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Comments 126201 to 126250:

  1. What do the hacked CRU emails tell us?
    Comment to response in comment #30: "The whole approach of Skeptical Science is to point out that global warming skepticism misleads by focusing on narrow pieces of the puzzle while neglecting the broader picture - the job of Skeptical Science is to communicate the broader picture." I am a bit concerned about your polarization in "narrow" respectively "broad" pictures. I think you are hijacking the meaning of these words which may not be agreed on by everyone. I don't think such attitude will do no more good than deepen the cliff between you and others peoples that may not agree with you to the single letter and point. Modern science is about reductionism and with such tool exclude things as wrong and leave the rest as "possible". When deferring skeptical criticism to be "narrow" and "cherry picking" you are also denying the scientists themselves the very same tool they are supposed to use to strengthen the rest of the scientific communities confidence in a theory as "possible". Implicit, the statement carry the meaning that any scientist that does cherry picking is not doing proper science. This is a very strange position to hold because our confidence in a scientific theory ultimately relies on all the "cherry picking" criticisms a theory is exposed to and is able to withstand.
    Response: I appreciate your comments. Perhaps a more precise description would be that a common pattern in global warming skeptic arguments is to focus on narrow pieces of evidence while ignoring other evidence that contradicts their argument.
  2. The hockey stick divergence problem
    Step outside of dendrochronology and there is no evidence that Northern high latitude plants are struggling. Satellite data suggests that over the past couple of decades the planet has greened including the higher northern latitudes. Look at the references on this page. Read the first line on Nemani et al., 2003. Their figure4 also shows general improved plant growth in N. latitudes. Zhou et al., 2003 suggest improved growing conditions in N. latitude forest is primarily due to increased temperature and go further to say "Changes in stratospheric aerosol optical depth and precipitation have a smaller effect" The strange thing is these papers suggest the trees should be experiencing enhanced growth over recent decades not struggling. Maybe there is a flaw in the interpretation of tree ring data?
  3. What do the hacked CRU emails tell us?
    When working with a dataset it will always happen that data is contaminated in someway or the other. Many times data can be filtered before use, but when a dataset is large it is prone to happen that bad or even faulty data slips into an experiment. Researchers are aware of this and when a result - or a data point - turns up significant, part of the protocol is to do a double check. This is part of the scientific methodology: if something is a relevant factor, an experiment must be conducted to rule it out. What is of scientific methodology concern in the CRU report is not the fact that there exists bad data or the operator has a lot problem to get it working, but the fact that there seams to be a loss of traceability in the experiment and thus it is not possible to do the required double check. This should make us concerned. CRU has received critics for not releasing its data set – which is common practice in science after publication. Other scientist want and will do a double check because in science "my word" for something is not good enough. It's been stated that the dataset has been unavailable due to that it is not ready for release, and this is a valid point to make because if data is released it should be provided in such format that it is possible to replicate the experiment with traceability in the data set – for reason already mentioned. The conclusion I make from the report is that the data set is not in such format right now, and this should make us very concerned.
  4. Why is Greenland's ice loss accelerating?
    ubrew12, it is well know that in the arctic summer air temperature cannot be much higher than the melting point of ice; most of the heat goes to latent heat of melting thus limiting the increase in temperature. On the contrary, temperature fluctuations in winter are much larger because ice insulates the atmsophere from the warmer ocean. This is to say that atmosphere and ice are indeed strongly coupled. Ice and ocean couplig, instead, appears to be particularly relevant when the latter melts the floating ice shelves along the grounding line, speeding up the ice stream feeding the ice shelf.
  5. How do we know CO2 is causing warming?
    guinganbresil, OLR is indeed increasing which means postive energy imbalance; this is one of the (many) evidences of the warming planet. A good collection of papers on OLR can be found here. For the energy balance i'd suggest this Trenberth et al. in BAMS.
  6. Why is Greenland's ice loss accelerating?
    What if the ice-atmosphere system is more highly coupled than the ice-ocean system? Suppose we could assume the ocean was off doing its own thing, and that melting ice was mostly absorbing heat coming from the atmosphere? Perhaps then the ice melt could explain the (admittedly small) slowdown in air warming experienced in the last decade.
  7. Was there a Medieval Warm Period?
    Nevermind, just read: dhogaza at 05:51 AM on 29 November, 2009
  8. Was there a Medieval Warm Period?
    Is if possible that the divergence problem of tree ring anomalous proxies since 1960 is due to global dimming? I believe the earth DID dim during the period 1960-1975 and this shows up in the temperature record as falling temperatures, masking the global warming effect. Tree growth would have been affected by dimming to a degree much greater than just the effect of falling temperatures. Reduced photosynthesis would have led to narrow rings which might have been put down to temperature. Just a thought.
    Response: Yes, it certainly is possible global dimming is one of the causes of the divergence problem. A few studies explore this option. However, the issue is complex - there doesn't seem to be one smoking gun to explain the decline in tree ring growth. More onthe tree-ring divergence problem...
  9. Was there a Medieval Warm Period?
    nofreewind (#46), In your attempt to criticize Dr. Mann with some political commentary, you (or Tierney in this case) selectively quote him from a 2004 blog comment. Yet, left out is the rest of the paragraph: "...Most proxy reconstructions end somewhere around 1980, for the reasons discussed above. Often, as in the comparisons we show on this site, the instrumental record (which extends to present) is shown along with the reconstructions, and clearly distinguished from them (e.g. highlighted in red as here). Most studies seek to "validate" a reconstruction by showing that it independently reproduces instrumental estimates (e.g. early temperature data available during the 18th and 19th century) that were not used to 'calibrate' the proxy data. When this is done, it is indeed possible to quantitatively compare the instrumental record of the past few decades with earlier estimates from the proxy reconstruction, within the context of the estimated uncertainties in the reconstructed values (again see the comparisons here, with the instrumental record clearly distinguished in red, the proxy reconstructions indicated by e.g. blue or green, and the uncertainties indicated by shading)" This is the sort of thing being done as political goons eagerly parse through personal emails looking for dirt or the appearance of dirt. It certainly says more about Tierney and others doing the spin than it does about Dr. Mann. To borrow a line from you, "your comments might be convincing to the guy down the street but they aren't going to work with me".
  10. How do we know CO2 is causing warming?
    I also found: http://www.isprs.org/publications/related/ISRSE/html/papers/332.pdf Which also shows an upward trend in overall OLR.
  11. How do we know CO2 is causing warming?
    Riccardo, I wholeheartedly agree - My concern is that the decreases detected due to trace gases (CO2, CH4...) by Harries and others may or may not result in an overall decrease in OLR. A cursory look at the change in spectrum would imply an overall increase. Do you have a good reference for the overall OLR trend? I found: http://www.atmos-chem-phys-discuss.net/4/2727/2004/acpd-4-2727-2004-print.pdf Which indicates an upward trend for OLR.
  12. What do the hacked CRU emails tell us?
    Scientists are not naturally more honest than the rest of us. They don't have some natural immunity from falling in love with their own ideas, getting defensive in the face of criticism, or believing the idea that corresponds best to their own material well-being. No. What keeps scientist honest is skeptics looking over their shoulder, demanding their data, reproducing their results and critiquing their methods. What is damning about the CRU emails is that they show evidence of collusion designed to prevent anyone from checking their results by refusing to release data, and working to keep dissenting voices out of the journals so they could be dismissed as unpublished. People have noticed that Jones et. al. did not answer FOIA requests. It is a scandal that one scientist should have to submit a FOIA request to get data from another scientist, esp. a publicly funded scientist. And now CRU tells us they threw away the raw temperature data, so nobody can reproduce their results? People who behave like they have something to hide, usually do have something to hide. If Phil Jones et. al. were expert witnesses in a trial, the judge would have thrown their testimony out of court based on what the emails reveal.
  13. Was there a Medieval Warm Period?
    Dhogaza, you said in regards to accessing and replicating the data. "Oh, gosh, such an insurmountable obstacle, you might have to partition a disk and recreate Mann's directory structure on it, the horror! The unscientificness of it! As a software engineer with nearly 40 years experience in my field, this complaint makes me laugh. It might take a day or so to replicate the environment or to change the directory and file structure embedded in the code." You might want to read the programmers comments embedded in the code(not sure what data he refers to), seems like some pretty precise work that they do to determine the earths temperature from thousands of data points, etc etc etc. all very very precise. I Saw Mommy Kissing Santa Claus.... http://www.torontosun.com/comment/columnists/lorrie_goldstein/2009/11/29/11967916-sun.html As you read the programmer's comments below, remember, this is only a fraction of what he says. DHogaza, your comments might be convincing to the guy down the street but they aren't going to work with me! - "This whole project is SUCH A MESS ..." (266) - "But what are all those monthly files? DON'T KNOW, UNDOCUMENTED. Wherever I look, there are data files, no info about what they are other than their names. And that's useless ..." (Page 17) - "It's botch after botch after botch." (18) - "The biggest immediate problem was the loss of an hour's edits to the program, when the network died ... no explanation from anyone, I hope it's not a return to last year's troubles ... This surely is the worst project I've ever attempted. Eeeek." (31) - "Oh, GOD, if I could start this project again and actually argue the case for junking the inherited program suite." (37) - "... this should all have been rewritten from scratch a year ago!" (45) - "Am I the first person to attempt to get the CRU databases in working order?!!" (47) - "As far as I can see, this renders the (weather) station counts totally meaningless." (57) - "COBAR AIRPORT AWS (data from an Australian weather station) cannot start in 1962, it didn't open until 1993!" (71) - "What the hell is supposed to happen here? Oh yeah -- there is no 'supposed,' I can make it up. So I have : - )" (98) - "You can't imagine what this has cost me -- to actually allow the operator to assign false WMO (World Meteorological Organization) codes!! But what else is there in such situations? Especially when dealing with a 'Master' database of dubious provenance ..." (98) - "So with a somewhat cynical shrug, I added the nuclear option -- to match every WMO possible, and turn the rest into new stations ... In other words what CRU usually do. It will allow bad databases to pass unnoticed, and good databases to become bad ..." (98-9) - "OH F--- THIS. It's Sunday evening, I've worked all weekend, and just when I thought it was done, I'm hitting yet another problem that's based on the hopeless state of our databases." (241).
  14. Was there a Medieval Warm Period?
    Seriously, I respect this blog and the blog owner trying to enforce a "code of conduct", but what term could I use but calling Mann a LIAR? in his response to the commenter who asking him about grafting? Please tell me where I am talking nonsense? I have a funny feeling that Mann would come up with a very confident retort as he did in that 2004 RC post. We have to look at credibility, it is vital to science, in fact it is science.
  15. Was there a Medieval Warm Period?
    This is extremely interesting. http://icecap.us/index.php/go/political-climate Let's look at the "credibility" of the Mann of who is at the heart of this data... _______________________________ In fact, one skeptic raised this very issue about tree-ring data in a comment posted in 2004 on RealClimate, the blog operated by climate scientists. The comment, which questioned the propriety of “grafting the thermometer record onto a proxy temperature record,” immediately drew a sharp retort on the blog from Michael Mann, an expert at Penn State University: Mann: “No researchers in this field have ever, to our knowledge, ‘grafted the thermometer record onto’ any reconstruction. It is somewhat disappointing to find this specious claim (which we usually find originating from industry-funded climate disinformation Web sites) appearing in this forum.” Dr. Mann now tells me that he was unaware, when he wrote the response, THAT SUCH GRAFTING HAD BEEN DONE IN THE EARLIER PRIOR COVER CHART, and I take him at his word. But I don’t see why the question was dismissed so readily, with the implication that only a tool of the fossil-fuel industry would raise it. Here it is here on RealClimate: http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/#comment-380 Is Mann referring to the 2001 IPCC? Or whatever cover, you mean he didn't know about it????? This was the fault of the fossil-fuel industry, their influence? Sadly, people who don't know how to type to keep a bookmark folder seem to know very little about any of this!
  16. The physical realities of global warming
    Okay, HR, don't pretend -- but they're only numbers. Pick some other numbers if you like. The point is that the numbers are multiplicative. As to the misanthropy and pessimism of the green movement -- note that I'm the greenie in the above conversation and RSVP is the skeptic. The greenie is the one who's optimistic about our chances of meeting the challenges of the future, and the greenie is the one who doesn't support focusing on population reduction. In fact, the whole point of my comment was to correct the skeptic assertion that striving for sustainability involves reducing quality (and quantity) of human life. Who is the fear monger here?
  17. What do the hacked CRU emails tell us?
    Riccardo, "It would be really poor science if they throw away thousands of data sets just because a few got weird. Indeed, they are studying the divergence problem, which is related more to tree physiology than to climate." I am still not convienced, because it appears to me that the only "cross" checking that resulted in throughing out "wierd" data was only inexistance in the most recent times. Who's to say that if you had temperature readings in the past that you wouldn't find other divergances?
    Response: I was reading through the peer reviewed literature last night, investigating that very question. What they found was the divergence problem has only occured in the last few decades and there is no evidence of similar divergences in the past. They determined this firstly by comparing tree ring records with the instrumental record going back to the early 1800s.

    To look at earlier periods, they found that the divergence problem was mostly found in high latitude northern sites - sites in more southern locations showed much less or no divergence. So comparing divergent northern tree-ring series with southern tree-ring series found that the only period where the two series diverged was in the last few decades.

    Anyhoo, I was reading through this because I'm currently doing a thorough write-up on the divergence problem. Hopefully I'll find the time to complete it later today.
  18. The physical realities of global warming
    I'm not sure I even want to pretend you could reduce population by 35%. No doubt if we ever got a green government it would be a possible 'policy option'. The basic misanthropy of the green movement shouldn't be ignored. I'd fear a government that had an ingrained belief that humanity was a disease on this planet. The Malthusian ideas that we will reach limits have had a long and varied history and you would have lost money if you bet on any of them. The fact that they are appealing today says more about the pessimism in political and social life than it does about any real natural limits. India in the 21st century will not follow the same development path that the US followed in the 20th. We need policies of boundless development to encourage the best future for all. Not fear that these countries we drag us all down in their pursuit of what we have.
  19. What do the hacked CRU emails tell us?
    "In a statement on its website, the CRU said: “We do not hold the original raw data but only the value-added (quality controlled and homogenised) data.” " The fact that they no longer have the "original" data is a big problem. How can anyone independently validate their findings (either in prof or disporf) without the data. Why would any of you believe something/claims that can't be independently verified?
  20. Was there a Medieval Warm Period?
    Mann 2009 is an interesting paper since it shows characteristic MCA patterns particularly warm north atlantic and cold equatorial pacific,another earlier paper, Trouet 2009 linked the persistent NAO+ pattern to cold pacific ocean. I've plotted a map from NOAA dataset with a similar colormap except that i've added two color at the extreme due to some pixel above 1.4°C anomaly in the last decade: http://ultraxs.com/image-8871_4B140B80.jpg
    Response: Thanks for the very relevant link to Trouet 2009 and the NOAA colourmap which is particularly useful because it uses the same colour scale as Mann 2009. I've added the graphic below:

  21. CO2 lags temperature
    toadhall, would you say that a lighter is useless to make a gas tank explode? More seriously, at equilibrium CO2 alone accounts for about a third of the whole effect, the other 2/3 are feedback. The feedbacks are intrinsic in the climate system, not just related to CO2. And indeed the orbital forcing due to the Milankovitch cycles alone cannot explain the ice ages cycles. You are also confusing CO2 as a feedback and as a forcing. What we are seeing now is the increase of CO2 concentration due to an external factor, human emissions. So, CO2 was a feedback in the past but now is acting as a forcing.
  22. How do we know CO2 is causing warming?
    guinganbresil, you can not draw conclusions on the overall energy budget looking just at a small wavelegth range. Ice crystals and aerosol in general, for example, influece the energy budget also in the visible. On the contrary, absorption by CO2 and CH4 is at discrete frequencies and can be assessed by looking at a single frequency band.
  23. CO2 lags temperature
    Correct me if I'm wrong, but CO2 is a pretty useless greenhouse gas. Feedback mechanisms and climate disaster modelling is predicated on a small bit of CO2 induced heating leads to increased atmos water vapour+ methane (a bad greenhouse gases) which leads to a large heating. i.e. CO2 starts it off, but watervapour/methane are the true baddies and contributors to the warming. If there is a 800 year lag between temp rising and CO2, then it suggests that a water vapour/methane feedback loop has already occurred anyway and, when CO2 turns up, it may add to the problem but it is effectively a side issue, driven by temperature and not the other way round. It seems to me that this is the mother of all correlation versus causation mistakes. Would like to hear a layman alternative?
    Response: Allow me to correct you. We have directly observed the enhanced greenhouse effect from rising CO2, both by satellites measuring infrared radiation escaping out to space and by surface observations of the infrared radiation returning back to Earth. They find that more heat is being trapped at the wavelengths that CO2 absorbs energy. This is empirical confirmation of the human signature in the greenhouse effect.
  24. How do we know CO2 is causing warming?
    Riccardo - Thanks for the prompt response! As I understood Harries, the issue of incomplete removal of the ice crystal effects was due to the large difference in FOV of the IMG (8x8Km) and IRIS (95x95Km) detectors. However, I see in Griggs (figure 2 B & C, watch out for incorrect axis labels) that the AIRS detector has a field of view much closer to IMG and it still shows this effect. The increase of the ice crystals (or whatever it is) appears to track with time (1970, 1997, 2002) vice FOV (IRIS-95, IMG-8, AIRS-13.5). I know this is a subtle point, but if this ice crystal effect is not just a messy data issue it seems it would have a significant impact on the overall OLR trend and radiative balance due to the higher brightness temperature over the 800-1000 cm^-1 range.
  25. Was there a Medieval Warm Period?
    To Steve L Thank you for educating me on the term. Googling it took me to this: http://climateprogress.org/2009/03/12/what-exactly-is-polar-amplification-and-why-does-it-matter/
  26. Was there a Medieval Warm Period?
    Standard cherry-picking broght to the extreme consequences. Just a single (and not understood) line of code demonstrates the frode. The magic of out of context claims. It's useless keep crying about "the code's not clear enough". Why the hell should it be? The only thing that matter is the output of the code. I read claims by software engineers that the code is not well written. Probably; i also write the code myself and the only thing a care of is if it's correct, if it run smooth and efficiently, not if it's nice or easily readable. Forget the code, take the data or collect your own if possible, analyze and compare. This is the standard practice. Everything else is just chattering.
  27. Was there a Medieval Warm Period?
    I see what you're saying. I'll take a closer look at Mann's paper next weekend as well as his sources.
  28. Was there a Medieval Warm Period?
    The data is obviously not there otherwise McI would have taken it and reproduced the experiment. No doubt giving his own slant on the results. In fact if the data was free and easily available I wouldn't be surprised if multiple skilled individuals (from both sides of the debate) attempted the same thing. If I had the skill I'd do it tomorrow. The data isn't there in a useable form. I think there is sufficient evidence within the leaked emails to see that is a fact. After all if it's out there why would Jones be threatening to delete stuff so McI can't get his hands on it. Judith Curry's comments on this, while I'd be critical of some points, have at least been an attempt to shed light on the matter.
  29. Was there a Medieval Warm Period?
    This stuff is fascinating. In the last few days I've been looking at studies that Co2science.org lists that address the MWP. Now, I checked out this website and I understand they are not impartial, so please don't waste time explaining that. The thing is, I looked at several of the actual studies at the source (I have academic access) for different areas of the SH dealing with the MWP and to be honest, from a layman's point of view they look just as plausible as Mann's study. How would you address the seeming difference between Mann's results showing the MWP to be limited geographically and the results from other researchers which show a MWP in the SH?
    Response: Mann's study does show regions in the Southern Hemisphere that showed warmth comparable to the latter 20th Century. Eg - the north of South America, mid-Africa, parts of Australia. I would suggest digging through the studies cited at co2science.org, see which regions they focus on and compare those regions to Mann's study. And please report back on what you find.
  30. Was there a Medieval Warm Period?
    We are going to now start to play fair.
    Accusing researchers of scientific fraud based on UNUSED RESULTS found in a program they've toyed around with, when none of that shows up in the published research which is how results are communicated, isn't "playing fair". It's participating in McCarthyism.
  31. Was there a Medieval Warm Period?
    Neither of us are tree ring experts. But I do know that this stuff is EXTREMELY complicated statistical and mathematical data and corrections have to be made for various reasons. Are you trying to tell me that when you write software, everyone can figure out the steps A & B that may have gotten you to G? Are you telling me that it would be quite easy to find steps C to F.
    I would never claim that software engineering is easy, nor understanding other people's code. I don't mind, that's one reason my hourly rate is so high. No one has ever said that science is easy, either. Why this expectation that "anyone can figure out the steps"? I understand the tree ring stuff in quite a lot of detail because I've invested time into doing a fair amount of reading, but I don't know enough to write my own RCS code to create my own chronologies, and I see no reason to learn. But experts in the field can, without doubt (actually I think McI did, but I have no idea if he's done it correctly).
  32. Was there a Medieval Warm Period?
    nofreewind, Gavin already explained at RealClimate that you (and others) are wrong about that code.
  33. Was there a Medieval Warm Period?
    I'm not a climatologist or a computer scientist. But at least I know how to search the internet a little bit! RSVP @17 -- you made two highly uneducated and unscientific assertions: one about expectations and the other about kool-aid. Here is the oldest reference I can find to show how wrong you are (I'm quoting a Cecelia Bitz post at Real Climate): 'Manabe and Stouffer (1980) first popularized the phrase “polar amplification” to describe the amplified rate of surface warming at the poles compared to the rest of the globe in their climate model’s response to increasing GHG levels. Their early climate model had a simple ocean component that only represented the mixed layer of the water. Their model had roughly symmetric poleward amplification in the two hemispheres, except over the Antarctic continent, where they argued the ice is too thick and cold to melt back (see Fig 1). Both poles warmed more at the surface than the midlatitudes or equatorial regions.' I wonder if you'll see this confirmation of the model expectations and start to think that the experts actually know something (and knew it a long time ago). It seems popular, in some circles, to say: Notice that they say "climate change" now instead of "global warming"? What happens in minds when people are told that the IPCC (guess what CC stands for!) was formed in 1988. And what happens in those minds when they find out regional differences in warming were expected before then? When the expectations are met or exceeded by the observations, do they acknowledge that the science made good/useful predictions or do they run off to claim "Kool-Aid" about something else?
  34. Was there a Medieval Warm Period?
    I apologize for possibly misleading someone who knows even less than me. Because obviously there is plenty of tree ring data on the CRU servers, and much of it is related to Mann. Here is comment regarding Mann data. http://www.americanthinker.com/2009/11/crus_source_code_climategate_r.html scroll halfway down. I think you will find that this tree ring data, proxies etc. is EXTREMELY complicated to reproduce, even for an expert, I am sure even for a like-minded colleague. Dhogaza - since 11/20/09 the game has completely changed. We are going to now start to play fair. Truth is the child of time...... --------------------------------------- Climate Audit, can be found throughout the source code. So much so that perhaps the most ubiquitous programmer's comment (REM) I ran across warns that the particular module "Uses 'corrected' MXD - but shouldn't usually plot past 1960 because these will be artificially adjusted to look closer to the real temperatures." What exactly is meant by "corrected” MXD," you ask? Outstanding question -- and the answer appears amorphous from program to program. Indeed, while some employ one or two of the aforementioned "corrections," others throw everything but the kitchen sink at the raw data prior to output. For instance, in the subfolder "osborn-tree6\mann\oldprog," there’s a program (Calibrate_mxd.pro) that calibrates the MXD data against available local instrumental summer (growing season) temperatures between 1911-1990, then merges that data into a new file. That file is then digested and further modified by another program (Pl_calibmxd1.pro), which creates calibration statistics for the MXD against the stored temperature and "estimates" (infills) figures where such temperature readings were not available. The file created by that program is modified once again by Pl_Decline.pro, which "corrects it" – as described by the author -- by "identifying" and "artificially" removing "the decline." But oddly enough, the series doesn’t begin its "decline adjustment" in 1960 -- the supposed year of the enigmatic "divergence." In fact, all data between 1930 and 1994 are subject to "correction." And such games are by no means unique to the folder attributed to Michael Mann. A Clear and Present Rearranger In two other programs, briffa_Sep98_d.pro and briffa_Sep98_e.pro, the "correction" is bolder by far. The programmer (Keith Briffa?) entitled the "adjustment" routine “Apply a VERY ARTIFICAL correction for decline!!” And he or she wasn't kidding. Now IDL is not a native language of mine, but its syntax is similar enough to others I'm familiar with, so please bear with me while I get a tad techie on you. Here's the "fudge factor" (notice the brash SOB actually called it that in his REM statement): yrloc=[1400,findgen(19)*5.+1904] valadj=[0.,0.,0.,0.,0.,-0.1,-0.25,-0.3,0.,-0.1,0.3,0.8,1.2,1.7,2.5,2.6,2.6,2.6,2.6,2.6]*0.75 ; fudge factor These two lines of code establish a twenty-element array (yrloc) comprising the year 1400 (base year, but not sure why needed here) and nineteen years between 1904 and 1994 in half-decade increments. Then the corresponding "fudge factor" (from the valadj matrix) is applied to each interval. As you can see, not only are temperatures biased to the upside later in the century (though certainly prior to 1960), but a few mid-century intervals are being biased slightly lower. That, coupled with the post-1930 restatement we encountered earlier, would imply that in addition to an embarrassing false decline experienced with their MXD after 1960 (or earlier), CRU's "divergence problem" also includes a minor false incline after 1930.
  35. Was there a Medieval Warm Period?
    >As a software engineer with nearly 40 years experience in my field, this complaint makes me laugh. Neither of us are tree ring experts. But I do know that this stuff is EXTREMELY complicated statistical and mathematical data and corrections have to be made for various reasons. Are you trying to tell me that when you write software, everyone can figure out the steps A & B that may have gotten you to G? Are you telling me that it would be quite easy to find steps C to F. With all due respect to Mann, there are various tricks used to correct data for variables, do you think all of various data tricks and methodology were completely explained in a few data files on a server? Do you think the Congressman ordered the Wegman report and the release of data, after the NAS report, because all of this very complex data, with necessary corrections was widely available? That doesn't make "common sense" to this layperson. Didn't you read any of the emails lately which openly discussed not releasing data? The emails may not matter to the science or the reality of climate, but it certainly sheds light on the entire process of how this work is done.
  36. The physical realities of global warming
    I hate to have to keep repeating this, but it is ridiculously simple to assert that population is the only factor that matters. Environmental degradation = population x units of consumption per capita x degradation per unit of consumption. Pretend that you could reduce population by 35% in 10 years and keep everything else the same. That's actually less effective than keeping population level and reducing each of the other two factors by 20%. What is more plausible? India has a population of about a billion, and this billion people imports very little per capita. The ecological footprint (see wikipedia) of the United States is much greater than that of India. Look here: http://tinyurl.com/yjo54rc (from the wikipedia article). See how flat the line is beyond 4 hectares per capita? That means with current technology and infrastructure, much of the developed world could scale back greatly without giving up hardly anything. Development of better policies and technology and, yes, inclusion of reasonable incentives wrt reproduction will have to get us the rest of the way to a sustainable future. Population isn't the only factor that matters.
  37. Was there a Medieval Warm Period?
    NFW: I don't understand. I know Mann works at Penn State, news article yesterday. I didn't know that his data is kept at CRU or NASA GISS, aren't they keepers of temperatures, no tree-ring data?
    Yes, I thought you were talking about McI's whining about 2% of the data used by CRU not some of the tree ring used in Mann's reconstructions.
    The Hockey Stick was pre-2001, yet here I read in the Wegman Report dated 2006 http://www.climateaudit.org/pdf/others/07142006_Wegman_Report.pdf pages 48-49 "4. In response to the letter from Chairman Barton and Chairman Whitfield, Dr. Mann did release several websites with extensive materials, including data and code.
    "releasing several websites" means "here's the URL to the website ..."
    The material is not organized or documented in such a way that makes it practical for an outsider to replicate the MBH98/99 results. For example, the directory and file structure Dr. Mann used are embedded in the code. It would take extensive restructuring of the code to make it compatible with a local machine.
    Oh, gosh, such an insurmountable obstacle, you might have to partition a disk and recreate Mann's directory structure on it, the horror! The unscientificness of it! As a software engineer with nearly 40 years experience in my field, this complaint makes me laugh. It might take a day or so to replicate the environment or to change the directory and file structure embedded in the code. Big deal. If this counts for quality criticism among denialists (and I know it does), then they're just being pathetic. Note the goalpost move, though: 1. The code is secret, we can't run it! 2. The code is public, but it's got hardwired directories in it! We can't run it! Pffft. Scientists aren't in the job of providing software *products* they're in the job of writing code useful for their own research. A ROTFLMAO moment for this highly-qualified software engineer.
  38. Was there a Medieval Warm Period?
    NFW>McIntyre piece http://www.climateaudit.org/pdf/ohio.pdf is his describing how hard he tried to get the actual raw data and couldn't. dhogaza REPLY >The 2% of the data that CRU is not, legally, able to hand out freely. The other 98%, of course, which is all that NASA GISS uses, has been available on the internet for years now. NFW: I don't understand. I know Mann works at Penn State, news article yesterday. I didn't know that his data is kept at CRU or NASA GISS, aren't they keepers of temperatures, no tree-ring data? The Hockey Stick was pre-2001, yet here I read in the Wegman Report dated 2006 http://www.climateaudit.org/pdf/others/07142006_Wegman_Report.pdf pages 48-49 "4. In response to the letter from Chairman Barton and Chairman Whitfield, Dr. Mann did release several websites with extensive materials, including data and code. The material is not organized or documented in such a way that makes it practical for an outsider to replicate the MBH98/99 results. For example, the directory and file structure Dr. Mann used are embedded in the code. It would take extensive restructuring of the code to make it compatible with a local machine. Moreover, the cryptic nature of some of the MBH98/99 narratives means that outsiders would have to make guesses at the precise nature of the procedures being used." So this was the 3rd investigation of Mann. The 1st was the NAS report, then the Congressional hearing, which spawned The Wegman Report. So Wegman says in response to the Congressman Mann released the data. Why did he have to release it if it was at CRU or NASA? Also, they basically state they can't reproduce it because it is such a complicated thing to do. Well, we will have a fourth official inquiry into this matter, maybe the science is not settled, Penn State administration thinks something is not settled. The NAS found his work "plausible", that is pretty much the entire summation of their findings. I am no grammar expert, but isn't plausible a step below possible? Would you use the word plausible to define something that you have a high level of confidence in?
  39. Was there a Medieval Warm Period?
    There is a beautiful graphic of the MWP here. Looks like your german cousin!!
  40. How do we know CO2 is causing warming?
    guinganbresil, in Harris 2001 there's a discussion on the 800-1000 cm-1 range. A short excerpt: "The observed 1 K or so enhancement of the 800-1,000 cm-1 difference signal would be consistent with this, and could also arise from a change in the mean cirrus microphysical properties. We cannot separate these two effects, but we do conclude that the observed window difference spectra strongly indicate an effect involving residual small ice crystal effects, incompletely cleared from the data."
  41. Was there a Medieval Warm Period?
    nofreewind, your graph also stops in 1950 so you can't make any connection between post 1950 warming and solar activity. This was a distortion used by other well known deniers.
  42. Was there a Medieval Warm Period?
    nofreewind, it's hard to comment on a graph without the figure caption or an explanation. It appears to be a reconstruction of solar activity based on 14C cosmogenic production, not sunspot numbers. Anyway, it's related more to solar physics than to climate; in particular, to the possible link between gravitational influence of the planets and the sun activity.
  43. Was there a Medieval Warm Period?
    nofreewind: Supposedly, sunspots were observed as far back as 28 B.C.
  44. How do we know CO2 is causing warming?
    The figure 1C "Change in spectrum from 1970 to 1997 due to trace gases" from the Harries 2001 paper gives the impression that the measured outgoing long wave spectrum has shown an overall drop over the measured range. The figure 1B from Harries 2001 shows the measured difference between the 1970 IRIS and 1997 IMG spectra and it shows a notable increase in the OLR over the range ~800-1000 cm^-1. This increase is also seen in the spectra shown in Griggs 2004 and Chen 2007. Is the decrease in OLR in ~650-750 cm^-1 band greater than the increase in the band 750-1000 cm^-1? It seems to me that for the radiative imbalance to result in overall cooling that the total OLR integrated over the whole band should be decreasing with increasing CO2.
  45. Was there a Medieval Warm Period?
    I know that the suns influence on climate is in dispute, even the skeptics don't seem to be agree on the sun
    The really great thing about denialist "theories" is that they're so self-contradictory yet many denialists hold them all to be true at once. So you can have Watts screaming "there's no warming, it's just UHI" in the morning, and "it's the sun!" during lunch.
  46. Was there a Medieval Warm Period?
    What I like best about McIntyre piece http://www.climateaudit.org/pdf/ohio.pdf is his describing how hard he tried to get the actual raw data and couldn't.
    The 2% of the data that CRU is not, legally, able to hand out freely. The other 98%, of course, which is all that NASA GISS uses, has been available on the internet for years now. Same with Briffa ... Briffa said, "go ask the Russians, it's their data", McIntyre got it from the Russians in 2004, and continued to scream "Briffa won't give me the data", and later, when called on it, "oh, I didn't know it was the same data ..." Sheesh. McIntyre reminds me of a two year old with a migraine.
  47. Was there a Medieval Warm Period?
    I know that the suns influence on climate is in dispute, even the skeptics don't seem to be agree on the sun. But could someone tell me if the Warmers accept this solar activity graphs as true. Even if the affect on climate is just a coincidence, because I remember reading that Warmers saying that there is not enough energy in the suns "changes" to add energy to our system. http://www.landscheidt.info/images/newc141.jpg I find these Fagan books fascinating for many reasons, I just ordered a few more. The Little Ice Age book is so interesting because Fagan goes to great lengths to give all the historical references about the long periods w/o sunspots in the LIA. And what makes these books even better is he is a AGW believer, so we know when he talks history/archeology he is not attacking nything. But I am curious about that graph, were people really measuring sunspots in the MWP? Apprently the telescope wasn't even invented until the 1600's.
    Response: I've reproduced the JPEG image you linked to. I can't confirm the veracity of the graph as it doesn't cite sources but qualitatively it looks right.



    This graph doesn't come from sunspots - as you say, the reliable sunspot data doesn't go earlier than 1600. But solar activity also has an effect on carbon isotopes so this data would be taken from carbon captured in tree wood.

    Note that this graph ends in the early 20th Century. The rise in solar activity in the early 20th Century coincides with early 20th Century warming. If the graph was extended to present times, you would find that solar activity flattened in the 1950s and has shown no long term trend since then (if anything, a slight cooling trend in recent decades). Since the 1970s, sun and climate have gone in different directions.
  48. It's cosmic rays
    I am sure the global warming denialists are going to climb onto the bandwagon that cosmic rays are found to influence tree ring growth - http://news.bbc.co.uk/earth/hi/earth_news/newsid_8311000/8311373.stm - and then try to tie that to proof that cosmic rays are responsible for climate change. What really amuses me about climate change denialists is the fact that they postulate all of these other reasons for climate change, like cosmic rays, water in the atmosphere, and so on, and then state that there is no climate change, or at least that it is not anthropogenic. What a great cop out so that life can continue as normal. And so it goes........
  49. Was there a Medieval Warm Period?
    Ian, I have time to read this site, and I don't consider this site as "nonsense", in fact this seems like quite a scientific place compared to most of what I read. What I like best about McIntyre piece http://www.climateaudit.org/pdf/ohio.pdf is his describing how hard he tried to get the actual raw data and couldn't. Then he asked for advice to reproduce the data with new samples and was told it was terribly technical to do. After a Starbucks coffee he found the same crooked, erratically growing Bristlecone that were used to take the initial samples. No I don't know much about tree rings, but as layperson I am surprised that the scientists use crooked, erratically growing trees as a proxy for anything whatsoever. But I would appreciate someone pointing me to the nonsense in the paper, I am sure RealClimate has it figured out somewhere. Excuse me, but I don't have formal climate science training and obviously regular common sense fails when analyzing many of these issues. I am willing to learn, but need more than "trust me, I did these complex mathematical calculations/error massaging which you could never understand".
  50. Was there a Medieval Warm Period?
    dhogaza, yes I inadvertently referred to the divergence that Briffa discussed in the illegally released e-mails with THE divergence problem which predated Briffa's paper. However, nofreewind was (I think, it is hard to follow most denier's thinking) discussing the Briffa divergence. nofreewind, I do not have the time to waste reading what will no doubt turn out to be non-scientific nonsense by SM.

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