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chris at 02:10 AM on 13 July 2010Hotties vs Frosties?
Ken Lambert at 00:07 AM on 13 July, 2010 Interesting, Ken. That illustrates quite a lot about certain approaches to science and knowledge, and especially efforts to misrepresent by focussing on minor areas of uncertainties. This entire thread started with a statement about context, and that (i.e. an informed consideration of context) would help you to understand, for example, the OHC measurement you refer to here: "One wonders why we bother with measurements which give 0.8mm +/-0.8mm as evidence for SLR consistent with OHC rise." Remember that that measurement was part of an analysis of the extent to which the sea level "budget" could be closed for a very short four year period [*]. Not surprisingly estimation of some the sub elements of this analysis (e.g. the thermosteric contribution to sea level) has a high uncertainty. That's obviously why we don't attempt to draw fundamental conclusions from analysis of very short time periods. What is the context in which it might be useful to determine an estimate of the thermostatic contribution at low precision, to a very short term period of sea level rise Ken? The answer is during a period following the introduction of new measurement technologies (ARGO for upper ocean heat measurement; GRACE for gravity perturbation based mass redistribution measurements). These analyses constitute an important initial test of the technologies and allow us to establish whether fundamental problems might exist (crudely put, if the sum of GRACE-derived mass contributions and ARGO-derived thermosteric contributions to sea level rise including error at 95% confidence overlaps with independently determined satellite-derived sea level rise, then we have confidence that there is nothing fundamentally problematic with the technologies and methodologies, although that doesn't prove that everything is working as well as we hope). So context is key. Obviously over the longer term the precision of our measurements improve (signal rises from noise as random measurement error and internal fluctuations average out). This (context) is where there are problems in your other statements: Peter: "each piece of evidence should be able to stand on its own right, irrespective of any support that may or may not come from another domain" (#40)." Ken: "That is a profound statement of scientific truth." Well it certainly sounds profound Ken, but I suspect it may be one of those rather empty assertions that dissolve away when considered in the light of real world observations. Can you give us a relevant example? For example one in the context of the current discussion. "When an accurate and repeatable measurement of OHC is available, then we will know the true extent of global warming or cooling." There's no question that good OHC data will fundamentally improve our ability to test our understanding to the Earth response to radiative imbalance. But global warming can also be defined in relation to the response of the Earth surface and since (a) this is the bit of the Earth we inhabit and have a profound interest in, and (b) this is the measure that allows us to assess the relationship between changes in radiative forcings and surface temperature response in the near and deep past, it would be foolish indeed to consider that we require OHC measures before we can properly assess global warming. Remember that uncertainty in little bits of sub issues doesn't drive out certainty in the more fundamental areas of our knowledge. For example we have high confidence that radiative imbalance results in sea level rise due to land ice melt and ocean warming. We can measure sea level rise reasonably well and the measurements generally correspond to our expectations. The fact that we can only make an imprecise direct estimate of the thermostatic contribution to sea level rise during the period Jan 2004 to Dec 2007 doesn't negate our higher level certainties. [*] Leuliette E, Miller L. 2009. Closing the sea level rise budget with altimetry, Argo and GRACE. Geophys. Res. Lett. 36:L04608 -
Albatross at 02:08 AM on 13 July 2010Hotties vs Frosties?
Ned, Phillipe et al., BP has repeated this figure on this thread, even though John Cook advised him here that he is comparing OHC for 0-3000 m with that from 0-700 m. That is not a valid comparison, and definitely not a valid reason to strongly assert that there are issues with the data. Someone else claims that "why we bother with measurements which give 0.8mm +/-0.8mm as evidence for SLR consistent with OHC rise" Correct me if I am wrong but the trend in global mean sea-level rise is 3.0 mm/yr +/-0.4 mm/yr from Uni. Colorado. Or are they referring only to the contribution from thermal expansion? I am all for people making the effort to understand and even to try and reproduce scientific findings. However, when our results do not agree with those in the literature, I would caution against making statements of data fudging or conspiracies. A much, much more plausible scenario is that we have made one or more errors. -
Riccardo at 01:37 AM on 13 July 2010Sea level rise is exaggerated
daniel, I'd not look for cutting edge research paper, it's just simple physics. Global sea level may rise due to thermal expantion of the ocean or to the melting of land ice; locally it may rise for a change in the ocean circulation pattern. It has nothing to do with AGW and the like. Add to this that even simple statistics would tell you that going from the lower to the higest end of the uncertainty range is statistically very unlikely. Beyond this, I might we willing to say that global sea level rose because of a rise of the ocean floor with respect to the continental crust or because of a giant movent of masses that locally produced an increased gravitational pull. In principle they are both possible, in practice they're both untenable. And this is also the line we should never cross if we want to talk about the science of any phenomenon instead of producing pseudo-scientific hypothesis. -
michael sweet at 01:32 AM on 13 July 2010Hotties vs Frosties?
Ken Lambert (and others) Your post at 102 suggesting that we do not know the extent of global warming because of uncertainty in OHC is extraordinary!! The claim that we must have every piece of the puzzle exactly in place in order to understand what the picture is has been used for decades by deniers to argue that we should not take action about global warming. In the 1990's they said that we needed to know surface warming. Look at Watt's pictures! Forget the confirming satalite data. Now that surface warming is known beyond resonable doubt (as described above by Ned) the deniers want OHC. Once that is known they will want advance, certain knowledge of sea level rise, confirmed prediction of all rain changes or some other obscure item. It will never be enough. "each piece of evidence should be able to stand on its own right, irrespective of any support that may or may not come from another domain" (#40). What a waste of space. Some data will never be as sure as other data. OHC is very difficult to measure and will have uncertainty for decades. It is the combination of mulitple lines of evidence that is convincing. How many times has John said that we must look at ALL the data and see the whole picture, rather than focus on a single uncertain item and say that is more important than all other data combined. -
ProfMandia at 01:04 AM on 13 July 2010Must-read article on ocean impacts by ocean scientists
Two more links from these two scientists written for the general public: John F. Bruno: The Impact of Climate Change on the World's Marine Ecosystems Ocean changes may have dire impacts on people - UQ News Online - The University of Queensland Scott A. Mandia, Professor of Physical Sciences Selden, NY Global Warming: Man or Myth? My Global Warming Blog Twitter: AGW_Prof "Global Warming Fact of the Day" Facebook Group -
PatriciaW at 00:56 AM on 13 July 2010Must-read article on ocean impacts by ocean scientists
It is unfortunate that the authors of this article still repeat the long since abandoned target of under 450ppm. They also do not mention the effect on the planet's oxygen supply which ocean acidification will probably cause if it kills off oxygen generating phytoplankton. (I've also added this comment to the original article.)Response: Re oxygen, I'd hazard to guess John and Ove were doing the same thing I tend to do with my articles lately - hit the broad points and let the nitty gritty come out in the comments. In science writing, it's tempting to throw everything in there but effective communication requires you discipline yourself to the major points lest your message get diluted with too many details. -
daniel at 00:16 AM on 13 July 2010Sea level rise is exaggerated
Riccardo at 00:00 AM on 13 July, 2010 Well actually I would question whether your claim that SLR is so strongly linked to the percieved warming of the 20th century or if the temperature record is so reliable into the past, both over this period and beyond. But since this is a pro AGW website it is up to people like myself to disprove the unproven. Are there any papers you rely on Riccardo to undoubtedly satisfy yourself of SLR driven strongly by climatic factors and also the reliability of the reconstructed temperature record? Post a link and we'll discuss it. I've only just started to find some time to read some of Peter's links throughout the above discussion.Response: Might I suggest starting with Vermeer 2009 that examines the link between sea level rise and temperature, finding the two are closely linked:
Observed rate of sea-level rise (red) compared with reconstructed sea level calculated from global temperature (dark blue with light blue uncertainty range). Grey line is reconstructed sea level from an earlier, simpler relationship between sea level and temperature (Vermeer 2009).
Of course, where the paper gets really interesting is when it uses these results to predict future sea level rise which we examine here... -
Ned at 00:11 AM on 13 July 2010The Dunning-Kruger effect and the climate debate
Mr_Obvious, it would help if you'd give some specifics -- when you just write "[t]he various posts above seem to abound with seemingly objective; but, in many cases, clearly slanted view points" it's difficult for anyone to respond meaningfully. Which post seems slanted, and how? The one specific fact you mention in your comment is By the way, something I noticed long ago, and posted on on a number of forums; but, have get to get a well validated response to: O2 and CO2 have nearly the same IR absorption spectra / levels. Why is O2 not considered a green house gas when CO2 is? I'm not sure where you are getting that from, but the absorptance spectra of CO2 and O2 are entirely different. Check out the bottom panel of this figure:Note the CO2 absorptance peak ~13+ micrometers, within the range where the Earth surface radiates and the atmosphere is otherwise semi-transparent.
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Riccardo at 00:10 AM on 13 July 2010Temp record is unreliable
Ned, sometime I think that whatever the amount of data one can provide there's no way to convice some, hopefully just a few, guys. Nevertheless, it's always worth trying and keep all of us up to date with these new findings. Thanks. -
Ken Lambert at 00:07 AM on 13 July 2010Hotties vs Frosties?
BP, JMurphy, kdkd "each piece of evidence should be able to stand on its own right, irrespective of any support that may or may not come from another domain" (#40). That is a profound statement of scientific truth. I have found BP's contributions very informative and obviously backed by a serious amount of work. I agree with much of his analyses. The OHC issue is critical to the whole theory of AGW by the enhanced CO2GHG effect. One wonders why we bother with measurements which give 0.8mm +/-0.8mm as evidence for SLR consistent with OHC rise. When an accurate and repeatable measurement of OHC is available, then we will know the true extent of global warming or cooling. -
Riccardo at 00:00 AM on 13 July 2010Sea level rise is exaggerated
daniel, step by step things are getting clearer in my opinion and your last graph is very helpful. Now, in light of this new graph, could you tell what should drive these sudden accelerations in the past? Known science can tell just for the last one, the one in the last century, it's mainly ocean thermal expansion and land ice melting. It's up to who's trying to cast doubts on the accepted explanation to provide evidence and reconcile it with other data that support his hypothesis. -
Ned at 23:04 PM on 12 July 2010Hotties vs Frosties?
I admit I haven't been following this thread, partly because I've been traveling and partly because I'm not all that interested in these kinds of "meta" discussions. But I was surprised to discover that Berényi Péter is still making incorrect allegations like this: Furthermore, there is the (not well advertised) issue of different adjustment procedures being applied to US data and the rest of the world. The differences in processing between the USHCN and non-US stations in GHCN are discussed in many places, including in the primary description of the GHCN v2 data set, right here: Peterson, T. and R. Vose. 1997. An Overview of the Global Historical Climatology Network Temperature Database. Bulletin of the American Meteorological Society, 78(12): 2837-2849. Less than two weeks ago I pointed this out to BP in another thread, where he was discussing the same issues: Are surface temperature records reliable? I suppose he must have stopped following the discussion there and then decided to bring it up again here. In any case, it is completely wrong to suggest either that the GHCN data are "tampered with" or that the difference in adjustments between USHCN and GHCN is "not documented" (his emphasis). He appears to have never bothered to read even the basic introductory paper about GHCN (Peterson and Vose 1997) before flinging around accusations of "tampering". I would urge people to go back and reread the discussion of this issue in the previous thread. I'd also urge people to keep the following in mind: * The net effect of the GHCN adjustment is small, slightly increasing the trend in the early 20th century but actually decreasing the trend over the past three decades. As I wrote in the other thread: Using a gridded analysis, the actual difference in the trends is 0.04 C/century over the last 90 years. Over the last 30 years, the difference in trend between the raw and adjusted data is 0.48 C/century ... with the adjusted trend being lower than the raw trend. In other words, the "tampering" that BP has detected is, over the past 30 years, reducing the magnitude of the warming trend. * The unadjusted data are available and can be (and are) used in many of the new, independent temperature reconstructions. * You cannot evaluate the actual effect of the GHCN v2 adjustments on the global temperature trend without using some form of gridding or other method to compensate for spatial dependence in the adjustments themselves. Again, as discussed in the other thread, Treating the rest of the world as homogeneous will not yield an unbiased estimate of the global mean adjustment unless either (a) the stations are distributed approximately uniformly in space [and] time, or else (b) the expected value of the adjustment for station X in year Y is independent of that station's location. * Land represents only 29% of the earth's surface, so any artifacts present in the GHCN data (due to adjustments, UHI, or anything else) will have only a small impact on the global trend as a whole. * Finally, surface temperature analyses using GHCN (whether adjusted or not) are generally similar to those based on satellite measurements of the lower troposphere. In addition, a new analysis by Ron Broberg and Nick Stokes shows that the GHCN temperature trends are virtually identical to those from a completely different surface data set based on GSOD. The GSOD data include a larger number of stations, better coverage of the Arctic and other remote regions, and no decline in station numbers in recent years. At this time, there is really very little point in arguing about the surface temperature trends. They've been confirmed over and over again; none of the various criticisms leveled at them has been shown to have any substantial impact at all on the final outcome. -
JMurphy at 23:04 PM on 12 July 2010The Dunning-Kruger effect and the climate debate
Mr_Obvious wrote : Hanson was a good example of having credentials, being well respected, and getting it wrong, repeatedly. Well, that statement may seem like an obvious fact to you but could you at least back it up with some examples, please, for those of us who don't just accept that claims are the same as facts ? -
Mr_Obvious at 22:37 PM on 12 July 2010The Dunning-Kruger effect and the climate debate
Just an after thought follow up. Credentials do not in and of themselves guarantee wisdom, understanding, or even an applicable skill set. Hanson was a good example of having credentials, being well respected, and getting it wrong, repeatedly. Gore can be more easily written off as he has no real credentials; yet, Hanson was just as far off as Gore, who based his movie - in part - on Hanson's predictions. -
Ned at 22:24 PM on 12 July 2010Temp record is unreliable
Ron Broberg and Nick Stokes have created an entirely new gridded global surface temperature analysis that is independent of GHCN. It is based on the Global Summary of the Day (GSOD) records for a very large number of stations, available here. The main advantage of this is that it provides a semi-independent confirmation of the GHCN-based analysis that has been used for most of the surface temperature reconstructions up to this point. Other advantages include a larger number of stations, more stations in the Arctic and other remote locations, and no decrease in station numbers in recent years. Ron developed tools to acquire and reformat the GSOD data, and Nick then ran it through TempLS, his global temperature analysis program. The results are very similar to those from previous reconstructions using GHCN:Over the past three decades, both data sets (GHCN and GSOD) show similar trends (+2.5C/century) in Nick's analysis. If you find this all a bit confusing, the bottom line is that this is a radically new way of confirming the reliability of the existing surface station temperature analyses from GISSTEMP, HADCRU, etc.
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Mr_Obvious at 22:22 PM on 12 July 2010The Dunning-Kruger effect and the climate debate
It seems The Dunning-Kruger effect is alive and well on both sides of the debate. And the CO2 levels remain an example even now, and to, at least some extent, perhaps, may even be effecting the author of this article. The various posts above seem to abound with seemingly objective; but, in many cases, clearly slanted view points. In nearly every post (including the article) some, often obvious, detail was omitted that might have impacted the conclusion. Perhaps we could all take some extra time to refine our thoughts and triple check our facts before posting. By the way, something I noticed long ago, and posted on on a number of forums; but, have get to get a well validated response to: O2 and CO2 have nearly the same IR absorption spectra / levels. Why is O2 not considered a green house gas when CO2 is? (If your planning on making the narrow band argument, please have something verifiable to back it up) -
CBDunkerson at 22:09 PM on 12 July 2010Hotties vs Frosties?
Geo Guy #94 wrote: "...and yet we can emphatically state that AGH's [sic] are THE driver to rising global temperatures??...I think not." 'THE' only driver? No. 'THE' most significant driver? Based on both the paleoclimate record and measurements of current warming I don't see how anyone can dispute it. We can see from the paleoclimate record that major warming and cooling shifts have continuously corresponded with GHG shifts. We can measure GHG and radiation changes and compute (not guess, not model, not estimate... but compute from proven values and formulae) that they account for most of the measured warming observed thus far. In short, we know that CO2 is the primary driver of current warming because we can do math; Even most 'skeptics' now seem to accept that a doubling of CO2 by itself would cause about a 1 C (actually just under) increase in global temperature... this is computed from the measured radiation absorption spectrum of CO2 and the formula Arrhenius came up with over a century ago. If that is taken as accepted, as all but the extreme fringe of skeptics seem to agree, then we can compute expected 'GHG only' warming for other CO2 levels; In 1998 the CO2 level was 365 ppm, but with changes in other GHG levels factored in the 'CO2 equivalent' was 412 ppm. The historical level generally used is 278 ppm. Thus, IF 'x*ln(576/278) = 1 C' (i.e. 1 C increase from CO2 doubling) THEN, 'x*ln(412/278) = 0.57 C' The measured warming through 1998 was about 0.75 C above what it was back when GHGs were at 278 ppm. Thus, 76% of the observed warming can be explained by the warming we know the increase in GHGs should have caused. That makes GHGs the primary (76%) driver of the observed warming... and the remaining 24% shows that feedback effects have been positive, not negative. We only then get into models with the expectation that feedback effects will accelerate as time goes by and estimating the end result. This is why you no longer find 'skeptic' scientists claiming warming of less than 1 C for a doubling due to negative feedbacks... we KNOW net feedbacks are positive. The only remaining refuge of 'skepticism' is that these net positive feedbacks will be less than the majority of scientists believe. Disclaimer: The math above is greatly simplified in that it computes temperature anomalies directly rather than radiative forcings and then the temperature anomalies those would cause AND ignores changes in atmospheric density as composition changes (which would only be significant for MUCH greater atmospheric changes than we are looking at and would then lead to MORE warming). That said, it's precise enough for illustrative purposes... most of the observed warming is due to GHG increases. -
Berényi Péter at 20:31 PM on 12 July 2010Hotties vs Frosties?
#87 Philippe Chantreau at 01:44 AM on 12 July, 2010 The point was not about the data, it was about your attitude. Stop ranting about my attitude, please and let's focus on data instead. If you show my reasoning to be faulty by uncovering the specific error, I am quite ready to accept it. On the other hand if you try to find flaws in my attitude, that gets us nowhere. BTW, your attitude of surmising an error is something to be ashamed of instead of to be corrected is highly questionable. At least I refuse to take this attitude as a valid and fruitful one. What about actually doing some work by trying to understand things on your own? It would have the advantage of promoting public understanding as well. -
daniel at 20:01 PM on 12 July 2010Sea level rise is exaggerated
To Riccardo #89 Ok Riccardo again I'l answer a bit more directly. Do we have any real evidence that the 1mm/yr trend existed without short term variations from the paleo data? How can we know if drivers existed or not when the links of SLR to temperature fluctuations are so poorly achieved using paleo data? What do other data sets say Riccardo? Post some links we can discuss it. Here's a graph of Donnelly's data with sample 11 reassigned to the younger date range which was never adequately constrained by Donnelly in the first place. (But he was happy to fit the older date range to suit his trend).Are you sure it's not possible for the recent sea level trends, or very similar slightly less severe uptrends, to have existed in the past given the uncertainty in the paleo data? Does this make the recent uptrend look less alarming? Is all of pro AGW science done this way? You wanna discuss drivers? Post some links.
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MP at 18:37 PM on 12 July 2010Hotties vs Frosties?
John Brookes @ 96 “Thanks for the comments. I don't favour delay. I would like to see a carbon tax implemented now, and steadily increased. Only if the weight of evidence starts to turn, would I want the carbon tax to be removed.” One has to question whether this is the most appropriate and robust strategy in terms of being applicable to more than one possible scenario. In this regard, it would appear that the different possible scenarios for climate change that have been advanced by various interest groups can essentially be simplified as being: 1. Continual warming with no prospect of a further glacial period; 2. Warming in the short to medium term before the onset of cooling that precedes a new glacial period; 3. Temperature equilibrium in the short to medium term before the onset of cooling that precedes a new glacial period; and 4. Cooling in the short term to medium term preceding the onset of a new glacial period. Both continual warming and the onset of a new glacial period in the future will have a significant impact on the sustainability of the human population which is already being impacted by a shortage of resources, particularly food, water and energy, to even meet basic needs let alone the lofty goals of narrowing the disparity in global living standards which is becoming an increasing source of conflict. Based on the premise that GHGs are contributing to warming, it is evident that attempts to control one of one of these gases, CO2, via the suggested further carbon tax (carbon taxes already exist, i.e in many countries petroleum products are currently heavily taxed) is only applicable to addressing scenario 1, as the impacts from another glacial period outlined in scenarios 2 to 4 could be beneficially mitigated by the warming afforded by GHGs. In addition, within the context of the dynamic natural processes affecting both the earth and the universe, as no one appears to have been able to accurately determine the appropriate level of CO2 in the atmosphere for the earth’s current and future situation, one must pose the question, what happens if we get it wrong and we create a reverse tipping point by reducing too much CO2 and accelerate the onset of the next glacial period? Within this context, the most robust strategy that is able to respond to the four possible scenarios of climate change and the inability of the earth’s resources to currently provide every human being with a globally accepted living standard, sadly remains placing limits on population growth. It is contended that this strategy could even be more effective in reducing CO2 than the proposed carbon tax due to the cumulative impact of a reduction in the demand for goods and services and governments would still have the option to review and relax controls to order to respond to changing circumstances in the future, and even increase CO2 emissions to mitigate the effects of a new glacial period should the weight of evidence suggest this to be necessary and appropriate. Finally, just as the Stone Age ended, not because the earth ran out of stone or a stone tax was introduced, the carbon age will end because humans will find more appropriate or cheaper alternative sources of energy rather than being subject to further arbitrary carbon taxes that generate revenue that is more likely to be used to try and address sovereign debt rather than facilitate the research and development of alternative sources of energy. -
JMurphy at 17:57 PM on 12 July 2010Hotties vs Frosties?
Geo Guy wrote : As scientists we must continually question the “status quo”. If we stop doing so, our understanding of science will cease to evolve. Hence despite what the “science” may tell us, there is a definite role for taking a contrarian position. Science is rarely definitive. The application of science is what changes over time and is the basis upon which we evolve as a species. So, Creationism (which continually questions the status quo, takes a contrarian position and likes to show that the Theory of Evolution is not definitive) is a valid position to take, is it ? Perhaps the answer lies "somewhere in the middle" - we're not talking about "irrefutable proof" after all, are we ? -
daniel at 16:33 PM on 12 July 2010Sea level rise is exaggerated
Riccardo at 16:26 PM on 12 July, 2010 You tell me. Donnelly can't. -
Riccardo at 16:26 PM on 12 July 2010Sea level rise is exaggerated
daniel, here the discussion becames circular and I can only repeate what i wrote in #78. Do we have any evidence of such "short" (one century and a half) term variations in the past or are they just hypothetical? What should have produced these accelarations? What do other datasets say? -
John Brookes at 14:37 PM on 12 July 2010Hotties vs Frosties?
owl905 @79 - Thanks for the comments. I don't favour delay. I would like to see a carbon tax implemented now, and steadily increased. Only if the weight of evidence starts to turn, would I want the carbon tax to be removed. I do favour civilized debate. As I said in a comment above, there is no point in assuming that people with opposing views to your own are arguing in bad faith. Some are, but you won't sway them. Rather than polarise people into the two camps of hotties and notties, I'd like to think that there is a third camp who are more interested in finding out exactly what is going on. There is of course a 4th camp, by far the biggest, which is people who don't know, and are smart enough to know they don't know, and who will leave it to others to work it out. These people will decide elections and policy. I think it is unwise to tell such people, "If you aren't with us you are against us". Faced with a perceived need to take sides, they might go all notty on us. For these people, the precautionary principle (you could take a chance and bet that all those scientists are wrong...), together with reassurance that the change to a low carbon economy will not be the end of the world as we know it, should be enough to see them support action. Trying to "prove" that global warming is real and dangerous could be counter productive. If they have kids, they might like to think of their future - after all, parents will happily incur the large financial penalty of private schooling in the hope that their kids will have a better life. A much smaller investment in the environment would seem like a sensible thing to do. -
scaddenp at 14:22 PM on 12 July 2010Hotties vs Frosties?
geoguy - the point about drivers is not that we know them but that you cannot have proof in science. Testing models against data is at the heart of science. I really dont know how else you pursue the subject. (Not that I think anything "new" about cosmic radiation or ocean currents has changed any picture of the earth heat budget). The models are very good at not only predicting temperature but also the pattern of warming - and they spring from a basic physics. A conclusion that 3.7Wm/2 of radiative forcing is NOT going to cause warming requires some as yet undiscovered negative forcing. Is this measurement of GHG forcing not direct enough for you? Oh and models in the scientific sense ARE the theory. The computersdo the numerics for the model. If comparing their prediction to data is not the way to test the model, then what is? I am not really sure what point you are trying to make with the Jun paper. But for further analysis on the use of model ensemble, see Annan et al "Consequently you have every reason to reject the model if you are wanting to come to a specific conclusion. " This statement just does not make sense. Please lets hear your alternative theory of climate that is making better predictions. Some numbers not hand-waving would be good. -
Geo Guy at 13:38 PM on 12 July 2010Hotties vs Frosties?
scaddenp - # 91 - knowing the drivers is one thing; knowing completely how they interact with one another to affect our climate is another. We are learning new things about our sun each day, the sun that sends the heat to earth. We are also learning new things about cosmic radiation and how it affects our climate. We know that ocean currents are a big determinant of climate yet we do not fully know to what extents. We know that episodes of el Nino and el Nina have profound effects on global temperatures yet we do not fully comprehend how those episodes occur...and yet we can emphatically state that AGH's are THE driver to rising global temperatures??...I think not. Models tend to have their own built-in bias. http://www.stat.tamu.edu/~mjun/paper/A06624R1.pdf Furthermore models are only as good as the input parameters, including the interaction of parameters that drive our climate. Models are not proof of a theory, only evidence how the theory may act under specific parameters. Consequently you have every reason to reject the model if you are wanting to come to a specific conclusion. -
johnd at 12:51 PM on 12 July 2010An account of the Watts event in Perth
JMurphy at 08:12 AM, the correct terminology should probably have been "reappeared" as technically I understand they first "appeared" in Perth enroute to their scheduled presentation at Narrogin the previous day. It's a small point but in the spirit of the precision being demanded, perhaps a valid one. ;-) -
daniel at 12:31 PM on 12 July 2010Sea level rise is exaggerated
Peter Hogarth at 02:15 AM on 12 July, 2010 "No, you have not said this until now." Pretty much what I've been saying the whole time Pete. Sure it's a different approach but what I'm saying should have been obvious from the very beginning. "What you have argued is that extending the approx 1mm/year long term linear trend from pre-tide gauge data beyond 1856 by including point 1 gives a 1.2mm trend and error bars which can fully accomodate the total tide gauge data record anywhere inside this trends error envelope," No not anywhere. For instance it is unlikely to have occurred between 1700-1850 but there is no evidence to suggest it couldn't have occurred between 1300-1700. "Your case for including point 1 in an overall 1.2mm trend is invalid. Clearly, the density of tide gauge data makes any influence of point 1 marginal on the measured 2.8mm/yr trend since 1856, clearly, the recent measured trend is diverging away from the long term paleo trend." Uh huh.... but the divergence is covered by the uncertainty of modern sedimentary data. Sedimentary data that lies on a 1.2mm/yr 700 year trend. Hmmmmm.....invalid? Maybe, I dunno, highly relevant? "That point 1 error bars overlap the tide data possibly validates point 1, but the fact that the tide gauge data overlaps point 1 does not validate extending the pre-1856 trend." Why? Too inconvenient a fact for you? "Point 1, statistically speaking, is on this trend." It is also.... statistically speaking...... on the 1.2mm/yr trend. Therefore so is the tide gauge data. Statistically speaking of course...... "It is not the same as a linear trend. It is likely that the envelope will follow or at least accomodate whatever the true trend was. We can only ascribe a probability to this." Amen brother, finally we agree on something. "It is barely possible to fit the tide gauge data into the 2 sigma envelopein one pre 1800 place,...." Mere opinion, show it with an overlay. "...but it is not a "good" statistical fit anywhere over any approx 150 year period except after 1800 (by comparing with at least three paleo points, though this is not a strong test)." Which is why Donnelly's paleo data is insufficient for a valid comparison to tide tide gauge. He doesn't have the resolution let alone the certainty. "It is not possible to fit inside the 1 sigma envelope anywhere,..." Mean height of paleo sample 1 has tide gauge lying over 95% (2 sigma) confidence interval extreme. Care to retract? "...and the data series deviates away in opposite directions above and below the envelope, indicating significant systematic trend error." Perhaps only if compared to an irrelevant long term trend on the short term scale. An overlay to help make your point? "I repeat that your suggestion is possible, but not "likely" from this data." Simply not shown at all. On the short term, with the data we have, it's just as likely. "Of course we need a reality check, and the temperature record and other work I referenced strengthens the case presented in the paper, and further weakens your hypothesis" I think what you'll find pete is that if you apply my kind of reality check to all that supportive evidence you will find the AGW hypothesis severely weakened. You can't support poor data and conclusions with more poor data and conclusions. If you can't see the error here you can't thoroughly critique the mass body of evidence you claim is out there. Peter Hogarth at 03:52 AM on 12 July, 2010 Please provide the graph with the relevant data then and provide me with your source so I can also provide graphs of a similar nature. -
Rob Painting at 12:15 PM on 12 July 2010Hotties vs Frosties?
BP @ 84, so it's just speculation on your part?. -
daniel at 11:46 AM on 12 July 2010Sea level rise is exaggerated
Riccardo at 06:08 AM on 12 July, 2010 Yes, it tells me that short term variations are quite possible within the paleo data set. It is verified by the highly deviant tide gauge results still lying within the uncertainties of the modern sedimentary data. -
scaddenp at 11:01 AM on 12 July 2010Hotties vs Frosties?
BP. "Legitimate adjustments necessitated by instrumental bias simply can't look like this" Why not?? I cant really imagine how you would expect such a graph to look without a very deep looking at station procedures and changes. We had a similar argument about NZ stations - screams that "adjustments" were being made to give more warming. You cannot resolve these without looking at the individual stations that are supposedly adjusted wrong. NIWA published details on adjustment cases where it was high. eg Hokitika and also showed the trends for the record for those stations that had no moves at all. NZ Temp Record Your arguments about the temperature record are empty till you can show the adjustment is wrong - or publish a better way to adjust the record. I am disappointed that you have declined to discuss the consilience issue - what do you the chances are that there are systematic errors in the independent records for sealevel, glacial volume and temperature that will somehow make AGW go away? I am all for skepticism and close examination of the science so long as you also acknowledge the weight of evidence and recognize that we are very likely facing a serious problem. Public policy cant wait on perfect science. -
scaddenp at 10:49 AM on 12 July 2010Hotties vs Frosties?
Geoguy - This "since my model predicts what I see, therefore my interpretation of what I see is correct” is I think a complete mis-characterization of the argument. How do you know why havent found all the drivers for climate? Answer - you can never know. Proof is impossible in science. However, what you have to do with models all the time is make predictions from them and compare to reality. Every time you get you right, it improves the confidence. The correct characterisation is more like "since my model predicts what I see, I have no reason to reject the model”. Now tell my what alternative theory of climate that you like that can make that statement? -
Philippe Chantreau at 10:00 AM on 12 July 2010Hotties vs Frosties?
Albatross, my comment referred mainly to the acidification post. I would have thought that BP would not so quickly reiterate accusations in another thread, like he did here in post 74. -
Geo Guy at 09:32 AM on 12 July 2010Hotties vs Frosties?
My cudos to you for an entertaining article. I thoroughly enjoyed reading it and tend to side with much of what you said. I do take exception to the statement that hotties are characterized as latte sipping – heck I enjoy a good latte now and then! Hmmm maybe that makes me a “coolie” instead?? As for the chain saw wielding, overweight, middle aged man who drives an old 4WD – I plead guilty as charged!. I need my chainsaw to clear the dead trees that happen from time to time on our property; I am not a hard body ….well I enjoy a cold beer now and then; and I drive a 1993 Isuzu Trooper because it is the best vehicle I have ever owned (380,000 km and still going strong!) and I need the 4WD when we get heavy snowfalls (30 to 50 cm) otherwise we would suffer from a bad case of cabin fever!! Apart from that description, the balance of your characterization does not apply to me. Now I am a “frostie,” not because I am a denier (a term I believe better fits the extreme element of the “frostie’s side just as alarmist best fits the extreme views of that “other side”). Rather I feel there is a role to play in questioning a side when the evidence supporting that side is not iron clad. Before I elaborate further, allow me to post a philosophy which I believe is embedded within the process of scientific evolution. As scientists we must continually question the “status quo”. If we stop doing so, our understanding of science will cease to evolve. Hence despite what the “science” may tell us, there is a definite role for taking a contrarian position. Science is rarely definitive. The application of science is what changes over time and is the basis upon which we evolve as a species. Perhaps we frosties have taken our position because a) we tend to be well educated and b) our education is supplemented with substantial work in our field? As a geologist who first graduated in the early 1970’s and who has spent a substantial time in the field applying what I learned at university, I have come to appreciate the vast differences that exist between scientific principles and the application of those principles in the field. From that I have learned to question and re-question my own observations and my own interpretation of those observations in order to arrive at the best interpretation possible. From those exercises I make it a point to always look at data from all sides and it is this philosophy that places me on the side questioning the validity of reports such as those published by the IPCC. I am not saying I am right and am not saying the other side is wrong. What I do believe is that the answer lies somewhere in the middle of the two positions. We are not talking about irrefutable proof as I contend we are unable to even get close to such a stance until such time as we know everything there is to know about ALL climate drivers in our system. We still have a long way to go in order to get to such a position. Now I don’t have a problem with anyone establishing a position on a subject based on specific criteria or data. However I encourage people on both sides of the argument to seriously assess the evidence from the other side instead of out right rejecting it as is what happens so often. Instead of accepting a paper that was “peer reviewed” as proof of its factual basis, read the paper with a critical eye to identify weaknesses in the argument being put forward. In many instances the conclusions of a peer reviewed paper are only applicable to the environment upon which the study was based and expanding them to a global environment can’t be supported. For instance, recently there was an article posted in this blog dealing with the disappearance of certain species of lizards in Mexico and other locales in the world. There was also a paper published recently that focused on the disappearance of certain species of snakes in geographic areas similar to those identified in the lizard study.. Two studies, the same observations but two conclusions: one pointed to global warming (the lizard study); the other concluded more information was needed to identify the cause. With regards to your sample of temperatures, I believe you have illustrated what I believe is a fault in many arguments which essentially boils down to “since my model predicts what I see, therefore my interpretation of what I see is correct”. How unscientific can one get with such an argument? Since when is it acceptable to cast out statistical theory in favour of a “gut hunch”? Given that each side of the debate can take that same data and apply scientific principles to arrive at proof supporting their respective positions simply illustrates the paradox that exists within the debate itself. As for using models to prove any theory, well that is another problem I have with the debate. Too often people are stating that because a model predicts an outcome we observe today, then the observation is proof that the model is accurate and therefore the theory embedded within the model is true. Sorry but such logic does not fall under the auspices of scientific proof. If it does then the octopus in Germany that had a 100% prediction rate in selecting the winner of certain games at the world cup would be classified as a valid model! Whether you have a model in mind or not has nothing to do with the accuracy of your interpretation of data. I would venture to say that since you do have a model in mind and that you allow that model to affect the way in which you interpret the data, your interpretation is then biased at the outset by the model you have in mind. I would like to outline where I believe my position differs with that of the “hotties” but alas my post would be way too long. Now if the moderator of this blog would welcome an article from me where I elaborate those differences, I would welcome the opportunity to do just that! -
johnd at 09:20 AM on 12 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 07:20 AM, Peter, concentrating for a moment on the location of the instrumentation sites in relation to the tree locations. The instrumentation sites seem well dispersed, however quite some distance from most tree locations especially those at the higher elevations where differences could be significant. I want to mention an example of a study that was related to me by a friend who actually peer reviewed some research that has some relevance I feel, at least philosophically. The research was undertaken in my region but this example could be relevant wherever the natural environment is being measured. The study was comparing the productivity of a pasture based enterprise in relation to climate factors, in particular precipitation. The study was duly completed and sent with it's very positive results for peer review. Fortunately one of the peer reviewers was considered one of the most knowledgeable scientists in that particular field of research, certainly he knew far more than the research scientist who conducted the study. However, more importantly, he also had close personal knowledge of the location of the research site and the first thing he picked up on was the location of the site in relation to the official weather station that provided the required data. The weather station was reasonably close, about 15 km, however the reviewer happened to know that that particular weather station was located in a rain shadow, and any precipitation data collected from there was not representative of the wider area, especially the location of the research site. Thus the conclusions reached by the researcher were completely wrong. I doubt than anyone called upon to peer review the paper who did not have the same personal knowledge as my friend would have understood the significance of those 15 km, certainly the researcher himself who conducted the study didn't. I keep this example in mind whenever I am trying to understand what a peer reviewed study has found. I try and see firstly if any climate data used is from the actual location of the study, and thus can be accepted as relevant, or is it from some distant point, or some general data that has been assumed to be relevant. The second point is whether it is likely or not that those unknown persons called upon to conduct a peer review would have an equal or better understanding of the subject, and the location than those conducting the research. This of course remains an unknown, but in some fields one can accept that there would be better qualified persons who are perhaps more knowledgeable than the researchers, however, when new concepts are being presented, I am often left wondering just how many peer reviewers would be capable of grasping the essence of such new concepts, especially if it goes against the established understanding. We can only but wonder, but ultimately time may answer one way or another as it has done so for those renowned scholars in the past who had trouble getting others to see what appeared so clear to them. -
JMurphy at 08:12 AM on 12 July 2010An account of the Watts event in Perth
skepticstudent wrote : ...but I can't seriously believe anything this person writes... Care to be a bit more specific or do you not believe every word written ? How about the start : "The Watts climate tour appeared in Perth on Tuesday evening." What don't you believe about that ? -
Peter Hogarth at 07:20 AM on 12 July 2010Tai Chi Temperature Reconstructions
johnd at 04:43 AM on 12 July, 2010 John, I agree it is a complex subject. However much of what you say appears to be conjecture and not directly referenced to the research I have seen. I suggest that if you look at the recent references supplied, particularly the ones from the last two years, there is much to learn. There has been a lot of focus on DP and some of the correlation work with temperature is highly convincing (I previously mentioned the seasonal growth and year on year growth correlating with local temperature variations) and Buntgen 2008 for example shows temperature monitoring sites on tha map above. I suspect this would be inconsistent with CO2 as main factor. -
Riccardo at 06:08 AM on 12 July 2010Sea level rise is exaggerated
daniel, "What I am saying is that the tide gauge data points fit inside of that if it were extended over sample 1." They are inside the sedimentary data uncertainty and we expect them to stay there for a while given the difference in the slopes. Ok, but they do have a different slope. Does this tell you something? -
skepticstudent at 05:29 AM on 12 July 2010An account of the Watts event in Perth
anything this person writes either. :-) -
skepticstudent at 05:28 AM on 12 July 2010An account of the Watts event in Perth
John I respect you and I've learned some things on your blog, but I can't seriously believe anything this person rights, and I think you've damaged the respectability of your blog by allowing her to submit a guest post. I don't expect this post to stand but it was meant for you anyway. -
Paul D at 05:09 AM on 12 July 2010Is Willis wrong at WUWT? or Sensitivity and Sensibility II
Berényi PéterOr it's not stored at all, just goes to space. After all that's the coldest heat reservoir around (2.7 K).
That's one of those junk throw away statements. As has been pointed out, the only way the energy can escape to space is via radiation in the upper atmosphere. To do that it has to be fed from below, but GHGs inhibit the provision of the energy 'feedstock' that the upper atmosphere needs.
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johnd at 05:05 AM on 12 July 2010Sea level rise is exaggerated
Peter Hogarth at 16:21 PM, Peter, the comment you make about modern tide gauges taking measurements every 6 minutes or so interests me. Given that at some locations the time it takes for the tide to rise can be considerably longer than it takes for it to fall, just a quick look at one site showed over 15 hours rising, 9 hours falling, would taking such regular measurements introduce a bias into the average when comparing against those records where the average is that of the high and low tide measurements? -
johnd at 04:43 AM on 12 July 2010Tai Chi Temperature Reconstructions
Peter Hogarth at 02:38 AM, whilst temperature is one of the many factors that influences plant growth, and not the dominant one, it's increasingly seems to me that the selection of sites, or groups of trees, is done by finding trees that by COINCIDENCE rather than by science, seemingly track temperature sufficiently well enough for them to be considered useful indicators. I say by coincidence, because if all the other factors that are perhaps even more important in influencing tree growth were sufficiently well understood to be quantified, then all trees should be able to be used as proxy indicators. But more than that, if those factors were able to be quantified, the divergence problem would not be, well, a problem. The problem is not that the growth of trees that had been previously selected as temperature indicators began to diverge, the problem is that the reasons are not understood, and this is happening at a time when the resources and knowledge is available that should be able to identify such reasons. If those reasons are not understood well enough to be able to account for present day situations, then how can anyone be confident enough to claim that those same, still unknown factors, have not been present and an influence, either positive or negative, at other previous times. I would hope that the selection of "good" sites involved more than someone with a wooden ruler in one hand and a temperature chart in the other, but that is what it seems to come down to. The one thing that is always in the back of my mind whenever tree growth ring data is used is that what has been done to ensure that the tree growth is not tracking CO2 levels rather than temperature. With the Buntgen 2008 study, about half of the available sites were selected because of their supposed historic correlation. But those sites used in other studies where the divergence problem is now evident also were supposed to have a historic correlation, so obviously some things change over time. But that doesn't mean that they are only changing now, and haven't done so in the past. So what is there to say that perhaps the basic assumptions used to model tree growth against temperature are wrong, and that instead, the other half of the trees that were rejected are better indicators once everything has been allowed for. If we were to work backwards and select trees that today show good growth correlation with temperature, then those trees that are now showing divergence would be rejected, or else any modelling done that correlated their present day growth with temperatures would when applied to historic growth rings, present a different result. The other thought that is also always in the back of my mind is how well are the actual site conditions documented over time. Temperatures can vary widely even between close localities, so correlation should be to and with site temperatures, not regional or global. Precipitation patterns can vary widely over just a few kilometres. Given that some of the locations where the samples have been taken seem to be remote, perhaps even these most basic of all factors have not been accurately accounted for. -
Peter Hogarth at 04:30 AM on 12 July 2010Sea level rise is exaggerated
In order to also start some fresh productive discussion, hot off the press is the following from Llovel 2010This is a new measured result from GRACE which goes at least some way to confirm explanations of seasonal variations in mean sea level, and partially answers previous points on this post and also answers some questions on the visualizing sea level post. The further relevance is that land storage contribution to mean sea level trend and budget is slightly negative, giving -0.22 +/-0.05 mm/year, confirming modeling results for this with direct measurements for the first time.
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Albatross at 04:22 AM on 12 July 2010Hotties vs Frosties?
Philippe @87, "You went looking for what was wrong and you found it, although what you found did not exist. That is the definition of bias. Philippe, Peter recently made the same error when raging against the lowering of pH. He assures us that he is searching for the truth, but his approach seems to be inconsistent with that. -
Peter Hogarth at 03:52 AM on 12 July 2010Sea level rise is exaggerated
daniel at 23:20 PM on 11 July, 2010 One thing slightly bugged me about my chart, the slight offset between the tide gauge data and the "centre" of the error envelopes, where we would expect the real trend to probably be. I checked the tide stations closer to the site. One (New London, CT, with a shorter record from 1938) is very local, but the other (from 1856, NY) has the longest record. I charted the NY record for this reason. I've now noticed there is a small vertical offset (not unusual between stations) between the two that (subjectively at least) neatly resolves the visible offset in the chart. -
Peter Hogarth at 02:38 AM on 12 July 2010Tai Chi Temperature Reconstructions
johnd at 10:22 AM on 11 July, 2010 No, I think you have misunderstood the methodology. We do not have controlled experimental conditions. The site selection process involves looking at older tree ring data to see if the "site" is likely to give results which are affected by temperature, rather than other factors (such as drought), by comparing pre 1934 tree rings data with pre 1934 historical climate data. If it is a "good" site, on this basis, then the later tree ring data is examined to assess more recent effects of temperature (other factors notwithstanding). No assumptions are made to pre-select on the basis of correlations in later data. This is important. The authors admit that this cannot account for changes in other factors in the meanwhile, but if the correlation with instrumental temperature continues in later data, then confidence increases. I think you see the logic of this? -
Peter Hogarth at 02:15 AM on 12 July 2010Sea level rise is exaggerated
daniel at 23:20 PM on 11 July, 2010 No, you have not said this until now. What you have argued is that extending the approx 1mm/year long term linear trend from pre-tide gauge data beyond 1856 by including point 1 gives a 1.2mm trend and error bars which can fully accomodate the total tide gauge data record anywhere inside this trends error envelope, therefore you argue this paper should not be used as evidence that the recent 2.8mm/year trend is unusual. Your case for including point 1 in an overall 1.2mm trend is invalid. Clearly, the density of tide gauge data makes any influence of point 1 marginal on the measured 2.8mm/yr trend since 1856, clearly, the recent measured trend is diverging away from the long term paleo trend. That point 1 error bars overlap the tide data possibly validates point 1, but the fact that the tide gauge data overlaps point 1 does not validate extending the pre-1856 trend. The post 1856 trend is already determined as measured fact by the tide gauge data. Point 1, statistically speaking, is on this trend. The question you are asking really, is: Can the 150 year tide gauge data trend be accomodated inside the pre 1856 error envelope, and show that the longer term trend could most likely have missed similar episodes of acceleration in the past? This is the question I address in my chart. The chart I have given shows the error envelopes based on the statistics given for each point, up to the start of the tide gauge data, which has much lower standard deviation and represents the measured data. It is not the same as a linear trend. It is likely that the envelope will follow or at least accomodate whatever the true trend was. We can only ascribe a probability to this. It is barely possible to fit the tide gauge data into the 2 sigma envelope in one pre 1800 place, but it is not a "good" statistical fit anywhere over any approx 150 year period except after 1800 (by comparing with at least three paleo points, though this is not a strong test). It is not possible to fit inside the 1 sigma envelope anywhere, and the data series deviates away in opposite directions above and below the envelope, indicating significant systematic trend error. I repeat that your suggestion is possible, but not "likely" from this data. Of course we need a reality check, and the temperature record and other work I referenced strengthens the case presented in the paper, and further weakens your hypothesis. -
Philippe Chantreau at 01:44 AM on 12 July 2010Hotties vs Frosties?
BP, you missed the point. The point was not about the data, it was about your attitude. You started with the assumption that the papers came to conclusions that were wrong. You went looking for what was wrong and you found it, although what you found did not exist. That is the definition of bias. What you found did not exist but you found it anyway because you were so eager to find it that you were going to no matter what. Then you assumed, again without anything to back it up, that the (non-existing) flaws that you found were due to an intent to deceive from the authors. Don't try to deny that, your anger and accusations are patent in many of your posts, and explicit in the acidification one. But you are yet to present ANY kind of evidence of an intent to deceive or even that a paper is wrong. You raise some valid points, but their significance is far below what you suggest (especially the fraud suggestions) and, frankly, you should drop the attitude. It is quite obvious that you need to watch your own bias way more than that which you see in others. -
DarkSkywise at 23:54 PM on 11 July 2010How Jo Nova doesn't get past climate change
Baa Humbug at 20:04 PM on 11 July, 2010: "Human nature JM. When one starts reading the thread and comes across a "hidden" comment, curiosity kicks in," In the beginning: definitely. After a while: no. I've been a mod/admin on several large forums where no post rating systems were allowed, because too many people go around "plussing and minusing" not because they think posts are good or bad, but because they want their own views in sight and others' views hidden. And most of it is being done by one side only, just like with online polls where 60% says ther earth is cooling, it's a natural cycle and AGW is a conspiracy to raise taxes. The result is not only that only one side of the argument is really shown, but it also keeps many people from the other side from posting. Some people just don't like posting anything anymore (especially when they work long and hard on their posts), if the posts will be hidden anyway. Anymoo, my experience with most forums with post rating systems is that they turn political in no time - and it's nearly always the same political side. "All sceintsist are fruads!!!!11~" +283 -12 "Research has shown that (insert lots of text here) which shows a clear trend towards warming." +7 -453
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