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Comments 41751 to 41800:

41751. michael sweet at 21:51 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Klapper:

       In post 45 you say:

       "I don't think a negative forcing of 0.1W/m2 over 4 or so years at the end of an analysis period is enough to explain the large errors in the model trends over the last 20 to 30 years compared to observations."

       The Tamino graph in the opening post shows that in 2007 the models were statistically much too low.  Did you complain then that the models should be raised to compensate for their low errors?  Scientists at the time said that it was probably due to natural variation.  More data has shown this to be the most likely explaination.  What is your response to the extreme warming from 1992-2006???  Your claim of 20-30 years is bullshit and should be withdrawn.  Over the past 20-30 years the models have been accurate.  Read the opening post so that you stop making such wild, demonstratably inaccurate claims.

       Moderator Response:

       [JH] Please cease and desist from using the word, "bullshit" in future posts. It is inflamatory and uncivil to do so. 

       This is warning #1.

41752. Rob Painting at 20:27 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Klapper - your reading skills are inadequate. Here's what Solomon et al (2011) state in their study abstract:

       "Recent measurements demonstrate that the “background” stratospheric aerosol layer is persistently variable rather than constant, even in the absence of major volcanic eruptions. Several independent data sets show that stratospheric aerosols have increased in abundance since 2000. Near-global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about –0.1 watt per square meter, reducing the recent global warming that would otherwise have occurred. Observations from earlier periods are limited but suggest an additional negative radiative forcing of about –0.1 watt per square meter from 1960 to 1990. Climate model projections neglecting these changes would continue to overestimate the radiative forcing and global warming in coming decades if these aerosols remain present at current values or increase."

       The Mt Pinatubo eruption was (more or less) a single eruption which substantially lowered global temperature , whereas the changes in moderate volcanic activity shown by Solomon et al are persistent. Sulfate particles can remain in the upper atmospheric circulation for up to two years, but most of them fall back to Earth much sooner than that. Persistent volcanic activity, despite being smaller in intensity, provides an ongoing source of reflective sulfate particles to bounce incoming sunlight back out to space before it can warm the Earth.

       These group of researchers, however, claim this small global dimming trend is the result of moderate tropical volcanic activity, rather than increased sulfate pollution from industrial growth in China & India. This is at odds with other research groups.

       Even leaving aside a potential negative contribution by sulfate particles, there's no way that the models can successfully predict the switch in phase of the wind-driven ocean circulation - which buries heat into the subsurface ocean and therefore temporarily lowers global sea surface and air temperatures. It would be nice if they could.

       Based on these considerations, it's not surprising that the observations are currently below the multi-model mean, but as the figure (above) from the final AR5 draft shows, they are still within the envelope. So the climate models still seem to be doing a reasonable job. The years ahead will be interesting.     

41753. Bob7905 at 20:03 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       First of all I want to make it clear that I am not the Bob who has posted above.  Is it possible for different users to have the same name or have I been hacked?

       Second, I did actually come here to ask a question.  I have seen a couple of comments from 'skeptics' to the effect that, while Tamino may have been technically correct, the corresponding comparisons of models vs observations in earlier ARs used the actual 1990 temperature as a baseline - i.e. had made the same mistake. The implication being that the adjustment in AR5 is moving the goalposts. I'm dubious about this but I don't know my way around the reports and have not been able to find out whether there is any truth in these assertions.

        

       Moderator Response:

       [DB] When users sign up to post comments, they are assigned unique user ID's.  While externally some users may appear to be the same person if a commonly-used user name is selected, internally they are differentiated.  You may wish to change your user name to something more unique.

       Having unique user names is a feature being discussed.

41754. Leto at 17:45 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Stealth@39

       I have no dispute with the text of this post, but I agree that the colour bands of the right-hand graphic in the original post are not particularly clear. I suspected that the graph had been truncated to allow the two graphs to be placed side-by-side, and found a more complete version at Climate Audit:

       climateaudit.files.wordpress.com/2013/09/figure-1-4-final-models-vs-observations.png

       (The CA post has nothing else to commend it, by the way. McIntyre does not seem to understand the need for an appropriate baseline; he does not argue against the new choice of baseline, just skirts around the issue. Search his post for the word 'baseline' and you will not even find it.)

       Dana, could the original post please be modified to include the right-most legend of the draft-final version, where the different projection bands are shown without the confusing overlap?

41755. gpwayne at 15:34 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       I'd just like to add my own view: Nice post Dana...

       That is all...

41756. RogerDty at 15:23 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       bouke @ #4

       While this "anomaly" scaling is a trivial issue, it is a precious gift to those who would muddy the waters. This whole thread is really nothing more than arguing about the global cooling that took place when temperatures moved from fahrenheit to celsius!

       I understand that it makes good sense to report in units of anomaly but it is just adding another layer of complexity to the communication task where you can't buy a thermometer with the "anomaly" scale and minor errors are quickly exploited. 

       I agree its a nice explanation of "Taking the Earth's Temperature" at the American Chemical Society, also Berkeley Earth but some simple examples could well illustrate the process and the arithmetic for primary school level scientists (hopefully already been done?).

       A better explanation of these steps is preferable to "trust us, we're scientists" or other irrelevant appeals to authority or consensus.

41757. Klapper at 13:42 PM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       @ #42 Rob Painting

       From the Solomon et al 2011 paper the negative forcing from volcanic stratospheric aerosols in the period post 2005 is maybe -0.1W/m2 compared to the baseline forcing from stratospheric aerosols. These eruptions had maybe 1/20 the impact of Pinatubo. Pinatubo's effect maybe lasted 3 years, and didn't impede warming much in the period 1975 to 2000.

       I don't think a negative forcing of 0.1W/m2 over 4 or so years at the end of an analysis period is enough to explain the large errors in the model trends over the last 20 to 30 years compared to observations.

       You're arguing the effect of aerosols is much stronger than the modelling demonstrates but I have a hard time believing that since the models already overcool during big volcanic episodes like Pinatubo.

        

        

41758. chriskoz at 11:45 AM on 6 October 2013
       2013 SkS Weekly News Roundup #40B
       

       For those interested in australian politics or who understand their voting system (honestly beyond my grasp, definitely the most complex in the world), a piece of bad news came from the latest senate results:

       The "Palmer United Party" candidate has unexpectedly won the WA senate seat, beating Green party candidate, despite receiveing less votes (9.48% GRN vs 5.0% PUP). Due to some unexplained, whacko "preference distributions" series of steps, a PUP candidate was pushed ahead of GRN. At some step, only 14 votes have decided the outcome. Even with such narrow circomstances, the electoral law does not allow for recount, I imagine to an even bigger frustration of Greens.

       palmer-united-candidate-to-represent-wa-in-senate

       The important and bad aspect (good for climate change denialists) is that the ALP + GRN senators are currently holding the new PM Tony Abbott's "bloody" attempt to "repeal carbon tax". When the new senate takes seats on July 2014, ALP + GRN numbers will dwindle and they may not be able to oppose Abbott's attempt anymore. That extra one seat loss by GRN may tip the ballance of that opposition: a PUP senator is likely to support Abbott. Analysts are now saying Abbott will be able to do the deal with the new senate about cabron tax repeal in July 2014 while previously they've been saying the deal will be hard to achive.

       So, in short, this election event may decide that Australia, so far playing decent role in climate change mitigation, will be going backwards in July 2014. That's the bad news. To those interested how it happened that a party receiving 5.0% of popular vote can beat that of 9.48%, go figure:

       WA senate federal-election-2013

       For me, it's not worth it, as the system should be thrashed in many opinions. Climate science is much much easier and better to spend time on.

41759. Matt Bennett at 11:10 AM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Ok Bob (@26),

       Now that you've been shown Tisdale was completely wrong (yet still being published as a reliable voice by The Australian, a hot-bed of misleading climate drivel if ever I saw one), could you please acknowledge this before posting any further points? And moderators, can you hold him to this?..

       (this is what really gets me about pseudo-skeptics and the nonsense they expound)

       Moderator Response:

       [DB] "And moderators, can you hold him to this?"

       Affirmative.

41760. grindupBaker at 09:47 AM on 6 October 2013
       IPCC model global warming projections have done much better than you think
       

       @sereniac #81 Yes. At least theoretically and trivially simple using plain logic. I don't know the practical odds because my knowledge of ocean circulation is minimal (I just started). If ocean depths absorb a chunk of heat from their upper part then surface temperature is decreased, reducing outgoing radiation to space and therefore "global warming" (the heat coming in) increases. In fact, that's almost what Balmaseda, Trenberth & Hallen ORAS4 reanalysis claims has happened ~10 years past, a significant increase in "global warming" due to surface temperature  rise being reduced while the atmospheric conditions that "trap heat" pertain and even increase. Converse would pertain, if El Ninos were to boost surface temperatures then this would slow or stop "global warming" as you suggest. In general, provided that atmospheric conditions for "global warming" or "global cooling" remain essentially unchanged (aerosols, volcanoes and so having no big change) then any surface temperature sudden increase has reduced or stopped "global warming" and a sudden (in terms of the topic, just a few years) drop in surface temperature must imply an increase in "global warming".   

41761. grindupBaker at 09:28 AM on 6 October 2013
       IPCC model global warming projections have done much better than you think
       

       @sereniac #102 " climate models...smaller geographic grids" is discussed in one or more of some University of California Television climate modelling lectures by Prof Inez Fung inc. "Anatomy of a Climate Model: How Robust are Climate Projections?" per my #77. Good stuff. I've not had time yet to finish listening. 15-minute time slice used in climate simulation "model" (I used 0.1 second time slice in my elevator simulation Java software I wrote but don't need that fine dicing for climate). Was 1 degree latitude/longtitude grid but Prof Fung tells what it is now & vertical digitizing & hence total box count for the ecosystem simulation "model".

41762. Jim Eager at 04:20 AM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Bob @ 26, Tamino shreds Tisdale's underlying assumption here tamino.wordpress.com/2013/10/05/bob-tisdale-pisses-on-leg-claims-its-raining/

41763. Rob Painting at 04:17 AM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Klapper - there is large uncertainty over the negative forcing by aerosols. Indeed, there is evidence that the observations imply a stronger negative forcing than that adopted in the CMIP5 simulations - see Shindell (2013). Other researchers may disagree, however that merely underlines how uncertain the negative aerosol forcing is. 

       And your comment about Pinatubo is misplaced. SkS has frequently mentioned research indicating an increase in emissions from moderate tropical volcanic activity through the 21st century - Solomon (2011), Vernier (2012).

41764. r.pauli at 03:03 AM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       "Men argue, nature acts"  Voltaire

41765. Klapper at 01:27 AM on 6 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       @ #37 Rob Painting:

       The CMIP5 models use actual inputs up until 2005 as far as I know.These model experiments only started 2009 so the RCP runs had no reason not to use actual data up until 2005. There have not been any major volcanoes since Pinatubo so I don't think that is a relevant issue to the "hiatus".

       Steve McIntyre graphed some CMIP5 model trends of SAT from 1979 to 2013 with a box plot (against the HadCRUT4 trend over the same period). Considering the lower bound error bar on the box with all model runs (109 in all) barely overlaps the HadCRUT4 trend, it seems the models are biased warm and this is over a period where the main warming took place and the models are using mostly actual inputs for aerosols and CO2.

41766. Jim Hunt at 01:22 AM on 6 October 2013
       Latest myth from the Mail on Sunday on Arctic ice
       

       The Mail on Sunday's erroneous Arctic sea ice headlines were repeated by The Sunday Telegraph, amongst numerous others. We have now extracted a similarly grudging "correction" from The Telegraph too:

       http://GreatWhiteCon.info/2013/10/will-the-telegraph-print-the-truth-in-the-cold-light-of-day/

       However we are far from satisified with the responses we have elicited thus far. Watch this space!

41767. StealthAircraftSoftwareModeler at 21:11 PM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       In the comparison of the draft version (the left chart) and the final version (the right chart), why did the IPCC change the scale of the chart? The dates along the X axis on the left chart range from ~1990 to 2015, or a span of 25 years; the dates on the right chart range from ~1950 to 2035, or a span of 85 years. The temperature scale on the Y axis on the left chart spans 1.6 deg C; on the right it spans 2.5 deg C. The really interesting part of the information that would show recent model accuracy in the final version is only 1/5th the area of the draft chart, making it much harder to examine ((1.6/2.5)*(25/85)=.188, which about 20%, which is 1/5th). Most of the final IPCC chart is uninformative empty white space. Furthermore, what does the spaghetti add to the information? It doesn’t appear to add much, but it certainly clutters up the chart, making it nearly impossible to see the actual temperature plot. The simple banded range of model projections in the draft image make it easier read the chart. Can some here redraw the IPCC final chart clearer, properly baselined, without the spaghetti lines, and zoomed in around the last 25 years (i.e., about the scale of the draft chart)?

       Moderator Response:

       [DB] Try reading the OP again.

41768. Rob Painting at 20:37 PM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       KR - although only a short period of observation, the ARGO network does show that heat is stored in the subsurface ocean during La Nina, and rises to the surface during El Nino - hence the effects on global surface air temperatures. Image from Roemmich & Gilson (2011) - The Global Ocean Imprint of ENSO.

       

41769. Rob Painting at 20:26 PM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Klapper - there is no reason why observed temperatures - equivalent to one climate model run - should match the multi-model mean. Climate models cannot predict tropical volcanic eruptions, the wholesale shift of global manufacturing to China, and any effects it may have had on sulfate burden in the atmosphere, nor changes in the phase of the wind-driven ocean circulation.

       There may be something amiss, only a handful of the climate models accurately simulate the changes in winds which alter the wind-driven ocean circulation for instance, but it's bit early to make that call. The observed temperatures are still within the envelope and may move upwards sharply with a shift in the ocean oscillation. Time will tell.

41770. sereniac at 19:56 PM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       I have used multiple regression in the past (mostly on census data- which is inherently noisy) and something that is very apparent is how the degree of data aggregation can dramatically inflate correlations and subsequent R squared values. For example if data is at household level and is aggregated upward to say local council or even higher to city or state level, correlations steadily increase as the natural variability is removed.

       When I saw the R squared values associated with climate models- in the order of 0.97 or so, I nearly fell off my chair. Obviously physical systems have less instrument error associated with their measurement but even so I wondered to what level data aggregation is done in climate models (I originally thought the opposite was happening i.e. smaller and smaller geographic grids were being applied) and whether it is potentially problematic in these analyses.

        

       Thanks again

41771. OPatrick at 18:24 PM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       sereniac @81 - I'm genuinely curious - when you asked the question

       In other words, if the climate has large scale regulatory properties, of which ENSO

       looks be one and it is inherently unpredictable, then could it (or other processes)

       kick in to dampen the warming trend at some point.

       was there a reason why you didn't say "... to dampen or increase the warming trend ..."? 

41772. Klapper at 17:47 PM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       I downloaded the CMIP5 model ensemble mean for the RCP4.5 scenario and checked the projected warming rate 1990 to 2013 to compare with your graph above of projection warming since 1990. The warming rate of the model mean is 0.29C/decade over the 24 years the trend was calculated. That's pretty much double the actual SAT warming rate.

       You might be right the observations are still "within the error bars" but it seems pretty clear the models are running too hot.

41773. KR at 13:08 PM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       sereniac - Regarding your question on ocean data, I believe (IMO) that the observational uncertainties in OHC make it difficult to clearly examine ENSO changes. While I'm sure there are papers out on that topic, I don't know of any off hand. OHC is usually reported in five year running means as a result. 

       However, many of the global circulation models (GCMs) with sufficiently detailed ocean dynamics do produce ENSO style variations, with the rate of heat transfer to/from the deep ocean changing surface atmospheric temperatures. A recent paper by Kosaka and Xie (discussed on SkS here) ties model ENSO style variations to recorded ENSO indexes, and finds that the model accurately matches observed temperatures including the recent 'hiatus'. That is driven by a period starting with a large El Nino (1998) and ending with several La Ninas. So yes, these variations are incorporated in the models. In fact, they emerge from detailed physics - they are not 'programmed in'. 

       Note that the ENSO is probably best described as an aperiodic variation, somewhat chaotic and quite sensitive to starting values - which is why different models and different starting conditions will result (unless otherwise constrained) in a variety of modelled ENSO patterns. 

41774. KR at 12:53 PM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Extending a bit on the leaked and draft figure, the uncertainty bands are actually rather interesting. The caption for that figure states "The 90% uncertainty estimate due to observational uncertainty and internal variability based on the HadCRUT4 temperature data for 1951-1980 is depicted by the grey shading." 

       Most depictions of the variability, such as the yearly updates at RealClimate, display a 95% range of the model results. This figure instead shows the projected trend ranges +/- variation of observations, and should in fact be a more accurate range. Models vary considerably in how well they deal with internal variability (ENSO and weather, for example), but the observations themselves should encompass all sources of variation from the trends. And, with or without proper baselining, observations fall well within that envelope. 

       While not the most common depiction of potential variations around the energy bounded trends of climate change, I would (personally) consider it a very useful view to consider. 

41775. KR at 12:44 PM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       sereniac - There is an excellent and very simple analysis by John Nielsen-Gammon, expanded upon here, on this very subject, which was discussed on SkS as well. He classified years as El Nino, La Nina, or neutral, lagging those classifications by a few months for the variations to take effect (as supported by Foster and Rahmstorf 2011), and found the following:

       

       GISTemp global temperatures, with trends for El Niño, neutral, and La Niña years computed separately. Pinatubo years are excluded.

       He notes that "The spacing between the lines is a good measure of the impact of El Niño and La Niña. All else being equal, an El Niño year will average about 0.2 C warmer globally than a La Niña year. Each new La Niña year will be about as warm as an El Niño year 13 years prior."  (Emphasis added)

       The trends of all three categories are all about 0.14-0.16 C/decade, depending on how you assign ENSO years, with variations superimposed on an underlying warming trend. 

41776. Tom Curtis at 11:35 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Out of interest, here is the procedure for making figure 1.5 from the second order draft (I do not include the discussion of the uncertainty band):

       "AR4: The data used was obtained from Figure 10.26 in Chapter 10 of AR4 (provided by Malte Meinshausen). Annual means are used. The upper bound is given by the A1T scenario, the lower bound by the A1B scenario.

       Observations 

       The observations are shown as annual means relative to 1961-1990. No smoothing is applied. Whiskers give the 90% uncertainty range of the Morice et al. (2012) dataset. These include the combined effects of all the uncertainties (measurement and sampling, bias and coverage uncertainties).
       
       Projections

       The projections have been aligned to match the mean observed value (averaged over the three observational data sets) for year 1990."

       And here is the equivalent discussion from the draft report:

       "AR4: The temperature projections of the AR4 are presented for three SRES scenarios: B1, A1B and A2.  Annual mean anomalies relative to 1961–1990 of the individual CMIP3 ensemble simulations (as used in AR4 SPM Figure SPM5) are shown. One outlier has been eliminated based on the advice of the model developers because of the model drift that leads to an unrealistic temperature evolution. As assessed by Meehl et al. (2007), the likely-range for the temperature change is given by the ensemble mean temperature change +60% and –40% of the ensemble mean temperature change. Note that in the AR4 the uncertainty range was explicitly estimated for the end of the 21st century results. Here, it is shown for 2035. The time dependence of this range has been assessed in Knutti et al. (2008). The relative uncertainty is approximately  constant over time in all estimates from different sources, except for the very early decades when natural variability is being considered (see Figure 3 in Knutti et al., 2008).

       
       Data Processing

       Observations

       The observations are shown from 1950 to 2012 as annual mean anomaly relative to 1961–1990 (squares).  For smoothing, first, the trend of each of the observational datasets was calculated by locally weighted scatter plot smoothing (Cleveland, 1979; f=1/3). Then, the 11-year running means of the residuals were determined with reflected ends for the last 5 years. Finally, the trend was added back to the 11-year running means of the residuals.

       
       Projections
       For FAR, SAR and TAR, the projections have been harmonized to match the average of the three smoothed observational datasets at 1990."

       As can be seen:

       1)  In both figures observational data is baselined to a common 1961-1990 mean.  The difference between them lies in the addition of the smoothed observational data sets in the final (Draft) version.

       2)  In both figures, projections from the First, Second and Third Assessment Reports are baselined to the single year of 1990.  The difference lies that in the final (Draft) version, they are baselined to the mean of the smoothed observational data sets in 1990 rather than the mean of the 1990 values.  This has the effect of raising the projections with respect to observations by 0.13 C.

       3)  AR4 projections are treated entirely differently between the two versions.  In the 2nd Order Draft, they are treated in the same way as the projections from the other assessment reports.  In the final (Draft) version, the individual model runs are shown, all baselined to the 1961-1990 period.

       It is important to note that in the earlier version, and the final (Draft) version, observations and models (other than AR4 in the final version) are baselined differently - something Dana did not pick up in the article above.

       Turning from what was done to whether it was appropriate, I first note that in the final (Draft) version, AR4 model runs and observations are all baselined on the same period, where that period is not the period we are comparing.  That means it represents a perfectly valid comparison.  That the baselining period (1961-1990) is different to that actually used in AR4 (1980-1999 according to Lucia) is of little consequence.  The effect of the earlier baselining is to allow a slightly greater spread in the models, which is matched by allowing a slightly greater divergence between models and observations.  Using the later baseline period would have (conversely) both reduced the spread and the divergence.  The net effect of the choice should be negligible.

       Second, the baselining of model mean projections on the smoothed observational data in a single year is also appropriate.  Because short term variations (other than from volcanism) do not appear at the same time in model runs, model means are smoothed data.  Consequently the final (Draft) method for comparisons with the First through Third Assessement Reports is also appropriate.  (It should be remembered that none of the three earlier Assessment Reports included historical forcings after 1990.)

       Finally, as Lucia agrees, baselining the model data against a single unsmoothed years data, as done in the Second Order Draft version is inappropriate.  Unless you are very fortunate, it will introduce artifacts into the comparison, and in this case tended to show the observations as falling further behind the projections than was actually the case. 

41777. sereniac at 11:19 AM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       KR #95 indicated:

       "A La Nina, with higher wind-driven exchange of deep cooler water, moves a greater portion of that incoming solar energy into the oceans, cooling the atmosphere by ~0.1 C. An El Nino reduces the deep circulation, reducing energy flow into the oceans, causing that energy to remain in the atmosphere and warm it by ~0.1 C. It's really that simple."

       Does the ocean data support these changes in energy distribution/location resulting from ENSO variation and when these data are incorporated into models does their output still support the warming trend?

       I suspect this will lead to a link somewhere- which would be welcomed.

       Thank you

41778. sereniac at 11:12 AM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       I find this fascinating.

       I'm hoping that I'm asking semi-intelligent questions that other forum readers will find beneficial, however if this is too basic, or covered elsewhere then please tell me to depart and I will happily comply.

       I completely agree with KR that extended analogies quickly lose their fidelity and can be dangerous if projected backward onto the system itself as well as extended beyond their foundation. The two slit experiment has clearly shown the conceptual limits of regarding say an electron as just a localised chunk of matter like a ping pong ball.

       Glenn Tamblyn's final point:

       "Mr Jones' glucose problems become apparent when he can't engage in his training for the fun run because he is hobbling along with a cane."

       This raises the question about how long Mr Jones' cane hobbling can be delayed if there is a long series  of intense training for fun runs. i.e. how long can the warming signature be obscured by a long series of intense la nina.

       I think Mark R #81suggested that this might be of the order of 1-2 decades should a kind of permanent la nina cut in.

       My "belief" is that this would be very difficult for most people to accept which is why I constructed the analogy as a lay explanation to show how long term trends can be masked by factors that are periodic but still unpredictable in intensity and duration.

       This is a major issue for the perception of AGW I think because many people have great difficulty reconciling the assurance that climate systems are predictable even when major components of it are not.

       I hope this is not too off-topic and political.

       Thank you

41779. Rob Honeycutt at 11:03 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       In other words, Bob, you can't just post a comment from Lucia.  She can come here and make the comment herself if she likes.  If you want to have your comment not moderated you need to provide your own substantive points.

41780. Tom Curtis at 10:45 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       The comments policy states:

       "No link or picture only. Any link or picture should be accompanied by text summarizing both the content of the link or picture, and showing how it is relevant to the topic of discussion. Failure to do both of these things will result in the comment being considered off topic."

       (My underlining)

       My understanding is that the purpose of this section of the comments policy is to ensure posters actually engage in the discussion by showing the relevance of their linked material to the discussion.  If they do not so engage, readers are left to guess as to whether the link is in fact worth following; and if followed, what part (if any) of the linked material is relevant to the discussion on SkS.

       IMO, Bob does not follow the letter of this requirement, and blatantly fails to follow the spirit.

41781. Leto at 08:49 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Re: OPatrick @19, quoting the draft report:

       "Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years."

       You said: " the replacement wording is not different enough to justify her criticisms."

       I think we are in broad agreement, but I would go further... It was appropriate to remove the bolded statement, because it was ambiguous, propping up a contrarian talking point that should not be an issue in the first place. Ensemble means do not reproduce the recent "hiatus" (and are not expected to), whereas as individual model runs do reproduce a pattern of randomly distributed hiatus decades (some individual runs would even - by chance - roughly put the "pause" in the historically correct place). The distinction is not well covered in the removed statement.

       Curry should know this. She is engaged in a disinformation exercise, not science.

41782. Bob Loblaw at 07:56 AM on 5 October 2013
       CO2 is just a trace gas
       

       Tom:

       My definition is the essential of the old reasoning that led to the (poorly-chosen) name "greenhouse effect". The idea was that the glass of a greenhouse let in visible light and block IR going back out. There is the old "re-radiation" line of thought that builds into that as well. So, like a greenhouse, the atmosphere lets in visible light and blocks IR.

       Now, it turn out that greenhouses are not warm because of the blocking of IR - plastic ones transparent to IR work just as well - but rather due to the greenhouse confining heat close to the surface by reducing turbulent mixing of the air. So, the radiative effect of the atmosphere isn't at all like a greenhouse. [And I know you know that.]

       But then, it turns out, thinking solely about the radiative effects of the atmosphere also doesn't really explain it all, either. If radiation were the only way of moving energy around, the atmospheric temperature profile would be a lot different from what it is - with a much warmer surface. But the atmosphere is mixed, and much energy is carried from the surface to the upper atmosphere by thermal mixing and by evaporation (at the surface) and condensation (at height). [And I know you know that, too.]

       So, neither the greenhouse, nor the atmosphere, are explained by soley the IR radiation characteristics.

       I disagree that a definition of "greenhouse effect" that only looks at IR radiation is "best". If the atmosphere was opaque to visible light, then the top of the atmosphere would be hottest, and IR wouldn't matter much at all. After all, look at the stratosphere: just the extra absorption of energy in the UV range is enough to reverse the temperature profile. The fact that much of the energy from the sun reaches the earth's surface is an essential part of the process.

       Until I try to access a copy through work, I'll have to settle for the abstract of the paper you reference. Although I understand the need to correct distortions of the radiative effects of various constituents that are presented, the paper does just appear to focus on the IR radiation portion of the issue. That's enough to show the bogosity of "it's all water vapour" crowd, but it's still an incomplete picture.

41783. funglestrumpet at 07:10 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       Jose_X @ 17, 18 & 19 Thanks for taking so much trouble and effort to answer the question I didn't ask, but should have. Now I understand it better, thanks to you, I rather think I might have won a few discussions in the past rather unfairly! Still, all's fair in love and war, isn't it?!

41784. Jose_X at 07:00 AM on 5 October 2013
       IPCC model global warming projections have done much better than you think
       

       To summarize an important point Leto made on the analogy:
       
       The temperature of an el nino year is like finding the weight of a person right after they put a large meal into their stomach.
       
       The temperature of a la nina year is like finding the weight of the person right before they eat.
       
       It should be clear that a person who is gaining weight steadily (consuming higher calories than they expend) will still likely have a lower weight tomorrow right before their large meal than they will today right after their large meal. So while their weight trend is going up, it doesn't go up in a straight line. It oscillates as they consume a meal and later burn some of it off before the next meal is due. Because the net weight gain per day is relatively small compared to the weight of each meal, the main difference on whether they weight more or less tomorrow is based on when the weight measurement is taken relative to their meals.

41785. Jose_X at 06:47 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       funglestrumpet @14, here is the summary:
       
       We can roughly liken CO2 going into and out of the atmosphere using 3 analogies.
       
       1 -- We don't care about how long it takes for extra man-made air put into a ballon, or water put into a tank, or food put into a body, to exit.
       
       2 -- We care instead about how long it will take to return to normal volume once we stop adding the man-made air, water, or food.
       
       The argument described in this article crudely measures how long it takes a man-made molecule of air, water, or food, to exit, but that doesn't address what we care about: how long it takes for these systems to return to the normal levels after we stop adding the man-made air, water, or food. I don't care about the speed of travel in my body of my daily cheesecake (from entry to exit). I care about how long before I lose the weight I put on because of that cheesecake.

41786. Jose_X at 06:38 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       funglestrumpet @14, here is take two (using two different analogies than the earlier air in balloon analogy, water in tank and food in body).
       
       The argument in this article (even if using a too crude model) is about how long it takes for a molecule of "man-made" CO2 to come into the atmosphere and leave.
       
       Is that what you care about? If I have a large tank to which I am adding water but from which some water is leaving, do you want to know how long before the water molecule I add leaves at the bottom? Do you care if the addition is slow and the escape is slow so that the transit time is 1000000 years? Would it make a difference to you if instead the addition and escape were super fast and took 1 second?
       
       I think the primary question (the question as goes global warming) is how fast that tank is being filled *after* we take into account the result of both the additions and the subtractions.
       
       Do you want to know how fast it takes for the food you eat to exit OR do you want to know how much weight you are putting on after taking into account how much you eat and what leaves the body?
       
       The latter is what is important. The argument above tries to make a claim about the latter based on (a crude) analysis of the former without taking into account net gains or losses.
       
       If you care about the latter, then the answer you want is how long it would take for the CO2 to return to "normal" (ie, to some base reference level after factoring out natural factors that may change that reference level over time) after we remove the "man-made" components. Ie, you want to know how long before I return to my "normal" weight after I stop eating that extra dessert after every meal. How long it takes for the food to pass through your body (very fast or very slow) is irrelevant.

41787. dana1981 at 06:36 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Ugh, well I just wated 5 minutes of my life reading Tisdale's post.  If Tisdale ever actually says anything intelligent, then let me know.  Until then I prefer not to waste my time reading his drivel.

41788. Jose_X at 06:21 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       funglestrumpet @14:
       
       Man is adding CO2 and some of that is leaking back out. This we all seem to agree on. But..
       
       The argument described at the top is a simplified model. Too simplified. It assumes that the atmosphere is a pipeline. It obviously is not. While an engine might have most of the air coming in at one location then move to exit elsewhere, perhaps crudely approximated as a single file queue, the atmosphere has lots of CO2 rise high to areas where there are few sinks. There is no physics that I know that suggests a model of a queue applies. The CO2 is *not* following a path single file that takes it way up high and then spins and comes down to leave at the ground level. That 5 year figure is the result of a simplified queue model. You can forget about it unless perhaps you want to believe the man-made CO2 entering and leaving the atmosphere is doing so in as a queue.
       
       Another analogy is the difference between fast moving draft air in a narrow cooridoor that is open at each end. This is like a queue. The atmosphere instead is like a huge balloon with two openings near each other, where one opening slowly adds air and the other slowly removes it. In this balloon example, we have nothing resembling a queue.
       
       Besides that the flow is not like a queue IMO, you are asking a different question than what is presented above. The five year is supposed to be the average time for CO2 to move into the atmosphere and back out, but the question you are asking is how long before we return to the same quantity of CO2 we had if we stop adding CO2. You care about how long before the air in the balloon gets back to the same quantity if we remove one of the several drivers adding air into the balloon.
       
       If we stop adding, there will be a net loss of CO2 that will slowly work its way back towards a more natural condition. It will take many years to make it most of the way there, but like an exponetial decay curve (if that model were to resemble the effect) we would never really get back all the way. Of course, the earth is more complex. If we plant and manually sustain more trees (or add other CO2 sinks.. eg, consume CO2 via microorganisms that sequester the result in some chemical form), then we could not only get back to "normal" as defined by today's system but even go beyond it. And then there are planetary effects and basically a bunch of effects (feedbacks) that don't follow the exponential decay model either.
       
       Sorry to not give you a precise answer. You asked in the right place and some studies address that concern. I just wanted to give an idea that what you are asking has nothing to do with this abstract 5 year calculation.
       
       

41789. funglestrumpet at 06:21 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       MA Rodger @ 15

       Thanks, that is exactly what I was looking for!

41790. MA Rodger at 05:39 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       funglestrumpet @14.

       Archer 2005 concludes with the following line that may be what you are looking for. (I have edited a little it to make its meaning clearer.)

       
       A better approximation of the lifetime of fossil fuel CO2 for public discussion might be ‘‘300 years, except for 25% of the CO2 that lasts forever."

        

41791. funglestrumpet at 04:59 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       HELP!!! Could someone please help a poor confused bloke like me who comes here to help them do battle at the street level on the climate change front (think Daily Mail readers and the like)?

       For instance, when 'debating' with a typical denier on the "global warming has stopped" meme, I have tended to use the argument that it takes ages (plus or minus an age or two) for CO2 to fall out of the atmosphere (and sod what Newton might have to say on the topic because apples are a lot heavier than CO2 molecules and thus fall more readily).

       It follows that global warming cannot have stopped because the excess CO2 we have pumped into the atmosphere over that last half century or so is still airborne and will be there for a long time yet warming the planet as it does so. Five years is not even near half an age, so what number of years should I use in presenting my case, 5, 50, 75 or what?

       I imagine the answer lies in the article somewhere, but it is well hidden from a simpleton like me.

41792. william5331 at 04:35 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       There is a grain of hope, losely related to Prof. Essenhigh's contentions.  Carbon dioxide varies about 7ppm annually or more accurately, 8 up and 6 down.  Natural processes remove far more CO₂ than any silly system we could devise to sequester Carbon dioxide.  Of course we must first stop pouring Carbon dioxide into the atmosphere but then we could give Gaia a chance and restore her systems for removing CO₂ to their full potential.

       http://mtkass.blogspot.co.nz/2013/03/removing-atmospheric-carbon-dioxide.html

41793. raywey at 04:23 AM on 5 October 2013
       Residence Time and Prof Essenhigh
       

       A useful analogy (and a bit closer to the actual situation than the queue) especially here in Caifornia where lots of people have spas and swimming pools:

       My pump circulates water into and out of my spa at an input rate of **** (fill in your
        favorite number) and removes it at the same rate. But I have taken my garden whose
        and added water at a much smaller rate (&&&&). The residence time for any molecule of water in the spa is short compared to the time the hose fills an empty spa, but does anyone think that it is not the hose that is causing the water level in the spa to increase?

41794. Composer99 at 04:04 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       If that's what Tisdale comes up with as an "only imaginable reason", then I submit that he is admitting to having a very stunted imagination.

       Which would be selling himself short: like most "pro/semi-pro" contrarians/deniers, Tisdale actually has a very fertile imagination. (Unfortunately, he has the bad habit of mistaking (or misrepresenting) the fruits thereof for reality.)

41795. Rob Honeycutt at 03:55 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Let's look at Tisdales opening complaint where he states, 

       The models presented from the IPCC’s 1st, 2nd and 3rd Assessment Reports are considered obsolete, so the only imaginable reason the IPCC included them was to complicate the graph, redirecting the eye from the fact that the CMIP3/AR4 models performed poorly.

       Really?  The only imaginable reason?  Do you start to wonder why Lewandowski is publishing on conspiracy ideation amoung climate denialists?

       So, Tisdale starts off with the assumption that there are no other possible explanations for including FAR, SAR and TAR data.  I can offer a simple explanation.  How about the idea that they would be criticized if they didn't include them?

       I have a hard time fathoming why any half way intelligent person would read beyond this one statement in Tisdale's post, other that just morbid curiosity.

41796. Rob Honeycutt at 03:42 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Bob...  Tisdale randomly dismisses Tamino's point, that was clearly accepted by the IPCC as being correct, that it is not proper to baseline on a single anomalous year.

       This is exactly the problem with "leaked" versions of a draft paper.  Those who are so mentally inclined, like Tisdale, McIntyre and others, are going to divine nafarious intent where there is none.

       Tisdale also lacks the capacity to do actual statistical analysis to show his point,  something that Tamino is capable of doing and, in fact, did.

41797. Bob9499 at 03:16 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Dana, Bob Tisdale comments on your post:

       http://wattsupwiththat.com/2013/10/04/no-matter-how-the-cmip5-ipcc-ar5-models-are-presented-they-still-look-bad/

41798. Albatross at 02:36 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Hi OPatrick,

       No worries, we seem to have had a miscommunication. I think that we are on the same page now :)

41799. OPatrick at 02:29 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Albatross @23 - I never bought it as such in the first place, I just thought that Dana was mistaken to have said Curry had quoted the IPCC discussing the issue in the SPM, when she was actually quoting something which she felt (to be generous) had been left out of the Approved version. As we have both shown the replacement wording is not different enough to justify her criticisms.

41800. Albatross at 02:20 AM on 5 October 2013
       Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
       

       Opatrick @19,

       The following claim by Curry is demonstrably false:

       "Nowhere in the final WG1 Report do we see the honest statement that appeared...."

       Please read AR5 WG1 that was released this past Monday.  They say, and I quote:

       "Most simulations of the historical period do not reproduce the observed reduction in global-mean surface warming trend over the last 10–15 years (see Box TS.3). There is medium confidence that the trend difference between models and observations during 1998–2012 is to a substantial degree caused by internal variability, with possible contributions from forcing inadequacies in models and some models overestimating the response to increasing greenhouse-gas forcing."

       Now do you still buy Curry's claim as being correct?  I hope not.

       You also seem to be missing the point (I noted another problem with Curry's comment in my post @12 above).

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