Graphic View:
"Hockey stick" plot of the variation in temperature, sometimes inferred from natural records such as tree rings (above), shows a 20th-century warming spike.
Image:
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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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The “hockey stick” graph has been both a linchpin and target in the climate change debate. As a plot of average Northern Hemisphere temperature from two millennia ago to the present, it stays relatively flat until the 20th century, when it rises up sharply, like the blade of an upturned hockey stick. Warming skeptics have long decried how the temperatures were inferred, but a new reconstruction of the past 600 years, using an entirely different method, finds similar results and may help remove lingering doubts.
The hockey stick came to life in 1998 thanks to the work of Michael Mann, now at Pennsylvania State University, and his colleagues (and many other climate scientists who subsequently refined the graph). Reconstructing historical temperatures is difficult: investigators must combine information from tree rings, coral drilling, pinecones, ice cores and other natural records and then convert them to temperatures at specific times and places in the past. Such proxies for temperature can be sparse or incomplete, both geographically and through time. Mann’s method used the overlap, where it exists, of recent proxy data and instrument data (such as from thermometers) to estimate relations between them. It calculates earlier temperatures using a mathematical extrapolation technique [see “Behind the Hockey Stick,” by David Appell, Insights; Scientific American, March 2005].
Martin Tingley of Harvard University calls his approach “much easier to handle and to propagate uncertainties”—that is, to calculate how the inherent limitations of the data affect the temperature calculated at any given time. The method can easily be modified to answer other questions in climate science, such as about precipitation and drought, and can even make projections into the future given rates of buildup of carbon dioxide in the atmosphere. Written with his thesis adviser Peter Huybers, his paper was submitted to the Journal of Climate.
Tingley and Huybers’s new method, which Mann describes as “promising,” makes the assumption that nearby proxies can be simply related, or “chained,” either to data from nearby places or to data from the same place taken a few years before or after. For example, temperatures at neighboring places as measured in the last century seem correlated in a way that drops off approximately exponentially, with a “half-distance” (akin to the concept of half-life) of about 4,000 kilometers.
Tingley assumes a simple, linear relation between the proxy data values and the true temperature. This relation is then determined from proxy data and (where they exist) instrument data, using a methodology known as Bayesian statistics. Huybers explains that with Bayesian descriptions, “we attempt to estimate how probable certain temperatures were in the past given the sets of observations available to us.”
The sheer amount of computation, however, is daunting, involving heavy matrix algebra. Initial values for proxies and temperatures (where they have a known overlap) are input, and the methodology works backward to refine the relations at other times. To determine past temperatures, Tingley typically had to manipulate about one million matrices, each consisting of 1,296 columns and 1,296 rows.
Focusing on the past 600 years of proxy data between 45 and 85 degrees north latitude, Tingley’s initial results, presented at a conference earlier this year, find that the 1990s were the warmest decade of the period and that 1995 was the warmest year. (The El Niño year 1998 was the warmest year for North America and Greenland but not for northern Eurasia.) He also found that the 20th century had the largest rate of warming of any century and that the 1600s had the largest rate of change overall (and larger than previous reconstructions), albeit in the cooling direction thanks to the so-called Little Ice Age.
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56 Comments
Add CommentPlease tell me this will finally put to rest the Yamal pseudo controversy.
Reply | Report Abuse | Link to thisIt is certainly refreshing to see a substantial refinement in the reconstruction of Earth's temperature history. but the graph in the magazine (p.22) doesn't seem consistent with claim in the text that the 1600s had the fastest change rate due to the cooling of the "mini ice age". The graph seems to show the dip as happening in the late 1400s. It's odd too that nobody seems willing to plot the temperature history in this century.
Reply | Report Abuse | Link to thisThe Tingley and Huybers article in question appears to be online in preprint form at http://www.people.fas.harvard.edu/~tingley/mean_variance.pdf .
Reply | Report Abuse | Link to thisA lively discussion has already started on Climate Audit, at http://www.climateaudit.org/?p=7502 .
For the benefit of those who do not follow CA regularly, there has been an on-going discussion of the Yamal series employed by T&H (series #8 in their Fig 3), as "crack-cocaine for climatologists", whence the lead U-Tube link.
Be sure to scroll down to Grace Slick's White Rabbit video!
The Authors did not address the Yamal controversy. They deepened it by using the controversial Yamal series. Let's be clear about the main issue with Yamal: a sample count that is too low for a methodology (RCS) that is documented ( by briffas co author Melvin) to:
Reply | Report Abuse | Link to thisA: create a hockey stick out of a sample with no signal
B: produce an upward bias in the modern period.
The Yamal series ( a chronology of ring width indices) was produced by a method (RCS) that demands a large sample with varied growth rates and tree ages to reduce certain known biases. The series in question uses too few trees ( less than 15) and does not use the recommended 2 cores per tree.
David --
Reply | Report Abuse | Link to thisThe print version of your article includes a graph of temperatures over the last 1000 years. However, the graph, which is not included here, is not identified in the print edition. Is this the new Tingley-Huybers reconstruction you are discussing, or just the original, disputed Mann et al (1998, 1999) Hockey Stick?
In either case, would it be possible to add it to this online version in order to make it a complete reflection of the print edition? (With proper identification, of course.)
Also, there are a several unpublished studies on Tingley's website. Are you discussing the one linked in my previous comment, or one of the others? If so, which one?
Your photograph illustrates some of the problem of using tree ring widths as an indicator of temperature. The rings on the right of the photo are quite wide, indicating very warm conditions by this metric. However, the same rings, if followed around to the bottom of the picture, become quite narrow, indicating much colder conditions for the same years! There may be a temperature signal in tree ring widths, but it is hard to differentiate from precipitation, CO2 fertilization, etc. Any temperature effect is likely non-linear, and may even be non-monotonic.
Series like Yamal with small calibration-period replication are doubly hard to correlate confidently with temperature. At a minimum, Yamal should be merged into the nearby Polar Urals series in order to bring the replication of both up to usable levels, as per the recent discussion on climateaudit.org.
The article is interesting, but what is missing is a link between warming and CO2, which is not much more than a statistical correlation. I also am not impressed by matrix calculations even though their sizes are as big as 1296x1296. Any computer handles them like a piece of cake, as I have myself experienced doing prediction analyses on telecommunications performance metrics. I had to multiply 400x400 matrices (transposing them, finding inverses, etc.) and used a hand-held HP50G, a far cry from a university computer. So much for "heavy matrix albegra", who is the writer trying to impress? What is also not discussed is the non-increasing temperatures of the last 12 or so years. Has the hockey stick stopped, perhaps? If so, why?
Reply | Report Abuse | Link to this"...but a new reconstruction of the past 600 years, using an entirely different method, finds similar results and may help remove lingering doubts."
Reply | Report Abuse | Link to thisI doubt this very much. It's hard to remove the doubts of those whose convictions have nothing to do with logic or evidence.
Actually, the doubts have to do with the absence of logic or evidence. When the proponents of warming expect us to destroy the economy to make changes based on evidence they refuse to provide for replication, that is a problem. I am not necessarily saying that warming is not happening, but so far, the scientific evidence, totally released for replication and review does not exist. In fact, every time it has been released, significant problems have been found with it.
Reply | Report Abuse | Link to thisThere is every reason to demand the best of peer and citizen review of climate change assertions and the policy intended to deal with the problem. Loose assertions of an "illogical" viewpoint ascribed to either side are not productive. Even accepting the notion that we are participating to an extent worthy of the moniker "anthropocene", the predictions of things like sea level rise differ widely depending on the data density and computer model assumptions. Weather predictions are a known example of chaos, climate models may face something of the same challenge.
Reply | Report Abuse | Link to thisI'm simply referring to the favorite practice deniers employ in their arguments, that is, dodge the science and numbers and levy political accusations against all opponents.
Reply | Report Abuse | Link to thisWhen the deniers are able to provide solid, peer reviewed evidence that is NOT a complete diatribe against the evil conspiracies which seek the downfall of our economy, maybe the rest of us will be more inclined to treat them as a legitimate voice.
If deniers want to be respected, they better start behaving in a manner which is worthy of that respect. As of now the only things that can be attributed to their cause are mud-slinging and smoke-blowing.
Since when is innovating alternative energy products, and working harder on overpopulation issues "expecting to destroy the economy"? dondad, can you cite evidence that shows all, or any significant number, of "proponents" of anthropogenic climate change expect us to destroy the economy? Exactly how is increasing efficiencies in production and consuming useful, recyclable items instead of consuming throwaway fuels and products supposed to destroy the economy? How is making homes and workplaces more comfortable and clean supposed to destroy the economy? How is replacing temporally limited resources with unlimited resources destroying the economy? How is spending more on quality materials instead of fuel supposed to be bad for producers? How is producing more and destroying less supposed to be bad for GNP?
Reply | Report Abuse | Link to thisHow can dondads expect people to listen to such diatribe? When a teacher, like me, doesn't understand a student because the student is smoke-blowing, they fail the student. That is my assessment of dondad's diatribe.
Well-put, galaxy-man. "Destroying the economy" is a straw man.
Blanket statements like that demonstrate how denialism flourishes. The IPCC is arguably the most extensive metaanalysis of any scientific literature in history. There is no essential disagreement on the fundamentals of climate change. Nor do decadal trends in temperature reflect anything but decadal trends in temperature. No one thinks that global warming can swamp natural Terran atmospheric cycles, such as hurricane intensity. However, since those cycles are due to atmospheric conditions, alteration of atmosphere through climate change will alter those cycles (hence why the last 10 years may not directly plot on predictions).
Reply | Report Abuse | Link to thisThe denialists use the classic, tried-and-true technique of obfusticating over minor details. But come on, we're talking about climates over hundreds to thousands of years. Climate research is so difficult that it gave birth to chaotics - that small variations are inherently unpredictable. Given that a hundred years after Einstein, we still don't understand gravity, which is comparatively angelically behaved, why are we really surprised that 20-30 years of much less intensive research hasn't provided clear-cut statements on how climates change?
Try approaching science as a human endeavour, and you might be pleasantly surprised by how hard people work to provide accurate information.
"The Authors did not address the Yamal controversy."
Reply | Report Abuse | Link to thisThe Yamal Controversy is a manufactured controversy. That McIntyre refuses to publish his findings in a relevant peer reviewed journal tells us more about the blog science that McIntyre practices than any problem found with Yamal.
"Let's be clear about the main issue with Yamal: a sample count that is too low for a methodology (RCS) that is documented ( by briffas co author Melvin) to:"
A: create a hockey stick out of a sample with no signal"
You did know that the Yamal data was never used in the original Mann studies of 97 and 98? No? I am not surprised.
"B: produce an upward bias in the modern period."
You did know that the "modern period" temperature record is constructed by using modern instruments like thermometers, no?
"The Yamal series ( a chronology of ring width indices) was produced by a method (RCS) that demands a large sample with varied growth rates and tree ages to reduce certain known biases. The series in question uses too few trees ( less than 15) and does not use the recommended 2 cores per tree."
We await the publication of these findings in the appropriate peer reviewed journals. Something tells me it will be a long wait.
It is difficult to provide peer reviewed evidence when the proponents refuse to release any of the data that they are using to "prove" their case. I could make up some evidence, get it peer reviewed by people that I know agree with me and then release my findings without any of the underlying data. This is exactly what the proponents are doing. It is a bit disingenuous to call it mud slinging and smoke blowing when that is exactly what the proponent side is doing. Science requires access by all to the data and let the chips fall where they may. It is rather telling that every time some part of the data comes to light, there seems to be a lot of problems with it from a scientific and statistical standpoint.
Reply | Report Abuse | Link to thisI have nothing against trying to recycle or reduce waste. I may not be as erudite as you. If you look at the data that is freely available as to the cost to move the co2 emission levels back to earlier levels, it is in the trillions of dollars. That, to me constitutes a significant drain on the economy. It might even be worth doing it, but I, for one, am not willing to do so based on the word of a few "scientists" that refuse to release the data that they are basing their reports on. In one of the instances, the "data" was somehow destroyed so it cannot be retrieved, but take their word for it. Based on you being a teacher, I am sure that if a student comes to you and says that the dog ate my homework, but you can take my word that I did it, you give them an A with no further ado. That is exactly what you are proposing for others.
Reply | Report Abuse | Link to thisJust tell them to release their data for anyone to replicate the results.
Reply | Report Abuse | Link to thisHow can climate alarmists state on one hand that we can't take one year or even one decade as a indicator of climate change because we're looking at the big picture of thousands of years and also maintain that if we dont cut carbon emissions next week to 1950's levels that the planet is doomed?
Reply | Report Abuse | Link to thisNo data release for replication by climate alarmists, draconian carbon cap and tax systems and government regulation, unreliable/unrealistic computer models, and the above mentioned inconsistancies are all reasons not to deny climate change but to atleast put the brakes on things like the upcoming Copenhagen summit treaty that promises more requirements that China and India will ignore and tie the hands of the economies of the signatories.
@Dondad,
Reply | Report Abuse | Link to this"It is difficult to provide peer reviewed evidence when the proponents refuse to release any of the data that they are using to "prove" their case."
Since Mr, McIntyre has admitted to having the data for the past five years that he claims to have demanded for the past decade I wonder what is keeping him?
http://www.climateaudit.org/?p=7310#comment-360284
"In response to your point that I wasn't "diligent enough" in pursuing the matter with the Russians, in fact, I already had a version of the data from the Russians, one that I'd had since 2004. What I didn't know until a couple of weeks ago was that this was the actual version that Briffa had used."
Wow. Just amazing he had the data for five years? What is the excuse now? Take a look at the data sets that are available from NOAA. When can I expect the stream of McIntyre papers on paleoclimate?
http://www.ncdc.noaa.gov/paleo/data.html
"I could make up some evidence, get it peer reviewed by people that I know agree with me and then release my findings without any of the underlying data."
Do you have evidence that your scenario is nothing more than casual calumny?
"It is a bit disingenuous to call it mud slinging and smoke blowing when that is exactly what the proponent side is doing."
Tu quoque. Any more logic suicide bombs you wish to explode?
" It is rather telling that every time some part of the data comes to light, there seems to be a lot of problems with it from a scientific and statistical standpoint."
You know what I think is telling? That these "problems" never get published in a relevant scientific journal but give all appearance to be the product of a disinformation campaign. You know like claiming that you can not get data that you have had for five years or that the data you claim to analyze is flawed and that when you get a larger sample size it also replicates the original data and all the other proxy data found all around the GLOBE. Now that is telling.
They may not be published in a journal, but the data, methodologies, and any other information is posted and available to anyone that wants to use it. Why don't you go through the data and prove all of it wrong, ie, peer review it. It doesn't have to be in a journal to be peer reviewed. I would submit, that in many cases, publishing on the web will get much more, and better peer review than the journals.
Reply | Report Abuse | Link to thisI looked at the link about the data. It would have been easy to go investigate and/or replicate the information if Briffa had bothered to confirm that the data was what he had used rather than stonewalling. That data was confirmed about three weeks ago. Perhaps you can do all you need in that time, but maybe others are a bit more thorough
Reply | Report Abuse | Link to this@dondad, "It is difficult to provide peer reviewed evidence when the proponents refuse to release any of the data that they are using to "prove" their case." Conspiracy theory is the refuge for those with no evidence and a chip on their shoulder.
Reply | Report Abuse | Link to thisFace it people, no amount of evidence is going to convince the deniers. The cure for paranoia is not more facts, it is anti-psychotic drugs...
It is amazing to me that even after our economy was trashed by mismanagement and a lack of oversight that the deniers want to deal with the current environmental crisis with mismanagement and no oversight. I guess freedom to some people means freedom to destroy everything as a result of their ignorance. No surprise that you find right wing fanatics behind this Laissez-faire self destruction. You can take the world just dont take my job&
"They may not be published in a journal, but the data, methodologies, and any other information is posted and available to anyone that wants to use it. Why don't you go through the data and prove all of it wrong, ie, peer review it."
Reply | Report Abuse | Link to thisHold it. We got one clown who makes unsubstantiated allegations about scientific misconduct and is demonstrated to have had the data he has been demanding for five years and you think it my job to debunk it? Lunacy.
Pro Tip: The burden of evidence rests upon the claimant. If you make allegations that fraud has been committed then it is your duty to provide the evidence.
"It doesn't have to be in a journal to be peer reviewed. I would submit, that in many cases, publishing on the web will get much more, and better peer review than the journals."
What a load of crazy. It has already been shown that McIntyre is slimier than a bucket of Eels and you think that all scientific research should just be what? Blogged? What next trial by Twitter?
What happens when the "science blogger" turns out to be a fraud and a shyster such a McIntyre? He does not get banned from publication, kicked out of his job, or even censured by relevant scientific organizations. He just keeps on blogging: is that not the case as it exist now?
How do you decide the allocation of funding for research? Do NASA instruments get placed in the hands of the unknown and unproven?
"I looked at the link about the data. It would have been easy to go investigate and/or replicate the information if Briffa had bothered to confirm that the data was what he had used rather than stonewalling."
Reply | Report Abuse | Link to thisWhat stonewalling? McIntyre had the data in his hot little hands for FIVE YEARS. How can you stonewall something that is already in possession of the Auditor? Does the Auditor not, dare I say, know the content of his own hard drive? Sheesh.
What is even more exasperating is that you clowns seem blithely ignorant of the half-dozen studies that have in the past ten years also show the Hockey Stick. Why do you Bozos think that if you ignore those studies it, it will go away?
Many, many paleoclimatic data sets exist and are on the Internet yet we just see no use of them by the pseduoskeptics. Why? Because in reality it was never about the data but the appearance of manufacturing controversy.
@Robert,
Reply | Report Abuse | Link to thisFace it people, no amount of evidence is going to convince the deniers. The cure for paranoia is not more facts, it is anti-psychotic drugs..."
Classic. Thanks for the smile.
Well I was going to aim my own little kick at dondad's sandcastle, but Trent1492 and Robert have done such a superb job that there's nothing left to say.
Reply | Report Abuse | Link to thisExcept thanks.
Hoo hah! Like a NASA fellow said recently about mission planning and evaluation, "well usually we all just get in a room and shout at each other". Some of the recent traffic aside, it seems that a few of us here might be willing to help me out on a few questions I have as a scientist and citizen on this topic.
Reply | Report Abuse | Link to thisSo,
1. Can anyone cite a comprehensive review of the "temperature proxies" that are the basis for these reconstructions? It should have been identified by the author of this piece. Should it not yet exist we shall all be stuck with some measure of uncertainty about the calibration of these tools.
2. What is the total volume of water in the oceans? How does it compare to the total volume of the Greenland and Antarctic ice caps? I suspect that just melting those ice caps to water at present temperatures will not drive up the sea level very much. Sea level rise must also come from the thermal expansion of warmer oceans, not just the added water as seems so often implied in popular accounts. Again our author might have developed this simple illustration or found some citations to it.
3. In Phil.Trans.R.Soc A(2008)366, p.4647, Reto Knutti surveys 22 climate models which in aggregate all perform better is reproducing data to date, but "despite the model improvements in simulating the present-day climatology, the model spread for the projected warming has not substantially decreased in recent years". What level of confidence is adequate to guide policy or mitigation technology? Isn't it possible that some level of irreducible chaos is afoot here?
Hello Reterry,
Reply | Report Abuse | Link to this"Can anyone cite a comprehensive review of the "temperature proxies" that are the basis for these reconstructions? It should have been identified by the author of this piece. Should it not yet exist we shall all be stuck with some measure of uncertainty about the calibration of these tools."
Such a review does exist. Well, I should say it exist up to 2005. The Intergovermental Panel on Climate Change published that review in 2007. It can be found in Working Group I (WG I), Chapter 6, pages 466-483.
"What is the total volume of water in the oceans?"
Volume of Earth's Oceans
http://hypertextbook.com/facts/2001/SyedQadri.shtml
1.37 *10^9 km^3
" How does it compare to the total volume of the Greenland and Antarctic ice caps?"
NASA's Earth Observatory publication on the Cryosphere gives the following figures:
Ice Volume Equivalent Sea Rise Meters
10^6 km^3
E. Antarctica 9.9 64.8
W. Antarctica 2.3 3.4
Greenland 1.7 7.6
Total Sea Level Rise: 75.8 Meters
Reference: http://eospso.gsfc.nasa.gov/science_plan/Ch6.pdf Page 265 PDF Download
"I suspect that just melting those ice caps to water at present temperatures will not drive up the sea level very much."
Geology says other wise.
"Sea level rise must also come from the thermal expansion of warmer oceans, not just the added water as seems so often implied in popular accounts."
That is true, and matter of fact, the IPCC in 2007 looked at those figures for thermal expansion. For a good analysis of this issue please go to :
The IPCC Sea Level Numbers
http://www.realclimate.org/index.php/archives/2007/03/the-ipcc-sea-level-numbers/
In the print edition, the News Scan item, Still Hotter Than Ever by David Appell in the November 2009 issue is problematic. Dr. Appells report praises what he says is an important new method of analysis, based on a paper by Tingley and Huybers (only submitted , but posted on the internet), which we must assume he has obtained, read, and understood. Not the least of the problems is the Hockey Stick graph he shows, which is apparently that of Michael Mann et al, the infamous MBH98 result. A good hockey stick, if one wants to be maximally alarming, should be relatively straight (the stick) and then relentlessly rising (the blade) in the 20th century The chosen graph has these features.
Reply | Report Abuse | Link to thisThe problem with the graph is that it is 10 years old and is highly controversial. Both the statistics used (unconventional PCA) and the data selection (including bristlecone pines) have been questioned by Steve McIntyre and Ross McKitrick (and others, including a Congressional panel in 2006). It also fails to show a historically agreed upon Medieval Warm Period (MWP). Given its infamous reputation (deserved or not), it is an unwise choice as a general illustration.
Somewhat more to the point, why didnt Appell choose a graph from Tingley and Huybers; the new results he is praising? Or at least something more recent, such as a revised Mann et al in 2008? Possibly because these new graphs would show some rediscovery of a MWP approaching todays temperatures (a bent stick), and worse, the fact that for the last 10 years, the warming has stopped (a bent over blade), neither of which is sufficiently alarming, if one is agenda-pushing rather than reporting on science, and both are contrary to being still hotter than ever .
The readers of Scientific American deserve to be treated with more respect.
Bernie Hutchins
Ithaca, New York
I think the "hockey-stick" analogy has to do with the angle of the stick rising up from the blade which is flat on the ice, not an up-turned hockey stick blade.
Reply | Report Abuse | Link to thisdondad clearly has no idea what the concept of "peer-reviewed" means.
Reply | Report Abuse | Link to this@Bernie,
Reply | Report Abuse | Link to this"Not the least of the problems is the Hockey Stick graph he shows, which is apparently that of Michael Mann et al, the infamous MBH98 result."
I have already mentioned this a few post down but I think it is worth repeating that the Hockey Stick result has been replicated again and again. In other words the Hockey Stick is a product of reality.
"The problem with the graph is that it is 10 years old and is highly controversial. Both the statistics used (unconventional PCA) and the data selection (including bristlecone pines) have been questioned by Steve McIntyre and Ross McKitrick (and others, including a Congressional panel in 2006)."
You never read the original paper did you? I ask because if you had, you would know that not only tree rings are used but also ice cores, corals, ice accumulation and the instrument record. Why is it that you seem utterly ignorant of these other proxies and the fact that they all largely agree with each other?
Why is it that you neglect to mention that at the request of the Proceedings of the National Academy of Science expressed confidence in the fact that the present warming period is the warmest in four hundred years?
"Or at least something more recent, such as a revised Mann et al in 2008?"
You do realize that Mann 2008 substantiates what was said in 1998?
" and worse, the fact that for the last 10 years, the warming has stopped (a bent over blade), neither of which is sufficiently alarming,..."
You do realize that the past twelve years have been the hottest on the instrument record? No? Here allow me to help. NASA says the following:
"The ten warmest years all occur within the 12-year period 1997-2008. "
http://data.giss.nasa.gov/gistemp/2008/
if one is agenda-pushing rather than reporting on science, and both are contrary to being still hotter than ever .
Replying to Trent 1492
Reply | Report Abuse | Link to thisActually, you are wrong. I have read the MBH papers, and many many others. Further I have done the phony PCA with red noise, and out comes a hockey stick - no real data. Just mathematically generated 1/f noise. Have you tried this? If you also "prime the pump" with even one hockey stick, it jumps out faster - even faster than you jump to the wrong conclusions!
But I also said (and you ignored): Given its infamous reputation (deserved or not), it is an unwise choice as a general illustration. Sort of the bull and the red flag. Dont you agree? In particular, why not a graph from Tingley and Huybers? Appell was praising their new results, and shows 10-year old results. An ice-cream company with an exciting new flavor does not provide vanilla as samples. Does this not bother you - just a little?
I am not doubting the 20th century warming. Some sort of a blade is there from 1970-1998. The point I clearly made is that if we see a MWP (say 1000 years ago), nearly as warm or warmer than today, and if we also see a rise in the last 40 years that has leveled off for the last 10 (I never said cooled - yet), then we are far less alarmed than seeing a true hockey stick. This is a matter or establishing perspective honestly. Thats a good thing to do I hope you would agree.
@Bernie,
Reply | Report Abuse | Link to thisWhy is it you claim to have read the paper but you seem to just be rattling off Climate Audit talking points?
" Further I have done the phony PCA with red noise, and out comes a hockey stick - no real data."
When can we see your peer reviewed published results then?
"Have you tried this? If you also "prime the pump" with even one hockey stick, it jumps out faster - even faster than you jump to the wrong conclusions!"
You are not making any sense? Are you insinuating that all of the other subsequent studies are not in fact independent? What is your evidence for this? You seem to be seeing a Michael Mann behind every reconstruction. Did it ever enter your head the reason why you keep on getting the hockey stick is because this is what the analysis yields?
"But I also said (and you ignored): Given its infamous reputation (deserved or not), it is an unwise choice as a general illustration. Sort of the bull and the red flag. "
Shorter Bernie: My emotional responses should dictate the editorial policies of Scientific American.
"Dont you agree?"
No, Bernie I am an adult, I can handle bad news without stomping the ground and demanding that it not be published.
"Appell was praising their new results, and shows 10-year old results."
Which part of 'the results have been repeatedly replicated over the past ten years' do you not understand?
"Some sort of a blade is there from 1970-1998. The point I clearly made is that if we see a MWP (say 1000 years ago), nearly as warm or warmer than today,..."
You are just going to ignore those inconvenient studies that substantiate Mann, 1998 and hope no one notices, eh?
"...and if we also see a rise in the last 40 years that has leveled off for the last 10 (I never said cooled - yet), then we are far less alarmed than seeing a true hockey stick."
We have not seen a leveling off, Berine. That you ignore the NASA link noting that the past twelve years have seen the ten hottest years on the instrument record does not mean it does not sit there still just below your post.
That you think that a trend can be discerned concerning global climate by looking at just the past ten years is telling.
I
Replying to trent1492
Reply | Report Abuse | Link to thisLet me give you a VERY simple model to consider. I don't for a moment claim it is real, but it does illustrate an important point. I hope this simple point does not exceed your capacity. Then you can have the last word.
Suppose that the earths temperature is really approximately periodic (likely this is true - but just assume it), perhaps approximately sinusoidal, with a period of 1000 years, and that peaks occur around the year 1000 and around the year 2000. One of these peaks will necessarily be larger than the other. Lets assume it is the one at the year 2000, and that the variation is 10% larger than the one at 1000. The peak will likely be substantially flat for several years around 2000 (like the top of a sinewave). It is then necessarily true that for several years around the year 2000, the temperatures will be higher than at any time in the past 1800 years, and there is NOTHING remotely unusual, let alone alarming about this.
I will take 500 points for deflection, Alex. All those posts are just going to be conveniently forgotten, eh?
Reply | Report Abuse | Link to this"Suppose that the earths temperature is really approximately periodic (likely this is true - but just assume it), perhaps approximately sinusoidal, with a period of 1000 years, and that peaks occur around the year 1000 and around the year 2000.
Today's keyword is: Mechanism. Got a mechanism for this hypothesis? You know that solar and orbital mechanisms have been thoroughly ruled out?
One of these peaks will necessarily be larger than the other. "Lets assume it is the one at the year 2000, and that the variation is 10% larger than the one at 1000. The peak will likely be substantially flat for several years around 2000 (like the top of a sinewave). It is then necessarily true that for several years around the year 2000, the temperatures will be higher than at any time in the past 1800 years, and there is NOTHING remotely unusual, let alone alarming about this."
Will everyone please note that Bernie has gone from pure speculation to asserting a fact without even so much as a Texas stop in reality.
Several hallmarks place "man made global warming" into the realm of "Voodoo Science". The first is that experiments show contradictory results and that these results are glossed over. The example of this is the missing tropospheric hotspot. Occam's razor then raises the question: "Is it most simple to say that the hotspot is really there and therefore consistent with the computer models, but we are unable to measure it? Or is it simpler to say the computer models are flawed?" I know that True Belivers really, really, want to believe that that the tropospheric hotspot is there, but it isn't. So that gives me a cause for pause.
Reply | Report Abuse | Link to thisThe second hall mark is that data are witheld. The best recent example of that was the Cold Fusion fiasco. Despite many attempts by other researchers to replicate results, Pons and Fleischmann still insisted that thee experiments were being done incorrectly, but refused to provide the proper instruction to other scientists on how to re-create their results. This is the crux of the issue wit the broken Hockey stick. Data were withheld so long that it became a joke, and only through "advanced statistical analyses" can a pattern be recognized. The one question that needs to be answered is are there other "advanced statistical analyses" that can be done that show no hockey stick? Or did the researcher halt his research when he got the answer he wanted? I'm not impugning his or her integrity, but I've done enough modeling to know the human temptation is to stop when you get the answer that you're looking for, but that science demands that we proceed to try to poke holes in our own analyses before someone else does.
A third hallmark of "Voodoo Science" is that it violates the laws of physics. In this case it is well established that a doubling of CO2 in the atmosphere from 380 ppm to 760 ppm will produce a miniscule amount of additional heat trapping. This well established physical phenomenon is not in question. Taken in isolation, this would disinclude CO2 from causing anything other than an insignificant amount of atmospheric heating. True Believers, however have invented the concept of "forcing" by water vapour to amplify this small amount of heating into a massive problem. However, an experimentally testable example this concept of "forcing" has never been found in the real world; it only exists in the black box of computer algorthms and programs; which again, researchers are unwilling to release for examination.
Based on the above; I remain skeptical wrt to man made global warming.
skbarry:
Reply | Report Abuse | Link to thisPeer review prior to publication means that the paper has been reviewed for glaring errors. It relies on an "honor" system that the researchers have conducted their experiments properly treated their data correctly. However this system is open to abuse. As Robert Park pointed out in his book "Voodoo Science", Nature published an article in 1988 regarding homeopathy. Despite the editor having grave reservations, he felt that it was his duty to open up the area for discussion and later the article was thoroughly discredited. Unfortunately, the article's author, still claimed victory as he bragged about having an article published in Nature, so homeopathy must be correct, why else would it have been published in Nature?
So the conclusions that need to be kept in mind regarding peer review are:
1. It is merely a process by which data can be brought out into the larger scientific community.
2. It does not mean that the reviewers have examined and will vouch for every detail of the experimental results or interpretations.
3. It doesn't mean it's automatically true. It is very possible for garbage to be published, even in prestigous journals, as long as the editor has some other interest in bringing the topic to public discussion.
So Trent1492, before you go apoplectic on the above comments, they apply to both sides of the CO2 as Global Warming Cause debate. Please note that I refuse to use the term "Climate Change" as that is unscientific. CO2 as Global Warming Cause is what we are really talking about here, even though it doesn't roll off the tongue as sweetly and is less much less scary and marketable.
I encourage others in the debate to begin calling it what it is really is "CO2 as Global Warming Cause" .
2Shoshin,
Reply | Report Abuse | Link to this" Trent1492, before you go apoplectic on the above comments, they apply to both sides of the CO2 as Global Warming Cause debate. Please note that I refuse to use the term "Climate Change" as that is unscientific."
Why is it unscientific? You proclamations hold no weight with me.
"CO2 as Global Warming Cause is what we are really talking about here, even though it doesn't roll off the tongue as sweetly and is less much less scary and marketable."
You really should investigate what the term climate change means before pontificating about it. A warmer globe is only one aspect of the term. It also includes the affects such as changing rain patterns, rising sea levels, etc.
"I encourage others in the debate to begin calling it what it is really is "CO2 as Global Warming Cause" .
Will Don Quixote be accompanying you on this quest to change the scientific nomenclature. ?
"Several hallmarks place "man made global warming" into the realm of "Voodoo Science". The first is that experiments show contradictory results and that these results are glossed over."
Reply | Report Abuse | Link to thisWho dose that glossing? The world's geophysicists? Evidence?
http://www.atmosphere.mpg.de/enid/20c.html
"The example of this is the missing tropospheric hotspot."
Let us walk this one through. If humans are increasing the CO2 levels in the atmosphere then that means that more heat will be trapped in the lower atmosphere and the stratosphere will cool because more heat is being trapped. This is a prediction made and observed.
Stratospheric Cooling
http://www.atmosphere.mpg.de/enid/20c.html
Care to explain this phenomena without the input of humans? We know how much humans added to the global CO2 levels by isotopic analysis. Care to explain why an increase in a heat trapping gas will fail to trap heat?
"Or is it simpler to say the computer models are flawed?" I know that True Belivers really, really, want to believe that that the tropospheric hotspot is there, but it isn't. So that gives me a cause for pause."
You do know that these are real world OBSERVATIONS?
"The second hall mark is that data are witheld. The best recent example of that was the Cold Fusion fiasco. Despite many attempts by other researchers to replicate results, Pons and Fleischmann still insisted that thee experiments were being done incorrectly, but refused to provide the proper instruction to other scientists on how to re-create their results."
This is an example of science gone bad, how? Can you please provide evidence that the physics community accepted those results uncritically?
"This is the crux of the issue wit the broken Hockey stick."
It is broken because Shosin says it is broken. Nice try at assuming your premise. Classy that one is.
Of course you and all the others pseduoskeptics have ever answered this question: Which Hockey Stick? I like how you guys are just blissfully unaware of the repeated replication of the results.
"The one question that needs to be answered is are there other "advanced statistical analyses" that can be done that show no hockey stick? Or did the researcher halt his research when he got the answer he wanted? "
I am just wanting one question answered: Which one?
"Or did the researcher halt his research when he got the answer he wanted? I'm not impugning his or her integrity,..."
Which one? Care to explain why you are talking in the singular?
Trent1492:
Reply | Report Abuse | Link to thisRe: Your comments Stratospheric cooling: I looked at your reference. Your attempt to misrepresent the findings of that reference demonstrate only a dogmatic disregard for other's work.
The authors mention several other potential causes, and couch their words and findings carefully. As well, they cite a computer simulation that has no evidentiary standing whjatsoever.
You take what they say and twist it to satisfy your own agenda. You are no scientist.
There are no data to support your assertion. Again, please post some data.
@Shoshin,
Reply | Report Abuse | Link to this"A third hallmark of "Voodoo Science" is that it violates the laws of physics. In this case it is well established that a doubling of CO2 in the atmosphere from 380 ppm to 760 ppm will produce a miniscule amount of additional heat trapping. "
Climate sensitivity figures are based on the doubling of CO2 levels from the year 1750, which is estimated at 280 ppm. So we are talking about what the temps will be if the CO2 levels reach 560 ppm
And what is the consensus for climate sensitivity? Well let us go to the horse's mouth and ask. From the IPCC Summary for Policy Makers we find the following:
"It is likely to be in the range 2 to 4.5°C with a best estimate of about 3°C,and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but
agreement of models with observations is not as good for those values. Water vapour changes represent the
largest feedback affecting climate sensitivity and are now better understood than in the TAR. "
http://74.125.155.132/search?q=cache:mP2Kar2WNcwJ:hosted.ap.org/specials/interactives/_documents/climate_report.pdf+ipcc+2007+climate+sensitivity&cd=2&hl=en&ct=clnk&gl=us&client=firefox-a
So much for a minuscule amount.
"True Believers, however have invented the concept of "forcing" by water vapour to amplify this small amount of heating into a massive problem."
You had better go and tell the entire physics community about the "invented the concept of "forcing". Along with the invented concept of "radiative Equilibrium".
@Shoshin,
Reply | Report Abuse | Link to this"Re: Your comments Stratospheric cooling: I looked at your reference. Your attempt to misrepresent the findings of that reference demonstrate only a dogmatic disregard for other's work. "
Where is it misrepresented? Funny you will not quote from the article, eh?
FTA:
"Cooling of the stratosphere isn't just the result of ozone destruction but is also caused by the release of carbon dioxide in the troposphere. Therefore, global warming in the troposphere and stratospheric cooling due to ozone loss are parallel effects. As cooling increases, development of the ozone layer can be affected because a cold stratosphere is necessary for ozone depletion."
You did know that Ozone Depletion is anthropogenic? Did you miss the part where it says, "...but is also caused by the release of carbon dioxide in the troposphere."?
Let me go on: FTA
"So releasing more carbon dioxide may not only increase global warming but may also contribute to the formation of the ozone hole."
Wow, that is two for one, home goal by Shoshin.
Again, FTA:
"Why does the stratosphere cool?
There are several reasons why the stratosphere is cooling. The two best understood are:
1) depletion of stratospheric ozone
2) increase in atmospheric carbon dioxide."
Both of these phenomena are anthropogenic.
FTA:
Conclusions
"We now know that stratospheric cooling and tropospheric warming are intimately connected and that carbon dioxide plays a part in both processes. At present, however, our understanding of stratospheric cooling is not complete and further research has to be done. We do, however, already know that observed and predicted cooling in the stratosphere makes the formation of an Arctic ozone hole more likely. "
Reading Comprehension: It matters.
Why don't you ever see the data from Lake Vostok Ice core? Because it show anthropogenic climate change is none-sense. What a waste of time this hockey stick is.
Reply | Report Abuse | Link to this"What a waste of time this hockey stick is."
Reply | Report Abuse | Link to thisLike I keep asking and never get a answer too is: Which one?
http://www.pnas.org/content/105/36/13252/F3.large.jpg
People who wish to hear science writer David Appell in a Portland-based radio debate with climatologist Tim Ball can listen to the audio, which is available at
Reply | Report Abuse | Link to thisGoogle:
"Rare global warming debate: Skeptic climatologist Dr. Tim Ball vs. alarmist science journalist David Appell"
Or use this URL:
http://algorelied.com/?p=3044
It's a four-part audio recording.
Objectively speaking, Appell does not do very well. His apologists will be quick to point out that the talk show hostess, Victoria Taft, was against him. Likely she is acclimated to guests who are more politician than scientist, and clearly she is highly skilled in her job: such things as insisting that guests answer questions rather than attempt to wedge in all their prepared lines.
But Appell's main problem here is that he is at least 10 times less knowledgeable than Ball, and something like 3 times less articulate.
But Appell had his chances - he just couldn't DO anything with them.
His "fans" will be hard pressed to praise his effort here.
"Objectively speaking,..."
Reply | Report Abuse | Link to thisAfter reading this thread how could anyone consider you objective?
You are nothing if not dogged!
Reply | Report Abuse | Link to thisYou read my post and commented on it in just 34 minutes. That’s less time than it takes to actually listen to the audio files.
Can we just encourage readers to listen to the audio and make up their own minds?
"You read my post and commented on it in just 34 minutes. Thats less time than it takes to actually listen to the audio files. "
Reply | Report Abuse | Link to thisWhere did I claim that? Here is what I said, "After reading this thread how could anyone consider you objective?"
"Can we just encourage readers to listen to the audio and make up their own minds?"
I think you greatly exaggerate my powers.
Now that you HAVE had time to listen to the audio - what did you think of it?
Reply | Report Abuse | Link to thisJust Google:
appell ball debate global warming
Last word is yours.
Bernie Hutchins:
Reply | Report Abuse | Link to thisI know I should know better, but I also make the mistake of trying to talk sense to Trent1492. He is a political dogmatic with no sense of science or reality beyond his narrow ideological view of the world. Best let him spin in the wind.
Of course it confirms the "curve", would it have been printed otherwise? Henri Suyd makes an excellent point about the handling of large matrices; basically, it comes to this, they are too big to trust the computed results!
Reply | Report Abuse | Link to thisInteresting posts - at least some of them. I read this article and noticed a few discrepancies - some of which have been pointed out by others.
Reply | Report Abuse | Link to thisFirstly, the study is over the past 600 years which coincides closely with the begining of the Little Ice Age - an example of allowing the parameters to verify the hypothesis?
Then there is the reference from Michael Mann whose original study was discredited not only by the statisticians mentioned earlier, but also (albiet in more mild terms) by the National Academy of Sciences.
Then there is the already noted fact that a 1000 year graph is shown for an article about a 600 year study, conviently erasing the Medieval Warming Period.
Lastly, and this is just an observation, I note that the jump in measurements from thermometers is far higher than the more modest jump recorded from tree rings, corals, ice cores and historical records. Could this be related to a preponderence of measuments occurring near population centers? (which not only generate more records but also are known heat sinks).
Regardless, this article calls into question, in my mind, the integrity of Scientific American (which I have been reading for over 20 years). I also think that regardless of the scientific evidence for or against "Anthropogenic Global Warming", it's not really about climate change - it's about money and control. As usual, follow the money...
"Firstly, the study is over the past 600 years which coincides closely with the begining of the Little Ice Age - an example of allowing the parameters to verify the hypothesis?"
Reply | Report Abuse | Link to thisHere is a novel idea. How about you provide evidence for this speculation.
"Then there is the reference from Michael Mann whose original study was discredited not only by the statisticians mentioned earlier, but also (albiet in more mild terms) by the National Academy of Sciences. "
So my question for you is: are you a dupe or a liar? I ask because when I go the cited report I find the following:
"The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and proxy sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.
Pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprec-
edented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically. iverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward."
Pages 3-4
http://www.nap.edu/catalog.php?record_id=11676
"Could this be related to a preponderence of measuments occurring near population centers? (which not only generate more records but also are known heat sinks)."
So you think that explanation for the sea warming is that the ocean floor is populated with a bunch of Atlantises. Fascinating. Here is major clue for you: Go to Google Scholar and put in Urban Heat Island. See all that literature on it? Now care to show how it is not accounted for in the literature?
"Regardless, this article calls into question, in my mind, the integrity of Scientific American (which I have been reading for over 20 years). I also think that regardless of the scientific evidence for or against "Anthropogenic Global Warming", it's not really about climate change - it's about money and control. As usual, follow the money..."
This message brought to you by: Exxon-Mobil.
What, Scientific American, the science journal of MSM record is silent on the current climate change scandal specifically concerning fraudster Michael Mann, the hero of this article?
Reply | Report Abuse | Link to thisNot surprising. When you spend so much time pushing ideology over science it is kind of embarrassing to admit that your research is so one sided and predetermined that foolish is an understatement.
This magazine is a joke. One of the reasons I stopped buying it years ago. You can't have a taint in one section without it staining the rest of the publication.
"What, Scientific American, the science journal of MSM record is silent on the current climate change scandal specifically concerning fraudster Michael Mann, the hero of this article?"
Reply | Report Abuse | Link to thisA. It has covered this manufactured controversy about the stolen E-mail's.
B. You are guilty of thinking that a baseless assertion is the same as evidence. News Flash: it is not.
Reply | Report Abuse | Link to thisThe Hockey-Stick
I wish to add a few tidbits from my research in writing the text:
“ The End of The Last Ice Age. “
No paper I have witnessed discusses the climate servos which began working at about 10,000 yBP to present. Yes, they are imperfect and do not hold temperatures to +/- 0.05 º C. I must refer to Chapter 3. titled: “ A Matter of Warmth “ in the noted text and section: “ Earth's Climate Control System, “ wherein I discuss the initial turn-on transient of a servo mechanism, the overshoot relative to what would eventually be a stable state, and the decremented oscillations that follow the turn-on. I predict without mathematical injection that the oscillations will continue for about 15,000 years and settle to about 35.1 º C at the Greenland NGRIP ice core research site. This as a natural state with no external interference. ( Not likely! )
It is my belief that all climate researchers should investigate the effects of servos on their projections and examine my Ill 7.6, 7.7 and 14.00. to better define their data on paleoclimate. Keep in mind: “ The past is prolog for the future and so are paleosciences a preview of Earth's future. “
Thank you.
Everette L. Wampler