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Comments 83551 to 83600:

83551. Dr. Jay Cadbury, phd. at 07:02 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       I think the mere existence of sea ice and the ice caps demonstrates the globe is in a cool period. Also, we can verify this by checking the historic GAT versus today's average GAT. We find that earth is below average temperatures. Furthermore, the ice caps are an anomaly and have not existed for much of the history of the earth. Because they have completely melted before, it is nearly impossible to connect today's melting with global warming. To do so would be arguing that "Even though the ice caps have melted before, this time it is different somehow."
       Response:

       [DB] Jay, you're going to have to support your assertions with links to reputable sources if you want your comments here at SkS to remain.  If you continue to make baseless assertions about topics you obviously know little about, then those comments will be simply deleted.

       This is a forum in which the participants discuss the science of climate change.  Opinions are welcome, but they need to be backed up with supportive links to peer-reviewed publications.  Otherwise your comments will be construed as trolling and will be treated as such.

83552. Riccardo at 06:41 AM on 8 June 2011
       Can we trust climate models?
       Dikran no doubt that physics based models are better for long extrapolations because they are constrained. In case of short term extrapolations, though, this advantage ceases to be significant while what is left of the chaotic behaviour (internal variability if you wish) cannot be dealt with. There's a chance that internal variability can be better accounted for statistically. I think that we are not used to this time frame and we have some difficulties to think in the proper way. This problem is often common between specialists in any field. As an example not related to GCM, think about the ocean heat content and the missing heat (if any) that Trenberth and others are pursuing or ENSO related variability. GCMs may even simulate this variability, but no way to have it at the right time, i.e. no way to forecast it. Assimilation may help to predict it and maybe even understand its origin. Probably I just like the idea behind F&K paper while the paper itself doesn't give much insights. Though, I wouldn't simply dismiss it as a skeptic paper.
83553. Bob Lacatena at 06:27 AM on 8 June 2011
       Tony Abbott denies climate change and advocates carbon tax in the same breath
       6, Martin, I don't think that's a bad idea. I've recently done the same with the people who think that greenhouse gas theory violates the 2^nd Law of Thermodynamics. Every paid denial climate scientist (Lindzen, Choi, Pielke Sr., Spencer, Curry, etc.) would strongly refute that idea. They'd lose their jobs and any semblance of respect that they have otherwise. As a side note, on the heavier than air thing, the physics argument is pretty straightforward and undeniable. The key to their problem is that the velocities of the molecules involved are ridiculously high. See this site, for example. This is very straightforward physics and math, but at room temperature, the average velocity of nitrogen (the most abundant molecule in the atmosphere) is computed to be 3,790 miles per hour! For Argon, a trace gas with an atomic weight of 40 (CO₂, by contrast, has an atomic weight of 44), the speed is 850 mph. And that's average. Some are going much, much faster, some slower. In addition to this, the density of the atmosphere means that each molecule is undergoing thousands of collisions per second with other molecules moving just as fast. Add wind (macro scale transport effects) from thermal heating, Coriolis effects, and such, and... The upshot of this is that the gases mix very, very well. They have no chance in the universe of separating by density like a bottle of salad dressing, and to think that they would is childishly simplistic thinking. As a side note, you should point out that Argon is the third most common gas in the atmosphere (0.93%) after oxygen and nitrogen, and this has been measured by scientists. So if CO₂ has to fall out, so must Argon. As a last resort, he should realize the implications of what he is saying. If all CO₂ had to drop down to the surface, there is still enough of it to create a fairly thick layer (I haven't done the calculations to determine how thick). This would in fact suffocate every breathing creature on the face of the earth in minutes. So it's not possible: 1) The speed of individual molecules prevents it. 2) The large scale actions of weather in the atmosphere prevent it. 3) There are other molecules, as large or larger, that are clearly present and well mixed in the atmosphere. 4) If CO₂ did fall to the bottom, we'd all be dead, or rather would have evolved into CO₂ breathing creatures (intelligent plants) and would now instead be arguing about how to stop our own O₂ production from destroying our highly evolved plant-based civilization.
83554. DSL at 05:46 AM on 8 June 2011
       There is no consensus
       Aye, Chuck, what Rob said, and if you think that claims about Seitz's integrity are not well-founded, do some research. Here's a good starting place. Ad hominem is the technique of attacking the individual as a substitute for attacking the individual's ideas. If I say that Seitz lacked moral integrity at times when he was working for the tobacco industry, I am attacking Seitz the man--but it's not an ad hominem attack, because I'm not substituting this argument to avoid confronting Seitz's ideas. Seitz at the very least consistently allowed himself to be strongly associated with people who did lack moral integrity at various times in their lives (unless you subscribe to Randian morality). Consensus is a political subject more than it is scientific. Science provides the evidence, but most people don't have the time to review the science. They still need to engage in the democratic process, though, and so they look for experts to tell them what to think. Consensus works as a strong form of expert testimony. Mass media agents also act as expert testimony in the same way. These agents are opinion makers, and not all mass media agents push the same opinion. There are hundreds of analyses of Fox News that reveal a right-wing (both economic and social, paradoxically at times) agenda. There are perhaps thousands of reports and studies that reveal the same right-wing political stance to be strongly associated with a position that global warming is either not happening, not our fault, or not bad. The first two positions are not consistent with observation and physics (if you have a contrary claim, bring forth the evidence on the appropriate thread). The third position is an ongoing wait-and-see kind of deal, and so far things aren't looking good. The science also supports a high probability that things will get bad. Now, given that, how is making reference to economic conservatives, the self-identified "right," in any way propaganda? Their positions are one of the reasons why a site like this exists. If you looked around a little on any of the threads, you'd see a clear pattern emerging: self-proclaimed libertarians tend to disbelieve that AGW is happening or is bad. Propaganda is a systematic institutional effort to bring about a specific change in beliefs (and it was once an acceptable term). Look at what the Koch brothers (unabashedly economic right-wingers) are doing and tell me that this is not propaganda. Are posters on this site--a site devoted to testing the BS against the science--not allowed to attack the instruments (living and artifactual) of such propaganda when the connection is quite clear? When propaganda bots attack, it is acceptable to attack the human, because the human has ceased to be human and is simply a robot or a paid (sometimes) repeating machine. It is acceptable to attack anyone who willfully ignores evidence and engagement.
83555. Martin at 05:43 AM on 8 June 2011
       Tony Abbott denies climate change and advocates carbon tax in the same breath
       Hi, This is off-topic. But I hope you will be lenient and not delete this post. I have a suggestion. You have an extensive list, several actually, of climate myths and counter arguments. Possibly you could start a new list. This would contain facts about climate change which are supported by various, well known denialists. After all, not every denialist denies every single climate change fact. And I think that a denialist would be much more likely to believe something that Anthony Watts or Lord Monckton had said. The reason I'm making this suggestion is that I had a heated discussion with a colleague today after he mentioned the word "CO2 lie". Apparently, because C02 is heavier than air, it drops to the bottom and lies in a very thin layer just on top of the earth's crust and can therefore not contribute to global warming. Nothing I said convinced him. Then I asked him whose (counter) arguments he could trust. I didn't get a straight answer. But he did say that he would not trust any scientists paid by the state. Chancellor Angela Merkel (I'm from Germany) has corrupted them all. He is a fan of EIKE, a denialist research institute that has never published a peer reviewed paper. Sorry, for not keeping to your comments policy. I do hope you can help me. Wouldn't it be fun to trash an article at wattsupwiththat explaining why according to Lord Mockton they have completely lost it?
83556. Bob Lacatena at 05:21 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       rpauli, *snerk* Not only that... I love the magical thinking that takes place, where your team was winning before you turned the game on, and then things go down hill after you start watching... and somehow it's your fault, and you feel you have to stop watching so they will play better. Maybe if we all just don't notice the ice, and we're very, very quiet and just pretend we're not even here, it will stop melting... [Oh, wait, the best way to be quiet and pretend we're not here is to stop pumping CO₂ into the atmosphere, and by coincidence, that would in fact (eventually) stop the melting. So maybe I should turn the TV off when my team starts to lose...]
83557. r.pauli at 04:58 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Gosh what synced meme timing: http://www.easterbrook.ca/steve/?p=2500 "There’s something compelling about declaring allegiance to one of the weighted random number generators (sports teams, stock picks, etc), selecting which of the narratives to believe based on that allegiance, and then hoping for (and perhaps betting on) which numbers it will produce. Sometimes the numbers turn out the way you’d hoped, and sometimes they don’t, but either way people prefer to believe in the narratives, rather than acknowledge the randomness. There’s a thrill to the process, but at the same time, a strong sense that everyone else’s narratives are delusional."
83558. Dikran Marsupial at 04:52 AM on 8 June 2011
       Can we trust climate models?
       BTW, while I was looking up the URL for trunkmonkey, I found a paper that might be of interest, "Climate Predictability on Interannual to Decadal Time Scales: The Initial Value Problem" which is next on my reading list.
83559. Dikran Marsupial at 04:46 AM on 8 June 2011
       Can we trust climate models?
       Riccardo it is as it should be, "familiarity breeds contempt" as they say, and I am familiar with statistics and you with physics! ;o) The reason I would prefer the physics based model is that extrapolation is safer from a physics based model than a statistical one. If you have a causal model, it is constrained to behave in unfamiliar conditions according to the nature of the causal relationship built into the model. With a statistical model, there is essentially very little to constrain how it will extrapolate. An even better reason to prefer the physics based model is that if you perform enough model runs, the error bars on the projection will be very broad, so the model openly tells you that it doesn't really know. For a statistically based model on the other hand, if you over-fit it (which is essentially what I suspect they have done in combining the GCM and statistical models tuned on the test set), the error bars on the predictions will be unduly narrow, and make the model look more confident of its prediction than it really ought to be. I don't think it really tells us anything about where the limit lies as the GCM they used was not actually the full DePrSys procedure, but only part of it (that they admit doesn't work as well as the full version). It is a traversty that the paper got published without a fair comparison with the full version of DePrSys. As it stands it is essentially a straw-man comparison. There is no reliable evidence that the combination approach is an improvement because they tuned on the test set (again I would not have given the paper my bessing as a reviewer while it still contained tuning on the test set, even with a caveat, as the biases that sort of thing can introduce can be very substantial). One thing they could have done would be to re-run the experiment multiple times using one model run as the observations and a subset of the others as the ensemble. Each time they could perform the analysis again and see how often the combination approach was better. That would give an indication of the "false positive" rate as the GCM would be the true model, so you coulnd't genuinely improve it by adding a statistical component. I suspect this owuld be quite high because of the multiple hypothesis testing and the tuning on the test data.
83560. Riccardo at 04:30 AM on 8 June 2011
       Can we trust climate models?
       Dikran ironically, we're seeing a statistician (you) against a paper based on statistical models and a physicist (me) defending it. Or maybe it's not so ironic. Perhaps it's just because I am a physicist that I see the limitations of the current approach and I appreciate insights coming from different fields that could help overcome those limitations. The shorter the time span of interest the more the chaotic behaviour of the climate system is apparent; deterministic models can't go in this realm. It is clearly shown in this paper, DePrSys performs poorly below one decade. This paper at least tells us something about this limit, which is a usefull information to have, and one of the (maybe) many possible way to go beyond it.
83561. Rob Honeycutt at 04:15 AM on 8 June 2011
       There is no consensus
       Chuck PRIVATE... You need to realize, first, that the video you're commenting on is not a product of the Skeptical Science site. It is a product of Peter Sinclair. I also seem to continually see people inaccurately using the term "ad hom" to anything they believe is insulting. Peter points out in the video that the tactics used by Seitz and others are the same being used against the science of climate change. That makes it, to my understanding, NOT an ad hom attack.
83562. Chuck PRIVATE at 03:57 AM on 8 June 2011
       There is no consensus
       I'm very new to this site. Credit where due: you lay out your arguments fairly well and quite clearly. HOWEVER, I watched your "Crock of the Week" video "32000 Scientists". What are the odds that the only video I've yet clicked would be a statistical outlier that doesn't apply to all your other "Crock of the Week" videos? The surely-typical video in question is an almost completely contentless ad-hominem attack on AGW skeptic Dr. Frederick Seitz, on Fox News, and at one point on "right wing causes", accompanied by lurid video of smokers smoking through their tracheal holes, and movie clips of the retards from "Deliverance". The ending statement is "...or you can die from lung cancer". It is incongruously opposite of the on-topic and content-heavy article it accompanies. It is propaganda at its most obvious and blatant. You have no right to expect your commenters to stick to the science if the material your administrators post does not do the same. Hence this comment of mine is not science because some of your own subject matter is not. And judging from your Comments Policy and several of your moderators' posts, I wonder if I am permitted to point out ANY of this. Your Policy says, "Any accusations of deception, fraud, dishonesty or corruption will be deleted." Propaganda is in fact all of those things, and I have no honest choice but to accuse you of posting propaganda, because you did. Will my comment deleted for telling the verifiable truth? Your Policy also says, "No ad hominem attacks", and in #336, "muoncounter" responds to a commenter by saying: "Criticism of scientific processes is not quickly deleted; criticism of the scientists is." Since your video criticizes Dr. Seitz and his associations but does not deal with his actual ideas, it is ad hominem by the standards of your Policy and should be deleted by the standards of muoncounter. Will your commenters have to continue obeying a prohibition that you yourselves ignore? Do I even dare even mention your Policy in the first place? In #345, "DB" responds to a commenter by saying, "Adherence to the Comments Policy is also not optional. Complaining about having to comply with it is a surefire ticket to forcing the moderators to act. Maybe you might want to perhaps consider other venues with less restrictive policies?" Your policy is fine. Let's see if I need to opt for a "venue" where EVERYONE is held to it. As said: You have no right to expect your commenters to stick to the "science only" if the material your administrators post does not do the same. As I see it, your choices are to 1) loosen up the Comments Policy so that it may devolve to the very low standards set by the "32000 Scientists" video, 2) apply the Comments Policy TO that video and promptly remove it, or 3) delete my comment so that you don't have to face your own contradiction. You should be aware - and I'm sure you are - that one of the skeptics' complaints about AGW believers is that your alleged "consensus" in the IPCC and elsewhere isn't built on science, but on double standards and suppression of dissent. I wonder if THAT is one of your 150+ topics on here...?
       Moderator Response:

       [Dikran Marsupial] The "crock of the week" video is not "our" video, it comes from climatecrocks.com. IMHO the video is not an ad-hominem as it does address the substance of the issue, namely that the "32000 list" is meaningless as the vast majority of the signatories have no relevant expertise. Personally the style is perhaps not my cup of tea, or yours, but as they say "chacun à son goût". It would clearly be unreasonable to require every link to another site posted on SkS to conform to SkS's comments policy. Sadly not all of the useful information out there is conveyed in the generally very restrained manner you find here.

        

       N.B. Moderator trolling comments such as "Will my comment deleted for telling the verifiable truth?" and "delete my comment so that you don't have to face your own contradiction." do you no favours. If you sincerely want to change things, setting out (happily unsuccessfully) to annoy is rarely a good way to achieve your aims.

       ---

       [DB] Additionall, please refrain from the use of all-caps (that Comments Policy thing-y).

83563. trunkmonkey at 03:24 AM on 8 June 2011
       Can we trust climate models?
       Kevin C @79. "To what extent is the response of a GCM constrained by the physics, and to what extent is it constrained by training?" This is exactly the question lurking (even subliminally)in the back of every moderately skeptical mind. I have played with the EDGCM model a bit and it is frustrating to not know what is going on in there. One approach might be to get a list of all the tuned or trained parameters and the values assigned to them (I have never seen such a list)and vary each by an even increment one at a time. Something like this must have been done as the parameters were developed, but with a different objective. To know the answer to your question would be a huge benefit to climate science.
       Moderator Response: [Dikran Marsupial] This sort of sensitivity analysis has been done using a variety of models, for example, see the experiments at climateprediction.net.
83564. dhogaza at 03:19 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       "I would lastly make a purely personal and unscientific observation... I've said it before, that predicting ice is a worthless and tricky game" Scientifically worthless but ... it's an entertaining game, and from the point of view, not worthless at all.
83565. Eric the Red at 03:07 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       Agreed Dana. That is why I refrain from nailing down the sensitivity at 3°C, and do not rule out lower values (I do nto rule out higher values either, but seldom get an arguement on that side).
83566. Daniel Bailey at 02:53 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       The ice is thinner this year, too:

       "The Polar 5 towed the sensor on an 80 metre long rope at a height of 15 metres above the ice surface for the surveys. A preliminary evaluation of the measurement results shows that one-year-old sea ice in the Beaufort Sea (north of Canada/Alaska) is about 20-30 centimetres thinner this year than in the two previous years. In 2009 the ice thickness was 1.7 metres on average, in 2010 1.6 metres and in 2011 around 1.4 metres. "I expect that this thin one-year-old sea ice will not survive the melting period in summer," Dr. Stefan Hendricks assesses the situation. In several weeks his colleagues from the sea ice group at the Alfred Wegener Institute will present their model calculations for the sea ice minimum in 2011, which will also include the data now collected."

       Emphasis added. Given that a typical melt season sees 1.6 to 1.7 meters thickness of melt (FY ice), doesn't bode well at all. Polar bear soup, anyone? ;)
83567. michael sweet at 02:47 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Sphaerica, Thanks for mentioning that site. There wasn't space to mention everything in the main post. The ice flow in camera two has fractured. If you watch for a few days the other side moves. The ice in camera one also seems to have fractured but it is still stuck together. What does it say about the ice at the pole when the thickest ice the researchers could find fractures right next to both cameras? The temperature in the upper corner is the camera temperature, not the outside temperature. Nicholas: Denial Depot is a joke site. I am not sure who posts it. He has some very clever stuff. This is my favorite graph. Some of the posters think he is serious.
83568. Bob Lacatena at 02:47 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       I would lastly make a purely personal and unscientific observation... I've said it before, that predicting ice is a worthless and tricky game, because things change dramatically over night (see last years fast, early rate of melt, which suddenly put on the brakes in July). But with that said, if you look at the ice for 2007, 2008, 2010 and 2011, side by side for the same day, you will see noticeable differences (with the most similarities, surprisingly, in 2008). [Cryosphere today is a good place to do this, but rather than use their "compare" link, go to the archived images with the link in the upper right, and you can pull up larger, more detailed images for past years... FYI, 2010 isn't there, and the links for 2009 don't work, but you can get a 2010 image by clicking the 2009 link, then changing 2009 to 2010 in the url and getting that.] But the key things are that, extent aside, the ice is sparse at all lower latitudes, all the way around. Ice is already gone from places that it never has vanished from this early before, and not just here or there, but all around ... Alaska, and Greenland, and Hudson Bay, and Scandinavia, and Iceland, and... And at the same time, there are patches of not-100% ice in the center of the Arctic, too. It does not look good.
83569. dhogaza at 02:44 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       "That's Neven's Arctic Sea Ice graph page. " Yes, it is, I didn't realize there was no attribution on the page itself, otherwise would've attributed it directly in my tag.
83570. Bob Lacatena at 02:41 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Mods -- I goofed, and left out the closing quotation in my link, so it's messing up the page and mucking up the comment that followed mine. Please fix.
       Response:

       [DB] Way ahead of ya.

83571. Daniel Bailey at 02:39 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       @ Sphaerica (6) We've been discussing that over at Neven's. We're pretty sure it's a lead. Given the melt season yet ahead and the proximity to the lead, the cameras & gear deployed there may be at risk before they are eventually exported out the Fram.
83572. Bob Lacatena at 02:39 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Arctic ROOS is also useful, because it offers a graph of area as well as (and separate from) extent.
       Response:

       [DB] Fixed tag.

83573. Bob Lacatena at 02:37 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       I also look at the DMI Center for Ocean and Ice graph. This one is good because it uses 30% sea ice instead of 15%, like most of the others. I think this is more representative of what is really melting, versus just floating around and re-compacting or dispersing and melting.
83574. Bob Lacatena at 02:35 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       You forgot a great one, for literally watching the ice melt... the North Pole Web Cam. On camera two, you can notice what looks like a melt pool already forming (it seems to have started 5/31 or so). You can also see, on both cameras, the current temperature in the upper left corner. There's loads of other info to be found there, including cool "stop motion" movies from years past.
83575. dana1981 at 02:33 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       I've discussed implications of the instrumental record on climate sensitivity a few times, most recently in Lindzen Illusion #1. Bottom line, it's not far from 3°C, but the aerosol uncertainty complicates things so it's hard to narrow down.
83576. dana1981 at 02:30 AM on 8 June 2011
       Irregular Climate podcast 20: Dead trees make for good reading
       Good show, Dan. I particularly liked the discussions of renewable baseload energy and the true cost of coal. That's right up my alley :-)
83577. Tom Curtis at 02:22 AM on 8 June 2011
       There's no correlation between CO2 and temperature
       J Bob @13: 1) There has been an increase of CO2 from 285 to 390 ppm since 1850, or 37%. Over the same period the forcing from CO2 has increased from approximately 30 W/m^2 to 31.7 W/m^2, or 5.7%. Running a direct comparison between CO2 and temperature therefore significantly distorts expectations of the effect of CO2 forcing. Your insistence on making a comparison known to be misleading rather than one known to be accurate is not a problem with my argument. Rather, it is a problem with your credibility. 2) Comparison of estimated forcings for all well mixed Green House Gases (second column) compared to the direct and indirect aerosol effect (second last and last columns respectively) show that until about 1950 they are always close to balancing each other out. Occasions when they are not quite in balance either coincide with exceptionally cool periods when the aerosol forcing is stronger (1910), or rapid warming when the GHG forcing is stronger (late 30's). After 1950, and particularly after the mid-1970's, GHG forcings begin to exceed aerosol forcings on a consistent basis. 3) Talking about just CO2 forcings is, once again, a futile exercise. It is like trying to predict how long it takes for a feather to fall from the Tower of Pisa using Newton's laws of motion and gravity alone. Including the effect of anthropogenic aerosols results in a good match to the various temperature fluctuations. It would be an even better match if we have been underestimating their effect as recently suggested by Hansen 4) Long lived components of the atmosphere like GHGs are well mixed between SH and NH. Short lived components like aerosols are not. Consequently the SH has a similar GHG forcing to the NH, but a much reduced aerosol forcing. It therefore provides a natural experiment which better quantifies the effect of CO2 forcings. That is straight forward enough. That you prefer a temperature record where we expect a maximum contaminating effect from aerosols (Europe) and at the same time refuse to factor in aerosol forcings into your calculation is very telling.
83578. Eric the Red at 02:16 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       True, but the instrument record showed a similar sensitivity with higher confidence than other methods.
83579. Rob Honeycutt at 02:15 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       I often wonder if Arctic Sea Ice is going to be the canary in the coal mine that will really start to wake the general public to what is actually going on with the climate.
83580. dhogaza at 02:01 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Here's pretty much everything you'd ever want on one page.
       Response:

       [DB] That's Neven's Arctic Sea Ice graph page.  Good bringing it up, though.

83581. dhogaza at 02:00 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       

       Please tell me that is a (quite funny) joke....

       I'd tell you, but then I'd have to kill you. Get it? :) :) )
       Response:

       [DB] Keeping up with the Groanses?  This one's for you...

83582. dana1981 at 01:49 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric #12 - the Knutti and Hegerl figure shows a large range of possible values for the past millenium. You'll note it also shows a smaller range for the 'current mean climate state', with a most likely value of 3°C.
83583. J. Bob at 01:38 AM on 8 June 2011
       There's no correlation between CO2 and temperature
       Tom Curtis @ 11, your 4 point argument has a few problems. 1-Nothing was stated about linear correlation, or linkage between CO2 & global temperature being linear. And if you have ever worked on non-linear systems, most do respond to input changes, such as aircraft stall, or even ferrous transformer cores (except in full saturation). 2-So why was CO2 not considered a dominant factor prior to 1950? Seems to be a giant leap of faith, like in 1950, CO2 woke up. Although it’s a convenient point, since global temperature was bottoming out from the 1942-1955 ~0.45 deg. C (HadCRUT3gl) dip. 3-Even the Krakatau eruption in 1883 didn’t seem to phase the global temperature, with all the material dumped into the atmosphere, nor did it seem to effect the Lawdome CO2 data. Nor did CO2 change during in the 1880-1910 (HadCRUT3gl) 0.5 deg. C dip, or the longer 1775-1860 (Ave14). 4-I looked at NH data, since that is where most of the long term temperature data sets reside. As far as gases mixing, I assume the gas diffusion law still works between the NH & SH, so CO2 distribution should be pretty uniform globally. The one area we might agree on would be the increase in particulates in the atmosphere, such as the Asian Brown Cloud. http://www.imagenerd.com/uploads/co2_temp_1650-2010_440-FGyPh.gif Here is a higher resolution graph. http://www.imagenerd.com/show.php?_img=co2_temp_1650-2010-NZ4UP.gif
83584. Nicholas Berini at 01:37 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Was the figure at the bottom actually ever presented that way? Please tell me that is a (quite funny) joke....
83585. Eric the Red at 01:37 AM on 8 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Another site of interest is the Danish Meterological Institute http://ocean.dmi.dk/arctic/icecover.uk.php
83586. Eric the Red at 01:32 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       #11: See graph above from Knutti and Hegerl.
83587. Dikran Marsupial at 01:31 AM on 8 June 2011
       Can we trust climate models?
       Riccardo I am not against testing the accuracy of GCMs on a decadal timescale, especially as the modellers seem to feel this is becoming a worthwhile activity (judging from the references given). The problem is that the F&K paper if anything sets progress back by use of bogus statistical procedures and lack of understanding of GCMs. Even their combination of statistical models and GCMs is invalid because they optimise the combinations on the test data and perform a multitude of experiments without taking into account the fact they are doing multiple hypothesis tests. The conclusions seems to be an alternation of overstatement and caveats. This is not the way to do science, do the experiment right and then report the results. If you can't draw a conclusions without caveats that effectively make the conclusion invalid, don't draw it in the first place. The paper suggests decadal predictions will be in th enext IPCC report, I expect they will get the experiments basically right, better to wait for that IMHO.
83588. Riccardo at 01:17 AM on 8 June 2011
       Can we trust climate models?
       Dikran you're absolutely right on this last point, it doesn't makes much sense to compare GCM with station data. I also agree that they overstate their conclusions and that the IPCC shouldn't be mentioned at all. Probably they are new in the field of climate and slipped badly on this. But let me go back to my original point. I didn't mean that this paper has any particular value; though, it address a point that might be relevant when people try to study the possibility of medium term projections. We all know that GCM are not designed to do this and that they need some new idea to perform this task. F&K idea is not new, right, and not the only one. But I didn't see it applied to decadal projections. I think it's worth a try and in doing this I wouldn't be surprised if we learn something on the short/medium term behaviour of the climate system.
83589. Robert Murphy at 01:09 AM on 8 June 2011
       Tony Abbott denies climate change and advocates carbon tax in the same breath
       To be fair to Abbott, who is otherwise clueless about climate change, *he* wasn't proposing a carbon tax in that clip. He was saying that *if* you accept AGW and the need to reduce CO2 emissions dramatically, a carbon tax is better than an emissions trading scheme. He says that immediately after the above clip ends. "Yesterday morning, I uploaded the one minute answer onto YouTube:" It wasn't one minute, he spoke for almost 30 more seconds answering the climate question. In reality, since he doesn't accept AGW as a problem, he's against the emissions trading *and* the carbon tax. Again, he's completely wrong on the science of climate change, but this clip is not evidence of him damning the science on one hand and then on the other hand calling for a carbon tax to reduce emissions when he doesn't think emissions are a problem anyway.
83590. sime at 01:07 AM on 8 June 2011
       Tony Abbott denies climate change and advocates carbon tax in the same breath
       Riccardo@2 they do indeed but... The... "not enough evidence" line is really starting to get nauseous, do Abbott and the rest of these individuals phone up their insurance companies demanding proof that their house is going to burn down or that their car is going to be involved in an accident before they will pay their insurance premiums?
83591. Gregory D. MELLOTT at 01:01 AM on 8 June 2011
       CO2 lags temperature
       One clearly can see in the backside of the direct corrolation between CO2 and temperature, that the CO2 is too high to match. If one seperates the GHGs and notes three basic facts about methane-ice then it can explain alot about why the simple CO2 corrolation is off. One fact is that methane is about 50 times stronger as a GHG than CO2. The second is that it turns into CO2, over time, as it is oxidized. The last fact is that it takes a long time for methane-ice to build up (persisting when the environment is colder). A guess is that it may take 20 to 50 thousand years of cool times for it to become a signicant factor again, once it is released. Noting these points one can then shift the alignent for CO2 down and add the methane-ice release effect on top of it in the initial phases of warming after cooler periods. As for the simple effect of methane released by life forms, it may be a small factor; yet I suspect it pales in comparison to the huge amounts released by the thousands of years of bacteria production in the whole of the earth soils being released over a short period of time.
83592. actually thoughtful at 00:55 AM on 8 June 2011
       Are you a genuine skeptic or a climate denier?
       Eric (Skeptic) "Millions of people on the deltas will need to be moved and compensated for losses, but that will be relatively cheap compared to 100 years of cheaper power in the developed world." That statement strikes me as incorrect. Many threads on Skeptical Science show that renewable energy is relatively cheap (and my own work in the field verifies it). I believe the "millions" can only count the US, and it will be billions (note the consonant) that will need to be relocated. The whole point of talking about AGW (once you study the science) is to prevent it. And of course, your points only relate to the physical location of people and things, not the fact that a warmer world is a natural-services poorer world (ie food and potable water are harder to come by).
83593. skywatcher at 00:51 AM on 8 June 2011
       Christy Crock #6: Climate Sensitivity
       #9: why would equilibrium sensitivity be lowest during the past 1000 years? Do you have a source for that statement? With easily changeable sea ice areas, the climate of the past 1000 years has a demonstrably substantial sensitivity, as we are proving now (~0.8C transient change for ~35% Co2 increase, so ECS 3C or more per doubling when slow feedbacks have operated). A climate without significant Arctic sea ice would likely have a slightly lower sensitivity that our present climate, as there would be less scope for albedo feedbacks. #10: You mis-interpret. Equilibrium sensitivity is not affected by events as transient as individual solar cycles or ENSO. It is the aggregated effect once slow feedbacks have had time to operate.
83594. Dikran Marsupial at 00:49 AM on 8 June 2011
       Can we trust climate models?
       Section 3.3 of the F&K paper shows they definitely have no idea about the way in which GCMs are used. They try to use GCMs to predict station data, which obviously is a non-starter. The climate at particular stations depends a lot on the local geography (compare rainfall in Manchester and York for example), where as the value for the nearest gridbox in a GCM is an area average over a very large area. For that very reason impacts studies use statistical downscaling methods that aim to predict local (station level) data from the GCM output for nearby grid boxes (e.g. European scale). Does this get a mention in the paper? No. The reason is because they are basing their work on one paper by Koutsoyiannis et al, which was subject to those same criticisms over at RealClimate.
83595. Dikran Marsupial at 00:31 AM on 8 June 2011
       Can we trust climate models?
       The more I read this paper, the more surprised I am that it made it through review. There are five steps listed in the description of the GCM system (DePreSys); however in the evaluation F&K only use the first four, but admit that the fifth step gives an improvement in performance. In otherwords, the GCM is only allowed into the fight with one arm tied behind its back. If I were a reviewer I would not have recommended this paper be published unless a fair comparison were performed with the GCM used in accordance with the makers instructions. It may be true that would limit the prediction horizon to nine years rather than ten, but that is far less of a problem than using an incorrect implementation of the GCM based method.
83596. John Hartz at 00:22 AM on 8 June 2011
       Can we trust climate models?
       "Diffenbaugh and Scherer analyzed more than 50 climate model experiment and found that large areas of Earth could experience a permanent increase in seasonal temperatures within only 60 years. Their analysis included computer simulations of the 21st century when global greenhouse gas concentrations are expected to increase, and simulations of the 20th century that accurately “predicted” the Earth’s climate during the last 50 years." Source: "Stanford Climate Scientists Forecast Hotter Years Ahead", Planetsave (http://s.tt/12BR7) http://s.tt/12BR7
83597. Eric (skeptic) at 23:59 PM on 7 June 2011
       Are you a genuine skeptic or a climate denier?
       scaddenp, I believe nuclear will be cheaper under the conditions I specified above: that private insurance companies enforce safety and the government enforces measurement and payments for injury (rational payments based on statistical cancer risks). Your other point, that coal is cheap, is valid. People didn't like my Rube Goldberg idea for cutting travel fuel in half and they probably won't like my cut electricity in half ideas either. But since my early posts here I have supported the smart grid and that would greatly smooth out the expensive peaks. But that still leaves cheap coal baseload production. Addressing the externalities, we need to be more precise about the costs. Droughts, floods, heat waves, and other weather need to be costed with regard to their natural variations. Sea level is easier since it isn't weather, so let's pick that. It will cost you a new airport. The late Senator Byrd would literally move a mountain, fill in a valley and get you a new high elevation airport (see route 55 in WV). Millions of people on the deltas will need to be moved and compensated for losses, but that will be relatively cheap compared to 100 years of cheaper power in the developed world. The actual number of years will be a lot less with technological progress. The doomsday scenarios ignore facts (e.g. calthrates don't melt in the Gulf of Mexico and won't melt in the Arctic below the same or higher levels). We can argue these details on other threads, but my point is that the external costs need to be realistic otherwise it will be a nonstarter academic exercise.
83598. jyyh at 23:11 PM on 7 June 2011
       Poleward motion of storm tracks
       Some more talk of other recent papers at http://rabett.blogspot.com/2011/06/eli-is-evil-bunny.html , maybe relevant to this, or, the whole atmospheric circulation.
83599. Dikran Marsupial at 23:07 PM on 7 June 2011
       Can we trust climate models?
       Riccardo I don't think this paper sheds much light on the limitations of GCMs (especially ensembles of GCMs). As I said, GCMs only aim to predict forced climate change, so it shouldn't be a surprise to anyone that a statistical forcasting model that is directly aiming to predict the observed climate is more accurate. They haven't mentioned this point as far as page 10, perhaps the do afterwards. They provide very little justification for decadal timescales as those relevant to policymaking. As they say that the IPCC are more interested in long term centenial timescales, one wonders why they mention the IPCC so often in the report given that the IPCC policy guidance is based on centenial timescales not decadal ones (and thus their paper is only of tangential relevance). Their idea about reinitialising the GCMs is basically what is done in reanalysis, so it is hardly new. The paper also hints that is what is done in the Mochizuki paper anyway (but one paper at a time! ;o) I like the analagy, similarly why would F&K (or any skeptics) expect the sprinter to win the marathon? Statistical methods working well on decadal predictions does not mean they are more accurate on centenial scales. As a statistician myself, I would much rather extrapolate using a physics based model than a purely statistcal model (and a neural network is pretty much the last statistical model I would use). An interesting experiment would be to see how statistical methods fare in predicting the output of individual model runs (treating the model as statistically exchangeable with the real world) on both decadal and centennial scales. I suspect the models perform better on centennial scales (as they are designed to do), even if the model used for prediction is not the same model used for generating the synthetic observations. It would at least be a sanity check of their conclusions.
83600. Tom Curtis at 23:07 PM on 7 June 2011
       Tony Abbott denies climate change and advocates carbon tax in the same breath
       What strikes me about his taxation scheme is the complete futility of it. It is a common denier myth that at tax and dividend scheme as proposed by Hansen, and such as Australia may soon get a hybrid version of that it will be ineffective because the consumers will receive back all the extra money they pay in carbon tax, so there will be no net incentive to change behaviour. This is false in that the dividend it not tied to the effective carbon emissions of the consumers. By sourcing electricity from low carbon sources, or using it more efficiently, they can reduce the amount of carbon tax they pay while not reducing their dividend. That creates a clear incentive to reduce carbon emissions. In contrast to Hansen's scheme, however, Abbot proposes that at the end of each year you would be able to get "... a rebate of the tax you paid". (45 seconds in) In other words, your rebate would equal the carbon tax paid during the year. If you reduce your carbon emissions, and therefore the tax paid, you equally reduce your rebate. Consequently there is only minimal incentive to reduce your carbon emissions. The small remaining incentive is in the delay between paying the carbon tax and receiving your rebate, a period during which you are effectively paying the government a forced interest free loan. The effective Carbon tax on Abbot's scheme reduces effectively to the interest rate on the nominal tax rate, or typically about one twentieth of the nominal rate. The administrative costs would, however, be a function of the nominal rate, making this an incredibly burdensome and inefficient, not to mention ineffective tax. I must emphasise that none of these points are valid criticisms of genuine tax and dividend schemes in which the dividend paid is independent of carbon emissions.

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