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Ken Lambert at 20:26 PM on 2 May 2010Tracking the energy from global warming
Chris #97,98 You have the raw data - why don't you settle this by doing a curve fit - least squares should do so that we can see the continuous trends instead of picking average end points and drawing straight lines. Before you do so - here are some comparisons: The CSIRO paper by Domingues et al..comes up with a global average sea level rise of 1.6+/-0.2mm (published 2008) viz: http://www.nature.com/nature/journal/v453/n7198/abs/nature07080.html Dr Trenberth uses an ‘observed’ number of 2.5mm in his energy budget calculations made up of components with wide error bars eg. 0.8 +/-0.8mm. Both the above are well below the average 3.2mm of Chris’ graph. The CSIRO quotes the satellite sea level figures with error bars of +/-5mm. -
HumanityRules at 17:03 PM on 2 May 2010What causes Arctic amplification?
3.Steve L I don't get it either. Most of it seems counter-intuitive to my simple mind! The paper may be useful for ruling out some possible causes but does it do anything more than show an apparent relationship for one decade between sea ice and temperature, where is the cause and effect? Lupkes, C., T. Vihma, E. Jakobson, G. Konig-Langlo, and A. Tetzlaff (2010), Meteorological observations from ship cruises during summer to the central Arctic: A comparison with reanalysis data,Geophys. Res. Lett., doi:10.1029/2010GL042724, in press. This paper in press at GRL questions the accuracy of the ERA reanalysis compared to some ship based observations. -
Steve L at 15:05 PM on 2 May 2010What causes Arctic amplification?
I'm afraid I don't really get it. As usual I'm commenting before reading the full paper. But I did scan it and read this: "The interaction is undoubtedly two-way because warmer upper-ocean temperatures will further enhance sea ice loss." I think it's nice that Screen & Simmonds find evidence against the amplification resulting from upper atmospheric effects. I don't really know how they can focus on diminishing sea ice, though. Doesn't diminishing sea ice rely on Arctic amplification too? The abstract includes changes to ocean circulation in its list of underlying causes of Arctic amplification, and a quick perusal doesn't show me how the patterns they observed are more consistent with sea ice loss than with oceanic currents. Oh well, the paper is short enough -- maybe I'll read it tomorrow. -
Jeff Freymueller at 14:16 PM on 2 May 2010What causes Arctic amplification?
That's interesting. Here in Alaska the pattern of modest summer warming and significant winter warming applies even along much of the Pacific coast, where sea ice is not found. So perhaps the impact of sea ice changes extend out into the sub-Arctic as well. -
Tony O at 11:00 AM on 2 May 2010What causes Arctic amplification?
Given the accuracy of the predictions I would have thought that the process of Arctic Amplification was well understood. Then again the climate is so very complex that further study is always a good idea. -
suibhne at 08:29 AM on 2 May 2010Where is global warming going?
doug_bostrom I don't believe in the necessity of the notion of radiative equilibrium? We will ignore for the moment the fact that radiant energy can be transformed into other energy forms. If the Earth gains more radiation than it loses, its temperature will increase very slowly, see post 55. Likewise if the Earth loses more radiation than it gains, its temperature will decrease slowly. -
Tom Dayton at 08:27 AM on 2 May 2010CO2 effect is saturated
qball17, please refrain from nitpicking, and refrain from using over-the-top terms such as "ridiculous." You might also read more carefully, and when something doesn't make sense, consider the hypothesis that you might not be parsing it correctly; the title is "Is the CO2 Effect Saturated?," which to most readers parses correctly as "Is the CO2-Effect Saturated?" As for Scafetta, scroll down to the link to his paper in this post: It’s the sun. -
Tom Dayton at 08:19 AM on 2 May 2010CO2 lags temperature
qball17, positive feedbacks need not run away, as you can see for yourself in a spreadsheet by following my instructions in my comment on another thread. -
Doug Bostrom at 04:36 AM on 2 May 2010Where is global warming going?
Suibhne, you understand that Earth must lose energy somehow and that it appears it does so by radiative emissions but at the same time you don't believe in the notion of radiative equilibrium? Surely you'll want to qualify that remark? If the Earth is not shedding energy roughly as fast as it gains energy, surely we would expect some change in temperature here at the surface? -
pdjakow at 02:38 AM on 2 May 2010What would happen if the sun fell to Maunder Minimum levels?
@Berényi Péter "Unfortunately GHCN is dominated by USHCN stations. There is no legitimate reason it should be this way. Except it was created in America, by Americans, for Amaricans perhaps. Rather silly explanation." So what? Global anomalies are gridded. First you must calculate anomalies for each station. Then put anomalies on grid. You can also run ccc-gistemp: http://clearclimatecode.org/ You can play with the code, you can play with settings. ccc results and my results calculated on CRU database much differ from yours. And how is it possible that your anomalies are almost always below zero? What is your base period? -
chris at 01:18 AM on 2 May 2010Tracking the energy from global warming
Ken's insinuation of an offset in the Jason satellite altimetry data relative to the Topex/Poseidon altimetry data is interesting, especially since it's rather obvious by inspection of the sea level graphs (see my post #76) and the raw data (see link in my post #76) that there isn't an offset. It's worth looking at the methods by which the Topex/Poseidon and Jason satellite altimetry data was merged into a continuous record of sea level rise [***]. This also helps us to understand that an offset of the sort that Ken is hunting for is both methodologically unlikely, and also doesn't in reality, exist. Three things were done to ensure a relatively "seamless" transition: (ONE) In the transition period (15 January through 15 August 2002), the Jason and Topex/Poseidon satellites flew in formation along the same ground-track, separated in time by only about 70 seconds. Thus they collected virtually identical data for a 6 month period, and this was used to intercalibrate the altimeters and verify that the data were correctly merged in the transition period. (TWO) Although Topex data is often not presented after 2002, data was collected from Topex (the Topex B altimeter) at least through 2004. The Topex B data match with the combined Topax A/B set and with the Jason altimeter set. (THREE) During the Topex and Jason missions the satellite data is continually calibrated against the sea-level tide guage sea level measures. While tide guage measures don't provide an absolue measure of global sea level, they are effective in identifying any step changes (of the sort that you infer from your regressions). There aren't any in the Topex-Jason transition period. ---------------------------- [***] Beckley, B. D. et al. (2004) Towards a seamless transition from TOPEX/POSEIDON to Jason-1 Marine Geodesy, 27, 373-389 link to abstract E. W. Leuliette et al. (2004) Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change Marine Geodesy 27, 79 — 94 manuscript available here Beckley, B. D. et al. (2007) A reassessment of global and regional mean sea level trends from TOPEX and Jason-1 altimetry based on revised reference frame and orbits Geophys. Res. Lett., 34, L14608 link to abstract -
Tom Dayton at 01:12 AM on 2 May 2010Common graphical tricks and the Medieval Warm Period
alphaomega, the breadth of your comments makes me think you would benefit from and enjoy reading the overview by cce titled The Global Warming Debate. I suggest you read that before diving into the details that are in the following links. alphaomega wrote the following italicized and quoted things. For each, I've responded by linking to the appropriate post here on the Skeptical Science site. alphaomega, if you want to discuss any of those topics, those threads are the appropriate places to do so. Not on this thread, where your comments likely will be deleted for being off topic. "Dr Jones admitted in a recent BBC interview that there has been a slight cooling since 2002 and statically not significant warming since 1995." See Phil Jones says no global warming since 1995. Also see It’s cooling. "So we are on a current temperature downturn and the sun is still quiet. Is it actually possible that we might return to Maunder minimum terrritory instead?" See We’re heading into an ice age. "I do not think that AGW supporters or sceptics really know what will happen next to global temperatures." See Models are unreliable. "There may be a week warming signal caused by CO2 but natural variations in climate have the ability to overpower such a signal." See Models are unreliable. Also see CO2 is not the only driver of climate. And then CO2 effect is weak. "It is worth while reading the recent interview with Dr. Fred Goldbereg." (This one is not a post on Skeptical Science.) Goldberg is not a climatologist. His expertise is in welding. -
chris at 00:47 AM on 2 May 2010Tracking the energy from global warming
Ken Lambert at 21:12 PM on 1 May, 2010 Ken, am I right in thinking this is what you've done: a. taken 7 years of the Jason data (2003-2010?; did you use the raw archived data or eyeball the plot in my post #76?)). b. done a regression and determined the slope (you've chosen a subset that apparently gives you 1.7 mm.yr-1; if you use the full Jason data set available from the link in my post #76, the linear regression is 2.3 mm.yr-1). c. used the regression fit and extrapolated this back to 2002 (+12 mm) and forward to 2010 (+26). Is that what you did? Perhaps you could clarify. Whatever, I hope you would recognise that that's a bogus analysis. One can't use a regresssion, and then assert that particular points on the regression (e.g. the start or end points) are the data. The data are shown in my post #76, and the Jason data clearly doesn't start at +12 mm (nor does it end at +26 mm). There clearly isn't an offset with respect to the Topex data. That's also apparent by inspection of the other data sets (with/without seasonal adjustment; with/without reverse barometer correction) available from the link in my post #76. -
alphaomega at 00:01 AM on 2 May 2010Common graphical tricks and the Medieval Warm Period
SNRatio wrote 30 April "With ca 0.15 degC warming/decade, it will just take a few decades for us to leave MWP territory altogether." Dr Jones admitted in a recent BBC interview that there has been a slight cooling since 2002 and statically not significant warming since 1995 (I seem to recall). So we are on a current temperature downturn and the sun is still quiet. Is it actually possible that we might return to Maunder minimum terrritory instead? As an interested retired businessman I read both sides of the arguments and frankly I do not think that AGW supporters or sceptics really know what will happen next to global temperatures. I must admit I tend to lean towards the views held by such individuals as Dr Roy Spencer and Professor Lindzen that there may be a week warming signal caused by CO2 but natural variations in climate have the ability to overpower such a signal. For those believing that CO2 has this strong influence on global temperatures it is worth while reading the recent interview with Dr. Fred Goldbereg in People's Daily. http://english.people.com.cn/90001/90777/90853/6959757.html Frankly there seems to be a long way to go before the climate science community know enough to exhort us to pull up the wallet and deliver billions of dollars to "saving the World". Just think of the AGW understanding of the behaviour of clouds and the lack of modelling of this behaviour in current climate models. -
kdkd at 23:07 PM on 1 May 2010Tracking the energy from global warming
Ken #94I get two distinct linear trend lines from the sea level graph.
I think that's your imagination but would stand corrected if you demonstrated otherwise objectively. However my experience of graphs that look like that is that there's generally no significant difference between the regression slope at different points of the time series - the internal variability of the system is just too high. -
Ken Lambert at 21:29 PM on 1 May 2010Tracking the energy from global warming
Sphaerica #93 From what I have read, lakes of water have been discovered under the ice sheet trapped between it and the bedrock. I believe that at these extreme pressures ice can transition to supercooled water. If that pressure was removed by leakage, the supercooled water would change back to ice at well below zero temperatures. On the other hand, Ice is also a very good insulator, so across its depth, it could sustain a temperature differential. How this would work with an under ice volcano or a geothermal heat source would be interesting. -
Ken Lambert at 21:12 PM on 1 May 2010Tracking the energy from global warming
Riccardo #91 I get two distinct linear trend lines rom the sea level graph. Topex from about -24mm up to +6mm over about 9 years giving about 3.3mm/year; and Jason from about +12 to +26mm over 7 years giving about 1.7mm/year from about 2002-03 onward. This seems to indicate about a +6mm jump in the 2002-03 transition period. On these very roughly cyclical charts it seems odd that the mid point of the end of Topex would match up with the low point of the Jason plot at the transition. Would also like to know if the IBP corrected global charts are much different from this non-corrected chart. -
qball17 at 20:41 PM on 1 May 2010CO2 effect is saturated
you should have a look at the following link and see what you think.. http://miskolczi.webs.com/Answers_to_some_criticism.htm it also has a link to his 2004 paper which people don't look at, that is why they get confused and see his paper as making too many assumptions etc.. its because 2007 paper is the sequel to his 2004 paper where he defines many of his terms and comes up with the science behind the theory -
qball17 at 19:18 PM on 1 May 2010CO2 effect is saturated
and another thing.. he did publish it in hungary. Dr. Miskolczi first published his work in the Quarterly Journal of the Hungarian Meteorological Services in 2004, Volume 108, No 4. He published further statistical proof in the same Journal in 2007, Volume 111, No. 1. In the 5 years since he first published his results, not one peer review has come back disproving his theory, or his Constant. To date, not one scientist has come forward to disprove Miskolczi’s theory that the Earth’s climate is at equilibrium, and that Carbon Dioxide cannot be released in amounts great enough to upset that equilibrium. -
qball17 at 19:16 PM on 1 May 2010CO2 lags temperature
hang on a sec.. they claim that temperature drives CO2 levels, but then the rising C02 drives the temperature even further... then why is it that we aren't all living in 10000 degree temperatures? oh thats right i almost forgot.... the earth has a saturated greenhouse effect... think about it.. the earth has to have a saturation point -
Marcel Bökstedt at 19:09 PM on 1 May 2010Why are there fewer weather stations and what's the effect?
Berényi Péter> Actually, I don't find your result on the populations A and B very surprising. If we suppose that these stations have some natural variations, the elements of group B will at the time +20 years be more likely to be in a state of positive natural variation than the elements of group A. So when this natural variation on average falls back to normal (in the period between +20 and +40), this will give a negative contribution to the trend. It would be interesting to compare the trends of A and B through the whole interval (not just for the last 20 years). My prediction is that then the trend for B would be equal to or slightly more positive than the trend for group A. I'm sure that you can do this computer experiment with a few clicks, now that you have enetered all the data? But I absolutely agree with you that we should try to get as much data as possible. -
qball17 at 19:08 PM on 1 May 2010CO2 effect is saturated
and by the way.. the title of this topic is ridiculous.. its not the "saturated Co2 effect", its the "saturated GREENHOUSE effect".. we all know that we can increase the concentration of CO2.. what about the work from Dr. Nicola Scafetta? -
qball17 at 19:02 PM on 1 May 2010CO2 effect is saturated
the reason why he couldn't publish it was because NASA refused to let him, so then he went back to hungary and made his paper.. just like all the other scientists who say how hard it is to get a scientific journal published that is against or is skeptical about anthropogenic climate change. Don't you find it funny how all the readily available journals are CO2 CO2 CO2.. how can science come up with such a definite conclusion with all the other factors that would contribute.. this issue has turned into a political one, not scientific... how do these papers justify the CO2 lag behind temperature, and solar activity etc etc -
Marcel Bökstedt at 17:51 PM on 1 May 2010Common graphical tricks and the Medieval Warm Period
HumanityRules> Even if I'm not completely sure what they do mean with the expression, I assume that "mostly warmer than the 1901-1995 climatology" means something like "warmer than the average temperature in the period 1901-1995". But because of global warming it is now warmer than the 20 century average, and the diagrams of the paper do suggest that the temperature in the middle ages might have been lower than the temperature today. -
Berényi Péter at 17:43 PM on 1 May 2010Why are there fewer weather stations and what's the effect?
#28 Oxford Kevin at 08:23 AM on 1 May, 2010 It will be interesting to see the discussion Thanks for the links, I'll look into them. However, to make it clear, I don't claim they have made an error in their calculations. Just have asked the same wrong question. Anyway, I'd prefer to have this result checked and double checked first. It is not too difficult, in a technical sense. There are tens of thousands of guys out there with the proper skills to do that. Also, as I have said, there is a vast amount of fresh data online. Just takes time to collect it. I really don't understand why it has not been done long ago. It seems to be a bit reckless to base a multi billion dollar trade like carbon credits (with plenty of room for fraud) on deficient data. It simply makes more sense to do the job right away than trying to explain why it does not need to be done. -
Jeff Freymueller at 14:30 PM on 1 May 2010Common graphical tricks and the Medieval Warm Period
#53 HumanityRules, we might disagree whether McIntyre a politically motivated or not, but even if you think he is not, there have been plenty of attacks that clearly are. For example, several years ago Rep. Joe Barton sent out letters demanding all sorts of material from Mann's employer, and the new and very radical right-winger Attorney General of Virginia has just done the same (Mann used to work at the U. of Virginia). Then there are all the blogosphere attacks on top of that. But you asked about McIntyre's criticism. The first I had heard of this whole issue was in 2005 when McIntyre and McKitrick had a paper published in Geophysical Research Letters that suggested an artificial hockey stick-like shape could be introduced by a feature of the Principal Component Analysis that Mann et al. used. But there were two comments published on the paper (I thought I remembered a third, but I can't find it). M&M had replies to the comments but I found the replies to be weak, and I think the comments were on the mark. The comments both showed that while Mann et al were technically in error in their application of PCA, the error actually had little impact on the results. In fact, the analysis was later redone with the error corrected, and this was shown to be true -- the error had little impact. I found freely downloadable PDFs of the comments, links below (not sure about the replies). Von Storch and Zorita used climate models to generate a synthetic set of proxy data that they analyzed with the original and corrected method. The difference was not significant. Huybers showed that the reason M&M found a significant artificial hockey stick effect was that M&M themselves made a statistical error. Their Monte Carlo simulation were not adjusted to match the variance of the instrumental record. This led them to significantly overestimate the reduction of error statistic, and led to an exaggerated artificial hockey stick effect relative to the actual Mann et al. method. When Huybers corrected this error by M&M, the M&M code gave results very similar to Mann et al. Bottom line: yes, there was an error in the original 1998 paper, but it made almost no difference to the result. McIntyre claimed it made a big difference, but only because his own approach was in error and exaggerated the effect. The error has long since beeen corrected. There has also been a vigorous scientific debate about that 1998 paper, and in the whole field, and of course today the work being done has advanced quite a ways since then (improved methods, more data). But the result is still standing. -
HumanityRules at 13:19 PM on 1 May 2010Common graphical tricks and the Medieval Warm Period
45.Jeff Freymueller You can put me straight on this as I haven't followed the history but my understanding is that the attack on the Hockey Stick was originally a scientific one. McIntyre and others have questioned the validity of either the statistics and/or the appropriateness of the series used. From my understanding this critisism is completely rejected by Mann and other pro-warmers, the fact that these critisisms do not seem to shape IPCC is worrying. 47.Marcel Bökstedt Sorry for my lack of accuracy but you'll have to explain to me how "mostly above the 1901–1995 climatology" is substantively different to "as warm as now"? Of the 6 SH proxies used by Mann 2009 to prove the whole of the SH did not participate in medievel warming 3 are located in the tropics and 2 of them are sediment record. Using your criteria we are down to 3 proxies in the SH (Tasmania, New Zealand and Southern Africa) which prove there was no global MWP! The IPCC uses the Hockey Stick by to say that the present climate conditions are unique compared to the rest of the last 2 millenia, and that this must be due to anthropogenics CO2. My argument would be that there are sufficient proxies that put the present conditions at the top end of the range of natural variation. -
CO2 at 13:01 PM on 1 May 2010Has Arctic sea ice returned to normal?
I agree with Carlos #1. Just checking my spreadsheet for ice melt 2010. In 2009 the max extent was 14.41 million sq/km on March 5. The 2010 extent on the same day was 14.31 m/sq/km. The 2010 max came late on 31 March, identical to 2009 at 14.41 m/sq/km. On that date the 2009 extent had dropped to 13.97 m/sq/km which gave 2009 a head start of 440,000 sq/km. Since March 31 2010 the drop in extent was 1.24 m/sq/km at a rate of 41,297 sq/km per day. For the same period in 2009 the drop in extent was 803,438 sq/km at a rate of 26,781 per day. This is a good indicator that late thin ice melts rapidly. The sea ice extent on April 30 is now the same for 2009 and 2010 at 13.16 m/sq/km. -
HumanityRules at 12:40 PM on 1 May 2010Skeptical Science talk at University of Qld on May 7
GL -
Philippe Chantreau at 12:18 PM on 1 May 2010Skeptical Science talk at University of Qld on May 7
RSVP at 12. You're right, all these trees in British Columbia are packing up and walking up North to escape the Pine Beetle... -
CoalGeologist at 09:50 AM on 1 May 2010Skeptical Science talk at University of Qld on May 7
Just returned home today to Dallas--site of the evil "Grassy Knoll"--and thought I'd check if Brisbane, could possibly be at our antipode, and the site of a "good" Grassy Knoll on the other side of the world. But alas, Dallas's antipode is out in the Indian Ocean, somewhere between Perth and Madigascar, and Brisbane's is in the Atlantic, in the general vicinity of the Canary Islands. So there's no cosmic symmetry there! Nevertheless, I've notified my favorite (er, favourite) UQ faculty member of the event, and hope you get lots of geologists in attendance. Break a leg! -
Alexandre at 09:50 AM on 1 May 2010Skeptical Science talk at University of Qld on May 7
RSVP #12 We know Nature can cope with global temperature changes at the rate of some 6ºC in 6,000 years. That's a fast change, like the deglaciation. 3 or more degrees in a century is quite a different challenge. And I'm being conservative. It really outpaces the moving capabilities of many species. Even some animal species have trouble shifting polewards 6.1 Km/year. And remember we humans are here this time to fragment most ecosystems, so it's not like a species can roam freely towards the pole without tripping in a city or farm or National Park limit. -
ktam at 08:23 AM on 1 May 2010Why are there fewer weather stations and what's the effect?
Berényi Since you consider what Tamino has done is meaningless. Have you taken it up with Tamino. Since Zeke, Nick Stokes, Jeff Id, CCC seem to have replicated much of what Tamino has done plus one of them has extended the analysis to produce a global land/ocean temperature reconstruction have you taken this issue up with those who have the tools and experience/background to interpret your results. http://rankexploits.com/musings/2010/comparing-global-land-temperature-reconstructions/ http://rankexploits.com/musings/2010/comparing-global-land-temperature-reconstructions/ http://moyhu.blogspot.com/2010/04/incorporating-sst-and-landocean-models.html http://clearclimatecode.org/ http://residualanalysis.blogspot.com/2010/03/ghcn-processor-11.html http://tamino.wordpress.com/2010/03/05/global-update/ It will be interesting to see the discussion where those who have the statistical background and knowledge of the temperature data to interpret your results. Kevin -
suibhne at 07:46 AM on 1 May 2010Where is global warming going?
doug_bostrom By longwave em radiation -
RSVP at 07:10 AM on 1 May 2010Skeptical Science talk at University of Qld on May 7
John Russel "too fast for most plants and animals to move" Humans were nomads way before they settled down and fenced in their properties and animals migrated as needed (now they get squashed on highways). Point is, the only problem with global warming is that the status quo is finally threatening itself. Nature is equipped for global warming. Modern civilization...that is another issue. -
Phila at 06:38 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
#48 Mike "It is not the number of reports that matter, it is the quality and impartiality of those reports and so long as we continue to read reports that are clearly biased in that they fail to acknowledge simple things like urban heating, the poor siting of sensors or simple statistical facts like the cooling this century or that if there were warming it would have considerable benefits by reducing the number of cold related deaths in Norther latitudes." Each of these points has not only been "acknowledged," but addressed. Repeatedly. On urban heating, see Are surface records reliable?. On the cooling this century, see Is global warming still happening?. On cold-related deaths, see here. -
Common graphical tricks and the Medieval Warm Period
Mike, > may I ask you how many times a politician has to tell you they saved the planet from global economic collapse for you to believe them? If they have hundreds of rigorous scientific studies and empirical data to back their claim, then once will suffice. > Repetition of the same assertions which are not believed do not and should not increase belief in those assertions. Scientific studies are not assertions, they are examinations of empirical reality using the most objective and effective technique available to humanity: the scientific method. Ironically, a lot of "skeptic" arguments are nothing more than a repetition of assertions, your post being a great example. If you have some specific complaints or questions about the science, please review the list of skeptic arguments on this site, and place your comments under the appropriate post (if you are truly interested in the answers, you should probably read the post as well). > science is inherently sceptical and requires those making assertions to prove what the say; it does not require the sceptic to disprove it! Hence the multitude scientific studies that overwhelmingly support AGW. -
Phila at 06:24 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
#45 Jeff Freymueller "I'm not saying that there isn't or can't be legitimate criticism as well, but my assessment is that most of the "skeptic" criticisms of Mann are based on nonsense (or character assassination)" Well said. Focusing on Mann's reaction to criticism, as some skeptics are wont to do, amounts to little more than ad hominem. How he responds to attacks on his work really has no bearing on the quality or reproducibility of that work. -
Berényi Péter at 06:23 AM on 1 May 2010Why are there fewer weather stations and what's the effect?
Posted by John Cook at 15:28 PM the dropped weather stations actually show a greater warming trend than the kept weather stations Interesting. However, it deserves some checking, doesn't it? So I have fetched current GHCN data form the GISS Temperature site. Raw data are in v2.mean.Z. The readme file is also handy. I have lumped together data according to WMO station number and selected 610 stations that have reasonable coverage for the last forty years (from April 1970 to March 2010). Then I have calculated average temperature trend on this set for each station and for the entire set on the first and second twenty year periods (April 1970 - March 1990 & April 1990 - March 2010 respectively). The warming found is huge and accelerating. It is 0.0239 °C/year for the first two decades and 0.0297 °C/year for the rest on this particular set. Then I have divided the set of stations into two equal subsets. Subset A contains those stations that have the least trend during the first two decades, subset B the rest. Average warming for A in this period is 0.0018 °C/year while it is 0.0461 °C/year for B in this period. And here comes the surprise. For the last two decades the trend for A is 0.0359 °C/year while for B it is 0.0235 °C/year. It is really odd. Let me rephrase it. If stations with the largest warming trend at the beginning were dropped, the rest would show more warming on average, not less. Therefore what Tamino did, is meaningless and you also have to reconsider your points. The vague description of procedure followed is intentional. I would like others to repeat it, with slightly different assumptions, just to see how robust it is. Neither have I applied any adjustments, although it would be easy to repeat it with v2.mean_adj. The result begs for an explanation. My bet would be it is UHI. The local warming influence of human presence is roughly proportional to the logarithm of population density. If population growth is slower than exponential, the UHI effect increases in a sub-linear fashion. If we keep throwing out stations with large warming, the rest is getting more rural with larger warming potential. Indeed, in set B there are considerably more stations flagged rural than in set A. the reason for the "dropped" weather stations is merely the result of stations no longer actively recording temperature data John, this statement is not an adequate description of reality. Find another explanation, please. Weather Underground manages somehow to collect several reports per day for the overwhelming majority of stations dropped from GHCN in 1990 and also for those USHCN stations dropped in 2005. I have started a script that pulls down the daily data from that site. Unfortunately it takes time, for the site is protected against DoS attacks, therefore large pauses are needed between accesses (otherwise access is rejected). They have station histories going back to decades, in some cases as far back as the fifties. With these the hypothesis above can be tested. As soon as I'll have enough data, I will report back. -
Doug Bostrom at 05:50 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
Mike, that was 6 paragraphs and 470 words without a single specific complaint about science or for that matter data visualizations. Not that anybody's counting, but you may have set a record... ;-) -
Doug Bostrom at 05:44 AM on 1 May 2010Where is global warming going?
Suibhne, perhaps I should ask the question a different way. Does energy leave planet Earth? If so, how? -
Mike Haseler at 05:03 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
JMurphy "Just how many studies would be enough to satisfy the so-called skeptics ?" JMurphy, you seem to fundamentally misunderstand the sceptical position. To answer your point, may I ask you how many times a politician has to tell you they saved the planet from global economic collapse for you to believe them? Repetition of the same assertions which are not believed do not and should not increase belief in those assertions. Moreover, science is on the side of the sceptic, because science is inherently sceptical and requires those making assertions to prove what the say; it does not require the sceptic to disprove it! But at a more systemic level, the climate community have systematically failed to address many of the concerns raised by the scientifically sceptical. Rather than accepting reasonable criticisms of the problems of the modelling, "unknown unknowns" and most importantly the abysmal temperature record (my speciality) there has instead been a nasty smear campaign against anyone who dared to be scientifically sceptical. Far from making us believe you are “scientists” this smear campaign smacks of blatant political propaganda and unfortunately anyone no matter how political they are in the subject, is tarred with the same brush. Moreover, the climate community have hardly done themselves any favours by their response to the behaviour revealed in the climategate emails. As some have said such things can go on in any academic field, but whilst a firm rebuke from the discipline would have given us some confidence that the behaviour in the emails was not deemed acceptable, the silence and (from our view) a whitewash of inquiries has shown to the sceptics what we now see as a community of academics with absolutely no willingness to bring the standards of their discipline up to the standards the sceptics believe is appropriate for such a high profile world-wide important and hugely costly area of research. So, much of the sceptical response to the climate community is self inflicted by that community. Most sceptics are not heartless animals. We are mostly people with real life experience or real life situations, where we have seen how people can be misled by statistics and a "bee in their bonnet" to come to the wrong conclusion. It is not the number of reports that matter, it is the quality and impartiality of those reports and so long as we continue to read reports that are clearly biased in that they fail to acknowledge simple things like urban heating, the poor siting of sensors or simple statistical facts like the cooling this century or that if there were warming it would have considerable benefits by reducing the number of cold related deaths in Norther latitudes.... basically so long as we can see the reports are obviously biased, it won't matter how many are produced because our training tells us that it is not scientifically appropriate to “believe” them. -
suibhne at 04:52 AM on 1 May 2010Where is global warming going?
doug_bostrom The planet can heat up and cool down over geological periods. Heating up means gaining internal energy. Cooling down means losing internal energy. -
Jacob Bock Axelsen at 03:53 AM on 1 May 2010Are we too stupid?
embb I forgot to mention. I am contractually obliged to divulge science to the public. How do you imagine tit-for-tat working among states? You defect to fulfill your emission goals, we punish through trade restrictions, UN resolutions, treaties that disfavor your interests, making the IMF put conditions to loans during economic downturns etc. Reciprocity. It gets better. Axelrod points out that a small cluster of players using tit-for-tat may completely eliminate all the defectors (and keep them from reemerging). Quite interesting. Lots of recent research points in that direction incl. the references in my post. Have you read any of them? I can provide a lot more. In terms of environment, no gain at all. There is no environmental gain from preventing climate change? Energy security could be a gain but it is almost accidental - there are cheaper and more efficient ways to achieve energy security. What are those ways? And compared to what, exactly? Do the cheaper ways destroy the planet? I meant security in terms of not being dependent on imported oil, what do you mean by 'energy security'? There is a state above the Californian companies. So your example does not answer my question. The fig tree/fig wasp symbiosis shows that tit-for-tat works without executive power. Isn't it amazing how nature always beats humans in ingenuity? I did not see any acceptable solution Let me reiterate: should anything be done to prevent climate change? -
chris at 03:39 AM on 1 May 2010Skeptical Science talk at University of Qld on May 7
"Qld"? Surely "Qnsld"... -
Marcel Bökstedt at 03:20 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
HumanityRules> New data on the middle age climate arrive all the time, and I don't think that this case is closed yet. But the paper by Mann etc. seems to be a strong paper, even if it does not seem to take all available published proxies into account. I can't see that the paper about South America by Neukom et al. that you linked to contradicts the Mann paper, they claim that the summers in SA were "mostly above the 1901–1995 climatology". They do not claim that they were as warm as now. The paper by Oppo et al. is about the tropical waters around Indonesia, so it's not really southern hemisphere. It also has temperatures around 1200 well below present temperatures, and also estimated temperatures below the estimated North Hemisphere average (figure 3). So I can't see that paper as contradicting Mann's paper either. I'm sure you have read those two papers closer than I have. If I'm missing something, please explain. -
ktam at 03:19 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
I have also recently blogged on why i think the Hockey Stick isn't broken: The Hockey Stick is Accurate -
Jeff Freymueller at 02:23 AM on 1 May 2010Common graphical tricks and the Medieval Warm Period
#35 Humanity Rules, I think it would be a surprise if Mann was NOT defensive, given the politically motivated assault that has been made on him personally and on his work. I think nautilus_mr has it right in #36 about the intuitive power of the hockey stick graph, which is why so much is made in many skeptical camps about that one result. Hint: he's not being attacked because he reacts defensively, but because some don't like the conclusions of his work. Whether ego or other personality factors contribute to his reaction to criticism, I really don't know because I've never met him and only had one second-hand interaction with him. I have my own guesses but it's just speculation. I haven't read all of the relevant papers on the paleoreconstruction topic, but the papers I have read demonstrate exactly what you call for: a drive to improve the science. Criticisms are made and countered in the literature, on this topic as well as many others. What is different on this topic is that there is a firestorm of criticism (and noise and distortion) outside of science because of the political implications of the results. I'm not saying that there isn't or can't be legitimate criticism as well, but my assessment is that most of the "skeptic" criticisms of Mann are based on nonsense (or character assassination) or on nitpicking that has had little impact on any conclusion (the decade claim I mentioned before being the one conclusion that didn't hold up). Otherwise, more than a decade of subsequent work and a lot more data has not altered the fundamental conclusions. The last paragraph of #36 is also on the money as far using science to address issues that are also politically important. On issues of political importance, we know and expect that people with financial interests will hire lobbyists and mouthpieces whose job is to say anything, regardless of facts, to advance the interests of their clients. Scientists have to be careful to stick to presenting the results and implications of their scientific work, but if we don't say what our results are and what our science tells us about potential options and consequences, then I think we would be doing a disservice to the people who ultimately pay the bills for research. -
Doug Bostrom at 02:18 AM on 1 May 2010Where is global warming going?
Suibhne, you don't believe in radiative equilibrium? Can you describe how the planet sheds energy, or is it being stored somewhere inside the globe? -
Bob Lacatena at 02:08 AM on 1 May 2010Tracking the energy from global warming
Just a thought... there is another possibility for where some of the heat could be hiding. Greenland and Antarctic ice melt is, I assume, estimated through the gravity measurements of the GRACE satellite, but that only measures mass change, i.e. ice that melts and then runs off into the ocean (I presume). Suppose the degree of ice melt is much greater than currently assumed, but large amounts of the melt sink into crevasses or seep down in other ways without an opportunity to escape? This is particularly likely in Greenland, where I believe there is a large basin below sea level that would ultimately trap melt water. Based on watching snow melt in my yard (probably not a good model for places like Greenland and Antarctica, where it is densely packed ice instead of loosely packed snow, but...) a lot of the melt water spreads through the depth of the snow and eventually seeps into the ground or runs off from underneath, where it can find an outlet like the edge of the plowed street. This also seems to melt a lot of snow "from the inside" away from the sun by transporting the heat downward in a form of convection. What might happen in Greenland or Antarctica, with kilometers of depth to penetrate before some of the water is redirected outward "toward the street"? Could large crevasses/channels/tunnels be accumulating the water, and melting and growing from the inside from the heat and pressure? I don't know the numbers, so I don't know how much melt would account for what percentage of the missing heat, but it's a scary idea, both in the thought that ice could be melting faster than we think, and that there could be sudden sea level rise events unleashed if some of that reservoir of trapped melt water is unexpectedly released.
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