fair amount of time talking about how complex the problem is.  I agree.  That is my point entirely.  While I don't study climatology, I do understand what you do.  I also understand computer modeling.  It matters little whether your are modeling semiconductor physics, planetary motion, human intelligence, or the Earth's climate.  Many of the same principles and limitations apply.

       I believe a better solution for the modeling problem is to cease making it an all encompassing model as Dr. Schmidt argues in favor.  He says the problem cannot be broken down to smaller scales  - "it's the whole or its nothing".  I could not disagree more.  The hard work of proper modeling is to exactly break the problem down in to small increments that can be modeled on a small scale, proven to work, and the incorporated into a larger working model.

       Scientists didn't succeed in semiconductor physics by first trying to model artificial intelligence using individual transistors.  They began by modeling one transistor very well and understanding it thoroughly.  Thus, assumptions and simplifications that were of necessity made moving forward through increasing complexity were made with a thorough understanding of the limitations.

       Let me suggest then as an outsider that you exactly do what Dr. Schmidt says can't be done.  Create a model of weather with proper boundary conditions on a small geographical scale. 

       It seems like a good place to start is a 100 km^2 slice.  That would give similar scale up factors (7-8 orders of magnitude) to the largest semiconductor devices today.  Create a basic model for weather patterns of this small square. 

       Hone that model. Make it work. Show that it does. Understand the order of effects so that you then have the opportunity to use any number of mathematical techniques to attach those models with their boundary conditions side by side with increasing complexity and growing area but necessarily greater simplification yet losing little accuracy.

       That is exactly the way that successful complex models have been built in other fields.  I think the current approach tries to short cut the process by trying to jump to the big problem of modeling over decades too soon.  If you have links to those that might be attacking this small scale modeling project, I'd like to have that resource.  It would interest me greatly.

36816. John Hartz at 07:30 AM on 8 May 2014
       CO2 is plant food
       

       Given the information presented in the following article, an update of this rebuttal may be in order.

       Climate change making food crops less nutritious, research finds
       High

       CO2 levels significantly reduces essential nutrients in wheat, rice, maize and soybeans, Nature paper reveals

       Damian Carrington, The Guardian, May 7, 2014 

36817. Rob Honeycutt at 07:11 AM on 8 May 2014
       Models are unreliable
       

       marisman @692...  You're making several common of mistakes regarding climate modeling and climate science.

       First, climate science is not young. It dates back nearly 150 years. It's a well developed field with well in excess of 100,000 published research papers, and 30,000+ active climate researchers today. The fundamental physics is very much settled science. There are uncertainties but those are generally constrained through other areas of research. For instance, we have high uncertainty on cloud responses to changes in surface temperature, but we also have paleodata that shows us how the planet has responded in the past to changes in forcing, thus we can assume the planet will behave at least fairly similarly today.

       Second, it sounds to me like you're making huge overreaching generalizations about climate modeling when you don't even have a basic understanding of how climate modeling is different from your own field. Climate models is a boundary conditions problem rather than an initial conditions problem. Climate modelers do not pretend they are creating a perfect model of how weather will progress over time, leading to climate. Rather, climate models test responses to changes in forcing and project (rather than predict) what might occur run out over many decades. They do not pretend to predict climatic changes from year to year or even within decadal scales.

       Third, you make an error in stating that modelers don't have a scientific understanding of how climate works. The link below is to Dr Gavin Schmidt discussing how models are created. Maybe instead of making such sweeping claims about a field of science where you have little understand, you can take a moment to try to start to understand what climate modelers actually do.

       Dr Gavin Schmidt, TED Talk

36818. marisman at 05:57 AM on 8 May 2014
       Models are unreliable
       

       Just a different scientific perspective on modeling from another arena...

       Semicondcutor device physics is used to model behavior of transistors that is key to driving the whole of small scale electronics that runs today's devices.  These are complicated models that are relied on by designers (like myself) to create working circuits.  If the models are wrong, the some or all of the millions of transistors and other devices on the chips don't work.  This is modeling.  The reason it works is that not only does it predict past behavior and predict future behavior, but the underlying science for why the models are accurate is understood to extreme detail.

       As a scientist, what is missing for me in climate modeling is the actual scientific understanding of how climate works.  Understanding this is a tall order, you would think that some humility would exist in the climate modeling community due to their understandable ignorance about something as complicated as the climate of a planet over long periods.
       (-snip-) Climatology is a relatively young endeavor and a worthwhile one but it has a long way to go to be considered settled and understood.

       Moderator Response:

       [Dikran Marsupial] Inflammatory tone snipped, suggesting that the climate modelling community lacks humility is also sailing close to the wind.  In my experience, climatologists are only too happy to discuss the shortcomings of the models, for example, see the last paragraph of this RealClimate article.  Please read the comments policy and abide by it, as you are new to SkS I have snipped your post, rather than simply deleting it, however moderation is an onerous task, and this will not generally be the case in future.

36819. Dikran Marsupial at 05:56 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       skeptical101 you need to read the supplementary matrial in detail.  I am a statistician, so the point was easier for me to spot than it would be for those with other backgrounds.  Using the spread of the models *is* an established method, but that is pretty much because there are no real alternatives as we can't estimate the plausible variability of the climate from the single realisation that we can actually observe (i.e. the Earth's actual climate).  However, that doesn't mean that it is robust.

       Fyfe et al. is just one paper on this topic, there have been many other groups working to understand the cause of the apparent model-observation difference.  IMHO Fyfe's paper overstates the conclusions.  The best approach is to look at every paper in the context of the other published on the same topic.

       It isn't really possible to take a simple position on the matter without leaving out important caveats.  We fundamentally don't know whether the models are underestimating variability or overestimating climate sensitivity or both.  We will get more confidence on this as the amount of data increases, but the uncertainty won't go away completely.
        

       It is worth noting that the 1998/99 El-Nino event pushed the observations about as high into the upper tail of the model projections as they are into the lower tail now.  Does that mean that the models underestimated climate sensitivity then and overestimate it now? 

       It is also important to note that the models are not designed to project climate on a decadal basis, but on a centennial basis, where the effects of internal variability can more reasonably be expected to average out.  This means that just because the models are struggling to explain recent climate, that does not imply that their centennial projections are unreliable.

       In my opinion, it is a case of "a bit of both". 

36820. davidnewell at 05:31 AM on 8 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Eventually, everyone will become convinced of "the problem".  If there is a "god", it's name  is called "Reality",  and "it" cares not about the machinations, denials, beliefs, ideologies, or opinions of any person whatsoever. 

       "We", who argue about the finer details of "this", and "that", with those whose beliefs are otherwise..  need only "wait a while", to see who is right, and who isn't. 

       Meanwhile "The Times, They are a Changin".  huh: seems damned obvious to me..

       thanks,

       d

36821. Skeptical101 at 05:28 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       "Thus we employ here an established
       technique to estimate the impact of
       ENSO on global mean temperature, and
       to incorporate the effects of dynamically
       induced atmospheric variability and major
       explosive volcanic eruptions5,"

       are you saying this is not as "established" as they claim it is. Are they publishing such a report on Nature Mag claiming such vasts differences on models vs observation which are just  statistical tricks? Is there another method that would make the model right?

       Is it not possible to take simple position on the matter? Something like "The models are correct given blah blah blah"  or "Yes, the models are off by a significant margin for a 20 year span".
       
       Fyfe and company are claiming model predictions are off by roughly 50%!! 0.30 ± 0.02 °C vs 0.14 ± 0.06 °C   ....  This is not a small margin!

36822. MA Rodger at 01:22 AM on 8 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       It was curious that somebody who professed to have been “a strong supporter of alarming warming during the 90's” and who stated they still consider CO2 emissions cuts and renewable energy are “great outcomes,”  would have managed to effect some major upheaval in his understanding of things climatological caused by such a banal reason of somebody claiming it will soon never again snow in London (shock-horror), or some ridiculous claim that seas will rise by 9 metres by 2100.

       That this same person also considered a 6ºC global temperature increase in the same light (which I believe is an upper value projected by IPCC AR5 under BAU), had problems accepting the millennial NH temperature reconstruction of Mann et al 1999 (an presumably every other such reconstruction produced since 1999) while picking out the Daily Mail-esque nonsense-claim of an ice-free Arctic by 2013 as yet another profound gripe – how can this have been a serious student of climatology? Surely such claims were far too puerile to be legitimate.

36823. KR at 01:17 AM on 8 May 2014
       Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz
       

       The same approach as discussed in the OP (carpet-bombing FUD both before and after publication of a significant report) can be seen with the US National Climate Assessment released 5/6/14. Multiple blog posts at WUWT, JoNova, Currys blog, Michaels and Knappenberger over at the CATO institute, Morano at ClimateDepot, swarms of commentaries from FOX News, etc. 

       It appears those in denial feel threatened by significant reports on the science of climate change. At this point I treat any observed frenzy in the denier camps as a recommendation to read what they are so upset about...

36824. Dikran Marsupial at 01:11 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       My main reservation about the Fyfe paper is that the statistical test that it uses estimates the plausible variability due to internal climate variability (things like ENSO) from the spread of the model runs around the mean for that model.  If the models are unable to predict the forced response of the climate (i.e. the climate change caused by changes in forcings such as CO2) then I don't see how they can be expected to accurately model the unforced response (internal climate variability).  IIRC the details of this are in the supplementary material, rather than the paper.  Thus the statistical test is not a particularly reliable one, and the authors have not really taken this into account.  I prefer the more basic test of seeing whether the observations lie within the spread of the model runs, which seems a little more robust.  Essentially either the models over-estimate the warming, or they underestimate the internal variability, or a bit of both.

       The fact that mainstream scientists discuss this is of no surprise to me, I work with climatologists every now and again and they spend lots of time criticising models because making them better is what they do for a living, and you can't improve something without being aware of the deficciencies.  However,  at the same time you need to keep some perspective and look into other reasons for the apparent difference, e.g. by controlling for the effects of ENSO.  The mainstream position on this varies from "its the models" or "its internal variability" and everywhere in between, with I suspect "somewhere in between" being considered the most plausible (at least according to the climatologists I have discussed this paper with).

36825. Skeptical101 at 00:43 AM on 8 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       okay ... so before I get my head chewed off, I want to say that if your only reply to me will be how stupid I am, or how it should be clear to me that the models are right, please address that to someone else.
       
       From what I've gathered several prominent folks point to  the model are significantly off in their projections. This is not just something that sceptics bring up. Folks who support AGW do so as well. Here is short article published on Nature that says the same thing.
       
       LINK
       
       What do you all think? and when I ask this question I mean thoughtful commentary/criticism

       Moderator Response:

       [Dikran Marsupial] Please just ask the question in a calm rational manner, and you will find plenty of people happy to have a rational discussion about the answer, however your defensive tone is unlikely to result in productive discussion.  Rather than just point to an article, ask a specific question about it.  Link to the paper activated.

       [RH] Shorten URL that was breaking page format.

36826. bakertrg at 00:28 AM on 8 May 2014
       There is no consensus
       

       posted a comment, did it get deleted?  if so could someone point out why so I'll be able to better form future comments?

       Moderator Response:

       [Dikran Marsupial] Your posts were indeed deleted, due to sloganeering.  Please see the comments policy and adhere to it.  SkS is a good forum for rational discussion of science, but rhetoric and inflamatory tone tends to be counterproductive, so please dial back the tone.

36827. Dikran Marsupial at 23:19 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Can I suggest that we DNFTT and leave the moderators to deal with Warren's childish attempt to bait Glenn. He has made it abundently clear that he is not here for rational discussion, so he doesn't warrant any further attention.

       Moderator Response:

       [JH] I have deleted a number of Warren' s recent. concern troll, mini-posts. They were indeed childish. We have also asked our lead Moderator, Daniel Baily, to relieve Warren of the privilege  of posting comments on SkS. 

36828. chriskoz at 23:17 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       I need to note that Warren continues to mispell our names, despite he's been warned by a mod@10 where he rather wildly mispelled Dikran's name (it was not a typo IMO). Warren Hindmarsh@38 miselled the name of Composer99 as "composor99" (sic!).

       I also need to note that frequent mispelling of other names is his typicla modus operandi: e.g. he made plenty of mispells in the thread recently cut by mods (so the cuts did him a favour by removing embarassing evidence).

       Based on the above, and on top of the facts that Warren does not make grammar nor ordinary word spelling errors (far fewer than I do for example), I conclude that Warren's mistakes are an indication of his carelessness & lack of respect for people he discusses with. IMO, such lack of respect is another characteristic of deniers and/or ignorants. Those who take the debate seriously, do pay attention to the respect aspect, especially when warned about it.

36829. Dikran Marsupial at 23:04 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       O.K. Warren it is clear that you are just trolling, sorry, I have better things to do than indulge that sort of behaviour any further.  It has not escaped me that you have ignored the substantive points in my post (that you can't simply ignore physics) and have instead focussed on yet more word play. 

36830. Composer99 at 22:55 PM on 7 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       Dr Spencer's "top 10 worst 'skeptic' arguments".

36831. Composer99 at 22:53 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Speaking personally again, I do find the current and projected impacts of global warming alarming. But you don't have to find them alarming or be alarmed to support mitigation via emissions reductions - you only have to conclude, based on the available evidence, that the human and socioeconomic costs and penalties for failing to mitigate warming exceeed the costs and penalties of mitigation. And, as others have noted, you can't exclude the worst case scenarions just because you think they're "alarmist", as long as they have a non-trivial likelihood of occurring.

36832. chriskoz at 22:48 PM on 7 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       Can someone provide a link Spencers 10 worst 'skeptic' arguments, for completeness of the discussion herein? Thanks.

36833. Composer99 at 22:47 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren, you state:

       we know "about 0.75c per century" is not [alarming].

       To paraphrase Dikran, whether some phenomenon is alarming or not is a question of the observer's attitude towards the phenomenon. After all, melting ice, changing weather patterns, and rapid ocean acidification don't have emotions.

       You can be as alarmed or not, as you wish. What you can't do, if you want to be taken seriously (at least around here), is argue your case on the basis of misleading evidence (e.g. the material from Joanne Nova and Craig Idso), cherry picking (e.g. "ice-free Arctic in 2013" when the correct estimate is 2016 ± 3 years), and outright false claims (e.g. your comments about the "Hockey Stick", which others have noted has been substantiated over and over in the literature). If you persist in doing so you aren't likely to get any more polite reception than you are now.

       Personally speaking, if you don't find an unprecedented temperature change, in geological terms, alarming (or at least potentially alarming), that's your lookout. Frankly it seems that you don't have the slightest grasp just how rapid and significant a 0.7-0.8°C change in global mean temperature over a single century is.

       Regarding your (again, apparently reflexive) dismissal of 9+ metre sea level rise: the simple fact of the matter is that 9+ metre sea level rise would become inevitable, given sufficient unabated warming. It would take a few centuries to happen (even worst case scenarios for 2100 call for no more than 2 metres of sea level rise IIRC), but it would be inevitable (because, surprise surprise, ice tends to melt as temperatures rise, and there is a lot of ice locked up in the Greenland & Antarctic land ice sheets).

36834. Dikran Marsupial at 22:42 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren wrote "No more sacrosanct predictions of the future"

       again you are trolling, nobody is claiming that the IPCC projections are in any way sacrosanct.  Please give the hyperbole and rhetoric a break, it really is not helping you in any way.  The model projections tell us the consequences of our actions under our best understanding of the laws of physics.  To ignore them is to ignore what we know about the physics of the climate, which is an unreasonable and irrational position.

36835. Dikran Marsupial at 22:41 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       "Is your avoidance of the word alarming a cop out?"

       no, as I said earlier that future climate change is likely to be problematic and adaption expensive is sufficient to warrant efforts at mitigation.  By nature I am generally rather calm, rational person, so I may well not be alarmed by something that someone else would find alarming.  So I find it better to stick to the science than itroduce emotive terms such as alarming or CAGW etc.

       The warming that we have observed is not all we have to go on though, we also have the laws of physics, which you appear to ignore.  I consider that a fairly unreasonable attitude.

       BTW the meaning of "we know about the future" and "that does not mean we know nothing about the future" are not equivalent.  The former implies a much greater degree of certainty than the latter, and hence substantially misrepresented what I actually wrote.

36836. Warren Hindmarsh at 22:33 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       (snip)

       Moderator Response:

       [PW] Warren, this is your last warning: any further *trolling* and all your rants will be deleted, and you will be recused from any further commentary on SkS.

36837. Dikran Marsupial at 21:51 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       O.K., to show that Warren *is* just trolling, he complains 'Dikran sorry but to call me a troll and then you say you "know about the future" '

       what I actually wrote was

       "you are playing with words now. We can have no "evidence" of the future, but that does not mean we know nothing about it."

       I clearly did not say that I know the future, and to suggest that we are not completely ignorant of what will happen in the future is not an unreasonable statement.

       "once again your proof of alarming warming and we know "about 0.75c per century" is not that."

       Also I didn't say that I had proof of alarming warming.  I made it very clear that "alarming" is a subjective term and didn't use it myself, I also didn't say proof, you can't have proof of something that happens in the future. 

       It is sad that Warren should play such silly word games and misquote, rather than actually engage in a rational discussion of what the science actually does tell us.

36838. CBDunkerson at 21:47 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren wrote: "...the increasingly absolute belief systems of the AGW lobby (Mann's flawed hockey stick graph, climate gate, It won't snow in London again, the Arctic will be ice free by 2013, etc.etc.) caused me to adopt a contrarian and skeptical view."

       So you have based your position on lies and nonsense... and continue to hold that position even when shown that these things are lies and nonsense.

       Sorry, that doesn't make you a 'skeptic'.

36839. Warren Hindmarsh at 21:35 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Dikran sorry but to call me a troll and then you say you "know about the future" if that's the best you have sorry I'm too much of a contrarian skeptic to cop that now, once again your proof of alarming warming and we know "about 0.75c per century" is not that.

36840. Glenn Tamblyn at 21:23 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Tom

       I am aware the usual convention for any paleodata is 'present' is 1950. The GISP data I linked to specifically says from the present and is from a 2000 study. Possibly Alley means the usual convention, just the description of the data doesn't say that specifically.

       Warren's problem is relying on poor quality source for his arguents.

36841. Dikran Marsupial at 20:46 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren, the tone of your response to Tom is again snarky and gives the impression of trolling, rather than rational scientific discussion.  The answer is pretty obvious, the part that is not an extrapolation is not necesarily model based and hence the forcing data Tom gave is not "only a model".  Please exercise some self skepticism and try and see the value in the posts made by others, rather than just assuming they are wrong without checking.

36842. Tom Curtis at 19:32 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren Hindmarsh @29,

       1)  Could you please provide your evidence for your false claim that the forcing data I showed "is only a model"?

       2)  I note that your comment that even considering the possibility of mass extinctions in similar conditions to the worst mass extinction in the paleo record is "alarmist".  Very clearly you are operating on an a priori assumption that the impacts of global warming cannot be bad.

       You are making it more and more transparent that you are just yet another ideologically driven, evidence free troll.

36843. Dikran Marsupial at 19:30 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       By the way, the problems with Warrens behaviour here have been pointed out to him before, for instance here, where he wrote the obviously content-free trolling comment:

       Hi dikran

       where is the global warming :)

       To which I later replied:

       "Warren, firstly your posts on SkS have demonstrated an argumentative rhetorical tone. This is not conducive to discussion of science and is likely to irritate the other participants in the discussion, which reflects more badly on you than on anyone else. Please give it a rest."

       before going on to answer his question.  Note also the moderator comment that shows the other moderators had also tired of his snarky behaviour.

       I've had a look through Warren's posting history here, and this sort of behaviour seems pretty much standard operating procedure, so if he resents being labelled as a troll, then perhaps he needs to reconsider his posting strategy.

36844. Tom Curtis at 19:24 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Glenn Tamblyn @32, Before Present refers to before 1950 in geological analysis, unless otherwise specified.  Therefore the final date in the Alley et al data is 1855, not 1905.  A comparison between 1855 temperatures and modern temperatures at site of the GISP2 core can be found here.

       It is interesting to note that of the three regional temperature series, not one shows a temperature record through to modern times.  The GISP2 record shows temperatures only through to 1855 as already noted.  It even marks the temperature increase from 1790-1855 in red to deceptively indicate it is the modern warming.  

       The soil temperature record in the great plains (your second image in your post @37) terminates around 1500 AD, ie, effectively with the onset of the LIA.  The line across (as you note) represents modern values, but in fact represents modern (1990s) soil composition.  Soil is formed from biological decay products being worked into the sand and/or clay substrate by bioturbation.  Thus modern soil composition is only a measure of modern temperatures at very low resolution of at least decades and possibly longer.  This is shown, in part by the fact that 1940s measurements match 1990s measurements.  Therefore the modern values shown, used as a temperature proxy, equate to a multidecade average temperature terminating in the 1990s, and do not represent modern (early 21st century) values at all.    

       The final image (and your final image @37) shows no temperature post 1980.  The line across purportedly represents modern temperatures, but as you not is not the modern temperatures shown in the original source, and indeed shows a lower temperature than that shown in that source.

       Thus, in his attempt to show mid to late holocene temperatures greater than modern temperatures, Hindmarsh has singularly failed to show any modern temperatures.  So much for his claim to be guided by evidence.

36845. Dikran Marsupial at 18:58 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren wrote "Dikran I asked for evidence of alarming global warming"

       as I said, what is considered "alarming" is a matter of opinion, and like your use of CAGW is usually hyperbole or rhetorical overstatement in order to create a straw man.  If you want to give the impression of trolling, this is a pretty good approach.

       "you provided a link to a IPCC report. In that report it stated that the earth had warmed by "about 0.74C" over the last 100 yearrs""

       so?  did you read the projections of future warming?  That is what justifies efforts at mitigation, not the relatively small warming we have seen over the last 100 years.

       The IPCC reports also contain discussion of historical sea ice extent and the medieval warm period etc, but you seem to have ignored that and prefer Jo Nova's blog instead.

       "Yes there are models that predict much worse in the future but models, by their very definition, can not be evidence."

       you are playing with words now.  We can have no "evidence" of the future, but that does not mean we know nothing about it.

       "Dikan I resent the troll accusation"

       too bad, stop using the phrase CAGW, stop playing with words and start taking a balanced *skeptical* view of the evidence rather than just cherry picking images from blogs (without considering whether they are an accurate representation of the evidence or whether they tell the story they are purported to tell - see posts by Glenn).

36846. Glenn Tamblyn at 18:34 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren. Your first link (GISP) tells us about Greenland. The MWP (if there was such a thing) doesn't appear to have been global in nature. Certainly not if it was 500 years apart in different parts of the planet. Whereas warming today is global. And by not showing the instrumental record for Greenland in conjunction with the ice core data that removes the context wrt current temperature changes.Picture what that graph looks like if, at the far right the line climbs to current temps in Greenland. That would put it up at around the 'minoan' level, a much larger change than any of the other spikes given that we should be in a long term downward trend as the curved trend line on the graph suggests. Incomplete information can be very misleading Warren.

       Your second link was about evidence for differing proportions of different plant types in the Great Plains in the transition out of the last Glacial involving lots of factors. And if you read Nordt et al they show graphs from studies by others that differ significantlyfrom their work. So what was the point of the second link.

       And what excatly is Craig Idso's manipulation of the graph from Otto et al telling you about the reliability of your sources?

       And your links were all to the same source - Jo Nova. And she sourced 2 of them from Craig Idso.  And Idso manipulated both the images he supplied.

       You need to find better sources of information Warren.

        

        

36847. Glenn Tamblyn at 18:08 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren, regarding no Arctic sea ice by 2013, that was a projection by one modelling group and actually was 2016 +/- 3years.

       This is a graph of Arctic sea ice volume from PIOMAS since 1979. Each line is one month with the green bottom line being September. The bottom axis is zero volume.

       

       After last years mild season ice volume ticked back up so now the trend projection is saying 2016/17 for zero. Prior to last year the projection was saying 2015/16. Ice volume up there has returned to what it was a year ago - the 'recovery' has evaporated away. Will ice reach zero by 2016? Its not certain, but it is also quite plausible that it could.

       So '... but you still have to give me "Ice free Arctic"...'. What do you think the data is suggesting

        

36848. Warren Hindmarsh at 17:57 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Glenn Tamblyn Please read my comment again.

       I did provide links to 3 different locations..

       Yes they vary but they all have the same effect i.e, to hopefully allay composor99@26's concerns that recent warming was unprecedented in the "history of the earth" and yes your Vostok example should help composor99 as well.

36849. Glenn Tamblyn at 17:54 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren

        

       Regarding your 2nd link, this is a small excerpt from a paper Nordt et al here. Quite a technical paper about variations in the proportion of C3 & C4 plant in the US Great Plains over the last 12 kyr+

        

       Here is the conclusion from the paper:

       "Conclusions

       The delta 13C and delta %C4 from organic carbon of buried soils within the mixed and shortgrass prairie of the North American Great Plains permits a regional analysis of C4 grassland dynamics for the past 12ka. The delta 13C data compiled from a literature review of buried soils reveal that C4warm season grasses were present throughout the Great Plains study area during the past 12ka, but that there were appreciable fluctuations with 0.6 and 1.8ka periodicities. The crossover latitude of equal relative production of C4 and C3 plants appears to have been several degrees to the south of the modern location of 46 deg N prior to 6.7ka, with a shift to near the modern position after 6.7ka.

       Relative C4 production did not increase monotonically in response to orbitally forced insolation between 12 ad 6.7ka, apparently because of a negative feedback from the presence of the LIS, glacial lakes in the northern plains, and cool glacial meltwater pulses into the Gulf of Mexico and North Atlantic. Thereafter, fluctuations in solar irradiance provided a more direct influence on delta %C4 as outflow of warm subtropical air from the Gulf of Mexico became established, interrupted periodically by warm, dry westerly flow contributing to episodes of drought. Here, increased delta %C4 occurred during intervals of elevated solar irradiance and with shifts in the ITCZ into the northwest Gulf of Mexico in the absence of ice-rafting events in the North Atlantic.

       The coherency in our buried soil record with pollen spectra, marine cores, and ice cores, demonstrate the reliability of C4 plant dynamics not only as a proxy for grassland evolution but for climate as well. More work is needed to better understand grass dynamics in the early Holocene in response to conflicting reports of whether conditions were warmer or cooler than present. The paradox in the middle and late Holocene is that positive delta %C4 anomalies correspond with periods of dune activation. More work is needed to understand why during drought conditions C4 plants flourished. No doubt, C4 plants were responding positively to elevated temperatures as they should, but either these grasses thrive during drought or were growing between drought events during periods of landscape stability.

       Hopefully our work will spawn further investigations into grassland dynamics of the past, provide additional parameters for climate and biome modeling, and create a better understand C and N dynamics in a region that is poorly understood"

       So what exactly is the relevance and more importantly significance of your 2nd link?

       Then there is this graph from Nordt et al. Seemingly one of the graphs that your graph was based on.

       

       
       Whereas your looks like this:

       

       Sort of a bit different isn't it when you leave half the data off. Because the Nordt paper was looking at some quite complex local climatic issues as the Laurentide Ice sheet melted and so on. Again not exactly global.

       So who produced this truncated graph that could o easily mislead people? Well lets quote Jo Nova "Thanks to the Craig Idso at CO2Science for compiling so many of these on his site.". Interesting concept don't you think. Truncating graphs and cherry-picking is 'compiling'?

       As to your third graph and some more from Craig Idso, try reading this.  Note particularly the section labelled CO2 Non-Science on how CO2Science misrepresents Oppo el al (2009).

       Here is your graph as shown in Otto et al (b)

       

       Notice the '1997-2007 mean annual SST' line that Craig Idso at CO2Science 'compiled' away in your version and replaced with another line that is not on the original, is not identified, and might suggest well sumfink or uver.

       

        

       Finally Warren. If you wish to discuss science here with people that's great. But please make them your opinions or the published science itself. Not a blogger said that another blogger said that ... well you get the picture.

       Just doing a copy and paste from an old Jo Nova blog doesn't really count as making your own argument does it? Its sort of insulting to everyone here.

36850. Dikran Marsupial at 17:43 PM on 7 May 2014
       Brandis confuses right to be heard with right to be taken seriously
       

       Warren, the claim that the Arctic may be ice free by 2013 was made by one (1) scientist, the IPCC reports (and the majority of Arctic sea ice scientists) did not agree with that projection.  So what you are doing is cherry picking headlines and not bothering to check whether they were actually in accordance with the mainstream scientific position. 

       Here is a hint, if you think some climate change claim is alarmist, try looking to see what the IPCC reports say about it.

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