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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 117101 to 117150:

  1. Astronomical cycles
    I wonder if these astronomical cycles aren't distracting us from those published by Milankovitch. For those of you who have never heard of this before, the gravitational effects of other planets "do" affect Earth's orbital shape which changes from circular to elliptical and back over a 400,000 year period. The current shape is almost circular (an even amount of cooking on the spit). A second effect involves the tilt of Earth's axis (determines how different winter is from summer) which is currently 23.4 degrees and decreasing. A third effect involves precession (a wobble) which determines where the Earth's poles points when Earth is nearest the Sun each year. All these effects can be plotted to produce a resultant wave which would enable glaciations every 100,000 years (on average). http://en.wikipedia.org/wiki/Milankovitch_cycles The world was very skeptical about Milankovitch's theory until evidence for 100,000 year glaciations was found in ice cores from both Greenland (Century Station) and Antarctica (Vostok Station) as well as sediment cores taken from the Indian Ocean (Vema 28-238). Since then, more evidence has come from stalactites and stalagmites as well as other proxies. BTW, the ice cores are good for 400-600k years while the sediment cores provide glaciation evidence going back 700-800k years. In most instances there was an interglacial period lasting 15-20k years. http://www.southwestclimatechange.org/climate/global/past-present Earth emerged from the previous glaciation about 12,000 years ago. In all previous interglacial periods the temperature rises naturally. Warming oceans begin to release dissolved CO2 into the atmosphere which then acts as a feedback to reinforce the warming cycle (and buffer future changes). The only difference between previous interglacial periods and the current one is that this time, billions of industrial humans have precharged the atmosphere with CO2. As the oceans warm, more oceanic CO2 will be added to industrial CO2 to make things much worse. CO2 emissions from volcanoes can only drive the levels higher. { in all these lines I have omitted, but not forgotten, other GH gasses like methane, water vapour, etc. } Does this mean that other smaller cycles do not exist? No. I think there is a consensus for solar minimums (Oort, Wolf, Sporer, and Maunder) causing numerous smaller climate coolings in the last 1500 years. http://en.wikipedia.org/wiki/Sporer_Minimum CO2 levels during the previous glaciation were around 180 ppm but jumped to 280 ppm as we entered the Holocene interglacial. It is now over 380 ppm and I get the feeling that our environment is now immune to future solar minimums. The ice cores also tell us that higher temperatures are always associated with higher levels of CO2. So rather than inspecting charts of "global average temperatures" maybe we should focus a little more on the Keeling Curve. http://en.wikipedia.org/wiki/Keeling_curve
  2. Berényi Péter at 21:07 PM on 18 June 2010
    Astronomical cycles
    #0 Posted by Riccardo at 07:37 AM More generally, for n=4 the claimed 60 year cycle seems to vanish after the peak at year 1940. It's not to say that the n=4 trend has more value than the n=2, but in the end we can say that the nice cyclic behaviour seen in fig. 1 depends on the choice of the trend function. It's worth to recall that its choice is arbitrary, no physics behind it. Scafetta might not have provided physical explanation for his choice of n=2, but we can give it a try. If the long term trend described by the polynomial fit is supposed to be a response to the gradual buildup of CO2 in the climate system, and we also accept CO2 can be readily translated to "forcing" (two big IFs, but they are consistent with the mainsrteam consensus), we can make an educated guess about the correct form of the trend; not in detail, but at least about the order of polynomial to be used. CO2 increase was more or less exponential starting around 1850 while "forcing" (the resulting radiative imbalance at TOA - Top of Atmosphere) is proportional to its logarithmic concentration. Therefore this forcing has increased in a roughly linear manner since 1850. For a small forcing the climate system response can be considered linear. Any reasonable dynamic system should behave like this except for states close to some singularity. However, as climate during the last several thousand years have not shown wide fluctuations and we are still not very far from the average of this timespan, no singularity of the system can be too close to the present state. If the response of a linear and time-shift invariant system starts out as x4 for a linearly increasing excitation beginning at some instant (in this case in 1850), then its response to a step function starts as a cubic and for a Dirac delta (a brief pulse) it is quadratic. I am not talking about "climate sensitivity" here, that would involve the long term relaxation properties of the response function, it is all about the initial phase. Now. Imagine there was a general balance between incoming SW and outgoing LW radiation at TOA, so the overall balance is neutral. Then, for a brief period (let's say a month or so) this net balance is disturbed, the difference between ASR (Absorbed Shortwave Radiation) and OLR (Outgoing Longwave Radiation) increases substantially, then it is reset to zero again. How does the temperature response look like? The key point is that incoming radiative energy, if not reflected immediately back to space gets thermalized soon. If this excess heat is to stay in the system for a while, it has to be stored somewhere. But there is no other way to store it than heating up some part of the system. As there is no substance around with infinite specific heat, it implies an instant temperature increase. However, a quadratic starts from zero and for a while lingers in its vicinity. The initial phase of the impulse response can't be a quadratic, not even linear. It should start with a step. Therefore response to a linearly increasing CO2 forcing can only increase as xn if n is not greater than 2. I am not saying Scafetta's astrological speculation makes sense, but it can not be rejected on the ground stipulated by Riccardo. You have to find another way to debunk it. Of course, as always, there is an alternative. If the underlying trend is not driven by CO2 but by some other secular change capable to increase its forcing in a cubic (as opposed to linear) rate, Scafetta is debunked for good. However, the very existence of this mysterious agent is an immediate death blow to consensus climate science, so if I were you, I would not take the tack.
  3. Astronomical cycles
    Chris #39 Each 'well established' forcing must be looked at in detail - and those from Fig 2.4 of IPCC AR4 are not all that well established. Dr Trenberth's 0.9W/sq.m TOA imbalance is derived from "MODELS" - not direct measurement and in particular cooling forcings have wide error bars. With little storage in the atmosphere, the integral WRT of the energy flux imbalances ie. heat energy, must show up in the oceans. Chris, this “nice AGW trend” is not looking so nice when the purported energy flux imbalances are not showing up in OHC for the last 6 years and probably not much in the last 16 years. Unless this 'imbalance' heat shows up in the oceans; warming is not happening and AGW theory is in serious doubt.
  4. Andrew Bolt distorts again
    Whew! What an awful time to be a climate scientist. The top is spinning down but it still wobbles through equilibrium on every rotation. Then it drops a bit and the climate deniers can absolutely get good data that there is no warming. Another half-cycle and it comes across equilibrium...but on the way UP, AGW scientists can absolutely qualify and quantify the shift. Both groups can obviously back-trend and find something. Humans are good at that. The only proof that anyone will ever accept...and many probably won't... is the Venus Syndrome. When climate forcing tips us into a continuous and irreversible feedback loop. What will the precursor to that look like? What marker will unequivocally show the end of our ability to stop our own extinction event and grasp that it has begun? I believe we are there, but I am not the Oracle of science. Yet there must be something specific we can recognize and leave debate mode for an attempt at survival.
  5. Astronomical cycles
    HumanityRules at 15:05 PM on 18 June, 2010
    ”I'm interested in the HADCRUT3 data in fig2. It overall trends up but with periods of rise/fall/rise/fall/rise. Is this not real? Does that need an explanation? This is surely an up trend with a cycle? if not what is the alternative explanation for the phases? Surely this is what AGW wants? An a clean uptrend that mirrors the uptrend in CO2 emmissions? Surely AGW wants to remove the mess of interferring factors (such as solar,volcanos and cycles) to leave a nice AGW trend?”
    So many question HR! But you’ve had them answered before I think. The 20th century warming trend can be addressed in the manner you speak of, in two essentially equivalent ways by considering the physics involving known forcings and internal variability. Thus one can independently assess the natural contributions to the 20th century and contemporary warming profile and subtract these from the warming profile “to leave a nice AGW trend”. If one does that, then according to Swanson et al (2009) [*] “Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century.” The other means of doing this is to model all of the contributions to the 20th century warming profile by parameterizing their contribution according to best estimates using known physics, and assess the extent to which these reproduce the warming profile. A couple of examples of this approach can be found here [**] and here [***]. In this case the “nice AGW trend” is established first according to known physics and included in the model, rather than "falling out" of the model as a remainder left over after removing all the contributions from internal variability a la Swanson et al.. In all of these cases the essential features of the 20th century and contemporary warming can be understood in terms of rather well understood natural and anthropogenic contributions. It’s not obvious how another phenomenological numerological analysis that lacks a basis in physics and that doesn't anyway match the empirical data very well is going to add to our understanding. That's not to say it isn't interesting. But fundamental scientific steps are missing here, namely (i) a mechanism for the supposed effect, (ii) its independent quantitation, and (iii) some physical explanation of how this "over-rules" all the known physics otherwise described in the papers cited here and elsewhere. [*] K. L. Swanson et al. (2009) Long-term natural variability and 20th century climate change. Proc. Natl. Acad. Sci. 106, 16120-16123. (see also) Zhang, R., T. L. Delworth, and I. M. Held (2007), Can the Atlantic Ocean drive the observed multidecadal variability in Northern Hemisphere mean temperature? Geophys. Res. Lett., 34, L02709 [**] Hansen, J. L. et al. (2005) Earth's energy imbalance: Confirmation and implications. Science, 308, 1431-1435 [***] Lean, J.L., and D.H. Rind, 2008: How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett., 35, L18701
  6. Astronomical cycles
    HR, that still doesn't change my original point which is this-*if* the Astronomical Cycles Scafetta refers to have acted on the climate before, then we should see *evidence* in the climate record to support it. Now we *do* see evidence of past warming, but this warming was primarily underpinned by a change in the level of Insolation-whether due to increased solar activity (such as the Roman Warm Period & the MWP) or the Earth traversing slightly closer to the sun (the various interglacials). Now if planetary alignments were the actual cause of the change in solar activity, then we'd expect to see increasing solar activity in the current "cycle"-yet the truth is *we're not*-solar activity peaked in the 1940's & has been gradually trending downward ever since. Until someone shows me the some outward *sign* that the sun is being directly impacted by planetary alignments, then Scafetta's work is just an intriguing exercise in mathematical formulations-it most *certainly* isn't a valid explanation for the vast bulk of late 20th century global warming.
  7. Astronomical cycles
    HumanityRules, I did not proposed a different mathematical game, I intentionally played the same game as Scafetta to show its inherent weakness using his own rules. As for the rise and fall, they're real and the widely accepted explanation is (roughly) that it's the sun plus volcanic activity (which no one want to disregard) with anthropogenic forcing dominating the final rise up to today. Disproving this explanation is what Scafetta was trying to do, unsuccessfully in my opinion. As for variability and apparent cycles, it's well assessed that a good part of the measured variability is due to ENSO, a cause of cyclic variability no one overlooks. Once it's effect is removed not much is left and no evident cycles can be spotted. shawnhet, if you assume the reality of the 60 years cycle and fit trend plus the cycle to the data you indeed have good reason to trust it. But the existence of the cycle is what he was trying to demonstrate, it's a tautology to assume it's real to demonstrate that, well, it's real. Indeed, Scafetta correctly first fitted his parabola and then the cycles keeping the parabola fixed. He did not explicitly said he did it this way, I found out empirically.
  8. Stephen Baines at 16:16 PM on 18 June 2010
    How climate skeptics mislead
    BP "In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done." The key question here is what exactly is the "job to be done." One level of certainty is needed to know if an increasing trend in temp exists and another to know whether the increase is quantitatively similar to a known energy imbalance. But obviously we will never know "exactly" what the change in land or sea surface temp is. Even though we believe an exact number actually exists, we can only approximate it. Should we then say we know nothing? The closest thing in the natural (as opposed to mathematical) sciences to the deduction that BP craves is what Platt called strong inference. It involves developing a suite of alternative hypotheses that at least try to address a phenomenon from all sides and then constructing (and conducting) focused experiments to determine which among them hypothesis describes the phenomenon of interest. It's the closest to what BP would recognize as deduction - defining a range of possibilities that encompasses all possible outcomes and evaluating which provides the more probable fit to the data. In some ways we have a perfect set up for strong inference in the case of AGW. AGW provides a coherent explanation for changing climate patterns over the last 50 years that is based largely (although not exclusively) on CO2. The models developed seem consistent with climate changes in the deep past and interaction between atmospheric composition and climate on other planets. Thus we have a body of theory about drivers of climate and a prediction (actually many if you consider the various models) for the future. There are also competing explanations (it's the sun, its PDO or El Nino, its UHI effect) that tend to make somewhat different sets of predictions by emphasizing specific aspects of the energy/climate system. It would be immensely interesting to run an experiment to determine which is the winner here. Of course the problem is that we can't actually control what happens next, we don't have replication, and we don't have a control. What's more we don't actually want to do the experiment if it turns out a certain way, as we are part of the experiment. So the question is, which treatment should we do given that we have one replicate, and we're living on it. We really have no choice but to place odds on which hypothesis is likely to make the best prediction so that we can avoid, or plan for, the possible consequences. That means assessing the relative merits of the different hypotheses up until now. As a scientist I appreciate BPs insistence on precision and his skepticism, extreme as it is. However, if I'm laying a bet that I don't want to lose, I will use all the information available to me to make the best decision. Because AGW provides a very complete explanation of changes to a wide range of variables, it seems a good bet to me compared to the others, most of which were discarded long before they were raised from the dead again...and again. I have to go on a research cruise for a month so I'll be signing off for a while. It has been a pleasure to read all these cogent and mostly civil discussions. Don't have too much fun while I'm away!
  9. Astronomical cycles
    Just so I am clear here - am I supposed to understand that regardless of the exponent of n, we would still be left with some version of the underlying SCMSS cycle that was found by Scafetta? If not, isn't this analysis a trifle incomplete? If Scafetta's detrending plus SCafetta's cycle match up pretty well with the observed temp records, then that is a decent reason to use it as a basis to predict future temps. However, detrending without an explanation of the causes of changes in the detrended data doesn't tell us much of anything. Cheers, :)
  10. HumanityRules at 15:05 PM on 18 June 2010
    Astronomical cycles
    33.Albatross I think I accepted that the IPCC says 1950 onwards is most, it's 1970's onward were they suggest almost all. So nature has a nett cooling affect for the past 50 years? So the IPCCC does seem to completely reject the presense of 60 years cycles with 1970-2000 being the up stroke of the cycle? It seems this article is suggesting that in playing a mathematical game Scaffetta is identifying a cycle, it should equally be stated that Riccardo is questioning this with his own little mathmatical game. I'm interested in the HADCRUT3 data in fig2. It overall trends up but with periods of rise/fall/rise/fall/rise. Is this not real? Does that need an explanation? This is surely an up trend with a cycle? if not what is the alternative explanation for the phases? Surely this is what AGW wants? An a clean uptrend that mirrors the uptrend in CO2 emmissions? Surely AGW wants to remove the mess of interferring factors (such as solar,volcanos and cycles) to leave a nice AGW trend?
  11. Astronomical cycles
    'So what you're saying is that it is controversial that the 20th century is made up of 60years cycle with an underlying up trend? I can see it's a short time period to recognize a cycle'> Of course I its controversial. Its not controversial that trend is overlaid with ENSO quasi-periodic cycle. McLean et al kindly showed that you can explain much of the cycle that way. But a longer term cycle? Nope. The alternative explanation that it is response to forcing make more sense physically since no natural cycle in energy flow has so far been discovered. Perhaps also look at this Cyclical?
  12. Astronomical cycles
    Humanity Rules @32, "At risk of repeating myself it seems the IPCC rule out any component of the 1970-2000 temperature trend being part of a natural cycle." Not true. From the IPCC, AR4: "Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.[7]" Also, "it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing and very likely that it is not due to known natural causes alone. During this period, the sum of solar and volcanic forcings would likely have produced cooling,..." Also, read this There is more in the Copenhagen Diagnosis. Also consider this new paper
  13. HumanityRules at 14:00 PM on 18 June 2010
    Astronomical cycles
    scaddenp So what you're saying is that it is controversial that the 20th century is made up of 60years cycle with an underlying up trend? I can see it's a short time period to recognize a cycle and confused by other factors but I had it in my head that wasn't controversial. The HADCRUT3 data in fig2 seems to show rise/fall/rise/fall/rise (with an underlying up trend) NewYorkJ I was referring to the IPCC's statement on post 1970's data. If late 20th century is almost all AGW then there is no room for an upstroke on a natural cycle as suggested by figure 1. Marcus I did say natural cycle with an overlying trend and Scaffetta detrends the data for a reason. I think one of the questions raised by this is not if all the late 20th warming can be explained by natural cycles but whether we need to unpick the complex factors affecting the global temperature. At risk of repeating myself it seems the IPCC rule out any component of the 1970-2000 temperature trend being part of a natural cycle.
  14. Peer review vs commercials and spam
    Oh dear, more assertions that peer review reinforces the 'consensus', that reviewers abuse it to keep rival interpretations out to corner grant money, or that they bow to the opinion of 'powerful personalities'. FYI, there is no group that love a proper controversy more than scientists. And by 'controversy' I don't mean fake ones like Creationism vs Evolution. They are inherently anti-authoritarian, and while most students probably start out thinking their supervisor's interpretations are perfect, by doing their own research they soon figure out that they're not.
  15. How climate skeptics mislead
    Berényi - you continue to confuse probability theory (known universe of results, absolute identification of each case, and the likelyhood of one result from that limited known universe) with the first definition of probable, supported by evidence strong enough to establish presumption but not proof (a probable hypothesis). You have also not, as far as I can tell, read either e's or my links to inductive arguments, the basis of (to list a few) climate theory, evolution, and most of our every day decisions - not to mention how we judge competing theories every time they arise in science. We can't know all possible outcomes; we have to decide based on the strongest evidence and experimentation we have. I will be the first to admit that inductive logic is a point of contention. Every philosopher of science who has written on the subject has concluded that (a) it's not absolute proof, or an absolute conclusion, as deductive logic provides, and (b) bloody hell, we need it anyway, since we cannot know all cases, and must make decisions based on whatever experimentation we have been able to conduct - without knowing the entire universe of results. Most people take an inductive theory, and apply deduction to support it - there's rarely an acknowledgement of the inductive basis of many of the premises used in the deductive arguments. Irregardless: As I stated quite some time ago, on a completely different focus, even if your objection to the GHCN data is valid, a point of some contention, that does exactly nothing to disprove the many many other independent lines of evidence that support global warming and indeed AGW. In fact, this is now a poster-child demonstration of the skeptic approach of picking one line of evidence, bringing up some objection (of varying strength), and then stating that based on that singular objection to a particular data set that an entire theory supported by many lines of evidence is now suspect - that all supporting lines of evidence/data sets (such as the several satellite sets you refer to) are therefore invalid. Just as John Cook described in this topic, at the top of the page! Issues with a single line of evidence are limited to that line of evidence, and only propagate to derived data - and the satellite data sets are very clearly not derived from the ground station data. Single data line issues don't affect a general theory unless a significant number (again, a judgement call) of the supports for that theory are invalidated, or that a better explanation (simpler? parsimonious? Fewer crystal spheres?) is found for them. Thank you for the demonstration, Berényi.
  16. Berényi Péter at 12:31 PM on 18 June 2010
    How climate skeptics mislead
    #203 Tom Dayton at 11:31 AM on 18 June, 2010 At least, you were wrong if you continue to insist that scientific decisions are binary, so that "postponing judgment" means refusing to make a decision at all until, when you have removed all uncertainty from your measurements, you make your decision with 100% certainty. John, who said all uncertainty should be removed from measurements? That's not even possible. On the other hand if uncertainty of judgment is due to poor measurability, of course it is the first thing to do to improve measurement. You know perfectly well that you do not have to remove all uncertainty from measurements to be able to form true propositions. If you measure the diameter of a speck and find it to be 1 cm, measurement error is 10%, you can be certain the speck is smaller than 1 km, can't you? On the other hand if you measure 973 m, you have to have a closer look and refrain from judgment until it's done. It is perfectly legitimate to say I-do-not-know. And yes, a scientist do not have to make public decisions. It is not his job. Otherwise of course he makes decisions all the time as anyone else. But there is nothing particularly scientific in them, not even in the case he makes a decision on performing a specific experiment.
  17. How climate skeptics mislead
    BP, "What kind of question is that? Some obviously do. Others not. The same with non-skeptics." A reasonable and relevant question. Let me put it to you this way. Do you approve of the propensity of "skeptics" to distort, misrepresent and confuse the science of climate change? Monckton being one example. So please elaborate on your stance. I would take issue with your use of the quantifier "some" when referring to skeptics misleading. Have you not been paying attention to the content posted at "skeptical" sites such as WUWT, or the distortion but certain media outlets of late? There is a definite propensity for skeptics to intentionally mislead or embark on sub-par science. In fact, there are simply too many examples to cite here. There is also a definite tendency for "skeptics" to try and distract attention from the compelling convergence of multiple lines of evidence in the post by John. That point is clearly irksome for "skeptics", so it seems their tactic is to distract or obfuscate, and I might add that has been beautifully illustrated by the wayward discussion of the UHI on this thread (that being but one example). "e" at 202, fair enough :) Are you or anyone else here familiar with the work of Giere, specifically his book "Understanding Scientific Reasoning"? BP, maybe something to you to consider reading?
  18. Astronomical cycles
    HR, if the last 60 years is all part of some natural cycle, then we should be able to detect identical trends during previous 60 year cycles. The reality is, though, that we can't. By Scafetta's analysis, the last 60 year cycle was 1890-1949, but I've already shown how-in spite of a large growth in average sunspot numbers-the rate of warming was only +0.06 degrees per decade. Compared to +0.11 degrees per decade for 1950-2009, in spite of a fall in sunspot numbers over this time period. That suggests to me that something other than natural cycles is at work!
  19. How climate skeptics mislead
    BP, the lofty traits you ascribe to science apply only to formal logic and mathematics. Perhaps science is not what you thought it was? Many philosophers to this day have grappled with the problems with science you discuss. In my mind, the only reason necessary to trust in such a vague and uncertain endeavor is that it works. Planes fly, cars drive, diseases are cured, etc.
  20. Berényi Péter at 11:32 AM on 18 June 2010
    How climate skeptics mislead
    #199 Albatross at 09:49 AM on 18 June, 2010 please, at least have the gumption to call foul when "skeptics" mislead Foul. Or do you disagree with John's (and others') assertion that "skeptics" mislead? What kind of question is that? Some obviously do. Others not. The same with non-skeptics.
  21. How climate skeptics mislead
    BP >It is made to look scientific while in fact it is just plain old-style guesswork. Yes it is guesswork BP. But it is an educated guess. This is how predictive science works my friend. We can never know the future with certainty, we can only guess at it based on our uncertain knowledge.
  22. How climate skeptics mislead
    Berenyi Peter, you were wrong in stating that "In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done." At least, you were wrong if you continue to insist that scientific decisions are binary, so that "postponing judgment" means refusing to make a decision at all until, when you have removed all uncertainty from your measurements, you make your decision with 100% certainty. Science never has worked that way, and it cannot work that way. Not in any scientific field. Uncertainty of measurement never can be reduced to zero. More importantly, fit to measurements is not the only criterion by which scientific theories are evaluated, and evaluating by using that whole cluster of criteria is a complex human judgment that involves yet more uncertainty and, inescapably, more or less subjectivity. I am a trained scientist, as are many of the posters and commenters here. Your insistence that you are the only one who knows the definition of science has become annoying rather than being simply naive. You don't have to trust our assertions. Just read good science journalism, such as Science News or Scientific American. In nearly every story you will see a range of opinions from scientists who are specialists on that topic. Some even claim to be 100% certain that the theory is correct, whereas others say they are "pretty sure," some say their certainty is 50%, and often there are others who insist they are 100% certain that the theory is wrong! And every time there is a discovery or theory that "overturns" a field, that means the majority of scientists in that field previously were certain about something they now are certain is wrong! You also wrote "In real life this procedure is not always practicable, because decision is urgent and resources are lacking. In this case you have to make-do with what you have. But do not call that science please." But science is "in real life"! Science always requires decisions, even if those decisions are whether to continue to try to validate a theory or abandon it--whether to do one more experiment or analysis despite the counter-evidence or lack of evidence that has been gathered so far, whether to even spend more time thinking about it! There is a range of "urgency" and a range of "resources," so you are correct only insofar that in some cases the "decision" about a theory (or even whether to trust an observation) is an armchair kind of decision. In those cases, scientists do indeed officially reserve judgment. But in practice they actually do make decisions about whether to continue to investigate, and rarely will they refrain from passing judgment at all; instead they will state a judgment with caveats. Science is what scientists do. You should read more about philosophy and history and sociology and anthropology of science, and even more than just Popper's opinions. Scientific decision making and probability are merely subsets of the topic of judgment and decision making, about which you need to learn; try, for example, David Hardman's book. (I apologize if this comment is too long or strident. I take the coward's way out by blaming a glass of Moylan's "Kilt Lifter" Scottish style ale.)
  23. How climate skeptics mislead
    Sorry Albatross I agree this conversation has taken some esoteric turns, but since the theme of this post is the "consensus of evidence", I feel that a philosophical discussion of why such a consensus has relevance is somewhat on topic. In any case I can't help myself but indulge BP in this discussion a little bit more, I apologize if I'm just running in circles here. I think it's pretty clear he disagrees with you by the way that skeptics mislead. BP feels that a focus on minute particulars is far more relevant than weighing the totality of evidence. I'll defer to John's judgement as to whether this conversation needs to end where it stands. BP, That was a very interesting post, but it only serves to weaken your own arguments. You write that often in science we start with a huge inductive leap, then work backwards deductively establishing evidence for the general principle. I'll agree this is often the case, but not with climate science. AGW fell out of an attempt to reconstruct the behavior of our climate from our low level understanding of physical processes. It is clearly a theory borne out from inductive methods. Early attempts did try to deduce our climate's behavior from broad generalizations, but these attempts were met with failure (take a look at that link, it's a good read if you haven't seen it already). Furthermore, in your own entreaties you have urged us to stop looking at the "big picture" and working backwards, rather you'd prefer we work out the individual pieces and see where it takes us. You propose a method that is clearly inductive when applied to the general theory of AGW. Why then can we not evaluate your approach as such? > We can never be sure if these signs give us truth or not. However we have no choice but consider them true until proven false (by experiment or observation). Utter nonsense BP. You are now in direct contradiction to the basic principles of scientific skepticism (and of course, all modern judicial systems). Positive claims require positive evidence before we even entertain the idea that they are true. I propose to you that there is an invisible unicorn standing behind you right now. Did you honestly have to wave your hands in the air before assuming that my claim is false? >If something is 95% true, it may take quite a lot of counterexamples to get one convinced it must be false after all. Yes. This is exactly how the scientific method is supposed to work in fields where the evidence itself is complex, and is perfectly consistent with how theories have historically been modified or replaced. In such fields, each piece of evidence standing on its own is questionable. Only when you take the evidence in summation does a case for general theory arise. If a single piece of complex evidence can unambiguously falsify a theory, then I again submit that observations of SST's falsify your claims on UHI. >we are doing science and in this fine tradition you should let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil. That communication has been a direct and clear "YES": based on the mass of all current evidence, AGW is true. It is the "skeptics" that have harped on the question of uncertainty. >In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done. There is no such thing as "getting rid of uncertainty" in science BP, I thought we had established that fact already. As such, the "job" is never complete and your claim implies we will never make any judgements whatsoever. If you honestly believe there is such a thing as 100% certainty (the equivalent of saying all uncertainty has been removed), then there is no point in continuing this conversation.
  24. Berényi Péter at 11:13 AM on 18 June 2010
    How climate skeptics mislead
    #183 doug_bostrom at 11:40 AM on 17 June, 2010 It seems to me that overzealous application of Kolmogorov's axiom system could lead us to effective paralysis Yes. In real life it is imperative to be able to handle obscure issues. However, the way we do it should not be confused with applications of probability theory in the strict scientific sense. This is exactly the problem with the way IPCC presents its assessment system with guidelines for quantification. It is made to look scientific while in fact it is just plain old-style guesswork. Insufficient knowledge of sample space (field of possible events) is a serious issue. There are several extremely complicated systems like commercial airplanes or nuclear power plants where failure is not tolerated easily. Guys are developing sophisticated models to assess probability of failure but the thing is, retrospective analysis of actual accidents almost always uncovers some momentum or coincidence of otherwise independent chains of events, that no one expected, therefore it was missing from any previous risk assessment scheme as well. The rule is rare events happen often. There is an enormous tail of the probability distribution spanning unexplored expanses of the sample space. In this region each individual event has a vanishingly small probability, but all taken together, some of them is to be expected to happen rather soon. There is no good scientific way to handle situations like this. You have to rely on structural safety, engineering expertise, responsibility and common sense. There is another issue. This is personal communication from a guy trading in Decision Theory. In fact it happened in a pub, drinking beer, so I don't have references. Anyway, he described an experiment where subjects were asked to play a game and they were actually payed some small money for winning. There were a dozen or so marbles, all yellow, except one, which was blue. These were put into a black velvet bag in front of the subject, so he could see and count them. Then the experimenter pulled the marbles out of the bag one by one and the subject was to bet on its color in advance. Later on the betting strategies people followed were analyzed. There is a known optimal strategy for this game and it was found their performance was seriously suboptimal. The guy (the one I was drinking beer with) wondered why was it so. Well, there was a quirk to the experiment. The black velvet bag had a small hidden pocket inside and the experimenter trained himself in advance to be able to put the blue marble into the pocket in plain view without being noticed. This way he could always invariably present it on the last turn. It made sense, because this way he had more data (as soon as the blue marble is out, there is no uncertainty left in the game whatsoever). I told him the subjects probably guessed he was cheating on them and adjusted their strategies accordingly. He thought he had taken all the necessary precautions to prevent this, each subject played the game only once, they were not allowed to communicate with each other, and he, being an amateur magician otherwise, could really perform the cheat undetected. Well, I told him people have a general knowledge of psychologists cheating in experimental situations like this, so he has to look for the specific cheating model people had in their mind making the betting strategy they have actually followed close to optimal. So did he. Not in the pub, but during the days following. Next week he came up with a probability distribution for the blue marble along consecutive turns that made the average observed strategy optimal. It was tail-heavy, that is, looked like some mixture of the correct uniform distribution and the actual one, where the blue marble was always the last one. He could not repeat the experiment without cheating, because by then it was common knowledge among the students that the last one is blue. No one knows what has actually happened. There is a small possibility of the subjects communicating their experiences to the ones still waiting. But the distribution has not looked like that. It didn't have a single spike at the last turn, but a rising slope. People may be too dumb for this game. But it is also possible the sample space they had in mind and on which they have (mostly unconsciously) computed their strategy was wider then it was supposed to be and on top of possible configurations of marbles also included guesses on ways they might be cheated on. After all it can happen anytime, not only in controlled experimental situations. There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
  25. Doug Bostrom at 11:02 AM on 18 June 2010
    How climate skeptics mislead
    Thank you johnd, you extended the life of my analogy by another few miles. Notice how John seized on a single indicator or metric and began to work it as a source of doubt? We've also got the strange clattering from the engine but let's ignore that aberration and focus instead on how the flickering oil light might not be telling us anything because it's an indirect diagnostic of the oil level. Later-- after we've wrestled the oil pressure light to the ground-- we'll forget about lubrication quality and instead exclusively quibble over what a mechanical thrashing noise may or may not tell us about the engine. Don't ever consider the symptoms as a whole because that might lead to a conclusion. This form of abstract mental disintegration will lead to physical engine disintegration Berényi Péter, the fossil fuel gas tank is rapidly approaching empty and there's no fuel station in sight. The car's shortly going to run out of gas leaving us stranded regardless of the actual state of the oil pan. The anthropogenic warming thing is one issue, fossil fuels are another. The two are closely related but fossil fuels are on their own trajectory quite apart from climate problems.
  26. Astronomical cycles
    "The fact that the IPCC says that almost all late 20th warming is due to GHGs" The IPCC is actually quite conservative and nuanced. Here's what they conclude: "Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic" "Most" meaning >50% and "very likely" meaning >90%. Interestingly, Scafetta makes a similar statement in his latest: "This estimate should be compared with the IPCC’s estimate that 100% of the warming observed since 1970 is anthropogenic." Perhaps there's a different statement in the IPCC report that you both are referring to, but this appears to be another reason to suspect a sloppy/poor review of this paper.
  27. Astronomical cycles
    HR - its all to easy to say "could be a natural cycle" which is somehow supposed to be a causeless phenomena too mysterious to penetrate. However, tomorrow's weather has physical causes; the ESNO has a physical cause etc. Where is this other mysterious cycle which somehow has rates of change so much higher than we are used to? Now it might exist - but the alternative hypothesis that the temperature record can be understood entirely on the basis of forcings plus some internal variability seems one how of a lot stronger and the best basis for a risk assessment. How much up trending would it take for you abandon the natural cycle hypothesis and what would it cost us by then?
  28. HumanityRules at 10:09 AM on 18 June 2010
    Astronomical cycles
    Philippe Chantreau at 16:22 PM on 17 June, 2010 Lies, damn lies and... science. Scaffetta puts forward an analysis that is there to be questioned. That's not lying that's stepping into the unknown, that's science. Good post Riccardo, as usual it leaves me with more question than answers. I guess it is not controversial to state that the 20th century temperature record could be understood as cycles overlaid by a trend? Understanding the nature of those cycles seems important. Do you know any other theories out there regarding the cycles? How do other's try to separate out the natural cycles from the temperature trend? The fact that the IPCC says that almost all late 20th warming is due to GHGs suggests to me that they do not recognize that this period is part of the upward trend of one of these cycles? Is that true? Finally only last week I was trying to work out the amplitude of the natural cycle. Scafetta seems to put it at ~0.4oC. I was interested in this in connection to the supposed affects AGW would have of seasons, phenology, extinctions etc. It's interesting to consider that species naturally would have to cope with 0.4oc changes every 30 years if Scaffetta's analysis was true. Adaptibility within species (even over a short period) does not seem to be figured into the more doomsday scenarios.
  29. How climate skeptics mislead
    John if you don't mind, I'm going to take some initiative here. BP et al., you have steered us way off topic. As fascinating as the philosophy behind the science is, it should not detract from the fact that "skeptics" show a propensity to distort and mislead when it comes to the science. Perhaps BP you are trying to detract from that inconvenient fact? BP, please, at least have the gumption to call foul when "skeptics" mislead, which is actually the topic of this post. Or do you disagree with John's (and others') assertion that "skeptics" mislead?
  30. Astronomical cycles
    Seriously JohnD, if you're going to come here & debate the issue, then at least try & make an effort! Dusting off tired old "skeptic" arguments & passing them off as new might work in the denialosphere-or even in the blogs of the Mainstream Press, but you'll need to do a bit more leg-work here! For the record, the usual convention in determining decadal trends is to use *actual decades* (say 1980-1989). If we do that, then we get the following warming trends: 1970-1979: +0.06 degrees/decade; 1980-1989: +0.055 degrees/decade; 1990-1999: +0.16 degrees/decade; 2000-2009: +0.13 degrees per decade. Now average sunspot trends for these decades were: +2/year; -5/year; -9/year & -14/year. So that *really* makes your argument look incredibly shaky JohnD! Time to go home & do your homework I reckon!
  31. Berényi Péter at 09:22 AM on 18 June 2010
    How climate skeptics mislead
    #193 kdkd at 05:53 AM on 18 June, 2010 how to deal with uncertainty and poor measureability properly In science the standard practice is to get rid of uncertainty by improvements to your measurement system, postponing your judgment until the job is done. In real life this procedure is not always practicable, because decision is urgent and resources are lacking. In this case you have to make-do with what you have. But do not call that science please. your comments are showing your susceptibility to the Dunning-Kreuger effect So are yours :)
  32. Berényi Péter at 08:54 AM on 18 June 2010
    How climate skeptics mislead
    #195 doug_bostrom at 07:33 AM on 18 June, 2010 I ought to pull off and check my oil level Except your car is the world economy, already on a bumpy road along the river, on a floodplain with swamp on both sides, water level is rising fast so you have to reach high ground as soon as possible. Make your choice.
  33. Astronomical cycles
    JohnD, The question remains why you chose 1998-- a year frequently cited by "skeptics", some erroneously, as the warmest year to date in the instrumented record. The follies of "cherry-picking" start dates, has been discussed ad nauseum. The only reason I chose 1986-1998 is because you chose 1998-present (~12 years), so I selected the 12 years prior to 1998 so that we would at least be comparing trends determined using the same number of data points. To calculate stat sig. trends one needs at least 15 years or so of data in the GISTEMP data. The trend in GISTEMP from 1978 to 1998 (i.e., using the dates that you suggested @24) was +0.123 K/decade, compared to +0.134 K/decade from 1998 to present. The trend from 1978 to preset is +0.168 K/decade. So, the trend between 1998 and present is positive, and even greater than that observed between 1978 and 1998 (although the difference between the two is probably not statistically significant). Anyhow, your suggestion that global temperatures have been stable since 1998 or have even cooled since 1998 is simply not correct. Hansen et al. have a paper (which you can download from his web site) in which they demonstrate that the long term rate of warming in the GISTEMP until present has not showed signs of a (prolonged) slow down in the warming. It is a very interesting paper and well worth reading if you have the time (it is rather long).
  34. Is the long-term trend in CO2 caused by warming of the oceans?
    scaddenp: Sorry I don't understand what you are saying. Add a linear trend to what? No need for magic. The equilibrium is between the bottom of the atmosphere and the top of the ocean, and if the ocean needs to add CO2 to the atmosphere to keep equilibrium, it will add it. If it needs to sink it, it will sink it. If you dump CO2 into the atmosphere more quickly than the change in the surface temperature would demand, it sinks it. All: Many thanks for all your contributions to this thread. Clearly, I did not do a good enough job of presenting my model. Time to do a rewrite instead of trying to address your questions one at a time. Keep your eyes on WUWT!
  35. How climate skeptics mislead
    doug_bostrom at 07:33 AM, doug, perhaps your oil level may be low, but there is no direct correlation between a flickering oil light and the oil level. They may coincide much of the time, and be plotted on a graph, but the mechanism that drives each are separate with only indirect links. PS. Don't trade in the car yet, there is a lot of mileage left in the analogy tank.
  36. Is the long-term trend in CO2 caused by warming of the oceans?
    Lon, my point is that you add a trend to the data so it was even an anti-correlation between temperature and co2, you would still be able to derive your model. ie it makes no statement about trend. On top of this, you still have to explain the magic by which co2 comes from ocean while ocean co2 increases and how to reproduce the atmospheric isotope data with an increase in ocean CO2.
  37. Doug Bostrom at 07:33 AM on 18 June 2010
    How climate skeptics mislead
    Retracing our footsteps back from the interesting and informative and completely necessary conversation on epistemology, I'm still left with hints about climate behavior that my feeble brain can readily analogize to a more prosaic level. My vehicle's engine is making some unusual clattering noises. The oil pressure light is flickering. I've not checked my oil level recently, I can't really remember how many miles ago. I know my car consumes a certain amount of oil but my notion of exactly how much oil is consumed per mile is hazy. None of these things are a certain indication that my engine is about to burn up. The clattering could be a collapsed lifter, the flickering lamp could be a short. My assumptions about a potentially diminishing quantity of oil are hazy at best. I should add, this is all behavioral information from my actual experience with one of my cars. So none of the indirect information I have about what's going on under the hood is anything like conclusive when I consider each clue in isolation. I've had a clattering lifter before. The engine wiring harness is in poor shape and I've seen the oil pressure light flicker and even light solidly in past only to find a full oil pan. My last measurement of oil level is even more uncertain, I have only the vaguest notion of how much oil ought to be present. Taking all that information together, however, I can form a reasonably useful judgment that my vehicle is about to undergo a drastic change and I ought to pull off and check my oil level. In all probability I'll find the level to be critically low. For me, that's the model of what I'm seeing with regard to climate. We've got all sorts of signs and portents pointing more or less in the same direction. None are perfectly reliable, some are quite imperfect, but it would actually be unreasonable to ignore the overall message.
  38. Doug Bostrom at 06:12 AM on 18 June 2010
    How climate skeptics mislead
    Berényi Péter while I still cannot seem to arrive at a state of paralysis based on your thoughts and opinions, that was really nicely written post. Thanks also to 'e' and 'KR.'
  39. How climate skeptics mislead
    BP #191 This latest comment, and others really does look like your own training has ill equipped you to understand how to deal with uncertainty and poor measureability properly. Which is leading me down the track of thinking that rather than trying to actively mislead, a lot of your comments are showing your susceptibility to the Dunning-Kreuger effect.
  40. How climate skeptics mislead
    Differences in temperature anomaly (10-year running mean) in nearby stations. Base period is 1971-2000. Sniezka is mountain without UHI effect and Wroclaw is city with pop= ~600000.
  41. Podcasts, interviews and Monckton bashing
    This is the best site I come to for information and good discussions. I am typically one of the "silent" regulars on this forum, and I imagine there are many more like me. I would like to say a sincere thank you to John Cook, all the commenters (from all sides) and all contributors to this great site. While I find valuable information on other forums, such as RC, Open Mind, etc., this is the clearest and least hostile place I will first link to in discussions elsewhere.
  42. Astronomical cycles
    johnd, from NCDC data the linear trend from 1998 is positive. Same conclusion eyeballing the blue line in your graph. Only if you take the value of the single year 1998 and the single year 2009 you'll get a slightly decreasing temperature. Is this what you mean?
  43. Astronomical cycles
    Albatross at 02:38 AM, the trends are taken from the chart below. The question really is why did you choose 1986 when it appears the upward trend began about 1978?
  44. Astronomical cycles
    Johnd @22, I'm not sure what the point of your cursory analysis is. That sunspot number explains decadal trends in the global surface air temperature? Anyhow, I disagree with your assessment that (e). The OLS trend in the GISTEMP data between 1998 (~12 years) and now is +.134 K/decade, compared to +.09 K/decade between 1986 and 1998 (~12 years prior to 1998). Stats generated at woodfortrees.org. Why did you choose 1998?
  45. Is the long-term trend in CO2 caused by warming of the oceans?
    scaddenp: Challenge response: Pull back to 1850. According to most data, the temperature was pretty much flat at a value about 0.8C less than now. My model would show CO2 would stay constant. Linear Trend response: Add a linear trend to the Mauna Loa CO2 data, and the 0.58 term would change accordingly. Figure 2 would look the same, since the equation would subtract out the revised 0.58 value, and the shape of the Modified Mauna Loa data would be reproduced. Doug: I'm not sure what you mean by that, but if you are suggesting backing off the rhetoric, I all for it.
  46. Climategate CRU emails suggest conspiracy
    Obviously the whole point of the hacking was to look for dirt to publish. I'd love to know how many other people got hacked with nothing published, because there was no dirt to find. I know the answer might be "none", but equally, it could be hundreds.
  47. Andrew Bolt distorts again
    JB, not sure why you said 'nice try' regardless of whether this was directed at Canbanjo or Joe Blog. May I suggest that a lot of the controversy surrounding the IPCC reports could be (and could have been) avoided by having a formal IPCC questionaire to be completed by all of the contributors and reviewers following publication of the final report. This would then enable simple statistical analysis to determine eg percentage who endorse the core findings of the report. The survey refered to in post 12 is better than nothing but considering the damage the denialists are causing we need much better amunition (facts) to clearly highlight the consensus.
  48. Berényi Péter at 00:47 AM on 18 June 2010
    How climate skeptics mislead
    #189 skywatcher at 19:32 PM on 17 June, 2010 we've established there was no evidence for your hypothesis No, you have not. dealing with multiple lines of evidence, none of which may show you exactly what you want to know, but all of which point strongly to some overall conclusion Sounds like the prosecutor's job.
  49. Berényi Péter at 00:38 AM on 18 June 2010
    How climate skeptics mislead
    #185 e at 15:04 PM on 17 June, 2010 We are not born with this knowledge implanted in our minds, we have no choice but to construct that knowledge from our senses and our ability to apply logic. When that application of logic is used to derive general principles from given observations, that logic is by its very nature inductive, and thus can never give us a truly binary answer. Except it usually does not happen that way. What we actually do is to postulate universal principles very early in the process, based on little observational data. This step can be called inductive if you will, but it goes far beyond what is strictly necessary to explain the set of observations available at the moment. Ancient Greeks postulated circular motion for the Heavenly Bodies this way, because the Circle is the only perfect closed curve (whatever "perfect" means) and the behavior of the Heavens certainly looked like somewhat cyclic even at a first glance. The theory was extremely successful, had considerable predictive power, Ptolemaic cosmology has prevailed for one and a half millennia. As soon as the conceptual framework is given, we can happily rely on deductive reasoning using perfectly binary logic. Observation is still necessary to fine tune model to reality (you still need to determine the number, sizes, positions, orientations, orbits, periods of epicycles), but otherwise all you do is to calculate projections of these motions to the sphere of Heavens (which needs quite a bit of spherical geometry). Even its demise is enlightening. From retrospective analysis we know any quasi-periodic motion can be approximated by a sufficient number of epicycles with arbitrary precision. The proof goes something like the one for Fourier series. Therefore there was no way observation could falsify the theory provided of course the challenge was the accurate description of kinematic behavior of projections of Heavenly Lights to the Celestial Sphere. The model could be refined ad infinitum, with an ever increasing number of epicycles. Unfortunately during this process it became less and less understandable, and that was the real problem with it. With our vast computing power we could do even better on Ptolemaic calculations than medieval thinkers, there would be almost no limit to increasing the number of epicycles recursively. In reality came Nicolaus Copernicus and failed miserably. His model was much more transparent, than Ptolemy's (after all those epicycles added), but he was sill sticking to circular motion (this time around the Sun). Initially his theory was rejected not because of theological objections of the Catholic Church (those came later, preceded by early expression of distaste by Luther), but because it was all too easy to falsify it. Parallax predicted by his theory was unobservable and on top of that, with simple circular orbits its performance was much inferior to improved Ptolemaic predictions. One could of course add epicycles to planetary orbits around the Sun, but in that case what's the point of the whole exercise? Just to leave poor birdies behind in empty Air as Earth orbits the Sun? It was only after Johannes Kepler discovered elliptic orbits that the system got actually simpler. At least in a conceptual sense, if not computationally. By the way, the first two laws of Kepler were derived from a single case (Martian orbit), not from some induction on a wide sample of orbits. The pattern is the same even much later. Albert Einstein in developing his theory On the Electrodynamics of Moving Bodies didn't have to do inductive inferences on vast observational databases. He only used a single experiment (Michelson & Morley, 1887, not even citing them by their name, but just as unsuccessful attempts to discover any motion of the earth relatively to the ``light medium,'') and some symmetry properties of the Maxwell equations discovered earlier by Lorentz. Compared to this the inductive step he took was enormous. Ten years later he repeated the performance with his Geometrodynamics, this time only using the Eötvös experiment, geometrization of Electrodynamics by Minkowski along with some more symmetry speculations. I could go on with this ad nauseam from QM to String Theory. The general pattern is that very little empirical data is used for huge inductive leaps and most of the induction is done at rather high level by introducing some invariance principle, transforming the mathematical form of existing laws or even better, by finding mathematical structures that include the description of several unrelated fields as limit cases. The role of induction is more like a heuristic principle here, rather than a systematic tool working on many instances of observation. The bulk of work goes into derivation of specific cases from general equations obtained this easy and reckless way on the one hand and performing experiments to check these consequences on the other hand. Mathematics seems to play a central role in this process. Already Galileo has noted the great Book of Nature was somehow written in the language of Mathematics. It means even induction can be performed mainly on the symbolic level, as with quantization of certain representations in classical physics that are directly transformed to QM equations. Wigner's fifty years old essay, The Unreasonable Effectiveness of Mathematics in the Natural Sciences still ponders on this question. We can never be sure if these signs give us truth or not. However we have no choice but consider them true until proven false (by experiment or observation). With fuzzy truth-values assigned to propositions, even proper falsification becomes impossible. If something is 95% true, it may take quite a lot of counterexamples to get one convinced it must be false after all. Even then only a lower certainty might be claimed, 90% perhaps - still very likely. If even falsifiability is abandoned, we are left in the outer darkness. Binary logic is not for all. Spouses, not driven by logic, can perfectly well love and hate each other at the same time and one still have to deal with situations like this somehow. But right now we are not doing zen, we are doing science and in this fine tradition you should let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.
  50. Astronomical cycles
    Marcus at 21:18 PM, this chart perhaps helps with sunspot numbers. The relevant temperature trends are (a) A small temperature fall 1900 to 1906. (b) An extended temperature rise 1906 to 1940. (c) A steady or very slowly descending temperature period from 1940 to 1978. (d) An extended fairly rapid rise in temperatures from 1978 to 1998. (e) A short steady or slightly descending temperature period from 1998. http://www.ngdc.noaa.gov/stp/GEOMAG/image/aassn07.jpg

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