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Riccardo at 17:30 PM on 7 May 2010Kung-fu Climate
This very long serie of comments very clearly elucidates the central point of the post, a meaningless Kung-fu fight to distract from the real issues. And this tactic, while useless for the improvement of our understanding of climate, works quite well. This is the other side of the coin of putting a too powerful weapon (science) in the hands of the untrained, chances are that an acceptable (although questionable, as always) piece of scientific work (Loehle's) gets misused. -
skepticstudent at 16:51 PM on 7 May 2010What causes Arctic amplification?
One thing I fail to see in all 30 previous posts on this subject is the fact that in 2008 the temperatures were the third coldest since thermometers were invented in 1775. I lived in Anchorage, AK in 2008 and not only was the winter one of the coldest ever, but October 2008 was the 3rd coldest October in the same history frame. Fort Yukon had temperatures plummet to -79 degrees F for weeks at a time. The Yukon river was frozen from its outlet in Alaska all the way down through the Yukon territory of Canada. I drove along it for miles and have tons of pictures of it being completely frozen in June. It was frozen the whole summer the year before as well. Also one of the things I see no one talking about is the fact that the fabled Northwest passage was completely open and navigable in spring, summer, and fall of 2007, but by winter of 2008 when a liberal ecologist (not an ad hominem that was his own listing) tried to take a kayak followed by two vessels of camera teams, journalists, and assistants tried to navigate the famed Northwest passage to show the world how the evils of ACGW was destroying our earth, the ice had already gathered in such a large vast amount he was turned back. In fact studies show that there was more ice growth in the Arctic in 2008 than in the last 20 years previous. The four famous polar bears talked about by Mr. Gore in “An Inconvenient Truth”, as dying because of Arctic warming. Were actually autopsied by experts and it was found they didn’t starve to death due to too much warming; they died from exposure to extreme cold during the worst wind storm known.(The Eskimo’s and other native tribes are excellent at recalling history of weather for many generations). The same windstorm pattern that blew from Alaska in the west had similar patterns all the way across to Hudson’s Bay in the east. This windstorm in the west also caused a major phenomenon which few people outside the skeptic realm ever talk about. Because there was such incredible wind for such an extensive period of time there was no snow to insulate the ice and make it take longer to build up like usual and the moisture that fell caused exponential amounts of ice to form. Now for any of you who are close to being a skeptic but are unsure, look into the great Northwest passage looked for, for so long by so many… There are verified reports of Canadian vessels traveling east to west across the Inland Passage at least 4 times in the past 200 years. Those that never found it were not there at the right time. Just like the gentleman in the Kayak in 2008. Could it be that the Earth regulates itself, and has for eons and no matter what man does, it won’t allow him to step outside of its control of itself? -
skepticstudent at 15:21 PM on 7 May 2010A peer-reviewed response to McLean's El Nino paper
I will admit that my level of science expertise is not as august as those that surround me. However at the age of 50 I’ve been around the block a few times and I’m able to put 2 and 2 together and see through a few holes. However I would like to make some comments and ask some questions out of full seriousness not being trite. I believe I did offer some evidence in regards to oceanic cooling. The end all be all of scientific focus on the side of global warming seems to be from James Hansen and the NASA Goddard institute, and Michael Mann’s Hockey stick. However let’s just focus on Oceanic Temperatures for now. Since this thread is talking about whether or not the oceanic temperature frame could be cooling or stable and related to Antarctic Ice melt is at the core of that As I mentioned earlier a joint NASA Remote Sensing Systems paper shows the combined science of satellite imagery and oceanic buoy readings which show a general oceanic temperature decline over the last 10 + years. http://www.remss.com/ If you look at their website it shows In Situ Data collocations for the most recently completed day. It shows a group of buoys placed all over the oceans of the world. Now as to your comment of forcings then, versus forcings now, and the forcings that were around 10million years ago that are not active today. What is your basis in fact in this comment? There is ice core evidence and lake bed sediment evidence that during the last 10 million years there have been numerous periods where the ice in the Antarctic has done the same thing as it is doing now, what forcings were in play then that aren’t now. I have heard that said over and over but yet never proven to my satisfaction. One of the major contentions against the McLean/Carter et al.’s paper is that El Nino has been around since about 1895 even though that’s almost a century earlier than what I have heard for the last two decades but I’ll just go with the flow for this argument, the other part of the contention is that McLean/Carter et al. are trying to deny ongoing activity. Well how can you say on one hand this has been going on for a very long time and then on the other hand say that there is no evidence that the forcings 10milion years ago aren’t continuing today? You are robbing from Peter to pay Paul in your argument. I think one of the major errors that people who believe one thing and one thing only are missing is that there is a multiplicity of things causing fluctuations of temperature. Also this is a regional thing not a global thing. Also there has been a major ignoring of the fact that there is evidence over eons, that when the Arctic ice has a major growth pattern, the Antarctic recedes and vice versa. The Arctic ice pattern has had some major growth patterns since 2008. Now if anyone wants to debate me on the amount of snow and ice and windstorms in the state of Alaska in 2008 and 2009 I lived up there and I will be glad to debate you on “warming” in Alaska. I won’t argue that perhaps the Antarctic ice has melted a little more than expect in the last two years. I won’t argue that most likely the Pacific Decadal Oscillation would most likely not be the single culprit of Antarctic melting. But I would also stand strong and deny that any amount of anthropogenic CO2 output is the sole cause of any amount of warming. I’m trying to stay to the theme of this thread but it is rather difficult, without bringing in corollary evidence. You might be asking yourselves where this guy is getting his information from if he admits that he is not a scientist per say. I am a scientist of sorts. I am a Network Engineer and I have to understand electronics and a million other things and piece things together one step at a time forming theories and hypotheses as to what might keep one part of a communications network from functioning properly with another. If that is not the heart of the scientific method I don’t know what is. I have also studied for years about weather and astronomy. I also happen to have two friends who are a retired meteorologist expert for the US Weather Bureau, and another is a climatologist. As far as whether or not the McLean/Carter et al. paper is fit for peer review, I would say that what they were saying is that you have to look at the facts and see that there are other things besides mankind’s contribution to carbon footprint globally. I believe they proved that. Did they prove that the Pacific Decadal Oscillation was the sole corollary cause of global warming? No but having read the paper I don’t think that was the intention. As in so many areas I believe that when science can’t be refuted you attack the scientist. I believe since their paper is stating that other things are at play in any temperature fluctuation and that is the main bone of contention I believe it is fair to quickly discuss the fact once again, that during the carboniferous period there was 7000 to 14000 ppm of CO2. Who drove cars then? What factories were putting out CO2? Was the temperature any different than it is now? (At different periods of time yes at others no) On the opposite side of the coin, there were times when CO2 was at around 400ppm the equator was nearly frozen solid. So the main quest of their paper was to show that CO2 really isn’t the cause of any warming past, present, or future. I’m not going to get into the other areas as they are not within the confines of this thread and I’m trying to play within the rules of this blog since I’m not the author. Ps... I just got an email from Mr. Bob Carter and I advised him of this blog, I'm sure he will be thrilled beyond description over the excitement and enthusiastic discussion of his hard work. -
quokka at 13:59 PM on 7 May 2010Kung-fu Climate
A bit off topic but definitely newsworthy: 255 members of the US National Academy, including 11 Nobel Laureates, defend the integrity of climate science in a strongly worded statement that includes terms such as "deniers" and "outright lies". It seems the patience of the scientific establishment is reaching it's limits. It's about time. Joe Romm reports -
carrot eater at 13:09 PM on 7 May 2010Kung-fu Climate
For what it's worth (and he can speak for himself), I don't get the impression that Loehle intends for his reconstruction to be seen as being above criticism. The relative low number of proxies, the lack of SH coverage, and the difficulty of using low-res proxies - these are problems. The questions are, did he handle these problems as well as one can? At the very least, 'global' just shouldn't be in the title. Leave out the token 3 SH sites, and call it NH, like Moberg did. Moberg is sort of like the cousin of Loehle's paper. And as it happens, Moberg's results are the most similar to Loehle's. -
Rob Honeycutt at 12:17 PM on 7 May 2010Kung-fu Climate
@poptech... I don't think it's okay to post the full text of private emails between Dr Loehle and myself. That would be a breach of trust. But I can assure you that this was definitely the gist of what he said. As well, as I stated before, Dr Loehle has read my blog post and said to me that it was a "good post." I believe I have treated him fairly in my post and he was extremely generous with me in the process. If you can't accept my paraphrasing of his statements to me then I don't think there's anything more I can offer. If the tables were turned I would accept your statements. But that's just me. -
carrot eater at 12:07 PM on 7 May 2010Kung-fu Climate
Poptech: No. I'll happily read a paper. I read Loehle's corrected paper. I'll read a relevant blog post, if you have one. But I'm not going to go digging through a comment thread to find something that may or may not be there. So if Loehle really did address concerns about spatial representation, how to appropriately handle such low resolution proxies, and the lack of attention to calibration/validation, please point directly there. -
Rob Honeycutt at 11:56 AM on 7 May 2010Kung-fu Climate
@poptech said... "Your assertions of Dr. Loehle's motivation are unsubstantiated." Actually NewYorkJ restated what Dr Loehle's words to me were. I think that might just constitute being substantiated. -
scaddenp at 11:52 AM on 7 May 2010Kung-fu Climate
poptech; What raw data are you talking about?? I assumed it was raw data behind Hadcrut. The reasons is as stated. It is not "their" raw data. Most comes ready processed from GHCN. The rest is from national weather centres. It MAY be publicly available - but not from CRU because they are not the data custodians. I would be pretty upset if my raw data supplied to client was made publically available by them. This is just skeptic talking point and off topic. Or are you talking about some other raw data set which CRU collect and are custodians for? -
carrot eater at 11:40 AM on 7 May 2010Kung-fu Climate
Poptech: This is laziness. That's just a blog post that notes that the correction had been put out. Are you telling me that Loehle addresses the remaining issues somewhere in the 356 comments down below? If so, please extract the timestamps of the relevant comments. It's appropriate to give somebody a paper citation to look up. I think it's inappropriate to ask somebody to go fishing through a long list of blog comments. I can't imagine what he could say to defend the simple average, beyond that it was.. simple. -
NewYorkJ at 11:26 AM on 7 May 2010Kung-fu Climate
"Your assertions of Dr. Loehle's motivation are unsubstantiated." It's substantiated by his own words. Imagine if someone had noted a conversation: "And I got that his motivation for this paper was to point out the "politically motivated" science trying to create a MWP that doesn't exist by Loehle and others." "You could say the same thing about Dr. Mann and his motivations for wanting to not show a MWP warmer than today. " That would be unsubstantiated. -
NewYorkJ at 11:21 AM on 7 May 2010Kung-fu Climate
"Peer-reviewed as in refereed." ...by like-minded skeptics for a journal set up for skeptics by skeptics in order to publish contrarian arguments (and not necessarily good ones). "Your comparison to blogs is just absurd." It's rather apt, actually. Blogs aren't useless, though. Occasionally some useful stuff gets presented there that eventually gets published. Example: http://www.realclimate.org/index.php/archives/2008/10/tropical-tropopshere-iii/ What one should object to is treating E&E on par with the many dozens of reputable scientific journals (it's clearly not), when it has the review standard of a contrarian blog. "On the other hand I am basing mine on complaints I have read from him in the past, which were focused on certain (not all) journals." He's always free to publish among those other reputable journals that he doesn't slander. Does it occur to you at all that perhaps some of his stuff has been rejected because it's not very good and he refuses to take apt advice from reviewers? While you can erroneously claim that Loehle has addressed all problems with his reconstruction, do you really think Loehle 2007, riddled with errors, should have been published as is? -
scaddenp at 11:16 AM on 7 May 2010Kung-fu Climate
Poptech - CRU - HadCrut is almost entire GHCN stations which are published. The remainder is extra national weather stations for which CRU is not the custodian. If you want that data you go to the national provider. This has been discussed ad nausieum in media and climate fora. Back to subject? This one is too boring. -
scaddenp at 11:10 AM on 7 May 2010A peer-reviewed response to McLean's El Nino paper
skepticstudent - it would seem to believe things (like broken hockey stick and ocean cooling that are not true. Perhaps you might like to check on that and comment if you have fresh evidence in the appropriate place (not this thread). Antartica - models predicted antartic would grow period. When it is not, then obviously it becomes focus of attention. But it appears that East antartica may be losing mass as well. See antarctic ice which would be a matter for concern. What happened in past isnt that relevant - no one disputes that natural climate change happens (slowly), but the forcing that act in the past arent acting now (or acting to cool but not). -
NewYorkJ at 11:06 AM on 7 May 2010Kung-fu Climate
Rob: "And I got that his motivation for this 2007/2008 paper was to point out the "politically motivated" science trying to obscure the MWP by Michael Mann and others." It is that reason why one might question Loehle's judgment. Prior to actually doing a thorough analysis, he had already made up his mind about the MWP (a co2science.org reader perhaps). Therefore, it seems unlikely he would attempt to publish a reconstruction that did not have a strong MWP, more pronounced than existing reconstructions. -
NewYorkJ at 10:57 AM on 7 May 2010Kung-fu Climate
"NewYorkJ, so far you have been entirely wrong about all your assertions about E&E. Sonja has explicitly stated what her "political agenda" is, which is not what you implied or continue to." Editors should be not be following a political agenda. I understand what her agenda is. "The Pielke quote is his subjective opinion nothing more." Most climate scientists agree with him. Even those like Pielke Jr. who routinely attack mainstream scientists at least value credibility. E&E is no better than a contrarian blog. "The Wigley quote was to show that he accepts E&E as peer-reviewed. Why would I include his discussion of a paper that has nothing to do with the question of E&E being peer-reviewed or not?" Your omission problem was not of that discussion (which was generally relevant to the discussion of the thread topic), but of neglecting the full context of the quote. "Furthermore, I do not think that a direct response will give the work credibility. It is already 'credible' since it is in the peer reviewed literature (and E&E, by the way, is peer reviewed). A response that says this paper is a load of crap for the following reasons is *not* going to give the original work credibility -- just the opposite." Note the quotes around "credible" and the context of the public nature of the study. It's unclear if Wigley believes it's truly a credible peer-reviewed journal or if E&E is falsely perceived as such. "It is illogical. I have overwhelmingly proven E&E is peer-reviewed." Peer reviewed or "peer reviewed"? Blogs are "peer reviewed". It doesn't mean their process is anything remotely credible. For example, as mentioned earlier, I've seen Watts make the baseline error you appear to have made, in an effort to give the appearance that GISS is biased high. I've also seen several hundred responses to such threads where no one bothers to correct him. Credible peer review? "No one is proclaiming systematic conspiracy anywhere. The complaints made towards being published revolve around a select few journals. " If Dr. Loehle has a problem with a few selected journals, he should state those problems clearly and concisely. More importantly, he should then seek to publish in one of many dozens of others of genuinely credible journals, rather than making sweeping ad hominen attacks against all journals, editors, and reviewers that publish climate science-related studies, and towards distinguished scientists like Dr. Mann. -
scaddenp at 10:56 AM on 7 May 2010Kung-fu Climate
Perhaps we could return the debate to some substance. Is there any evidence from paleoclimate reconstructions that would support the idea that the current warming is more due to a natural cycle than to anthropogenic factors? Especially, is there any evidence that MCA cannot be accounted for by known natural forcings which could be also operating today? I see no sign of this in Loehle or anyone else's work. -
scaddenp at 10:51 AM on 7 May 2010Kung-fu Climate
poptech - Hadcrut methodology is published. The entire dataset is not for well publicized reasons which I am sure you are aware of. Since this is immaterial to the debate, why are continuing to bring it up? -
carrot eater at 10:44 AM on 7 May 2010Kung-fu Climate
Look, E&E is a questionable journal with questionable peer review, but just because a paper appears there doesn't mean it's automatically bad. I greatly applaud Loehle for trying. Many sceptics say many things about paleoclimate, but so far as I know, he's the only one to step up and try publishing a reconstruction for himself. McIntyre hasn't. The co2science guys just take papers that mention some period of relative warmth at some spot on earth at some point in time over a period of 600 years, and call it MWP. But unlike them, Loehle has actually tried to put it together. I think his effort (after corrections) still comes up short in some serious ways, but it's a start, and apparently an honest one. As more proxies come available that meet whatever standards he set, maybe he'll revisit, and combine the proxies in a more defensible way (I'm worried about both spatial and temporal), and consider calibration/validation. -
carrot eater at 10:37 AM on 7 May 2010Kung-fu Climate
Poptech: only some of the most glaring (and easiest to fix) issues mentioned by RC there were addressed in the correction. RC points remaining: Dating - I'm not sure that using centennial-resolution proxies here (like Viau)is at all helpful for this purpose. No matter how they tried to interpolate. That said, I think others have gotten published while using such proxies (Moberg, I think?) Fidelity and calibration of individual proxies: Not assessed by Loehle. He's using the proxies as received, and assuming the original authors took care of worrying about such things. Probably not a deal-breaker for getting published in a normal journal; I don't know. Compositing: This is something of a disaster in Loehle's work, I think. Just taking a simple average of all these disparate things and calling it a global record just isn't justified. No assessment of the spatial distribution at all. This is probably the biggest remaining weakness, beyond the choice of proxies. Validation: Loehle didn't. -
NewYorkJ at 10:33 AM on 7 May 2010Kung-fu Climate
The Soon et al. argument appears to engage in the similar silly logic that co2science.org engages in. Brendan noted this in: http://www.skepticalscience.com/Common-graphical-tricks-and-the-Medieval-Warm-Period.html#12894 "What CO2Science are doing is looking for any warm part in each of localised data, then labelling that as the MWP, regardless of the dates involved." This is why multiproxy studies are necessary. Loehle at least appears to make an attempt to get a genuine hemispheric reconstruction. But as RC also noted in their earlier post: "Update (Jan 22): Loehle has issued a correction that fixes the more obvious dating and data treatment issues, but does not change the inappropriate data selection, or the calibration and validation issues. " -
NewYorkJ at 10:18 AM on 7 May 2010Kung-fu Climate
In other words...Sonja's putting her foot back in her mouth after revealing her political agenda. "Pielke Jr. is not a skeptic, go ask him." Did I say Pielke Jr. was a skeptic? Do you only find a statement worth reading if stated by a skeptic? Note also the Wigley quote (much of which you left out) puts quotes around the word "credible". You might be mistaking the appearance of credibility with the reality. E&E was set up to create the public appearance of credibility. Since you quoted Wigley, from the same link, we can view Wigley's thoughts on another E&E paper, on a similar topic. "So what is their method? I need to read the paper again carefully to check on this, but it seems that they say the MWE [LIA] was warm [cold] if at a particular site there is a 50+ year period that was warm, wet, dry [cold, dry, wet] somewhere in the interval 800-1300 [1300-1900], where warm/cold, wet, dry are defined relative to the 20th century. The problems with this are ..... (1) Natural internally generated variability alone virtually guarantees that these criteria will be met at every site. (2) As Nev Nicholls pointed out, almost any period would be identified as a MWE or LIA by these criteria -- and, as a corollary, their MWE period could equally well have been identified as a LIA (or vice versa) (3) If the identified warm blips in their MWE were are different times for different locations (as they are) then there would be no global-mean signal. (4) The reason for including precip 'data' at all (let alone both wet and dry periods in both the MWE and LIA) is never stated -- and cannot be justified. [I suspect that if they found a wet period in the MWE, for example, they would search for a dry period in the LIA -- allowing both in both the MWE and LIA seems too stupid to be true.] (5) For the uniqueness of the 20th century, item (1) also applies. So, their methods are silly. They seem also to have ignored the fact that what we are searching is a signal in global-mean temperature." Obviously, if Loehle or Soon's work had gone through an objective peer review, it's more likely the fatal errors would have been discovered (some of which Loehle later admitted to), and a better quality argument would have been presented to the public. How could anyone be against that? But as noted in the emails, the purpose of such junk science is political. I disagree with Rob about assuming Loehle's assertions of journal bias are entirely sincere, although assuming good faith is generally a good idea. If there was not an audience for such assertions, they probably wouldn't be made. There are many dozens of journals where good work can be published. Proclaiming systematic conspiracy in every one of them doesn't fly, and reflects poorly on the person making the accusations. Instead, those conducting shoddy work make these arrogant claims as a way to boost their stature to well beyond what is warranted by the quality of their work. It's rather shameful, in my view. -
skepticstudent at 10:06 AM on 7 May 2010A peer-reviewed response to McLean's El Nino paper
While I'm thinking about it. Where do you guys stand on the research published in a NASA supported document from Remote Sensing Systems in 2009 where the joint information from NASA Satelites and their globe wide drifting, or Moored buoy's have shown a steady decrease in oceanic temperatures over the last ten years? My first comment was removed without any response overnight, so I don't expect much cooperation on these two comments either. -
Alexandre at 09:50 AM on 7 May 2010Kung-fu Climate
This RealClimate article ellaborates on the subject of how "high" the bar of E&E's peer review is. -
NewYorkJ at 09:36 AM on 7 May 2010Kung-fu Climate
3700+ journals. No E&E http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=K "I'm following my political agenda -- a bit, anyway. But isn't that the right of the editor?" Boehmer-Christiansen - lead E&E editor Also, take a look at the rest of their editorial board. Being "peer-reviewed" by like-minded contrarians admittedly following a political agenda is no better than self-publishing on a blog of like-minded contrarians. Pielke Jr.: "...had we known then how that outlet would evolve beyond 1999 we certainly wouldn't have published there. The journal is not carried in the ISI and thus its papers rarely cited." http://blogs.nature.com/climatefeedback/2007/05/should_hurricanes_be_part_of_t.html#comment-86797 The stuff that ends up in E&E is usually verifiably of poor quality. -
skepticstudent at 09:30 AM on 7 May 2010Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
I should like to know why my comments of yesterday May 7th 2010, were removed? I did not make any political, off topic or ad hominem attacks unlike numerous comments already posted. My comments were very on track and in answer to the comments of Phillipe and the unknown author. I would like to know why after seeing my comments here yesterday evening, are they now gone? Would the author of the blog care to comment?Response: A comment that attacked Gore, Pachauri, Mann, Obama with underhand references to Greenpeace and Peta ventures well into the ad hominem territory and doesn't really add to the scientific debate. Feel free to repost with all the political and personal attacks removed as there was lots of scientific content in there also. -
scaddenp at 07:24 AM on 7 May 2010Kung-fu Climate
HR - oceans can indeed provide a big sink and ocean dynamics coupled with the external forcings could certainly be part of the MCA. Mann and other's think so. I dont understand what you mean about inferring forcing from temperature? Aerosols and solar - the forcing considered are not inferred from temperature. But to the question of whether ocean dynamics are responsible for 20-21 century warming - note the RATE of warming compared to MCA/LIA variations. This would have to represent a very substantial energy transfer in the system which has somehow eluded detection. This is not the way to bet. -
NewYorkJ at 07:21 AM on 7 May 2010Kung-fu Climate
Looks like Poptech (57) is pulling an Anthony Watts. Need to adjust the base period when making the comparison. http://www.woodfortrees.org/plot/hadcrut3vgl/from:1979/offset:0.09/trend/plot/gistemp/from:1979/trend/plot/uah/from:1979/offset:0.24/trend/plot/rss/from:1979/offset:0.24/trend Pretty good correlation, but UAH is somewhat of an odd one out. Not a surprise, though. Their 1979-1997 trend once erroneously showed cooling. E&E is a poorly-cited journal that can't be considered "peer-reviewed". It's the rough equivalent to self-publishing on a blog if one has a contrarian view, but that's already been covered. -
scaddenp at 07:19 AM on 7 May 2010Kung-fu Climate
poptech - "Harries has been challenged". No successfully though. Now lets see you explanation for the observed upper stratospheric cooling. Either way, your statement that attribution to CO2 is purely based on models is demonstrably wrong as the link to John's article shows. Also, bashing what you dont like about CRU when its results are practically the same as GISS is irrelevant to the argument at hand. Loehle provided CRU data but for the purposes of the argument GISS is identical. Your objection to the argument on the basis that the instrumental extension is suspect in baseless. Records that meet your requirements give the same result. -
chris at 07:18 AM on 7 May 2010Kung-fu Climate
daisym at 06:09 AM on 7 May, 2010 You're a factor of 10 out in your reading of Figure 2 in the top presentation. The temperature rise from the depths of the LIA to the mid 20th century was in the most extreme N. hemisphere reconstrution around 0.6 oC. Since then we've had another 0.6 oC. So the temperature rise is around 1.2 oC (not 12 oC!). Antropogenic enhancement of greenhouse gas concentrations has made a significant contributing to warming even during the period from the LIA to the mid 20th century, although most of this has accrued since the end of the 18th century. So at the end of the 18th century atmospheric [CO2] was around 280 ppm. By 1940 this had reached around 310 ppm. The rise was pretty much all anthropogenic. Within the mid range of climate sensitivities (around 3 oC of global surface warming per doubling of astmospheric [CO2]), this increase of [CO2] is expected to have contributed around 0.44 oC of warming at equilibrium. Since this occurred over a very long period we can have expected to have got perhaps 0.35-0.4 oC of this by 1950. So a large chunk (likely more than half) of the warming from the bottom of the LIA to mid 20th century was anthropogenic. The rest was likely recovery from the anomalously low solar output during the period of the Maunder minimum and high volcanic activity during the period of the LIA... -
Rob Honeycutt at 06:46 AM on 7 May 2010Kung-fu Climate
@daisym #96... I think you have to remember that Loehle 2008 is only one reconstruction out of a dozen or so. His reconstruction is also based on a few data sets, only two of which are southern hemisphere. So, I wouldn't take his chart as the definitive picture of the past 2000 years. If you read his paper this is about what the picture looks like without treering data. Second, I don't think anyone is claiming that the warming since the LIA was in any way anthropogenic. The concerns are over mostly over the warming since the 1950's. That's just the last rise you see on the chart. And remember the data there ends at 1992 so there's a good chance that spike nearly hits the top of my chart for where we are now. Again, it's pieces like the warming in Loehle's chart from the late 1600's to the late 1800's that gives me pause for concern. That would mean that the climate is extremely sensitive to change with natural mechanisms. If that is true then this suggests that we are in the very early phase of what is going to be a very rapid rise in global temperature. Honestly, I'm hoping that Loehle 2008 is overstating temperature swings and Mann is more accurate, not for any political reason but because Mann's chart would suggest that climate is less sensitive and we still have time to deal with this issue. -
Chris G at 06:11 AM on 7 May 2010Kung-fu Climate
Alterna #83 "We have decisions to make for ourselves and future generations, don't we have enough data already to move forward? " IMHO, certainly we do, but you are entering into the social psychology/morals area of the situation. The people who are in positions to make decisions are mostly elected officials. Being good at politics and being good at science are pretty independent; so, there aren't very many elected people in high places who really get the problem. In any case, elected officials don't get re-elected if they do things that upset the majority of voters. The average person has a poor understanding of science and statistics, and a desire not to believe that bad things might happen to them. Risk management is typically not so good either, even if they are told the odds. And, like a commons problem, it's not in any individuals best interest to give up the cheapest apparent energy (Fossil fuel costs are sometimes externalized or hidden). The average person is the majority; so, here we are. I believe the whole point to blog sites like this is to spread the word, or to help others to spread it. -
chris at 06:10 AM on 7 May 2010Kung-fu Climate
A few points about the top article. 1. Loehle's reconstruction is really an attempt at a selective low resolution Northern hemisphere reconstruction. There are nominally three S. hemisphere sites. However one of these is pretty much on the equator and the other two are somewhat dubious as proxy temperature series for the last 2000 years, especially in addressing the relationships between temperatures now and during the MWP: (a) The South Africa speleothem reconstruction of Holmgren et al (1999). These authors have shown that the del-18O (the normal temperature proxy) record in their stalagmite doesn't correlate with temperature. Instead they tested a phenomenological measure (the "greyness" in the stalagmite bands which they consider may relate to temperature) by comparing this ("greyscale") with temperature during a very short near-contemporary period (1981-1995). This proxy hasn't been independently verified against other late 19th-20th century temperature sets, and while it might be a suitable proxy, the evidence to support this is not that strong. (b) The SE Atlantic sediment record of Farmer et al (2005). The dating of this record is not suitable for a comparison of 20th century and Medieval temperatures. This record covers the entire Holocene and back into the last ice age; it's an excellent record for those long periods. However the latest verified (14C) date is 1053 AD with a 400 year uncertainty at 95% uncertainty. Using it in a temperature reconstruction requires making assumptions about the dating that likely have poor validity. Even if one takes the dating at face value, the sediment indicates that the MWP period was cooler than now. 2. This leads to the second problem. As CBDunkerson [21:50 PM on 6 May, 2010] has pointed out, the inclusion of a couple of rather inappropriate S. hemisphere series into a low resolution N. hemisphere reconstruction does not a global paleoreconstruction make! The weighting is horribly skewed. If one really wanted to attempt a global reconstruction with this data (they shouldn't!), they should increase the weighting the S. hemisphere reconstructions (this will have the effect of reducing the apparent global warmth of the Medieval period). 3. It's obvious that if one is interested in assessing Medieval temperatures compared to now (after all that's what Loehle does, as is explict in his abstract), the contemporary temperature record should be included. Rob accordingly does so in his top post. However, there is no very good reason to smooth the direct temperature measurements. The reason that Loehle applied 29 or 30 year smoothing was to remove short term variability ("noise") and to aid fitting disparate data sets onto a common record. However the measured data is already smoothed and doesn't have any of the noise associated with low resolution data sets in the proxy records. Why misrepresent a perfectly good temperature series? The implication of Loehle's approach is that the more that one reduces information content in paleodata, requiring more energetic smoothing to accommodate noisy and disparate data sets, the more one can truncate the high resolution contemporary temperature data. Incidentally, since the Loehle reconstruction is essentially a very low resolution N. hemisphere reconstruction, it would seem appropriate to compare this to the N. hemisphere temperature record. This is currently around 0.4-0.5 oC above the temperatures of Loehle's reconstruction. -
daisym at 06:09 AM on 7 May 2010Kung-fu Climate
An examination of Figure 2: "Loehle 2008 temperature reconstruction with Hadley instrumental record", shows that our current upward temperature "trend" is displayed between the years 1600 to 1990, a period of about 390 years. The temperature anomoly began at about -5.4 and at 1990 was +6.8, a change of +12.2. Clearly, manmade greenhouse gas emissions were a problem long before the Industrial Revolution. Why do we attribute recent warming to manmade greenhouse gases if the warming trend began nearly 400 years ago? Is there any correlation between the graphed temperature anomolies and CO2 increases during this period? -
s1ck at 05:09 AM on 7 May 2010Kung-fu Climate
It may be of interest that Huston McCulloch (the co-author of the corrigendum to the original Loehle article) has provided supplementary informations, containing weighted least squares estimates. In the resulting reconstruction (p. 12), the maximum of the medieval warm period is only slightly warmer (perhaps 0.1°C or so) than the end of the curve (1935). I guess it would not stand out within all those spaghetti curves in Figure 3. Supplementary Information -
carrot eater at 05:01 AM on 7 May 2010Kung-fu Climate
robhon: I don't see why you couldn't use GISS, too, just for overlay. You just won't have data at 1850-1880. Loehle didn't, but if you were going to calibrate/validate the entire reconstruction, then you'd probably use CRU. It gives you more of a time span, to divide into calibration and validation intervals. -
pdjakow at 04:54 AM on 7 May 2010Kung-fu Climate
@Ned Spencer play with his numbers more than GISS guys. Maybe this is real difference. -
KR at 04:41 AM on 7 May 2010Kung-fu Climate
Chris G, in #75, #80, and #82 - you're absolutely right, local events such as forest density, drought/flood, which side of a hill the tree is on WRT the sun, etc., are all complicating factors in identifying long term growth rates. Personally I am willing to trust tree ring data for short term (couple of year) periods in terms of relative growth, but long term growth studies require _careful_ consideration of these other factors. Tree ring data is useful; IMO it's one datum that can be weighed into the paleo temperature data. But it's by no means overwhelming due to the potential biases, and if it disagrees with 10 other records I would have to vote for the majority. -
Ned at 04:38 AM on 7 May 2010Kung-fu Climate
pdjakow, it's not clear from Poptech's comment whether "0.3C cooler" referred to an offset of 0.3C or a difference in trends of 0.3C/century. As mentioned in other comments above, all the major global temperature indices show a trend of +1.6C/century except for UAH, whose trend is +1.3C/century -- i.e., 0.3C/century cooler than the rest. -
pdjakow at 04:30 AM on 7 May 2010Kung-fu Climate
GISS/UAH without offset GISS/UAH with offset -
pdjakow at 04:26 AM on 7 May 2010Kung-fu Climate
@poptech "oamoe, your comparison is misleading as UAH trends 0.3C cooler." UAH and CRU/GISS uses different base periods. Did you notice that? UAH anomalies refer to 1979-1998 base period and CRU refer to 1961-1990 base period. GISS refer to 1951-1980 base period. In 1979-1998 base period GISS anomaly is equal to +0.24, so real mean difference between GISS and UAH is equal to 0.06. -
Rob Honeycutt at 04:02 AM on 7 May 2010Kung-fu Climate
Being a general aviation pilot myself I like Mythago's analogy. But I would refine it slightly. What we are facing is called a "box canyon" hazard in aviation. We're flying into a box canyon below the ridge line. As the canyon narrows we eventually lose the capacity to make a 180 and turn out of the canyon. If we choose to climb, well at high elevations our aircraft has a limited climb rate due to thin air. As we travel forward, if the rate the terrain is rising below us is faster than our aircraft's climb rate we... um, have limited and unpleasant options. To mix metaphors a bit, when I look at the hockey blade (never mind the damn stick) I'm more concerned about the box canyon we're flying into because we are distracted with less important issues (i.e., the MWP). -
Kung-fu Climate
Re: Ned @85, Perhaps a new skeptic argument is in order: "Scientists won't release the raw data". If nothing else, it would be great as a compendium of raw data and software sources to expand on what Ned listed. -
Rob Honeycutt at 03:36 AM on 7 May 2010Kung-fu Climate
Just to be clear, I believe Loehle provided me with the Hadley numbers specifically because they matched the 29 year smoothed averages that his data has. Nothing sinister going on with which data is being presented here. I had originally started to use GISS ten year average, which obviously showed a more recent and higher end point. But my intent was not to try to show HOW much warmer now is than the MWP. I'm saying that everyone's paleo climate model ends up with the same hockey stick blade, but this fight seems to be over the shape of each study's handle. I also received a nice email from Dr. Loehle saying that he thought it was a "good post." He also notes that 18 sets is not enough data (which he alludes to at the end of his paper saying future studies need more and better data to refine what he's done) and that the data are hard to get hold of since many people don't archive. I believe the second issue is one that is beginning to be resolved amongst researchers. -
Ned at 02:46 AM on 7 May 2010Kung-fu Climate
CoalGeologist, I think we've reached the point where there's nowhere left for the goalposts to be moved. I've provided a link to CRU's software and data. GISS makes all their software and data available here. A number of people have run or re-implemented CRU's software (e.g., here) and Clear Climate Code has precisely duplicated GISS's software. Various other people have published their own open-source software for doing the same thing (e.g., here and here and here). All of those give the same trend (+1.6 or +1.7C/century). It's also the same trend as RSS provides, based on a completely different set of data and methods. So here's my question for Poptech: You wanted the code; now, what are you doing with it? Lots of other people are using the CRU code or GISS code or their own code to do interesting investigations, and in the process demolishing one "skeptic" claim after another. For years, Anthony Watts has skated along by showing photos of weather stations and just asserting that these prove there's a problem with the global surface temperature record. But he never did any quantitative tests to see whether his assertions were justified. Thanks to JohnV and Menne and Tamino and Zeke Hausfather and all the others, it's now clear that pretty much all of Watts's claims were over-promised and under-delivered. -
Dennis at 02:29 AM on 7 May 2010Kung-fu Climate
Poptech @50: What is your evidence that the models are "subjective opinions of the scientists," and not objective measures based on sound data? -
Alterna at 02:23 AM on 7 May 2010Kung-fu Climate
To get back to the conclusion of the original post (but perhaps a bit off from the details), we have to decide how fast we are going to make changes (if at all). I view it this way - how far from sustainable do I think our current system is now, and how fast do I think attributes that support a long-term quality of life are declining (i.e. various ecosystem services). The past 200 years have seen tremendous losses of habitat, increases in pollution (notably nutrient pollution and those from fossil fuels), and staggering declines in the ranges and populations of countless species. Almost every graph relating to environmental studies is some sort of "hockey stick" demonstrating extremely rapid declines or increases over the last 200 years (human population correlated with most for good reason). There surely are some holes or gaffes in climate science, just like in any science. Do climate change "skeptics" really side with the opinion that the significant, widespread, and rapid changes that we have made to the global carbon cycle over recent years have no significant impact on our climate? An even if they do, don't they agree all of the other direct and well-understood negatives of fossil fuel use demand a rapid change to clean energy? I hope this isn't viewed as too off topic, it is meant in the same spirit as the final paragraphs of the original post. We have decisions to make for ourselves and future generations, don't we have enough data already to move forward? -
Chris G at 02:18 AM on 7 May 2010Kung-fu Climate
There are also culling events in forests. This matters because trees packed in amongst other trees get less sunlight than trees less densely packed. Foresters will tell you that they can see patterns of rapid growth and slow growth for individual trees based on how closely packed the forest is. It's just more noise that has to be averaged out, but let's play a hypothetical. Suppose there was a drought over a region that killed X% of the trees. Following the drought, the survivors would show decades of higher growth from the lessening of competition. What would that look like from 500 years later when all you have left are the trunks of the survivors? How would you tell the difference between that and a temperature rise over the same region and period? Again, a correlation with temps would remain, but it would be hard to filter out that signal. -
tobyjoyce at 02:01 AM on 7 May 2010Kung-fu Climate
In post 5, responding to: http://www.skepticalscience.com/Common-graphical-tricks-and-the-Medieval-Warm-Period.html Brendon fixed the Medieval WArm Period as : "Firstly take notice of what is commonly regarded as the MWP period, a time from AD 950–1250, that's 300 years centered around AD 1100." If that is the case, Loehle is somewhat off in his timing for the MWP. His MWP peaks at 850 then falls of, with a smaller peak about 1250. Most of the other charts seem to get their timing more accurately set. -
Chris G at 01:54 AM on 7 May 2010Kung-fu Climate
Ach, "...these _are_ kind..." The timing of the precip in relation to the growth season is also a complicating factor. So, just musing, if there is a general trend across studies where tree growth has declined while temperatures have risen, that could be an indication of either crossing over to the too-warm side for the tree or a general shift in rainfall patterns. Neither interpretation bodes well, or should lend credence to the idea that the divergence is a reason not to be alarmed at the current (and future) state of affairs.
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