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What do the hacked CRU emails tell us?

Posted on 22 November 2009 by John Cook

Earlier this week, the servers at the University of East Anglia were illegally hacked. Emails dating back to 1996 were stolen and leaked onto the web. Phil Jones, the director of the Climate Research Unit, has confirmed the emails are not forgeries although there is over 60Mb worth of material - they can't guarantee all of it is genuine. What does it all mean? Michelle Malkin labels it the global warming scandal of the century (of course the century is only 9 years old but even 'scandal of the decade' would be no mean feat). James Delingpole at the UK Telegraph claims the emails are the final nail in the coffin of 'Anthropogenic Global Warming'? So just what do these emails tell us?

Some of the emails must be embarrassing for the authors. One email responds in poor taste to the death of a well known skeptic. There's scathing discussion of skeptics such as Steve McIntyre and Roger Pielke, including imaginings of violence. However, the crucial question is whether these emails reveal that climate data has been falsified. The most quoted email is from Phil Jones in 1999 discussing paleo-data used to reconstruct past temperatures (emphasis mine):

"I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) and from 1961 for Keith's to hide the decline."

What do the suggestive "tricks" and "hiding the decline" mean? Is this evidence of a nefarious climate conspiracy? "Mike's Nature trick" refers to the paper Global-scale temperature patterns and climate forcing over the past six centuries (Mann 1998), published in Nature by lead author Michael Mann. The "trick" is the technique of plotting recent instrumental data along with the reconstructed data. This places recent global warming trends in the context of temperature changes over longer time scales.

The "decline" refers to the "divergence problem". This is where tree ring proxies diverge from modern instrumental temperature records after 1960. The divergence problem is discussed as early as 1998, suggesting a change in the sensitivity of tree growth to temperature in recent decades (Briffa 1998). It is also examined more recently in Wilmking 2008 which explores techniques in eliminating the divergence problem. So when you look at Phil Jone's email in the context of the science discussed, it is not the schemings of a climate conspiracy but technical discussions of data handling techniques available in the peer reviewed literature.

In the skeptic blogosphere, there is a disproportionate preoccupation with one small aspect of climate science - proxy record reconstructions of past climate (or even worse, ad hominem attacks on the scientists who perform these proxy reconstructions). This serves to distract from the physical realities currently being observed. Humans are raising CO2 levels. We're observing an enhanced greenhouse effect. The planet is still accumulating heat. What are the consequences of our climate's energy imbalance? Sea levels rise is accelerating. Greenland ice loss is accelerating. Arctic ice loss is accelerating. Globally, glacier ice loss is acceleratingAntarctic ice loss is accelerating.

When you read through the many global warming skeptic arguments, a pattern emerges. Each skeptic argument misleads by focusing on one small piece of the puzzle while ignoring the broader picture. To focus on a few suggestive emails while ignoring the wealth of empirical evidence for manmade global warming is yet another repeat of this tactic.

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Comments 51 to 96 out of 96:

  1. What worries me most is the science discussions suddenly turn into politicized discussions where pro- and contra- arguments fly across the table. There is no need for a contra AGW discussion, the CRU data hack didn't change the discussion at all, because man made global warming is widely accepted despite the fact that real data are added back in.
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  2. To date, there has not been a single credible journal article that shows a natural cause for the modern day warming while also showing how record high greenhouse gas concentrations are not significant. NOT ONE. Do people really believe that the scientists at CRU are able to squelch every scientist on the planet who tried to publish this landmark anti-AGW paper? Is there no sense of the low probability and the large scale of this conspiracy for this to be true? If one throws out the HadCRU data and all papers by these folks, there is still a mountain of evidence for AGW. Do the rapidly melting ice sheets and glaciers have access to these emails and joined in on the conspiracy? Do the various climate models that show GHGs as the dominant forcing mechanism have access to these emails and joined in on the conspiracy? Do the GISS, UAH, RSS data have access to these emails and joined in on the conspiracy? Certainly Spencer and Christy would not align themselves with AGW and yet their satellite-derived measurements track reasonably with GISS, RSS, and HadCRU. Does the ocean read these emails and magically increase its heat content? Does the cooling stratosphere (even accounting for ozone loss) read the emails and join in on the hoax? Do the plants and animals read these emails and decide to die off and/or change their migratory habits so that they can support the conspiracy? I could go on ad infinitum. For quite a long time, we have known that a doubling of CO2 will warm the climate at least 1C and there is fairly good certainty that the resulting feedbacks will produce at least 2C additional warming with 3C more likely. We are also measuring CO2 increases of 2 ppm and climbing (except last year where there was a slight decrease due to the global recession) and we have levels that have not been seen in the past 15 million years. Are we to conclude that these emails deny all of this evidence? It is obvious that pre-Copenhagen, the tried and true method of “if one does not like the message then attack the messenger or redirect the conversation” practiced by Big Tobacco and now Big Oil and their front groups (Heartland Institute, George C. Marshall Institute, Competitive Enterprise Institute, etc.) is alive and well. Scott A. Mandia – Professor, Meteorologist, Concerned Citizen http://www2.sunysuffolk.edu/mandias/global_warming/
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  3. "Objectively" chosen or not, temperature reconstructions being what they are, it is virtually unavoidable to separate measurements into the ones that reflect a real temperature signal and those that do not. You have to make some assumptions one way or the other. If you already know what the "correct" answer is, it is human nature(at least IMO) to be more likely to reproduce that answer again.
    Have you read anything on how, for instance, tree ring chronologies are chosen for temperature proxy work? It's not based on "confirmation bias" based on recent warming, but rather on site characteristics and ring morphology that reflects known temperature signatures in tree ring tissue based on knowledge of tree physiology. The confirmation bias, I guess, would be the assumption that trees today grow very much like trees did a thousand or two years ago. The weakest assumption - acknowledged in the literature - is that the single most significant limitation on growth is likely to remain the same for long periods of time at a single site. The basis for this assumption, I imagine, is that the "long" timescales they're looking - one or two thousand years, say - are just a blink of an eye geologically. But that's not "confirmation bias" as you're speaking of it. Really, go read, don't speculate. I spent a day reading up on the dendro/temperature proxy stuff - reading intelligently (i.e. ignoring McIntyre, jeff Id, and the like in favor of scientific sources of information) - and was able to learn quite a bit. Enough to know you're just speculating.
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  4. John, this is a very serious disagreement over the physics of planetary warming, or lack thereof over the last few years. It has the potential to profoundly impact policy-makers decisions. Can you explain the physics to Trenberth's satisfaction?
    Can you explain why Trenberth disagrees with your assessment regarding policy to my (or anyone's) satisfaction if your reading of the tea leaves (sorry, "random selection" of purloined e-mail) reflects the level of uncertainty being discussed? As Ternberth himself complains, his scientific work is being misrepresented by the denialist camp. A relatively minor problem - existing instrumentation isn't sufficient for researchers to close the earth's energy budget during La Niña (the cooling he's talking about) - is being misrepresented as somehow contradicting the underlying physics or the basic fact that the earth is experiencing a long-term statistically significant warming trend. "We don't precisely understand the physics of how La Niña shuffles energy around" does not translate into "maybe global warming doesn't exist", etc.
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  5. I'm sorry, but it is not true that the inaccuracy of the proxy data within about 0.5C of current temps has nothing to do with the MWP. Many points during the MWP had similar proxy values to the post 1961 values. (http://www.21st-century-citizen.com/Hockey_stick_chart_ipcc1.jpg) If the post 1961 proxy values can mean that temperatures are as high(or higher) than current ones, then obviously it is *possible* that MWP temps were also as high (or higher) than currently. Also, it bears mentioning that it does not follow necessarily that a warmer MWP means that feedback is higher, it is also possible that forcing was higher than our current estimates allow for. Cheers, :)
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  6. This isn't science, its arranging data to suit a pre- conceived agenda
    Yeah, the "preconceived agenda" which is ... hmmm ... let me think: The instrumental (thermometer) record is more reliable that tree ring proxies, and when they conflict, the direct measurement is preferable to the indirect proxy. Some agenda. Some conspiracy.
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  7. Just to make it clear: I do not defend their approach to the divergence problem in that case, in particular their presentation.
    Not "their", but one person, and in the case under discussion, one graph which appeared in one brochure put together by the WMO. In the published literature, the "divergence problem" is, of course, openly discussed (it is scientists in the field who coined the term in the first place), comparisons of reconstructions with and without the troublesome recent decades made, comparisons to the instrumental record made, etc etc. If the divergence problem were being "hidden", etc, denialists wouldn't know about it and wouldn't've been screaming about it for years. Denialists only know about it because it's a well-known issue in the field, not because they've recently read some stolen e-mail messages.
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  8. 5) CO2 in reality is coming from warming and de-pressurizing sea water, all year round, and from the deep sedimentary basins in the northern spring
    Hey, Peter, that's very interesting. But I'm wondering ... where is all the CO2 produced by our burning of fossil fuels going?
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  9. dhogaza:"Have you read anything on how, for instance, tree ring chronologies are chosen for temperature proxy work? It's not based on "confirmation bias" based on recent warming, but rather on site characteristics and ring morphology that reflects known temperature signatures in tree ring tissue based on knowledge of tree physiology." Yes, I've read a bit. It seems to me that people have logical seeming reasons for why they choose the proxies they do, whether they actually are good proxies is another question. Mann's proxies seemed logical to him until we found that they don't work under certain conditions. CO2science.org lists quite a few different proxy studies(that I'm sure the authors believed were properly chosen). IAC, I admit to not being that up to date on the issue, perhaps you can help me resolve this question by pointing to some research where the proxies match reasonably well for both the long-term reconstruction and the current temps. Cheers, :)
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  10. People, how much time do you think we have to quabble about some academic infighting at one research outfit? The longer we argue about minutia, the longer we wait to act based on the broad body of supporting evidence from around the world, the more difficult it will be to mitigate the risk that climate change presents. And why are skeptics so quick to criticize some climate scientists for unethical behavior, yet they readily accept a few ideas or findings, often involving similar unethical practices, from the few dissenting scientists that remain? They are probably heavily biased themselves, due to a rigid belief system, financial motivations, or otherwise. We need to move forward with the more relevant discussion asking "To what degree should we mitigate the risk, using what methods, and how will we pay for it?" Anything else is just a waste of precious TIME.
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  11. #73: No, we need to acertain what the risk is before embarking on 'corrective action' which could conceivably cause more harm than good. We do not know enough and do not yet have adequate models or computing power to do more than make rough assessments. Climate change will occur whether or not we modify our output of CO2, to what extent we still do not know with any exactitude that enables us to make 'proper' decisions. Models are still, for all their apparent sophistication, unable to include many known factors that influence climate..a fact that is acknowledged by the modellers...but unfortunately not by the politicos and eco-warriors. I readily accept much of the science underpinning AGW, but I do not accept the output of the models which include so many assumptions that IMO they are pretty worthless. ( I await the deluge ).
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  12. Yes, I've read a bit. It seems to me that people have logical seeming reasons for why they choose the proxies they do, whether they actually are good proxies is another question.
    Yes, of course, that's why a variety of proxies are compared and why paleoclimatologists don't hang their hat on a single one. Compare that with how, say, McIntyre works - "Yamal! Yamal! Yamal!" - as though chipping away (ignorantly, IMO) at one proxy will make them all disappear.
    Mann's proxies seemed logical to him until we found that they don't work under certain conditions.
    The only proxy I imagine you might be talking about was the lake bed proxy from Finland which McIntyre et al trumpet "was used upside down!". Here's an interesting fact: Mann's paper stated clearly and upfront that it was though there might be problems with that proxy. Therefore he checked for robustness of his multi-proxy reconstruction with and *without* the questionable proxy. And got virtually the same result. The denialist screams about "upside down proxies!" very cleverly for the most part fail to mention that Mann himself was the first to state potential problems with the proxy, and most especially tend to ignore the fact that he tested for robustness without the proxy in question. Yet this is the proxy that is claimed "breaks the hockey stick!" and "breaks Mannian science", etc.
    IAC, I admit to not being that up to date on the issue, perhaps you can help me resolve this question by pointing to some research where the proxies match reasonably well for both the long-term reconstruction and the current temps.
    About a month ago I found a really great overview paper (probably prepared as background material for a college course or seminar) by googling. Unfortunately, I've tried several times in the last couple of days to find it again, without success. I'll try to spend more time being clever in google to see if I can find it again, and if so, will post a reference. Meanwhile - the CO2 science site is thoroughly unreliable as a source of objective information. My saying so probably won't convince you, but it needs saying.
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  13. Models are still, for all their apparent sophistication, unable to include many known factors that influence climate..a fact that is acknowledged by the modellers...
    Please name the *known* factors which models are unable to include. I'd appreciate your using your own words. Thank you.
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  14. dhogaza:The only proxy I imagine you might be talking about was the lake bed proxy from Finland which McIntyre et al trumpet "was used upside down!". Actually I was talking about the fact that his proxies don't work well for the last ~50 years. IAC, here is a pretty good overview of proxy reconstruction issues IMO: http://wmbriggs.com/blog/?p=1362#comments "Meanwhile - the CO2 science site is thoroughly unreliable as a source of objective information. My saying so probably won't convince you, but it needs saying." Well, perhaps, but it references dozens of peer-reviewed papers. Personally, my view is pretty much in line with Briggs above, so I don't put too much faith in any reconstruction. FYI, here is a reconstruction that differs from the mainstream ones. http://www.ncasi.org/publications/Detail.aspx?id=3025 My point here is that there is substantial difference in the reconstructions depending on how they are done(this makes confirmation bias a problem IMO no matter how you reconstruct temperatures). Cheers, :)
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  15. SNRatio #57 You wrote, "Why don't you check the facts before jumping to conclusions? And with explanations easily available, your reference to and interpretation of the notorious "Mike's Nature trick" either shows an ignorance I would not expect from contributors to this site, or willfull misrepresentation." Why don't you read my post more carefully. I did not say one word about "Mike's Nature trick"! I don't have a problem with the term "trick" being used, especially without a better understanding of the context. I know mathematics and science are full of "tricks" to accomplish certain tasks. Plus, I'm not a "contributor" to the site - as in a professional scientist - I'm a commenter. I stated up front that I was a layman. When you finally did address my question, you take issue with my "sweeping statement" that there is a "very serious disagreement" about the physics. I'll grant your point that I don't know all the details and so perhaps shouldn't have used the modifiers "very serious." But there is an undeniable disagreement about the physics that doesn't seem to be easily explained with "it's more about the lack of data," or Trenberth's higher standards. Trenberth asks, "What are the physical processes? Where did the heat go?" These questions are not simply answered with more data, are they? Aren't they more about a fundamental physical understanding? I deeply appreciate that you are willing to state that "the models are not adequate, and they have to be improved." And that you are "concerned that the results may have been oversold." That is my concern as well. And I must say, this is not a small thing. In a world where the primary motivator in journalism is, "If it bleeds it leads," and the most sensational stories make the front pages, and those stories motivate policy makers to pass legislation that can constrict individual choices and freedom, I think honest scientists need to shout those concerns to the heavens. So, again, your honesty in this regard is deeply appreciated. You wrote, "The positive feedbacks, while still very significant, have been smaller than implied by the models, and now they are looking into why." Recently, Prof. Lindzen wrote that the satellite data is showing that the feedback is actually negative. Are you familiar with that argument? And can you argue for or against it? Also, there seems to be some thought that the large quantities of SO2 being pumped into the atmosphere in India and China is having a moderating effect on the greenhouse effect of CO2. Could that be the case? Thanks for addressing the issue of social engineering. You wrote, "even with zero positive feedback, "carbon liberalism" will get us into climate problems pretty soon." But with zero positive feedback, won't we get only 1 degree C rise in average global temperature with every doubling of CO2? And even with the accelerating CO2 emissions of India and China, won't that doubling take tens of years? And has there been adequate study of CO2 sequestration by additional plant growth to warrant the severe GHG restrictions currently being discussed?
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  16. re #55 sorry, mate...what people write or say in magazines, newsletters, newspapers, and so on is not necessarily scientifically sound nor even necessarily science. Ollier has published proper papers in the scientific literature. The stuff you refer to isn't. The whole point of publishing in the scientific literature is that it forces a degree of scientific rigour on the measurement, analysis and presentation of the data, and that it becomes part of the scientific record to be built upon, referred to, contradicted (or sink into oblivion). If Ollier discovers something worth publishing in the scientific literature, no doubt he'll do so. (Incidentally I made a small disservice to Ollier - his last paper wasn't 2007 - he published a paper in 2008 on Deccan duricrusts, which is nothing to do with sea levels of course. He hasn't published a scientific paper in 2009 so far.) Nope Morner's comments aren't relevant. They're from some interview on some web site. We know how sea level measures are made. There's dozens of papers on this. A recent update of the subject can be found on the links to pages on this site [*]. If Morner has some problem with this he should publish on it rather than sniping in interviews. It's not scientifically interesting since it seems not to accord with the science. [*] http://www.skepticalscience.com/Are-sea-levels-rising.html and: http://www.skepticalscience.com/A-broader-view-of-sea-level-rise.html Incidentally, I wonder if you would really be happy in the world that you seem to want to inhabit, neilperth? Where you decide what seems like an expedient course of action that suits a particular political point of view, and then propagandise for this for all your worth. You might be comfortable in a world where "science" was "decided" by propagandising bullies, but you might find that their agenda didn't always match yours! To my mind, we're extraordinarily fortunate that we live in a world where a degree of independent scientific rationality exists, so that we aren't at the whim of those that consider it expedient to pervert the science on the toxicity of tetraethyl lead (say), or the role of cigarette smoking in lung cancer, or the dangers of aspirin taking in children with respect to Reyes syndrome, or the effects of CFC's on stratospheric ozone...and so on (a long litany of anti-science propagandising on behalf of vested interests). The science has pretty much always been right on these things...not sure why you think the science of the greenhouse effect is any different. I expect we'll find that the scientific understanding that develops from careful and independent thinking, researching, measuring, interpreting, synthesizing and publishing in the scientific literature is still going to be a better route to understanding, than random assertions from website interviews or articles in newsletters.
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  17. re #11 SNRatio, I agree with much of what you say. However, I’d like to comment on your post re: IPCC projections (you say they haven’t been conservative enough) and models (you suggest that they have been somewhat oversold). Since model output has been around for quite a while now we can compare model projections to real world outcomes. Likewise since the IPCC projections have been around since 1990 these can be compared with real world outcomes. (i) IPCC projections cf real world outcomes. A comparison of IPCC projections since 1990, with real world outcomes through 2006 allows us to assess their accuracy. If one looks at (i) CO2 levels [*] (ii) temperatures [*], (iii) sea level rise [*] (iv) arctic sea ice retreat [**], it’s pretty obvious that the IPCC projections have been conservative. CO2 emissions have followed IPCC projections since 1990 quite closely. Temperatures have risen at a rate that is right at the top end of the IPCC projections. Since this is a short comparison period this might just be the result of natural variation on top of a rising trend. Sea levels have risen much faster that the IPCC projections [*]. Arctic sea ice recession has occurred at a very much faster rate than the IPCC projection [**]. Obviously all of these metrics are for a rather short period (8-18 years). But if a comparison of the important metrics (atmospheric CO2, temperature, sea level, sea ice retreat) are occurring at the upper limits, or outside the upper limit of the IPCC projections, I don’t see how we can say that the IPCC projections aren’t conservative enough. Whether they’ll continue to be conservative into the future remains to be seen (very likely the IPCC sea level projections are conservative since they exclude any “non-linear” contributions from poorly predictable ice sheet dynamic responses). [*] S. Rahmstorf et al. (2007) Recent Climate Observations Compared to Projections Science 316, 709-710 [**] http://www.copenhagendiagnosis.org/download/Copenhagen_Diagnosis_LOW.pdf (ii) Comparison of models with real world outcomes This is more difficult to assess. There’s no question that models outputs have to be treated with caution. However we can compare model projections with real world outcomes. The earliest simulation (and one you comment on) is Hansens’s simulation set up around 1985 and projecting temperatures forward. This simulation has followed reality rather well (it is pretty much spot on through 2005; see Figure 2 here, a freely downloadable paper [***]). You comment that this particular model is parameterized according to a climate sensitivity of around 4 oC (4.2 oC). But this wasn’t so well-defined in the mid 1980’s nearly 25 years go. And the fact that the simulation parameterized according to a 4.2 oC climate sensitivity, matches the real world temperature progression, means that the real world temperature is rising at a rate that is consistent with a rather higher climate sensitivity than the mid range (3 oC). Of course it might not be (too soon to say); but I don’t see that we can say that model outputs are oversold when they match reality quite well… ..and that applies to the model predictions of polar temperature amplification…of water vapour feedback (before this was measured directly, Dr. Lindzen was asserting that tropospheric warming would result in a drying of the upper troposphere – he was shown to be wrong; the models were shown to be right)…of a temperature induced water vapour feedback yielding a close to constant relative humidity….the models predicted the magnitude and temporal response of temperature to the Pinatubo eruption…they predicted a fast Arctic and delayed Antarctic response to global warming…they predicted greater nighttime warming over daytime warming in a greenhouse-warmed world…they predicted a tropospheric warming that was, for about 15 years, asserted to be incompatible with the UAH satellite measure of tropospheric warming, until in 2005 it was shown that a series of systematic errors in the UAH analysis was responsible for the apparent incompatibility….the models were correct again… ..and so on.. ..it’s very easy to be sceptical of models (and we should be!), but they’ve been pretty successful so far. Whether they will continue to be successful into the future remains to be seen. [***] http://www.pnas.org/content/103/39/14288.abstract?sid=30711dcf-c67f-48ba-8983-f775d6a54d3f
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  18. Actually I was talking about the fact that his proxies don't work well for the last ~50 years.
    First of all the proxies aren't "his", he analyzes work by others. But what you're referring to is exactly the "diverenge problem", no secret, openly discussed in the literature, actively discussed in the literature. The problem is only with *some* tree ring proxies, not *all* tree ring proxies, much less non-tree ring proxies. John's going to do a post on it, I suggest postponing discussion until he does.
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  19. dhogaza #67 You wrote: "Can you explain why Trenberth disagrees with your assessment regarding policy to my (or anyone's) satisfaction if your reading of the tea leaves (sorry, "random selection" of purloined e-mail) reflects the level of uncertainty being discussed?" I did not make a random selection. I picked a discussion that reflects my deep concern about the policy implications stemming from climate science being passed off as "settled" when there are disagreements among leading AGW scientists about the physics. I have not misrepresented Trenberth's work in any way. And I don't like tea. As I said in my response to SNRatio (#78), Trenberth's question, "What are the physical processes?" doesn't seem to be "a relatively minor problem" easily explained by the "existing instrumentation isn't sufficient for researchers to close the earth's energy budget during La Niña." I'm not saying Trenberth's concerns mean that the underlying physics are "contradicted," I'm saying that he's indicating that the physics are not completely understood. And the exchange with the other scientists most definitely shows that the physics - the science - is certainly not "settled," which is my biggest concern. You will not find anywhere in what I've written that "maybe global warming doesn't exist."
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  20. Well, I just looked at the Briggs discussion of tree ring proxy reconstructions and, really, it's a cartoon description that really bears little resemblance to reality.
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  21. I did not make a random selection.
    No, not you, the people who stole the e-mail have published a random selection, and we have no idea as to what's missing or not, or how cherry-picked the published e-mails are.
    I have not misrepresented Trenberth's work in any way.
    Well, Trenberth is on record as saying that the kind of conclusions you draw do misrepresent his work. I'll take his word on it, sorry.
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  22. re #70 billbrent, I think you're discussing a sort of sub-level of uncertainty that lies underlies a broader certainty of understanding. There are (at least) two examples of this in climate science: (i) sea levels. There's rather good evidence that sea levels are rising a bit over 3 mm per year at the moment (highish certainty [*]). This must be the result of some combination of heat accumulation (thermal expansion) and mass increase (polar ice sheet and mountain glacier melt), and the summation should match the observed sea level rise if the "energy budget" is properly "closed"). Each of the latter can be estimated independently; however each of the latter measurements has greater uncertainty than the more easily measured total sea level rise. So there is a sub-level of uncertainty in the precise partitioning of sea level rise within its (less easily measured) components. The greater uncertainty in the latter doesn't negate the lesser uncertainty in the former. (ii) Radiative forcing and it's precise partitioning. This is very similar to (i) but more complex. We have rather good evidence that the net forcing from raised CO2 is equivalent to a warming near 3 oC (plus/minus around 1 oC) per CO2 doubling. The forcing is the result of a radiative imbalance between incoming solar radiation and outgoing longwave IR emitted from the earth's surface. Partitioning this to the components (solar radiation reflected to space; solar radiation reflected by surface; solar radiation absorbed by clouds; surface emitted LWIR; surface LWIR reflected from the atmosphere...and so on)...is very complex (see Figure 1 here [**]). The nett top of the atmosphere radiative imbalance that we can estimate reasonably well from theoretical analysis combined with paleoproxy analysis (that allows us to estimate the expected equilibrium temperature response to doubling CO2), is a small number that results from the summation of many large numbers. So the uncertainty in this summation of many large numbers to give a net TOA forcing has a lot of uncertainty since tiny errors in the large numbers (solar radiation emitted from the earth surface; LWIR absorbed by the atmosphere etc; see Figure 1 [*]) result in large errors in the summed TOA radiative forcing (i.e. "closing the enrgy budget"). However that doesn't mean that we don't have quite a good handle on the estimate of the total radiative forcing from independent analysis. Trenberth's problem (if I am interpreting his email correctly), is that we need to understand the component forcings and their responses if we want to assess whether geoenginering approaches will have any chance of being successful. That makes sense since geoengineering approaches (blast sulphurous aerosols into the atmosphere) affect sub-components of the total radiative forcing (.e. they mostly reduce solar radiaiton reaching the surface, but we need to know by how much before we start pumping the stuff into the atmosphere). [*] http://www.skepticalscience.com/Are-sea-levels-rising.html and: http://www.skepticalscience.com/A-broader-view-of-sea-level-rise.html [**] Trenberth, K. E., J. Fasullo, and J.T. Kiehl, 2000: Earth's Global Energy Budget. Bull. Amer. Met. Soc.. 90, 3, 311-323.
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  23. I meant to link to a pdf of the Trenberth/Fasullo?Kiehl article in Bull Am Met Soc 2009
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  24. Here's what the "decline" looks like: http://akwag.blogspot.com/2009/11/hiding-decline-what-that-really-looks.html
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  25. Thank you, Chris. I think I understand what you're saying about the broader certainty. Kind-of like the uncertainties over gradual evolution vs punctuated evolution against the broader background of the certainty of evolution itself. Right? I'll take a look at the links you provided for the radiative forcing explanation. Do you know if anyone has specifically address Lindzen's recent claim that satellite readings of LWIR data indicate a negative feedback rather than a positive one?
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    Response:

    Lindzen's claims are addressed at Chris Colose's website (another topic for a future post).

  26. Thanks for the reference to Chris Colose's website. Much appreciated.
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  27. This is off topic, but may help address some of the questions that have been raised here. On Tuesday the IPCC released an update to the AR4 for Copenhagen. You can view and/or download the file at: http://www.copenhagendiagnosis.com/ Sorry for the intrusion.
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    Response: I've posted a review of the Copenhagen Diagnosis in The Physical Realities of Global Warming.
  28. NeilPerth, Thanks for your postings. I like how when you post like you have done, the others wine how you are "cutting and pasting," but when you don't they scream "site the evidence."
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  29. Some one please show me this: it’s pretty obvious that the IPCC projections have been conservative. CO2 emissions have followed IPCC projections since 1990 quite closely. Temperatures have risen at a rate that is right at the top end of the IPCC projections" IF this is true, it would change my view from a skeptic to a believer.
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  30. "I don't see why people seem to have such a hard time understanding this issue. There is a variety of proxy data available as well as the instrumental record. There is no problem with omitting proxy data that deviates from observed results." So why don't we exclude all the tree ring data, since its be proven to be faulty?
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  31. dehogaza, I love it, when its posted in an email that he presumes is under the cover of the night, you disbelieve it, but when its clearly a public statement made with the impression he wants to give you claim. "Well, Trenberth is on record as saying that the kind of conclusions you draw do misrepresent his work. I'll take his word on it, sorry." thats fine for you, but when I see someone talk out of both sides of their mouth, they have a credibility issues with me. I am sorry that you bias lets you forgive the discrepancy when it is convenient for you.
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  32. TruthSeeker, "So why don't we exclude all the tree ring data, since its be proven to be faulty?" Never this proof appeared, not even in the "secret conspiracy emails"; on the contrary, they still prove usefull for temperature reconstructions. Instead, some trees in some sites are known (no breaking news here) to show a (relatively) recent divergence problem. And here comes the shouting on the hidden data ... "IF this is true, it would change my view from a skeptic to a believer." The data are there, the anticipated effects of warming too; you are free to distrust them if you're happy with this. I'm sure we'll not see you change your "view from a skeptic to a believer" any soon ;)
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  33. "billbrent Really apologize for mixing part of your post with another's. Scrolling up&down error. As for Trenberth, I think chris has explained things pretty well. I think you may think of this as "understanding the physics" of first and second order approximations: The first order terms, most relevant for the public warming debate, are in place reasonably well, but higher order needs more involved analysis of details. And phenomena like small systematic variations in the cloud albedo may have "huge" effects in this more detailed analysis. Lindzen&Choi's paper may turn out to have the opposite effect of what you think. You should check out Roy Spencer's comments on it on Watts Up With That, if you don't think that site is too biased towards warmism, then. You might also download and go through Lindzen's presentation "A deconstruction of global warming". That was really a deconstruction for me. But not of global warming. About "acceptable" temperature increases: I think the present rise is enough already to be of great concern, and a 1 degree rise could have huge negative impact. It very much depends on how variability develops.. With very small variability, 1 deg could be much more acceptable than with high variability.
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  34. On Tuesday the IPCC released an update to the AR4 for Copenhagen. You can view and/or download the file at: http://www.copenhagendiagnosis.com/
    Just for clarification, this isn't an IPCC update to AR4, but rather an effort by a couple of dozen researchers working on their own. As it happens, many are lead IPCC chapter authors, etc, but it's not IPCC-vetted. Which, if denialists are to be consistent, gives it *more* credibility than AR4, right, since IPCC is just an anti-science political body? :)
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  35. thats fine for you, but when I see someone talk out of both sides of their mouth, they have a credibility issues with me. I am sorry that you bias lets you forgive the discrepancy when it is convenient for you.
    He links to his relevant paper right in the e-mail you claim you understand better than he himself. Go read the paper, if you don't, you have no idea as to the context of the argument he's making in his e-mail.
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  36. Re #97. Thanks dhogaza, I was worried I had not referenced the diagnosis correctly. "Truthseeker" re #92, read the Copenhagen Diagnosis, especially the grey box on page 15. That said, as SNRatio noted, the data and facts are there, but are your willing to be open minded and unbiased enough to embrace them? Liberally cut and pasting text from other sources without any associated discussion or context is not citing evidence "Truthseeker", nor is it constructive. That said, NeilP does seem to be now engaging people, so that is a start.
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  37. # 76: dhogaza...model inadequacies: Cloud and subsequent albedo Aerosols ( not just ours but plant aerosols..terpenes) ENSO events. Alterations to WV distribution patterns caused by land use changes & deforestation. Rate of evaporation/precipitation in tropical zones. Relationship between wind & evaporation over oceans ( wind is affected by SST and SST is affected by wind speed) Current models work in pretty large cells where it is not possible to do anything more than generalise.. a good example of thjis is oceanic circulation; compare a satellite pic of circ patterns and then overlay a 200km cell and see what the models miss.
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  38. Mizimi, he/she asked you to list the known factors that the models do not include. Your list is a mish-mash of what they are not particularly good at simulating, mostly b/c of grid spacing issues. The latest AOGCMs include atmospheric chemistry, and the grid spacings are closer to one degree lat/lon. They do include/reproduce clouds, aerosols, internal climate modes, WV, ET etc etc. Read Chapter 8 in AR4. They do not explicitly simulate convection, for example. Anyhow, what the heck has this to do with the CRU email hack?
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  39. They do not explicitly simulate convection, for example.
    Actually, Model E does include a cloud convection module that among other things generates anvil-heads that break the troposphere/stratosphere boundary, if I read the documentation correctly (I've not read the underlying paper, which is clearly referenced in the code, though). It's optional, not sure when they use it. Each grid halving requires at least 8x the computing power if nothing else changes, I believe. You get four "boxes" where before there was one, thus that's 4x the amount of computation. Plus the time step must be shrunk by half since propagation times are linear to the grid size. Therefore I get 8x more computation needed. Over time they've also increased the number of layers the atmosphere is sliced into, added more physics, etc so you can see why progress in model resolution etc improves incrementally, not by giant leaps.
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  40. ENSO events.
    Models generate ENSO-like events.
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  41. Mizimi actually switched from "unable to include many known factors that influence climate" to "model inadequacies". Quite a big difference. The only thing partly true is that small scale phenomena are not simulated, but some sort of parametrization is used; which is a trick (intentionally used this word ;) ) to include phenomena at a scale smaller than the grid.
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  42. I have put together two posts analyzing two of the accusations made http://allegationaudit.blogspot.com
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  43. Apologies for my english...perhaps I should have said " unable to adequately simulate" Also of the items I listed 4 are the subject of recent research so it is not unexpoected that they are not included in current models. They do have an impact however; for example, terpene release and subsequent decomposition forms aerosols which increase low level cloud density ( apparently by up to 5%).
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  44. "unable to adequately simulate".... oh dear...split infinitives now. We just can't take seriously anything you say.
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  45. Riccardo at 20:23 PM on 25 November, 2009 TruthSeeker, "So why don't we exclude all the tree ring data, since its be proven to be faulty?" Never this proof appeared," Really, the proof appeared when they "diverged" from the temperature record, and as a result those individual entries are no longer considered good. If they arn't what evidence does anyone have that these were ever any good? Until someone can explain to me why, when their is no temperature record, they are good, but when a temperature record exist they are "to low" they will just be proof positive that these scientist are cherry picking. I am getting frustrated with the number of people telling me they were once good(supplying no supporting evidence) and then saying but now that we have temperature records they are to low.
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  46. TruthSeeker, you should be frustrated for not having looked at the science behind dendroclimatology and at the simple fact that one set of tree rings alone tells us just a little, many different cross-checked reconstructions are solid evidence. 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.
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  47. In a strange way the hacked HadCrut emails have finally convinced me that global warming is man-made :)
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  48. Disclaimed, I think you have misunderstood a bit about the precisions of predictions. You may easily get the impression that the models already are very 'truthful', but when you look closer at the actual uncertainties, you will see they are rather large as estimated now. And that may well prove to be under-estimations in some cases, without disproving the basic usefulness of the models: They are continously adjusted. Just to say that the models are not at all that good is, however, not true at all. And short-term, they are really good in lot and lots of situations now. You can get an impression of the present situation if you look at Tim Palmer's presentation in the session on "Advancinc climate prediction science" on the recent climate congress, http://www.wcc3.org/sessions.php?session_list=PS-3#doc I will also suggest Mojib Latif's presentation in the same session. He has been misrepresented as predicting 30 years without warming - that's not what he said. But when you look at his NH 21-yr moving average curve (this will filter out most solar cyclicity), there is a 60-year cycle with an amplitude of 0.1-0.2 deg that could gives us something like that.
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  49. "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?
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  50. 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?
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    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.

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