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Global warming and the unstoppable 1500 year cycle

Posted on 19 September 2010 by John Russell

For someone to state that the global warming we’re experiencing is actually part of a 1500-year natural cycle of global temperature variation is interesting for two reasons. First -- in contradiction to the great majority of skeptic arguments that actually deny global warming -- this argument requires that the person promoting this explanation must first agree that climate change is, indeed, happening.

Second, they must also refuse to accept the greenhouse effect, a theory first proposed more than 100 years ago and which even many skeptics of the human contribution to climate change, readily accept.

The 1500-year cycle in question has been observed mainly through ice core data as a warming in the northern hemisphere matched at precisely the same time by a cooling in the southern hemisphere. So it’s a heat distribution issue:  a global temperature ‘see-saw’ effect. The total heat in the global system remains constant.

In contrast, human-produced global warming has been caused by the rapidly increasing CO2 concentrations in the atmosphere over the last 200 years -- rising over 390 parts per million after remaining below 300 parts per million for the previous 800,000 years. And unlike natural heat variations, the current temperature increase caused by CO2 is being recorded occurring all around the globe – on the ground, in the air and in the oceans.

This post is the Basic version (written by John Russell) of the skeptic argument "It's a 1500 year cycle".

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Comments 1 to 33:

  1. Your discussion above is wrong on several points. Firstly and generally, you are grouping together and over-simplifying skeptical arguments in order to more easily label and discredit them. This is a common straw man technique. But to your first point, most skeptics don't deny that global warming is happening. They disagree about the causes, rate and relative degree. Instead of positing it as (almost) exclusively a human-caused effect, they tend to think that natural effects in the last several decades, as well as in the broader term going back centuries, have been understated. Secondly, (nearly all) skeptics do not reject the greenhouse effect. Once again, they disagree about the relative degree and rate. They do not generally disagree about the cause of the greenhouse effect either, ie gases produced by human activities cause a trapping of heat; once again they disagree about the relative degree this effect has as a causative factor to observed climate changes, and how much these climate changes are natural (or in some cases just weather). You are also wrong about the 1500 cycle being limited to the Northern Hemisphere. Voelker, Antje H.L. (2002). "Global distribution of centennial-scale records for Marine Isotope Stage (MIS) 3: a database". Quaternary Science Reviews 21: 1185–1212 "The pattern in the Southern Hemisphere is different, with slow warming and much smaller temperature fluctuations" I suspect you are only referring to the cycle within integlacial periods, where the effect is weaker. During ice age cycles, the cycle has been found in both hemispheres, although with less T variation in the Southern Hemisphere. The reason for apparent effects being limited during interglacials to the Northern Hemisphere is probably due to lack of data in the Southern Hemisphere, much the same as arguments once put forward for the Medieval Warm Period, which is more and more being conclusively shown to show up in the Southern Hemisphere, as more data is gathered. Your are also wrong in stating "And unlike natural heat variations the current temperature increase caused by CO2 is being recorded occurring all around the globe – on the ground, in the air and in the oceans. Natural T variations like ice ages occur all around the globe, so I don't know how you can state the above. This must be some kind of record for this site, at least 3 major mistakes in one discussion.
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  2. Thingadonta #1, Methinks you protest too much. Firstly, it is essential to group contrarians argument in bite-sized chunks so that they can be classified, even if that is not exact. Global warming is a single "inference to the best explanation" for a variety of phenomena. Contrarians try to refute some of the arguments while ignoring others, so that the collectivity of their efforts at refutation tend to be chaotic and contradictory. Contrarian Contradictions Secondly, the post does not say that most contrarians reject the greenhouse effect. Is said that SOME MUST DO SO in order to affirm a 1500 year climate cycle. Funny, your argument is actually what you are decrying - a strawman. About your third point, I will leave that for John.
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  3. "Skeptics" use bits of science like flack to deflect focus from their core arguments. In Thingadonta's case the core argument appears to be absent altogether. The core motive seems clear: impugn the credibility of the author.
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  4. I guess this is the problem with some basics versions , its to easy to pick apart becuase it is not detailed enough . Basic versions are just trying to outline an Idea and I think its hard not to generalise otherwise it would become longwinded and hard to give a quick rebuttal while standing on the train .
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  5. There's also the simple, it wasn't warming 1500 years ago answer too...
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  6. S. Fred Singer wrote the book on this subject but as we all know, Fred Singer is a lot like George Costanza.
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  7. Thingadonta: "Firstly and generally, you are grouping together and over-simplifying skeptical arguments in order to more easily label and discredit them. This is a common straw man technique." Yes, I agree with this and it annoys me to see it on this site. Although there are a lot of people who deny the warming, my understanding is that most skeptics believe there is a natural warming. Of course, that doesn't stop them from simultaneously saying that Arctic ice has recovered, or that warming stopped in 1998... "Secondly, (nearly all) skeptics do not reject the greenhouse effect. Once again, they disagree about the relative degree and rate." But they might as well reject it entirely, seeing as the end conclusion is that our CO2 emissions don't matter. The "to a relative degree" part of their argument comes across, to me, as just trying to appear more reasonable while still embracing their politically-motivated views on emissions cuts. "You are also wrong about the 1500 cycle being limited to the Northern Hemisphere." Unless I'm misinterpreting the text of the abstract, it seems to contradict what you say about it: "The spatial distribution of all records is biased towards the northern hemisphere, for the marine records especially towards the North Atlantic region. Terrestrial records cluster in western Europe, the western United States, and China." You even quote from the paper saying that the warming barely shows up in the Southern Hemisphere! However, I couldn't read the full paper so you may have something I missed. "Your are also wrong in stating "And unlike natural heat variations the current temperature increase caused by CO2 is being recorded occurring all around the globe – on the ground, in the air and in the oceans." "Natural heat variations" is an awfully vague statement and could refer to a lot of things, but it probably refers to the 1500-year heat variation being discussed here. Which, as I believe you have failed to demonstrate to the contrary, was mainly limited to the Northern Hemisphere. But yes, there are natural warming mechanisms that are global so may the text should be changed slightly. Greenman3610's video on YouTube does a good job at addressing this claim, in fact it may even do by itself instead of this text summary (no offense to John Russell though, he made a good effort):
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  8. I often see "skeptics" protest saying "hey, no one said the warming is not happening... we're just questioning its cause!" On the other hand, there are no-warming related arguments all around. It's Urban heat island effect, glaciers are not shrinking, Antarctica is gaining ice, the "hiding the decline" email and so on. I never saw a "skeptic" protest in one of those denier blogs and say "Come off it man! We know it's warming!" "Skeptics" are very flexible when they make their arguments.
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  9. "The 1500-year cycle in question ": In the discussion of Moberg 2005 in the MWP: Rhetoric vs Science thread, we saw hints of a long period cycle. The amplitude of that cycle appeared to be less than 0.3 degC; the current increase above that cycle is already 0.8 degC -- and climbing. The cycle is broken; thus the skeptic argument based on that cycle is also broken. So to counter broken hockey stick? Broken cycles!
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  10. @Tom: "You even quote from the paper saying that the warming barely shows up in the Southern Hemisphere! However, I couldn't read the full paper so you may have something I missed." I couldn't read that paper either, but I got curious and searched for thingadonta's quote ("The pattern in the Southern Hemisphere is different, with slow warming and much smaller temperature fluctuations") on Google. The first result to come up was this very thread (thanks, Google's fast indexing). The second was a Wikipedia article (last revision Sept. 8) on Dansgaard-Oeschger events: http://en.wikipedia.org/wiki/Dansgaard-Oeschger_event#Causes Voelker's paper is cited on that page. Note that D-O events occured during the last *glacial* period, which would render thingadonta's argument nil since we are now in an interglacial, so his example doesn't apply.
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  11. Answering #4, Daved Green- The problem here is not so much that being basic, it lacks detail, but rather, that the logical flow of the article is jerky and scattered, and the wording fatally imprecise. Under such circumstances, since, as #3 points out, "'Skeptics' use bits of science like flack to deflect focus from their core arguments", they latch on to each one of these shortcomings and do exactly that -- with gusto and great effect. As an example of the jerky flow, consider even the very first sentence. It announces that there are two things 'interesting'. Then it immediately lists them. But frankly, from that list, neither one sounds 'interesting'. So already the logical flow most plausibly promised by the opening sentence has been lost. But then the article switches to the 1500 year cycle itself. This switch is quite abrupt, since we STILL haven't seen anything 'interesting' in the "two things interesting". But here too, we fail to keep the logical flow: for the unfortunate phrase "global temperature see-saw effect" spoils the whole paragraph. How so? Because the phrase "global temperature" would most logically mean a -single- temperature, which in turn would most likely be an -average- temperature. But the 'see-saw' described must be rising temperature in one hemisphere, while the temperature falls in the other (and vice versa). At best, this would be an example of the rhetorical effect known as 'paraproskokian', since the expected meaning of the word turns out not to be ther right one. But as Wikipedia points out, paraprosdokiam "is frequently used for humorous or dramatic effect, sometimes producing an anticlimax" -- none of which fits here. (See http://en.wikipedia.org/wiki/Paraprosdokian). Frankly, if I wasn't already convinced of the basic truth of the AGW hypothesis, this article would not have convinced me either. It would not even have convinced me to research it further -- especially since it contains no references for its highly contentious claims. BTW: that final contentious conclusion is another example of fatal imprecision in wording: what is being "recorded all around the world" is NOT "the current temperature increase caused by CO2". What is being recorded is merely "the current temperature increase". How much of it is caused by CO2 is exactly the bone of contention (assuming that no one still doubts the accuracy of the measurement -- although you know that because of 'Climategate' they do doubt it). You only give skeptics excuses for disbelief when you misstate it that badly. Unsupported statements of the central thesis (here that CO2-caused temperature rise is already being recorded) belong in the proem, the statement or perhaps on the conclusion, but ONLY when the support has been provided in (the body of) the argument. But where IS it? It just isn't there. Without it, you have no rebuttal at all.
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  12. "Although there are a lot of people who deny the warming, my understanding is that most skeptics believe there is a natural warming." My impression actually is that most skeptics claim we are cooling, and have just entered a cooling phase that will go on for decades. "It's cooling" is #4 on the skepticalscience most used skeptic arguments and I think that's probably about right. What I see when I trawl google news for comments sections of climate related news articles is a lot of people throwing out the claim that the Earth has stopped warming and is now cooling. They cite Phil Jone's statement about 1995-, they cite a recent switch into a negative PDO. They cite certain russian scientists who predict the maunder minimum stuff.
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  13. The problem for Thingadonta’s arguments is that global warming is occurring as evidenced by its effects in both the Arctic and Antarctic. In the north there is empirical evidence of depletion of sea ice and melting of the Greenland ice cap. In the south there is melting of the West Antarctic ice sheet and retreat of glaciers, while in East Antarctica there is evidence of increasing ice loss at the fringes of the ice cap. Grace satellite measurements confirm that these changes are occurring and doing so at an increasing rate. Thingadonta seems to assert that since ice ages are a global phenomena, this disproves that CO2 induced global warming is now occurring. Frankly, I don’t understand that argument. The present problem with CO2 is that human activity is responsible for it increasing at rates vastly in excess of that which would otherwise occur. In decades we release into the atmosphere what would otherwise take hundreds of millennia to accumulate. Can that occur without causing the global warming which is now so clearly evident?
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  14. (#12)My impression actually is that most skeptics claim we are cooling, and have just entered a cooling phase that will go on for decades. Skeptics not only believe that the Earth is cooling; they also believe that the Earth is warming. They believe that the warming can be attributed to natural causes, and they believe that the warming is due to the urban heat-island effect. In addition, they believe that it's impossible to tell whether the Earth is warming or cooling because so many temperature stations are set up next to air-conditioners and bbq grills. They believe all of these things; that's how they make sure that they have all of their bases covered.
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  15. Here is a question to the skeptics: why don’t you provide a classification of the different climate theories held by climate skeptics ? People who don’t believe in global warming have entirely different convictions from those who do believe the earth is warming due to natural causes. In fact, these 2 points of view are as different as any skeptic theory is from the AGW theory. In order to advance the discussion, the classification “climate skeptic” is just not enough. F.i. the alternative theories could be named: NoGW, NatGW (with subclassifications: NatGW_solar, NatGW_ocean_currents, …), NonCatAGW (non-catastrophical AGW), etc. AGW is just one of the many possible climate theories – with an overwhelming amount of evidence on its side …
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  16. @Ann: you won't see this happening, because many "skeptics" change positions depending on the current argument. The goal is to keep an aura of confusion around the debate. Now, there is a small minority who holds steadfast views on AGW, but you don't often hear from them on Internet forums...
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  17. Addressing even the most bizarre myths put forward by "skeptics" is important, and IMO, does not amount to arguing a straw man as some are suggesting here. Only the other day I was reading a CBC forum on the Arctic ice and "skeptics" were parroting Singer. How he can claim to have any credibility (and even more astounding, how people can still buy into his "science") on climate science is truly bizarre.
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  18. @thingadonta: You've just commented on a website dedicated to countering with scientific evidence 121 largely disparate, mostly contradictory, and definitely not unified "arguments" placed against climate science ( http://www.skepticalscience.com/argument.php ) -- often made by the same people. The contrast between that situation and the one found in the present state of climate science that unifies wide-ranging physical phenomena and finds multiply converging lines of evidence is utterly striking. If there is any confusion concerning the state of "skeptical arguments", it's certainly not John Cook's fault.
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  19. thingdonta, Your words shine like "...a good deed in a naughty world." Merchant of Venice, (William Shakespeare). 1. OK, climate change is happening. 2. The atmosphere causes average temperatures to be ~33 Kelvin higher than without the atmosphere. Let's call that the "Greenhouse Effect". 3. CO2 has an effect on global temperatures but not enough to to explain the observed variations on any time scale. What thingdonta says is totally vindicated by the Vostok ice core records but just for light relief here is Richard Alley's lesser known ice core data going back only 50,000 years for central Greenland. This data set shows the recent "Hockey Stick" but also the warm period that allowed Vikings to colonize Greenland and the subsequent cold period that destroyed their mini-civilization: http://www.foresight.org/nanodot/?p=3553 For those who are inclined to doubt the Foresight Institute, you can make your own analysis by retrieving the raw data from NOAA: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
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    Moderator Response: #3 is covered in the post CO2 Is Not the Only Driver of Climate.That's where you should discuss it.
  20. GC - how many times have you brought this up here? How many times has it been explained to you that your conclusion is totally faulty (CO2 can be forcing and feedback and you cant make the maths come out any other way)? What is so hard about you understanding this?
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  21. Just noticed a small typo in the 3rd paragraph: 'rising over 390 ppm' should be 'rising to 390 ppm'.
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  22. From the article above: "The 1500-year cycle in question has been observed mainly through ice core data as a warming in the northern hemisphere matched at precisely the same time by a cooling in the southern hemisphere. So it’s a heat distribution issue: a global temperature ‘see-saw’ effect. The total heat in the global system remains constant." I'm sorry but this simply has not been shown. I have already refuted the idea in my comments in the relevant "Argument" # 21. (comments 7 & 8). It's time to wise up gentlemen. Climate science is not science.
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  23. Not been shown? This is just the summary basic version. Perhaps we need to wait and see how the intermediate and advanced versions of this one pan out then.
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  24. Re: daniel (22)
    "I'm sorry but this simply has not been shown. I have already refuted the idea in my comments in the relevant "Argument" # 21. (comments 7 & 8). It's time to wise up gentlemen. Climate science is not science."
    Dude, you're giving me a bad name. I've read your comments over at argument 21 (7&8). Merely asserting something could be wrong and alleging impropriety doesn't make it so. If you have something of substance that will stand peer review that supports your allegations - bring it on. Or better yet, publish it. I'm sure you'll find many "skeptical" organizations will be glad to provide you with technical copywriters to assist you as well as financial support for your time to do so. I also suggest you actually do a little research on the background of paleo temperature records. Here's just one place to start. There are many more. In the meantime, you're blurring the line between skepticism and denial. BTW, climate science IS science. Hence the use of the term "science". The Yooper
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  25. I guess I must respond without the hoopla... I'll try "Dude", you give yourself a bad name. You believe unshakeably in anthropogenic global warming without much desire for, or competence in, critiquing the "science" behind the fad. Please also see the enormous link in comment 222 on the "There is no consensus" comments page 5. You will read a little about the not particularly thorough, easily skewed towards 'group think', peer review process and then reconsider your lame appeals to authority when trying to play down my claims. I am allowed to criticise scientific literature daniel, that is how scientific thought is truly refined, after publication. So many crusaders in the name of science just don't understand this (or don't want to). The link you provided is not specific to ice core dating. Why do you simply believe in O/E events without asking the hard questions daniel. It's just not good enough for you to lie there in your warm blanket of ignorance and say it's up to me to provide what wasn't provided by the "experts" in the first place. "In the meantime, you're blurring the line between skepticism and denial." Nice one liner here's one I thought of for you "Give up, you're an amateur" What kind of error margin would you put on the assignment of years in an ice core daniel? Do climate scientists bother to do so? Why don't you ask John to augment the article with some of that real scientific analysis. You should be thanking me for putting these comments in before he blunders the "intermediate" version up as well. All the best The Danster
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  26. daniel #25: You should read up on the psychiatric concept of 'projection'.
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  27. daniel #25 You're sailing pretty close to going against this site's comments policy with that post. It's perfectly possible to make your argument without recourse to the use of inappropriately emotive terms such as "crusade", "lame", "bother to do so" and so on, and in fact will help your argument to be taken more seriously. I strongly suggest that if you want your comments to remain on this site, then you adapt to condtions that will prevent your posts from being deleted. By the way, it's not "appeal to authority", it's "appeal to inappropriate authority". Good examples of inappropriate authority are Christopher Monkton, Tony Abbott and Al Gore.
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  28. Seriously? daniel going off with comments like "give yourself a bad name", "without much desire for, or competence in, critiquing the 'science' behind the fad", "not particularly thorough", "skewed towards 'group think'", "lame appeals to authority", and so on does NOT get removed for violation of the comments policy... but me implying that he might be projecting DOES? Seriously? My claim that some of the things he was saying MIGHT apply to daniel himself was unacceptable, but him saying those things definitely do apply to people he disagrees with is ok? Obviously this post, in repeating the suggestion that he might be projecting, is every bit as 'much' a violation as the original one sentence version and thus may well be removed also... but it would be nice if there was some kind of logical consistency in application of the policy.
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  29. The Danster #25 wrote: "What kind of error margin would you put on the assignment of years in an ice core daniel?" Actually, proxy records are generally described in terms of 'resolution' rather than 'error margin'. For instance, ice core records are generally considered to be accurate on the scale of centuries. Some more recent forms of sediment analysis show data resolution at the decade scale. I'm not aware of any proxy which claims to be able to accurately distinguish each individual year. That said, some individual years CAN be picked out of many proxy records due to unique events... atmospheric atomic detonations, specific meteor impacts, and so forth. So yes, climate scientists actually DO have reasons for these things rather than 'just making up dates' as you seem to imply. I'd explain why I think you make this mistake, but apparently it isn't allowed.
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  30. Re: daniel (25) First, I must echo the thoughts expressed so ably by kdkd and CBDunkerson above. Your insistence on attempting to personalize a science discussion is telling. Frame your debate around the science, not vitriolic personal attacks and you will gain credibility here. This is not p_o_l_i_t_c_s, where (when lacking in position and substance) attacking the messenger is considered "fair game". No one (other than yourself, by running afoul of the comment policy) prohibits your offering up critiques of literature presented. When doing so, please offer up sourced support for your position, or be careful to delineate what constitutes fact vs opinion. Unsupported position reverts back to opinion when it contradicts the known science. My use of the term "dude" was an attempt to lighten the conversation. That's it. Nothing else implied. My attaching the appellation "Yooper" to my signature is due to another "Daniel Bailey" also commenting on science blogs. I use my real name. Others use whatever they feel like (my favorites are "Albatross" and "A_ray_in_Dilbert_space" - classics!). If I could think of a cool, unique signature tag I would use it. Yooper is the best I have; it denotes the geographic area in which I live (people from here are referred to as "Yoopers"; there is no bad connotation associated with it). While I did play sports in college, that period and lifestyle was a lifetime ago. What endures is the education and training I received: degrees in Earth Science, Cartography, Remote Sensing and History. I used those skills working for the Department of Defense for a long time; currently, I work in pharmaceuticals, making scientific articles and research digestible for the medical professional in the field. I try to "keep my hand in" in climate science by keeping up on the literature (10-20 hours of reading a week is what I spare). I share this not to brag, but to give you some idea of my background & credentials. I chose a reference at hand in my response to you to give you an example of where to get some background info; it wasn't meant to tell a whole picture. People commenting here are expected to educate themselves and to ask questions when they hit roadblocks. When offering up commentary, it's equally expected that positions running counter to the science be sourced with a reference. Equally, when replying to a comment running counter to the science, it's good form to offer up a source for the reader (not just you) can go for ancillary material. I, and most others here, have no wish for AGW to be the reality it is. Wishing it weren't so will not undo what has been done. Every day I search the comments here for a scientific basis to undo AGW. None has been offered. The radiative physics of greenhouse gases are well-understood and have endured the withering scrutiny of peer review in the scientific literature for generations. The rest of my comment stands. As an addenda, it would be illustrative to look up Confirmation Bias. The Yooper
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  31. Danster #29, you seem to be arguing that the resolution of proxy records is not sufficient to determine the timing of Dansgaard-Oeschger events sufficiently to rule out current warming being such an occurrence. Has it not occurred to you that this argument is inherently self-defeating? The very EXISTENCE of D/O events and the '1500 year cycle' is DERIVED from those proxy records. If the dating of the proxy temperature records were as inaccurate as you suggest then the D/O pattern could never have been identified in the first place. So, even if we were to accept the idea that scientists (on BOTH sides of the debate, since Singer is a big D/O proponent) have been involved in a massive conspiracy to produce a false proxy temperature record... that would remove all foundation for D/O events. Certainly not establish them as the cause of current warming.
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  32. @Daniel Bailey (#28): excellent response. I join the others here in asking the Danster to lower the rhetoric and stick to science. I myself have seen a (long) post deleted recently because I started to get personal with Baz. I did not complain about it because I recognize I went too far, even though Baz was being frustratingly obtuse (in my humble opinion). Those are the rules of this forum, and we all have to respect them.
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  33. Re: archiesteel (30) Thanks for the compliment. One thing I have learned from this (I try for a positive takeaway whenever possible) is that certain individuals come to forums such as this to...see what reaction they can stir up. Like a petulant child continuing to throw rocks at a bees nest when told repeatedly to stop. By emulating Gavin Schmidt or John Cook instead of Tamino (while fun, just isn't my style) I think I can be of better service to more questing here. And it won't feed into the rock-throwers. More On-Topic: If we now are experiencing record heat & thawing in the Arctic, shouldn't we be experiencing record cold and sea-ice & ice sheet advance & mass-gain in the Antarctic? Oh, that's right, sea ice diminishing there, too; net mass-losses in both the WAIS and the EAIS...guess this post by John Russell is spot-on. The Yooper
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