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Comments 23501 to 23550:

23501. eljoris at 19:11 PM on 24 August 2016
       These are the best arguments from the 3% of climate scientist 'skeptics.' Really.
       

       As a layman, and non native English speaker, I have a question for the well read to which I haven't yet found an answer on this site: The Earth with its magnetic field is a giant electric dynamo floating in the open electric environment of the solar system which is not separated from the electrical environment of the galaxy. Furthermore, the vacuum of space is a plasma filled environment with loose electrons and electric potentials do generate current flows over intergalactic distances. (This is not even controversial.)

       The physical parts of the Dynamo heat up depending on the intensity of this flux, and science does already know that voltage potentials in the sun-earth space vary with time. Wouldn't it be scientifically prudent to atleast send probes out to verify how this variable changes over time at various points in the solar system and outside of the solar system in our small branch of the galaxy? 

       Compared to this large potential for external forcing (pun intended), and various interacting cycles -which might depend on the relative position and movement of our earth within and through this field of electric potentials-, CO2 and for that matter all other earth based variables might just be overqualified and overweighted. 

       Is this potential mechanism actively being researched? I would like to know how climate science has refutiated that hypothesis because it just 'feels' like something you would need a well researched answer to, taking into account various cycles. Do they even keep an open mind to that possibility or just turn a blind eye to it? 

       Kind regards.

23502. MA Rodger at 19:08 PM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       Concerning the bogus nature of the Danley Wolfe graphic introduced into this discussion by Victor Gauer (but on the wrong thread).

       May I introduce my own graphic of three panels that illustrates the bogus nature of Wolfe's analysis, my graphic linked here (usualy 2 clicks to 'download your attachment')

       The top panel reproduces Wolfe's data plot, LOTI (I actually use LOTI as published in May 2014 - what should have been the Wolfe data - it is very close to Wolfe's data and indestinguishable for the data most recent to May 2014) plotted against MLO CO2. Note Wolfe repeatedly says he uses GISTEMP Met Station data but he is obviously wrong. He uses LOTI but adds 14ºC to the values. He calls this "absolute" rather than an anomaly although it is simply the anomaly shifted by 14ºC so not the monthly "absolute" values.

       Added to the Wolfe data is the LOTI data for June 2014-to-date as published today. The annual CO2 cycle (unlike the annual LOTI cycle) remains as per Wolfe's plot. Its inclusion has no physical justification, just as retaining the annual LOTI cycle would have no physical justifictaion. Its inclusion is patently wrong.

       The central panel plots the same data but adds a trace using 12-month averages for MLO CO2 and a red trace that additionally uses the 12-month averages for temperature. As the rate of increase in CO2 has been rising over the decades, the red trace is effectively the LOTI time series but with the early years squished up and the later years stretched out. The ratio of most-squished:most-stretched is about 1:3. So conpared with the more normal time series plot of LOTI, this CO2-series plot will markedly eccentuate any slowdown in the LOTI record during the later years.

       The third panel introduces the trend lines drawn on by Wolfe (the black trace). The flat part of the trend for the later years is not calculated as Wolfe describes. Wolfe's "1998-2014" result can be reproduced (down to the "158 observations") using May 2014 published data and the period 4/2001-5/2014. The other flat trend for the earlier years is undescribed by Wolfe. Importantly, the sloping trend Wolfe shows joining the flat eary section to the flat later section cannot be the result of any analysis. It is probably drawn fancifully simply to connect the top and bottom flat trends. It is entirely bogus.

       The yellow trend is the OLS trend for Wolfe's data through the middle part of the data with the narrower yellow lines extending that trend to the ends of the data. The OLS trend for the entirety of Wolfe's data is represented by the white plot and is very little different from the full-length yellow trend plot. It is thus evidently bogus to attempt to argue that there are any periods either at the start or at the end of this data with significantly lower trends. Yet Wolfe does just that!!!

23503. victorag@verizon.net at 14:19 PM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       #127 P.S.

       Tom, if you go to the SkSc trend calculator, setting the start date to 1960, the end date to 2016, and the moving average to 0 — and select HadCrut4, you'll see a more up-to-date representation that's even closer to your scattergram.

23504. victorag@verizon.net at 13:52 PM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       

       

       (from this site www.walkersands.com/Blog/climate-change-in-the-age-of-google/)

       #127  So, Tom, what you are saying is that the congruence I see between these two graphs is a meaningless optical illusion?

       One other thing. Your correltion of 0.857 covers the entire scattergram, which was not the point. The claim is that three different scattergrams are represented, the first showing little to no correlation, the middle showing significant correlation and the last also showing no significant correlation. That's what I see in both Wolfe's graph and yours. And if there's a problem assigning a statistically derived value to each of these because they're too short, then as I see that's a problem with the statistical methodology, not with our ability to evaluate the data per se.

23505. Eclectic at 13:30 PM on 24 August 2016
       Climate-related disasters raise conflict risk, study says
       

       Haze @5 . More greening [leaf area] in recent decades is evident from the satellite images. This is good for herbivores and livestock. However, higher average temperatures, storms, and heat-waves have a deleterious effect on maize, rice and wheat crops (but especially the maize). Overall crop yields decline . . . and greater extension of croplands is needed.

       Arguably, that produces an environmental degradation - it depends on what definition is used !

23506. Haze at 08:22 AM on 24 August 2016
       Climate-related disasters raise conflict risk, study says
       

       RedBaron@4.  Your comment  "Why would AGW, whose major component is environmental degradation, be any different?"  seems to fly in the face of the many reports noting the increased greening and decreased browning of the planet due to the effects of CO2.  

       For example, Zhu et al note from satellite measurements of leaf area index (LAI)  "a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%).  

23507. michael sweet at 07:14 AM on 24 August 2016
       2016 SkS Weekly Digest #34
       

       At a recent auction of electricity in Chile, an un-subsidized solar farm was the lowest bidder with a bid of 2.72 cents per kilowatt hour.  Joe Romm discusses the auction here.  People who say renewable energy is too expensive will have to explain why coal was almost twice as expensive in this auction.  The Atacama desert has a very high sun resource but they need more long distance transmission lines to bring the power to their cities.   

       Hopefully solar will continue to decrease in price so that buisinesses install solar to save money.  Already, according to Forbes, ""Wal-Mart [is] the single biggest commercial solar generator in the country (United States)."  (in November 2015 they had about 105 megawatts of solar installed.  They save money by installing solar arrays on their roofs.  Other commercial real estate owners are starting to install solar, it is cheaper than the grid.

23508. Tom Curtis at 07:05 AM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       victorag @126, for any scatter plot where the data has a correlation less than 1, and conforms approximately to a linear trend, if you take a small section of the total data measured by distance along the x-axis, the subsection of the data will look like it has a much smaller correlation.  That only indicates that by using a small section of the data you are maximizing the noise to signal ratio.  Because the temperature noise is autocorrelated, the small subsection may give the appearance of a very different trend, but again that is just a product of cherry picking.

       If you want to find a genuine divergence from the scatter plot, you need to find a significant body of data that lies more than two standard deviations from the trend line.  In this case, that means +/- 0.3 C relative to the line 0.0094X - 3.05.  For the demarcated x values, this gives parameters of:

       X value Mean -2 SD +2 SD
       300 -0.23 -0.52 0.06
       320 -0.05 -0.34 0.24
       340 0.14 -0.15 0.43
       360 0.33 0.04 0.62
       380 0.52 0.23 0.81
       400 0.71 0.42 1
       420 0.89 0.6 1.18

       A quick check shows that there are no major clusters of points lying outside the +/- 2 SD limits, and hence no reason to assume a break point in the trend.

       We can take this further by extending the data using that from Law Dome.  Unfortunately when we do so we are limited to annual values generated by a 20 year spline smooth for CO2, and hence annual values for temperature.  That artificially inflates correlation, but not by much given the small variance of CO2 to begin with.  It has no effect on trends.  So, having done so we find the trend is 0.0097 X - 3.13.  The values are within two standard errors of the predicted trend and intercept based on the Mauna Loa data, and are minimally divergent in absolute values.  That indicates the observed trend in the Mauna Loa/Temp scatter plot is robust, and has been in effect since 1850 at least.  Given that, looking to subdivide the Mauna Loa data is clearly not justified (and not justified on two distinct tests).

       There are reasons for a slight visual distinctiveness in the two regions you point out.  Specifically, both the rate of increase in CO2 concentration and in temperature have tended to increase over time.  This results in the points being more densely scattered on the left of the graph than on the right.  This is even more apparent on the Law Dome scatter plot.  As it happens there was an acceleration in the increase in CO2 concentration about when CO2 concentration reached 340 ppmv, which accounts for the denser plot below that level.  Near 400 ppmv the distinctive appearance results from the reduced linear least squared error fit for temperature (ie, not the underlying trend, but the superficial trend) followed by the spike in temperatures starting around 2013.  That reduced superficial trend, however, does not carry the temperature values outside 2 standard deviations of the y estimate, however, and therefore is irrelevant unless it were to continue and carry the values outside that range.  Of course, with the recent spike in temperatures it has patently not done so.

23509. victorag@verizon.net at 05:58 AM on 24 August 2016
       IPCC admits global warming has paused
       

       #9 Tom Curtis

       I responded to your last post, with the new scattergram, on the other thread. To my eyes your result isn't that different from Wolfe's.

23510. victorag@verizon.net at 05:56 AM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       #125 Thanks so much, Tom, for the very thorough explanation, and the corrected scatterplot. Maybe my eyeballs are deceiving me, but I see more or less the same picture as in Wolfe's scatterplot. Random until roughly 340 ppm, correlated until roughly 380, and then random again — with a bit of a spike after 400. What do you see?

23511. Tom Curtis at 05:45 AM on 24 August 2016
       IPCC admits global warming has paused
       

       victorag @6, I quite agree that:

       "Statistical analysis is a vital tool in any climate scientist’s toolbox. However, even the application of sophisticated statistical tools can shed more heat than light, particularly in arguments that focus on limited aspects of statistical significance rather than on broader physical understanding. . ."

       You, however, cannot consistently do so.  First, that is because it means Fyfe et al's acceptance of evidence of a change in forcing leading to a slow down logically precedes their acceptance of the existance of a slow down.  Logically, therefore, it is not an attempt to plug up a theory and make it resistant to contrary observations (as you have elsewhere suggested).  Either the evidence of reduced forcing that justify belief in a slow down is sound (in which case your attempt to impugn it is ill motivated), or it is not (in which case it cannot be relied on to infer the existence of a slowdown, where the statistical evidence is inadequate to justify that inference).

       Further, your argument against the temperature effect of CO2 is entirely statistical.  (Bad, and cherry picked statistics, but statistical never-the-less).  But if you accept the principle above, you cannot rely on entirely statistical arguments in judging the effect of CO2.

       In short, your defence of Fyfe et al based on that quote is, for you, a matter of tactical convenience only as there is no evidence you apply that principle more generally.

23512. victorag@verizon.net at 05:40 AM on 24 August 2016
       IPCC admits global warming has paused
       

       Here's another study, dating from 2014, thus prior to Fyfe et al., in which the "hiatus" is taken seriously — only in this case the authors are unable to account for it: Application of the Singular Spectrum Analysis Technique to Study the Recent Hiatus on the Global Surface Temperature Record

       Some excerpts:

       From the abstract:

       Global surface temperature has been increasing since the beginning of the 20th century but with a highly variable warming rate, and the alternation of rapid warming periods with ‘hiatus’ decades is a constant throughout the series. . . 

       Henceforth, MDV [multidecadal variability] seems to be the main cause of the different hiatus periods shown by the global surface temperature records. However, and contrary to the two previous events, during the current hiatus period, the ST [secular trend] shows a strong fluctuation on the warming rate, with a large acceleration (0.0085°C year−1 to 0.017°C year−1) during 1992–2001 and a sharp deceleration (0.017°C year−1 to 0.003°C year−1) from 2002 onwards. This is the first time in the observational record that the ST shows such variability, so determining the causes and consequences of this change of behavior needs to be addressed by the scientific community.

       From the Discussion section:

       After the maximum warming rate associated with MDV was reached by approximately 1990, ST showed a distinct peak from 1992–2001, with an unprecedented increase of its warming rate from 0.0085°C year−1 to 0.017°C year−1, almost doubling in one decade. After this warming rate peak, the ST shows a pronounced decline, 0.017°C year−1 in 2001 to 0.003°C year−1, in 2013. This type of quick fluctuations in the ST warming rate has no precedent in the observational record (Fig. 3a). . . 

       Therefore, the very recent strong changes observed in the warming rate associated with the ST appear to be a global phenomenon that had not occurred before (at least not during the last 160 years). It could not be attributable to MDV or any other form of climatic variability (such as solar cycles), as the different contributions are effectively separated by the SSA analysis (Fig. 2). This unprecedented modification of the ST behavior should be more deeply studied by the scientific community in order to address whether a change in the global climate sensitivity [21] has recently occurred.

       Here's an article on these findings from the European Commission's website: Last decade's slow-down in global warming enhanced by an unusual climate anomaly

23513. Tom Curtis at 05:37 AM on 24 August 2016
       IPCC admits global warming has paused
       

       victorag @8, I have responded to your comments on CO2 correlation on the original (and appropriate) thread.  In the comment I have shown that:

       Using the data as downloaded (Mauna Loa monthly plus BEST LOTI) increases the correlation fractionally.

       And that Wolfe cherry picks a restricted temperature data set which artificially deflates the correlation. 

       I have also shown a new scatter plot satisfying your stricture that the data as downloaded be used (except for interpolation of missing months).

        

       MA Rodger, regardless of Briggs merits or otherwise, correlation is covariance divided by the product of the standard deviations of the data.  Smoothing reduces the standard deviation, and therefore must increase the correlation.  This was something I was quite aware of which was why my primary analysis used monthly data to obviate any issue of inflating the correlation by smoothing.  As I went out of my way to avoid artificially inflating the correlations, I take exception to Victor's suggestions that my mathematics has been manipulation rather than analysis.

23514. Tom Curtis at 05:28 AM on 24 August 2016
       There's no correlation between CO2 and temperature
       

       victorag has mistakenly posted a response to my post @119 on the incorrect thread.  As the comments are off topic on the other thread, I will reply here.

       Victor wrote:

       "Regarding the difference between "eyeballing" and statistical analysis: there are many ways to manipulate results using statistics, whereas one's eye sees the data directly. Sorry, but where the picture is clearly there for all to see, I'll trust my eye, thank you."

       First, and most obviously, it is as easy to distort with graphs as it is with statistics.  Indeed, in some respects easier.  Second, I find the imputation that my statistical analysis, which I fully described, were designed to manipulate the data, still less to "modfied [the data] to produce the desired result".  For the full Mauna Loa comparison I used the same Mauna Loa data that was used by Danley Wolf, with the sole exception that I used anomaly data because the temperature data was anomaly data, and I wanted to compare like to like, and that I interpolated missing values.  I deliberately used monthly data to avoid artificially smoothing the data.  Over the full interval of Mauna Loa data, had I instead used the raw montly values (with interpolation for missing months), ie, used the data essentially as downloaded, it would have increased the calculated correlation from 0.855 to 0.857, a negligible difference.  That clearly demonstrates that my high calculated correlation was not an artifact of using anomaly data for CO2 concentration.  It should be noted that Mauna Loa, because of its location in the northern hemisphere, experiences a larger seasonal cycle in CO2 concentration than does the global average, so that using the raw data with no seasonal cycle adjustment itself represents an artificial deflation of the correlation.

       "Smoothing creates artificially high correlations between any two smoothed series."

       This is an obvious consequence from the formula for correlation, which is the covarriance divided by the product of the standard deviations.  Smoothing reduces the size of the standard deviation and thereby increases the correlation.  But, just as it is possible to artificially inflate correlations by reducing the standard deviations of the data, so it is possible to artificially deflate increasing the standard deviation (of which more later).

       "Regarding scattergrams: the scattergram offered by Tom lacks sufficient detail to be very useful. Here's another that does, compiled by Danley Wolfe from raw data available to all at:

       Mauna Loa: ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt

       NASA GISS: http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts.txt

       Wolfe does nothing to "massage" his data, it's directly transcribed from the two sites referenced above."

       First, Wolfe did not "directly transcribe" the data.  Specifically, with regard to temperature he added the mean annual temperature durring the baseline period to all values in the mistaken belief that he would thereby convert them from anomaly values.  Anomaly values are calcultated from monthly means, however, so Wolfe's hybrid data represents neither anomaly values or the actual temperatures experienced.

       Second, Wolfe cherry picks his data set.  Instead of using the GISS Land Ocean Temperature Index, he used the GISS Land (Meteorological Stations only) data.  Because that data represents only a third of the globe, and because it largely excludes oceans, the data is far more variable than the GISS LOTI.  Thus by cherry picking the meteorological station data, he takes advantage of the fact that inflating the standard deviation of the data artificially deflates correlations (alluded to above).  This by itself deflates the correlation by about 20%, and the R-squared by about 36%.

       He gains further advantages from his cherry pick.  First, because of the limited geographical area covered by his data, temperature variability is more influenced by local factors, and less influenced by global factors - further decreasing the correlation with CO2.  Second, the meteorological station data is distinctly flater after 1998 than is the Land/Ocean data, thereby further deflating the correlation in the so called hiatus period.  Wolfe is doing well, in that he got three distortions of the data from just one cherry pick.

       In any event, here is a scatterplot of the monthly Mauna Loa data as downloaded except for the interpolation of missing values, against the BEST LOTI.  The correlation as previously noted is 0.857 (R^2: 0.734):

       

23515. victorag@verizon.net at 04:23 AM on 24 August 2016
       IPCC admits global warming has paused
       

       #7 MA Rodger

       If Wolfe's scattergram doesn't suit you, why not produce one that does? But if you do, please use raw data, not data that's been statistically modfied to produce the desired result. 

23516. MA Rodger at 03:53 AM on 24 August 2016
       IPCC admits global warming has paused
       

       Victor Gauer @6.

       I was wondering how long you would take to introduce Danley Wolfe's fabrication into SkS. His MLO CO2 data is as stated but is unadjusted for the annual cycle. And the GISTEMP data isn't as Wolfe states. It is not "NASA GISS global mean (absolute) land temperatures" as Wolfe claims. It is the NASA GISS LOTI anomaly with 14ºC added. (In detail, its origins appear to be a 'collection' of LOTI data. It is certainly not the LOTI data as published in May 2014.) The steep slopey line Wolfe draws on to his graph has no basis other than arbitrarily joining up the two flat unslopey lines, which are themselves not the cherry-picked OLS results that Wolfe claims. When I have a moment I shall illustrate graphically how dreadful this nonsense from Mr Danley Wolfe truly is.

       And after a quick google, Dr William M Briggs appears not to be a good expert to rely on uncritically. Specifically here, what does he mean by "smoothed"? Is it a concern for anything under discussion here?

23517. victorag@verizon.net at 02:35 AM on 24 August 2016
       IPCC admits global warming has paused
       

       #2 Tom Curtis. I'm not qualfied to distinguish between the claims of Werner and Fyfe, but I do find myself agreeing with Fyfe when he comments on the value of a purely statistical analysis:

       Statistical analysis is a vital tool in any climate scientist’s toolbox. However, even the application of sophisticated statistical tools can shed more heat than light, particularly in arguments that focus on limited aspects of statistical significance rather than on broader physical understanding. . . 

       These results illustrate the dangers of relying solely on a statistical test to tell us whether there is, or is not a physically-based change in warming rates.

       Regardless of which view is the correct one, such disputes shed light on the problems faced by climate scientists intent on proving their thesis beyond reasonable doubt. It's all too easy to fall back on the notion that it's now up to skeptics to provide the evidence they themselves have been unable to provide.

23518. victorag@verizon.net at 02:10 AM on 24 August 2016
       IPCC admits global warming has paused
       

       (My apologies again: the links I provided got lost when I re-pasted this post. Please delete post #4. Thank you.)

       For reasons already stated, I will be brief, so as not to waste my time with long explanations that might get edited or deleted. Maybe it's better that way anyhow.

       Regarding the difference between "eyeballing" and statistical analysis: there are many ways to manipulate results using statistics, whereas one's eye sees the data directly. Sorry, but where the picture is clearly there for all to see, I'll trust my eye, thank you.

       Regarding statistical smoothing:

       Smoothing creates artificially high correlations between any two smoothed series. Take two randomly generated sets of numbers, pretend they are time series, and then calculate the correlation between the two. Should be close to 0 because, obviously, there is no relation between the two sets. After all, we made them up.

       But start smoothing those series and then calculate the correlation between the two smoothed series. You will always find that the correlation between the two smoothed series is larger than between the non-smoothed series. Further, the more smoothing, the higher the correlation. (From the blog of Dr. William M. Briggs (PhD in Mathematical Statistics))

       Tom Curtis at #119: Regarding scattergrams: the scattergram offered by Tom lacks sufficient detail to be very useful. Here's another that does, compiled by Danley Wolfe from raw data available to all at:

       Mauna Loa: ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt

       NASA GISS: http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts.txt

       Wolfe does nothing to "massage" his data, it's directly transcribed from the two sites referenced above.

        

23519. Tom Curtis at 23:03 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       MA Rodger @123, given how wrong Victor is regarding CO2 concentration/Temp correlation, I think you are being over generous in your interpretation, unless, and until Victor corrects the record.

23520. MA Rodger at 22:51 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Tom Curtis @122,

       You are entirely correct except that Victor has been so frequently using the phrase "CO2 emissions" down this thread in place of 'increased atmospheric CO2 levels' or 'anthropogenic CO2 forcing' or whatever, that I ignore the true meaning of it and substitute the sensible intended meaning.

23521. Tom Curtis at 22:06 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       MA Rodger @121, Victor's claim that "he evidence I presented concerned the lack of a long-term correlation between global warming and CO2 emissions" assumes a fundamental misrepresentation of climate science.  Specifically, if AGW is correct, we expect a strong correlation between global mean surface temperature and CO2 concentration, but CO2 concentration is not expected to be correlated with CO2 emissions.  Rather, it is a near linear function of cumulative emissions.  Again, there is no necessary correlation between emissions and cumulative emissions.  (There is, no doubt a de facto correlation simply because emissions have grown with time, but there is no reason to suppose it is a particularly strong correlation; and it will be much less than the near perfect correlation with cumulative emissions.)

23522. MA Rodger at 21:35 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Victor Gauer @118,

       Adding to Tom Curtis @119, I am also concerned that your comment @118 is incorrect.

       You tell us:-

       "When we examine the data, as presented in any number of graphs representing global temperature since ca. 1880, we see only one period in which both tempertures and CO2 emissions are rising at roughly the same rate at the same time: the last 20 years or so of the 20th century. Aside from that, no correlation is evident."

       This is an important comment as it is the bedrock of all this palaver running down this comment thread. In this regard, your obsession with CO2 forcings is quite extraordinary and poorly explained. So perhaps the paper Lovejoy (2014)would be of interest to you. The paper sets out some reasons for atmospheric CO2 being used as a proxy both for all AGHGs and for the sum of anthropogenic forcings. Lovejoy (2014) additionally considers the time lags between forcing & ΔT as well as the lack of linearity in the relationship.

       You may find Loyejoy (2014) also interesting because of its Figure 3a, which provides a "graph(s) representing global temperature since ca. 1880" and one which does show significantly more than "20 years or so ... in which both tempertures and CO2 emissions are rising at roughly the same rate at the same time." In truth it demonstrates a convincing correlation over the whole period under analysis 1880-2004, echoing the analysis presented @119.

       

       Of course, you may wish to present your own "evidence" for your absent-but-for-20-years CO2 v GMST correlation. I appreciate that @97 you tell us "The evidence I presented concerned the lack of a long-term correlation between global warming and CO2 emissions. Since I've been told not to repeat myself, I won't get into that again." But you will see up-thread of #97, your presented "evidence" is restricted to almost nothing, indeed absent-but-for-a-bit-of-hand-waving.

23523. MA Rodger at 21:17 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Victor Gauer @116,

       As you truncate your comment for fear thet it will be moderated into oblivion, I have no way of knowing whether your selective response to my comment @116 can be addressed at all. Suffice to say, your repeat waving of the abstract of Fyfe et al (2016) @116 is noted by me and that you should be aware that were Fyfe et al to consider the terms "slowdown" and "hiatus" to be "equivalent," it is mighty odd that for the three times the term "hiatus" is used in that context within the paper, one is saying others use the term "hiatus", a second is within a quote of others who use the term and a third is specifically saying Fyde et al object to use of the term "hiatus". You will note that its use in the well-waved abstract has a description appended just to be sure foolish folk know what they mean by "hiatus" and "global warming slowdown." They make quite clear within the paper that they address a slowdown in surface warming and nothing more. Nowhere do they "specifically refer to the terms "hiatus" and "slowdown" as equivalent" and that includes the abstract.

23524. Tom Curtis at 20:02 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       victorag @118 wants to look at graphs, apparently because he thinks his eyeball can better detect correlations than maths.  For what it is worth, the correlation between CO2 and Temperture from March 1958 to July 2016 (ie, over the full Mauna Loa record) is 0.855 as noted @107 above.  Apparently that fact is refuted (in his opinion) by the superior discriminating ability of his eyeball.  If that is not enough, using  BEST LOTI temperature and the Law Dome CO2 record extended by Cape Grim data, the correlation between CO2 concentration and global mean surface temperature from 1850 to 2013 is 0.903.

       Of course, if you are going to insist on eyeballing your correlations, and not use those lying mathematical methods (/sarc), you can always check out a scatterplot of the values:

       

       When compared to a set of sample scatterplots for different correlations, the similarity to that for a correlation of 0.9 is evident:

       

       Perhaps the mathematics isn't lying at all, and there really is a strong correlation between CO2 concentration and temperature.

       Given this mathematical, and eyeball evidence, I don't know what to make of victorag's claim that:

       "But given the complete lack of long-term correlation in the raw data, it is incumbent on followers of the mainstream view to support the underlying correlation they seek to demonstrate with clear and convincing evidence. Otherwise, skeptics are justified in denying that any such correlation exists."

       Well, no doubt, given that a false statement implies everything.  But both the maths and a simple scatter plot show clearly that there is a high correlation between CO2 and temperature over the last 160 odd years.  

       So the more interesting question is, why given the clear evidence of a long term correlation between CO2 and temperature does Victor persist in insisting that no such correlation exists?  How he does it is easy.  In a mutual plot of concentration and temperature against time, there are periods in which the correlation is not 1.  Indeed, if you do not use smoothed data, there is no period in which the correlation is 1.  Victor appears to take this as proving the correlation is not high, but "does not have perfect correlation" does not imply "does not have high correlation".  Therefore the inference from "does not match the slope in all intervals" to "is not highly correlated" a garbage inference.  

        

       As an aside, Victor also seems to think the ratio of scales of a mutual plot of CO2 concentration and Temperature against time is a given.  How else can we make sense of his claim that "we see only one period in which both tempertures and CO2 emissions are rising at roughly the same rate at the same time: the last 20 years or so of the 20th century".  In fact, the rate of increase of CO2 will be in ppmv per annum, and that of temperature will be in degrees Centigrade (or Kelvin, etc) per annum; so that at no time will they rise at the same rate.  Given that the rates are not commensurate, they can be arbitrarilly varied, and doing so can make any period of approximate linear rise by both graphically coincide.  Victor may be assuming the normal convention of standardizing by the standard deviation of both, but where the short term variability of both is very dissimilar (as is the case for CO2 and temperature), this can lead to deceptive results.  Using the BEST/Law dome data, for example, it leads to a predicted transient response of 1 C per 100 ppmv increase.  On the forcing data derived from the same data set it predicts a Transient Climate Response of 0.59 C/(W/m^2), or 2.2 C per doubling of CO2, which is likely too high.

23525. Tom Curtis at 14:27 PM on 23 August 2016
       Richard Milne separates skepticism from denial
       

       SteveAplin @68:

       1)  A general shift in the Republican party position on climate change has been obervable over the last few decades, from a position indistinguishable from that of the Democrats in the presidency of George H Bush, to a position where the nominee and the runner up of the 2016 presidential race are avowed climate skeptics.  In this context, a shift towards a more "skeptical" position by senior Republicans who has previously backed significant anti-global warming legislation is significant.  Further, a shift in order to win the votes in the primaries (where Republican voters are the dominant part of those appealed to) is more indicative of the Republican party position than any later trimming to not scare away centrist and Democrat leaning voters.

       More importantly, the choice of Rick Perry as an example of the Galileo gambit probably owes most to his being the most prominent and recognisable user of the gambit that was likely to be recognized by students in a Scottish university in 2011.  I will revise that opinion if you can provide me with a list of equally prominent users of the Gambit around 2011.  If you cannot, you need look no further for a reason and your view of the choice of example as being a shot at the Republican party is unjustified.

       2) As it happens, arsenic is present in small quantities in all human diets, and hence in all humans.  We cannot thereby conclude that arsenic is safe.  At higher dosage it is a deadly poison.  Likewise, radiation at low levels in present in all human living environments, as you point out.  At higher levels, it greatly increases the risk of cancer, and at higher levels still it can cause a debilitating disease, or even death.  As it happens, 27 people died from the Chernobyl incident from Acute Radiation Syndrom (ACS).  A further two died from cancer tied to ACS, one died of "external and internal radiation burns, blistered heart", one died of "thermal and radiation burns, trauma", and one of trauma.  I take it that blistering of the heart comes from penetrating radiation, not thermal radiation so that at least thirty of the associated deaths are attributable directly to radiation.  This excludes discussion of any deaths due to the increase of radiation from fallout from the accident, because Milne restricts his discussion to those who were "there when Chernobyl exploded".  From the figures above, if you were present at the power station at the time of the explosion, you were more likely to die of radiation than of trauma or thermal burns.

       Because Milne talks only about the time of the explosion, no inference can be drawn about his views of the relative risk from radiation from fallout which (I agree) are often overstated.

       3)  With regard to Blair, it was possible to tell at the time he was mistaken.  That was because it was known at the time that UNMOVIC, based on on the ground inspections, was clearly stating that Iraq had no weapons of mass destruction in a deployable condition.  That qualification is important because the purported legal justification of the invasion of Iraq was self defence, which required a clear and present danger (ie a danger that could be immediately implimented, and of which you had good reason to think it would be implimented).  It was further known that much of intelligence relied on by the US and Blair was unreliable, with the claims that Iraq was purchasing uranium having been publicly rebutted by the person who investigated the claims.  At the same time, a US intelligence agency was clearly saying the evidence did not support the administrations case, and and Australian intelligence analyst resigned and publicly declared the reason was the distortion of the evidence to make claims supporting the case for war that was not supported by the evidence.

       I paid very carefull attention to all publicly available evidence on this issue at the time; and was outraged (still am outraged) by what I can only see as a deliberate attempt to mistate the quality of the evidence with the intent to decieve the varous electorates of Bush, Blair and Howard (Australia's PM at the time) in order to bring about a war.  At best, it was a case of galloping confirmation bias, but for it to be confirmation bias, the intent to go to war must have preceded the evidence in any event.  Given that many of Bush's senior staff were associated with a conservative think tank that had been advocating a new war with Iraq prior to Bush's election (and ergo, prior to 911) only supports this analysis.

23526. victorag@verizon.net at 14:09 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       #117 When we examine the data, as presented in any number of graphs representing global temperature since ca. 1880, we see only one period in which both tempertures and CO2 emissions are rising at roughly the same rate at the same time: the last 20 years or so of the 20th century. Aside from that, no correlation is evident. That doesn't mean that an underlying correlation might be present that is hidden by other factors. But given the complete lack of long-term correlation in the raw data, it is incumbent on followers of the mainstream view to support the underlying correlation they seek to demonstrate with clear and convincing evidence. Otherwise, skeptics are justified in denying that any such correlation exists. 

       Once again, I won't waste my time elaborating until I feel sure my comments won't be deleted or censored.

       Moderator Response:

       [JH] All commenters on this site are required to abide by the SkS Comments Policy.

23527. KR at 13:38 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       victorag - WRT your links to "The reversed responsibility response", i.e. the reversal of the burden of proof - you have it backwards:

       The correlation of CO2 to warming (as one of many forcings, both natural and anthropogenic) has been well established over the last 150 years, starting with Tyndall, Fourier, and Arrhenius and basic spectroscopy, and continuing through theory, observations, and simple empirical evidence to today. That evidence has been accumulated and collated, the case regarding AGW has been made. The burden of proof now rests upon those who disagree, such as you, to present evidence sufficient to overturn that 150 years of data and theory. Armwaving and nitpicking, let alone semantic gaming and your presentations of short term trends without statistical significance (such as since 1998) do not suffice.

       The strength of that correlation with CO2 was your initial objection to this thread - and quite frankly your objection has not survived examination. Since then you've done little but dance around trying to change the subject. You've been verbose, and your Gish Gallups extensive, but hardly convincing. 

23528. victorag@verizon.net at 12:12 PM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       MARodger: "Victor states @108 that Fyfe el al, by "specifically refer to the terms "hiatus" and "slowdown" as equivalent" but this is untrue."

       See the abstract:

       "It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming, . . " etc.

       As for the rest, I won't be responding further until I am assured that my comments will not be deleted or censored. 

       Moderator Response:

       [JH] All commenters on this site are required to abide by the SkS Comments Policy.

23529. victorag@verizon.net at 11:49 AM on 23 August 2016
       IPCC admits global warming has paused
       

       With regard to Fyfe et al., see the very interesting blog post and discussion at Ed Hawkins' blog. See also the Guest Post by Fyfe et al. on the same blog, followed by many very interesting comments as well.

       I won't comment further until I receive a reassurance that my comments will not be deleted or censored, as I see no point in wasting my time. 

       Moderator Response:

       [JH] All commenters on this site are required to abide by the SkS Comments Policy.

23530. Tom Curtis at 10:50 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       I have responded to victorag @108 on a more appropriate thread.

23531. Tom Curtis at 10:50 AM on 23 August 2016
       IPCC admits global warming has paused
       

       Elsewhere, victorag is arguing that a "pause" exists, basing the argument on Fyfe et al (2016).  He ignores Werner et al (2015) (discussed here).  Werner et al first determine the locations of the break points in the piecewise trends in GMST for a forced number of breakpoints up to eight.  Breakpoints only appear around 1998 or later if you force seven or more breakpoints:

       

       They further apply statistical tests to determine the statistical support for each number of breakpoints, finding the best statistical support for three breakpoints, with potential support for two, four, or five breakpoints.  There is little statistical support for seven or eight breakpoints, and hence little statistical support for a 21st century slowdown:

       

        Fyfe et al (2016) do not include Werner et al in their references, and therefore ignored this evidence.  Further, their rejection of statistical tests showing no change in underlying trend because of their supposedly extended baseline, which is true of the IPCC AR5, but not true of all such statistical tests.  Using their preferred intervals for the "big hiatus" and the "slowdown" and updated NOAA (Karl 2015) data, we can see that the Jan 1972- Dec 2000 interval has a trend of 0.171 +/- 0.061 C/decade.  The Jan 2001- Dec 2014 interval has a trend of 0.078 +/- 0.140 C/decade.  That is, the trend for the second interval includes the trend for the first interval in its uncertainty, and therefore the null hypothesis that the trend has not changed cannot be rejected.  (Note that it can be rejected using HadCRUT4, but that is because HadCRUT4 has limited coverage, particularly in the Arctic and North Africa, as can be checked by looking at the HadCRUT4 Krig data.)  (See also Cahill et al (2015), also ignored by Fyfe et al.)

       In short, Fyfe et al insist on a slowdown because (as they say) their "exploration of an alternative baseline period is motivated by ΔF, the estimate of anthropogenic radiative forcing" rather than because of any statistical evidence of a slowdown.  They have either mistated or ignored the statistical evidence that, based on the temperature series, no slowdown exists (Werner et al), or at least that no slowdown has been demonstrated (statistical uncertainty on the trends of their chosen intervals).

       Worse for victorag is that even if we accept a slowdown in the trends, it was actually predicted by the CMIP5 computer models.  Fyfe et al show the following graph:

       

        The black line is the running fifteen year trend, while the grey shaded area is one standard deviation from the mean of the CMIP5 running fifteen year trend.  The clear dip in the predicted running fifteen year trend is easilly seen.  More importantly, the GISTEMP running fifteen year trend skirts the botton of the 1 SD shaded area, showing that it is easilly within the 2 SD prediction zone.  And if the data is within the prediction range of the model ensemble, the model ensemble is not falsified by the data.  (Further discussion here.)

23532. Bob Loblaw at 10:41 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       In post #106, Victor doubles down on his original list that he claims to support his statement that a "great many skeptics are in fact climate scientists" . In #106, he provides an additional list, this time of simply "climate scientists", and argues that many of those are also not "specifically identified as "climate scientists" per se". He seems to feel that this new list represents the same sort of qualifications as his original list.

       What do the two Wikipedia pages say when you read them? Victor's original list starts with:

       "This is a list of scientists who have made statements that conflict with the scientific consensus on global warming as summarized by the Intergovernmental Panel on Climate Change and endorsed by other scientific bodies.

       whereas the new list starts with:

       "This list of climate scientists contains famous or otherwise notable persons who have contributed to the study of climate science.

       So, Victor's first list doesn't even claim itself that it lists "climate scientists", and his second list only covers "famous or otherwise notable persons who have contributed to climate science". [Note that some of the "skeptic" list names do appear on the second list.]

       No wonder that Victor does not want to argue about who can "truly be regarded as a climate scientist". Again, the two links Victor provides do not say what he is implying they say.

       The new link also has, near its bottom, a link to a List of Authors of Climate Change 2007: The Physical Science Basis. That Wikipedia entry begins with:

       "This is a list of the 620 authors contributing to Climate Change 2007: The Physical Science Basis, which was the 996 page contribution of Working Group I to the IPCC Fourth Assessment Report.

       So, just the IPCC report has 620 authors, compared to Victor's original list of 61 (living) skeptics. I think we can safely say that the IPCC report authors can be considered "climate scientists". I think we could also consider the list of authors contained in the references to that IPCC report to be "climate scientists", too, and the number will be far higher than Victor's list of "a great many skeptics".

       In fact, we could decide to look at the peer-reviewed scientific literature to find out what "climate scientists" are saying about anthropogenic global warming - but we need not, as this has been done (and published). Skeptical Science has several posts describing such studies:

       Consensus on consensus

       Consensus confirmed: over 90% of climate scientists believe we're causing global warming

       The 97% consensus on global warming

       If Victor wishes to argue against the existence of the overwhelming scientific consensus, as described in any of the above posts, then he should continue this discussion on one of those pages. (After reading the posts, of course.) This is increasingly off-topic on this page.

23533. Tom Curtis at 10:32 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       victorag @106&111:

       1)   I excluded the majority of the list of "skeptical" climate scientists as climate scientists not based on their initial discipline, but their singular failure to have written even one peer reviewed paper on climate science, or in a few cases (Rob Carter comes to mind) the fact that their primary discipline and professional activity has been unrelated to climate science and the very few directly related peer reviewed articles they have written have suffered from rooky mistakes.  Regardless even if we accept everybody on the list, you have completely ignored the primary thrust of my comment @104, unless your suggestion that "this post strikes me as extremely literal minded and even a bit pedantic" is a tacit acknowledgement that my explanation of the basics of English is correct, and that my orriginal charge that your claim that "a great many skeptics are climate scientists" is therefore literally false on any interpretation, but that you don't want to admit it.

       2)  Pay attention to the quotation marks.  I quoted what you said.  The second sentence in your quotation is my comment, and you have not responded to it.

       3)  Mathematics is a branch of logic (see Russell and Whitehead, Principia Mathematica, and also the Church-Turing thesis).  It follows from this that all theories stated in mathematical form are theories by the logical definition.  In fact, to not be a theory by the logical definition, a "scientific theory" would have to hold to be false at least some of the logical implications of its axioms/thesis.

       I am beginning to note that indeed the "logic" you use in formal discourse is very different from formal logic.  Formal logic remains, however, the fundamental principle underlying any rigorous proof; and by underlying probability theory, also any statistical "proof".

       4)  I don't see any point in going further on this.  You are insisting that those "disproving at theory" need not provide any evidence for the positive claims they make in that disproof; and nor need they show that the theory they purport to falsify actually predicts the opposite of their purported falsifying index.  Such a claim is nonsense, pure and simple.

23534. victorag@verizon.net at 06:46 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Here's the link to the web page cited above, which got lost when I repasted my comment: The reversed responsibility response

23535. victorag@verizon.net at 06:42 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Please once again excuse me. The formatting got lost when I posted this last time, so I need to fix that and post again. Note to moderator: please remove my post #111.

       #104 Tom Curtis:

       1) See my previous post.

       2)

       "While many skeptics have very obvious biases, if their arguments are sound, their bias can safely be ignored."

       The presumption that their arguments are sound is hardly warranted.

       Where did I say that? I presumed no such thing. IF their arguments are sound, then bias doesn't matter.

       3)

       "". . . logically, the claim that "GMST did not follow the predicted path given AGW" is also a theory." Again: no, not at all."

       Actually, yes. In fact, true by definition of "theory":

       
       You've provided a definition of theory from the realm of formal logic, which is very different from the logic used in ordinary discourse — or scientific discourse either. Look, I'll make it easy for you. Have you ever submitted a paper for peer review? I have. Many times. Have you ever written a peer review? I have. And would you expect someone reviewing a paper that presents a theory to produce a theory of his own if he sees some problem? A theory by any definition of that word?

       You claim that, according to your research, fireflies generate a significant amount of heat, threatening the future of the civilized world. I examine your argument and find a flaw. Fireflies do not generate a significant amount of heat — or any heat at all. Is it necessary then for me to produce an alternative theory explaining why the earth seems to be heating up nonetheless? You tell me.

       4.

       "The passages I quoted are statements regarding basic principles of science that are universally applicable."

       
       I doubt you would get any philosopher of science to agree with that, and you would certainly not get a consensus agreeing with it. For a start we are talking about burden of proof, and "proof" is a very slippery word.

       Yes, if we take this phrase literally you have a point. "Proof" is not expected in science. In math, yes, but not science, because any valid scientific theory can always be disproved or modified over time. So strictly speaking "burden of proof" is a misnomer. But once again as I see it you are being overly literal. What's implied by this phrase is that the one offering a theory has a responsibility to back it up with convincing evidence, while the person critiqueing that theory has no such responsibility and need only find flaws. If for example you offer a math formula to support your theory and I discover an error in that formula, I need not back my observation up with evidence, or a theory of my own, but simply point out the flaw.

       Here's another discussion of essentially the same issue that should help you understand what's at stake: The reversed responsibility response
       Some excerpts:

       When anyone makes a claim that a certain entity or relationship exists, they have the responsibility of supplying supporting evidence. Without such evidence, the claim is worthless. The fact that you know of no falsifying evidence is irrelevant. Those who claim that an entity or relationship does not exist do not need to supply evidence.

       In science, the default position about any relationship is that it does not exist. This position is called the “null hypothesis“. For a claim to be accepted, the proposer must present sufficient real-world evidence for the null hypothesis to be rejected. . .

       Reversing the burden of proof is a form of the argument from ignorance fallacy, in which it is argued that a claim must be taken as true if it hasn’t been shown to be false.

23536. RedBaron at 02:01 AM on 23 August 2016
       Climate-related disasters raise conflict risk, study says
       

       @bozzza,

        One can find many multiple instances of environmental degradation that was an instigator of conficts or war, particularly agricultural degradation and including deforestation, etc.. In fact one could say it is the norm, not the exception. Why would AGW, whose major component is environmental degradation, be any different?

23537. MA Rodger at 00:07 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       Bob Loblaw @99.

       The 'victorag@verison.net' here and the 'victor' @Realclimate are indeed the same Victor Grauer. On top of the unmistakable argumentation, he first appeared as a commenter on both sites in October 2014 with word-for-word identical comments. To quote Victor "There is only one Victor Grauer."

       Moderator Response:

       [JH] Please note that Victor is no on the cusp of relinquishing his privilege of posting comments on this site. He has been cited multiple times for multiple violations (modertion complaint, sloganeering and excessive repetition) of the SkS Comments Policy. Our patience is not infinite.

23538. MA Rodger at 00:05 AM on 23 August 2016
       There's no correlation between CO2 and temperature
       

       I think to get to the nub of this laborious interchange with Victor Gauer there are some fundamentals Victor has failed to provide.

       We have an SkS thread on the topic of why GMST wobbes don't match CO2 wobbles. The OP explains why such a mismatch would be expected under AGW, It provides "the burden of proof" but Victor's position is that this proof is not provided because of apparent "contradictory evidence." As Victor insists @100:-

       "The burden of proof is on the person insisting that the correlation (ΔGSMT v ΔCO2) is real in the face of what looks like contradictory evidence."

       Victor hold great store by such "contradictory evidence", to the point that he suggests there is no difference evidentially in the existance of AGW than there is in existence of leprechauns!!

       There are perhaps two fundamental aspects of Victor's position that remain poorly described. Firstly, while he objects strongly to the OP (& thus the science presented by the IPCC), the size of the gulf between Victor's position & the IPCC's is not truly know. While it appears to be that Victor sees no or very little role for CO2 (along with other AGHGs) as a force in AGW, Victor has failed to set out how much of the science that supports AGW he refutes.

       The second fundamental omission is that Victor has failed to set out the extent of his "contradictory evidence." This I will do here. Victor's initial enquiry up-thread was to find a comprehensive attribution of GMST since 1900. Victor refused to accept any of the studies offered as fitting the bill (studies which included IPCC AR5) and it is the absence of such a comprehensive attribution that was the first piece of Victor's "contradictory evidence" presented here. We have also been treated to a description of the alleged 'dodgy' nature of many of these attribution studies, this presented also as evidence, and to the bold assertion that many climatologists support Victor's "skeptical" stance. Further evidence from Victor comprises two of the wobbles in the GMST record that are not immediately matched by wobbles in CO2 levels. These are firstly the warming prior to 1940 bring too big to be forced by the CO2 of the time, and secondly the post-1998 GMST which is too small.

       If this is the sum of the "contradictory evidence" Victor has to offer, assertions pretty-much debunked already up-thread, there is (with just the one exception) nothing further to discuss.

       That exception is the full paper Fyfe et al (2016) 'Making sense of the early- 2000s warming slowdown' whose abstract Victor has been waving so vigorously recently.

       Victor states @108 that Fyfe el al, by "specifically refer to the terms "hiatus" and "slowdown" as equivalent" but this is untrue. Fyfe et al say that some others refer to the 'slowdown' as a hiatus. Perhaps more tellingly, the paper says "A point of agreement we have with Lewandowsky et al. concerns the unfortunate way in which the recent changes have been framed in terms of GMST having "‘stalled’, ‘stopped’, ‘paused’, or entered a ‘hiatus’"."

       In Victor-speak, the main message presented by Fyfe et al (2015) is that "A warming slowdown is thus clear in observations" but that they make sure to add "it is also clear that it has been a ‘slowdown’, not a ‘stop’."

23539. victorag@verizon.net at 23:02 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       #105 Hi Eclectic. The Fyfe paper can be accessed from here. And yes, I've read it. And yes, they specifically refer to the terms "hiatus" and "slowdown" as equivalent. This is an important and also highly contentious paper that deserves more attention than it seems to be getting in both the media and online forums such as this. 

       Some excerpts:

       The last notable decadal slowdown during the modern era occurred during the big hiatus. [referring to the cooldown from 1940 on] The recent decadal slowdown, on the other hand, is unique in having occurred during a time of strongly increasing anthropogenic radiative forcing of the climate system. This raises interesting science questions: are we living in a world less sensitive to GHG forcing than previously thought, or are negative forcings playing a larger role than expected? . . . 

       Newly identified observational errors [ref. to Karl et al.] do not, however, negate the existence of a real reduction in the surface warming rate in the early twenty-first century relative to the 1970s–1990s. . . 

       In summary, climate models did not (on average) reproduce the observed temperature trend over the early twenty-first century6, in spite of the continued increase in anthropogenic forcing. This mismatch focused attention on a compelling science problem — a problem deserving of scientific scrutiny. Based on our analysis, which relies on physical understanding of the key processes and forcings involved, we find that the rate of warming over the early twenty-first century is slower than that of the previous few decades. This slowdown is evident in time series of GMST and in the global mean temperature of the lower troposphere. The magnitude and statistical significance of observed trends (and the magnitude and significance of their differences relative to model expectations) depends on the start and end dates of the intervals considered23.Research into the nature and causes of the slowdown has triggered improved understanding of observational biases, radiative forcing and internal variability. This has led to widespread recognition that modulation by internal variability is large enough to produce a significantly reduced rate of surface temperature increase for a decade or even more — particularly if internal variability is augmented by the externally driven cooling caused by a succession of volcanic eruptions. The legacy of this new understanding will certainly outlive the recent warming slowdown. This is particularly true in the embryonic field of decadal climate prediction, where the challenge is to simulate how the combined effects of external forcing and internal variability produce the time-evolving regional climate we will experience over the next ten years.

       Tollefson's contention that the paper "does not in any way undermine global warming theory" is accurate in the sense that the authors do not claim that their findings undermine the mainstream global warming view. In fact, like so many others before them, they offer reasons for the slowdown based on the usual invocation of natural forcings, internal variability, etc.:

       This reduction arises through the combined effects of internal decadal variability11–18, volcanic19,23 and solar activity, and decadal changes in anthropogenic aerosol forcing32. The warming slowdown has motivated substantial research into decadal climate variability and uncertainties in key external forcings. As a result, the scientific community is now better able to explain temperature variations such as those experienced during the early twenty-first century33, and perhaps even to make skilful predictions of such fluctuations in the future.

       Regardless of the reasons they suggest for the slowdown, which resemble so many other reasons offered in the past, they provide ample evidence that it is real and that climate scientists need to deal with it rather than simply dismiss it. An unusually candid and honest study, I must say.

       Moderator Response:

       [JH] Your spin on reality as expressed in your final paragraph is absurd. Climate scientists have been rigorously investigating and deliberating about the "slowdown" for over a decade now.  If you pesist in your false and blatant sloganeering, you will forfeit your privilege of posting comments on this site.

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

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23540. chriskoz at 22:57 PM on 22 August 2016
       2016 SkS Weekly Digest #34
       

       Nice plot by Gavin. Very informative. I also like the breakdown of last cycle to land/ocean and hemispheres by Chris Colose:

       https://twitter.com/CColose/status/766321330241306629

       Gavin has also tweeted his R plot of UAH seasonal cycle data:

       https://twitter.com/ClimateOfGavin/status/765911359485779969

       Obviously UAH data starts in 1979 only. But you can clearly see the warming signal on that plot. And, like in GISTEMP set, July 2016 was the absolute warm record in v5.6 UAH set.

23541. Tom Curtis at 22:17 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       victorag @100, I have reserved discussion of this quote to a seperate post because it is directly germain to the topic of the OP (ie, what we are supposed to be discussing in this thread), and because it directly demonstrates the strength of your own bias.  In the discussion, I will refer to certain results regarding the correlation between CO2 concentration and temperature.  I have used the BEST LOTI monthly data for temperature, and the Mauna Loa monthly index converted to an anomaly value for CO2 concentration.  By converting to an anomaly value, I eliminate the seasonal cycle from the CO2 data, just as it is eliminated from the temperature data (also an anomaly).  As a result, I was also able interpolate missing months as the average anomaly of the all months with observed data within three months of the missing value.  This is an effective method with the anomaly data because the seasonal cycle has been eliminated.

       Turning to your position:

       "All that's required is to demonstrate the lack of continuity between the strong upward trend so evident from the late seventies to ca. 1998 and what followed during the following 15 years or so. If the first period appeared to demonstrate a correlation between CO2 and warming, the second period demonstrated the falsity of that assumption. CO2 levels continued to soar while the increase in temperatures slowed considerably. If the relationship is exponential, as has been asserted, then why wouldn't that relationship continue even more convincingly into the 21st century?"

       I take this to be a clear claim that the correlation between temperature and CO2 between Jan 1975 and Dec 1997 is substantially larger than it is between Jan 1998 and July 2016 ("the first period appeared to demonstrate a correlation between CO2 and warming, the second period demonstrated the falsity of that assumption").  I also take it to claim that the correlation between Jan 1975 and July 2016 is less than the correlation between Jan 1975 and Dec 1997 ("why wouldn't that relationship continue even more convincingly into the 21st century?", a quetion that presuposes the relationship has not continued more convincingly).

       As it happens, the correlation between Jan 1975 and Dec 1997 is 0.592, while that between Jan 1998 and July 2016 is 0.507.  It is less, but not substantially less.  More importantly, the correlation between Jan 1975 and July 2016 is 0.832.  That is, the correlation over the full period since Jan 1975 is substantially larger than either of its two subparts, and increased greatly relative to the correlation of the first period even though the correlation of the second subperiod was less.

       In short, your confident assumptions about what the evidence showed with regard to the correlation of CO2 and temperature are simply false.

       There is a reason for that, which should be transparent to anybody truly familiar with AGW theory.  Specifically, the short term temperature response (TCR) to a change in CO2 concentration approximates to 2.17 x ln(CO2/CO2_o) where CO2 is the CO2 concentration, and CO2_o is the original CO2 concentration.  Thus, the expected change in temperature from the average annual increase in CO2 concentration over the period Jan 1981-Dec 2010 was 0.01 C, which is negligible compared to the temperature fluctuations induced by ENSO and volcanic activity.  Therefore, over subdecadal time spans we expect the influence of CO2 to be indistinguishable from the temperature sequence in the absence of any change in the CO2 forcing.  Over a decade, the influence rises to 0.11 C, which is still small relative to ENSO and volcanic fluctuations, but large enough to influence the trend.  Over multiple decades, of course, the ENSO and volcanic fluctuations do not accumulate while the influence of CO2 changes does; so that in the long term the influence of CO2 forcing dominates.  Therefore, as a direct prediction of AGW, we expect correlations between CO2 and temperature to be small over short intervals, but to increase with longer intervals:

       

        Graphed above are the correlations of a running series of intervals approximately 15, 20, 25, and 30 years long.  As can be seen, in general, the longer the interval the higher the correlation, as also the higher the mean correlation and lower the standard deviation of the correlations.  That is exactly what we expect from the theory of AGW, given our knowledge of the small difference in year to year change in CO2 forcing.

       It also gives some idea how the fake "skeptics" have persuaded people that the data from 1998 on "demonstrated the falsity of that assumption".  They show graphs of CO2 vs temperature over just that interval (where due to the short duration, we do not expect a strong correlation) but do not calculate or show the actual correlation values.  They exempt themselves from the burden of proof so that they can employ simple rhetorical tricks rather than cogently discussing the issue.  When you instead look at the change in correlation from the additional years of data, you plainly see the evidence in favour of CO2s substantial influence on temperature has improved.  Or alternatively, when you compare the correlation of the 1998 forwards period with the correlations of past intervals of similar lenght, you see that the correlation is not unusually low for intervals of that length, and therefore not evidence against the theory.

       For what it is worth, the correlation over the full available data is 0.855.

       Further, and obviously, AGW does not consider CO2 to be the only forcing, and not always the dominant forcing so that restricting the discussion to CO2 itself represents a distortion, or at best an oversimplification of the theory.

23542. Jaimesald at 22:13 PM on 22 August 2016
       2016 SkS Weekly Digest #34
       

       The "business as usual" hypothesis is not realistic because business change a lot with time.

23543. victorag@verizon.net at 22:12 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       #104 Tom, I'm sorry, but this post strikes me as extremely literal minded and even a bit pedantic. With respect to the designation "climate scientist," if you look at this list of "climate scientists" you'll see a great many names not specifically identified as "climate scientists." And if you look again at the list I linked to, you'll see that none of these people are specifically identified as "climate scientists" per se. If you take a look at the Wikipedia article for James Hansen, you'll see that he has degrees in physics, mathematics and astronomy — no degree in "climate science." Nowhere in the article is he identified specifically as a "climate scientist" or "climatologist." Obviously he is, but the writer of this article saw no reason to explicitly identify him as such.

       The credentials of most of those in the list I provided include people with backgrounds in fields such as meteorology, physics, astrophysics, earth science, geography, geology, atmospheric science, environmental science, chemistry, etc. We can argue forever as to whether each can "truly" be regarded as a climate scientist or not. I think the point I was making was clear enough, but if you want to insist that this is not a true listing of actual climate scientists I won't argue with you. The larger point is that "climate scientist" vs. "climate skeptic" is not a meaningful opposition. It reflects bias, but clearly you are not willing to recognize your own bias, which is unfortunate.

23544. Eclectic at 21:55 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       Victor @ #97 . . thank you for your reply - but you are wrong once more.

       You referred me to the paper Fyfe, Meehl et al., 2016, in Nature Climate Change ( published online 24th February 2016 ).

       The snippet of abstract you quoted, does not support your contentions.

       The paper is paywalled (and so it was impractical for me to check it in detail) , but I do notice that one of the editors of the journal [Jeff Tollefson] has stated that:

       'Fyfe uses the term "slowdown" rather than "hiatus" and stresses that it does not in any way undermine global warming theory.' [unquote]

       Presumably the editor has read the paper - but Victor, it appears that you have either not read the paper, or have failed to understand it.

       Victor, your argumentation (sic) seems to be a leg-pull, rather than anything scientifically serious.

23545. Tom Curtis at 15:07 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       victorag @100:

       1)  "many" means "a large number of", and "large", like "big" and "small", is always specified relative to the population under consideration.  Thus even while "a large x" is always larger than "a small x", for any given value of x, we cannot infer that a large mouse is larger than a small elephant, and large mountains (such as Everest) fit very comfortably on the surface of small planets (such as Earth).  "Great" is a superlative, that amplifies the meaning of the term qualifed.  Thus "a great many" is a larger quantity than "many".  It follows from this that "a great many leprosy sufferers" will be a much smaller number than "a great many South Americans" and "a great many AGW skeptics" is almost certainly a larger grouping than "all climate scientists"

       If we do not want to take this standard view on the use of the English language, we would have to say that a great many people live in Fordwich,  even though its population is just 0.004% of that of Greater London, and it is "the smallest community by population in Britain with a town council".

       This is just basic English, understood by any native speaker; and understandable by anybody competent in English.  Yet you want to maintain your rhetorical point against these basic facts of grammar, even though to do so you point to a list of scientists (the majority of whom are not climate scientists) whose population is about a sixth that of Fordwich, and which represents and about a 12th of the number of "skeptical" climate scientists I indicated to exist based on statistical data.

       As I said, this is really basic English.  Let us put that aside, however.  Based on statistical evidence, there are about 720 "skeptical" climate scientists from among a population of about 30,000.  That in itself is strong evidence that those 720 odd "skeptical" climate scientists maintain their position because of non-scientific biases (something of which we have independent evidence), and that the consensus position therefore can reasonably be characterized as the position of climate science.

       2)  "While many skeptics have very obvious biases, if their arguments are sound, their bias can safely be ignored."

       The presumption that their arguments are sound is hardly warranted.  Nils Axel-Morner for example (who is on your list) has doctored the photograph of a tree to use as evidence against sea level rise.  This, of course, does not mean that all of their arguments are unsound.  Each must be judged on its own merits, but you are not entitled to assume the soundness of any of their arguments just from their existence as you have done.

       3)   "". . . logically, the claim that "GMST did not follow the predicted path given AGW" is also a theory." Again: no, not at all."

       Actually, yes.  In fact, true by definition of "theory":

       "theory
       A theory T is a set of all sentences in some language K that are implied by T itself [Boolos+Jeffrey1989-cl p.106].
       A theory always contains all valid sentences of K, as these are implied by any set of sentences of K. Thus, for example, every theory contains ∀x (x=x) as this is valid in every language. These sentences can be thought of as the basis of the theory, and that the theory, which by definition is closed under the operation of implication, can be constructed by applying implication successively using the sentences already in the theory.

       Note that in general there are true sentences in K that are not in a particular theory T. In particular, for every theory of any language that includes the language of arithmetic, there are true statements that are not in the theory"

       You may want to insist that there is a distinction between "theories" in logic, and those in science, but given that science accepts logical implication and requires that their theories not be inconsistent, scientific theories are just a subset of logical theories - specifically, that subset of scientific theories whose proof is established by a certain rigorous empirical process.  If, then, that "GMST did not follow the predicted path given AGW" is not also a scientific theory, you need to insist that its truth is not established by scientific empirical methods (in which case it is irrelevant to science).  Alternatively you need to assert a very strong observation sentence/theory distinction, which strong claim has been multiply refuted (see the Duhem Quine Thesis)

       4)  "The passages I quoted are statements regarding basic principles of science that are universally applicable."

       I doubt you would get any philosopher of science to agree with that, and you would certainly not get a consensus agreeing with it.  For a start we are talking about burden of proof, and "proof" is a very slippery word.  Presumably you (and Minhinnick) do not mean logical proof, for if you did not empirical claim can satisfy the burden of proof, and therefore all ontology must be rejected, including the claim that there exists an external world, or indeed any claim that your self exists (unless "self" is taken to mean "a locus of thought").  If we allow it as proof on balance of probabilities, we face similar intractable difficulties because in the end all probabilities are relative, as Popper is at great pains to point out in Logic of Scientific Discovery.  Further, if you mean "provide cogent evidence that" then the assymetry between proof of existence and disproof of existence disappears; and with it any justification for the different burdens of proof.

23546. bozzza at 14:49 PM on 22 August 2016
       State of the Climate 2015: global warming and El Niño sent records tumbling
       

       Australia seems to have had a particularly cold winter that looks to have coincided with not the bottom of the current solar cycle but we are getting toward the bottom of it! It would be interesting to see if next years winter is even colder.

       Saying that there are several factors making the Northern Hemisphere warmer than the Southern Hemisphere. This means the Arctic gets the lions share of Global Warming and if the Arctic sea ice melts the ocean currents will change meaning in ways that are unpredictable and so the earths distribution of heat will change in ways that are unpredictable.

       You would have to guess a lot of people will freeze as there is no longer impetus for the heat from the equator to move toward the pole that has no ice...

23547. bozzza at 14:39 PM on 22 August 2016
       Climate-related disasters raise conflict risk, study says
       

       (..or was that scientific expediency?)

23548. bozzza at 14:38 PM on 22 August 2016
       Climate-related disasters raise conflict risk, study says
       

       I believe the black soil of the Ukraine was wanted by Germany at some point in time for some reason: possibly political expediency?

23549. Tom Dayton at 14:08 PM on 22 August 2016
       There's no correlation between CO2 and temperature
       

       New model by Poppick et al. using human and natural forcings. Amazing fit to observations. In press, but Variable Variability has a preview.

23550. Trevor_S at 11:34 AM on 22 August 2016
       2016 SkS Weekly Digest #34
       

       >Maybe illegible script at its bottom corner would give a clue?

       It's perhaps time for a perscription check ;) It's signed 'Bennett' then says 'christian science monitor' presumably a link to the resource with the same name ?  My take was the same as Bob's above.

       There is also some irony with the juxtaposition of Dr Schmidt's quote 'on business as usual' and the Rio quote... using what precious little emissions budget we have left to have a bunch of people run a round a stadium in Rio, as 'per usual'. Fiddling while Rome burns comes to mind.

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