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Comments 86901 to 86950:

86901. Ken Lambert at 21:09 PM on 30 April 2011
       A Flanner in the Works for Snow and Ice
       Oops - accidental enter - ignore #143 Thanks for your apology of sorts Tom. We can keep this on first name terms surely. Lets go to Dr Trenberth's paper "Tracking the Earth's Global Energy" Aug09 and make a generous estimate from it: Ref Table 1. These are his estimates: in Joules/year Arctic Sea Ice: 1E20 Ice Sheets: 1.4E20 (half Greenland half Antarctica) Ocean (global): 20-95E20 (average 58E20) For the Arctic estimate of NET heat absorption (incoming minus outgoing): Arctic Sea Ice: 1E20 Ice Sheets: 0.7E20 (including all Greenland loss) Ocean: 4.2% of 58E20 = 2.44E20 for all Earth area above 66N Total: 1 + 0.7 + 2.44 = 4.14E20 Joules/year This assumes that ALL the Greenland ice loss is included and the area proportion (4.2%) of the global average ocean heat absorption even though not all the ice is lost in the Arctic in summer so the average albedo for the whole planet's oceans is implied in using the 4.2% proportion. This is conservative because most of the worlds oceans are ice free and the average albedo would be lower than the Arctic which still has ice in summer. Even if we took the top end of Dr Trenberth's range for global oceans of 95E20 Joules/year, then 4.2% of that would be 3.99E20 and the sum 1 + 0.7 + 3.99 = 5.69E20 Joules/year. With the above conservative assumptions, the NET Arctic range is 4.14 - 5.69E20 Joules/year. Adding in the 4.2% proportion from the global oceans also ignores any transport of heat from elsewhere on the planet, so surely overestimates the effect of absorption Solar heat by albedo decrease due to ice loss of the Arctic surface area by itself. The above 4.14 - 5.69E20 number is still roughly half the NET 9.17E20 Joules/year you are claiming from Flanner.
86902. Tom Curtis at 20:31 PM on 30 April 2011
       Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
       angusmac @35, Dana clearly shows the correlation between the data the "prediction" for scenario C in figure 1. This correlation, however, is purely a consequence of Hansen using a climate sensitivity of 4.2 degrees C per doubling of CO2. Dana shows the consequences adjusting the prediction for the IPCC accepted climate sensitivity in figure 3, in which the adjusted scenario B prediction underestimates the temperature data. Of course, the scenario C prediction using a climate sensitivity of 3 would perform far worse than does the scenario B prediction.
86903. Marcus at 18:38 PM on 30 April 2011
       CO2 is plant food? If only it were so simple
       "I worked 10 years (including: for the Department of Agriculture - the U.S.) on the influence of climate on aphids - and their "enemies” (10 years I taught the students of agriculture, what you should know about: pest control - climate)." So on the basis of a *single* example, & not a very consistent one at that, you make broad generalizations-how typical of you Ark. Did you factor in the effects of raised CO2 levels as well as temperature? Many studies I've read suggest that breeding cycles of many insect pests will be enhanced by a combination of warmer weather & increased CO2-which would tend to trump your interesting, but hardly convincing, anecdotal "evidence". There is also the FACE study that shows reduced plant resistance to insect predation under eCO2 conditions. I've also read that eCO2 makes herbicides less effective-thus making invasive weeds an even bigger problem in crop management. I've already raised the implications of the results regarding the impacts of eCO2 on soil-borne pathogens. These 3 factors alone (Insect Pest numbers/plant resistance, Weed Numbers/Herbicide Efficacy & soil-borne pathogens) really don't leave your own anecdotal evidence standing up too well-& certainly makes Bubyko's position look very shaky (still, you've proven to have a habit of putting people's unfounded opinions ahead of the bulk of established science). "It is generally thought that it was mostly dry conditions in warm climates limit the positive effects of increase p.CO2 for photosynthesis - the yield of crops. But let us be careful of such conclusions." Why Ark? The two instances are completely different. Any climate change which occurred over the MWP did so over a space of several *hundred* years-& even peak temperatures were not believed to be much higher than they were around the 1970's. What this means is that crops had several hundred years to adapt to what would have been pretty modest changes in climate, whereas current crops need to adjust to climate changes in the space of little more than 100 years, as well as coping with any negative effects of rising CO2 *at the same time*. Also, its worth pointing out that famines were hardly limited to the 13th & 14th century-they also feature in many of the previous centuries, & were not limited strictly to Europe. I suggest you check your facts a bit better in future.
86904. Philippe Chantreau at 17:57 PM on 30 April 2011
       Medieval project gone wrong
       Each tree ring shows early wood and late wood. The early wood is the one more dependent on spring prescipitation. Gallopingcamel, you could have found this in a few seconds on Google. http://en.wikipedia.org/wiki/Dendroclimatology
86905. RSVP at 17:39 PM on 30 April 2011
       Waste heat vs greenhouse warming
       muoncounter 406, mclamb6 407 "How do you know that?" This is dictated by heat transfer fundamentals. Heat transfers via conduction, convection, and radiation. In all three cases it always goes from a material with a higher state of energy to a lower state of energy. All materials behave this way, so heat always migrates from a warmer place to a cooler place. This is what the word "dissipation" in the article refers to. In Phoenix Arizona, you have a daylight pulse wherein the net heat builds, yet even so, heat is constantly radiating, even during the day. This loss of heat due to radiation, is considered "cooling", because not all the heat from the Sun is accumulating. Given the respite night provides, most of the heat taken in during the previous day gets radiated out into space, and its then that cooling is most noticable. Heating from all the air conditioners running in Phoenix offsets the natural thermal equilibrium that existed in nature. It can only be warmer in Phoenix as a result of these and other human induced heat sources. And although temperatures in Phoenix might be a tad higher, this extra energy is drawn off by surrounding desert air due to thermals and cyclical wind conditions. This extra energy is not lost however and dissipates as the article states. The cumulative effect of heat generated from industry in the northern hemisphere acts like a thermal noose around the Artic. That GHG should affect the entire planet equally refers to the assumption that CO2 is in general evenly distributed throughtout the atmosphere. So to whatever extent CO2 has acted in the past as GHG (whether locally or otherwise), it should do so in like manner even as its concentration rises.
86906. angusmac at 17:06 PM on 30 April 2011
       Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
       Illuminating post Dana but you neglect to mention that Hansen's Scenario C actually gives the best fit to the GISS temperature data, not Scenario B. See the chart below.
       Moderator Response: [DB] Umm, no. See here for robust discussion, where you previously advanced this misunderstanding and were provided edification (please put future discussions of this there as well). Repeating a misunderstanding does not unmake it as a misunderstanding.
86907. Marcus at 17:05 PM on 30 April 2011
       CO2 is plant food? If only it were so simple
       @ Arkadiusz Semczyszak ....and, as before, you've given us *no* real evidence to back your claims. Where is the proof that famines in the 13th & 14th century were actually caused by climate? They certainly weren't caused by lower levels of CO2-which were at 280ppm throughout that entire time. I'd actually argue that a big part of any famines during that time period might have been the fact that the bulk of the rural labor force had been wiped out by The Black Death-or perhaps you hadn't ever heard of that?
86908. Tom Curtis at 15:30 PM on 30 April 2011
       Models are unreliable
       trunkmonkey @349: First, the primary long term consequence of life to the physics of Earth is that Entropy is increased by is presence by a significant degree more than it would have been in its absence. So from the physics perspective, life very much acts according to the spirit of the 2nd Law of Thermodynamics. Second, the rest of your post reads like nothing other than an example of the hubris of ignorance - the belief of a person that because they themselves do not know particularly much on a subject, therefore nobody knows much more. If this is all the argument you have to offer - the vaunting of ignorance, then you have no argument, only an unwillingness to follow the evidence.
86909. Tom Curtis at 15:19 PM on 30 April 2011
       Medieval 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.
86910. gallopingcamel at 15:00 PM on 30 April 2011
       Medieval 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.
86911. trunkmonkey at 14:53 PM on 30 April 2011
       Models 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)
86912. adelady at 14:43 PM on 30 April 2011
       Medieval 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.
86913. Tom Curtis at 14:37 PM on 30 April 2011
       How 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.
86914. Tom Curtis at 14:01 PM on 30 April 2011
       A 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).
86915. Bob Lacatena at 13:34 PM on 30 April 2011
       Medieval 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.
86916. Ken Lambert at 13:06 PM on 30 April 2011
       Lindzen 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?
86917. Ken Lambert at 12:30 PM on 30 April 2011
       A 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.
86918. Ken Lambert at 12:10 PM on 30 April 2011
       How 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.
86919. jyyh at 12:08 PM on 30 April 2011
       Wakening 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.
86920. pbjamm at 10:27 AM on 30 April 2011
       Medieval 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.
86921. Daniel Bailey at 09:41 AM on 30 April 2011
       Climate 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
86922. scaddenp at 09:31 AM on 30 April 2011
       Medieval project gone wrong
       So the obvious citizen science project would be to replicate the map but do all the graphs correctly.
86923. dana1981 at 09:18 AM on 30 April 2011
       Lindzen 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.
86924. Bob Lacatena at 09:17 AM on 30 April 2011
       Lindzen 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.
86925. Tom Curtis at 09:14 AM on 30 April 2011
       Lindzen 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?
86926. Stephen Baines at 09:09 AM on 30 April 2011
       Lindzen 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.
86927. Nyq Only at 09:08 AM on 30 April 2011
       Climate Change Denial book now available!
       Kindle version please! Ta, thanks very much :)
86928. David Horton at 08:57 AM on 30 April 2011
       Medieval 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.
86929. dorlomin at 08:52 AM on 30 April 2011
       How 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.

86930. johnd at 08:39 AM on 30 April 2011
       Lindzen 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”
86931. Philippe Chantreau at 08:29 AM on 30 April 2011
       Medieval 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.
86932. skywatcher at 08:25 AM on 30 April 2011
       How 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...
86933. mclamb6 at 07:08 AM on 30 April 2011
       Waste 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"?
86934. muoncounter at 07:08 AM on 30 April 2011
       Waste 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?
86935. Same Ordinary Fool at 06:52 AM on 30 April 2011
       Medieval 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
86936. RSVP at 06:35 AM on 30 April 2011
       Waste 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.
86937. skywatcher at 06:27 AM on 30 April 2011
       Medieval 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.
86938. Alexandre at 06:12 AM on 30 April 2011
       Medieval project gone wrong
       NewYorkJ #9 Oh, now see it. Thank you.
86939. arch stanton at 05:05 AM on 30 April 2011
       Cosmic ray contribution to global warming negligible
       Philipe #48, Thanks for the links. Indeed the process is convoluted. and size is important.
86940. NewYorkJ at 04:50 AM on 30 April 2011
       Medieval 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.
86941. JMurphy at 04:41 AM on 30 April 2011
       Medieval project gone wrong
       None of the graph links seem to work for me.
       Moderator Response: [DB] Sorry, JMurphy; should be fixed now.
86942. Alexandre at 04:29 AM on 30 April 2011
       Medieval 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?
86943. NewYorkJ at 04:18 AM on 30 April 2011
       Medieval 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!

86944. JMurphy at 03:54 AM on 30 April 2011
       Medieval 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...
86945. Bob Lacatena at 03:42 AM on 30 April 2011
       Medieval 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.
86946. dhogaza at 03:34 AM on 30 April 2011
       Medieval 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.
86947. Chris G at 03:03 AM on 30 April 2011
       Climate 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
86948. Chris G at 02:53 AM on 30 April 2011
       Climate 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.
86949. HumanityRules at 02:46 AM on 30 April 2011
       Medieval 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'
86950. Chris G at 02:30 AM on 30 April 2011
       Climate 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...

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