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Comments 36351 to 36400:

36351. grindupBaker at 09:55 AM on 10 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       Skeptical101 #14 My interpretation and synopsis of the considerable technical detail and references provided by Tom Curtis #15 & One Planet #16, #17 is that your "...not use it as an argument to support AGW" is correct if used over periods in which short term natural variability influences the trend strongly (<30 years was mentioned sometimes) and, in particular, the models are not able to predict the ENSO conditions at all well. However, over the somewhat longer term of several decades or more it'll all average out and leave the trend. I recall some article about South Pacific Easterly winds strengthening the last "couple decades or so" (?) and pushing more heat down into the South Pacific than might have been expected. I find that graph that's often on SKS per Tom #15(2) to be quite illuminating and I keep trying not to mention that it makes me wonder whether El Nino years are pulling away from La Nina & neutral since ~1991 with El Nino at 0.23 Celsius / decade because I know the data since then is too sparse and varied and definitely <30 years. If I'm right in 30 years hold a seance and tell me about it.

36352. Rob Honeycutt at 05:02 AM on 10 May 2014
       Earth's five mass extinction events
       

       Varika...  The comment you're responding to here is discussing the difference between tectonic and volcanic emissions in the Cretaceous to tectonic and volcanic emissions now, excluding human emissions.

       Man-made emissions of CO2 are about 100X that of natural sources. 

       http://hvo.wr.usgs.gov/volcanowatch/archive/2007/07_02_15.html

36353. Varika at 04:57 AM on 10 May 2014
       Earth's five mass extinction events
       

       Sorry, I'm used to forums where I don't have bold/italics options.  I will use those in the future here.

36354. Varika at 04:20 AM on 10 May 2014
       Earth's five mass extinction events
       

       "Eruptive tectonic activity (volcanoes; igneous province eruptions etc.) were active during much of the Cretaceous at a level that resulted in raised greenhouse gas warming and an increase in the carbon cycle at a rate around double that of present."
       
       Alright, I'm confused.  If the Cretaceous had carbon cycle increases at a rate double of the present, that means that volcanoes were putting out twice what's being put out today at any given time, right?  So if that's true, how can we cause a faster acidification of the oceans when we are putting out less carbon per year than those volcanoes?

       Moderator Response:

       [RH] Please note that we would prefer people not use all caps for emphasis, as it tends to read like shouting. Please use the bold or italics tools at the top of the comment box to add emphasis. Also, make sure you read the commenting guidelines.

       All caps changed to bold.

36355. Dikran Marsupial at 03:31 AM on 10 May 2014
       There is no consensus
       

       bakertrg wrote "so 97% of scientists are taking the position that THE cause of global warming is anthropogenic but none of them are publicly stating that humans are the cause of climate change? Maybe I'm missing something but that seems to contradict itself."

       do yourself a favour and go and read the paper and the comment thread to see what has been discussed already.  Most papers on climate change are independent of whether the cause of the change is anthropogenic or natural.  To give you an example, I have worked on statistical downscaling, which attempts to estimate the effects of large scale atmospheric circulation (which GCMs model fairly well) on local (e.g. station-level) scale (which GCMs fundamentally can't do beause the grid boxes they use are too large).  A paper on statistical downscaling doesn't need to make any statement at all on what causes climate change because that is not what the paper is about and academic papers tend not to make assertions that are not directly justified by the analysis given in the paper.  There are many other topic in climate change that are not concerned with attribution, which is why relatively few explicitly take a stance.

       Now this will be obvious to anybody that understands the culture of scientific publication.  Scientists do have better things to do with their time than answer questions raised on climate skeptic blogs, and as a result, you will only generally be assured of a climate change paper taking a stance on the cause of the change if the subject of the paper is an attribution study.

       "Despite what it may appear to be my goal is to find answers. "

       Then perhaps next time someone answers your questions, you shouldn't accuse them of being disingenuous and copping out.  This is especially true if you are going to convert

       "97% of the papers that take a position on the question do take the position that it is mostly anthropogenic."

       and

       "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"

        into

       "97% of scientists are taking the position that THE cause of global warming is anthropogenic"

       EMPHASIS yours.

36356. MA Rodger at 03:20 AM on 10 May 2014
       It's cooling
       

       jetfuel's numbers for ASIV make no sense whatever unless it is about the state of the Arctic back in early November 2013 & the numbers are not meant to be exact.

       @218 jetfuel states "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." Since the summer 2013 minimum, PIOMAS has never shown numbers higher than 2,620 cu km (ie GTonnes) above the previous year. That was back at the beginning of November 2013, more Autumn than Winter. That difference has been shrinking since then & since the beginnng of March 2014, ASIV has been lower than the 2013 equivalent. This '2200 cubic miles' figure is ~9,000 cu km. That was the value of ASIV back at the beginning of November 2013.

       As for the relevance of these numbers - pass.

36357. Dikran Marsupial at 02:42 AM on 10 May 2014
       It's cooling
       

       jetfuel, I demonstrated that the "recovery" was actually just a continuation of the downward trend in March maximum sea ice extent, and that an increase in the winter gain is what is expected simply because March sea ice extent is declining a bit more slowly than the September minimum extent.

       There is nothing special about the recovery in the last three years.  If you disregard the evidence and cherry pick in this manner, don't be surprised if your assertions are viewed with skepticism.

36358. John Hartz at 02:40 AM on 10 May 2014
       It's cooling
       

       jetfuel:

       Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

36359. Composer99 at 02:15 AM on 10 May 2014
       It's cooling
       

       jetfuel:

       Do you think that Arctic maximum extent is the only factor determining the behaviour of the polar vortex? Yes or no?

       If yes, can you justify this position?

       As far as your comment on the ice volume goes, PIOMAS anomaly data show ice volume has dropped by approximately 10,000 km³ since 1979. An 800 km³ increase in one year (and there are plenty of upward jolts in the data even as it follows the downwards trend) is much too short a time period to start speaking of a "recovery".

       I have reproduced the graph below:

       

36360. jetfuel at 01:47 AM on 10 May 2014
       It's cooling
       

       nsidc data shows late March peaks of 15.22 million sq km for 2012, 15.1 million for 2013 and 14.9 million for 2014. The 1981 to 2010 avg is 15.4. The avg of 2012-2014 March peaks is 2.13% below the 1981-2010 avg peak of 15.4 million. 2.13% less ice area is the reason the Polar Vortex fell apart? The other 14.9 million sq km of ice couldn't save the vortex? Then, why hasn't this Vortex disintegration happened nearly every other year? Area with at least 15% ice is a rough indicator. the tremendous increase in ice volume in 2013 and 2014 also needs consideration. 2014 saw an 800 cubic mile seasonal increase in sea ice volume. That's the source of the 'recovery' I spoke of. For me to believe the 'polar vortexfell apart' line, I'd expect 10% less ice volume compared to last year, not 1.3% less ice area (14.9M vs 15.1M sq km) and a volume increase.

       Moderator Response:

       [JH] What is the basis of your "10% less ice voume" metric? Is it merely your personal opinion, or is it based on sound scientific research?

       In case you have not noticed, personal opnions about science carry very little weight with the users of this website.  

36361. Tom Curtis at 00:03 AM on 10 May 2014
       There is no consensus
       

       franklefkin @598, thankyou.

       I should have checked more closely before responding to the latest denier cherry pick on temperatures.  As it stands, my claim that bakertrg's claim re 21st century trends being "trivially false" needs to be withdrawn.  It is merely obviously false.

       Obviously false because, firstly, with five established temperature records, claiming a negative trend with two of them show a positive trend is begging the question as to which record is superior.  We can, off course, look for a tie breaker among the records.  Noticing, however, that the only surface record with truly global coverage, and the satelite record with the greatest covered area both show positive trends shows the negative trends of the others to be due to information they exclude rather than a property of global temperatures.  Further, the fact that newer records (HadCRUT4-hybrid, BEST) also show positive trends corroborates GISS and UAH as showing the better record, as do indirect measures of temperature such as Sea Level rise, and receding glaciers.

       Alternatively, we may decide to treat all records alike, and simply take an average - except that the average of the 5 established records gives a positive trend - and including the newer records (HadCRUT4-hybrid; and BEST) makes that postive  rend even stronger.

       Finally, we need only notice that pushing the start date of the trend back one year (two years for RSS), or the end date back to Dec 2010 to make the trends positgive to see that the negative trend even in those records with the trend depends essentially on a chery picked period.

       Regardless of all this, it appears that bakertrg has dropped that claim, so this is now beside the point.

36362. chriskoz at 20:11 PM on 9 May 2014
       2014 SkS Weekly News Roundup #19A
       

       Thanks for the encouragement Rob,

       Sure I can find time to compose something over this weekend. I dunno how to submit, I guess I contact John once I have something...

       Moderator Response:

       (Rob P) - Sounds like a plan. Whenever you're ready.

36363. Dikran Marsupial at 19:33 PM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       jetfuel wrote: "Looking at Post #5's Graph above, the 2006 peak is about 2mm below the 2011 valley. I would draw a new best fit curve starting in 2006 that shows an 8 mm rise in 6 years, or 1.33 mm/yr."

       The human eye is only too good at finding patterns in noisy data, even when they don't actually exist.  That is why statisticians have invented methods for this problem, variously known as "breakpoint analysis", "broken stick regression", "segmented regression" etc.  What these methods do is determine whether the improvement in the fit of the model justifies the additional model complexity introduced by adding a breakpoint, which introduces at least two additional parameters to the model.

       If you don't follow standard statistical practice in this way and just pick the breakpoints by eye, you will generally end up overfitting the data and drawing meaningless conclusions based on the noise.  It is the sort of thing that is a recipe for confirmation bias.  So while you might do that, a scientist probably would know better.

36364. Glenn Tamblyn at 18:42 PM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       Stephen, a significant part of the dip in 2011/12 ended up in Australia. Lake Eyre and several other lakes in Central Australia filled for the first time in years - flamingo heaven. Then slowly evaporated away over the next 2 years.

36365. Doug Bostrom at 15:39 PM on 9 May 2014
       As Population Surges, Harsh Climate Of Southwest Will Only Get Harsher
       

       If you're interested in water issues affecting the SW US you'll want to follow John Fleck's Inkstain.

       Fleck's a journalist in New Mexico, where water can't be taken for granted, is the subject of barely civil interjurisdictional struggles for partitioning and is generally sufficiently fraught to require a beat reporter.

36366. Stephen Baines at 15:27 PM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       Thanks TC for the updated graph.  Yes I was referring to the trend line you would get from the graph in the OP.  It's not surprising that with more data you get reversion to the mean trend line.

       The recent large fluctuations around that mean trend are pretty interesting though.  I remember the decline was attributed to La Nina transporting water to temporary storage on land, but I haven't read anything really recent on that.  Even the large La Nina in 98-99 didn't have as big an effect.  I should look it up.

36367. Tom Curtis at 15:03 PM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       jetfuel @39, Stephen Baines @40, here is the most recent update of sea level increase from the University of Colorado:

       

       As you can see, the trend from 1993 is still 3.2 mm per annum.  Clearly jetfuel's prediction of a trend of approximately 1.33 mm per annum is inaccurate.  I suspect Stephen Baines prediction of an increased trend since 2006 is also inaccurate, but that is not so obvious.  (It is more likely to have been accurate to early 2013 as in the OP.)

       Looking at the great lake data, Lake Ontario rose 0.11 meters between April 2013 and April 2014 inclusive, but fell 0.05 meters from May 2013 to April 2014, the actual one year "rise".  Even the former is no where near record breaking, being near one eigth the 0.86 meter rise from Dec 2012 to July 2013, although that does have a large seasonal component.  There have been larger seasonal and annual increases in the past. (For data, follow Stephen Baines' link.) 

36368. Stephen Baines at 10:24 AM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       Jetfuel...your approach would almost certainly seriously underestimate the sealevels for 2012 and 2013 presented in the updated graph in the OP, since starting in 2006 looks like it would give you a steeper slope than the 3.2 mm /year overall average.  Which is why we don't draw regressions on small subsets of the data, especially cherrypicked ones.  Why would you take the trouble to go through the comments and ignore the updated graph anyway?  

       With regard to lake levels, there has been little net change in level of the Great Lakes over the time frame of the sealevel observations.  That includes this year.  You must be thinking about seasonal changes, but those are irrelevant to sea level change since they are ephemeral.  Also this year does not seem unusual when you look at the data.

       BTW moderators, the link to the updated version of the fisgure in comment 5 appears to be broken.

       Moderator Response:

       [DB] Fixed.

36369. John Hartz at 08:22 AM on 9 May 2014
       There is no consensus
       

       bakertg: 

       Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

36370. jetfuel at 08:12 AM on 9 May 2014
       Sea level rise predictions are exaggerated
       

       Looking at Post #5's Graph above, the 2006 peak is about 2mm below the 2011 valley. I would draw a new best fit curve starting in 2006 that shows an 8 mm rise in 6 years, or 1.33 mm/yr. With all that I've read lately about the cold 2012-13 and 2013-14 northern winters, I'd venture to say 2013 and 2014 would follow the 1.33 mm/yr line. Hardly the makings of flooding Florida, where I lived for 17 years in a house that is 14 feet above sea level. There's only so much water in the Olagalla aquifer, and when it is 70% empty in 2060, the rate of draw from it falls off a cliff. Then there's the huge increase in Great Lakes water levels this year. An unbelievable record increase in Lake Ontario and 14 inches added to Superior. Just Superior's gain offsets 7/33 of all land based melt from Antarctica. (cubic miles fraction for 1 year)

       Moderator Response:

       [JH] Please explain exactly how you did your "curve fitting" and provide the sources for the data that you have included in your post. Until you comply with this request, your future posts will be deleted.

36371. Stephen Baines at 08:03 AM on 9 May 2014
       There is no consensus
       

       I have said this before…the idea that the consensus is evidence of some sort of greed-induced conspiracy among scientists completely baffles me as a scientist. Yes, individuals care about getting grant money to support or students and technicians, but it’s not like we are all friends and family living off a common bank account. We often criticize each other strongly, sometimes with vitriol, about things noone else seems to care about. We compete with each other for limited money and review each others grants, sometimes agressively.

       If I sense someone is falsifying results, I have every incentive in the world to attack them, especially if they are doing different research than I and getting money that I could get. Heck, I even get famous if I overturn their accepted wisdom. And I could make much much more being a shill to vested interests who would prefer we deny climate change. If money were really the main factor here you’d see a lot less of a consensus.

       The fact that I do not know a single scientist who rejects the idea of AGW, despite differences I have with them on a multitude of other issues, is an indication of the power of the scientific arguments supporting it, and the commitments of scientists generally to following the evidence. Nothing in any of the surveys is inconsistent with that impression.

       Contrary to bakertrg’s cynicism, I find it all rather uplifting. If only I could figure out why bakertrg hates me, I’d be a happy camper!

36372. Rob Honeycutt at 06:31 AM on 9 May 2014
       There is no consensus
       

       bakertrg...  Please note that moderation complaints get deleted.

       If you challenge a piece of published research, do so by backing your statements with references. If you think Doran was a poor survey, show references that confirm it was poor methodology. Don't just state it with opinion, present why you believe that to be the case. Show research on survey methodology that states why the results are not robust.

36373. KR at 05:44 AM on 9 May 2014
       There is no consensus
       

       bakertrg - Also note that Anderegg 2010 (which you seem to be criticizing by proxy in your last post) used completely different methods than Doran 2009, or Cook et al 2013, or Oreskes 2004.

       Yet _all_ of these studies found an overwhelming consensus among scientists, driven by the evidence they they know of, that the dominant cause of recent climate change is anthropogenic. And replication via different methods is one of the foundations of good science. 

       Unless you can present evidence (you know, actual data) that this consensus does not exist, I'm going to have to conclude that (a) you're wrong about the consensus, and (b) you're suffering from confirmation bias and are just not interested in the facts. 

36374. KR at 05:33 AM on 9 May 2014
       There is no consensus
       

       bakertrg - I expect you will be subject to moderation, due to claims that people are presenting deceptive opinions due to financial renumeration. That said:

       Although Spencer Weart has expressed concerns about a particular study (Anderegg et al 2010), you do not appear to have read his actual comment, which states:

       The statistics are certainly interesting, but must be interpreted as "2-3% of people who have published 20 climate papers are willing to publicly attack the IPCC's conclusions." That is, to me, a surprisingly high fraction...

       If Weart feels that 2-3% rejecting the consensus is a high number, he is hardly disagreeing, now is he? It appears his concerns were with the methods of that particular study, and not the conclusion of an overwhelming consensus. Curiously, you present your information linking a website that appears to be a blog from someone in climate denial, which only reinforces the impression that you, too, are in climate denial. In fact, the more you write, the less interested (IMO) you appear in actual science. It's rather sad that the only lesson you take from Weart is an out of context of a single paper, rather than the copious work on the basics of climate change that I pointed you to. Your reading appears to be rather selective...

       Incidentally, Dr's Spencer and Lindzen are quite familar names, as they have quite a history of climate denial themselves - see here and here.

36375. Dumb Scientist at 05:16 AM on 9 May 2014
       There is no consensus
       

       A cursory glance at Cook et al. 2013 shows that only levels 1-3 are included in the consensus; they explicitly or implicitly agree that most of the warming since 1950 is anthropogenic. A cursory glance at Dr. Spencer's claims places them somewhere in levels 5-7, which aren't part of the consensus.

36376. bakertrg at 04:43 AM on 9 May 2014
       There is no consensus
       

       (snip)  Despite how my posts are being characterized I'm not intent on being a dissenter I am just skeptical of some of what is here and any website pushing that 97% number so hard and calling it the consensus makes me VERY skeptical of both the message and the messenger.
       
       Sorry if I offended you with my retort Dikran, not my intent but I felt you totally mischaracterized my post drew a conclusion I never made and sent me off to read sources that don't refute my point, aren't relevant to the issue and actually support my position not yours.

       (snip) One of his arguments was that the papers in the 97% number actually don't say man is the main cause of global warming... which is exactly my leaning.  I'm not emotionally vested in this idea, it's just the best answer from the data I have actually researched.  

       dikran 593: 97% of the papers that take a position on the question do take the position that it is mostly anthropogenic.

       next paragraph 

       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

       so 97% of scientists are taking the position that THE cause of global warming is anthropogenic but none of them are publicly stating that humans are the cause of climate change?  Maybe I'm missing something but that seems to contradict itself.

       Despite what it may appear to be my goal is to find answers.  I am skeptical of some of the things that are held to be incontrovertible here. My main question and the reason I'm posting on this thread is because I strongly disagree with the methodology for coming up with the number 97%.  It seems that a lot of scientists think that humans are A cause of global warming and the graphic takes a huge liberty with meaning by saying humans are THE cause.  The meanings are vastly different.  I have tracked down some of the papers I'm going to see how many say THE cause.  

       I'm not a climatologist, I do have a background in physics, computer science and engineering, I have no dog in this fight other than I truly want to know what is happening on our planet if not solely for my edification so that I can at least educate my kids to the best of my ability and speak intelligently on the subject which potentially has massive ramifications going forward.  In any event I am honestly trying to address each counter to my initial post (despite what is pretty close to being dog piled which is my reading comprehension is any good turns out to also be against the comment policy)
       
       I see the words "easily disproven", but I actually thought it was accepted fact that we have had cooling trends during the modern industrial period despite ever rising CO2 levels. I posted 1900 to 1940 because I believe I read that on this website but in actually going to look I found some different time lines that had downward trends.  1880 to 1915 or 1940 to 1975 would have been a better example for me to use, I stand corrected.

       http://www.geocraft.com/WVFossils/last_200_yrs.html
       
       In any event, the point still remains the same, if the CO2 level is constantly rising and the causation is as great as is being purported shouldn't we see an accelerating temperature change?  According to information IPCC admittedly can not explain temperature has been flat for the last 17 years.  That is very difficult to explain if the problem is accelerating and even suggests that the causation is either much smaller than alarmists suggest (small enough that mother natures natural variance swallowed it whole) or the link to causation is less strong than you're suggesting.
       
       dr don easterbook gives a fairly informative view both in text and video (though my research shows that he has taken money from the koch brothers) sadly, many players in this discussion have taken funding from one side or another and/or have a book centric profit motive to push their beliefs.  Richard Lindzen also falls in this same space.  Unfortunately it's hard to determine what came first the ideology or the funding, of course the non consensus supporters are going to look for scientists who share their ideology to champion the cause so it's not surprising that the guys who get funded by big business have the anti AGW ideology.   (snip) 
       
       The video is long but interesting and he does seem to have quite a bit of data.  video  the text can be found here and has a lot of great information.  Dr Lindzen also offers some pretty compelling video's and his credentials are top notch.  That being said his monetary incentive made me watch both videos with a very jaundiced eye.  I found him to be pretty credible but I'm always skeptical of people getting paid for their science by a source that only wants a specific outcome.  
       
       KR - I briefly looked at Spencer Weart and despite being a believer in global warming comes out against a recent argument for the consensus here.  His post about the flawed assumptions in the paper from PNAS made me think he's at least interested in being objective. A very telling point of his post (made on this very website) here poses a big problem for the 97% number.  He states that while he is convinced by the evidence, he is surprised by the number who are not.  Doesn't appear as if he believes it's only 3% dissenting.  He pointed to several reasons why that number could be skewed and he's a recognized figure on your side of the argument.

       Moderator Response:

       [TD] See "CO2 Is Not the Only Driver of Climate," and if you want to discuss that topic do so there or on other relevant threads, not here.  You are incorrect that there has been no warming in the past 17 years; there are many relevant threads for that topic, but you might start with "What Has Global Warming Done Since 1998?".  Further discussion of those topics on this thread will be deleted without warning.

       [TD] Don Easterbrook is most definitely not "informative."  Just one of many places where his inaccuracies are revealed is here.  Richard Lindzen's errors are numerous; one explanation is here.

        

       [PW] Your moderation complaints have been snipped, and you've been given Warning #1: You continue to argue in bad faith, you continiue to play word games, you continue to misrepresent other poster's words, and you impute dishonesty from them, too. Cease, or Warning #2 will be your last.

36377. Rob Honeycutt at 03:58 AM on 9 May 2014
       There is no consensus
       

       franklfkin... It would be incorrect to call those negative trends. None of the trends you listed can be determined to be negative since they can't be statistically determined to be different than a zero trend. 

       GISS: 0.022 ±0.157 °C/decade (2σ)

       NOAA: -0.003 ±0.145 °C/decade (2σ)

       HadCRU4: -0.009 ±0.141 °C/decade (2σ)

       HadCRU4hybrid: 0.054 ±0.188 °C/decade (2σ)

       RSS: -0.060 ±0.252 °C/decade (2σ)

       UAH: 0.054 ±0.252 °C/decade (2σ)

       One thing I'm just noticing that is interesting, the RSS and UAH data, which originate from the same satellite data, are almost identical except for the "-" sign.

36378. Stephen Baines at 02:49 AM on 9 May 2014
       There is no consensus
       

       bakertrg

       I agree with others that you need to read a lot more with an open, if critical (but not cynical!) mind.

       If you agree global warming is happening across the atmosphere, oceans and cryosphere all together, then you are forced (due to conservation of energy) to presume that the heat balance for the planet is changing. There are only three ways that change can happen: increasing output or radiation from the sun, reduced albedo due to lower atmospheric aerosols, and increasing greenhouse gas concentrations. All other causes of net heating that we know of are trivial.

       The warming since 1970 has occured despite no net change in solar output, and maybe a slight decline. There was also fairly frequent volcanic production of aerosols that should have cooled the earth. The only major forcing that changed over this period were greenhouse gases (CO₂, CH₄, N₂O). The lack of correlation between warming and the other natural factors that could warm the earth is just as important as the correlation of warming with CO₂.

       Scientists aren't satisfied with that though. They also found the effect of CO₂ on climate is entirely consistent with physics — in fact this knowledge predates the correlation between CO₂ and temp. You simply cannot build a physical climate model that reproduces the current warming from variations in solar radiation and volcanic aerosols alone. People have tried.

       Scientists then found fingerprints in the stratospheric cooling, spectral profiles of IR emission to space and back to earth, and in relative heating of nights and days that are consistent with hypothesis that the change is due to the greenhouse effect. The warming is also consistent with climate sensitivities estimated from warming events in the historical past, and in the paleo record.

       So, to argue against the observed changes being anthropogenic, you are left to somehow argue that CO₂ is not human derived. Unfortunately, the human origin of atmospheric CO₂ has been proven beyond doubt using multiple lines of evidence well before the IPCC was even formed - in fact that knowledge was one of the reasons the IPCC was formed!

       That is the basis of the scientific consensus. You have to realize that sometimes scientific findings align simply because nature is giving us a clear signal, and this is one of the clearest I've seen in my experience as a scientist.

36379. Composer99 at 01:48 AM on 9 May 2014
       There is no consensus
       

       bakertrg:

       Your posts give me the impression that you are badly overstepping your subject matter knowledge, your claims to the contrary notwithstanding. They also give me the impression that you aren't sufficiently skeptical regarding the claims advanced by climate science deniers, your claims to the contrary notwithstanding.

       For example:

       There really is very little evidence to support the claim that it's (CO2 emissions) causing global warming on a massive scale when we're simply not experiencing global warming beyond what has repeatedly been experienced in the past.

       Completely incorrect.

       (1) In this recent article, Dana provides a summary of several attribution studies, which quantify the contribution of anthropogenic effects vs. the contribution of natural effects over the past 50-65 years. You will note that most of the anthropogenic contributions either hover around or well overshoot 100% (because natural effects over that time period have been causing cooling).

       (2) How do you know "we're simply not experiencing global warming beyond what has repeatedly been experienced in the past". Sources, please. What is more, past global warming has included both minor and mass extinction events (e.g. PETM, Permian-Triassic extinction) so even if current warming is in line with what's repeatedly been experienced in the past, it doesn't follow that either the process of warming or the end result are desireable from the perspective of maintaining an advanced, affluent, complex human society based on creating reliable surpluses of food for 7.5+ billion people.

        

       As for this portion of your specific response to me:

       One of the confusing things on this subject is the interchanging of terms "global warming" and "climate change". I'm guilty of this myself, typically global warming or Anthropomorphic Global Warming (AGW) has a negative connotation and puts the cause of change squarely on man and typically makes the supposition that the change is massive and catostrophic.

       As a matter of fact, global warming as a technical term is a subset of (global) climate change. If the global climate is changing, and the change is the result of an increase in the global temperature, global warming is an accurate description. Adding anthropogenic to the term merely (and accurately) indicates the cause of the warming. What is more, the political decision to split hairs over the two terms was launched, not by Al Gore or environmentalists, but by a Republican political strategist to sow confusion about the subject. See here for details.

        

       The bottom line is that you are coming across as:

       -  being ignorant (as in lacking sufficient knowledge) of the topic,

       -  projecting your lack of knowledge and biases onto others (and especially onto the actual body of evidence), and

       - tiresome to deal with, since many of your claims are trivially easy to recognize as faulty, flawed, or outright false, but require a great deal of hyperlinking and typing to address publicly (hence the Gish Gallop).

36380. Composer99 at 01:03 AM on 9 May 2014
       There is no consensus
       

       franklefin:

       bakertrg wrote the early 20th century, so I am assuming that Tom Curtis meant to issue his point with respect to that timeframe, and the change in centuries is inadvertent. But Tom can clarify if I'm wrong.

       (I'm sure one can find a brief cooling trend here and there in the early 20th century, perhaps even a statistically significant one - in fact, I used GISTEMP from 1900 to 1910 and got a trend of -0.270 ± 0.263 °C per decade over that timeframe. But the point of the exercise is to get bakertrg to actually support his arguments.)

36381. One Planet Only Forever at 00:34 AM on 9 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       @Skeptical101,

       As a follow-up to my previous questions: After reviewing the pattern of ENSO magintude do you understand that it is a rather random pattern that would not be easily predicted? And if so, do you acknowledge that any modeling into the future would be best done based on an ENSO Neutral condition rather than trying to speculate about the pattern of the ENSO fluctuations?

       Another consideration is that the explanation NOAA provides for how they establish the baseline for ONI values points out that the ONI neutral ocean surface in the region the ONI is monitored has been increasing. This is the reason the ONI values table is headed as being based on the latest baseline, with a link to the previous baseline table of values.

       Hope this helps you better understand what is going on.

36382. KR at 00:26 AM on 9 May 2014
       There is no consensus
       

       bakertrg - That's quite a Gish Gallop of disproven memes you've posted, and indicate that you have not been reading up on the topic. I would suggest looking through The Discovery of Global Warming by Spencer Weart, which is quite approachable. 

       Long story short, if you are actually interested in the science, I suggest you read up. Your claims are seriously in error. 

       If you are interested only in dismissing the conclusion that we're responsible for climate change (as hinted at by the amount of rhetoric in your posts) you're barking up the wrong tree. The overwhelming consensus on the topic is due to the overwhelming evidence supporting it, and reality cares not one whit about your preferred conclusions. 

36383. One Planet Only Forever at 00:05 AM on 9 May 2014
       Answers to the top ten global warming 'skeptic' arguments
       

       @Skeptical101,

       I would like to know if you accept the following fundamental points about this issue:

       • El Nino events can temporarily significantly bump the global average surface temperature up from the value it would have been if ENSO was neural, and that the amount of the bump depends upon the timing, strength, and duration?
       • La NIna events can temporarily significantly bump the average down from the value it would have been in ENSO was neural, and that the amount of the bump depends upon the strength and duration?
       • Volcanic dust can temporarily significantly bump the average down from the value it would have been if a case like 1998 when there was very little volcanic dust in the atmosphere?

       If you accept these points then the only issue becomes the magnitude of their influence. Without statistical analiyis it is possible to see the possible relationship between ENSO and temperature. The following site shows the measured magitude of El Nino and La Nina.

       http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

       There is a pretty clear correlation between the ENSO changes and global average surface temperatures in all temperature sets. Even Dr. Roy Spencer's chart of the temperature values he has interpretted from satellite data points out the 1998 El Nino at that bump.

36384. franklefkin at 23:35 PM on 8 May 2014
       There is no consensus
       

       Tom Curtis,

       NOAA, HADCRUT4, & RSS.  Start date 2001, end date 2014 all give neg trends.

36385. Tom Curtis at 23:21 PM on 8 May 2014
       There is no consensus
       

       bakertrg @594, running of a list of trivially easy to refute denier memes is hardly going to convince us that your front as a sincere inquirer is genuine.  Rather than run through the whole GISH gallop, I will take just one:

       "...how was temperature dropping in the early 20th century despite rising CO2 levels"

       I assume you are not going to pretend that you were asking us to explain something which you believed to be false.  Ergo you have claimed that temperatures have fallen over the early twenty first century.  So, by what measure?

       I'll make it easy for you.  In the upper left margin you will find a button labelled "trend calculator".  Press it, and tell me which of the temperature records shows a negative trend in the 21st century.  Tell me the data set, the start date and the trend.

       If you cannot find one, publicly admit that you have made a trivially false claim that was easy to check.  You have in fact proved that your critical faculties work only one way in this debate.  Admit that to yourself and you may have a chance of becoming genuinely skeptical.

36386. bakertrg at 23:06 PM on 8 May 2014
       There is no consensus
       

       composer you're equating two things that are not the same.  No one credible is stating climate change is not happening, the quote you have regarding "global warming is a hoax" is in regard to the alarmist global warming mantra being pushed by Al Gore and the like.  That it's a man made phenomenon (AGW if you will) and threatening to destroy the planet.  So matural climate change is definitely happening the argument is are we expereincing potentially devestating global warming that is man made, irreversible and a serious threat to life as we know it.
       
       When I said no one is arguing that climate change is happening I was refering to the never ending cycle of climate shifts the earth has seen. We're currently in a warming cycle but this has happened repeatedly for as far back as we can find evidence (trees in the geologic short term and ice cores for a more extended view.)
       
       One of the confusing things on this subject is the interchanging of terms "global warming" and "climate change".  I'm guilty of this myself, typically global warming or Anthropomorphic Global Warming (AGW) has a negative connotation and puts the cause of change squarely on man and typically makes the supposition that the change is massive and catostrophic.  
       
       The IPCC is not convincingly unbiased, I have read much of what they have to say but they have been impugned on numerous fronts, not to mention they attempted to sweep data that undermines there arguments under the rug.  That's not good science.

36387. Dikran Marsupial at 23:02 PM on 8 May 2014
       There is no consensus
       

       bakertrg wrote "I find it pretty disingenuous to make the argument that scientists "have something better to do..." seems like a convenient story."

       sorry, *I* have better things to do than attempt to discuss science with those that immediately accuse me of being disingenuous because they can't answer the point.

       Now if you feel that there is evidence that shows that the rise in CO2 has not resulted in an increase in temperature, then please present that evidence on the appropriate thread (this one is for discussion of the concensus, not the phsyical science).  But please do so without the hyperbole, I am interested in science, I am not interested in rhetoric.

36388. bakertrg at 22:54 PM on 8 May 2014
       There is no consensus
       

       I'm not sure why you seem to think otherwise, but I totally agree on the CO2 being part of the greenhouse effect, my argument is the change in CO2 is not convincingly correlated to climate change on the level that is being put forth.

       So we're clear, everyone is in agreement that the climate is currently shifting warmer and the greenhouse effect is a real thing. The dispute is if man made emissions are causing that shift more than nature. There really is very little evidence to support the claim that it's (CO2 emissions) causing global warming on a massive scale when we're simply not experiencing global warming beyond what has repeatedly been experienced in the past.

       As of 2001 humans had only changed the CO2 levels by 100ppm, I'm sure it's 200 ppm or more by now (I read somewhere we're increasing the number by 2 ppm per year but forgot where), but 200ppm is a miniscule fraction of the greenhouse gases as compared to water vapor for instance. Once again if CO2 is such a sure thing for causation (not simple causation but THE significant causation) how was temperature dropping in the early 20th century despite rising CO2 levels? I fully understand the greenhouse effect, that's not the debate the debate is that the relatively small change in greenhouse gas density is massively impacting global climate and that AGW is definitively the cause of a massive change even though we're still in a place that is fully within the expected variance defined by historical record.

       Does that make sense? Your argument is that we're in a massive man made climactic shift but we're not even outside the boundaries of what we have regularly seen in the past, when man made influences were not present. Kind of like making an argument about the massive effects of the steroid era in baseball if no one was actually hitting more home runs. MLB had a sudden statistical shift in home runs by a statistically significant number of players (i.e. the number of players to reach the 500 club jumped massively from like one every 10-12 years to 6 in 10 years) Until we're an outlier statistically, it's very very hard to make your case for causation or to make any case that there is a significant problem.

       I see your point on the analogy, but lumping all natural causes into one set so you can say that there are only two causes is also misleading. Even grouping all the things man is doing (methane from cows, deforestation, fossil fuels, hydrocarbons etc) doesn't do much to isolate the specific things that are really causing the problem if it even is a problem.

       I find it pretty disingenuous to make the argument that scientists "have something better to do..." seems like a convenient story. There are a lot of scientists writing a lot of peer reviewed papers on climate change and arguing they aren't pointing to humans as the primary cause of global warming is basically making my point. If the scientists aren't explicitly stating that the cause of global warming is primarily man made then the 97% graphic is purposely deceptive. You can't have it both ways. Do people who study lung cancer not point to cigarette smoking as a primary/significant cause?

       I'm going to a choose a random subset of those papers because reading hundreds of papers is more time than I have to commit to this but I find it a little suspect that 97% of all climatologist think we're the main cause or that the current state of affairs is indicative of a major problem. It's my gut feeling that if I choose 20 papers randomly and 3 or more of them don't explicitly state they feel anthropomorphic causes are the main cause of global warming then the 97% number is very suspect, I could do the probability of that happening but even without doing the math I know it's pretty small. I can also figure out what a statistically relvant sample size if I need to but I have a feeling if I read 20 of the papers I'll get very large delta from the 97%.

       Dr Roy Spencer's web page CLEARLY states that he feels the majority of global warming is NOT anthropomorphic. You can read about it here, it's clearly stated in his main navigation...

       Roy Spencer also dispute Gore and his man Hansen that global climate sensitivity is high (which is a big factor in the alarmist nature of the global warming message).

       Pointing to point 1 on that site (that you have apparently not read in any detail) is a red herring. My argument is not that there is no greenhouse effect, my argument is that there is very little evidence to suggest the change in CO2 created in the last 100 years is the significant factor in changes in climate.

       IPCC recently admitted that their earlier claims about the rate of global warming were grossly overstated. (alarmist sensationalism) they also admitted they can not explain the current plateau in temperatures and their models all predicted twice the change than we're experiencing. Basically admitting their models are not strong and their position is flawed all in one fell swoop.

       Additionally Spencer shreds the IPCC for using models that don't find natural causes because they are explicitly designed to search for man made causes. Kind of have to be careful who you're citing as a source for your position when the majority of what your source has to say massively supports my position.

36389. 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.

36390. 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).

36391. 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?

36392. 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?

36393. 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.

36394. 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.

36395. 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).

36396. 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. 

36397. 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. 

36398. 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

36399. 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. 

36400. 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.

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