by Nic Lewis
These comments constitute a response to erroneous statements and misrepresentations made in a report published by the Met Office in July 2013: “The recent pause in global warming (3): What are the implications for projections of future warming?” (the Report).
A significant part of the Met Office Report concerns what it refers to as a recent comprehensive study, being the 2013 Nature Geoscience paper “Energy budget constraints on climate response” (Otto et al). The Report contains several misrepresentations of the findings of the Otto et al study as well as a number of other misleading or erroneous statements.
The author team of Otto et al includes fourteen lead or coordinating lead authors of the forthcoming IPCC scientific report (AR5 WG1 report). The author of this memorandum, Nicholas Lewis, whilst being one of the authors of the Otto et al 2013 study, writes in a personal capacity, not as a representative of its author team.
The Met Office Report discusses in some detail estimates of transient climate response (TCR) and equilibrium/effective climate sensitivity (ECS). TCR, a measure of the rise in global surface temperature at the end of a 70 year period over which atmospheric CO2-equivalent concentrations grow at 1% per annum (and hence double), is closely linked to projections of human-caused warming several decades into the future. ECS measures the eventual surface temperature increase from such a doubling once ocean temperatures have fully adjusted. ECS largely determines TCR.
The Met Office Report considers whether climate model estimates of TCR and ECS need to be revised in the light of recent observational evidence, in particular the relatively slow increase in global surface temperature over the last 15 to 20 years. It concludes that, broadly, such estimates – and hence climate model projections of future warming – do not need to be reduced.
One of the Met Office Report’s main conclusions is that “the upper ranges of TCR and ECS derived from extended observational records … are broadly consistent with the upper range from the latest generation of comprehensive climate models” (CMIP5 models). This is contradicted by Otto et al, which stated “Our results match those of other observation-based studies and suggest that the TCRs of some of the models in the CMIP5 ensemble with the strongest climate response to increases in atmospheric CO2 levels may be inconsistent with recent observations”. Barely half CMIP5 models analysed (Forster et al. 2013) have TCRs below the 95% upper bound for TCR of 2.0°C given in Otto et al, using observational data for the latest decade.
These issues are of particular relevance to the Met Office. Both the TCR and ECS of its flagship HadGEM2-ES model, used for policy advice, are very near the top of the range for CMIP5 models (Forster et al. 2013) . Its TCR exceeds the 95% bound derived from CMIP5 models other than HadGEM2-ES. The HadGEM2-ES model’s TCR also exceeds the 95% bound derived from previous generation (CMIP3) models. The Met Office HadGEM2-ES model’s TCR of 2.5°C is not only well above the upper 95% bound of 2.0°C given in Otto et al, but also above the 2.3°C bound given in Gillett et al 2013 – the only other study cited in the Met Office Report that derived TCR from observational records. Indeed, the HadGEM2-ES TCR is nearly double the Otto et al best estimate for TCR of 1.3°C. As for ECS, the HadGEM2-ES model’s ECS of 4.6°C lies well beyond the upper 95% bounds given not only by Otto et al6 but also by Aldrin et al 2012 (3.5°C) and Lewis 2013 (3.0°C). HadGEM2’s ECS also exceeds the 4.5°C top of the IPCC’s ‘likely’ range, and the 95% bounds both from CMIP3 models and from CMIP5 models excluding HadGEM2-ES (Murphy et al. 2009).
The TCR of the Met Office’s previous generation climate model, HadCM3, is at the 95% upper bound for TCR of 2.0°C given in Otto et al. A perturbed physics ensemble study based on adjusting the parameters in HadCM3, now set out in two major published papers (Sexton et al 2012 and Harris et al 2013), represents the techniques and climate model on which the official UK Climate Projections (Murphy et al. 2009) produced by the Met Office were based. HadCM3’s high TCR might not matter if, as the Report claims, “uncertainty in the response of the climate system to CO2 forcing is comprehensively sampled” in the study. However, it is not. Despite thorough attempts to make it do so by varying its parameters, HadCM3 is unable to sample the region where, according to several recent observational studies, key characteristics of the real climate system are most probably located. It is therefore unsurprising that incorporating observational data barely alters the Harris et al 2013 prior central estimate for TCR.
Misrepresentations relating to transient climate response (TCR)
The Met Office Report refers to three methods of estimating TCR: from simulations made with climate models, from observations, and by combining climate model and observationally-derived values. It makes the contentious claim that none of these methods can be said to be superior to the others. In science, it is standard to test the validity of theoretical models by comparing their predictions to observational data. Accordingly, it seems possible to say that estimates derived purely from simulations by climate models, without combination with observationally-derived values, are likely to be inferior to those from the other two methods.
Figure 1 and Table 1
Figure 1 in the Report, which gives the Otto et al TCR 5–95% range as 0.7 to 2.5°C, most likely value 1.4°C, based on 1970–2009 data, is objectionable on a number of grounds:
1. Figure 1 does not use the Otto et al primary TCR best estimate of 1.3°C and 5–95% range of 0.9 to 2.0°C, based on data for the decade 2000–09. Although caution is required in interpreting results for any short period, arguably – as stated in Otto et al – the estimate based on the most recent decade’s data is the most reliable since it has the strongest forcing and is much less affected by the 1991 eruption of Mount Pinatubo. Accordingly, showing in Figure 1 only the (wider) TCR estimated range based on 1970–2009 data for Otto et al for comparison with other estimates is misleading.
2. Classifying the Harris et al 2013 HadCM3-perturbed-physics-ensemble derived TCR estimates as based on model and observations gives a misleading impression of the relative influence of those two factors. Although highly sophisticated, the study would more appropriately be classified as primarily model based. As HadCM3’s parameters are perturbed, the resulting changes in ECS and aerosol forcing are closely linked. When significantly lower values for ECS – as suggested by recent observational studies – are obtained, HadCM3’s aerosol forcing takes on highly negative values. The observational data strongly contraindicate aerosol forcing being highly negative, so parameter combinations resulting in significantly reduced model ECS levels (and thus highly negative aerosol forcing) are heavily down-weighted. As a result, whatever the actual level of ECS, HadCM3-derived ECS estimates are bound to be high. See Box 1 [refer to full document Lewis UKMO]. The HadCM3-derived TCR estimates are very largely determined by its ECS estimates, so the same is true for TCR. Since the Harris et al 2013 results largely reflect the particular characteristics of the HadCM3 model, and are at variance with results from several recent fully observationally-constrained studies, no reliance should be placed upon them.
3. The central TCR estimate of 1.6°C given for Gillett et al 2013 is a mean, and is not comparable to the median estimates quoted for Otto et al and Harris et al 2013. Since TCR and ECS probability distributions are usually skewed, the median – the 50th percentile of the distribution – is a much preferable central estimate for TCR and ECS than the mean (the probability-weighted average value). Gillett et al 2013 used a standard detection-and-attribution method, giving regression coefficients which can then be multiplied by the model TCRs to produce observationally-based TCR estimates. The median TCR estimate based on individual model regression coefficients was 1.46°C.
4. The multi-model CMIP3 and CMIP5 central TCR estimates given of 1.8°C are also means rather than medians. The median TCR for the set of CMIP3 models referenced is lower, at 1.6°C. (The mean–median difference is negligible for the set of CMIP5 models.)
Several of the TCR estimates given for Otto et al in Table 1 are wrong. The central TCR estimate based on the 2000s observational period is given as 1.4°C. It was actually 1.3°C. Several of the other TCR percentiles given are also wrong.
A revised version of Figure 1 in the Met Office Report showing the impact of the revisions discussed above, and a better idea of the distribution of probability, is shown in Figure 1.
Figure 1: Estimates of TCR from the same sources as in Figure 1 of the Met Office Report, with estimates based on 2000-2009 data added for Otto et al.
The flasks span the 5–95 % uncertainty ranges for the estimates from each source; the black horizontal lines mark their 50th percentiles (medians). The width of the flask shows probability density, in each case for the shifted lognormal distribution corresponding to the applicable 5th, 50th and 95th percentiles. Since flasks from all sources therefore have equal area, probability is proportional to area between as well as within flasks. Short white horizontal bars show the central estimate for each source given in Figure 1 of the Met Office Report. The red bar in the CMIP5 column shows the TCR of the Met Office HadGEM2-ES model. The colours denote type of source, with blue showing estimates based on observations, purple showing estimates based primarily on model but partly on observations, and salmon for model-only estimates.
Physical considerations
The Met Office Report states that “To reach the very low values [for TCR] quoted in Otto et al. (2013) would require negative feedbacks to be acting quite strongly to counteract the well understood physics of greenhouse gas radiative forcing, water vapour feedback and surface albedo feedback”. That is misleading. The strong negative lapse rate feedback is very closely linked to the water vapour feedback (they are sometimes combined into a single feedback) and has a similar level of understanding. Therefore, it should be included along with greenhouse gas radiative forcing, water vapour feedback and surface albedo feedback.
A multi-model study of feedbacks, Soden and Held 2006, showed a median ECS for the model ensemble of 1.8°C after combined water vapour/lapse rate and surface albedo feedbacks. The median 1.3°C and 1.4°C estimates for TCR in Otto et al both correspond to ECS estimates above 1.8°C, so are consistent with the Soden and Held 2006 findings without requiring any additional negative feedbacks to be acting. Moreover, real-world water vapour feedback may not be as strong as in typical climate model simulations. Although the basic physics of these feedbacks may be well understood, there remains substantial uncertainty as to their magnitudes. Furthermore, cloud feedbacks are highly uncertain.
Estimated warming at 2100
The Met Office Report miscalculates estimated warming at 2100 under the RCP8.5 scenario for all the studies shown, mainly by using inconsistent bases in the calculation. Figure 2 of the Report also contains an additional misrepresentation of Otto et al’s results. Both issues can be illustrated using the values for Otto et al. The 5–95% range given in Figure 2 of the Report for Otto et al, of 1.7–6.2°C with a median value of 3.5°C, is evidently based on multiplying the study’s TCR estimates based on 1970–2009 data by 8.5 Wm-2 and dividing by 3.44 Wm-2, the CMIP5 mean F2x level in Forster et al 2013, as used in Otto et al. The RCP8.5 scenario was so named because the resulting forcing approaches 8.5 Wm-2 in 2100. However, that was based on a different, higher, F2x basis. In fact, the RCP8.5 indicative forcings dataset (Meinshausen et al, 2011) gives a level of 8.34 Wm-2 in 2100, not 8.5 Wm-2, and it is based on a canonical F2x estimate of 3.71 Wm-2, not 3.44 Wm-2. So the RCP8.5 forcing in 2100 should be divided by 3.71 Wm-2, not 3.44 Wm-2, in order to estimate warming in 2100. Substituting that divisor in the calculation, and taking the indicative RCP8.5 mean forcing over 2095-2105 to even out the solar cycle, reduces the 3.5°C median 2100 warming estimate from Otto et al using 1970–2009 data to 3.1°C.
Moreover, the Met Office Report does not reveal that the warming at 2100 shown for Otto et al is based on its TCR estimates using data for 1970–2009 rather than its primary, arguably more reliable, TCR estimates based on data for the 2000s. Using those estimates instead, the median 2100 warming estimate from Otto et al under the RCP8.5 scenario becomes 2.9°C, with a 5–95% range of 2.0–4.4°C. Both the median estimate and the top of the 95% range are substantially lower than the figures of respectively 3.5°C and 6.2°C given in Figure 2 of the Report. Note that the statement in the caption thereto that medians are marked is incorrect for 3 out of 5 sources; it is means that are marked, except for Otto et al and Harris et al 2013.
Figure 2: Estimated warming at 2100 relative to pre-industrial levels under the RCP8.5 scenario.
Values are calculated as in Figure 2 of the Met Office Report but on a corrected basis and using the TCR values from Figure 1 above rather than from Figure 1 of the Report. The flasks span the 5–95 % uncertainty ranges for the estimates from each source; the black horizontal lines mark their 50th percentiles (medians). The width of the flask shows probability density, in each case for the shifted lognormal distribution corresponding to the applicable 5th, 50th and 95th percentiles. Since flasks from all sources therefore have equal area, probability is proportional to area between as well as within flasks. Short white horizontal bars show the central estimate for each source given in Figure 2 of the Report. The red bar in the CMIP5 column shows the Estimated warming at 2100 for the Met Office HadGEM2-ES model. The colours denote type of source, with blue showing estimates based on observations, purple showing estimates based primarily on model but partly on observations, and salmon for model-only estimates.
The use of inconsistent F2x bases and overstatement of RCP8.5 forcing at 2100 does not just affect the Otto et al study. All the estimated 2100 warming figures given for Gillett et al 2013, Harris et al 2013, CMIP3 and CMIP5 similarly need to be reduced by 10% in order to correct these errors. A revised version of Figure 2 in the Met Office Report showing the impact of these corrections is shown in Figure 2. As noted in the Report, RCP8.5 is the highest of all the RCP scenarios, which should be borne in mind when considering the projected Warming to 2100 levels in Figure 2.
The uncertainty ranges shown both in the Met Office Report Figure 2 and Figure 2 here are in any case exaggerated, since 25–30% of the decadal-mean radiative forcing projected under RCP8.5 for 2100 relative to pre-industrial levels has already occurred. Moreover, according to observational records, by 2012 the global mean temperature had increased by about 0.8°C. That is in line, scaling pro rata, with 25–30% of the medians for the Otto et al and Gillett et al projected increases to 2100. But the non-observational studies’ central warming projections need to be adjusted down to reflect their overestimates of the temperature increase to date.
Misrepresentations relating to equilibrium climate sensitivity (ECS)
Estimation of equilibrium climate sensitivity is dealt with in Section 4 of the Met Office Report. It repeats the misleading claim that “Positive feedbacks in the physical climate system, the largest of which is the water-vapour feedback, increase this number [ECS] to over 2°C”, and compounds this distortion by stating that “the fundamental physics of climate sensitivity, involving black body radiation and water vapour feedbacks … alone give a climate sensitivity of at least 2.0°C”. As already pointed out, these claims ignore the negative lapse-rate feedback, which is intimately linked to the water-vapour feedback. After including lapse-rate feedback as well as water-vapour feedback, all the models analysed in Soden and Held 2006 had a climate sensitivity of below 2.0°C.
The Met Office Report also claims, concerning the Otto et al ECS estimate based on data for the 2000s, that “As for TCR the observations of most recent decade are not representative of the full observational record and so not expected to be representative of the longer term future.” That claim is not valid. Decadal-scale internal variability of global temperature was allowed for in Otto et al. Moreover, the slower increase in surface temperatures during the 2000s was, as one would expect, associated with a higher estimated rate of ocean heat uptake, which increases the ECS estimate. The Otto et al ECS estimates based on data for each of the 1980s, the 1990s and the 2000s, and for 1970-2009, measured in each case relative to estimates for 1860–79, were all very similar. Indeed, the Otto et al ECS estimate based on 2000–09 data was actually the highest of those four ECS estimates, as a result of the top-of-the-range ocean heat uptake estimate used.
Figure 5 of the Met Office Report only gives ECS 5-95% bounds for Otto et al and CMIP3 and CMIP5 model ensembles. It is surprising that no other recent peer-reviewed observationally-based estimated ranges for ECS were shown. Examples are Aldrin et al 2012, Lewis 2013 and Masters 2013.
It is questionable whether valid estimates of probabilistic ranges can be constructed from an ensemble of simulations by different climate models. But even assuming so, Figure 5 of the Report indicates it does not show, as stated, the 5-95% ECS range for CMIP5 models given by Forster et al 2013. That range is 1.9–4.5°C, not 2.1–4.6°C. Moreover, the CMIP3 and CMIP5 central estimates are means, whereas those for Otto et al are medians.
A revised version of Figure 5 in the Met Office Report that does include several recent observationally-based studies, and corrects the CMIP5 ECS 5-95% range, is shown in Figure 3. All central estimates are medians to provide consistency. The range from palaeoclimate estimates (1.2–5.2°C) has been omitted since it is not on a comparable basis to the remaining ranges and palaeoclimate estimates involve great uncertainties.
It is evident from Figure 3 that a variety of recent observationally-based studies all produce median estimates for ECS that are very substantially below the CMIP3 and CMIP5 model-based estimates, indicating that ECS in the more sensitive CMIP3 and CMIP5 models, at least, is likely to be out of line with reality.
Figure 3: Estimates of ECS from the same sources as in Figure 5 of the Met Office Report, with those from Aldrin et al 2012, Lewis 20138 and Masters 2013 added and the Palaeo range omitted.
The flasks span the 5–95 % uncertainty ranges for the estimates from each source; the black horizontal lines mark their 50th percentiles (medians). The width of the flask shows probability density, in each case for the shifted lognormal distribution corresponding to the applicable 5th, 50th and 95th percentiles. Since flasks from all sources therefore have equal area, probability is proportional to area between as well as within flasks. Short white horizontal bars show the central estimate for each source given in Figure 5 of the Report. The red bar in the CMIP5 column shows the ECS of the Met Office HadGEM2-ES model. The colours denote type of source, with blue showing estimates based on observations and salmon for model-only estimates.
Conclusions
The Met Office Report contained a number of misrepresentations of Otto et al 2013, misleading statements and outright mistakes. Correcting these and providing a fairer analysis reveals that, although some of the recent observationally-based estimates of TCR and ECS considered have upper bounds to their uncertainty ranges that are comparable to those for model-based estimates, they all give lower best estimates than model-based best estimates. Observationally-based median estimates for TCR and ECS are often comparable to the bottom of model-based uncertainty ranges.
The statement in the Met Office Report that “the upper ranges of TCR and ECS derived from extended observational records … are broadly consistent with the upper range from the latest generation of comprehensive climate models” has been shown to be questionable. The TCR and ECS characteristics of the Met Office flagship HadGEM2-ES model are of particular interest in this regard. None of the 95% bounds for TCR estimates from the observationally-based sources cited in the Report exceed the TCR of HadGEM2-ES. And HadGEM2-ES has an ECS that exceeds not only the 95% bound from Otto et al but also that from two other recent observationally-based studies. Moreover, both the TCR and the ECS of HadGEM2-ES exceed the 95% bounds derived not only from CMIP3 models but also from CMIP5 models other than HadGEM2-ES.
It has also been shown that estimates based on perturbing parameters in the Met Office HadCM3 model, as exemplified by Harris et al 2013, do not sample combinations of ECS and aerosol forcing located in the region most supported by several recent observationally-based studies, and so cannot be regarded as properly reflecting observational evidence. That is of concern since these same techniques, using the HadCM3 model, represent the basis on which the official UK Climate Projections were constructed.
JC note: The complete document with footnotes and references can be downloaded here [Lewis UKMO], including Box 1.
The UK Met Office reports were discussed previously on Climate Etc. UK Met Office on the pause. The Otto et al. paper was discussed previously on Mainstreaming ECS ~ 2 C.
I greatly appreciate Nic Lewis’ efforts in auditing the UK Met Office report.
This is a technical guest post. Please keep your comments relevant and civil.
Three cheers for climate auditors.
Thanks Nic for detailed quantitative rebuttals, corrections & clarifications. The evidence Nic cites is making its way into the IPCC AR5 and the public media. e.g. Matt Ridley in WSJ Dialing Back the Alarm on Climate Change
I agree that there is value in Nic’s work – but it misses the main point: Since we do not know what natural factors were involved, we cannot use the observed temperature rise over that absurdly short period to estimate climate sensitivity to CO2.
a.k.a. Argument from Ignorance (Argumentum ad Ignorantiam)
i.e., the IPCC posits that we see no natural cause sufficient to explain the warming, therefore the warming must be anthroprogenic.
Ridley’s WSJ article is at: http://online.wsj.com/article/SB10001424127887324549004579067532485712464.html
Thank you Nic Lewis for speaking out.
NAS is also moving away from AGW:
http://junkscience.com/2013/09/13/manmade-greenhouse-warming-to-date-offset-by-uncertain-amount-of-manmade-cooling-says-national-academy-of-sciences/comment-page-1/
Omanuel—-I am not sure this from the NAS is really a movement away from AGW as much as it is an excuse to compensate for what they believe to be a rock solid absolutely certain effect of CO2 increase which temporarily has been nullified by the effect of humanities production of aerosols.
They are then certain that in the near future the effect of the aerosols will not increase but that of the CO2 will increase, at which time we will go back to the warming. That is why it is referred to as a (temporary) pause and not a stop in warming.
I am learning as much about human nature as I am about science.
Thanks, darrylb. Consensus (aka standard) models are Orwellian tools of mind control – stacked into a house of cards because FEAR of nuclear annihilation separated world leaders from reality in 1945 !
3. The consensus model of AGW depends on
2. The Standard Solar Model that depends on
1. Attractive forces between neutrons, instead of
0. Repulsive forces that caused atomic explodes in 1945.
https://dl.dropboxusercontent.com/u/10640850/Creator_Destroyer_Sustainer_of_Life.pdf
Nick,
The Met office report is a political document. Your arguments, while technically relevant and clear, seem to me orthogonal to the issues the Met document is trying to address; to wit, lower empirical estimates show that the CMIP ensemble, and the Met GCM in particular, are essentially without value for projecting future warming. This is a political problem for the Met (and the UK government), because they are absolutely committed to mandated draconian reductions in fossil fuel use in the UK, justified by projections of extreme future warming. Any reduction in the consensus best estimates of transient and equilibrium responses could undermine political support for those reductions in fossil fuels, and add to political support for extensive use of fracking technology to recover large reserves of natural gas in the UK.
The goal of the report seems to me only to cloud the water with very questionable claims which will delay public perception of a new scientific consensus on lower sensitivity; they simply want to delay changes in public opinion for as long as possible. While I think this sort of thing being done by scientists is reprehensible, it is certainly not unexpected for scientists with one foot in science and the other in political advocacy. I think you can count on several other climate science/political advocacy organizations doing much the same as the Met.
If the MET document is a political document, one has to wonder what Nic has just produced.
yes one can wonder. But one need not wonder. If you choose to wonder what would you wonder.
When will willard wonder well?
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willard(@nevaudit): If the MET document is a political document, one has to wonder what Nic has just produced.
I don’t think I had to wonder, but I did wonder. hmmm — A scientific critique of summaries of scientific research in a political document?
A good, thorough and effective critique, I have to add. Thank you to Nic Lewis. This is an example of a citizen stepping up to audit a govt-produced research summary.
Come on Willard. Nic Lewis simply stated the facts of a study in which he was involved. Then he pointed to the fact that the findings of that study were misrepresented. Many of us are trying to be objective, but your statement goes beyond the 95% probable boundary of incredulity.
It honestly makes other statements you make less believable, and I am sure you do not intend to do that.
That one being you Willard?
Willard, lots of people go on to have normal lives after they leave a cult;
a bit of deprograming and you will be fine. However, the staring point is that you have to accept reality to be true and not some ‘mumbo-jumo’ as the fundamental reality. The first step is the most important, admit you have a problem reconciling you belief system with reality, then all will follow.
http://www.intervention101.com/
Why is the MET report a political document?
Many thanks!
wandering wondering willard.
“Why is the MET report a political document?
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so many questions,, why do wonder? Or perhaps we can reach agreement this way.
Lay out the evidence you would have to see to conclude that it was a political document or evidence you would have to see to conclude it wasnt.
To the rest of us, your questions is like “Why is Up the opposite of down”
The fact that you question the obvious leads me to believe that you have a different idea of what counts as political. To test that, we need to see your idea of what counts as political.
Willard: If Nic Lewis’s critique is correct and complete, then the MET made a number of errors and misrepresentations in its report, all tending in the direction of making the situation appear more alarming AND supporting the validity of their own climate model as Steve Fitzpatrick noted. A non-political document would be more likely to have errors pointing in both directions. So the one-sidedness of the errors is evidence tending to confirm the hypothesis that the MET document was biased in the direction of alarmism and supporting their own work product. (If Nic’s memo leaves out instances where they erred in the other direction, then the evidence would be less compelling.)
Dear Moshpit,
Thank you for making me realize I wrote “two” whence I should have written “three”. I already acknowledged it. You are wrong to claim that I miscalculated, as I assure you that the fumble is a result of my Android tablet creating a wormwhole in the text when I delete two or three times, which renders my comments uneditable.
It’s OK, I will own it.
***
You should stop, now, as you’re putting someone else’s business on the line. My first intention was to illustrate the dogwhisting that goes by underlining that the A’s “misrepresentations” are undetermined and by hinting at the A’s adverbs, some of which have little to do with a technical analysis. I will now follow through my reading of this op-ed thanks to you, among others.
Please do continue.
Steve Postrel,
You say:
> A non-political document would be more likely to have errors pointing in both directions.
I have no idea why this criteria would separate non-political documents from political ones, but here’s what James Annan concluded a while ago about a related analysis by the A:
http://julesandjames.blogspot.ca/2013/02/a-sensitive-matter.html
My emphasis.
I’m not sure I would use one-sidedness as a criteria to measure the political content of a document, as it might have lukewarm consequences on the way we should interpret the constant fight to push down sensitivity.
Willard:
1) How can you have “no idea” why independent errors all pointing in one direction suggest political intent? By definition, it shows bias. Now you just have to see what kind of bias is most plausible. In this case, the MET’s errors, if undetected, would work to defend its own modeling product and its past conclusions. Why did the chicken cross the road? Maybe it was a fit of inattention, but most likely it was trying to get to the other side.
2) James Annan does well to consider the possibility that Nic Lewis is shading his findings toward lower sensitivity. Of course, Lewis might say that Annan is shading his interpretation of the evidence toward higher sensitivity. The key difference is that in the quotation you offer, Annan does not identify any error or misrepresentation on Lewis’s part, merely differences of opinion about the quality of different pieces of evidence. In the post here, Lewis identifies specific misstatements about what others have actually claimed and errors in plugging in the wrong numbers. Horse of a different color.
willard gives it away with ‘constant fight to push down sensitivity’. No, willard, just wandering the world observing.
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One need not look at it as a political document. One could also suppose that they don’t want their models thrown out of the ensemble of models used – even though they arguably should be. The report can thus be looked at as more of a reflexive, self-protective measure. Just to annoy some people, I will paraphrase Feynman from his Cargo Cult science lecture: A scientist has to have a certain type of honesty. After all, it is easy to fool yourself. One needs to bend over backwards to look at your own data in a critical light and report all its shortcomings as well as its strengths.
They didn’t even have to bend over backwards to understand that the water vapor feedback was exaggerated. They’ve been told that for years. Furthermore, the pretzels they twisted themselves into(aerosols, deep missing heat) are now becoming much more excruciating than the simple bend backward needed at the outset.
Santer claws;
Ouch, that pause.
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Steve Postrel,
You say:
> How can you have “no idea” why independent errors all pointing in one direction suggest political intent?
First, they’ve been called “misrepresentations”, not “errors”, because the author focus on claims he considers misleading.
Second, they have not been shown to be independent, something that affects their accounting.
Third, there are lots of different bias, some of which are not ipso facto erroneous.
Calling these so-called independent errors “misrepresentations” shows a very big auditing bias, insofar as we see the same pea and thimble game where an auditor uses technical nits to dogwhistle his editorial.
***
Even you do shows this auditing bias when you say:
> Lewis identifies specific misstatements about what others have actually claimed and errors in plugging in the wrong numbers.
The fact that the Met messed up their table 1 is quite independent from the dispute about which kind of estimates is the best ones, if negative feedbacks should be considered physical, if we should use medians or means, or else, which constitute most of the A’s criticisms.
I hope you do realize that playing this kind of pea and thimble game shows more political intent than making technical decisions which do not exclude possibilities some like you may lukerwarmingly frown upon.
***
Just think about what entails your claim that political intent is shown when there’s a systematic bias in one direction:
(1) Lukewarmism positions itself as the lowest CS justified disingenuousness can buy.
(2) Lukewarmism plays the ref against anyone who’d bid above them.
You can sure continue your special pleading according to which systematic errors are the True Scotsmen of our silly story.
Thanks Nic! The audit states that “cloud feedbacks are highly uncertain.” I would be interested to learn to what extent cloud feedback is now better constrained using up-to-date observational data than it was, say, ten years ago.
The last thing the warmista want to do is better constrain cloud data. It would reveal that clouds absorb around 15-25W/m^2 more than the microphysics says they should, and that will invalidate all the models.
http://tallbloke.files.wordpress.com/2012/11/cess.pdf
Let me know when main stream science realizes that the climate sensitivity of CO2 is indistinguishable from zero. Until then this is “All sound and fury, signifying nothing” Macbeth, William Shakespeare.
Jim, you will be dead many times over before main stream science would ever admit to such an erroneous idea, or we’ll have returned to the dark ages ruled by wacko right-wing nutters who will teach that the Earth is only 7000 years old.
What about the wacko wingless nutters who will teach that the carrying capacity of the Earth has already been exceeded?
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R.Gates, you write “or we’ll have returned to the dark ages ruled by wacko right-wing nutters who will teach that the Earth is only 7000 years old.”
By that I take it to mean you equate me with people who believe the world is only 7000 years old. I sort of resent that. I have stated over and over again, that I rely on empirical data, and empirical data only. There is ample empirical data on what the true age of the earth is. So how you can equate me with such an erroneous idea, I have no idea.
The little empirical data that we have, gives a strong indication that the climate sensitivity of CO2 is indistinguishable from zero. Now if you can produce some empirical data which shows that this is wrong, I would,be grateful. ALL the numbers associated with the climate sensitivoty of CO2 are either estimates and not measurements, since we cannot do controlled experiments on the earth’s atmopshere; or they are things like paleo data, where there is no proof that the alleged rise in temperature was, in fact, caused by the rise in CO2 levels, and not the other way around.
Do you have any measured, empirical data to prove that I am wrong?
Those whacko nutters who believe God created the heavens and the earth 10,000 years ago are the central actors in Western civilization and nutter headquarters, the United States of America, which boasts a higher percentage of said believers than any other western nation, is by far the greatest military and economic power on the planet.
Never argue with success, dumbass.
The moral of my story is that believing in a young earth does not restrain science and technology. In fact it appears to accelerate it and I would put forth the reason as those people don’t waste time wondering if birds evolved from dinosaurs but rather wondering how they might help free the oppressed, feed the hungry, and do God’s good work in every way they can.
Write that down.
You gotta understand the RGates responds to his fervid religious belief that the world is overpopulated. Unfortunately, the religion is primitive, doesn’t really believe in observational science, rather believes in a narrative of fear and guilt, which narrative is leading them into the swamp.
=========================================
Cripwell is in his 80’s. Late 80’s if I’m not mistaken. Your comment is in very poor taste. You’re an assbag among assbags, Gates.
Thanks for decoupling lapse rate from specific humidity itself. Observationally, the CMIP3 and CMIP5 model ensembles overstate humidity ( by an average of at least 10%) and understate precipitation (by as much as half, depending on which paper one chooses to believe most). The reasons are almost certainly owing to Lindzens adaptive iris hypothesis about tropical convection cells — Tstorms. There is more rainout, so more top of cloud residual latent heat to radiate away, and less humidity available to the upper troposphere where it matters most for positive water vapor feedback. Put differently, a negative lapse rate feedback via a specific mechanism.
And AR5 SOD (leaked) chapter 7 (clouds), explicitly says that given supercomputer power limitations, sufficiently small grid scales to resolve such convection cells and model this phenomenon are not possible, and may never be.
In other words, the essential negative lapse rate helping to explain oversensitivity cannot be adequately modeled in present GCMs, so any IPCC conclusions based on them are necessarily off.
Powerful though they be, these modelers’ supercomputers are but pitiful digital simulacrums of the great analog computer that is the heat engine that is the Earth.
============
I wanted ‘pitiful, pusillanimous, digital simulacrums’, but Barbara Frietchie flew a flag.
H/t Mary Quantrell
=========
“Seems the news of my warming through net amplification
by water vapour feedback was greatly exaggerated.”
Planet Earth ter Met Office.
That signal’s been broadcast for a long time, but alarmists’ antennae are deficient. They’ve been warned, but they don’t get alarmed.
====================
The answer is, of course, 42.
The overprediction of the tropical upper hot spot shows that the models are overdoing the negative lapse rate feedback, if anything.
JimD, “The overprediction of the tropical upper hot spot shows that the models are overdoing the negative lapse rate feedback, if anything.”
More like the modelers “ASSUMED” water vapor would do things it doesn’t.
It follows from their tropical ocean surfaces warming too easily, natural variability, ocean circulations, and all that.
Jimd, “It follows from their tropical ocean surfaces warming too easily, natural variability, ocean circulations, and all that.”
So they screwed up. Now have them put on their big boy pants and admit it.
They have a sensitivity range for a reason. The global temperature behavior is within their stated uncertainty, but I suspect the Arctic sea-ice loss was outside what they expected because ice-sheet modeling is a tough problem, being how much more susceptible it is to feedbacks than other parts of the system.
JimD, “They have a sensitivity range for a reason.”
It may or may not rain tomorrow. Is that useful? Now look at that range of uncertainty, 1.5 to 4.5 or up to 1.5 per CO2 doubling with up to 3.0 wild ass guessed water vapor feedback with clouds being only positive, because one guy disagreed with the original consensus to inflate the impact. The only reliable information is that CO2 equivalent forcing of 3.7 Wm-2 will produce a surface temperature increase of 0.8 to 1.2 C degrees. There is zero reason to assume clouds are a globe positive forcing or that water vapor will follow anyone’s script. Zero reason to assume 1951-1980 is “normal”. Zero reason to assume everything that disagrees with the models is wrong. Zero reason to assume that the guys in charge so far deserve to remain employed.
captd, so you have decided not to agree with even Nic Lewis that there is a 60% positive feedback that he thinks he has observational evidence to prove. You are in a dwindling minority. Is there some aspect of the Lewis work that you think is weak?
JimD, ” Is there some aspect of the Lewis work that you think is weak?”
The assumption that 1951-1980 was normal.
http://redneckphysics.blogspot.com/2013/08/is-picture-worth-trillion-dollars.html
In other words, it does not consider longer term (>100 years) climate impacts.
I agree that short-term studies are very limited in what they can say about the next century.
Jim D said:
“The overprediction of the tropical upper hot spot shows that the models are overdoing the negative lapse rate feedback, if anything.”
—–
You realize that the enhancement to the Brewer-Dobson circulation as predicted by some models (but not all) has been seen and is related to more vigorous tropical troposphere vertical motion. This would tend to decrease the “hot spot” effect over the tropics, and also decrease the wind speed of the QBO. All this relates back to increased GH gas forcing.
Jim D, that is the ultimate result. What is amazing is that MITs Lindzen explained why a decade age. His paper was explicitly rejected by AR4. Nic Lewis re-identified it in another guise, since AR4 chose to treat specific humidity and it’s lapse rate as one, since special box 8.1 (previous guest post here) treated them as one. So there is a negative lapse rate feedback to water vapor, which AR5 WG1 SODsays CANNOT be modeled at all, because of grid scale limitations. QED
The foundation of all climate science rests on our ability to explain the 33C discrepancy between the non-GHG atmosphere Earth and what we currently observe.
Skeptics always seem to massively fail when this is factored in. About 1 part on 3 is due to CO2, perhaps 1.5 part in 3 is due to associated water vapor increases, and the rest due to other GHGs and albedo changes.
When more CO2 is added, the 33C number is accordingly scaled upward. A doubling of CO2 adding only 3C to this number is the result of the log sensitivity .
Sceptics will need a theory to explain this better than the consensus has done.
The negative lapse rate feedback is well known and easily quantified thermodynamically being a consequence of how the upper part of the moist adiabat changes with temperature. As long as GCMs can maintain realistic moist adiabatic lapse rates, and they can, they would have no trouble with this particular feedback.
The lapse rate feedback has a clear physical justification, but it seems to be the case that lapse rates are more widely near to 6.5 C/km than simplistic arguments lead to think. We would expect significantly higher lapse rates where humidity is well below 100% and somewhat lower in areas of high humidity. The actual variability appears to be less than such arguments predict. It seems that winds and other mechanisms that cause lateral mixing must be involved in that.
To me it appears plausible that something similar may affect the lapse rate feedback. If the lapse rate is laterally more uniformly close to a single “environmental lapse rate” than naively expected it might also be less sensitive to warming than expected.
Even if my speculation (and it’s pure speculation) is true, that doesn’t necessarily affect much the combined effect of water vapor feedback and lapse rate feedback.
Pekka, “To me it appears plausible that something similar may affect the lapse rate feedback. If the lapse rate is laterally more uniformly close to a single “environmental lapse rate” than naively expected it might also be less sensitive to warming than expected.”
The main issue is the situation below the atmospheric boundary layer and above. You have an average of nearly 2.5km of highly turbulent mixing where convective mixing caps the ABL in the heat of the day and a moist air dominate temperature inversion caps it at night. It is referred to as the Water Vapor Greenhouse Effect. Above the ABL you will have the classic lapse rate. The models are basically defining the “surface” as some point ~3000 meters above sea level but using sea level temperatures to drive the CC estimates of water vapor. It doesn’t work that way when the majority of the surface on Earth is sea level oceans.
A fact that helps here is that the tropical troposphere has a lapse rate that stays very close to moist adiabatic, and therefore the tropospheric profile is closely tied to the surface temperature there. This lapse rate is a consequence of the radiative-convective equilibrium that dominates in the tropics where horizontal temperature gradients are weak. In tropical temperatures, as the surface of the moist adiabat warms, there is a slightly faster warming of this adiabat in the upper troposphere. This extra warming leads to more outgoing longwave radiation which is a negative feedback compared to if the lapse rate did not change. Held and Soden have had good explanations of this back to 2000 or so.
JimD, “A fact that helps here is that the tropical troposphere has a lapse rate that stays very close to moist adiabatic, and therefore the tropospheric profile is closely tied to the surface temperature there.”
Right and since the moisture in the tropical atmosphere at the ABL stays near super saturation, you won’t see much change in the tropical lapse rate. Do you expect CO2 to create a new super duper saturation?
captd, the tropical lapse rate is a function of surface temperature. I do expect a change in surface temperature, don’t you?
The argument is clear. According to this picture the profile appears, indeed to be close to moist adiabat in tropics. (Constant moist potential temperature means that the lapse rate follows the moist adiabat.)
Some other data on the temperature profile of tropical atmosphere tells, however, about a lapse rate close to 6.5 C/km at altitudes where the moist adiabat would lead to a considerably smaller lapse rate. I’m puzzled about this conflict between various data sources that I have seen.
JimD, “captd, the tropical lapse rate is a function of surface temperature. I do expect a change in surface temperature, don’t you?”
Over a few hundred years, not much. If you check the TAO data it has surface air and sea temperatures with relative humidity. When the humidity is at 85% and the SAT at 29C, the nocturnal atmospheric boundary layer is saturated at 25C degrees.; If you want that temperature higher but at the same altitude, you have to add pressure. If you add more water vapor, to already super saturated air, you don’t need cloud condensation nuclei, it will just rain anyway. If you add heat (any type of forcing above) you just create deeper mid level convection. CO2 does not change the properties of water.
Here is a page I found with an illustration of how the lapse rate varies with temperature.
http://clivebest.com/blog/wp-content/uploads/2013/02/Greenhouse3.png
Actually in very cold temperatures, the lapse rate is almost dry (near 10 C/km), but as you add moisture this lapse rate steepens, and this effect changes faster nonlinearly with temperature because of the nonlinear increase of saturated water vapor with temperature.
As discussed earlier, that claim simply wrong. The partial pressure of water vapor must be higher, but that is possible for any atmospheric pressure.
Thermodynamic properties change enough to modify the moist adiabatic lapse rate and the lapse rate depends also on the atmospheric pressure, but the consequences are nothing like what you claim.
Pekka, ” I’m puzzled about this conflict between various data sources that I have seen.”
Any change with current forcing would be feet or meters in one of the most turbulent regions of the atmosphere. One long term radiosondes study indicated a slight decrease in the cloud base (ABL) but that is challenged because the data doesn’t jive with model predictions, LOL. It doesn’t change the fact that super saturation is a pretty firm limit.
Just a remark.
The concept of steepening is confusing as that means that the lapse rate is reduced. In many ways it would be easier to discuss plots with a vertical temperature axis as we discuss the dependence of temperature on the altitude.
Supersaturation is certainly a strong limit, but that relates the absolute humidity to the temperature and has nothing to do with atmospheric pressure (except through temperature).
Pekka, yes, the word “steepening” was just referring to the diagram, but the lapse rate decreases in magnitude as it gets warmer, or gets less negative.
Pekka, “As discussed earlier, that claim simply wrong. The partial pressure of water vapor must be higher, but that is possible for any atmospheric pressure.”
Pekka, you are trying to initiate change from a stable saturated condition. If you add more heat you stimulate convection, add more water, precipitation. Where are you going to magically add heat?
Pekka, “Supersaturation is certainly a strong limit, but that relates the absolute humidity to the temperature and has nothing to do with atmospheric pressure (except through temperature).”
No, it relates to the actual operating condition of the system. The difference between the SST and MAT is about 0.8C. There is not a lot of room for warming without changing the convection rate of the precipitation rate and both are a negative feedback to surface temperature. That is what you have to work with. Now how do you change that so you have a warmer surface with more water vapor and not change convection or precipitation?
Check a psychrometric chart for 2250 meter altitude. In the tropics, if the lapse rate is continuous from the actual surface, the temperature at 2250 meters would be 14.65 C lower than the surface. With an average tropical SST of 29C that would be 14.35 C degrees and super saturated in the afternoon/night.
This is a study I did of lapse rate changes since 1960:
http://theoilconundrum.blogspot.com/2013/07/expansion-of-atmosphere-and-ocean.html
What gets tracked is the geopotential height H at 500 mbar and the surface temperature over the years
If we select a lapse rate, L, for 1960 of 0.0051°C/m, we calculate H = 5647.9m for P(H)=500 mb.
If we select a lapse rate, L, for 2010 of 0.0050°C/m, we calculate H = 5668.4m for P(H)=500 mb.
There is enough information to calibrate the surface temperature and the geopotential height using the barometric formula. The lapse rate is subtly reduced over the years, by a value of only 2%, but the temperature differences at altitude do shrink.
In 1960, the temperature difference at 500mb altitude is 0.0051°C/m * 5647.9m = 28.80°C
In 2010, the temperature difference at 500mb altitude is 0.0050°C/m * 5668.4m = 28.34°C
The difference at sea-level from the chart is 15.4°C-14.65°C = 0.75°C whereas the difference at the 500mb altitude assuming the modified lapse rate is 0.75°C – 0.46°C = 0.29°C. If the lapse rate didn’t change then this sea-level difference would maintain at a constant atmospheric pressure isobar in altitude.
There is no substitute for trying to fit the numbers according to the long-standing model.
Jim d says
I suspect the Arctic sea-ice loss was outside what they expected because ice-sheet modeling is a tough problem,
That’s very brave of you .The changes in the model (HadGEM1 to2) are by using corrections to the physics from better observations, and albedo changes by parametization schemes as proposed by the proprietor ( Curry 2001)
CD,
I agree that the mixed layer is different from the rest of the troposphere, and that this difference should be taken into account. My reaction was specifically against your statement you have to add pressure as you appear to be using that as a strong constraint related to the ambient air pressure.
Changes in pressure are important when pressure differentials that affect circulation are concerned, but the overall ambient pressure levels have only a small influence on the relevant thermodynamics, because N2 and O2 remain by far the dominant constituents under all imaginable conditions, and because they are also nearly ideal gases under atmospheric conditions. Condensation and evaporation of water are important processes, but they are controlled by absolute humidity and temperature, and affected very weakly by the ambient pressure when temperature is taken as an independent variable.
This modern warm period has warmed much the same as the Roman and Medieval Warm periods warmed. In the past ten thousand years there were warm and cold periods that have always alternated,warm then cold then warm then cold.
They tell us that alternating was natural variability then, but now, that has stopped and this Modern warming would have not happened without man-made CO2.
I have asked, “why should we have not warmed just like we have done for ten thousand years and why will we not cool again like we always did.
They tell us that it is warmer now than in those other warm periods. The data does not show that. Only model output shows that.
They have used their models to build a Hockey Stick that is ten thousand years long.
They must explain why natural warm and cold alternating periods should have stopped so that only CO2 can cause a warming just like happened after every cold period before and only a lack of CO2 can cause a cooling just like happened after every warm period before. CO2 has replaced natural variability in Climate Control and they can’t tell us what it was that was replaced.
Climatology has come to the point now where it like we’re hiring experts to paint talismans on flat roofs where they can best be appreciated by passing gulls.
> The Report contains several misrepresentations of the findings of the Otto et al study as well as a number of other misleading or erroneous statements.
How many of each?
42
I counted 37 and 19.
ok, I didn’t really count. Didn’t think it was a match with score keeping.
timg56.
I bow to your superior auditing skills. Its looks like we have a consensus then 37 and 19.
100% of auditors agree.
Steven,
On this blog I doubt I have any skill that is superior when compared to the commenters who regularly contribute here.
But I thank you for the complement, if that is how you meant it.
PS. We do have agreement, if not consensus that Willard is groping when he asks for a number.
Asking for a number of misrepresentations is the easiest way to show that the main theme of this op-ed (“misrepresentations”) acts more like a political hit job than a technical analysis.
By confusing errors with claims he finds misleading, Nic Lewis is using an old auditing trick.
Anyone who “read the blog” should know that trick.
Auditors are having problems with their accounting, it seems.
A political hit job would use “several” to inflate its rhetorical effect.
It would repeat it, and again, and again.
> These comments constitute a response to erroneous statements and misrepresentations […]
Which of “and” is this?
Which kind, that is.
There is a difference between commenting on erroneous statements that are also misrepresentations and commenting either on erroneous statements or misrepresentations.
there is? Could you explain
Largely, and to himself.
======
Willard,
Huh?
Longer version – have you gone from squirrel hunter to squirrelly?
If the A claims that each of the MET statements are erroneous AND misleading AND misrepresentations, then he has more work to do than to claim that such statement is erroneous, such other statement is misleading, and such other is a misrepresentation.
Also note that showing that a statement is erroneous entails another kind of analysis showing that it is misleading or a misrepresentation.
willard what makes you think that AND always means AND.
it depends on the meaning of AND.
I’ll assume charitiable interpretation which makes what the speakers say “true and interesting” perhaps you want to argue that it makes no sense.
Despite a strenuous effort, willard too often makes no sense at all, except to himself.
Nice Doggie; have a bone.
================
“willard what makes you think that AND always means AND.
it depends on the meaning of AND.”
You got Bill Clinton lapped.
> what makes you think that AND always means AND.
Nothing makes think that. If I thought this was the case, I would not ask the question I’m asking.
You misread me, Moshpit. Own it.
‘Nothing makes think that. If I thought this was the case, I would not ask the question I’m asking.
You misread me, Moshpit. Own it.”
Sorry asking a question doesnt imply a reading. Asking a question is a tool that you can use to force another statement out of people.
it can look like a mis reading, but doesnt entail a misreading
lets audit willard
The Report contains several misrepresentations of the findings of the Otto et al study as well as a number of other misleading or erroneous statements.
What does this mean
the report contains several ( usually taken as 2 or more ) misrepresentation of Otto
as well as ( in addition to ) a number ( unspecified quantity) of other
misleading or erroneous statements.
The Report contains several misrepresentations of the findings of the Otto et al study as well as a number of other misrepresentations or erroneous statements.
the key is understanding how the word “other” functions.
Willards closet includes hi heeled pumps and other shoes.
Willards closet includes hi heeled pumps and other female attire
Willards closet includes hi heeled pumps and other oddities.
the way I would read the author, to be charitable, is that there are several (more than 2) statements made about Otto that he wants to correct and a few others beyond otto.
Trying to turn the text on the various readings of misrepresentation, misleading, erroneous, is not very illuminating. At worst, what we discover is what we already know.
I am going to assume most of us who have commented here have read the aforementioned work of Nic L. above.. I am curious as to how many of us have the due diligence to have read the entire document including sources of information. I have not, I think I am too lazy– and also have been playing 500. Just curious!
> The Report contains several misrepresentations of the findings of the Otto et al study as well as a number of other misleading or erroneous statements.
This bears on repeating, it seems, since the A says so twice in his first two sentences.
Except perhaps that to misrepresentations and erroneous statements, we have misleading statements.
Auditors ought to wonder what readers should remember, if they have to remember one thing.
count the sentences again.
Done.
The A mentions “misrepresentations” in two of the first three sentences.
The second time, the A adds “several”.
willard, you are off to a horrible start auditing.
counting sentences and making an audit mistake does not bode well for you.
plus you forgot to give me credit for pointing out your audit error.
If you cannot play the position, get back on the bench.
I blame my tablet, which keeps deleting random words when I edit my comments.
I made an error. I acknowledged it.
Please do continue while nothing gets acknowledged from the op-ed, which Steve Fitzpatrick should interpret as a political publication.
A food fight won’t save you this time.
your tablet? your blaming your tablet,
You need to show some integrity and honor and thank me for pointing out your error. It’s pretty simple. Not a food fight. But as long as you want to deny the obvious, then food fights are fine. Someone who cant even acknowledge others is hardly a good partner for dialogue..
Aw, c’mon, he’s a fun punching bag as long as he believes the politicized alarmist sites he’s reading from. He’d have figured that out by now if he could audit.
================
> your tablet? your blaming your tablet,
Not really.
You should see what the tablet does. You enter letters and words disappear. It’s maddening.
I did own my error. Thank you.
You should see what the tablet does. You enter letters and words disappear. It’s maddening.
Have you thought of asking your GP to halve the dose?
I will have willard’s back here. Touch screen tech, whether phone or tablet, allows for all sorts of errors.
The error was mine, Tim.
My tablet’s behaviour shows a very nasty bug. The editor loses track of its cursor when CR or LF gets deleted. This has the effect to delete whole words and keep the insertion point at a random place. Anyway.
Typing HTML code on such a device might not be the best practice.
There’s a worse bug in your tablet/brain machine; it only lends credence to politicized alarmist sites.
================
A touch pad with blue photons, willard? Not, know Neven?
Opera does not seem to have that problem. We’ll see.
But it has others, e.g. no copy-paste of comments.
willard(@nevaudit): Auditors ought to wonder what readers should remember, if they have to remember one thing.
gracious.
Is this your way of affirming that you have read the entire document (link provided by Prof Curry) and have found no error worth reporting?
MattStat,
I don’t think I need to show any error in Nic’s analysis to show that it is a dogwhistled hit job. I’ll let the MET Office answer for their work.
Nic should have published it at the Auditor’s, where he would have had diplomatic immunity.
Thanks for playing, though. Your interventions will prove useful later on, if only to show how technical bullying works.
willard(@nevaudit): I don’t think I need to show any error in Nic’s analysis to show that it is a dogwhistled hit job
You don’t even show that it is a dogwhistled hit job.
Speaking of misrepresentations has nothing to do with a technical analysis.
Weaseling one’s way out of one’s analytical duty with adverbs does not help either.
And that’s just the beginning.
Thank you for your concerns, MattStat.
Willard(@nevaudit):Speaking of misrepresentations has nothing to do with a technical analysis.
Never? Not even when the MET authors misrepresented the technical results of technical reports?
> Never? Not even when the MET authors misrepresented the technical results of technical reports?
Wait until the echo chamber kicks in. You should not have to wait for long.
Show me an example from the op-ed of such technical result that the Met has been said to be misrepresenting. I surmise you will get a misrepresentation that is not that “technical”.
willard, the models have failed. Start over. Do not collect your 200 dollars.
==============
See also:
http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-380652
And also:
http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-380892
I believe MattStat’s “you don’t even show that it is a dogwhistled hit job” has no merit.
Willard,
What does a dog-whistle sound like in an echo-chamber?
Willard,
misrepresentation of the findings (of the paper)
a number of other misleading and erroneous statements (which may not be directly about the paper).
Not yet had your morning coffee?
Yes, thank you.
No, your distinction cuts no ice and does not answer what I’m asking.
Then ask it more clearly.
What were the misrepresentations, Tim?
willard when you can tell the difference between the first two sentences and the first three sentences, then get back to us. Oh yes, and you need to add the credit to Moshpit.
Next up, I’ll get to play race horse
You’re in no position to tell me where to sit. Keep your ad hominems and your fantasies to yourself.
willard,
Its clear that you miscounted sentences. you want to be an auditor you have to show integrity and give credit to Moshpit who pointed out your error.
If you cannot own the simplest error why should be try to convince you of your other errors?
So, you get to start by saying
“Thank you Moshpit for pointing out my stupid error. I will go and sin no more”
Say that willard. I’m ordering you.
Careful, moshe; he’ll snarl.
============
I already did acknowledge my error.
> If you cannot own the simplest error why should be try to convince you of your other errors?
This is how the auditing gambit works in a nutshell.
INTEGRITY ™ — From Nits to Integrity
No willard, your explanation doesnt fly. We want a full accounting of your mistake. You know the kind Joshua wanted from peter lang.
explain exactly how your laptop had anything to do with the miscounting?
no copy and past was required. Ask yourself this. I read the document.
I read your description of the first two sentences. I knew it was wrong without even CHECKING. why? because I read the document. maybe you should get checked for a memory disorder.
So you wrote your comment. did you double check before posting?
or double check after posting?
If your tablet has a problem with copy and paste have you noticed it before? if so, then why didnt you check? perhaps you were in a rush to spam the thread..
The IPCC does a dial back. [leak]
http://online.wsj.com/article/SB10001424127887324549004579067532485712464.html
A small first step, but at least some progress toward accepting reality. Maybe the next step will be bigger.
Beyond blue and yer move into the TCR psychodelic zone.
> The author of this memorandum, Nicholas Lewis, whilst being one of the authors of the Otto et al 2013 study, writes in a personal capacity, not as a representative of its author team.
I thought these were commentaries, not a memorandum.
I also thought the A was Nic Lewis, not Nicholas Lewis.
No discussion between the A, the authors of Otto & al , and the Met office is being disclosed. If there were none, that should be said. If there were some, we should be able to read it.
> The Met Office Report discusses in some detail estimates of transient climate response (TCR) and equilibrium/effective climate sensitivity (ECS). TCR, a measure of the rise in global surface temperature at the end of a 70 year period over which atmospheric CO2-equivalent concentrations grow at 1% per annum (and hence double), is closely linked to projections of human-caused warming several decades into the future. ECS measures the eventual surface temperature increase from such a doubling once ocean temperatures have fully adjusted. ECS largely determines TCR.
Define “largely”, provide a citationm or omit adverbs altogether.
Adverbs are not the auditors’ friend.
http://www.myworld2015.org/index.html?page=results
‘largely’…
This does not help clarify what is meant by “ECS largely determines TCR.”
Also note that the stakes behind this “largely” are not being disclosed.
Auditors might feel lukewarm about such nondisclosure.
largely
willard is largely a troll. Not completely, largely
Converse? No. Audit? To Steve like Kerry to Lavrov.
=============
Define largely.
For Willard ‘s benefit, not mine.
I kind of like Willard, He’s intelligent and witty in a nasty kind of way. I see him as the other side’s Kim, though he’s not nearly the writer Kim is.
The real troll around here is lollywot. I’m surprised more don’t see it.
This might not be the same usage than in “ECS largely determines TCR.”
Thank you for your concerns,
“This might not be the same usage than in “ECS largely determines TCR.”
Then again, it might be the same usage. lets say its largely the same usage.
To largely determine ain’t largely the same as to largely be.
willard
“To largely determine ain’t largely the same as to largely be”
who said it was?
go back to counting sentences.
> ECS largely determines TCR.
is the sentence in which”largely” should be clarified,
Thank you for playing.
willard
‘is the sentence in which”largely” should be clarified,”
drugs are bad willard, they destroy your ability to count or write grammatical questions.
But to answer your question.. check the posteriors.
Ok…
The Met Office Report tries to give weight to its erroneous conclusions about cause and effect — by dreaming up a chimera about warming in the later part of a warming period as providing some special signal about the part of the total warming caused by humans — and, sure enough, we’re all doomed.
So confident they were, they’ve carried no lifeboats.
==========
willard: Define “largely”, provide a citationm or omit adverbs altogether.
That’s it? The biggest error in the essay is that the word ‘largely” is insufficiently definite?
True, true considering GCMs are totally bullcrap — largely because the degrees of freedom are unknown — making validation is impossible.
> That’s it?
No.
Who *is* this willard person, I ask myself. …..who crawls through marshy weeds looking for bugs. ….when there is a bright sun shining. Isn’t there a bright sun shining? I wonder why he doesn’t want to notice.
….Lady in Red
He’s looking for an honest man under the streetlamp, because he lost his lantern back in the weeds.
===================
Such alarmist trolls can be amusing when not too tedious, but most readers ignore them. Now this little update on IPCC science will set the cat among the pigeons (nice going, Dr. Curry):
new David Rose article
Skiphil-
More and more I expect to see Alice and the Mad Hatter making an appearance. The reasoning becomes curiouser and curiouser
As pointed out by Armour et al., these short-term studies are likely to underestimate sensitivity because short-term responses don’t represent the full longer term response, being skewed by fast responding areas like the land and Arctic that have less water vapor feedback. In the longer term, Armour says that the warmer ocean feedback plays more of a role in the ECS. The models tend to have the tropical ocean responding too fast (hot spot issue), and the Arctic not enough (sea-ice overestimate).
I would also note that with a TCR of 1.6 C, the warming since 1950 is 100% accounted for by CO2, but that is just a corollary of Lewis’s number. The skeptics have come a long way in accepting these types of sensitivities and the fact of a significant positive feedback, and Lewis is helping them to see the light.
I don’t accept that there is a difference between TCR and ECR; then again I live on a rotating planet that is in an elliptical orbit around a star.
Its different by definition.
Lewis defined TCR as the response to a 1% per year CO2 increase of 70 years, which is a doubling over 70 years. I doubt this is the only definition of TCR, but this is not ECR, which is what you get if you run the model beyond that 70 years, at fixed CO2, until it stops warming. A more observationally based TCR would use that we have increased CO2 by 25% in the last 50 years at an accelerating rate.
From the Met report:
> TCR is defined as the mean change in global mean surface temperature at the time of doubling of atmospheric carbon dioxide (CO2) concentrations from pre-industrial levels, in a scenario of a cumulative 1% increase in CO2 per year. Hence TCR describes the change in global mean surface temperature in response to reaching a doubling of CO2. ECS describes the equilibrium response of the climate system, as defined by the global surface temperature reached eventually after stabilisation of atmospheric concentrations at a doubling of CO2.
Compare with the A’s description.
Does anyone know whether the ECS derived from models takes closer to 150 years or 400 years? I assume it varies from model to model. Also, is the assumption of a deep ocean layer that does not mix with the upper layer fixed into the models such that the ECS ignores the lower ocean? If this is the case, would not Trenberth’s hypothesis that the heat is going into the deep ocean, change the ECS and/or the time it took to get there? Nic? Mosh?
Modelers trying to keep their toys on circular tracks on the ceiling. Damn those bridges, the toys always fall when they get near water.
=========
The timeframe is also of significance. An ECR response of 2 degrees would be a very good thing if it arrived just in time to stop the next ice age.
For this to change, someone will have to show how the land temperature signal — which is closer to a representation of the eventual ECS — is deviating significantly from the projected average 3C warming per doubling of atmospheric CO2 based on the pre-industrial average.
webster, “For this to change, someone will have to show how the land temperature signal — which is closer to a representation of the eventual ECS — is deviating significantly from the projected average 3C warming per doubling of atmospheric CO2 based on the pre-industrial average.”
Bullshi$t. The models estimate “global” sensitivity when sensitivity is obviously regional. The models miss the tropics, miss the Antarctic, miss Arctic amplification and miss the mid-latitude land amplification. It is time for the models to “prove” they are useful.
You have serious denial issues.
Is it a comfort to you if the models are underestimating the land warming, or is it worse than you thought?
JimD,
These guys are comforted as long as it is ABCD.
The enduring hope that CO2 is benign and inert is like a Linus blanket to them.
JimD, “Is it a comfort to you if the models are underestimating the land warming, or is it worse than you thought?”
It is called a clue. If a model predicts one thing and another happens, you find out why.
Indeed, some aspects of climate change are faster than the models were predicting. Hopefully future models can do better otherwise no one will expect what is about to happen.
JimD, “Indeed, some aspects of climate change are faster than the models were predicting. Hopefully future models can do better otherwise no one will expect what is about to happen.”
As long as people expect 100% efficiency and attribution, they will be surprised.
No web,
we just have problems with folks who tell us the models can do more than they really can.
Although it is not an exact analogy, the similarity to traveling salesmen pushing a cure all tonic. The tonic isn’t useless – it will give you a nice buzz – but it doesn’t reduce swelling, improve eyesight, help grow hair and make it stand up all night.
GCM’s are a tool. One that has a rather narrow applicability. Making it reasonable to ask, Why are there 70 different versions of the same tool, considering the small number of uses? & Where us the evidence the tool performs as advertised?
This part is barely related to a model. It is simply correlating the land temperature change to the log of the CO2 increase.
Nic Lewis comes up with his number with a heavy weighting on the ocean, whereas groups such as BEST weight the land exclusively to estimate ECS.
The latter produces an ECS of 3C and the former gives a TCR of 2C.
For years the modelers have tried to keep their toys on circular tracks on the ceiling.
==============
Jim D,
“I would also note that with a TCR of 1.6 C, the warming since 1950 is 100% accounted for by CO2”
I suspect you don’t mean just CO2, but all GHGs. But the TCR value which is consistent with warming since 1950 depends on what you assume for the change in GHG forcing since 1950, as well as how much ocean heat accumulation was taking place in 1950.
If you consider the whole of the instrumental period, the temperature increase is about 0.8C and the forcing increase (absent aerosol offsets) about 3.1 Watts/M^2. If you accept the AR5 SOD best estimate for net aerosol offsets of 0.7 watt/M^2 and assume heat accumulation of ~0.6 watt/M^2, then the estimated ‘effective sensitivity’ (heat balance sense) is about 0.8/(3.1 – 0.7 – 0.6) = 0.444 degree per watt (~1.65 degree per doubling). The transient response would (of course) be considerably less than the effective sensitivity: (0.8/(3.1-0.7) = 0.333 degree per watt (~1.24 degrees TCR), and the equilibrium sensitivity a little higher. A transient response of 1.24C is not a particularly low value; Isaac Held seems to think is most likely near 1.3C.
You don’t need to know anything about aerosols or other GHGs to see the CO2 effect and compare it with the actual warming. At a 1.6 C TCR a rise from 310 ppm to 385 ppm (the average over the last decade) and a temperature rise of 0.5 C from 1950 to the last decade average, shows that these two numbers are the same. Yes, there are negative aerosol effects and positive effects due to other GHGs, but I am just looking at the CO2 attribution. Take away the CO2 effect, and you leave no warming. This is 100% attribution.
Jim D,
“You don’t need to know anything about aerosols or other GHGs to see the CO2 effect and compare it with the actual warming.”
.
Sorry, no. Radiation is fungible. You really do need to include a reasonable estimate for all significant forgings, or your analysis is not meaningful.
Paleo analysis is the means with which the slow feedbacks are estimated and how the long tails on the high side of ECS projections come about.
We simply do not have enough data from the modern-day observational records to estimate the slow feedbacks that occur over hundreds of years.
So, of course, if these are omitted, then the mean will reduce.
This is precisely why the closest corollary paleoclimate data needs to be used in combination with both the longest modern observations and the best models. The paleoclimate data will include all the feedbacks and full Earth system response to fill in the gaps of modern observations and model weaknesses. Lake El’gygytgyn in Siberia probably is our best single source for this paleoclimate data and confirms that major changes are ahead for the Arctic as CO2 goes over 400 ppm. Thinking about the Earth’s climate in mid-Pliocene terms is probably a good general analog if you want to see what the Earth system sensitivity is to doubling of CO2 from pre-industrial levels.
R. Gates, what do you think the trigger might be?
Abstract
2.8 Million Years of Arctic Climate Change from Lake El’gygytgyn, NE Russia
The reliability of Arctic climate predictions is currently hampered by insufficient knowledge of natural climate variability in the past. A sediment core from Lake El’gygytgyn in northeastern (NE) Russia provides a continuous, high-resolution record from the Arctic, spanning the past 2.8 million years. This core reveals numerous “super interglacials” during the Quaternary; for marine benthic isotope stages (MIS) 11c and 31, maximum summer temperatures and annual precipitation values are ~4° to 5°C and ~300 millimeters higher than those of MIS 1 and 5e. Climate simulations show that these extreme warm conditions are difficult to explain with greenhouse gas and astronomical forcing alone, implying the importance of amplifying feedbacks and far field influences. The timing of Arctic warming relative to West Antarctic Ice Sheet retreats implies strong interhemispheric climate connectivity.
http://www.sciencemag.org/content/337/6092/315.abstract
JimJam,
what evidence is there to demonstrate that reducing global GHG emissions would reduce the impact or delay the onset of a sever climate change, either to warmer or colder (but especially to colder)?
Matt Skaggs
“I would be interested to learn to what extent cloud feedback is now better constrained using up-to-date observational data than it was, say, ten years ago.”
I’m not sure it will fully answer your question, but there is an excellent, detailed discussion of clouds, their radiative effects, feedbacks and forcing in section 3 of the 2012 review paper “Observing and Modeling Earth’s Energy Flows” by Stevens and Schwartz. Available at http://www.bnl.gov/envsci/pubs/pdf/2012/BNL-96154-2012-JA.pdf
The Stevens and Schwartz paper also has an excellent section on aerosols. Regarding direct aerosol forcing (DARF), where estimates have come down over the last ten years – the AR5 best estimate is expected to be only -0.27 W/m2, down from -0.5 W/m2 in AR4, it concludes that ” it would not be surprising if the sum of the various contributions to the DARF is much closer to zero than previously thought”. And it concludes about aerosol indirect forcing (cloud adjustments): “the variety of ways in which clouds adjust to aerosol perturbations (Stevens and Feingold. 2009), many of which are not possible to account for given the relatively crude description of cloud processes in climate models, lends weight to the argument that, after a full accounting, the radiative forcing attributable to cloud adjustments to aerosol perturbations is likely to be small”.
Nic,
Thanks for the excellent post as well as this link to the Stevens and Schawartz paper for those who have not read it. This quote from that paper is particularly interesting, especially in light of discussions going on here about ocean heat content and TOA:
“Because the atmosphere has a relatively small heat capacity, an imbalance of energy flows at the TOA can be sustained only an increase in ocean enthalpy, augmented to lesser extent by melting of the cryosphere and warming of the land surface and the atmosphere.”
What this gets at, is that considering the relative sizes of energy storage, thermal inertia, and the importance of ocean to atmosphere energy flow for maintaining tropospheric temperatures, small alterations in that flow have big repercussions in tropospheric tempertures, and a better assessment of causes of those alterations is important if we really want to understand tropospheric sensitivity to longer term increases in GH gases. A more accurate measurement might well be total Earth system sensivity that captures energy increase related changes to the full system.
R.Gates, “A more accurate measurement might well be total Earth system sensivity that captures energy increase related changes to the full system.”
You have that already if you like. The average effective energy of the oceans is ~334.5 Wm-2 approximately equal to the estimated DWLR value. Increasing CO2 will increase DWLR within the limits of the specific heat capacity of the atmosphere warming the “average” of the oceans by roughly the same amount. That is 0.8C per 3.7 Wm-2 of additional DWLR. If the lower atmosphere cannot hold more energy, then there would be an increase in BDC, SSW events, deep convection, etc. etc. etc. until a new steady state is reached between the oceans and atmosphere.
We already have a fairly good estimate of the rate of ocean heat uptake ~0.8C per 300 years
captdallas:
“We already have a fairly good estimate of the rate of ocean heat uptake ~0.8C per 300 years”
Recovery from the LIA?
Would it be possible to recover from the LIA without the above increased OHC?
Ragnaar, “Would it be possible to recover from the LIA without the above increased OHC?” No, OHC and sea level would rise as the oceans recover the energy lost. Sea level rising has a better fit to a longer term recovery than CO2 forcing. OHC data is too short and too coarse to extend that far back, but since OHC and SST track well with sea level, tropical SST reconstructions can give you a good idea.
http://redneckphysics.blogspot.com/2013/05/how-to-splice-instrumental-data-to.html
Then since CO2 does actually have an impact, you can use it as a reference to estimate sensitivity to all forcing over a rational time scale.
http://redneckphysics.blogspot.com/2013/08/is-picture-worth-trillion-dollars.html
Without considering LIA depression, you get the ~1.6 C, If you think CO2 does it all, about 3.2 C, but if you allow for LIA depression, ~0.8 C. Which is remarkably close to Kimoto’s estimate of the Planck response once you include more current data.
http://edberry.com/SiteDocs/PDF/Climate/KimotoPaperReprint.pdf
captdallas:
I kind of followed that Kimoto paper, his approach his general point I think, but not so much the math.
I follow the 0.8 C in the Oceans over the last 300 years as the land temperatures aren’t going far without the permission of the Oceans.
Why isn’t this stuff simpler?
That 0.8 C is an ore boat load of energy though. 800 C in the atmosphere I think. Would you use 0.8/264 K to figure the percentage increase?
Ragnaar, “That 0.8 C is an ore boat load of energy though.”
Well, it is a planet. Kimoto has an interesting approach and other than the dF/dT~4F/T which gives some folks heartburn, pretty simple for a reasonable estimate. If that boat load of energy magically got transferred to the atmosphere it would have about a 1000 times impact, but it can’t.
I am not sure where you came up with the 264K, but there are a couple of ways to use the Kimoto simplification. The gross ratio is 4(F,r+Fe+Ft)/Ts using the Stephens budget estimates is 4(398+88+24)/289= 7.05 Wm-2/K which is how much the surface energy should change per degree.
That is the end of simple though because only part of that is due to back radiation, solar provides energy at the surface and in the atmosphere that is not going to be changed by atmospheric forcing that much. This is where the ocean and back radiation relationship comes in. Back radiation is ~340Wm-2 per 277K or 4(340)/277 = 4.9Wm-2 per K. Adding 3.7Wm-2 to the back radiation produces ~0.75 C of effective temperature change i.e. average temperature of the oceans increases. That takes 7.05Wm-2 per degree of surface energy to generate 4.9 Wm-2 of back radiation. So surface energy will need to increase by 7.05*(3.7/4.9)=5.35 Wm-2 to compensate for 3.7Wm-2 of atmospheric forcing. You might recognize the dT=5.35*ln(Ci/Co) as the “no feedback” climate sensitivity. Unless increasing latent cooling by about 1 Wm-2 triggers some major water vapor feedback, that is about all she wrote.
The 264K was my mistake.
“To find Kelvin, add 273 degrees to your Celsius value. So 15 degrees Celsius would be 288 Kelvin.”
So, 0.8/288 Kelvin.
0.27% increase using Kelvin for 300 years.
I am kind of following the back radiation add back used by Kimoto, that changes other parts of the equation.
Well, gee, I shoulda been more prompt at the Palace. The Met Office model builds in high sensitivity. Look what the Sorceror’s Apprentices have conjured.
================
So even in slightly dialing back their rhetoric against the “pause”, the MET’s still making every argument (and error) possible to keep the highest climate sensitivity possible. Well there’s a shocker.
Next thing you know, the revised summary for policy makers for the brand spanking new AR5 will argue that the pause, if it exists, is no evidence that AGW is any less C. Just like they have been told to.
“It’s worse than we thought, just not quite as fast as we though.”
CAGW is not science. It is made to order political PR.
WebHubTelescope
“Paleo analysis is the means with which the slow feedbacks are estimated and how the long tails on the high side of ECS projections come about.”
Not so. The long tails come about because uncertainty in the fractional change in forcing net of ocean heat uptake is large relative to uncertainty in the fractional change in global surface temperature. The fat long tails come about when improper statistical methods are used.
“We simply do not have enough data from the modern-day observational records to estimate the slow feedbacks that occur over hundreds of years.”
Simulations by AOGCMs with dynamic oceans can be used to estimate the difference between ECS as estimated from data spanning 100 years or so and the eventual ECS when the model is run until equilibrium is reached. The result of one such test was reported in Andrews et al 2012, running an AOGCM for ~6,000 years – a very computationally demanding simulation indeed. The two ECS figures were within 10% of each other.
Bad attempt at defending your arguments.
Some of the paleo studies have very broad density functions which means fat tails
http://www.skepticalscience.com/graphics/Climate_Sensitivity_500.jpg
Remove those and of course the ECS tends to a lower 3C value.
If we have both methods that have fat tails on the high side and methods that do not, the first group of methods is of little value in determining the likelihood of high values. The fat tails have existed, because every method has had fat tails, having even one reliable method without such a tail is enough to remove it.
Uncertainty of the denominator is a much more likely reason for a fat tail than uncertainties in the numerator, just as Nic wrote. One well known paper that has discussed this issue is that of Knutti and Hegerl (Nature Geoscience, 2008) (Fig. 2 in the article). They refer further to Roy and Baker (Science, 2007)
What the guy has to do is tell us what the mean values of the Paleo data set that he removed are. If the mean values of the paleo data set are 4C, then of course removing these will drop the resulting mean.
This is not that hard. The questions are not difficult and the answers are presumably not difficult.
Webby, Annan and Schmittner among others has lower paleo estimates, as I recall 2.3 and 1.7. I know this is the latest ploy, if models are wrong and they look very wrong, then data from 24000 years ago is better. And recent paleo estimates are also trending down.
What he has to do is tell us what the mean values of the data that he removed are:
http://www.skepticalscience.com/graphics/Climate_Sensitivity_500.jpg
Four traits of mediocre-to-weak skepticism:
• Purely statistical and/or quibbling and/or “cycle science” reasoning
• Sole authorship (as contrasted to Thurston-Polanyi science)
• Pronouced conservatism in regard to long-term conclusions
• Unilaterality of conclusions (with implication of conspiracy)
Nic Lewis is smart enough to recognize this his various writings show all four traits of weak skepticism … so why does he take no steps to remediate any of them?
Strong science *gains* from strong skepticism! Please *strengthen* your skepticism in the above four respects, Nic Lewis@
Fan, please pardon any typos, as my eyes are so full of tears of laughter that I can hardly see straight.
You do realize that none of your points apply here, right? Let’s go through your points:
1. Nic’s comments are based on physical measurements. It’s the Met that has gotten it wrong — and wrong twice: once because of disregard for physical evidence, and once because of misunderstandings of the data.
2. You did notice that Nic was mainly expanding upon Otto, et al, right. You do know what “et al” means?
3. Science determines what science will determine. Being “conservative” or “enthusiastic” (or whatever you’d call it) in your conclusions has nothing to do with science. You do know what “science” means?
4. I missed the part where Nic talks about a conspiracy. Please help me find it. Or perhaps that word doesn’t mean what you think it means?
It is a pleasure to enlighten you, Wayne!
(1) Climate measurement without transport physics == “cycle science” (which is weak)
(2) None of Nic Lewis’ former collaborators affirmed his present conclusions.
(3) Conservatism enters when the implications of science are considered (individually and/or organizationally); this largely determines whether the relevant time-scales are annual (as in business), decadal (as in politics), or generational (as for ordinary humans).
(4) When Nic Lewis finds 12 flaws in a MET report, and all 12 flaws apply same-sign corrections to the climate-sensitivity, then with probability P<1/2048 we an infer either that (A) The Met Office is conspiring to slant the analysis, or (B) Nic Lewis is cherry-picking his critique to support a predetermined (but unconscious) denialist rejection of high-end climate-sensitivity.
Question Which is more nearly true, Climate Etc readers: Met Office conspiracy or denialist rejection-by-cherry-picking of high-end climate-sensitivity?
Remark It is a pleasure to bring you the gift of laughter, Wayne, by asking these questions!
“the relevant time-scales are annual (as in business), decadal (as in politics), or generational (as for ordinary humans)”
You do realize that you are either very stupid or insane don’t you?
Politics runs on a ‘decadal’ time-scale!
‘Ordinary humans’ operate on a generational time-scale?
More nuts than Brazil.
Point (4) is decisive–unless Fan can show that Nic has missed OTHER mistakes by the MET that point in the other direction, we can assume that the MET non-conspiratorially slanted their findings to make their own model look good and maintain policy consistency with Urgent Mitigationism. Thanks, Fan!
Stupid and/or insane folks and/or brainwashed cult members seldom are cognizant of their plight, eh DocMartyn?
That’s why its reassuring to assess the quality of my company.
Whereas the company of the ABCD opposition is unpalatable!
That’s common sense, eh DocMartyn?
Would (4) be more decisive if there were 13 flaws?
How about 8?
Counting flaws seem to matter, then.
They are merely trying to keep their model in the mix a bit longer until they can modify it and publish a new, improved version.
A fan of *MORE* discourse: Nic Lewis is smart enough to recognize this his various writings show all four traits of weak skepticism … so why does he take no steps to remediate any of them?
So, …, today’s essay was an instance of “weak skepticism”! THE FAN HAS Spoken! Let us all think on that. An instance of “weak skepticism”!
Yes, the fan is into “Strong Trolling” to combat what he calls weak skepticism, but he’s a little weak on his calculations himself, as we have seen. Seems unable to calculate 7 x 40. His “weak calculation”? 400. LOL.
> The Met Office Report considers whether climate model estimates of TCR and ECS need to be revised in the light of recent observational evidence, in particular the relatively slow increase in global surface temperature over the last 15 to 20 years. It concludes that, broadly, such estimates – and hence climate model projections of future warming – do not need to be reduced.
Was there other observations to than the global surface temperatures?
“Relatively low” according to whom, the Met or the A?
“Broadly” according to whom, the Met or the A?
What were the arguments that warranted the Met Office to reach such conclusion?
Quoting the main conclusions one wishes to criticize may follow the best practices.
> Barely half CMIP5 models analysed (Forster et al. 2013) have TCRs below the 95% upper bound for TCR of 2.0°C given in Otto et al, using observational data for the latest decade.
Could this “Barely” be replaced by “more than”?
What role does this fact qualified by yet another adverb play in the alledged contradiction?
willard (@nevaudit) | September 14, 2013 at 4:18 pm | Reply
> Barely half CMIP5 models analysed (Forster et al. 2013) have TCRs below the 95% upper bound for TCR of 2.0°C given in Otto et al, using observational data for the latest decade.
Could this “Barely” be replaced by “more than”?
———————————————————————
Glad you asked. Of course it can be replaced but it would sacrifice information in the act. “More than half” could be any number between 50% and 100%. “Barely half” tells us that the number is very close to 50%. If you had the verbal skills you think you do you wouldn’t have asked such a stupid question.
> “More than half” could be any number between 50% and 100%.
Sure, if it was 99% you’d still use “more than half”, right?
The word “half” carries enough information in both expressions, Big Dave. The main information that carries the “barely” is that half is not a lot for the A of an op-ed. This appears to be an evaluation void of any objective criteria. An unnecessary subjective judgement in something some may claim is a technical analysis.
Imagine that.
Jim D
” As pointed out by Armour et al., these short-term studies are likely to underestimate sensitivity because short-term responses don’t represent the full longer term response, being skewed by fast responding areas like the land and Arctic that have less water vapor feedback. In the longer term, Armour says that the warmer ocean feedback plays more of a role in the ECS.”
IMO the Armour paper is suspect. It is based around a particular AOGCM that has a latitudinal pattern of climate feedbacks that is substantially different from those exhibited by most AOGCMs. The Andrews et al 2012 paper’s findings support the view that the Armour paper is mistaken. Indeed, it is now routine to estimate ECS for AOGCMs from what you call the short-term. At 100-150 years, the period involved it is long enough to activate all but very long term feedbacks, and appears to be sufficient to get a fairly accurate approximation to equilibrium sensitivity.
“I would also note that with a TCR of 1.6 C, the warming since 1950 is 100% accounted for by CO2, but that is just a corollary of Lewis’s number.”
I don’t think a TCR of 1.6 C is my number, if that is what you are saying.
Armour et al. offer a mechanistic explanation of why sensitivities based on a few decades always will underestimate actual ECRs if there are fast-response components in the climate system. Land and Arctic areas are currently warming at twice the global average rate, which I would say rates as a fast-response component of the type Armour was talking about. The Otto et al. work acknowledged Armour’s paper and they clearly were aware of this limitation of their own assumptions.
On the other point, if you use 1.4 C for TCR, the CO2 rise alone accounts for 90% of the warming, still comfortably in the “most” range of the IPCC’s very likely most statement in AR4. I only mention this because many here seem to doubt even that statement.
I decided that you were making stuff up, but didn’t want to make an accusation without substantiation.
So I plotted the SH and NH temperatures of land and ocean, from 1971 to 2012.
Then I took the slopes.
The Southern Hemisphere land is warming at 50% the Northern Hemisphere land.
The Southern Hemisphere SST is warming at 30% the Northern Hemisphere land.
The Northern Hemisphere SST is warming at 50% the Northern Hemisphere land.
You talk utter tosh
http://i179.photobucket.com/albums/w318/DocMartyn/HemisphericTemperatures_zps3c6b1073.png
Doc Martyn’s
As the Northern hemisphere temperature, SST and sea level change bears no relation to its Southern hemisphere equivalent, you do wonder what the purpose is in coming up with a composite Global average which bears no relation to any of it’s constituent parts.
Tonyb
DocM, try this. What ratio do you get for the land and ocean warming rates?
http://www.woodfortrees.org/plot/crutem4vgl/from:1970/mean:120/plot/hadsst3gl/from:1970/mean:120
CRUTEM (land) and HADSST (ocean) go into HADCRU (global).
The difference in surface temps above land and ocean is the result of a lack of water availability over land. If it warms at all this should reduce over time with more evaporation over oceans and rainfall over land. The oceans drive land temperatures and will drive land temperatures down.
e.g. http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2778.1
CH, the lack of water availability is exacerbated by the growing temperature differential between land and ocean. Less relative humidity is less clouds is less rain is drier soil is more warming. A positive feedback of sorts.
A warmer world is always wetter. More water falling on land increases the water availability. A negative feedback to land temperature aye Jim?
Land temperatures are driven by ocean temps.
e.g. e.g. http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2778.1
I think the modelers would be surprised with falling RH.
Tonyb, almost 1.
http://www.woodfortrees.org/plot/hadcrut4sh/from:1970/mean:120/plot/hadsst2sh/from:1970/mean:120
Odd isn’t it that ‘Global Warning’ is only present on the top northern part of the globe.
DocMartyn,
It is pretty clear that warming in the norther hemisphere is greater than the southern because most of the aerosol emissions and large aerosol cooling effects are in the northern hemisphere….. um, no, wait…… never mind.
SteveF, “It is pretty clear that warming in the norther hemisphere is greater than the southern because most of the aerosol emissions and large aerosol cooling effects are in the northern hemisphere….. um, no, wait…… never mind.”
Yes, Smartsols. I think there is a knob on most of the models for those.
Think, people, the NH land masses are much larger while the ocean is 90% of the SH. It stands to reason the SH land is dominated by the ocean, while the NH land has large interiors far from the ocean. These are the areas that warm fastest too. The more poleward areas in the NH also are affected by Arctic warming. Taken together the NH and SH land warmed more than twice as much as the global ocean in the last few decades, as I showed.
CH, a warmer world would be wetter in equilibrium when the RH returns, but we are in a transient state with faster land than ocean warming. As you may know, a cooler ocean than land is not conducive to land humidity, which is why the summer is less cloudy than the winter over land.
The land is not actually warming faster than the ocean. Land temperatures are driven by the oceans.
http://s1114.photobucket.com/user/Chief_Hydrologist/media/DIETMARDOMMENGET_zps939fe12e.png.html?sort=3&o=18
‘A characteristic feature of global warming is the land–sea contrast, with stronger warming over land than over oceans. Recent studies find that this land–sea contrast also exists in equilibrium global change scenarios, and it is caused by differences in the availability of surface moisture over land and oceans. In this study it is illustrated that this land–sea contrast exists also on interannual time scales and that the ocean–land interaction is strongly asymmetric. The land surface temperature is more sensitive to the oceans than the oceans are to the land surface temperature, which is related to the processes causing the land–sea contrast in global warming scenarios. It suggests that the ocean’s natural variability and change is leading to variability and change with enhanced magnitudes over the continents, causing much of the longer-time-scale (decadal) global-scale continental climate variability. Model simulations illustrate that continental warming due to anthropogenic forcing (e.g., the warming at the end of the last century or future climate change scenarios) is mostly (80%–90%) indirectly forced by the contemporaneous ocean warming, not directly by local radiative forcing.‘
The difference is caused by differences in water availability – which are less in a warmer world.
RH by the way remains fairly constant – it not exactly so. Transition – smansition. There is always lots of moisture around – not limited at all over oceans – and warmer air holds more water. A physical fact aye Jim?
CH, you can look at the graph I posted above and say the land is not warming faster than the ocean? How does that work?
Didn’t you just say that? There is differential that is caused by less water availability over land – something that changes. It is not a terribly interesting or significant factor.
Just remember that the RWP and MWP and LIA were NOT global. Only NH. Therefore they can be ignored. The melting of Arctic sea ice (-2.5% per decade for Winter Max.) and the warming of NH today however is a clear sign of GLOBAL warming. Got that?
Chief Hydrologist | September 14, 2013 at 9:22 pm |
“The land is not actually warming faster than the ocean. Land temperatures are driven by the oceans.”
Incorrect. Land is warming faster than ocean. Land temperatures are moderated by the ocean not driven by it. The moderation effect was named “continentality” in the 19th century when some astute individuals noticed that seasonal temperature change was larger the farther inland one was from the ocean.
Jim D | September 14, 2013 at 8:27 pm |
“Think, people, the NH land masses are much larger while the ocean is 90% of the SH.”
You’re the one that needs to do some thinking and it needs to be preceded by fact checking. Land is 30% of the earth’s surface. There is twice as much land surface in NH vs. SH. Therefore 20% of the earth’s land surface is NH and 10% in SH. But SH is 50% of total surface area so land occupies 20% (not 10%) of the southern hemisphere and 40% of the northern hemisphere.
Did you actually look at the study Jabberwock or are you just pulling it out of your arse as usual.
http://s1114.photobucket.com/user/Chief_Hydrologist/media/DIETMARDOMMENGET_zps939fe12e.png.html?sort=3&o=18
The difference in temperature is the result of difference in water availability – and therefore of lapse rates. Water availability changes. The temperature in an ocean dominated world – ‘the big kahuna’ – is maintained indirectly by ocean heat content.
Nic its also interesting to note that most of the models get polar amplification all WRONG.
The degree of wrongness is pretty stunning. What is more odd is that they underestimate the ice loss.
Something is fundamentally wrong
Steven Mosher, “Something is fundamentally wrong”
I am shocked! Shocked I tell ya. Probably has nothing to do with water though :)
“Something is fundamentally wrong”
Gee, ya think?
Blood & water.
John 19:34 But one of the soldiers with a spear pierced his side, and forthwith came there out blood and water.
Understand
Got the kidney, eh?
=========
Nicholas Lewis “Independent climate scientist” ?
What does this mean? Is there some sort of qualification implied here? Some examination to be passed? Or, can anyone, even people like Wagathon, describe themselves in like fashion?
Used to be called in days of yore, a “gentleman scientist.” Someone without formal affiliation with academic institution or government. Charles Darwin was a gentleman scientist for most of his life I believe.
Wikipedia lists a bunch of independent scientists, including James Lovelock and Peter Mitchell who won a Nobel Prize in chemistry… despite what were regarded at the time as radical ideas,,, for which he likely would not have been able to get funding through the usual channels.
Peter was part of the Tarmac family, and married up.
He and his brother put the money up to buy the house in Bodmin and turn it into a research institute. He had worked in conventional academia, but had funding problems.
Peter hated reviewers; no imagination. He published his work via the vanity press; the Gray book and the Blue book.
He also had gold ear-rings, just like a pirates.
James Lovelock. Of Gaia fame? I think we should leave him out of it. Peter Mitchell looks to have followed a conventional academic pathway. C Darwin was born in 1809 when science was in its infancy. Is Nic Lewis being compared to him?
I’m sure NL must have some credentials. Uni degrees, work experience etc. Have I just missed seeing what they are, or is he reluctant to say?
As Steve McIntyre shows, you don’t need to know anything about climate to do statistics. You get a hold of the data somehow, maybe just asking around or doing FOIAs, and just treat it like numbers. You don’t have to know what the numbers mean.
McIntyre has been published, more than once. He found Hansen’s mistake on Y2K, and Hansen’s colleague acknowledged McIntyre and thanked him. It was important because they actually had to change a claim about the warmest year on record. McIntyre demolished the Hockey Stick. He figured very prominently in the Climategate emails, and that wasn’t because he didn’t have a clue; it was because he did have a clue and they were afraid of him. He’s not getting any dumber as time goes on either.
Don’t kid yourself – he knows what the numbers mean.
That was one brand of a hockey stick. It was a Northland hockey stick, which I don’t think are made anymore. Now you have Reebok, Easton, Bauer, CCM etc.
Lots of hockey sticks left to demolish, eh ?
“It was important because they actually had to change a claim about the warmest year on record.”
Not that nonsense. Educate yourself.
http://logicalscience.blogspot.co.uk/2007/08/james-hansen-on-1934-y2k-bug-one-of.html
Those old hockey sticks, like the wood Northlands, were easy to break, eh.
These newer ones are all like carbon fiber you know, eh.
Just ask that Canadian hoser McIntyre, eh.
I’m not sure how much climate science SM knows. You think it isn’t much at all? You could be right. But, I’m asking for info on NL. He does claim to be a climate scientist. Is this a lifelong interest of his? If he is being compared to Charles Darwin I should point out that he was always genuinely interested in biology. He didn’t take up the study to bolster a particular preconception. Can NL say the same?
Nic Lewis is an accredited IPCC expert reviewer.
Bashing him is therefore bashing the IPCC.
Thanks for once again demonstrating your proficiency and propensity in cranial gluteus inclusion.
You could be right about SM? But what about NL?
What do you want to know.
Climate sensitivity is given by a well known formula.
There are observations which can be input into this formula
Calculating the answer requires math skills.
Temp,
this is the best you can do? Criticize Nick for being a ” gentleman scientist” ?
Rather ungentlemanly of you.
timg56,
I don’t know about ‘gentleman’. That’s immaterial anyway. If there’s any implied criticism its the other way around. I’m suggesting he’s not a climate scientist.
Temp,
There is nothing magical about a climate scientist. Every one of the moderators at SkS is not a climate scientist. Yet that site gets referred to so often one might think it the bible of climate science. The chief reference book at least.
Look around and you find all sorts of non climate scientist actors in this drama. Peter Gleick? Lewandowski? An NGO of your choosing? How many contributors to the IPCC reports have/had ties to enviro groups?
Statistical analysis does not belong solely in the realm of climate science. If you have followed the debates, you might think it barely exists in that realm at all, based on the apparent lack of quality.
If you want to believe that Mann, Marchot and Gergis are superior SA practitioners’ to McIntrye and Lewis (among others) go ahead.
With the scare quotes that ‘climate science’ has assiduously earned, we are well on the way to trusting non echo-chambered critiques instead, by scientists from other realms, or ‘rooms’, not captured and dependent upon the ’cause’.
=================
Play the arguments – not the man.
Nic Lewis’s argument, or claim, is that he’s a climate scientist. My argument is that he isn’t until he shows some evidence to support that claim.
Heh,heh, it seems his science is better than that of 17 climatologists combined. None dare call it climate science.
=============
Webby, Willard, Fan et. al.
You only weaken your asserted position(s) by posting such as above.
Why not address the substantive points Mr. Lewis, that Dr. Curry chose to post, made about MET misrepresentations. Present alternative facts, or (just for grins), an alternative physics explanation to his negative lapse rate feedback expanation posted above. So far, you whimper in objection.
Assuming, of course, that you understand how GCMs actually work. if you don’t, try reading the imminently accessible technical documentation to GCM NCAR CAM3. It is free online at NCAR/TN-464+STR(2004). a simple Google will get you there. And, it is free!
Then get back here about whether GCMs can now (or ever) model micro phenomena on a macro scale, as required for Nics negative lapse rate feedback, the impossibility of which was admitted by AR5 WG1 SOD 7.2.1.2. (Leaked, so we will see if it stands or gets modified by posts such as these.).
On such a scientific post thread, one desirable requirement is to know or learn a minimum about the science being discussed. Opinions, beliefs, world views, empathies, and such count for ZERO in such situations. Just generally accepted fundamental facts (you know, like here the Clausius-Clapeyron equation of AR5 WG1 SOD (leaked) Chapter 2.5.6.) Plus additional data, and maybe even additional theory, as both Nic and I ( in comments)posted above on this thread.
Just state your alternative theories and experiments with error bounds, and supporting alternative math. That would be really interesting to discuss, but I am guessing the sounds of silence will result.
Sir Rud,
Thank you for your kind words.
Do you happen to know how many representations from the Met the A of this op-ed has enumerated?
Can you list them?
Many thanks!
Oh, and not responding might be interpreted as a lack of reading skills by sharp Denizens such as your very humble self.
Willard,
see above. It’s 42. Or 56. Depending on whose count you want to go by.
Psst, I wouldn’t put much faith in 56. The rigor with which that number was arrived at was on par with the question it was purported to answer
Sir Rud,
What often happens when a student writes an incomprehensible answer to a scientific exam question is that the teacher simply puts a large red X on the page.
He or she doesn’t always have the time or inclination to deconstruct what was going through the student’s mind when they wrote their answer.
You should always take this into consideration when someone does not follow-up to some gibberish that has been spewed.
WebHubTelescope (@whut) | September 15, 2013 at 10:22 am |
“What often happens when a student writes an incomprehensible answer to a scientific exam question is that the teacher simply puts a large red X on the page.”
Sounds like experience talking and since you were never a science teacher we can reliably infer where your experience lies…
Has your foot ever left your mouth even briefly?
From my own university experience, the toughest job is to grade assignments, lab reports, and exams. You want to give the students a fair shake by putting the effort into trying to interpret what they mean , but then you realize that to deconstruct each wrong answer is like another assignment on its own. So you do the best that you can, knowing that the students are really there to learn and have invested their money.
On the other hand, message board trolls like Springer deserve little empathy, and they can be roundly debunked or ignored, take your pick.
Remember, this is what Rud said:
> It’s 42. Or 56. Depending on whose count you want to go by.
Well and good, Tim. It’s not the number that counts, but how the answer gets justified.
So please quote some.
Search for “mislead” if you need help.
The most likely future for climate-change ain’t complicated Rud Istvan.
During the next ten years, increasingly sophisticated GCMs will agree with increasingly complete paleoclimate data to increasing accuracy. Meanwhile increasingly accurate global thermometry, gravimetry, and altimetry (ARGO/GRACE/JASON) will affirm Hansen-type global energy imbalance predictions with increasing accuracy. As an overall result, the GCMs, paleoclimate record, and energy-balance observations will all evolve into increasing perfect accord.
During the same coming decade, the world;s denialist cohort will cherry-pick, quibble, spin, and slogan-shout with unabated fervor. And yet (for good common-sense reasons) fewer-and-fewer citizens will pay any attention to the increasingly desperate denialists.
Conclusion It’s game over, man, game over! … and Hansen’s worldview wins.
Rud Istvan, now do you appreciate the strategy by which James Hansen (and his scientific colleagues) have been playing the climate-change chess-game, to win … with forty years on their time-clock?
Thank you for providing this clarification, Rud Istvan!
Finally, the presence of vigorous climate variability presents significant challenges to near-term climate prediction (25, 26),
leaving open the possibility of steady or even declining global mean surface temperatures over the next several decades that could present a significant empirical obstacle to the implementation of policies directed at reducing greenhouse gas emissions (27). However, global warming could likewise suddenly and
without any ostensive cause accelerate due to internal variability. To paraphrase C. S. Lewis, the climate system appears wild, and may continue to hold many surprises if pressed. http://deepeco.ucsd.edu/~george/publications/09_long-term_variability.pdf
Ever considered you might be wrong FOMBS? And the likely trajectory for climate – since the 1998/2001 climate – is cooling fro decades more? No – I don’t suppose so.
Chief, your arch-skeptical views would be enjoying considerable scientific credibility today, if during 1998-present sea-level rise had reversed, and also global energy imbalance had reversed, and also polar ice-mass loss had reversed.
But none of those reverals happened. When are we going to see these reversals? And why should we believe your decadal predictions of future reverses, when your decadal retrodictions of past reverses are dismally wrong?
Well I might just repost this from the open thread.
Here is ocean heat from a 2013 paper by Lyman and Johnson paper?
http://s1114.photobucket.com/user/Chief_Hydrologist/media/oceanheat_zps2cb4a7a1.png.html?sort=3&o=1
It shows slow ocean warming until the mid 1990′s – a peak in 2003 – a decline and then a slow rise in the ARGO period. The rise in ARGO is consistent with a decrease in reflected SW in CERES.
e.g. http://s1114.photobucket.com/user/Chief_Hydrologist/media/CERES-BAMS-2008-with-trend-lines1.gif.html?sort=3&o=125
Straddling the 2 periods – pre and post 1998/2001 – is difficult in both energy flux and ocean heat data. Different instruments and little in the way of intercalibration. A world of difference in data gathering.
However, the 1998/2001 climate shift is captured.
http://s1114.photobucket.com/user/Chief_Hydrologist/media/ProjectEarthshine-albedo_zps87fc3b7f.png.html?sort=3&o=0
‘Earthshine changes in albedo shown in blue, ISCCP-FD shown in black and CERES in red. A climatologically significant change before CERES followed by a long period of insignificant change.’
Palle and Laken (2013) provide us with a proxy with TOA radiant flux – clouds are net cooling – linking the earlier and the later datasets with tropical SST.
http://s1114.photobucket.com/user/Chief_Hydrologist/media/cloud_palleandlaken2013_zps3c92a9fc.png.html?sort=3&o=23
It shows minimum cloud at the end of the century – a shift after – and a modest decrease in cloud captured by CERES in less reflected SW. All pretty consistent? It should be.
Fan could improve the climate on this blog by disappearing.
Rud,
I have downloaded this some time ago. Do you mind if I make a comment?
This model is of extreme complexity, although many of the components are based in fairly conventional mathematics.. I have dealt with far simpler models in a different domain and it would take me months, if not years, to understand this model mathematically. I would have to do a vast amount of research to understand the basic physics that is incorporated in this model, let alone to the depth at which I could criticise it meaningfully. The oint I am making is that this is a Herculean task for non-specialists.
Therefore, is there any way that a non-specialist can engage with these models. The only way is to examine their outputs, which is a more basic scientific approach. I agree that this is fraught with difficulties but it is an approach that can be undertaken by people with a more general background in statistics and signal processing.
Thus there are three levels of scepticism. The first is highly specialised that can engage with the basic implementation of the models, the second is the criticism (very important IMO) of specifc aspects of the modelling of the physical processes and the third is comparison of outputs and observations. I would suggest that most non-specialised, people with a scientific background fall into the latter.,
All these are valid lines of criticism? Yes they all are and they all contribute to uncertainty of model prediction, but the third is probably more compelling for the majority, particularly for policy makers.
RC Saumarez
You don’t need to be able to build a computer model of an automobile based on first principles to have an excellent practical understanding of automotive technologies. The same goes for climate.
RC, you draw very good distinctions about levels of understanding. Certainly, comparison of model to actual is the simplest and most accessible to all. My concern is that certain important phenomena here negative lapse rate feedback, aka the adaptive iris hypothesis, inherently cannot be modeled in any GCM in the foreseeable future due to computing power limitations. Why then, do we spend so much money trying? And why does the IPCC put so much faith in the modeled results?
AR5 SOD 7.2.4.4 literally says cloud feedback is positive. “This conclusion is reached by considering a plausible range for unknown contributions by processes yet to be accounted for, in addition to those occurring in the climate models.”
That is cargo cult science.
@Dave Springer,
I go along with your analogy up to a point. However, if you are trying to build a formula 1 racing car, which is as ambitious as GCMs, you can either say that this car won’t work properly because the parameters of the suspension damping system is wrong … or that it is a lousy car because lots of different drivers have failed to get it to perform.
The distinction is that if one analyses the car computer model, one may see that either the car is fixable or that it cannot be fixed because its design is totally flawed. This is useful information. If one simply discards the car, someone else can come with a different design and try it, although it contains the same flaws, because they hadn’t analysed why the earlier design doesn’t work.
This is the problem with GCMs. Nobody knows, corrrect me if I am wrong, whether the difference between results and prediction are due to some fairly simple and analysable oversight or whether GCMs are completely flwed because they are incapable of modelling climate with a feasible amount of computing power, their solutions are chaotic or the physics model is just plain wrong. This is quite an important distinction because if it can be shown that climate models are intrinsically flawed, as opposed to being wrong in one small detail, it directs thought into other, and possibly more productive, avenues.
RC
CMIP5 ensemble is clearly running too hot. You are correct that no one knows for sure where or in how many places the ensemble is flawed. The mere fact that an ensemble is used instead of a single model shows that no single model is deemed trustworthy. The hope in using an esemble is the error or errors will average out i.e. you’ll get a result that’s a little wrong all the time instead of spectacularly wrong some of the time. The expected result of ensembling materialized as expected and over the course of 22 years the small error all-the-time gradually ran the projected temperature outside the 95% confidence bound when compared to measured temperature. Notably the measured temperature is lower than expected which makes the skeptics and their back of the envelope calculations the intellectual giants.
Fascinating –
Notice how not one “skeptic” catches Rud’s attention as being so inferior to him so as to be unqualified to comment on this thread. And yet, Rud says:
<blockquote Opinions, beliefs, world views, empathies, and such count for ZERO in such situations.
So that must mean that Rud’s failure to notice any “skeptics” that reach his elevated level of viewpoint must be purely coincidence, and not at all related to his “opinions, beliefs, world views, or empthies,” – or otherwise Rud would not have added that comment to this thread.
Well, either that are all the “skeptics” here understand GCM’s at levels as lofty as Rud’s understanding and (presumably for that reason) agree with his interpretation of their validity.
Remember, Rud, selective reasoning is selective.
You really are a stupid and bilious troll. Not everyone who is sceptical can engage in the fine detail of CGMs but many of us are capable of comparing their predictions with measurement.
All your ad-hominem attacks alter nothing. You, Willard and discourteous fan add absoultely nothing of substance to this thread.
They are a fine measure of the cognitive dissonance of the alarmists. I don’t want to enjoy the screams; that would be schadenfreude.
=======================
It is interesting, RC, that in your response to my comment, you failed to address the substance of my critique.
Rud selectively found some commenters here not meeting with his elevated status of being knowledgeable to comment about GCMs.
Why do you suppose that is?
Or maybe calling me names addresses that point? If so, maybe you could dumb the explanation behind that logic down enough that I might be able to understand it, you know, with me being stupid and all.
(BTW – we might also look at the selectivity in your observations about biliousness. Pretty ironic given the contrast of the tone of your post, don’t you think?)
Oh,and BTW, RC –
Thank you for that immeasurably valuable contribution to this thread.
There’s a decline curve in that value, declining with experience. That input is critical to understanding for the newbies, declining steadily for the veterans.
============
Joshua | September 15, 2013 at 9:33 am |
“It is interesting, RC, that in your response to my comment, you failed to address the substance of my critique.”
Your critique had no substance. It never does. You are a science illiterate posting on a science blog. Willard is in the same boat. You both try to be relevant but all you do is annoy others and make fools of yourselves. That in my opinion is your first best reason for remaining anonymous cowards.
Here’s what’s interesting about that, David. You repeat the same opinion over and over even though it is completely illogical to begin with, and at least in my case not only proven wrong but also – when challenged to put some money behind that opinion – you instead chose to go running away with your tail between your legs.
It really takes a special kind of person to persist under such circumstances, David, and you are exactly that kind of special person.
Pingback: Nic Lewis’ response will hit Met Office like a boomerang « De staat van het klimaat
This all seems intolerably naive – post and comments alike.
Models are unable to predict anything – they are chaotic. There are many feasible solutions. At most a perturbed physics model can produce a probability distribution of future climate states. This is shown schematically here.
http://rsta.royalsocietypublishing.org/content/369/1956/4751/F8.expansion.html
Moreover the physics of actual climate states can not be modeled at all with precision greater than tossing a coin. That climate shifts occur at decadal frequencies seems to put an impossible burden on expectations of precise – or even imprecise – forecasting.
Therefore – the only senible answer for climate sensitivity is …. wait for it… γ in the linked diagram.
http://s1114.photobucket.com/user/Chief_Hydrologist/media/Ghil_fig11_zpse58189d9.png.html?sort=3&o=0
http://www.atmos.ucla.edu/tcd/PREPRINTS/Math_clim-Taipei-M_Ghil_vf.pdf
Now we need 1000′s of times more computing power to find out what the question is.
Sensitivity is more correctly sensitivity to initial conditions and can indeed be negative or positive at different times depending on the distance to a bifurcation point, the direction of approach and the nature of the resultant instability.
‘The climate system has jumped from one mode of operation to another in the past. We are trying to understand how the earth’s climate system is engineered, so we can understand what it takes to trigger mode switches. Until we do, we cannot make good predictions about future climate change… Over the last several hundred thousand years, climate change has come mainly in discrete jumps that appear to be related to changes in the mode of thermohaline circulation.’ http://www.earth.columbia.edu/articles/view/2246
Although THC seems significant in large scale shifts – there are of course other shifts that have been less persistent and long lived in the modern era. These seem related to ocean and atmospheric patterns associated with cloud changes that – from the data – seem the dominant forcing in the satellite era by far.
‘What happened in the years 1976/77 and 1998/99 in the Pacific was so unusual that scientists spoke of abrupt climate changes. They referred to a sudden warming of the tropical Pacific in the mid-1970s and rapid cooling in the late 1990s. Both events turned the world’s climate topsy-turvy and are clearly reflected in the average temperature of Earth.’ http://www.sciencedaily.com/releases/2013/08/130822105042.htm
Chief Hydrologist | September 14, 2013 at 6:20 pm | Reply
“Moreover the physics of actual climate states can not be modeled at all with precision greater than tossing a coin.”
Nonsense. Physics explains why the temperture of Venus is warmer than Earth and why Earth is warmer than Mars. Physics also explains why land surface temperature is more variable than SST. Physics explains the seasons, ocean currents, atmospheric circulation, and a whole raft of other phenomenon. Your continual harping on chaotic boundary conditions is tedious, irrelevant, and defeatist.
“The winds change the ocean currents which in turn affect the climate. In our study, we were able to identify and realistically reproduce the key processes for the two abrupt climate shifts,” says Prof. Latif. “We have taken a major step forward in terms of short-term climate forecasting, especially with regard to the development of global warming. However, we are still miles away from any reliable answers to the question whether the coming winter in Germany will be rather warm or cold.” Prof. Latif cautions against too much optimism regarding short-term regional climate predictions: “Since the reliability of those predictions is still at about 50%, you might as well flip a coin.” http://www.sciencedaily.com/releases/2013/08/130822105042.htm
Is anyone predicting that winter in Germany will be warmer than summer?
Summer being warmer than winter is climate. One winter being slightly warmer or colder than another is weather. Weather is contained within aforementioned chaotic boundary conditions. Climate is not.
What happened in the years 1976/77 and 1998/99 in the Pacific was so unusual that scientists spoke of abrupt climate changes. They referred to a sudden warming of the tropical Pacific in the mid-1970s and rapid cooling in the late 1990s. Both events turned the world’s climate topsy-turvy and are clearly reflected in the average temperature of Earth.
Changes in means and variance in the time series is chaos Jarhead the Jabberwock.
Your essay makes some outstanding points Nic Lewis!
• Conservative skeptics like Nic Lewis argue that “cloud feedbacks are highly uncertain.”
• Conservative scientists like James Hansen agree with Nic Lewis that “the error bar on the derived sensitivity is necessarily large,” and that tuning model parameters to fit paleoclimate data yields the conclusion “burning all fossil fuels would make much of the planet uninhabitable by humans.”
• Conservative historians like Naomi Oreskes agree with Nic Lewis and James Hansen and Wendell Berry that “scientists-in-committee are far too short-sighted in assessing that long-term implications of these findings.”
• Conservative citizens like Wendell Berry agree with Nic Lewis and James Hansen and Naomi Oreskes that “we are talking with practical urgency about obvious needs.”
• Conservative religious leaders like Pope Francis agree with Nic Lewis and James Hansen and Naomi Oreskes and Wendell Berry that “We have fallen into the hypocrisy of the priest and the levite; [we say] “it’s not our responsibility”, and with that we feel reassured, assuaged.”
Needless to say, to the above list could be added innumerable conservative military leaders (Samuel Locklear!), conservative politicians (Ronald Reagan!), and conservative businesses (Exxon-Mobile!).
Conclusion Thank you Nic Lewis — and James Hansen and Naomi Oreskes and Wendell Berry and Pope Francis and Samuel Locklear and Ronald Reagan — for adding your diverse conservative voices to chorus of conservative voices in science, history, religion, the military, politics, business, and most of all, plain ordinary conservative citizens!
Nic Lewis, it is good that you recognize that among the greatest long-term threats to the maturation and prospering of *true* conservatism is the willful ignorance, cherry-picking, faux-science, statistical quibbling, and selfish short-sightedness that constitute the foundations of climate-change denialism!
It’s nice to see climate skeptics accept the IPCC statement that over half the warming since 1950 is caused by human greenhouse gas emissions?
For that IS what your figures show isn’t it Nic Lewis?
We’ve come a long way from denial that man causes is causing global warming haven’t we?
Also our skeptic friends might like to take a look at figure 2. Look at the numbers on the Y axis and compare them to climate variability in the holocene. Yep that’s a hockey stick blade you are looking at.
To reiterate, surely the big news here is that climate skeptics are beginning to accept man, not nature, dominates global temperature change in the modern era. These figures are closer to what the IPCC has been saying all along rather than the “global warming is a hoax” james inhofe-style denial.
It’s amusing to see climate skeptics trying to spin these developments backwards. As if they’ve been telling us to expect 2C+ warming from human greenhouse gas emissions all along!
Iolwot
Half WHAT warming since 1950?http://www.metoffice.gov.uk/hadobs/hadcet/
tonyb
http://www.metoffice.gov.uk/hadobs/hadcrut4/diagnostics.html
Iolwot
Thanks for posting a very nice graphic of the ‘pause’ that you are always denying. But ‘global’ warming Isn’t Global is it?
http://www.metoffice.gov.uk/hadobs/hadcet/
tonyb
Would you say global population increase isn’t global?http://tinyurl.com/nj2ynlv
lolwot,
Humm… I don’t know what ‘skeptics’ you have been talking to, but I have always said that adding GHG MUST raise the average surface temperature. (People who claim GHG driven warming is either non-existent or trivial are not really skeptics, they are simply misinformed, in the same way that people who claim GM soybeans are dangerous to your health are misinformed.) The argument has always been about how much warming there will be in response to GHG forcing, and that argument continues. I have said for at least several years that the likely ECS is in the range of 1.8C-2C per doubling of CO2, and 1.2C to 1.3C for transient response (near the low end of the IPCC range). What I have consistently argued is that 3.2C (model ensemble mean) or 4.5C or more (some individual models) for ECS and 1.6C to 2.0C for transient response are simply not consistent with the observational data. The magnitude, rate, and most of all, down-stream consequences of GHG driven warming all depend on the sensitivity to GHG forcing, so prudent public policy on GHG emissions depends critically on reasonably accurate sensitivity values.. The disagreement is mainly about sensitivity, and not too much else.
Fan is going offside by falling back on the paleo data. The UM team’s response to McIntyre’s comprehensive destruction of the paleo reconstructions is that the paleo data aren’t relevant, we believe in UM based on fundamental physics, or the GCMs and don’t need no stinking ice-cores or tree-rings. Get with the party line, Fan!
stevefitzpatrick
I disagree with you last sentence. I suggest the disagreement is also about the damage function.
And it should also be about the probability that the policy solutions advocated by warmists will deliver the benefits that warmists claim.
Gosh stevefitzpatrick, you just plain forgot to consider the longer term paleo-data!
The paleo indicates that longer-term climate sensitivity plausibly is *far* higher than shorter-term observational data can unveil even in principle … isn’t that right?
That’s the common-sense reason why ignoring the paleo-data amounts to a willfully ignorant form of climate-change denialism!
It is a pleasure to broaden your temporal scientific horizons stevefitzpatrick!
Yeah, Steve, haven’t you noticed that after CO2 goes up, the temperature always goes down? It’s all very plain in the paleo record.
=====================
Thank you Kim, for reminding us all to respect the reasoned discourse of science and reject the ideology-driven demagoguery of denialism!
That was well done, Kim!
I don’t think I get it.
===============
One skeptic responds “what warming?”
The other responds “what skeptics?”
Avoiding the issue that this post confirms the IPCC statement of attribution.
You know the statement that denizens of this blog have been forever gnashing their teeth over.
Catastophic global warming is an ideologically inspired narrative which is being rapidly disproven by observation.
The big news is that actual climate response is trumping hysterical narratives and mainstream climate scientists are beginning to accept the idea of a lesser beneficial anthropogenic global warming instead of the hyperbolic visions of drowning in a rapidly rising ocean.
Thanks for playing. There’s a consolation prize waiting as you exit stage left. It’s an autographed copy of “An Inconvenient Truth”. The autograph however is by Richard Lindzen and the inscription is “Bullshiit!”
Lolwot
I see just the opposite. The establishment is having to admit there is a pause and based on very recent papers here, they are admitting to less sensitivity and a bigger role for natural variability. It will be more clear with the IPCC release. What I find fascinating is the great psychological investment by many warmists and their inability to even entertain the thought they might be wrong. It reminds me of some fund managers on Wall Street who are so enamored by their superior intellect that they refuse to believe they could have made a bad investment and they ride their position all the way to zero. And then Poof!
The priests are moving on, leaving the useful idiots stranded in the pews.
================
The moving priest preaches; and, having narrated, Moves on.
From Otto & Al 2013:
> The best estimate of TCR based on observations of the most recent decade is 1.3 °C (0.9–2.0 °C; dark red, Fig. 1b). This is lower than estimates derived from data of the 1990s (1.6 °C (0.9–3.1 °C); yellow, Fig. 1b) or for the 1970–2009 period as a whole (1.4 °C (0.7–2.5 °C); grey, Fig. 1b.
Some mediation might be needed.
Perhaps this was not clear enough. From the Met Report:
The emphasized sentence is still true if we correct the 1.4 in Figure 1 to 1.3. In other words, this error does not lead to any misrepresentation that has been spelled out in the A’s memorandum.
***
The mediation that is needed is about the claim that “the best estimate of TCR based on observations of the most recent decade is 1.3 °C”, which has been said to be, in Otto & a lii 2013:
http://www.nature.com/ngeo/journal/v6/n6/full/ngeo1836.html
for reasons we’ll turn to below.
One thing that is amazing about the long pause in global warming is the evidence that, for example, “CRUTem3 has overstated U.S. warming trends during 1973-2011 by at least 50%.”
This is how I see it. Most anthro. heating is in the northern hemisphere. The southern hemisphere temperature is mostly influenced by the surface tenperature of the oceans. One of the unknown unknowns is the delay of the S hemisphere catching up with the N hrmisphere’s rising temperature. The 1910 – 1940 temperature rise seemed to disappear sharply after 1940, but it did not. It produced the first ‘pause’ in history starting in 1948 and extending to 1970. Now the S hemisphere resists temperature change for two reasons: First, because water is a poor conductor of heat, so heat transport depends on Coriolis at depth and wind and haline density induced slow currants. This is not an inertial delay but a true transport delay. This difference is vital in climate models, but is largely unknown as a parameter But the southern oceans’ huge heat storage means it will be slow to change – say at a guess about 30 years. My thesis is that the global temperature rise between 1970 and 1998 was just the second installment of the 0.5C atmospheric rise between 1910 and 1940. See my website underlined above.Of coarse the IPCC missed all this because it mostly confined its investigatiohs to post-1961..
The difference between EcS and TCS, discussed at some length above by Nic, is this largely unknown transport delay which may be, at a guess, about 30 years. It may not even be a constant, we just don’t know what the currents are at the bottom of the oceans. Until this is better known the ECS will always be in doubt.
Well, ECS is a concept ripe for conjecture, if not frankly imaginary. Equilibrium never occurs, and even were it to occur, the path there is unknown. Similarly, though less fabulously, TCS may never be separated conclusively from the turbulence of chaotic nature.
And, as previously demonstrated over and over again, any warming man can generate from the apparently low sensitivity being shown over and over again, will be beneficial in net.
=======================
Waiting for the mediation that the “it’s 1.4, no it’s 1.3” conversation the A might have with the Met, let’s follow our reading of the op-ed. Here are the sentences from the 7th paragraph that contain adverbs that would deserve due diligence:
Consensus? What consensus?
Not only likely but very nearly egregious the wrongness of the model, eh?
====================
The IPCC has just applied for membership in the lukewarmer tribe.
I think it may be time to delineate a new consensus…
Accepting applications for the ‘Lukewarming Cooler’ clan. Hurry, the line is getting long.
==========
Well, fan, your ‘heads up’ bit is accelerating.
====================
Which show that Naomi Oreskes is entirely correct: the IPCC’s large-committee style of science is far too conservative to keep up with accelerating climate-change realities that everyone can see
Thanks for the heads-up, Steven Mosher!
+(-1)^0.5
If Naomi Oreskes is correct, it is most likely by accident and assuredly not entirely.
All the evidence indicates that your head is always up.
Propriety prevents me from saying what your head is always up but here’s a clue. If your feet were in California and your shoulders in New York your head would be up your Kansas.
hey fan if you want to join the other anti scientific folks who deny the new consensus, be my guest.
Let’s all welcome the IPCC. Nice Job Dr. Curry!
Walking backwards.
Searching for heat.
Fear gathers.
We have nothing to travest but our travesties.
======================
Divesty thee of the travestesy,
Saith the Lord
I first read the Met Office report in an earlier thread and I thought at the time that the Met Office was emulating many sceptics by placing too much credence on short term data.
The defensive posture of the paper seemed to reflect a perceived need to reinforce their position on AGW and that their consistent advice to the UK government that CO2 emissions needed to be drastically reduced was justified.
The pause IMO does not preclude further spikes in the global warming metric but neither does it preclude a continuation of the pause or even further cooling resulting from the DPO and the likely dominance of La Nina’s over the next few decades.
Consequently, the paper by Nic Lewis, is probably also falling into the same logical position as for many AGW supporters and for many sceptics, by accepting the premise that the current pause in the global warming metric is of significance, statistically or otherwise.
The AGW Union of Secular, Socialist Researchers have nothing left but for a city somewhere to simply bust into flames and burn to the ground (like a modern day Sodom and Gomorrah) as a result of the flipping of the switch on the final incandescent bulb that sets off thermageddon.
Already happened, thermageddon. Great Lakes area, 1871 – October, of all times! For a rural thermageddon, Victoria, Australia, 1851. People blamed comets, someone’s cow etc for Chicago-Peshtigo. It was, of course, our old mate the climate. Never been nice, the climate. More snips and snail and puppy dog tails than sugar ‘n spice. Climate’s a boy.
A plea to those clever people who say they can manipulate the climate through processing trillions in Other People’s Money in weird ways. If you really can perform this magic…
Please don’t dial us back to the 1930s! What with North America and Australia parching to dust, and China half washed away, I just don’t think I could take it. Choose some normal, stable era like…like…you know, like…um…
I’ll have to get back to you on that one.
Wagathon, er isn’t that how religious narratives usually end up?
A thundebolt sent from space ter punish the wicked. :(
Jest – a – wicked – serf.
Was it written down?
Wagathon, please appreciate that gibes about “cities in flames” are morally regrettable in view of the emerging appreciation of (what appears to be) China’s brush with heat-death catastrophe,
FAN what would it take to make you decide the world had entered a cooling phase. A dip in global temperatures for how long?
If it just goes back to zero anomaly for 2 months or 2 years?
Forget ice mass at the poles, that Relies on a wonky algorithm that keeps being changed every time the sea ice extends out at the South Pole and has massive error margins.
Don’t know if they can do it up north being sea ice and not on land and being thus even more unreliable.
They have PIOMASS but it is even more wonky and is going up a little?
Draw a line in the sand for me, if you acknowledge having one.
angech, you ask: “FAN what would it take to make you decide the world had entered a cooling phase?” The answer is “Nothing.” The Fanster would’nt be able to be a funster if he gave up the belief basis on which he can yank people’s chains. Get a button-flush toilet, no more exposure to yanking.
angech, please be aware that Chief has already asked that question … and the answer is simple:
That’s the simple reason why, according to the predictions of (what Judith Curry calls) “the best available science”, The most likely future for climate-change ain’t complicated.
LOL … It turned out that the conservative luminaries Nic Lewis and James Hansen and Naomi Oreskes and Wendell Berry and Pope Francis and Adm. Samuel Locklear and the ghost of Ronald Reagan had all booked appointments ahead of me … they were depressed by the stupidity and futility of denialism.
These conservative luminaries all got the same prescription: that foolishly short-sighted & willfully ignorant climate-change denialism would go extinct on its own!
I am sure it was a different question I asked.
Finally, the presence of vigorous climate variability presents significant challenges to near-term climate prediction (25, 26),
leaving open the possibility of steady or even declining global mean surface temperatures over the next several decades that could present a significant empirical obstacle to the implementation of policies directed at reducing greenhouse gas emissions (27). However, global warming could likewise suddenly and
without any ostensive cause accelerate due to internal variability. To paraphrase C. S. Lewis, the climate system appears wild, and may continue to hold many surprises if pressed. http://deepeco.ucsd.edu/~george/publications/09_long-term_variability.pdf
Ever considered you might be wrong FOMBS? And the likely trajectory for climate – since the 1998/2001 climate – is cooling fro decades more? No – I don’t suppose so.
Let me dare answer for Fan.
Sea level is rising.
Ocean heat content is rising.
There is no statistically significant pause in surface warming.
The world is therefore warming.
Get back to me when these metrics change. I won’t hold my breath. At the rate GHG levels are rising due to human emissions if anything these metrics will accelerate.
“The world is therefore warming.”
True.
“The dose makes the poison.”
Also true. The ‘details’, like how fast the Earth is warming, really do matter. Maybe you could stop restating the obvious and focus on the more important issue of how fast.
Well, the dose of warming since the Little Ice Age seems like vitamins to a malnourished person.
================
“There is no statistically significant pause in surface warming”
?
There is either a pause or there is not a pause — unless you are speaking in Trenberthian — and, statistics is irrelevant. For example, for a pause in elevation gain, you need a level not a probability table.
The reply has been delivered. And angech has fallen silent.
Why is this, the world wonders?
Is it … the bankruptcy of denialism?
angech lives in Australia and has fallen asleep not silent.
The question [unanswered, I like that] remains“FAN what would it take to make you decide the world had entered a cooling phase.”
Not some rubbish about the past and 1998 . The future. What values would make you decide on a cooling phase.
Simple
Easy
Values [Mathematical]
It figures.
I’ll give my answer to the same question, but it may sound repetitive to my posts on the pause, but here goes.
The appearance of any trend on any of the major published data sets that is negative and excludes zero, for example if the trend calculated on the Skeptical Science trend calculator for GISS was -0.115 +/- 0.0114 C per decade, I would say we have entered a cooling period.
Since I have no idea what role the eight chapter plays in the overall economy of the A’s argument, I’ll skip it for now and will read the ninth:
I have emphasize the adverbs, but what matters in that paragraph is the Met claim purported to be contentious: “none of these methods can be said to be superior to the others”. Let’s compare that excerpt from the Met report, which we can find at the beginning of section 3:
The A omitted to mention the reason behind Met’s claim. Neither has the A mentioned why this reason would be contentious. Nor has he shown how this “standard to test the validity of theoretical models by comparing their predictions to observational data” can evaluate estimates obtained via different assumptions.
In fact, the conclusion presented with the adverb accordingly, purely, and likely should be more direct than that. If we accept that comparing predictions to observational data is the litmus test, then it follows quite immediately that observational models should win.
If our argument is correct, the the A has hidden an a priori argument behind weasel words which makes it look empirical.
Reality is always good. I plotted the Norther/Southern hemispheric temperature anomalies vs Log[CO2], for the 1982-2012 period, knowing that 30 years is ‘climate’ and not weather.
http://i179.photobucket.com/albums/w318/DocMartyn/hemispherictempvslogCO21982-2012_zps736f33bb.png
Now from the slope we can directly derive the CS to [CO2], assuming all temperature changes, on average, are due to [CO2].
Loc slope CS
CRU4-SHL 7.70 2.32
CRU4-NHL 19.87 5.98
HADSST2-SH 4.95 1.49
HADSST2-NH 9.71 2.92
This gives an average ‘global’ sensitivity of 2.9 degrees per 2x[CO2], using area of the different locals.
Now the magic,
if as the Met says only half the heating is due to CO2, then this falls by half. If ECS is 1.5 TCS, then the answer to the ‘global’ ECS is 2.16.
One does not simply choose uncertain data over a well-defined map on the way to Mirror.
We simply don’t know which weapon will slay the uncertainty monster.
It may be wiser to throw everything we got at this wicked problem than pussyfoot for a bunch of cheap op-eds.
I thank and congratulate Nic Lewis for his excellent contribution and for continuing to discuss his work with commenters on Climate Etc. and elsewhere.
Two thoughts occurred to me as I read this post:
1. It seems that skeptics from outside climate science have uncovered the major problems with the orthodoxy – e.g. Steve McIntyre and Nic Lewis. Why is this, given we are paying so much money to climate science organisations to do good science?
2. The BOM repeatedly selected or changed figures to make sensitivity higher and projected temperature in 2100 higher. How can this happen if scientists are not being biased and negligent?
#2……..It can’t
This is one of the questions in climate science that is no mystery.
What matters at this point of time is that finally somebody (the “Daily Mail”) has published a photo of Dr. JC that I like.
http://www.dailymail.co.uk/news/article-2420783/Global-warming-just-HALF-said-Worlds-climate-scientists-admit-computers-got-effects-greenhouse-gases-wrong.html
More junk from the Daily Mail I see. David Rose doubling down on his errors and Judith Curry joining him.
Take this for example:
“She said it therefore made no sense that the IPCC was claiming that its confidence in its forecasts and conclusions has increased.
For example, in the new report, the IPCC says it is ‘extremely likely’ – 95 per cent certain – that human influence caused more than half the temperature rises from 1951 to 2010, up from ‘very confident’ – 90 per cent certain – in 2007.
Prof Curry said: ‘This is incomprehensible to me’ – adding that the IPCC projections are ‘overconfident’, especially given the report’s admitted areas of doubt.”
How can Curry justify this when this very post by Nic Lewis (which the Daily Mail even reports on!) presents figures that back up the IPCC attribution statement?
I in particular reacted to this claim by Rose:
“Back then, it said that the planet was warming at a rate of 0.2C every decade – a figure it claimed was in line with the forecasts made by computer climate models.
But the new report says the true figure since 1951 has been only 0.12C per decade – a rate far below even the lowest computer prediction.”
The figure 0.2 C referred to projected future changes, not historical ones. (Se AR4 SPM, section “Projections of Future Changes in Climate “).
Yes, there’s been no point at which warming has been 0.2C/decade since 1950. For hadcrut4 I get:
1950 to 1990: 0.04C/decade
1950 to 1998: 0.07C/decade
1950 to 2000: 0.08C/decade
1950 to present: 0.011C/decade
I let him off though because like you say he probably just got confused over the predictions rather than the historical trends.
Note, lolwot, how the trends accentuate the present pause, and confound the predictions.
==================
I agree. The color of her eyes goes very well with the blue sky in the background. Her eye color is indicative of highly evolved perspicacity. Not surprisingly my eyes are exactly the same steel blue color. :-)
=======
Oops, that comment was a quart low.
=====
“ECS largely determines TCR.”
With no further assumptions about the time constants involved it is not the case. The only thing we know (provided there is no overshoot in response) is that TCR can’t exceed ECS and can’t be negative.
It puts the ratio TCR:ECS in the [0,1] range, but that’s all.
Therefore the general form of response function with all time constants specified is of primary importance. Without that a small TCR is fully consistent with a large ECS.
Please note ECS has no relevance to policies whatsoever if full equilibration time is centuries or millennia. We do know for sure a runaway warming is impossible because of the strongly negative Stefan–Boltzmann feedback (and also because of climate paleohistory).
What politicians may be concerned about is the maximum possible rate of warming on decadal scales and that seems to be severely limited by the long response time of oceans.
Berényi Péter | September 15, 2013 at 4:42 am | Reply
“With no further assumptions about the time constants involved it is not the case. The only thing we know (provided there is no overshoot in response) is that TCR can’t exceed ECS and can’t be negative.”
A pendulum does not swing provided there is no overshoot.
Overshoot is very common in dynamic systems and it almost certainly exists in many forms in the climate system.
I posted this yesterday afternoon, but did not get a reply from R. Gates. Let me try again.
Jim Cripwell | September 14, 2013 at 4:40 pm |
R.Gates, you write “or we’ll have returned to the dark ages ruled by wacko right-wing nutters who will teach that the Earth is only 7000 years old.”
By that I take it to mean you equate me with people who believe the world is only 7000 years old. I sort of resent that. I have stated over and over again, that I rely on empirical data, and empirical data only. There is ample empirical data on what the true age of the earth is. So how you can equate me with such an erroneous idea, I have no idea.
The little empirical data that we have, gives a strong indication that the climate sensitivity of CO2 is indistinguishable from zero. Now if you can produce some empirical data which shows that this is wrong, I would,be grateful. ALL the numbers associated with the climate sensitivity of CO2 are either estimates and not measurements, since we cannot do controlled experiments on the earth’s atmopshere; or they are things like paleo data, where there is no proof that the alleged rise in temperature was, in fact, caused by the rise in CO2 levels, and not the other way around.
Do you have any measured, empirical data to prove that I am wrong?
To explain half the 0.6C warming since 1950, transient climate sensitivity would have to be no greater than 0.81C per doubling of CO2.
According to figure 2 above, only Otto 2013 1970-2009 (which we are told not to use!) barely covers this range.
Figure 2 therefore suggests it is very likely that climate sensitivity is greater than 0.81C per doubling of CO2.
In other words we could say “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations”
Hmm where have we heard that before?
So why is it that so many denizens and even our hostess have attacked the the IPCC attribution statement?
Can we have an apology for wasting everyone’s time, wrongly giving people the impression that the IPCC attribution statement is too certain, and a statement that the IPCC attribution statement is, if anything, too conservative?
Lolwat so a statistically significant pause in global warming is how long. 50 years? 100 years ?
Come on be brave
Maybe FAN could tag team with you . You could answer his temp question with an actual figure and he could answer your idea of a significant pause. Don’t be shy.
Any length. Show me that there’s been any length of pause. 2 years. 3 years. Good luck though, the climate is noisy. Current data is consistent with warming continuing.
Iolwot
Is this not evidence of a pause? You posted it yourself just yesterday.
http://www.metoffice.gov.uk/hadobs/hadcrut4/diagnostics.html
tonyb
There are no trends shown on that graph.
Iolwot
Its YOUR graph. Follow the blue line
tonyb
The blue line is not a trend. And notice the dashes at the end.
Lolwot-
It doesnt take more insightfulness than a 5th grader to answer the question of “what is the blue line showing at the far right end of the graph?” No trend you say? We will see. The only thing I have in all these debates is the data. And I understand how to read a simple graph.
iolwot
As it says in the explanation the dashes reflect the uncertainties in the endpoint. You dont need to draw a trend line Follow the line with your eyes. Is it up, down or static?
tonyb
Lolwat Will this do ? From today’s Australian “According to The Daily Mail, the IPCC draft report recognized the global warming “pause”, with average temperatures not showing any statistically significant increase since 1997
Thats 16 years a lot more than 2 or 3.
Thanks for playing.
You want me to believe the Australian’s interpretation of the Daily Mail’s interpretation of the IPCC draft report?
You have to be kidding me.
Time for a tricolor flag analogy,
Red for a statistically significant warming trend, for example 0.2 +/- 0.1 C per decade.
Yellow for a warming trend that is not statistically significant, say 0.1 +/- 0.15 C per decade.
Green for a trend that is between -0.05 and + 0.05 C per decade with uncertainty small enough that you are 95% certain the trend is within those bounds.
People are looking for simple answers to complicated questions. Trend value, trend length and uncertainty all have to be considered to determine if the answer to the question of is it warming or not.
Short term trends usually have high uncertainties and thus finding statistical significance is harder.
Trick question of course but don’t let it scare you . Just put a time frame on a significant pause.
Please?
Anyone game?
angech, please be aware that Chief Hydrologist has already asked that question … and the answer is simple:
That’s the simple reason why, according to the common-sense predictions of (what Judith Curry calls) “the best available science”, the likely future for climate-change ain’t complicated.
Angech
A pause is unusual, but by no means unprecedented at lower levels of co2
http://judithcurry.com/2013/06/26/noticeable-climate-change/
To have two decadal pauses in a row with co2 rising strongly would be highly unusual so my guess would be that there will be a significant change upwards or downwards, rather than maintain the stats quo.
Bearing in mind the temperatures have been increasing for 350 years, if that step was decisively down wards against the backdrop of rising co2 I think that would cause widespread confusion in the climate community
tonyb
“
In scienceIn all human endeavour, it is standard to test the validity of theoretical models by comparing their predictions to observational data. ”Fixed that for ya! Science doesn’t have a monopoly on lucid thought ya know.
“The strong negative lapse rate feedback is very closely linked to the water vapour feedback (they are sometimes combined into a single feedback) and has a similar level of understanding.”
That’s what I’ve been saying. DWLIR doesn’t warm the ocean basin significantly. It drives evaporation in a 10um surface film where it is effectively completely absorbed. The DWLIR energy is instantly made latent. The greater evaporation rate reduces the lapse rate. Clouds condense higher in the atmosphere where they have a less restricted radiative path to space and a more restricted path radiative path back to the ocean surface. The result is a wash. Ocean heat content (OHC) is increasing from warmer runoff from the continents where the GHG effect works as advertised to raise surface temperature. By that path it does not necessarily enter the oceanic mixed layer as much of it is colder than the ocean mixed layer and it simply follows the continental shelf into deep water along the bottom. It’s colder than the mixed layer because much of GHG warming is in higher latitudes in the winter when the surface is frozen resulting in winter beginning later and ending earlier.
WebHubTelescope (@whut) | September 14, 2013 at 4:30 pm |
It’s the ocean, stupid. Its albedo is close to zero. It is warmed by shortwave which penetrates hundreds of feet at the speed of light. The warming at depth by shortwave radiation cannot escape radiatively as the ocean is almost perfectly opaque to longwave. Thus the thermal energy at depth imparted by shortwave solar energy must be mechanically transported to the surface before it can escape. This is exactly the mode of operation that atmospheric greenhouse gases exhibit – transparent to shortwave and opaque to longwave. The difference is the ocean has thousands of times the heat capacity of the atmosphere. Just the top 10 meters of the ocean water has more thermal mass than the entire atmosphere above it.
In other words deep bodies of water are uber greenhouse fluids. The earth is warmer than the moon because of its oceans not its wispy atmosphere. The primary role of the atmosphere isn’t trapping heat it’s establishing a surface pressure so that liquid water can exist in a 100C temperature range enabling a liquid ocean in the first place.
Thanks for asking. I realize I don’t represent all skeptics but don’t say no skeptics can explain why the earth is warmer than the moon without the aid of greenhouse gases because I’m a skeptic and I just explained it.
You haven’t explained it. You’ve forgotten that we are measuring the temperature at the surface.
The Earth only absorbs about 240wm-2 from the Sun. Yet the surface emits about 390wm-2.
Your mechanism cannot explain that. The difference has to be decided in the space between the surface we are measuring and space (ie it’s something in the atmosphere – GHGs specifically).
Not the ocean which is underneath the site of measurement and so irrelevant. To look at it another way: your mechanism cannot cause a 240wm-2 absorption to produce a 15C surface temperature.
Ocean surface temperature where most of the solar energy enters the system (the tropics) is about 30C so your explanation of how 240W/m2 average insolation cannot make the surface warmer than 15C is easily disproven. Because the warm tropical water is less dense it spreads away from the equator towards the poles remaining on the surface as it goes warming the atmosphere along the way mostly through evaporation and condensation. For the most part rain warms the troposphere. Write that down.
SpringyBoy, For your theory to work, an expanse of ocean would need to deviate from a smooth Planck profile to one that shows notches in IR bands.
As it stands, the upper layer of water is so dense that it scatters ALL infrared radiation equally, thus leading to the smooth Planck response. And a smooth Planck response will not do what you want it to do.
Your problem is that you are a bully, and you think the lack of responses by well-qualified physicists allows you to run wild with your ill-thought-out theories. Well, the reason you don’t find responses is that these guys have better things to do with their time, and they don’t have an interest like I do in Voodoo Science and their kwack practitioners.
Not even close to a smooth Planck response at the surface, dummy. Get a clue. Start here:
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/chapter05_06.htm
Show me the radiative spectrum of a liquid water object. If it deviates from the smooth Planck response, I may reconsider your argument.
Once again, I get the feeling that you are trying to walk back what you originally claimed.
Read this short bit here , which is a concise explanation of how the wavelength notches provided by GHG raise the temperature of the surface above the 255C predicted by a black body.
http://climate.gsfc.nasa.gov/static/cahalan/Radiation/EarthRadVblackbody.html
Since the notches are there, the radiating source temperature has to increase to compensate.
You can play around with this via David Archer’s online Modtran simulator
http://forecast.uchicago.edu/Projects/modtran2.html
First, try the defaults at 70 km, looking down
Notice the notches in the spectrum. Those are due to GHGs
Next, set the altitude at 0.1 km, looking down
Note how close it looks to the black-body spectrum.
SpringyBoy, your theory (aka liquid GHG) that the ocean differs from a black-body radiator is so bizarre and far removed from anything known in the research literature that it places you into the ranks of the kooks and krankpots.
Pekka, “Air pressure does affect thermodynamics in many ways, but not dramatically.”
I think you are missing what I am saying. C-C is based on a surface temperature that has nothing to do with the temperature of the air becoming saturated at 2250 to 3000 meters. The saturated and mixed phase surface at that altitude is what is needed to determine the saturation pressure of that air. If you are using CC with a surface temperature you have to be assuming that there is a fixed lapse rate and CC does not deal well with supersaturation. The atmosphere above the atmospheric boundary layer is not well mixed, CC is not going to be accurate across the atmospheric boundary layer, it should predict too little water vapor and too little convection.
A better way is to consider the ABL as the “surface” then to determine the heat capacity you need to consider the local temperature and pressure/altitude. Then at sea level, 26.5 C & saturation you have ~80 joules per grams dry air while at 2250 meters, 26.5 C saturation you have ~105 joules per gram dry air due to the difference in specific volume. I used 26.5 C because that is considered the convective triggering potential.
WHUT
Again, go here:
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/chapter05_06.htm
If Planck response were smooth on the ocean surface then SST would not vary by longitude along the same latitude line over the ocean. It inarguably does vary. The reason it varies, despite TSI being equal at the same latitude and well mixed CO2 is that evaporation and condensation varies and that in turn changes the vertical temperature distribution. Evaporation and condensation insensibly transports energy from the ocean surface and deposits it high up in the atmosphere.
Furthermore, you might have missed the memo that “global warming” is now happening in the ocean below the mixed layer with no Planck response at all on the surface. How’s that work, dopey?
Springer, keep on walking it back.
You were the one that claimed that the ocean was a :”liquid GHG”.
David, Webster will never get that and Pekka is liable to descend upon you for saying pressure is a factor in how much water air can hold for a given temperature.
“In the beginning, Hansen created the 33C, and all was radiance and light.”
Cappy Dick, You have said in the past that the number is much larger than 33C and that the lapse rate feedback reduces the number.
Redneck on that.
Webster, “Cappy Dick, You have said in the past that the number is much larger than 33C and that the lapse rate feedback reduces the number.”
That was Manabe that said that, but he never said how much IIRC. One estimate was about 90C which would include the surface warming to atmospheric cooling range since the tropopause is considerably colder than 255K degrees.
As far as the value of the 33C, it is pretty limited because it assumes constant albedo, constant albedo ratio, land to atmosphere and ignores latent heat transfer. It is one of those “if all things remain equal” kind of things.
But things don’t remain equal do they?
If you consider latent and sensible surface energy, the total “average” surface energy is 398+88+25 = 510 Wm-2 at a temperature of ~289K degrees. At 240Wm-2 and 255K the difference is (510-240)/(289-255) = 270/34 or 7.97 Wm-2/K instead of (390-240)/(288-255)=150/33=4,54 Wm-2/K There is a pretty big difference if you consider latent and sensible using current estimates.
lolwot – in fact I did explain it. You not agreeing with the explanation does not negate the fact that I offered an explanation.
dallas – I made no mention of how much water the atmosphere will hold vs. pressure. I said that without atmospheric pressure there could be no liquid ocean. That is a statement of fact as at 0 millibars water does not have a stable liquid phase.
David, So you are going to avoid Pekka by sticking to extremes?
So “offering an explanation” is all you need to do to get a scientific degree or a job at a research institution?
What world does Springer live on?
Ahhh, yes, the world where Intelligent Design is an appropriate answer to any question put forward.
So the game that Springer is playing is that you get 1 point if you offer an explanation and 0 points if you don’t. Springer will either win every time this game is played, because most of us will say “don’t know” at some point.
WebHubTelescope (@WHUT) | September 15, 2013 at 10:47 am |
“does not negate the fact that I offered an explanation”
So “offering an explanation” is all you need to do to get a scientific degree or a job at a research institution?
———————————————————————–
Straw man. You’re qualified to keeps crows out of cornfields. I’m not sure for what else but that job is a slam dunk for you.
dallas
How is it being extreme to say that the most important climate function of the atmosphere is providing an environment wherein a liquid ocean can exist? I consider that a simple of fact and calling it “extreme” makes no sense to me at all.
WebHubTelescope (@WHUT) | September 15, 2013 at 10:47 am |
Not just any explanation. It doesnb’t have to be a scientifically correct explanation but rather a politically correct explanation and then you’re in like Flint provided it agrees with the politics of the institution in question.
Thanks for asking. If I can assist you again in the future don’t hesitate to beg for help.
Politically correct explanations do not help when you try to apply that science to a technology. You can’t engineer a product to work based on a political explanation for some scientific phenomenon.
Similarly, Springer’s idea that a sphere of water (enclosed by a transparent film and inside a vacuum to set up a boundary condition) will increase temperature beyond that expected for a black body (when irradiated by light until it reaches a steady state) is not correct.
The problem with any of these explanations is that there are an infinite number of them. And just because you have one doesn’t make you special.
David, because water exists in all three phases. If the pressure is low enough it can only exist as a solid or a gas. Earth is in the unique position where water can exist up to 100C and down to -18C at the surface thanks to salt and down to -40C in the atmosphere thanks to super saturation. Picking 0 mb kind of trivializes things.
CD,
Yes, when we have so little water that it’s partial pressure as gas is less than 6 mbar, it’s never liquid (except for limited time as supercooled or superheated liquid). That depends only on the amount of water, not on ambient air pressure.
If there was no CO2, the quiescent state of the earth would be closer to smowball earth, as nothing could thermally activate the water vapor and thus prevent it from semi-permanently condensing out of the atmosphere.
A. A. Lacis, G. A. Schmidt, D. Rind, and R. A. Ruedy, “Atmospheric CO2: principal control knob governing Earth’s temperature,” Science, vol. 330, no. 6002, pp. 356–359, 2010.
This is also an interesting article in that a GCM can be run from an initial snowball-earth state, and by adding CO2, one can understand how it evolves into our current climate.
Springer’s ideas of ocean acting as a “liquid H20” is only plausible in the comical sense, good for a laugh when introduced as a topic in a climate science classroom.
Pekka, “That depends only on the amount of water, not on ambient air pressure.”
How much energy the air can hold depends on the local temperature and pressure. The air becomes super saturated as it cools and stays liquid if it can’t cool as fast as its surroundings. If you assume that CC and surface temperature can estimate the moisture, then you have to be assuming a constant rate of convection. Mixed phase clouds can form in the evening as the cloud base decreases in altitude. If you don’t know the local conditions you can’t predict anything.
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(2002)059%3C1779%3AOMSOMM%3E2.0.CO%3B2
That is a neat study of mixed phase clouds mainly in the US great plains. They used altitude instead of pressure, but that is not a well mixed atmosphere.
CD,
The water vapor becomes supersaturated, not air. Whether water vapor is supersaturated or not depends only on temperature of and absolute humidity (or equivalently on the partial pressure of water), not on air pressure.
Air pressure does affect thermodynamics in many ways, but not dramatically.
Pekka, my good comment got caught in moderation, but boundary layers do have an impact on the physics and supersaturated air makes a great boundary layer.
captd, you probably just have wrong terminology because a supersaturated boundary layer makes fog.
My contention is that if the atmosphere were nothing but nitrogen and water vapor the surface temperature would not be substantially different because the ocean is the big Kahuna as far as greenhouse warming is concerned. If the atmosphere were absent, like on the earth’s moon, there would be no ocean and no greenhouse warming. If we had an atmosphere but no ocean there would be no significant greenhouse warming. The ocean is what makes the earth warm enough for life as we know it not the atmosphere except for the fact that a surface pressure of 14.7 psi allows an ocean to exist in a wide enough temperature range that it doesn’t boil away.
WebHubTelescope (@WHUT) | September 15, 2013 at 1:32 pm |
“Springer’s ideas of ocean acting as a “liquid H20″ is only plausible in the comical sense, good for a laugh when introduced as a topic in a climate science classroom.”
Presumably you meant to write “liquid GHG”. That would be close. Liquids and gases are both fluids. I fail to see why a fluid with the same properties as a greenhouse gas would not also be a greenhouse agent. Specifically those properties are opacity to longwave and transparency to shortwave. Explain to me, if you can, exactly why liquid water cannot be a greenhouse fluid.
JimD, “captd, you probably just have wrong terminology because a supersaturated boundary layer makes fog.”
Fog or clouds which can be water, ice or both and not necessarily thick enough to see well. The ABL creates a convective capping zone during the day near the saturation point which at night turns into the nice inversion layer that keeps conditions nice and muggy down here even on a clear night. The Atmospheric Boundary Layer (ABL) is called a boundary layer because it is a boundary layer. You don’t have a nice predictable lapse rate or constant specific humidity ratio across atmospheric boundary layers. So over the tropical oceans we have an ocean of water about 2000 to 3000 meters over our heads that has its own latent, radiant and convective thing going on.
WebHubTelescope (@WHUT) | September 15, 2013 at 1:32 pm |
“Springer’s ideas of ocean acting as a “liquid H20″ is only plausible in the comical sense, good for a laugh when introduced as a topic in a climate science classroom.”
I’m sure they could use something to laugh about these days. Happy to return the favor because climate science has become a big joke due to the pause. :-)
Pekka, please answer the following:
Without an atmosphere there would be no global ocean.
[ ] true
[ ] false
My point was that the most important function the earth’s atmosphere performs is making a global ocean possible. Regardless of how anyone wants to change what I wrote this was my only assertion. I made no mention at all of how much water vapor the atmosphere can contain at various pressure levels as that has no relevance whatsoever to my point.
WebHubTelescope (@WHUT) | September 15, 2013 at 12:48 pm |
“Politically correct explanations do not help when you try to apply that science to a technology. You can’t engineer a product to work based on a political explanation for some scientific phenomenon.”
You mean like trying to limit CO2 emissions at a cost of trillions of dollars with the result being a reduction of 0.05C in the year 2100? That kind of application of politically correct ideas to engineering problems? If that’s what you meant then I agree but it raises the question of why you’d possibly support a costly engineering effort that yields no practical benefit. I assume the answer to that question is you’re a zealot with a chip on your shoulder and you don’t give a fig how stupid you look to an engineer who understands that the consensus demand for CO2 regulation is a hideously expensive boondoggle.
It’s obvious that the pressure that prevents boiling of water is essential, but there’s plenty of leeway in that.
Another obvious thing that we need GHE in the atmosphere to keep the surface warmer than the effective radiative temperature of the Earth. That’s the 33 C up to a correction from the unavoidable change in albedo. Nothing that happens in oceans can do the same for the surface.
Pekka Pirilä | September 15, 2013 at 6:35 pm |
“It’s obvious that the pressure that prevents boiling of water is essential, but there’s plenty of leeway in that.”
It’s not often you agree with the obvious. I wouldn’t describe the leeway as “plenty”. No telling what all would happen if the boiling point of water at sea level was say 50C instead of 100C. You didn’t put much if any thought into the implications is my guess and neither did I except inasmuch as I recognized it needs more thought before deciding there’s “plenty of leeway”.
“Another obvious thing that we need GHE in the atmosphere to keep the surface warmer than the effective radiative temperature of the Earth.”
No, this is not obvious. Liquid water has the requisite properties of transparency to shortwave and opacity to longwave that distinguish greenhouse gases from non-greenhouse gases. Instead of just waving your hands with unsuppported assertions I challenge to describe why the ocean does not exhibit a greenhouse effect independent of the atmosphere. I do not believe you can make that case but I welcome you jto try.
“That’s the 33 C up to a correction from the unavoidable change in albedo. Nothing that happens in oceans can do the same for the surface.”
I disagree. Why can’t it? The ocean is warmed to depth at the speed of light as shortwave traverses the vertical column with impurities in the water gradually thermalizing the energy. The thermal energy cannot escape radiatively due to water’s opacity to longwave. The energy at depth must therefore be mechanically transported to the surface where it may shed the energy by the usual mechanisms including (in order of importance) latent, radiative, and conductive.
This unimpeded penetration of shortwave and impeded release of longwave is the very essence of greenhouse warming and you need to be very specific as to why it works in a gas but not in a liquid. Good luck.
Springer:
So you fail in more ways than one. Your idea of the ocean acting like a “liquid GHG” is preposterous. You seem to believe that just because you can put words together that it makes a valid argument is wrong-headed. Perhaps if you try to sketch out some math and try to show how a “liquid GHG” would work, we could feel some empathy for your efforts. But as it is, you are the usual pompous denier that pulls in the occasional sucker who will believe in your FUD.
Springer:
I already did. A thick layer of water will block all infrared wavelengths. Since it is flat across the spectrum, the temperature can not compensate to favor a particular wavelength band and so will adopt a Planck blackbody spectrum to balance the incoming radiation.
Would you like some math to go with that?
A thin film of water will stop IR. It is not really the point. The oceans are warmed by solar SW – they lose energy from the top millimetre by IR, evaporation and conduction. There is no blackbody here at all.
The Earth emits according to the Planck distribution. The peak of this distribution varies with temperature. At Earth temperatures this is enough to make a speck of difference.
What changes is scattering of IR photons in the atmosphere.
Webby understanding of atmospheric is distorted along the usual space cadet paths. There is – they believe – less IR being emitted with more CO2 in the atmosphere. It may be but only for so as it takes for the oceans to equilibriate. It may be moot as the oceans are never in equilibrium and the large changes in toa flux from natural variability dominate.
David, “You didn’t put much if any thought into the implications is my guess and neither did I except inasmuch as I recognized it needs more thought before deciding there’s “plenty of leeway”.”
It is amazing how much leeway there is. It is like just about the perfect surface pressure was found.
Fascinating the way that the mind of a krank works. Here Springer makes a hand-wavy assertion in his first sentence, yet then accuses others of “waving your hands with unsupported assertions” when they are simply referencing black-body radiation physics.
If that ain’t a heavy dose of psychological projection, I don’t know what is.
David,
Earth surface at the present temperature emits about 396 W/m^2 of energy as IR. Earth as whole absorbs about 240 W/m^2. Nothing that occurs below the surface affects that. Without GHG’s in the atmosphere the Earth would cool with the power of over 150 W/m^2. That would lead to a very fast drop in temperature until the surface would be so cold that the radiation from the surface would be close to the absorbed solar radiation. At that point we would have a snowball Earth, if water is available for that.
The gas atmosphere with GHG’s does have it’s effect because the adiabatic lapse rate is highly negative making such a situation stable where the temperature drops around 70 C from the surface to the tropopause. That makes it possible that the Earth has an effective radiative temperature much lower than the surface temperature.
A gas atmosphere has a highly negative environmental lapse rate, because its compressibility is large. When compressibility is large the gas does a lot of work when it expands, and cools from the conversion of heat to work.
Liquid water has a very small compressibility. A situation where the surface is much colder than the bottom is stable only in solar ponds where a strong salinity gradient is maintained artificially. In a solar pond “a greenhouse effect” is present as solar SW penetrates deep but no effective mechanism can bring heat from the bottom to the surface. In a solar pond the bottom is heated by the effect, not the surface. The oceans don’t have enough salinity gradient to act as solar ponds, they don’t have hot bottom layers, and we live at the surface.
The oceans act as large heat stores, they affect the climate in many ways, but without GHG’s in the atmosphere they could not keep the surface warm.
Where is this 0 millibars place located?
Cause I need a drink
When I get to 0 Kelvin do I turn left or right?
Pekka I read your objection as there is no mechanism in the ocean for a cold top layer to trap heat in a lower layer. You go on to explain a solar pond defeats this by floating a high salinity layer at the surface of the pond which may be much cooler while maintaining a lower density.
Of course that’s quite correct.
The atmosphere over the ocean is the cold layer which traps the heat in the ocean. It doesn’t matter if the atmosphere is pure nitrogen it will still be colder than the water and serve the purpose of trapping the heat in the warmer layer below causing its temperature to rise until the Planck effect causes its temperature to rise until equilibrium is restored.
Still no update from Judith or Nic reconciling the statements about TCS here with the denial of the IPCC attribution statement concerning warming since 1950.
It is difficult reconciling your cognitive dissonance about the pause, let alone about attribution.
================
http://online.wsj.com/article/SB10001424127887324549004579067532485712464.html
Dialing Back the Alarm on Climate Change
A forthcoming report points lowers estimates on global warming
By MATT RIDLEYLater this month, a long-awaited event that last happened in 2007 will recur. Like a returning comet, it will be taken to portend ominous happenings. I refer to the Intergovernmental Panel on Climate Change’s (IPCC) “fifth assessment report,” part of which will be published on Sept. 27.
There have already been leaks from this 31-page document, which summarizes 1,914 pages of scientific discussion, but thanks to a senior climate scientist, I have had a glimpse of the key prediction at the heart of the document. The big news is that, for the first time since these reports started coming out in 1990, the new one dials back the alarm. It states that the temperature rise we can expect as a result of man-made emissions of carbon dioxide is lower than the IPPC thought in 2007.
—more at link
Dazed and confused, Western science staggers into a future about which they haven’t a clue. Michael Mann is the Karl Marx of Climatology.
Right now we have over 65% more Arctic sea ice area, a record high sea ice area around Antarctica, a record low tornado season, record late start hurricane season, 15 years of no global warming, a cooling tropical Pacific and a “strongly cooling Southern Ocean”.
The above are just some examples illustrating just how embarrassingly wrong climate science has been. ~P. Gosselin
Are we in danger of a runaway pausing of global warming? The current pause has seen the death of millions across the Earth.
I found this document by Nic Lewis to be troubling. Lewis appears to be intelligent as well as serious about climate issues. If he were to address these objectively, I think he has the potential to contribute substantially more to the field than as an advocate who creates false impressions in his zeal to emphasize those data that support low values for equilibrium climate sensitivity (ECS). Indeed, he has criticized the Met Office Report, which I haven’t read, for misrepresentations, and perhaps the Report is guilty on all counts, but if Lewis himself has made misrepresentations with the deliberate intention of creating a false impression, that action comes perilously close to dishonesty. I’ll let readers judge that possibility, starting with his own comments about a section of the report. He stated:
“Misrepresentations relating to equilibrium climate sensitivity (ECS).
Estimation of equilibrium climate sensitivity is dealt with in Section 4 of the Met Office Report. It repeats the misleading claim that “Positive feedbacks in the physical climate system, the largest of which is the water-vapour feedback, increase this number [ECS] to over 2°C”, and compounds this distortion by stating that “the fundamental physics of climate sensitivity, involving black body radiation and water vapour feedbacks … alone give a climate sensitivity of at least 2.0°C”. As already pointed out, these claims ignore the negative lapse-rate feedback, which is intimately linked to the water-vapour feedback. After including lapse-rate feedback as well as water-vapour feedback, all the models analysed in Soden and Held 2006 had a climate sensitivity of below 2.0°C.”
I expect that many readers knowledgeable about climate science and familiar with Soden and Held 2006 (SH06) may have compared that statement with their recollection of SH06. The questions for those and others are the following: (1) How many ECS values in SH06 were below 2.0C? Some? All? None? (2) How many values in SH06 does Lewis intend the reader to believe were below 2.0C?
Nic Lewis of course is entitled to his own opinions about various data in SH06, but that doesn’t touch on the question of honesty. Readers can revisit SH06 to draw their own conclusions on that question. I happen to believe Lewis has been wrong on many points in his long disquisition regarding TCR, ECS, aerosol forcing, the relationship between “effective climate sensitivity” and ECS, etc. (which is not to say that the Met Office was not itself wrong on many points). I won’t dwell here on why I disagree with his conclusions, but if he hopes to be taken seriously, he would do well not to commit the sins he imputes to others.
Many commentators appear more interested in advocating a preconceived conclusion than conveying an accurate understanding of climate phenomena, but most of them are neither very smart nor well informed. I think Nic Lewis is both. He can and should do better.
Well, Fred, Nic seems to be a lot more effective at getting at the truth of the matter than you ever have been. That should be troubling.
===============
Climate sensitivity was exaggerated to manipulate the masses through fear and guilt. Some were very happy with that.
==============
David, I always love it when a situation can be described interchangeably with imminently, eminently, and immanently.
==============
Heh, any editor would strike that misspelling. Oh well, my last comment is now cryptic enough even I don’t get it.
==============
Is it me, or is this incredibly passive-aggressive? I see multiple implications of fault, a suggestion of dishonesty and implied statements of fact. What I don’t see is a single meaningful statement, a direct criticism or piece of evidence.
What can a comment like this possibly contribute?
“What can a comment like this possibly contribute?”
Zero, and that is why it really pissed me off. Pure passive/aggressive BS in service of political advocacy.
> What I don’t see up is a single meaningful statement.
Even Chewbacca would have a hard time finding that
makes no sense.
Let’s try a set of statements, i.e. a paragraph:
> Many commentators appear more interested in advocating a preconceived conclusion than conveying an accurate understanding of climate phenomena, but most of them are neither very smart nor well informed. I think Nic Lewis is both. He can and should do better.
This paragraph does seem to make sense. Its function is to exhort Nic Lewis to more prudence.
Some may even liken this paragraph to what seems to be called paraenesis:
http://rhetfig.appspot.com/view?id=agdyaGV0ZmlnchgLEhBSaGV0b3JpY2FsRmlndXJlGNKJAgw
***
Admonishing does not need to be sustained through argumentation, as Brandon seems to presume. Its worth depends on its author. That Fred Moolten takes the time to write this adds to its weight.
This might explain the Denizens’ ad homs in response to Fred’s comment.
Quite fascinating just how selective is their “concern” about tone, accusations of misrepresentation, etc.
Selective reasoning is selective.
Fred,
” I won’t dwell here on why I disagree with his conclusions, but if he hopes to be taken seriously, he would do well not to commit the sins he imputes to others.”
Rich, much too rich. You, Fred would do well to actually lay out why you disagree with Nick’s conclusions, and let us evaluate the merit of your arguments (which I honestly think will be weak or nonsensical, but please show me I am wrong). Otherwise, some may think that you are acting simply as an advocate for a political POV. Your claims that Nick is being dishonest are risible when considered in light of the Met report, which is horribly biased, does indeed distort other people’s work, and does grossly and willfully misrepresent much..
Want us to take you and your comments seriously? If yes, don’t be shy, lay out your technical arguments so that we can evaluate them. I am betting you won’t… or can’t.
Steve – Thanks for your opinion. I haven’t participated much in climate blog discussions in the past half year mainly because it tends to degenerate into angry arguments rather than thoughtful discourse, and I don’t particularly enjoy arguing since I’m not very good at persuading people to change their firmly held convictions. My comments were intended primarily for bystanders who know something about climate and might want to form their own judgments rather than for individuals who want to defend or attack views expressed by others. I do hope those bystanders will read what I wrote, review the Soden and Held paper, and decide for themselves whether or not it supports my statements. I’ll leave it at that and regretfully decline your invitation to elaborate on my disagreements with what Nic Lewis has written regarding all the other climate phenomena.
Here’s S&H06:
http://www.gfdl.noaa.gov/bibliography/related_files/bjs0601.pdf
Did the A of this op-ed contact Held?
Hmmm, good point, Fred, I wonder if Lewis was confused by SH06’s units where ~1 W/m2/K is actually in excess of 3 C per doubling for these models.
Fred Merd,
That is how I figured you would respond. I will conclude that whatever factual arguments you have, they are not worthy of discussion.
“I’m not very good at persuading people to change their firmly held convictions.”
Nobody asked you to try to change anybody’s convictions. Just make a factual argument instead of the cowardly passive/aggressive rubbish you posted. Your comment was a blow far below the belt. I do not usually become angry about blog comments; yours was the rare exception.
Jim – At first, I too thought Nic Lewis was simply confused because climate sensitivity was described in terms of radiative restoring per unit temperature rather than temperature per radiative imbalance. However, on close reading, I realized he wasn’t confused, but rather that he created a false impression that the SH06 values for climate sensitivity were all below 2 C (when they’re actually all above it) by ignoring the SH06 cloud feedback terms in writing his comment. As I said earlier, he can hold any view he wants on cloud feedback, but honesty (in my view) requires him to report what the authors stated rather than misrepresent their conclusions. In any case, readers can look at SH06 and make up their own minds.
Fred Moolten continues the passive-aggressivness:
This effectively says he quit posting here regularly because the people who disagreed with him often are close-minded fools. He continues this depiction by saying:
Which further implies anyone who would disagree with his whiny description of this post is also a close-minded fool. And this is all wrapped up with the beautiful comment:
Where he basically says, “Look it up.” And then in a follow-up comment, he drops all pretenses and flat-out accuses Nic Lewis of dishonesty:
Personally, I think anyone who writes comments like these has no room to talk about discussions “degenerat[ing] into angry arguments rather than thoughtful discourse.”
Unless he’s taking pride in sabotaging them.
Like any other Denizens, Fred has the right to come here, state his opinion, and be done with it. Many do, and I can provide names on request. This right is as old as bulletin boards.
In return, others are also entitled use ad superbiams to make him spell out his case, e.g.:
On the other hand, piling on will always be.
***
Fred’s argument amounts to: read S&H06. If any of you find this argument abhorent, I have similar arguments that I would like to have evaluated.
***
Speaking of S&H06, according to my PDF reader’s search function, the word “median” does not appear in it. So it might be fair to say that Soden & Held did not insist on the median ECS for the model ensemble they studied.
Fascinating. So, apparently, Fred’s comments imply whatever Brandon determines that they imply.
You know, “basically.”
Joshua, I made a claim. Like any claim, it could be wrong. The fact I made the claim does not mean I am stating my interpretations are absolutely correct or that I get to dictate the meanings of words and sentences.
You’re welcome to dispute my criticisms of Fred Moolten’s passive aggressiveness with nothing more than passive aggressiveness of your own. You’re welcome to not even take a position, but merely imply I’m wrong.
You’ll just look like petty person with nothing useful to contribute.
So just like Springer elsewhere in this thread, all that is important is making a claim. Springer rationalizes his krackpot ideas by saying all that is important is claiming that he could provide an explanation for an observation. Doesn’t matter if it is wrong or right. The rhetorical point-scoring is what matters. Same for Shollenberger.
Must remind them of their high-school debate days,
George E.P. “Trick” Box once said: All claims are wrong, some may turn out useful.
> Fred Merd, […]
Is this a typo, Steve Fitzpatrick?
I’m not sure why my comments aren’t linked to properly. Here’s another try.
The comments are broken because I called you a boor with delusions of grandeur who was imminently ignorable. Most of the other responses tend to agree but in more couched language. The directness of my reply earned it a disappearing by the hostess and such disappearances cause what’s been described as orphaned comments further down in the thread which have no predecessor linked to them.
Thanks for asking. You should do more asking and less telling if you’d like to be taken seriously.
What has happened to you, freddie? You used to be civil and reasonable, like Pekka. Now you are in the sad position of having the boards’ nasty clowns defending your petulance. We want the old freddie back.
It was civil and reasonable, Don Don.
You may have no idea how far you can go by being civil and reasonable.
Don,
Fred is not a “go along to get along” establishment beltway villager.
That was a genuinely cranky comment.
Which is better than a comment by a genuine crank.
Hmmm might be better not to have any comment at all if it doesn’t add value to the discussion. The humour from you in this instance was appreciated WHT.
If this is a genuine error by Nic Lewis could we now say his errors so far all seem to go in the same direction….convenient to the skeptic cause.
hmm….
Even if these are in the end justifiable choices, they still do seem to go in the same direction.
Fred,
I thought what Nic wrote: “A multi-model study of feedbacks, Soden and Held 2006, showed a median ECS for the model ensemble of 1.8°C after combined water vapour/lapse rate and surface albedo feedbacks.” was clear enough, but if you disagreed, then why not simply note that he should have been more clear about that value not including positive cloud feedbacks? It was the accusation of deceit which was, IMO, neither appropriate nor fair.
> It was the accusation of deceit which was, IMO, neither appropriate nor fair.
Here was Fred’s accusation:
Since Fred also mentions that honesty is on the line, does that mean that when the A’s talk of errors, misrepresentation, and misleading claims is a matter of honesty?
Seems that this is Fred’s reading.
Seems that this is also Steve Fitzpatrick’s reading above:
> The goal of the report seems to me only to cloud the water with very questionable claims which will delay public perception of a new scientific consensus on lower sensitivity; they simply want to delay changes in public opinion for as long as possible.
http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-379651
Fred and Steve Fitzpatrick do seem to have a meeting of the mind on this question.
***
I don’t think there are any technical documents pertaining solely on climate science deal with issues of honesty.
If Fred and Steve Fitzpatrick’s perception of this A’s op-ed is remotely correct, to portray it as only or mainly (the joy of adverbs!) a technical comment might very well be a misrepresentation.
> I don’t think there are any technical documents pertaining solely on climate science deal with issues of honesty.
What I think is the case is that there are no technical documents in climate science that deal with issues of honesty.
You are being played, folks.
steve –
When, in your opinion, are “accusations of deceit” appropriate and fair? Do you apply those criteria evenly?
Joshua,
What I objected to in Fred’s comment is simple to understand. If he thought that Nic Lewis had not accurately represented the content of Soden&Held, he should just have stated clearly what he meant; something like:
“Nic, I think people might conclude (incorrectly) from your essay that Soden&Held showed the models they examined had a climate sensitivity below 2C, when in fact that was the sensitivity before the influence of positive cloud feedbacks. S&H show that the models they studied have an average ECS of well over 3C per doubling. You may want to clarify that the under 2C figure you used from S&H includes no positive or negative cloud feedbacks.”
That sort of comment would have stated clearly what Fred was objecting to, and not even caused a stir. Fred then makes the situation worse by suggesting that he thinks most of Nic’s technical arguments are wrong, but will not take the time to tell us why (and seems to be saying, ‘I would never waste my time or stoop so low as to actually engage Nic Lewis, or anyone else, on the technical substance, but trust me, Nic is wrong..’). On top of all that, he implies that people who disagree with him (Fred) are mostly uninformed and stupid. This is exactly the kind of rubbish I expect to from Joe Romm or the RealClimate team. Fred’s comment might be better received on those blogs, where obnoxious arrogance is the norm, and completely acceptable.
It seems a little hypocritical Steve Fitzpatrick for you to complain about tone given the tone of your comments directed at the Met Office report. You seem quite happy to interpret errors into accusations of deceit but not when it is done back at you.
What I find fascinating about the concern trollery is that Fred Moolten has had a longstanding reputation on Climate Etc of being very measured and patient in his explanations, rarely getting wound up.
In fact, most of the skeptics here applaud him (and Pekka) and use Fred as a paragon of decency — as opposed to me, whom they consider rabid.
So one comment showing frustration is met with a huge backlash. There goes all the built-up goodwill. POOF !
It just goes to show you that the relevant watch phrase is: Don’t give them an inch, because they will take a mile.
Fred, Don’t let the bastards grind you down.
> If he thought that Nic Lewis had not accurately represented the content of Soden&Held, he should just have stated clearly what he meant; something like: […]
then follows an example of what Nic Lewis did not do.
***
> That sort of comment would have stated clearly what Fred was objecting to, and not even caused a stir.
While that it would not have caused a stir is an empirical matter, what we can see is that Nic Lewis’ comment did cause a stir, e.g.:
http://www.dailymail.co.uk/news/article-2420783/Global-warming-just-HALF-said-Worlds-climate-scientists-admit-computers-got-effects-greenhouse-gases-wrong.html
Steve Fitzpatrick seems to suggest that “causing a stir” is a bad thing. Interestingly, he does not seem to suggest that what Nic Lewis did was a bad thing.
INTEGRITY ™ — We’re Here to Stir.
***
Was Nic Lewis’ memorandum leaked to friendly journalists?
lolwot,
My tone? I said pretty clearly that I considered the Met report to be a political document, and that its technical content was a result of that. I did use the word ‘reprehensible’ for scientists who generate political documents in the name of science; it is a word I do not use lightly, and I used it because I think those scientists are damaging the public credibility of climate science by using it and to try to advance a political agenda. IMO, the scientists at the Met should be focusing on figuring out what is wrong with their costly and publicly funded model (and one of the ones that is furthest from reality, with comically high diagnosed sensitivty), not trying to avoid a reckoning with reality via political screeds. You are of course free to disagree.
Steve –
These threads are full of people accusing others of willful misrepresentation when, in fact, evidence supporting those accusations is lacking.
I haven’t really examined Fred’s post to think much about the veracity of his comments here, but if he has done as you suggested, it would be but a drop in a very large bucket.
Here is one other, particularly notable drop:
http://judithcurry.com/2011/07/05/the-ipccs-alteration-of-forster-gregorys-model-independent-climate-sensitivity-results/
It is the first thread were Nic posted here at Climate Etc. You will notice that he wrote a strongly implied accusation of willful misrepresentation – one which many “denizens” interpreted so as to support their presupposition of climate scientists lying and the like. Nic then goes on to, further, offer an entirely implausible explanation (IMO) for how he went about investigating the questions he had about the work he was writing about. You will notice that in that thread, I offer a suggestion of what Nic could have done that would have been more productive than what he did – in a manner similar as you just offered a suggestion to Fred.
My point in asking you about the uniformity of your standard was not to question whether Fred was guilty of a similar offense, or to question whether such accusations (usually not based on a scientific approach to quantifying and validating the supporting evidence), but to point out that the objections that people raise about such accusations in these blogophseric threads, indeed, the “concern” that people express, is almost uniformly selective. It was also not to highlight that you, individually, might not be entirely uniform in how you apply standards. But if you take the time to look at that previous thread, do you find it interesting to reflect on how your standards should be applied to Nic.
My point is not to say that “they do it to” or “he did it first” in order to defend such argumentative and in the end, IMO, counterproductive bickering – but to go back to a brief conversation that you and I had about the prevalence of earnest conversation versus confirmation-bias-based bickering in these threads.
Perhaps you don’t know about Fred that he has a well-established record here at Climate Etc. of participating in long and extensive exchanges, at notable levels of technical depth, with people that disagree with him on a range of issues – and to persist in maintaining a measured tone even when his interlocutors direct much personal venom his way (without responding in kind).
You are certainly entitled to your conclusions about where he might be better off participating, but you might want to look through the archives a bit to gather more information, or otherwise you might not realize that you are forming conclusions that could be inconsistent with easily available evidence. Perhaps Fred’s expression of the reasons for his reluctance to engage further could be entirely accurate, and not the “rubbish” that you seem to think it to be.
And Steve –
In case you forgot:
http://judithcurry.com/2011/07/05/the-ipccs-alteration-of-forster-gregorys-model-independent-climate-sensitivity-results/#comment-83440
Joshua, “It is the first thread were Nic posted here at Climate Etc. You will notice that he wrote a strongly implied accusation of willful misrepresentation..”
With climate science that verges of being a compliment. After all it implies they actually knew what they were doing :)
Yes, it’s a good joke. But with a similar application of binary thinking, Cap’n, we could make any branch of science the brunt of the same joke. For that matter, libertarians and “skeptics” could be the subject of the same joke, as no doubt could fisherman.
And don’t even get me started on how many HVAC contractors I’ve met that don’t have a clue what they’re doing.
Joshua, “And don’t even get me started on how many HVAC contractors I’ve met that don’t have a clue what they’re doing.”
It all boils down to when something goes wrong. Then you have that binary choice, “I listened to an idiot” or “I was taken in by a fraud.” Most of the time everything works out pretty well, that is the huge gray people forget. But when someone says they have a 95% confidence, there is a line drawn and only a binary choice to make. Which would you rather be? Just another idiot or a cunning fraud?
I don’t think it’s about listening, Cap’n.
Climateball is a word placement discipline.
In this op-ed, the expensive word was “misrepresentation”.
Willard, “misrepresentation” is a common theme. Do you believe, yes believe, that there is any validity to a 95% confidence level that CO2 caused “most” of the warming from any point in time? Would you stake your reputation and career on it? Now do you believe that someone with their reputation and career on the line might fudge things?
Joshua,
“Perhaps you don’t know about Fred that he has a well-established record here at Climate Etc. of participating in long and extensive exchanges, at notable levels of technical depth, with people that disagree with him on a range of issues – and to persist in maintaining a measured tone even when his interlocutors direct much personal venom his way (without responding in kind).”
I am aware of Fred’s participation in the past. This is one of the reasons I was very unhappy with his comment, which was far from measured, and IMO, intended only to discredit without offering substance. He did not even explicitly state what he objected to until pressed by other commenters. I already wrote what I think would have been a fair and reasonable way to address the issue of Soden&Held with Nic Lewis, but most anything other than the comment he actually made would have been an improvement.
With regard to Fred refusing to engage in a technical exchange: Simply declaring that he thinks Nic is wrong without offering any reasoned explanation, even when that explanation is requested, is indeed rubbish, IMO. If Fred wants to say Nic is wrong, then he has a burden to show why. Consider the possible exchange:
Steve: “Joshua is evil and corrupt.”
Joshua: “Why do you say that?”
Steve: “I couldn’t be bothered to explain, it is obvious to all the smart people who comment here; only the stupid ones think otherwise, and I would be just wasting my time on them… and most of the people here are in fact stupid.”
Joshua: “You call me evil and corrupt, but won’t say why?”
Steve: ” If any smart bystanders want to confirm that Joshua is evil and corrupt, they can just read over all the things he has written in the past and confirm it.”
Joshua: “You are an obnoxious a$$hole.”
And your conclusion in this case would be perfectly justified. Feigned, civility (“Thanks for your opinion.”) is not the same as civility.
Cap’n,
You ask:
> Do you believe, yes believe, that there is any validity to a 95% confidence level that CO2 caused “most” of the warming from any point in time?
No, as I am agnostic:
http://neverendingaudit.tumblr.com/post/1105313146
I see no point entertaining any belief regarding specific issues in science.
Here are some beliefs I entertain.
1. I believe that science proceeds by way of the best explanation:
http://neverendingaudit.tumblr.com/tagged/BestExplanation
2. At least to remain in character, I have to say I believe that holism wins:
http://neverendingaudit.tumblr.com/tagged/HolismWins
This means that the Met report might very well be warranted to claim that:
> Each method has its own assumptions, and so it is not possible to say that one method is superior to the others.
3. I don’t believe Nic Lewis’ allegation of undetermined misrepresentations were meant to have the Met report issue a corrigendum for some nits he found on figures or tables.
4. And speaking of passive aggressive behaviour, I don’t believe Denizens (go team!) have anything to counter this, and just like Steve Fitzpatrick succeeded in ignoring my comments so far, will indulge in another concert of crickets.
Willard, “3. I don’t believe Nic Lewis’ allegation of undetermined misrepresentations were meant to have the Met report issue a corrigendum for some nits he found on figures or tables.”
They were his nits, plus the 68 other A’s. I doubt Nic expects much of anything from the MET, but he does have the right to defend his nits. In his opinion, his/their (the 69 or however many authors) nits were misrepresented but Nic is expressing his own opinion and not representing the 69. There are a lot of fields that have little but nits to defend, so don’t belittle Nic’s nits.
You may recall that there has been considerable discussion on whether there is or is not a pause in warming. The total warming from 1980 to 1998 was about 60 nits, since 1998 there has be maybe 6 nits with a margin of error of about 12 nits. That is not a lot, but to some the fate of the world as we know it depends on those nits. If someone had not cared dearly for those nits and though they could accurate measure those and predict future nits, we would all be doing something a lot more productive. Like possibly having a barbeque summer of nits :)
You might need to squirrel more nits for your barbecue, Cap’n.
Perhaps you’d rather pick squirrels from Nitting:
http://en.wikipedia.org/wiki/Nitting
“It was the accusation of deceit which was, IMO, neither appropriate nor fair.”
Ha this is rich! Accusations of deceit is climate skeptic 101!
You climate skeptics don’t like it back at you do you?
But albedo just makes it worse. Note that on its own it is positive, so adding this to the water vapor and lapse rate feedback is far above a 2 C sensitivity. Did he misread Figure 1 to assume the surface albedo column was cumulative of the columns to its left? We know surface albedo is a positive feedback. Where did 1.8 C come from?
Well, a day later it looks like the defenders disappeared, so we’ll never know.
JimD,
The best we can do is terminate the comment branches with some science sanity.
Yet as Richard Alley has opined, it is hopeless because the denier zombies will keep coming back.
Now I think I see. From SH06 Table 1, the effective sensitivity is 1-1.5 W/m2/K with all feedbacks, which is ~3C per doubling. But what he has done is zeroed out the cloud feedback to give something more like 2 W/m2/K which gives < 2 C per doubling. So he gets it by assuming cloud feedback is zero which is well below what any of the models give. He is complaining that the Met Office said you need a strong negative feedback for the 1.8 ECS claimed by Otto et al. After then claiming that the Met Office intended to put the lapse rate feedback with their positive feedbacks, and ignoring the positive cloud feedback, he can get the SH06 "positive" feedback to be 1.8 C per doubling, but only by redefining what they mean by positive.
The most common attribution is to assign 1.2 C of warming to CO2 by itself, about 1.5 C to water vapor which gets “control knobbed” by the CO2 and the remainder of 0.3 C to albedo and other GHGs. This gives about 3C for doubling of CO2.
Hey Fred is there any particular reason you keep mucking with your blog profile. In this thread you changed the link associated with your name from facebook to none to google +1. Just curious. The motivations of computer illiterates fascinates me.
WordPress doesn’t seem to want to allow me to log in via my former profile links. I may try a few more times, then give up and stick with Google or Facebook.
I try my best to avoid illiteracy, including the error of using a singular verb with a plural subject.
There’s humor in calling something “illiteracy” just for being wrong.
There’s humour in calling Fred illiterate whence Big Dave does not realize that he’s trying different logins.
Ah yes. Our “skeptical” friend comes up with yet another logically determined conclusion, after weighing all the evidence carefully, evaluating all obvious and even subtle alternative interpretations.
Springer draws his conclusion that Fred is computer illiterate only after careful consideration of uncertainty.
Why do these boyz insist on giving noble skepticism such a bad name?
The Met Office’s response to David Rose’s political hit job included a comment that is relevant to this thread:
http://metofficenews.wordpress.com/2013/09/15/met-office-in-the-mail-on-sunday/
Yes, but misrepresentation.
Essex on the rabbit-holers: http://www.youtube.com/watch?v=hvhipLNeda4
Pretending numerical models “solve” climate equations.
Time for more reading of Nic Lewis’ “memorandum” (scare quotes ™ Auditing Sciences). We can analyze the whole Figure 1 and Table 1 section in one go.
***
First, we note some adverbs, one of which (“accordingly”) was already seen in the previous paragraph (not “chapter”, of course — we thank Moshpit even if he did not notice that nit):
Figure 1 does not use the Otto et al primary TCR best estimate of 1.3°C and 5–95% range of 0.9 to 2.0°C, based on data for the decade 2000–09. Although caution is required in interpreting results for any short period, arguably – as stated in Otto et al – the estimate based on the most recent decade’s data is the most reliable since it has the strongest forcing and is much less affected by the 1991 eruption of Mount Pinatubo. Accordingly, showing in Figure 1 only the (wider) TCR estimated range based on 1970–2009 data for Otto et al for comparison with other estimates is misleading.
What Nic Lewis does here is to repeat the main argument in Otto&al 2013 for the claim that the data from the last decade provided the best estimate. This argument does not respond to any of the arguments we can read in the Met Report.
Considering that the Met Report rejects Otto & alii’s claim that the data from the last decade provided the best estimate and that Nic Lewis does not refute the Met Report’s arguments, Nic Lewis’ “misleading” claim would deserve more diligence from his part.
***
Second, Lewis’ point about the classification of Harris et al 2013 only matters for Lewis’ own position, and only insofar as the colours of his flasks matter in the grand scheme of things. Since the Met Report does not claim that observation-based estimates are superior to model-based one, like Lewis does, this classification does not matter much for the conclusions of the report.
This point is also important in the discussion that follows: without having Harris et al 2013 on its side, Otto & al 2013 may look alone in its corner.
***
Third, notice how Lewis distinguishes his third point from his fourth point. Watch the pea:
– Otto & al 2013 used the median;
– Harris et al 2013 used a median;
– Gillett et al 2013 used a mean;
– CMIP3 used a mean;
– CMIP5 used a mean.
Now the thimble:
> The central TCR estimate of 1.6°C given for Gillett et al 2013 is a mean, and is not comparable to the median estimates quoted for Otto et al and Harris et al 2013.
In that sentence, Gillett et al 2013 is isolated and opposed to two sources.
Look at the other sentence:
> The multi-model CMIP3 and CMIP5 central TCR estimates given of 1.8°C are also means rather than medians.
CMIP3 and CMIP5 are both discharged in one go, without further ado.
***
In other words, only by changing the colour of Harris et al 2013 and by using medians instead of means can Lewis claim that:
> A revised version of Figure 1 in the Met Office Report showing the impact of the revisions discussed above, and a better idea of the distribution of probability, is shown in Figure 1.
We conclude with some questions:
Q1. Why would this show a better idea of the distribution of probability?
Q2. What does showing a better idea of the distribution of probability even mean?
Q3. Why would medians be preferred to means, i.e. how does removing run weights add any information?
Q4. Why not show both or do some mediation on the matter instead of crying some “misleading” wolf?
Q5. Is “misleading” or “misrepresenting” the opposite of “showing a better idea”?
Q6. Is this section of Lewis’ memorandum really a technical comment?
O, the joy of adverbs!
Hmmmm. The Met Office model runs too hot. Deliberately or ignorantly? Always the same question, the same question.
====================================
Hmmm. Nic goes for the lower bound justified disingenuousness can buy. Why would that leave anyone lukewarm about the technical content of such comment?
Have we listened to idiots, or been taken in by frauds?
H/t The Cap’n.
==========
With this question, Cap’n’s lukerwarm, Koldie.
Heh, have you listened to idiots or been taken in by frauds?
==============
I don’t listen, Koldie, I read.
And now I read Nic Lewis.
What were you saying about idiots?
Maybe you don’t have to take Nic seriously, but the Met Office does. Why don’t you go give them your suggestions?
===============
Read the thread, Koldie:
http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-380673
I suppose you don’t realize how pitiful that Met Office response is.
=================
I’ll make it easy for you. They don’t answer Nic, and they defend their model by saying it is within the absurd range of the IPCC. willard, the model runs hot. Does it do so deliberately or ignorantly? Something worthwhile auditing, wouldn’t you say?
======================
Over at the Bish’s a TerryS shows some evidence from Julia Slingo that it is deliberate. Auditors ahoy!
================
willard, you are just making a fool of yourself auditing nits while British electric rate unnecessarly skyrocket and old people die of the cold. This is the reality, not your sad sophistic ideal.
=========
Maybe Pekka or Fred can chime in with whether they think the Met Office model running hot is from ignorance or deliberation. C’mon guys, the Met Office needs help.
===============
willard, can you spot the circular argument in your link to the Met Office response? C’mon, Big Guy, you think you are good at this.
===========
I already gave it away. Search ‘absurd’. We are well into Kafka territory here.
=========
Answer: Nearly all the models run hot. Is it from ignorance or deliberation? Now there’s something worth auditing. Git to it, or remain irrelevant.
==========
The model is most probably running hot, because the historical process of its development has made it run hot. The present models are more strictly constrained by fundamental equations than earlier ones, but they do still contain semi-empirical parameterizations of subsystems that cannot be modeled from first principles
I don’t believe that it has been built by purpose to run that hot, but it’s possible that some of the subjective choices made by the model developers during the development process have been biased by the expectations of people who made those choices.
While all models are tuned in many different ways, they are not tuned specifically to run hot or cold. That cannot be done without affecting other properties of the models. In case of a model that has been developed to reproduce many details correctly those virtues would be lost in tuning based on one specific feature.
Further development of the models should take all new knowledge into account and lead step by step towards models that agree more extensively with observations.
I can’t disagree, Pekka, and your second paragraph tells the cruel truth about ignorance. Me, I’m with both, ignorant and deliberate.
============
Ah… here… http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-381063
Willard, “Hmmm. Nic goes for the lower bound justified disingenuousness can buy. Why would that leave anyone lukewarm about the technical content of such comment?”
Lowest reasonable bound would be more accurate. The low end of the IPCC range 1.5C not only assumes positive feedback, but significant positive feedback. The “no feedback” response should be ~1C/3.7Wm-2 with a range of uncertainty, +/-0.2 making a reasonable low end 0.8 possibly even a little lower. Everything greater than “no feedback” is an assumption. Since there is a Planck response that does impose an upper limit plus cloud uncertainty to the point the sign is not known, there is nothing disingenuous about including a reasonable lower bound.
So when the MET mentions their models are in the IPCC “recommended” range, they are admitting their model is biased high just like the rest. Remember the Charney Compromise, 2C Manabe, 4C Hansen plus with a wild ass guess of 0.5C uncertainty :)
lil kim,
Have you not looked at the BEST observational data and how that matches a 3C sensitivity to doubling of CO2?
How can that be a deliberate misrepresentation?
The land data BEST represents the expected ECS as it eliminates the heat capacity of the ocean.
Who can be fudging this data?
Is your ignorance deliberate, lil kim?
Webster, “Have you not looked at the BEST observational data and how that matches a 3C sensitivity to doubling of CO2?”
Then we should tax people that live between 30N and 60N into the stone age.
The temperatures are getting that high on land. Do you deny the high temperature anomalies?
Webster, there is nothing to deny. Per ERSST, which also has land only data, 30N-60N land temperatures increased ~1.75C from the early 70s through the late 2000s. That is about twice as much as the little land area in the 30S-60S band. The worst warming is in the 30N-60N range, so you guys should pay the taxes.
Looking at the Otto et al paper, I don’t understand the methodological choice they have made in using the full 40 year period. Including 1970’s and 1980s with equal weight in the calculation makes the final result much more uncertain than it would be if the decades were combined taking into account the higher power of the latest decades in the combined estimate.
Comparing with their value 1.4 C (range 0.7-2.5 C) the alternative method that weights the decades based on the uncertainties of the decadal estimates would lead to a slightly higher best estimate (still 1.4 C when given in tenths of degree) and significantly narrower uncertainty range (perhaps 1.0-2.0 C). That much can be seen from Figure 1b without any calculations. The uncertainties concerning the reference period 1860-79 combine differently from those related to the final period. That should be taken into account in estimating the uncertainty of the combined estimate, but the effect of that is likely to be very small.
Taking into account what the Otto et al paper contains, the choice of Met Office to use the values based on the 40 year average is reasonable. I would not fault Met Office for using the value with a wide error bar but the Otto et al paper as picking the last decade, when the previous gives a different result would be a biased choice.
Thanks, Pekka.
I think Otto & al 2013 are trying to dance under a volcano:
http://www.nature.com/ngeo/journal/v6/n6/full/ngeo1836.html
Nic Lewis simply repeated that argument.
Here’s the relevant bit about the Met report:
http://www.metoffice.gov.uk/media/pdf/q/2/Paper3_Implications_for_projections.pdf
I don’t think that “yes, but Pinatubo” cuts any ice. To be the knock-out argument it portends to be, Nic will have more dancing to do.
So far, it is the Met Office doing the Tarentella.
=========
One question at a time. we will
start with
Q1. Why would this show a better idea of the distribution of probability?
two Figures are compared. Figure 1. from the Met and Nic’s violin plot
Why does a violin plot show a better idea of the distribution of probability than the Met Chart.
A probability density function is defined by several parameters.
http://en.wikipedia.org/wiki/Probability_density_function
There are metrics for centrality ( mean and median)
There are metrics for range ( 5-95%, for example)
There are metrics for skewness.
To understand a PDF the more parameters you know the better.
In the Met display which isnt even a proper box plot, you have no information on skewness ( playtokurtic or leptokurdic ) in simple terms you dont
for a graphical display that shows all the information in a PDF you want to combine a box plot with a kernel density plot. This is known as a violin plot.
Violin plots show more information (momements ) than the misleading MET plot, which isnt even a proper box plot
There is plenty of reading material on the web
when you have finished, there will be a test.
If you can do better on the test than you do at counting sentences we can proceed
Steven Mosher:
That was my take on it too.
IMO, people who don’t know the answer to Q1 have a responsibility to answer the question themselves and to their own satisfaction, rather than foisting that responsibility off onto other people.
Obligatory reference to ‘The Devil went down to Georgia’.
==================
ya, once I discover the violin plot ( I think steve Mc used them once) I just
dumped the box plot plot, unless the data had outliers..
So I might start with a box plot, and then for presentation use the violin plot. And if the distribution is bi model all the better
The MET plot– is a mismash and they are able to hide the fact of comparing means to medians when the distributions are heavily skewed.
A Dirty little secret is that lukerwarmering is in one respect showing the violin plot and focusing on the median. or in other words, telling the truth.
‘The Devil went down to Georgia’
Why Georgia?
Heh, fiddling, R.
=========
Somethin’ about peaches.
Kim, I’d do it, but pasting lyrics is not as satisfying as karaoke.
> If you can do better on the test than you do at counting sentences we can proceed.
Not so fast.
However funnier can be to hint at robust statistics, that Moshpit acknowledges a misread question over there:
http://judithcurry.com/2013/09/14/nic-lewis-on-the-uk-met-office-on-the-pause/#comment-380033
might be nice before we pay due diligence to the lukewarm claim that medians provided truths in the specific case of estimating CS.
> IMO, people who don’t know the answer to Q1 have a responsibility [etc]
It is not anyone’s responsibility but Nic Lewis to argue that medians provided truths while means were vile misrepresentations, or something along those lines.
‘Not so fast.
However funnier can be to hint at robust statistics, that Moshpit acknowledges a misread question over there:”
Look a rat!
You asked Q1 and Q2. Answers were provided.
Now before you gallop away to another question we get to test.
Does willard acknowledge that his numbered question was answered?
can he count the parameters that define a PDF better than he can count sentences?
Can he admit that if a function is defined by say 5 parameters that specifying all 5 is better than only 2.
or does willard have some other counting logic he would like to argue is warraneted.
> Does willard acknowledge that his numbered question was answered?
Recount the questions, then recount the answers.
willard:
On advantages of median over mean as a robust central tendency estimator, when you have a skewed distribution, start here. It’s easily found and well known.
I suppose we all have different views coming from our different disciplines—as I see it, it is your obligation as a reader to familiarize yourself with these concepts. If it were an obscure point, difficult for me to substantiate on my own, I might agree with you over the need for the author to substantiate his work.
This is a rather trivial point though, easily checked. You not being an expert in statistics doesn’t suddenly make it somebody else’s responsibility to educate you.
Please leave the mansplaining to Moshpit, Carrick. You’re basically implying that climate scientists like Isaac Held, who can write papers in which the word “median” does not occur and that even Nic Lewis cite, should learn more about medians, because if they did they would some kind of lukewarm light. I find this unconvincing.
Nic Lewis claims that using medians (among other things, but that seems his main object) provides “a better idea of the distribution of probability”.
His argument to that effect is lacking.
Willard I pointed out a readily obtainable link explaining the advantages of median over mean. I then gave my opinion, being careful to focus it on my own discipline. It’s churlish on your part to dismiss either of these as “mansplaining”
As to the quote, the full quote in context is:
This refers to the figure not to the use of median. It is an obvious point to anybody with a mote of statistical training.
If you don’t understand the point, there’s a cure. Learn some stats.
Edit:
It’s easy to demonstrate that a few outlier points (meaning low-probability here, not erroneous) that the mean will be more substantially affected by these “outlier” points than the median.
(Sorry wrong subthread.)
> This refers to the figure not to the use of median. It is an obvious point to anybody with a mote of statistical training.
And yet the revised figure 1 shows medians instead of means. One of the revisions of this figure was the use of medians instead of means for the model studies. The other two points were to reclassify one study and to insert an estimate based on his favorite decade.
You’re only way to back up your claim would be to tell us how only Nic Lewis’ two last point bears on a better idea of the distribution of probability. In other words, you have to show that Nic Lewis speaks of distributions of probability without referring to his newly added medians. Surely you are joking, Mr. Carrick!
While it may work at Lucia’s or Jeff’s, one does not simply use parsomatics to get to Mordor.
I authored that last comment, which was made under my WP login Id.
‘AOS models are therefore to be judged by their degree of plausibility, not whether they are correct or best. This perspective extends to the component discrete algorithms, parameterizations, and coupling breadth: There are better or worse choices (some seemingly satisfactory for their purpose or others needing repair) but not correct or best ones. The bases for judging are a priori formulation, representing the relevant natural processes and choosing the discrete algorithms, and a posteriori solution behavior.’ http://www.pnas.org/content/104/21/8709.full
Pekka’s idea of models is fundamentally incorrect. Ultimate precision is well beyond us – and uncertainty in data, parameterizations and coupling create structural instability in the models.
‘Lorenz was able to show that even for a simple set of nonlinear equations (1.1), the evolution of the solution could be changed by minute perturbations to the initial conditions, in other words, beyond a certain forecast lead time, there is no longer a single, deterministic solution and hence all forecasts must be treated as probabilistic. The fractionally dimensioned space occupied by the trajectories of the solutions of these nonlinear equations became known as the Lorenz attractor (figure 1), which suggests that nonlinear systems, such as the atmosphere, may exhibit regime-like structures that are, although fully deterministic, subject to abrupt and seemingly random change.’ http://rsta.royalsocietypublishing.org/content/369/1956/4751.full
The situation is shown schematically here. Each independent solution is feasible – and the range of feasible solutions remains unknown.
http://rsta.royalsocietypublishing.org/content/369/1956/4751/F8.expansion.html
If we understand James McWilliams in the top quote properly – there is no necessity for models to ‘run hot’. Merely bias in the subjective assessment of plausibility of the one possible solution.
The alternative is to evolve pdf’s from perturbed physics models. Even there the prediction of ‘climate shifts’ remains an utter impossibility – and therefore we should expect divergence of climate and models over the rest of the century.
‘Q2. What does showing a better idea of the distribution of probability even mean?”
well, since a PDF is defined and delimited by key metrics, showing more of those metrics gives you a better idea of the PDF.
lets do an example.
Suppose willard takes an intelligence test 100 times.
His scores range from 0 to 100, where 0 is total idiot and 100 is genius.
If a draw a bar from 0 to 100 I have only shown you ONE parameter of the PDF.
Now suppose I show you a bar like MET does, where 95% of the measures are between 5 and 95. Now I’ve shown you a second metric of the PDF.
But look at the ways this can happen.
Willard could have 5 scores at 0 and 45 scores of 5, and 45 scores at 95
and 5 at 100.
Or he could have 5 score of zero, 1 score of 5, and 89 scores at 95, and 5 at 100. That would be a totally different PDF although two metrics would be identical.
So we want to know the shape. is it uniform across the range? peaked?
double peaked? is it SYMETRICAL about some value, or skewed, is it platokurtic or leptokurtic.
To get this added information we want to know the shape OVER THE RANGE. and we want to know the measures of centrality. if the mean equal to the median? or is it skewed.
Lets suppose his tests are uniform. he gets 34 scores of zero, 33 of 100 and 33 at 50. Now imagine that instead he gets 100 scores at 50.
So a better idea of the PDF is one that shows more of the information that determines the PDF. Its one that reduces the uncertainty in the readers/viewers mind. The uncertainty in a PDF is governed by its moments. When you show all the moments you have conveyed all the information bits. A better idea is one that shows all the bits.
> So a better idea of the PDF is one that shows more of the information that determines the PDF.
Illustrating centrality does not answer how using medians instead of means would show more information that determines the PDF in our specific case.
Medians abstract away weights. There may be problems where weights may matter more than protecting one’s judgement against outliers, e.g Backgammon, Scrabble. Even outliers may provide information when estimating risks.
I don’t think we should interpret runs as potentially erroneous data points. Unless misspecified, model runs do not simply go beyond the problem space to reach Mordor. Oh, but look which kinds of studies use medians and which kinds are using means…
***
If medians do provide more information about the estimators of CS, an argument should be made to that effect. If the argument has already been done, it should be cited. And this argument should also apply to measurements.
Interestingly, Nic does seem to appreciate the use of means in that context:
http://julesandjames.blogspot.ca/2013/02/a-sensitive-matter.html?showComment=1359934687386#c2125990923736360156
Wow, you’ve really managed to butcher this…
The observation is that median is a more robust central tendency estimator than mean:
This relates to samples of a population associated with a given PDF. One useful metric of a PDF is the “mode”, the most probable value in the distribution.
In distributions that are symmetric (not climate sensitivity PDFs), the mean equals the median equals the mode. In distributions that are not symmetric (have nonzero skew), the median is closer to the mode than the mean.
A simple example of this is the Rayleigh distribution. For sake of simplicity, let’s set sigma = 1. Then,
PDF(x) = x * exp(-x^2)
mode = 1 [solve PDF'(x) = 0 => x = 1]
median = sqrt(2 * log(2)) ≈ 1.17 [solve CDF(x) = 1 – exp(-x^2/2) = 1/2]
mean = sqrt(pi/2) ≈ 1.25 [integral(x* PDF(x), {x, 0,infinity) = sqrt(pi/2)]
Secondly, if we have a small sample of points, it is easy to demonstrate that the median is a more reliable estimator of this central tendency of the distribution than the mean for distributions with long tails (the PDFs associated with climate sensitivity are a nice example of this). It’s easy to demonstrate that a few outlier points (meaning low-probability here, not erroneous)
If the number of points in the sample is large, there isn’t much difference in terms of the reliability of the statistic. But the argument favoring median over mean has nothing to do with “potentially erroneous data points”, just distributions that have long tails.
That said nobody, including Nic, argues that mean is useless. The example you raise relates to his paper. An explanation is give on why he used means in his paper: to compare to other papers that only provided means. Another is to avoid confrontation with people like yourself, who seem more interested in attacking him than in admitting the narrow scope of your own knowledge of statistics.
It’s easy to demonstrate that a few outlier points (meaning low-probability here, not erroneous) that the mean will be more substantially affected by these “outlier” points than the median.
The important point to remember is that for fat-tailed distributions that are integrable, the