tag:blogger.com,1999:blog-8216971263350849959.post648182910233227601..comments2023-08-07T16:41:49.660+02:00Comments on Die Klimazwiebel: Ten years of solitudeeduardohttp://www.blogger.com/profile/17725131974182980651noreply@blogger.comBlogger64125tag:blogger.com,1999:blog-8216971263350849959.post-33109416404139331652010-01-13T07:34:39.166+01:002010-01-13T07:34:39.166+01:00Hola Edu
might be I am too much discussing with co...Hola Edu<br />might be I am too much discussing with complete nutters.Sorry. With 'the greenhouse theory' I refer to just the fact that GHGs change the energy balance of the surface of a planet and more/less of these gases will change it more/less. I know that's very trivial. This (very basic) greenhouse theory will not change even if there are decades more of no warming (however even there is a limit. If 300ppm more in the air do not have any observable impact on temperatures then we would have to look on the radiative transfer equations again of course), however the importance of other factors you were mentioning might change. The IPCC gives the highest rate of understanding to the action of GHGs however much lower rates for e.g. to the action of aerosols etc. If there were no warming for another decade we would rather look into these parts of the puzzle than into what I called the "basic greenhouse theory".<br />The models describe a certain part of the earth system. There might be mayor longterm factors contributing to steady state climate sensitivity<br />(see Hansen's paper on Target atmospheric CO2, 2008) which are all not included in modern state of the art climate models. Points is it can be that we (certainly we, both of us, in our lifetime) never really know what is the "real" climate sensitivity and which model is "wrong" and which is "right". But that might be a too pessimistic perspective. A constraint of climate sensitivity into a range of ±0.5C might be allready very satisfying and I dont know how many of the existing models that would actually qualify as wrong.Georghttps://www.blogger.com/profile/07807390701146588135noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-46620896387552305842010-01-13T00:31:15.977+01:002010-01-13T00:31:15.977+01:00This is an article that I found interesting
http:...This is an article that I found interesting<br /><br />http://www.economist.com/sciencetechnology/displaystory.cfm?story_id=15211377eduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-9517126301215410732010-01-13T00:29:52.811+01:002010-01-13T00:29:52.811+01:00@ Hola Georg,
as it often happens, it depends of ...@ Hola Georg,<br /><br />as it often happens, it depends of the meaning of the expression 'the AGW theory'. As I tried to explain, I think the probability of periods of no warming depends on the following factors: the rate of increase of the forcing, the sensitivity, the termal inertia and the amplitude of 'internal variations'- perhaps I am missing still a few more,and I am not considering here volcanic eruptions and similar. All, with perhaps the exception of the thermal inertia, are uncertain, so that the longer this period lasts, the estimation of these factors shifts towards a certain range, for instance towards smaller sensitivity. At some point, some of the models will not be compatible with observations any more because their sensitivity would be too large or their internal variability too small. I dont see it as a matter of proving or disproving a theory, which is not very accurate in its predictions anyway, but of disregarding some of the models.<br /><br />what do you mean by 'the greenhouse theory?'eduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-89371360943519520102010-01-11T21:25:36.476+01:002010-01-11T21:25:36.476+01:00I am MORE conservative than the skeptics. Yet the...I am MORE conservative than the skeptics. Yet they DISGUST me with their unwillingness to write clear papers. I can't even tell what the hell McI is doing or which papers he refers to in his blogorhea...he doesn't even properly reference himself! Heck, I still remember McI talking about "bad apples" in the algorithms and you challenged him that the term was not mathematically defined. He could have totally taken that for action and done something with it. Instead he did nothing. What a joker...TCOnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-43841092758470282462010-01-11T15:33:42.526+01:002010-01-11T15:33:42.526+01:00Thanks!/rafaThanks!/rafaAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-72987197847569097322010-01-11T14:00:47.916+01:002010-01-11T14:00:47.916+01:00@57
I think that a blog is not the optimal way of...@57<br /><br />I think that a blog is not the optimal way of disentangle scientific/technical discrepancies. It leads to an endless exchange of postings that perhaps may be hurriedly written. A paper, by contrast, forces the author to focus on a problem during several weeks, weighing many possibilities of errors and rechecking her/his results . Furthermore, usually reviewers have insightful comments. <br />Just to satisfy your curiosity here is an example of the email exchange with Lubos at that time, about 4 or 5 mails. As I said I am not going to engage again on that matter. As you can see the problem was that we didnt get the same result in a simple calculation of the autocorrelation function of the global annual mean temperature, which has been published in many other papers.<br /><br />Date: Tue, 20 Jan 2009 16:54:30 +0100 (MET)<br />From: eduardo.zorita@gkss.de<br />To: Lubos Motl <br />Cc: eduardo.zorita@gkss.de, stephen.mcintyre@utoronto.ca<br />Subject: Re: White noise added<br />Parts/Attachments:<br /> 1 Shown 66 lines Text<br /> 2 525 KB Image, ""<br />----------------------------------------<br /><br /><br />Dear Lubos,<br /><br />my results are different from yours. The autocorrelation from both HadCRU<br />and GISS look very similar and both different from that derived from your<br />model. May be your are smoothing the data, or just considering only marine<br />temperatures.<br /><br />I may also note that such a long time scale as implied by your model would<br />require a much higher climate sensitivity, according to the Schwartz<br />paper.<br />So, in essence, arguing in favor of long climate time constants is<br />arguing in favor of large climate sensitivities<br /><br />eduardo<br /><br /><br />----------<br />Date: Tue, 20 Jan 2009 18:48:48 +0100 (MET)<br />From: eduardo.zorita@gkss.de<br />To: Lubos Motl <br />Subject: Re: White noise added<br /><br /><br /><br />Dear Lubos,<br /><br />I think there is no point in discussing until we cannot agree on the<br />calculation of the autocorrelation function.<br /><br />I can only say I can almost exactly reproduce the result plotted in the paper by<br />Schwarzt: the autcorrelation function of tha annual global GISS temperature after linearly detrending<br /><br />eduardoeduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-83590337534301347482010-01-11T13:54:52.172+01:002010-01-11T13:54:52.172+01:00@Eduardo
To your question: The greenhouse theory a...@Eduardo<br />To your question: The greenhouse theory as such is not in question even with another 20 years of no warming, simply since the most probable reason of mismatch then is not the IR radiative transport of GHGs but that we would have underestimated other factors. <br />To my opinion the models would need a serious and fundamental check if the warming is going on in the next 5-10 years. I think that is pretty straightforward statistics.<br />I had commented on the "unusual" stagnation of temperatures as well:<br />http://www.scienceblogs.de/primaklima/2009/11/what-the-hell-are-they-talking-about-der-spiegel-zum-ende-der-globalen-erwarmung.php<br /><br />http://www.scienceblogs.de/primaklima/2008/07/die-mar-von-der-beendeten-erwarmung-und-den-modellen-die-etwas-vorhersagen.phpGeorghttps://www.blogger.com/profile/07807390701146588135noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-16610407980170182482010-01-11T08:30:14.293+01:002010-01-11T08:30:14.293+01:00Re.#53
I understand you cannot devote your time ...Re.#53 <br /><br />I understand you cannot devote your time to a time consuming task like responding to doubts arising in weblogs. In fact that this is what I consider like "business as usual". But debate on climate jumped to general public long time ago, as a matter of fact let me emphasize you've got your own weblog. So can we still say this is business as usual?. I think it's natural from everybody a demand for all available channels (as long as they are polite and well informed) since this area of science is not "business as usual" due to a variety of reasons we all know. Reading the mails you interchanged on the subject would be a pleasure. Thanks for your prompt response.<br /><br />best/rafaAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-30293557056592388692010-01-11T04:00:26.116+01:002010-01-11T04:00:26.116+01:00Eduardo:
Motl is a string theorist. Those people...Eduardo:<br /><br />Motl is a string theorist. Those people are like a bunch of evil Mike Mann's. A god-fearing solid state experimentalist should have nothing to do with one of these dabblers who is not even wrong.TCOnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-63286830063928161762010-01-11T00:46:17.311+01:002010-01-11T00:46:17.311+01:00@ 52
Mikel,
You have a point with the aerosols, at...@ 52<br />Mikel,<br />You have a point with the aerosols, at least partially. The IPCC states that the level of understanding is low. If you look at the upper panel of the link above, you will see that the indirect effect of aerosols (= the role of aerosols as cloud condensation nuclei and their effect on cloud lifetime) may be even more important than the direct effect. The indirect effect is much more difficult to quantify and locate, and hampers a narrow estimation of climate sensitivity.<br />Yes, there are uncertainties, some of them large. But this does not justify, at least in my opinion, to say that everything is wrong. <br />To hide the uncertainties is wrong.eduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-75759265859070269232010-01-11T00:44:39.665+01:002010-01-11T00:44:39.665+01:00Mikel 49
IPCC AR4 has the net estimate of anthropo...Mikel 49<br />IPCC AR4 has the net estimate of anthropogenic forcing at 1.6 W/m2 with 0.6 to 2.4 W/m2 90% confidence range.<br /><br />Given the relatively low understanding of forcing effect of aerosols compared with GHGs, particularly on cloud albedo, if the value of 2.4 W/m2 or higher is considered to be trivial, how sould we describe positive values of 0.6 W/m2 or lower?<br /><br />The IPCCC evidence is equally supportive of both scenarios.Leigh Jacksonnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-36928488998192336782010-01-11T00:37:13.085+01:002010-01-11T00:37:13.085+01:00#51
'I am fully convinced by Motl's analys...#51<br />'I am fully convinced by Motl's analysis...'<br />Lucky you. I am fully convinced of nothing on Earth :-)<br /><br />I interchanged some mails with Lubos at that time, who also seems fully convinced of his approach. Well, I am not. This would be a bit OT, but I recall that his model could not replicate the observed autocorrelation function. <br />Anyway, we cannot respond to all blogs. Lubos is a physicist that has published in scientific journals in other areas. He can also publish his findings in a formal climate journal as well. We have never tried to scupper paper from critics, quite the contrary. Then we would respond.eduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-83711503646830185592010-01-10T21:34:47.011+01:002010-01-10T21:34:47.011+01:00@ Eduardo 50
I didnt say that the sensitivity of ...@ Eduardo 50<br /><br /><i>I didnt say that the sensitivity of models is biased high.</i><br /><br />No, you didn’t. I did.<br /><br /><i> See lower panel here http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-9-2.html </i><br /><br />Yes, I know. But we can be rather certain about the figures I am using (Climategate notwithstanding). However, the aerosol figures that bring the net forcing dramatically down are, as you said, a bit ad-hoc. Or as the IPCC says, the level of scientific understanding about them is low.<br /><br />I’ve never managed to get my head around an important issue. Since anthropogenic aerosols only manage to stay 1-2 weeks in the atmosphere, their effect can only be regional, not global. This creates two problems: <br />1) If the mid-century cooling had been caused by these aerosols, the effect would be much stronger in the NH. However, HadCRUT shows a steeper cooling in the SH. <br />2) We should be able to see a regional cooling over the emitting areas and downwind from them that would offset the warming elsewhere. Nothing of the like appears in the instrumental record. China and India don’t show any big signs of cooling.<br /><br />But, in all likelihood, I must be missing something. If someone could point me to a paper explaining the above issues, I’d be most grateful.Mikel Mariñelarenahttp://mikelm.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-71855663394173378402010-01-10T18:09:03.545+01:002010-01-10T18:09:03.545+01:00re.# 30
Hans brings to our attention the paper &qu...re.# 30<br />Hans brings to our attention the paper "How unusual is the recent series of warm years". I read it when it was published. I thought then that the question posed at the beginning of the article was quite clever. I was quite impressed when reading the small probability (0.1%) of the high temperatures happening just by "chance". But this feeling was only until I read a detailed analysis of the paper by Lubos Motl (see http://motls.blogspot.com/2009/01/record-breaking-years-in-autocorrelated.html). I am fully convinced by Motl's analysis. I expected then some response from you guys, since the difference in the calculations between you and Motl is almost two order of magnitude. While 0.1% is negligible a ~ 10% it is not.<br /><br />This is the type of discrepancies that leaves interested people truly amazed. Some people says 1 while some other people says 100, and in the meantime the IPCC says the science is well settled ( sounding like a preposterous message because it's a preposterous message). With this type of actual scientific discrepancies (100 to 1) there is some other people wanting to dictate worldwide politics. Once for all let's agree that is preposterous too. <br /><br />best regards/rafaAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-10641203675802131512010-01-10T15:07:12.245+01:002010-01-10T15:07:12.245+01:00@ 49
Mikel, the increase of 0.7 K (plus an overhe...@ 49 <br />Mikel, the increase of 0.7 K (plus an overhead due to thermal inertia, maybe 0.2 K or so) would have been caused by the total forcing, not only GHG. The total forcing relative to preindustrial time is rather 1.5 W/m2 , but with high uncertainty. See lower panel here http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-9-2.html<br />This is why it is very difficult to estimate climate sensitivity from 20th century observations. If the total forcing is small, sensitivity is high and viceversa. Also consider that estimation of aerosol forcing are being often revised<br />http://www.sciencemag.org/cgi/content/abstract/1174461<br />This latest revision by Myhre would shift the sensitivity to slightly lower values.<br /><br />I didnt say that the sensitivity of models is biased high. how should I know?eduardohttps://www.blogger.com/profile/17725131974182980651noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-75208394698048108502010-01-10T04:01:30.340+01:002010-01-10T04:01:30.340+01:00Leigh 48
What is the evidence that AGW to date is ...Leigh 48<br /><i>What is the evidence that AGW to date is trivial?</i><br /><br />Put shortly, that 2.7 W/m2 GHG forcing has only been followed by a 0.7C warming, not all of it attributable to GHGs.<br /><br /><i>If it is true that AGW has so far been trivial,is it reasonable to suppose that it will remain trivial in the future?</i><br /><br />Yes, especially considering that models seem to be biased high. Perhaps due to the important tropospheric aerosols factor that Eduado himself mentioned in his Nature blog post.Mikel Mariñelarenahttps://www.blogger.com/profile/16104103451964316348noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-30601220319102319662010-01-10T02:57:32.572+01:002010-01-10T02:57:32.572+01:00Mikel 43
What is the evidence that AGW to date is ...Mikel 43<br />What is the evidence that AGW to date is trivial?<br />If it is true that AGW has so far been trivial,is it reasonable to suppose that it will remain trivial in the future?Leigh Jacksonnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-82350306838500011252010-01-10T00:07:35.001+01:002010-01-10T00:07:35.001+01:00#29,30
Hans,
while I think the warming concept g...#29,30<br /><br />Hans,<br /><br />while I think the warming concept generally holds true I simply can't put faith in the model results:<br />http://www-pcmdi.llnl.gov/projects/cmip/overview_ms/control_tseries.pdf<br /><br />The models passing this reality test later will fail in precipitation or cloud cover, sea ice, climate sensitivity ... you name it. That's probably why their results are preferably presented as relative changes and anomalies.<br /><br />So to answer Eduardo's question I'd think we could expect another +1K per century ... and if it turns out to be +0.3K the next decade alone I would not be completely convinced but I would be much more concerned - say 50:50 I possibly got that wrong?<br /><br />As for your paper you mentioned: It says that given the temperature signal of the past was nothing but pure white noise (iid signal) fed into an AR1 time series model it would most probably not have generated a distinct number of temperature extremes observed in a certain period of time according to a popular global temperature reconstruction that came under some investigative pressure lately. Now I should be more/less convinced of what?wflammehttps://www.blogger.com/profile/18260929727390446009noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-67580213545108764432010-01-09T23:48:39.304+01:002010-01-09T23:48:39.304+01:00But Reiner, regional temperature changes with a ze...But Reiner, regional temperature changes with a zero global trend would not be a CO2 problem, would it?<br /><br />As for other human forcings, you are right. But nobody is going to look at it until the CO2 nightmare ends.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-36775322551557517412010-01-09T22:48:31.429+01:002010-01-09T22:48:31.429+01:00While interesting, this debate neglects two import...While interesting, this debate neglects two important aspects which need addressing. First, regional temperature changes as opposed to global changes. Even if we get a global zero trend, there may be important changes on a regional level. Second, other anthropogenic climate forcings than GHGs (e.g. land use patterns, aerosols). Roger Pielke Sr. (with many others) has just published a paper on this.<br /><br />They say: <br />'If communities are to become more resilient<br />to the entire spectrum of possible environmental<br />and social variability and change<br />[Vörösmarty et al., 2000], scientists must<br />properly assess the vulnerabilities and risks<br />associated with the choices made by modern<br />society and anticipate the demands for<br />resources several decades into the future.<br />Moreover, since the climate, as a complex<br />nonlinear system, is subject to abrupt<br />changes and driven by competing positive<br />and negative feedbacks with largely<br />unknown thresholds [Rial et al., 2004], scientists’<br />ability to make skillful multidecadal<br />climate predictions becomes much more<br />complicated, if not impractical.'<br /><br />http://pielkeclimatesci.files.wordpress.com/2009/12/r-354.pdf@ReinerGrundmannhttps://www.blogger.com/profile/12759452975366986236noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-13908911924309099892010-01-09T21:55:02.124+01:002010-01-09T21:55:02.124+01:00Eduardo @ 36
If I understood you correctly, you t...Eduardo @ 36<br /><br /><i>If I understood you correctly, you think AGW theory may be right, just the magnitude of the warming is very uncertain. <br />I would rephrase my question then.<br />How large should the warming in the next decade be for you to think that we should limit GHG emissions immediately?</i><br /><br />I think it may be right, but I also think it may very well be wrong. With negative feedbacks. Even with no feedbacks, or with very small ones, it would be a right theory, but a no problem.<br /><br />How large should the warming be to accept there is a big problem, and not just nature? I don't know, I am not the expert. I will listen to the experts and their arguments, and as many kind of experts as possible. That's what I am doing.<br /><br />You may say 0.3 K in the next decade is evidence enough. I'll listen what others say, and I may be convinced by you, or not.<br /><br />Experts with "tricks", "hide the decline", "settled science", and so on, don't have a big chance to convince me. I don't trust activists. And that's why I really apreciate what you are doing in this blog.<br /><br />Let's leave the economical think apart. It's apples to oranges. The financial crisis was not an hypothesis, nor was it a forecast / projection / prediction many decades ahead. A decision was needed, and one was chosen. Not everybody agreed, but that's the usual way.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-63899588633253681842010-01-09T21:24:51.761+01:002010-01-09T21:24:51.761+01:00Leigh, some level of AGW must be happening because...Leigh, some level of AGW must be happening because of basic physics. This was foreseen in the 19th century. But to this date we can't say based on empirical evidence whether the effect is trivial or worth worrying about (if anything, observations seem to support the former scenario).<br /><br />I do think that one decade of no warming puts the IPCC models in trouble if we simply apply the scientific method. But I was thinkig that Eduardo would help me understand this better if I'm wrong.Mikel Mariñelarenahttp://mikelm.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-26457288052140901972010-01-09T20:19:41.608+01:002010-01-09T20:19:41.608+01:00Eduardo @41
That should have been AGW.Eduardo @41<br />That should have been AGW.Leigh Jacksonnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-19673071961223515532010-01-09T20:15:01.440+01:002010-01-09T20:15:01.440+01:00Eduardo 36
Surely another zero decade would ring t...Eduardo 36<br />Surely another zero decade would ring the death knell for AGM, barring some hitherto unknown factor being identified.Leigh Jacksonnoreply@blogger.comtag:blogger.com,1999:blog-8216971263350849959.post-14463674382482595962010-01-09T19:39:13.578+01:002010-01-09T19:39:13.578+01:00Plazamoyua and Mikel
If you accept AGW is happeni...Plazamoyua and Mikel<br /><br />If you accept AGW is happening but consider that decadal zero anomalies are a serious problem for climate models, then how do you interpret zero anomalies?Leigh Jacksonnoreply@blogger.com