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Tom Curtis at 15:19 PM on 30 April 2011Medieval project gone wrong
gallopingcamel @19, trees ,like everything else, need a lot of factors in their favour to grow well. They need sufficient water, sufficient sunlight, a lack of too many boring or grazing pests, nitrogen in the soil, healthy root fungi to take in soil nutrients, and of course, sufficient warmth. (The list is not exhaustive.) Also like everything else, the thing which limits the growth rate most is the thing in least supply. Trees in the tropics rarely lack sufficient warmth, but lack of water, or too many pests can be major problems. In contrast, trees on the edge of a tree line due to latitude or altitude certainly lack warmth. In fact, they are restricted to so short growing season by lack of warmth that if, on average over a decade or so, it was any shorter, they would not grow at all. Hence the tree line. So, the factor which most determines the growth rate (and hence tree ring width) of trees varies with location, and even from tree to tree. Even the difference between being on the North slope or South slope of a hill can make a difference, due to changes in incoming sunlight. Or the difference between being on the East or West slope, which can modify precipitation and wind strength. The important thing is that these factors can be judged by carefully examining the local geography, and by checking the trees for signs of scarring that results from pests, disease or excess grazing. By doing so you can check if the primary factor is water, or disease, or temperature. Paleoclimatologists choose the trees which are suitable for what they are trying to study. -
gallopingcamel at 15:00 PM on 30 April 2011Medieval project gone wrong
Hi y'all, While I have not spent much time here lately owing to pressure of work and an increasing involvement in "Brave New Climate" the MWP title caught my eye. One of the things I liked was this quote from Zhang et al. (2003): QUOTE ... We find that the annual growth rings mainly reflect variations in regional spring precipitation........ UNQUOTE I think this implies that dendochronology is affected by more than a single variable. If the above quote is correct April showers can have a greater effect on tree growth than average temperature. Likewise, studies of climate issues in 16th century Mexico use tree rings to track rainfall rather than temperature. Can any of you learned gentlemen explain why Michael Mann uses dendochronology to track average temperature?Moderator Response: [DB] Your answer is here. -
trunkmonkey at 14:53 PM on 30 April 2011Models are unreliable
Physics does not handle emergent properties well. Life itself, while not violating the letter of the second law of thermodynamics, definitely violates the spirit. At the risk f heresy, I am confessing straight away that I believe there may be a law or two of thermodynamics undiscovered. Particularly as regards life and emergent properties. I can understand how you guys feel that if you have the physics nailed down, the paleo stuff barely matters. It's a brave new world, the Anthropocene anyway. When I hear, "The data are all bounded."; "The broad brush stokes have been made."; I caution the hubris of the cowboy who arises to find his charges have jumped the fence. Such are emergent properties. (I'm restraining myself here due to the excessive breadth of previous posts) -
adelady at 14:43 PM on 30 April 2011Medieval project gone wrong
I have to agree about that map in figure 2. I gave up 40 mins of my life I'll never get back just tabulating and cross-matching the time periods for each graph/ area. The so-called MWP arising from this data only works if you allow 800 years (700 to 1500, more if you include all of the SH records), and overlook the fact that some areas show cooling smack in the middle of the range. And the NH and SH are out of synch by at least a century. Couldn't be bothered turning it into anything worthwhile. The whole idea that the graphic demonstrates anything at all is just rubbish. -
Tom Curtis at 14:37 PM on 30 April 2011How climate change deniers led me to set up Skeptical Science website
Ken Lamber @34, Dr Trenberth's "travesty" is that "observations are inadequate to back up" just one aspect of "the theory and models". The theory and models are well supported by a range of other observations, and so are not reasonably in doubt, as Trenberth would no doubt tell you. Please note that this is not a case of an observation being made which falsifies AGW. Rather this is a case of an observation we would like to make to further support the evidence of AGW, but are as yet unable to make. -
Tom Curtis at 14:01 PM on 30 April 2011A Flanner in the Works for Snow and Ice
Ken Lambert @141, Flanner does not, SFAIK estimate the total additional energy absorbed by the arctic (net increased energy minus net increased outgoing energy). Rather, he estimates a forcing change per degree K averaged over the Northern Hemisphere. That can be turned into a value for net additional energy simply by multiplying by the surface area of the NH and and the actual change in temperature over the period; or to an actual globally averaged forcing by halving the value and multiplying by the temperature gain. These are also appropriately called Flanner's estimates IMO in that they constitute only a change of unit, and a multiplication by the actual temperature increase. They are not a quotation, and I am never claiming to quote somebody unless I enclose the text in exclamation marks. The "estimate" you quote in the surviving part of post 141 was in error (and as that is simple arithmetic, I can only plead exceptional tiredness as an excuse). The "correct" value is Flanner's value of 6.2 W/m^2 estimate is given in my 137. Again, more correctly it is my estimate based on Flanner's figure for NH radiative forcing, but again simple arithmetic takes you from one to the other, and you can double check the arithmetic for yourself. I apologize for any confusion. Finally, even if the Flanner based estimate were 3.4*10^20 Joules rather than the better 9.17*10^20 Joules, you would still not have shown my 17 or 18*10^20 Joules per summer season (not year) estimates where incorrect. This is because those estimates were of the increase in incoming energy flux, while Flanner's is an estimate of the increase in incoming energy flux minus the increase in outgoing energy flux. To show an inconsistency you would have to show the outgoing energy flux did not increase by around 9*10^20 Joules, however, if we were to go down that route we would need to find a much better estimate of the increased incoming flux than mine (which remains a significant underestimate). -
Bob Lacatena at 13:34 PM on 30 April 2011Medieval project gone wrong
15, scaddenp, I actually started that project, but I had access to so few of the actual papers (unless I was ready to shell out hundreds of dollars in purchases and subscriptions, just to prove a point) that I abandoned it. It was kind of fun, seeing the whole thing really crumble. In the end, though, I think Mann 2010 pretty much did what needed to be done. -
Ken Lambert at 13:06 PM on 30 April 2011Lindzen Illusion #1: We Should Have Seen More Warming
dana1981 #103 If Lintzen is right, "we should have seen more warming", does that imply the current warming imbalance (+0.9W/sq.m) is reducing? Does anyone have later information on the summation of 2005 forcings shown at the top in Figure 1? -
Ken Lambert at 12:30 PM on 30 April 2011A Flanner in the Works for Snow and Ice
MC #140 ( -Moderation complaint snipped- ). I might as well talk to you MC ( -Inflammatory snipped- ). Is Tom's quotation of Flannner right?: viz "More importantly for this thread, Flanner estimates that the increased net energy absorption (additional energy absorbed - additional energy lost) due to arctic sea ice melt is around 5*10^20 Joules, or approximately 42% of the conservative estimate of additional incoming energy flux. As Ken would say, this is quite close to Trenberth's figure of 3.4*10^20 Joules needed to explain melting and warming of Arctic ice." If so, have I not made my case against the 17E20 and 18E20 Joules/year numbers which Tom was talking about?Moderator Response: [DB] Your comment was deleted due to a pervasive use of all caps; a violation of the Comments Policy. -
Ken Lambert at 12:10 PM on 30 April 2011How climate change deniers led me to set up Skeptical Science website
JMurphy #30 "Knowing your opinion of him and his work (you seem to view him as an "advocate of AGW", rather than a unbiased scientist seeking the facts), that is over-generous of him. Makes me wonder, though, why you haven't asked him to appear here yourself, to discuss these matters to your satisfaction." Well you have a good point JMurphy. I have emailed John Cook about it on a couple of occasions, and being respectful of the ownership of this site, I did not want to preempt what John might do. Watch this space. Dr Trenberth clearly believes in the theory and models which identify CO2GHG the main cause of the last 30 years or so of surface temperature increase. His 'travesty' is that width and breadth of observations are inadequate to back up the theory and models. His is an honest statement of the observational facts. As said previously - this can go two ways. Dr Trenberth goes for 'its there but we can't adequately measure it', and I am going for the 'if it ain't measured it might not be there', if and until the measurements say more. -
jyyh at 12:08 PM on 30 April 2011Wakening the Kraken
Excellent, thanks and a bow. That would be 'Revontulimeri' in finnish. I might as well take the Quenya version, though the finnish language commission may have something against it. -
pbjamm at 10:27 AM on 30 April 2011Medieval project gone wrong
Sphaerica and Philippe Chantreau Add me to your ranks as well. The utter nonsense that was put forward as fact and conspiratorial tone made it impossible for me to take them seriously. Much like the Jerry Springer show actually, which for non-americans was traditionally viewed while drunk. -
Daniel Bailey at 09:41 AM on 30 April 2011Climate Change Denial book now available!
I must also signal for a Kindle version, John. My wife gave me one for my birthday, which I'm using to store science papers for later reading. She's threatened to repurpose the Kindle unless I download an actual book to read to it... The Yooper -
scaddenp at 09:31 AM on 30 April 2011Medieval project gone wrong
So the obvious citizen science project would be to replicate the map but do all the graphs correctly. -
dana1981 at 09:18 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
As Stephen noted in #31, what matters is the net forcing, not how much came from CO2 or methane or ozone etc. Scenario B was closest to the actual observed net forcing, and I adjusted it to more accurately reflect the actual forcing in "Adjusted Scenario B." To be honest, I don't really know what point johnd is trying to make. -
Bob Lacatena at 09:17 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
30, johnd,In order to claim that the Hansen Scenario B is the closest to reality is to accept that each of the above has come to pass, otherwise any similarity of the prediction to reality is more due to accident rather than design.
You don't seem to understand matters. The scenarios aren't predictions, they're... scenarios. Hansen isn't and was never in the business of predicting economic growth and fossil fuel use, and he couldn't very well make a prediction for every possible variation in CO2 output. So he came up with three broad scenarios modeling future CO2 emissions, each using a set of assumptions. That the assumptions were wrong, but reality's CO2 levels track closer to one scenario than the others, and so makes the predictions which accompany that scenario the best to consider. It's one thing to claim his climate predictions were wrong (which they obviously weren't), but... to claim his economic "predictions" were wrong? Sheesh. -
Tom Curtis at 09:14 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
johnd @30, Hansen described three scenarios. In order to claim that scenario B is closer to reality than either of the others we need only show that it is closer to reality than either scenario A or C - which it is. Are you seriously suggesting that because Hansen's scenario B (not prediction, bu scenario) is not a perfect match to reality that denier's continuously insisting that scenario A is a better fit is justified? -
Stephen Baines at 09:09 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
"In order to claim that the Hansen Scenario B is the closest to reality is to accept that each of the above has come to pass, otherwise any similarity of the prediction to reality is more due to accident rather than design." No johnd. As has been discussed in other posts, it doesn't matter what leads to the forcing. As long as the forcing in scenario B and the realized forcing are approximately the same, scenario B and reality are comparable. -
Nyq Only at 09:08 AM on 30 April 2011Climate Change Denial book now available!
Kindle version please! Ta, thanks very much :) -
David Horton at 08:57 AM on 30 April 2011Medieval project gone wrong
Well investigated Hoskibul. My only quibble is with the title. This isn't a "Medieval project gone wrong", but a "Medieval project gone right". Does anyone seriously believe you could cherry pick and misrepresent the data like this by accident? And it serves its purpose, to obfuscate, confuse, give deniers easy ammunition for use in threads and on talk back radio, delay and delay and delay. And it's all working beautifully. -
dorlomin at 08:52 AM on 30 April 2011How climate change deniers led me to set up Skeptical Science website
Interesting comment about the 'it's the Sun' argument - is it the contribution of this site, or are people realising that the divergence of solar activity and climate indicators in the past couple of years = = = = = = = = = = = = = = = Its Johns illustration of that that has been the most powerful tool I have on the Guardian website to rebut the 'its the sun' argument. There are most likely other versions of the image around but where ever I am on the net, a link to that one jpeg hands the initiative to the argument my way. A few come back with variations of Svennsmark or Lockwood 2010 (I mean seriously), but it normally sends them off down the road of broken hockey sticks and hidden declines, the sun rarely rises aften that jpeg.Response:[DB] Fixed text.
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johnd at 08:39 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
Hansen set the following interrelated parameters in his 1988 paper. "In scenario B the growth of the annual increment of CO2 is reduced from 1.5%/yr today to 1%/yr in 1990, 0.5%/yr in 2000 and 0 in 2010; thus after 2010 the annual increment in CO2 is constant, 1.9 ppmv/yr. The annual growth of CCI3F and CCI2F2 emissions is reduced from 3%/ yr today to 2%/year in 2000 and 0 in 2010. The methane annual growth rate decreases from 1.5% today to1% in 1990 and 0.5%/yr in 2000. N2O increases are based on the formual of Weiss (1981), but the parameter specifying annual growth in anthropogenic emission decreases from 3.5% today to 2.5% in 1990, 1.5% in 200, and 0.5% in 2010. No increases are included for other chlorofluorocarbons, O3, stratospheric H2O, or any other greenhouse gases." In order to claim that the Hansen Scenario B is the closest to reality is to accept that each of the above has come to pass, otherwise any similarity of the prediction to reality is more due to accident rather than design. Of course there is one more condition that it all relied on, that is the conditions in the oceans, “Our procedure is to use simple assumptions about ocean heat transport. Specifically we assume that during the next few decades the rate and pattern of horizontal ocean heat transport will remain unchanged and the rate of heat uptake by the ocean beneath the mixed layer can be approximated by the diffusive mixing of heat perturbations” -
Philippe Chantreau at 08:29 AM on 30 April 2011Medieval project gone wrong
I have to join Sphaerica. The "skeptic" blogs are the one factor that seriously tipped me. I was not initially under the impression that there was significant scientific debate about GW. Then I ran across those sites, which at first glance suggested that there was. When I started reading, I could hardly believe my eyes. There have been only a few things that truly shocked me since I moved to the States. One was the Jerry Springer show (I still have a hard time to believe that there are people who actually watch this stuff). Another was the tandem Climate-Audit/WUWT and other so-called skeptic blogs. There was all the stuff that I learned about in high school, when we analyzed marketing, advertisement, mind manipulating methods, the Eastern block state run media, etc, etc. It was so blatant, I could hardly believe that anyone would fall for it. Yet, it is quite successful, even with people who should know better. For me, it removed any doubt as to where the sincere pursuit of understanding is to be found. Even if the fundamental tenets of climate science turn out to be wrong, it won't be because of anything discovered by these fools. They don't discover anything anyway, just spread lies and misinformation. -
skywatcher at 08:25 AM on 30 April 2011How climate change deniers led me to set up Skeptical Science website
Remarkable attempts to derail the comments here! I headed into this area by way of hearing Ray Bradley Speak in Colorado about RealClimate and dealings witha certain Sen Inhofe, and that opened my eyes to just how poisonous the atmosphere was, even in 2004. Skeptical Science is still, to me, the best source of clear information to support rebuttals of a great variety of skeptic argiments. Other sites may provide greater detail about particular topics (RealClimate being one, of course), but it is fantastic to be able to go to a site and identify some key papers and eloquent arguments pertinent to a particular topic. Even if those papers have been superseded in intervening years, they are usually a good enough reference point, or starting point to identify other, more recent contributions. So all hail your 'inner-computer geek', John, as it has surely helped a great many people out there by providing a tremendously valuable resource! Interesting comment about the 'it's the Sun' argument - is it the contribution of this site, or are people realising that the divergence of solar activity and climate indicators in the past couple of years (record solar min, near-record high temps) becoming something closer to 'undeniable'? Scratch that, someone, somewhere will be denying it... -
mclamb6 at 07:08 AM on 30 April 2011Waste heat vs greenhouse warming
RSVP @ 405: If "heat transfer" means warmer places cool and vice versa and that, under this proposition, the heating of the Arctic is a fingerprint of waste heat, where is the concomitant cooling of warm places? Why, as I sit in Phoenix, AZ, am I not experiencing any type of cooling trend? Also, from where do you get the idea that a "GHG effect should affect the entire planet equally"? -
muoncounter at 07:08 AM on 30 April 2011Waste heat vs greenhouse warming
RSVP#405: "warming of cooler places like the Artic and glaciers is waste heat's fingerprint." How do you know that? Do you have any research to back it up or is it just another unsubstantiated assertion? Where are the waste heat sources in the Arctic? "A GHG effect should affect the entire planet equally." How do you know that? Do you have any research to back it up or is it just another unsubstantiated assertion? Do you know what Arctic amplification is and why the GHG should not warm the planet equally? -
Same Ordinary Fool at 06:52 AM on 30 April 2011Medieval project gone wrong
Soon & Baliunas(2003) used these deceptions, and one more. They compared MWP temperatures to the average temperature for the 20th century, rather than recent temperatures. Craig Idso and Sherwood Idso (of the CO2 Science website) were co-authors when Soon and Baliunas published (three months later) a longer version of this paper in E&E. See Wikipedia: Soon and Baliunas controversy -
RSVP at 06:35 AM on 30 April 2011Waste heat vs greenhouse warming
Heat transfer is always from hot to cold. The article states... "This heat doesn't just disappear - it dissipates into our environment." A better word for "dissipation" is heat transfer, which means that warmer places loose their heat (i.e., cool), and cooler places warm up. The warming of cooler places like the Artic and glaciers is waste heat's fingerprint. A GHG effect should affect the entire planet equally. This is not what is happening. -
skywatcher at 06:27 AM on 30 April 2011Medieval project gone wrong
Oh dear - that site is a bad one. I thought I'd follow up a paper from a region whose research and climate I know well (Iceland, coincidentally), and looked up what they said about Sicre et al (2008). Of course the website suggested that the MWP was 1C warmer than the 'modern warm period' according to Sicre et al. An interesting conclusion to reach, given that the Sicre record is truncated at 1950AD and so does not show the 'modern warm period'... It really is classic misinformation, and well done Hoskibui for the debunk. -
Alexandre at 06:12 AM on 30 April 2011Medieval project gone wrong
NewYorkJ #9 Oh, now see it. Thank you. -
arch stanton at 05:05 AM on 30 April 2011Cosmic ray contribution to global warming negligible
Philipe #48, Thanks for the links. Indeed the process is convoluted. and size is important. -
NewYorkJ at 04:50 AM on 30 April 2011Medieval project gone wrong
Alexandre, You're missing the 1997-2007 mean annual line. See figure 6a. Note that the blue line ends around 1980 (this is hard to tell from figure 6b, which is on a much larger timescale), therefore missing the sharp recent warming and the recent decade average. This is one of the common visual ploys sites like co2science rely on. One might assume from figure 6b that the end of the line represents modern temperatures. -
JMurphy at 04:41 AM on 30 April 2011Medieval project gone wrong
None of the graph links seem to work for me.Moderator Response: [DB] Sorry, JMurphy; should be fixed now. -
Alexandre at 04:29 AM on 30 April 2011Medieval project gone wrong
Thanks for the post, Hoskibui. I have already come across this website, and indeed many of the studies they cite as "proof of MWP" are either not about temperatures, or not about the same period. I did not spot that on top of that they misrepresented others as well. I'm pretty confident that if they put this all together in a comprehensive global climate reconstruction study, going through all the statistic and geographical distribution issues, they'd get pretty much the same results the other reconstructions show. I did not get the conclusion about Figure 6b, though: it does look like it shows higher temperatures at the MWP than today. What am I missing? -
NewYorkJ at 04:18 AM on 30 April 2011Medieval project gone wrong
Nicely done. There appears to be a grammatical issue with this sentence: "They conclude that current warming is not unprecedented since there was a lot of warming during in the past at various places."Response:[dana1981] Thanks, I revised that sentence. Hoskibui is from Iceland, I believe, so we tried to help him with the translation to English, but may have missed a few of these. But he gets the point across!
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JMurphy at 03:54 AM on 30 April 2011Medieval project gone wrong
Sphaerica wrote : "Really, the effort was/is shockingly disingenuous." Agreed, but to what end, I wonder ? What do the Idsos get out of all this ? Actually, the CO2Science Medieval Project's list of so-called proof of a MWP, reminds me of another little list that some have used to vainly try and 'prove' peer-reviewed skepticism of AGW Alarm... -
Bob Lacatena at 03:42 AM on 30 April 2011Medieval project gone wrong
I love CO2 Science and Science Skeptical. Those were the two sites that really sold me on how far the denial camp would go in misrepresenting facts. I got there shortly after I'd begun to realize that "skepticism" was all smoke and mirrors, all the time. The sites pretty firmly opened my eyes to the difference between science and snake-oil sales. I went through every citation on both sites at the time (looking directly at the real source study, whenever available) and was shocked at what I saw. My very favorite was when they quote Thomspon et al (2003). That paper presents a wide overview of ice cores around the globe... I count a dozen. Our skeptical friends picked the one graph of twelve (one of three from the SA Andes) that barely showed warming around 1100. No mention of the other 11 that directly contradict that single entry, even though two of them are in close physical proximity to theirs, demonstrating that not only wasn't their choice a good global proxy, but it wasn't even a very good local proxy. Other favorites included a paper whose data only went from about 1600 to the present, one hand drawn graph with no units of measure on either axis, one paper repeated twice, and a paper that explicitly said that its data should not be used in any way as a global or even regional temperature proxy. The single biggest flaw that recurred over and over was the fact that any warming peak in a 1,000 year span was labeled as MWP, even if it only appeared to last 50 years, and differed from other studies by hundreds and hundreds of years. Really, the effort was/is shockingly disingenuous. -
dhogaza at 03:34 AM on 30 April 2011Medieval project gone wrong
HR:Just as a side point when a scientist publishes that doesn't give them exclusive rights to describing the implications of their data.
Fair enough, but even if your interpretation is right, their point is that their data implies solar variation appears to be responsible during the MWP detected by their reconstruction. I'm sure HR read that part and understand it, so won't bother reproducing it here. We know from observations that this is not true today, so any suggestion that this study points to a low sensitivity to changes in atmospheric CO2 concentrations is just bull pucky. -
Chris G at 03:03 AM on 30 April 2011Climate Change Denial book now available!
Apologies, I found that these comments would fit under an existing topic: Climate Emergency: Time to Slam on the Brakes -
Chris G at 02:53 AM on 30 April 2011Climate Change Denial book now available!
OK, there is something about someone helping those who help themselves, or is it ask and you shall receive? Anyway, to close off my derailment of this thread, I think I found what I was looking for. I skimmed titles and abstracts until I found this "Slowing down as an early warning signal for abrupt climate change which looked promising, but I wanted to see if it was a reputable work. So, I followed the link to citations, and found: Copenhagen Diagnosis which I am sure is familiar, and contains: "Is there any prospect for early warning of an approaching tipping point? Recent progress has been made in identifying and testing generic potential early warning indicators of an approaching tipping point (Lenton et al. 2008; Livina and Lenton 2007; Dakos et al. 2008; Lenton et al. 2009; Scheffer et al. 2009)..." On the first skim read, it does not support those who say there is nothing to worry about because things are not changing as fast in the most recent decade.Moderator Response: [DB] You may want to try this one: Regime shifts in ecological systems can occur with no warning, Hastings and Wysham, 2010. -
HumanityRules at 02:46 AM on 30 April 2011Medieval project gone wrong
With regard to the Mangini paper do you think the CO2 Science people are taking their lead from this part of the paper? "We observe the lowest values in the section formed during the Little Ice Age (AD 1400–1850), and maximum values in the section corresponding to the MWP (approx. AD 800–1300). These latter values are even slightly higher than those of the top section of the stalagmite (1950 AD) and higher than the present-day temperature of 1.8oC." It just seems the CO2 Science people have quantified 'slightly'. Fig3 suggests they have done that correctly. Just as a side point when a scientist publishes that doesn't give them exclusive rights to describing the implications of their data. Falsehoods about the data is obviously unacceptable but reappraisal of conclusions and interpretations seems OK. I don't see how what the CO2 Science people did with the Mangini paper constitutes a 'trick' -
Chris G at 02:30 AM on 30 April 2011Climate Change Denial book now available!
errm, Google Scholar on "bifurcation theory climate change" indicates I have some reading ahead of me. If there is a summary article someone knows of... -
Chris G at 02:18 AM on 30 April 2011Climate Change Denial book now available!
I know this is off topic, but may I request a topic for future discussion? I've been thinking off and on for some time about signs or indications that a system is on the verge of a regime change, in particular with respect to climate. My gut feel assessment has been that unusual levels of variance from the mean would increase for some time before reaching the tipping point after which the status would not return to the previous conditions. So, it was with interest that I read this story about an ecological system regime change. Apparently, my thoughts are nothing new; there exist models which are used to examine state changes within a variety of system types and predict when a tipping point is about to be reached. I can understand that predicting a tipping point using the multitude of physics processes involved in climate is extremely difficult. I was wondering if serious work has been done along an alternate line of looking at not the physical processes, but just the amount of variation from pre-existing conditions. Snippet: "Brock used a branch of applied mathematics known as bifurcation theory to show that the odd behavior was in fact an early warning of catastrophic change. In short, he devised a way to sense the transformation of an ecosystem by detecting subtle changes in the system's natural patterns of variability." -
MattJ at 02:17 AM on 30 April 2011Medieval project gone wrong
Howard Duff's marvellous little classic, "How to Lie with Statistics" also had a brilliant expose/exposition of these "common graphical tricks". I wish I could cut and paste them here, but mine is a paper copy, and I am no good with computer drawing:( But his illustration of the 'trick's is persuasive, memorable, and concise. It boggles the mind to think how timely his little book still is. The deceivers have not even had to bother to think up new techniques since the 50s when he wrote his book! -
Tom Curtis at 02:12 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
tonydunc @23: 1) "he says that ONLY scenario A is reasonable to compare to Hansen's predictions." In the original paper Hansen says that scenario A is . He also says (page 9361) that in scenario B the rate at which CO2 growth increases will decline so that by 2010 (and after) the increase will be a constant 1.9 ppm per year. The following is the increase in CO2 content in ppm per year as plotted by Tamino:
Turns out that in 2010, CO2 growth was under 1.9 ppm, although the trend was probably very close to it.
Hansen also said the annual growth of the increase in CO2 concentration in scenario A is 1.5%, or a 1.015^30=~= 1.56 increase in the annual growth rate over the 30 years from 1980 to 2010. With a start value of 1.4 ppm growth in CO2 concentration in 1980, that predicts around 3 ppm growth rate for 2010, or 50% greater than the trend or nearly double the actual value.
Clearly scenario B is much closer to what occurred.
2) "He used Hansen’s temperature data to verify Hansen’s predictions. That is like trusting Al Gore’s lawyers to count ballots in Florida."
For this argument to make any sense, it would be necessary that using a different temperature series would make the data fit Lindzen's "prediction" better than Hansen's. Well, take your pick:
No matter which temperature series you use, the data still supports Hansen's prediction. Indeed, John Cook explicitly pointed that out in the article when he said, "GISTEMP is consistent with all the other surface and satellite temperature data sets."
3) "You "offset Lindzen’s start point downwards by half a degree. Obviously the data needs to be normalized before comparing.""
Lindzen's comment quoted in the article indicates that temperatures have increase by from 0.1 to 0.2 degrees from their start point around 1880/89. That makes 1880/89 the start point of his prediction (and retrodiction) and hence the point from which his prediction should be plotted. As the graph only plots from 1958, that creates an apparent offset. At least, that is how I understood the graph.
4) "He drew scenario B below Hansen’s actual scenario B. Note the red line above is too low."
5) He drew Hansen’s measured data too high. The thick red line below and horizontal bars are from the GISS web site. The black line above it is what Cook drew. Hansen reported 0.63 for 2010, Cook placed it above 0.7"
I cannot respond to these points as I do not know the details of the plot. However, given the purpose of the graph, ie, to compare Hansen's and Lindzen's "predictions", would it make Lindzen's "prediction" look any better if the graph was adjusted as Goddard suggests? It strikes me that Goddard is quibbling to distract the punters from how wrong Lindzen got it.
"Finally a commenter on the site says this is a straw man argument since Lindzen has never made any actual predictions."
From the first paragraph of the article, "Although to our knowledge Lindzen has never made any specific global temperature projections, he did make some statements in this talk which we can use to extrapolate what his temperature predictions might have looked like."
It would be hard to be more up front than that.
The suggestion that Cook's article is a strawman argument is a form of special pleading. It is an insistence that the logical consequences of critics of climate science should not be examined.
If you want, however, an example of a real strawman, it is Chilli's claim that, " Cook made the bogus graph by simply removing CO2 from Hansen’s temperature model."
Cook, of course, used to methods to arrive at a hypothetical prediction for Lindzen, both of which he clearly described in the article. Apparently Cook's methods were to reasonable for Chilli (afterall, he surely wouldn't be so dishonest as to criticize an article he hasn't actually read?) so he invented a suitably bogus method to attribute to Cook.
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dana1981 at 01:54 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
tonydunc - this is my post, not John's. Goddard's comments are a bunch of baloney, to put it nicely, but since you asked I will respond specifically."Cook picked scenario “B”...He should be comparing against scenario A"
Actually the plot in question shows Scenario B adjusted to reflect the actual radiative forcing based on measured GHG changes, as I explained in the post. Scenario A is nowhere near reality, nor is Goddard's comment #1."He used Hansen’s temperature data to verify Hansen’s predictions."
As I noted in the post (and linked to supporting evidence), GISTEMP ("Hansen's temperature data") is not statistically different from any other temperature data set. I'm already seeing a pattern in these comments, that Goddard needs to work on his reading comprehension."Cook offset Lindzen’s start point downwards by half a degree."
Again, I explained that my "offset" was based on Lindzen's own comments. This is all discussed in the post."He drew scenario B below Hansen’s actual scenario B"
Again, as explained in the post, I adjusted Scenario B to reflect actual GHG changes."He drew Hansen’s measured data too high."
Shockingly, this is also explained in the post. I took the average of the GISS land-only and land-ocean data because it is most comparable to Hansen's 1988 study. In short, Goddard might want to try actually reading the posts he's going to comment on before criticizing them. Every single one of his criticisms was wrong and was explained in the post. This is pretty sad even by Goddard standards."Finally a commenter on the site says this is a straw man argument since Lindzen has never made any actual predictions. It seems rather odd to me that that would be used as a defense of Lindzen"
Yes, it's a pretty sad defense that Lindzen has never been willing to make a specific prediction of his own. It's easier to criticize than to produce. Nevertheless, Goddard and co. don't seem to dispute the accuracy of my reconstruction. -
Mark-US at 01:40 AM on 30 April 2011How climate change deniers led me to set up Skeptical Science website
Re: [DB]'s reply to #8..... Thanks DB, but credit for POE humor, if any, goes to my debate opponent. That guy is a committed denialist, and argued forcefully for a lot of debunked theories. Sadly, I think they were serious. (Or if it was Poe, it was there way of telling me to shut up!) BTW.... As long as we're doing regionalisms for the Arctic Ocean, how about Lac Lackice? Or "Font Carbon" -
Phil at 01:39 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
tonydunc @23 With regard to point 1. Hansen forecast levels of CO2, Methane, Nitrous Oxides and other trace gases for his three scenarios. Whilst CO2 levels are approximately at Hansen's scenario A, all other trace greenhouse gases are below his scenario C predictions. That means none of the emission scenarios Hansen envisaged actually reflects what has happened. To determine the best emissions scenario you need to consider the nett forcing from all the GHG's he considered. When you do that scenario B emerges as the closest match. -
RSVP at 01:27 AM on 30 April 2011Waste heat vs greenhouse warming
To John Cook By the way, in the orignal article where it points to the IPCC reference: "2.9 W/m2 (IPCC AR4 Section 2.1). " it explains positive radiative forcing and negative radiative forcing, where negative would be something that would have a net cooling effect. Considering the symmetry between positive and negative, how exactly can something have a net cooling effect when it comes to thermal radiation? It could only mean less heat relative to some nominal value, while the 2.9 W/m2 is likewise more heat relative to some nominal value. When talking about less heat, we could only refer to less heat getting in during the day. If the terms positive and negative are symetrical, the 2.9 W/m2 only refers to more heat getting in during the day. Between day and night, this 100x reduces to 2.9 (day) - 2.9 (night) = 0. On the other hand, there is no waste heat day/night since this energy is being expended 24 hrs a day on the average. So the real comparision is 0.028 to 0. -
Albatross at 01:26 AM on 30 April 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
Tonydunc @23, I would really not concern myself about what someone so throughly discredited as Goddard thinks. Goddard has a very long reputation for mangling and misrepresenting the science and for being inept in scientific matters. Note too how Goddard chooses to misinform from the safety of his blog rather than come here and try to pass of his misinformation. I could say more, but this is Dana'sa post, so I'll let him reply if he feels so inclined. PS: Philippe, Goddard no longer "works" for Watts, apparently Goddard's standards are event too low for Watts. And let us not forget that Steve Goddard is a pseudonym, yet Watts allowed him to frequently post on his blog even though he allegedly has a rule about not allowing people to post under pseudonyms.
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