Recent Comments

Prev  2496  2497  2498  2499  2500  2501  2502  2503  2504  2505  2506  2507  2508  2509  2510  2511  Next

Comments 125151 to 125200:

125151. Berényi Péter at 00:43 AM on 22 January 2010
        Skeptical Science now an iPhone app
        Riccardo, working on a problem for decades is not the same as getting the easy (and most important) part of the job done ASAP. I am not even talking about a full scale reanalysis as it is undersood in "climate science" circles (the one involving extensive statistical data kneading), but straightforward correction for known and deterministic instrumental biases. I am not implying it would be a low budget operation. But it is easy indeed as a scientific endeavor. One does not have to bother with hypothetic climate/atmospheric models and the like, just simple instruments and raw data. Proper collection of metadata, reconstruction of devices and testing their response to varying pressure, temperature, moisture and radiation histories costs money, but does not require much ingenuity. Just plain old honest work. I am surprised beyond imagination that this issue is not pushed much more forcefully. In fact it seems no one has got grant money to do it. Of course there is a danger the results could turn out "supporting lower climate sensitivity than the standard IPCC range". Come to think of it, could be rather difficult to get a grant for this purpose with opinionated referees around. Considering it is THE experimentum crucis for the present climate modelling paradigm, everyone involved should welcome such an opportunity, not suppress it. Just imagine Albert Einstein trying to prevent Sir Arthur Stanley Eddington to get to Príncipe in time to capture full eclipse by "saying people are working on eclipses for millenia, so why the rush". No one doubts the lower troposphere is getting wetter nor older instruments tending to have a longer relaxation time at low temperatures. But I would not bet on correcting for relaxation time bias could charm away the decreasing specific humidity trend measured by radiosondes up there, for this trend is also observable at the 700 hPa level, where all instruments behave reasonably well, even the ancient ones. Also, the ongoing loss of high altitude glacier mass is more consistent with decreasing relative humidity at that level than with a constant one.
125152. HumanityRules at 00:26 AM on 22 January 2010
        Skeptical Science now an iPhone app
        Yet the radiative forcing graph in your response to post #8 would suggest that GISS think solar has remained almost unchanged in it effect for the whole of the century. All the quote from the paapers you mention, including Lassen 1999, suggest solar can only be ruled out for the most recent warming period.
125153. Alexandre at 00:15 AM on 22 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Thanks for the great post, John. The paragraph with the moral of this story summarizes well my own view, too. I'd like to place a suggestion. It's off-topic, but I don't know where else I should send it. I know a few good websites (like this one) dedicated to debunk "skeptical" claims. I've been questioning this approach, though. I think it is much more compelling and instructive to explain the existing science behind AGW then to respond to denialist (mostly) nonsense. People can learn, then, how robust the mainstream consensus is and THEN compare it with the feeble contrarian reasoning. I find it much more constructive. Would it be feasible/interesting to add a section like this here? Could anyone point me a website with this approach?
125154. HumanityRules at 00:15 AM on 22 January 2010
        Skeptical Science now an iPhone app
        Given the good correlation upto 1975 do we conclude that solar was the dominant factor controlling change in global temp for the first 3/4 of the century?
125155. chris at 00:09 AM on 22 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        re #7 sweart, I think you're being unfair on Barnett et al. (2005). If you read their section on Himalaya-Hindu-Kush, which they address as a whole region, they makesome rather uncontroversial statements that are referenced by 5 citations, one of which is the report of the China Glacier Inventory. They state:

        There is little doubt that the glaciers of the HKH region are melting and that the melting is accompanied by a long-term increase of near-surface air temperature (ref. 44 and Figs 2.9 and 2.10 in ref. 1), the same level of warming we saw impacting the western USA. After 25 years of study, the China Glacier Inventory was recently released45. It showed substantial melting of virtually all glaciers, with one of the most marked retreats in the last 13 years (750 m) of the glacier that acts as one of the major sources of the Yangtze River, the largest river in China. In total, it is estimated that the entire HKH ice mass has decreased in the last two decades. Furthermore, the rate of melting seems to be accelerating46. The few analytical studies that exist for the region suggest both a regression of the maximum spring stream-flow period in the annual cycle by about 30 days (ref. 47) and an increase in glacier melt runoff by 33–38% (ref. 48). These numbers seem consistent with what is being observed and bear striking similarities to the stream-flow results from the western USA. The huge inconsistency, however, occurs in the impacts on local water supplies. In the western USA, model-predicted impacts are already being seen in the hydrological cycle. The models suggest that the impacts will appear as a long-term trend in snow amount and runoff. But in the HKH region, there may (for the next several decades) appear to be normal, even increased, amounts of available melt water to satisfy dry season needs. The shortage, when it comes, will likely arrive much more abruptly in time; with water systems going from plenty to want in perhaps a few decades or less.

        So the Chinese studies certainly don't address "one ice mass"...moreover the authors are quite clear that the IPCC citation refers specifically to air temerature (see reproduced text above). Barnett et al (2005) also cite studies for this region that address the strength of glacier-fed stream flow and glacier melt run-off. Reading this section, and in the context of the whole article, doesn't suggest that there's anything wrong with the article, certainly not to the extent that one would question the peer-review process. Total Himalayan glacier mass balance is negative[*], and that's what Barnett et al (2005) state, and discuss implications thereof. [*] http://web.hwr.arizona.edu/~gleonard/2009Dec-FallAGU-Soot-PressConference-Backgrounder-Kargel.pdf
125156. decliner at 00:03 AM on 22 January 2010
        There is no consensus
        Tom, I dismiss all skeptic work, as does anyone who understands how science works. What an irony that you are worried about people being sceptic but in the same time defend someone whose ideas neglect the validity of science in general.
125157. Berényi Péter at 22:48 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        The Himalayan glacier issue is a complex one. MoEF Discussion Paper Himalayan Glaciers A State-of-Art Review of Glacial Studies, Glacial Retreat and Climate Change - V.K.Raina, Ex. Deputy Director General, Geological Survey of India http://gbpihed.gov.in/MoEF%20Dissussion%20Paper%20on%20Himalayan%20Glaciers.pdf Also, the constant mid & upper tropospheric relative humidity hypotheses is not supported by (sub)tropical glacier shrinkage. Especially during the sixties and seventies, when temperature decreased, but glacier mass loss only slowed down, not reversed. On the other hand, if air above 1500-2000 m is getting ever drier as CO2 goes up, glaciers should shrink. It is even more pronounced on Kilimanjaro, Africa, where sublimation is the dominant ice loss process.
125158. Spencer Weart at 22:36 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Supporters of the IPCC should be first to note that a similar error is found elsewhere in the Working Group 2 report, in chapter 3. In section 3.4.3 we read that “the entire Hindu Kush-Himalaya ice mass has decreased in the last two decades.” The citation is to Barnett et al. (2005), a Nature paper that does indeed say the Himalaya-Hindu Kush area was losing ice. So far so good. But the refereeing there failed, for Barnett et al. cite only two sources for their confident statement: a Chinese paper that, judging from the title (I haven’t tried to find the whole text), actually studied only one ice mass... and figures in the IPCC 2001 report, which turn out to show only temperature rise over the Himalayas, not actual glacier retreat. In short, the scientific communities involved had really poor quality-control in this case, not just at the IPCC level but in the Nature article refereeing. Oh well, historians of science know that it is a rare scientific paper that does NOT contain an error; that's the inevitable result of working at the frontier of knowledge. Himalayan glaciers depend crucially on the notoriously fickle monsoon, and glaciers in general depend as much on precipitation as temperature (like many tree rings!). The Physical Sciences panel was rightly concerned above all with ice mass, a lot of which is in ice caps rather than glaciers. The crucial data for the Panel I report are to be found at http://instaar.colorado.edu/other/download/OP58_dyurgerov_meier.pdf with a broader overview at http://www.hydro.washington.edu/.../kaser_et_al_grl_2006.pdf (I guess published too late to be included in the IPCC reference list, but they do show the figures.)
125159. Marcus at 21:28 PM on 21 January 2010
        Two attempts to blame global warming on volcanoes
        From Peru. Just a possibility, but could this maybe be the result of a lack of data from the USSR during at least some of this period? I'm not saying this is the case, merely hypothesizing.
125160. David Horton at 20:50 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        #3 Chriscanaris - "I have come across reports that some glaciers may be growing ... If so, what's the overall significance?" John has answered this in terms of proportions. Something worth adding is that because glacier size is determined (simplistically) by the balance between snow arriving at the top end, and ice melting at the bottom end, they will react to global warming in ways depending on their geographic situation. In most cases (over 90%) the equation is simply that global warming brings more melting and less snow. In a small minority of cases, especially those in coastal regions, although the bottom is melting faster, the warmer sea also results in more snowfall at the top. If the latter factor outweighs the former, the glacier can actually grow. It is not clear to me whether this is a temporary effect, and that temps continuing to rise will shrink these glaciers too, or whether snowfall can continue to increase proportionately. My gut feeling is that the increase in snow is likely to be a short term phenomenon, which seems to be suggested by the falling proportion of glaciers that are growing.
125161. Jesús Rosino at 20:27 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        The link to the Kotlyakov report is now broken, you can find it here (p. 66).
125162. Jesús Rosino at 19:53 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Thanks for the summary, John. I really like that you cover the current affairs. Although the reference was the WWF 2005 report, it seems that the IPCC text was more likely paraphrased from an article published in the India Environement Portal in 1999:

        "Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 is very high," says the International Commission for Snow and Ice (ICSI) in its recent study on Asian glaciers. "But if the Earth keeps getting warmer at the current rate, it might happen much sooner," says Syed Iqbal Hasnain of the School of Environmental Sciences, Jawaharlal Nehru University, New Delhi. Hasnain is also the chairperson of the Working Group on Himalayan Glaciology (WGHG), constituted in 1995 by the ICSI. "The glacier will be decaying at rapid, catastrophic rates. Its total area will shrink from the present 500,000 to 100,000 square km by the year 2035," says former ICSI president V M Kotlyakov in the report "Variations of snow and ice in the past and present on a global and regional scale".

        As Deltoid mentions, John Nielsen-Gammon has a grood article on the original sources, including the Kotlyakov report, where the year 2035 may come from as a misreading of 2350 (here and here) As for the real consensus on the Hymalayan glaciers, the link provided by RealClimate to Karger et al at the AGU press conference last December is very good (see slides 13 and 40-41).
125163. Riccardo at 19:47 PM on 21 January 2010
        Skeptical Science now an iPhone app
        Berényi Péter, the intercomparison between the various reanalisys in Trenberth et al. shows which is more reliable; Paltridge et al. failed to notice it. But the point is not even this. It is that due the unreliability of radiosonde data no strong conclusions can be draw, as you (not Paltridge) are trying to do. You surely read what Paltridge wrote on Climate Audit; there was no political bias to force him to state that radiosonde data are not reliable, but he confirmed. This leaves no room to your (arbitrary) hypothesis that he was forced to write so to pass a biased peer review. Your idea on how reanalysis work is really trivial. You are assuming that we now know for all the stations, all the flights, all the instruments and all the sensors the influences of an uncontrolled ambient on the measurements, which is clearly not true. It should not be so hard to see given that we have several different and contrasting reanalysis and people working on it for decades. Were it so simple as you say anyone could have done it.
125164. Riccardo at 19:30 PM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        Humanity Rules, yes, we are looking a temperature and ENSO do have an effect. But given that no energy is produced it can just cause fluctuations, not trends. I already explained why i took just part of the time range available. From around the '70s the contribution of GHG to warming has been strong enough to be clearly identified and the sun forcing has been roughly constant. If you want to reproduce the whole instrumental record from 1880, you need to put together all the contributions to forcing.
125165. chris1204 at 18:38 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        I have come across reports that some glaciers may be growing (alas I do not have sources to hand). If so, what's the overall significance?
        Response: Some glaciers are growing. In fact, the IPCC mentions them in their section on glaciers - including a Himalayan glacier in the Karakoram mountains. However, these are isolated cases - the vast majority of glaciers are shrinking and the shrinking trend is increasing. According to the World Glacier Monitoring Service, 77% of monitored glaciers were retreating in 2002. This was followed by 94% of monitored glaciers retreating in 2003. The global trend is accelerating shrinkage:
        
        
        Cumulative mass balance curves for the mean of all glaciers and 30 'reference' glaciers (WGMS 2008).
        
125166. David Horton at 15:35 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Yes, this has all been as much, if not more, of a beat up than the "hide the decline" nonsense. But the two together clearly signal a new determination by the denier, and those behind them, to stop at nothing in order that the world will stop at nothing. I saw one comment to the effect that if the glaciers were going to melt in 25 years that would be a cause for concern but 340 years, who cares. The idea that glaciers are already retreating, all over the world, and that they are acting as one of the canaries in the coalmine escapes these people (and the mass media, including people like the Guardian, and the ABC, who should know better). Similarly the idea that whether it is 35 or 350, the processes are now in place for yet another unthinkable thing to happen, inevitably, has also escaped the deniers. And the obvious point that since the glaciers are already in retreat, the effects of this are already underway. I think there is plenty of room for debate on all kinds of timing issues (sea level rise and acidification, desertification, increasing storm frequency, ice free Arctic, loss of Greenland ice cap and so on). They are of some practical import, but really the exact speed is a matter of mainly academic interest. If you are stalled on a level crossing, the approaching train could be coming at any speed really. but getting off is the important thing. In fact an emphasis on the speed at which things are happening lets politicians off the hook - plenty of time to deal (or have someone else deal) with that, they think. The important message though, is that these effects are now built into the atmosphere, and it is going to take a long time to turn them around.
125167. From Peru at 14:56 PM on 21 January 2010
        Two attempts to blame global warming on volcanoes
        It is an interesting possibility, but this graph: http://data.giss.nasa.gov/gistemp/graphs/Fig.A4.lrg.gif Shows that the discrepancy is GREATER IN LAND than in the Global Oceans. Whatever the cause is, this strange behaviour ONLY occurs in NORTHEN LATITUDES(23,6ºN-90ºN): http://data.giss.nasa.gov/gistemp/graphs/Fig.A3.lrg.gif http://data.giss.nasa.gov/gistemp/graphs/Fig.B.lrg.gif
125168. Tony O at 13:13 PM on 21 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        The glaciers are retreating and there will be significant consequences long before they are all gone. Deltoid has an interesting study on how the error occurred. The trouble with peer reviewed is that it is usually behind a pay-wall and I am not paying to read an article that I probably will not understand. I am also learning there is peer review and then peer review, some peer reviewed journals have a much higher standing than others. What I have learned from the peer reviewed articles is that there is still a high degree of uncertainty on how glaciers will react. Melt they will but how fast and what mechanisms will come into play.
        Response: The Deltoid article is A beat up of Himalayan proportions.
125169. chris at 11:06 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        Well yes HumanityRules, by why pretend that one should fit the earth's temperature evolution to a single contribution (whether ENSO or solar or CO2)? Why would we throw out everything that we know in pursuit of a spurious "argument" that we know is wrong? Obviously to reproduce the 20th century temperature we should include all of the contributions and their amplitudes and temporal variation. Anthropogenic greenhouse forcing predominates, but anthropogenic aerosols, black carbon, volcanoes, solar etc. all contribute to the temporal variation in surface temperature. See for example Figure 1 here: http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf In relation to your post #38, to point out that solar irradiance change has made no significant contribution to warming since the 1950's, and likely a small cooling contribution since the mid 1980's, is not to dismiss solar irradiance changes as a contribution to surface temperature change - it just hasn't made a contribution since the 1950's. That's all very straightfoward isn't it? To address attribution to surface temperature variation we address all of the contributions according to their individual effects during the period of interest...
125170. Berényi Péter at 10:50 AM on 21 January 2010
        Skeptical Science now an iPhone app
        chris, the McCarthy at al. paper is outrageous. One simply does not use such a convoluted series of ad hoc data "enhancement" techniques. Never. It is horrible, worse than guesswork. http://findarticles.com/p/articles/mi_7598/is_20091115/ai_n42654412/?tag=content;col1 The first thing to do, as I have already mentioned, is to identify the instrument type used for each measurement, then correct for deterministic errors using experimentally established instrument profiles. It is a plain engineering job, it has nothing to do with climate science. All else comes later. However, McCarthy et al. are trying to do it the other way around. With a flawed method like this one cannot even reject the underlying null hypothesis that planetary constellations determine human fate. "(v) In the meantime the requirement for detailed analysis of the upper tropsophere is being met through the use of satellites carrying instrumentation designed for determining (amongst other things) upper tropospheric humidity and temperature." No, they were not designed to do that. Satellites detect IR radiation in certain narrow frequency bands. One can apply an inverse transformation to get upper troposphere RH and temperature values from these measurements, but only relative to a fairly detailed atmospheric model. The values themselves depend both on model and the radiation measured. The particular radiation transfer model used is also crucial. Even with these caveats the vertical resolution is rather poor and error bars are huge due to the much larger lower troposphere specific humidity background. It fails completely if clouds are present. Riccardo, Trenberth at. al 2005 consider the total integrated water vapor column indeed, which has no relation to the radiation balance at TOA. It is upper troposphere moisture we are talking about, a tiny portion of total integrated water vapor column, but this is the level where thermal radiation emitted by vapor has a chance to escape to space. Of course they discuss radiosonde relative humidity measurement problems, but only vaguely. They refer to problems with satellites as well. I would also rather leave political comments out and concentrate on the scientific contents if it were possible. It is not. An anonymous referee of the Journal of Climate on the Paltridge paper: "the only object I can see for this paper is for the authors to get something in the peer-reviewed literature which the ignorant can cite as supporting lower climate sensitivity than the standard IPCC range". It is unbelievable. I know of no other branch of science where peer review is allowed to venture this far. Alas, this particular guy was not disqualified by the editor.
125171. HumanityRules at 10:41 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        Riccardo, I get that ENSO doesn't produce energy only redistributes it but this manifests itself as an increase in global temp which is the measurement we are comparing these things to. Although the potential to alter water vapour in the atmosphere would You're also asking me to fit ENSO to temp increase, something I agree you can't do well but then as I keep saying the graph of CO2 increase doesn't fit well to temp either. Why would you start the analysis at 1970 when you have data back to 1950?
125172. Tom Dayton at 10:25 AM on 21 January 2010
        There is no consensus
        decliner, your complete dismissal of Kuhn's knowledge of philosophy of science belies your claim that you know philosophy of science "rather good" [sic].
125173. decliner at 05:57 AM on 21 January 2010
        There is no consensus
        "one of the earliest people who did the most to get widespread recognition of that fact." I know, I just think it's obvious that Kuhn got it wrong. You're absolutely right, I'm not a scientist, but I know philosophy of science rather good. To say Kuhn is an expert in that field would be like saying Justin Timberlake is one of the great modern Artists. Happily the ubiquitous misunderstanding of philosophy of science by some scientists doesn't harm the quality of their work. I basically agree about consensus being important. But still, consensus isn't the reason why science tells me there is AGW, it's the other way round, there is consensus because of the scientists understanding of the facts. "It certainly is fair!" Oh, yes, it is. My bad. Still the foia-emails show the peer-system somewhat being corrupted. "require human judgment" Yes, but that human judgement is not achieved by consensus. consensus is achieved by human judgement. human judgement being a diffuse term for the application of rational reasoning leading to prove. "the best way to find out is to have a motley gang of experts try their damnedest with motley approaches to show it is wrong." While this is true, I don't think this was at every time the attitude of leading climate scientiest. One doesn't need to be a sceptic to be concerned about how Mann and others reacted to criticism, wouldn't you agree? "That is off-topic for this thread" Every single sentence i wrote on this thread could be labeled off-topic. :) But thank you. I will post there.
125174. chris at 05:22 AM on 21 January 2010
        Skeptical Science now an iPhone app
        re #70/71; Peter your arguments are not very pertinent to the matter at hand. There are a couple of "bottom line" conclusions that we can make. (i) There's no question that it is accepted that radiosonde data on high altitude temperature and humidity are not sufficiently accurate as they stand to make strong conclusions about the validity of expected/simulated parameters in the upper troposphere. (ii) That's simply a fact of life. The radiosondes were not designed for high precision measurements of the sort that are required to address long term trends in upper tropospheric parameters; they were designed to supply networks for numerical prediction of weather. (iii) The very paper that you've brought to our attention here incorporates this essential proviso that the data may well be a result of "problems with the instrumentation and operation of the global radiosonde network". It's not obvious why you choose to pretend that this proviso is not an important part of Paltridge's paper. (iv) None of this is a reflection on the excellent work that those involved in the radiosonde network for atmospheric analysis and weather prediction have put in over the years. Unfortunately, the requirement for rather more detailed analysis of upper tropospheric parameters is not met by the radiosonde network, particularly as it existed in the earlier decades required for establishing longer term trends. (v) In the meantime the requirement for detailed analysis of the upper tropsophere is being met through the use of satellites carrying instrumentation designed for determining (amongst other things) upper tropospheric humidity and temperature. In general these data are rather consistent with expectations from enhanced greenhouse warming in terms of upper tropospheric temperatures and humidty. (vi) We certainly don't know the whole story yet. However it would be foolish to attempt to reconcile expectations/predictions from theoretical understanding/simulations with radiosonde data on upper tropospheric humidity, when there is a significant question about the accuracy of the radiosonde measurements. (vii) In the meantime a recent very detailed analysis of radiosonde data indicates that tropospheric humidity has increased much as expected from models [*]. That’s not the whole story either. However I’m inclined to consider the large number of studies on tropospheric water vapour trends from radiosonde reanalysis and satellite measures that show tropospheric water vapour increasing much as expected from theoretical understanding of the response to atmospheric warming, over a single weak paper which restates what everyone already knows, and that carries the repeated proviso that the results presented may be a result of "problems with the instrumentation and operation of the global radiosonde network". At the very least the null hypothesis that tropospheric water vapour concentrations are increasing as expected from our understanding of the response to tropospheric warming, isn’t disproven by the single weak analysis you brought to our attention. [*] M. P. McCarthy et al. (2009) An Analysis of Tropospheric Humidity Trends from Radiosondes Journal of Climate 22, 5820-5838 http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2009JCLI2879.1
125175. Tom Dayton at 04:50 AM on 21 January 2010
        There is no consensus
        decliner wrote "did you realize that Naomi Oreske used an image taken from climate audit? Climate audit states that this graph was made by data which was lost, so its validity can't be controlled. Isn't it strange that someone would take this into a pdf as a prove?" That is off-topic for this thread, but if you can find the place where ClimateAudit makes that claim (I couldn't find it in the mere 10 seconds I looked), you might post a question about it in the SkepticalScience post Can you make a hockey stick without tree rings? if the purportedly lost data are temperature data, or in There’s no correlation between CO2 and temperature if the purportedly lost data are CO2 data.
125176. Tom Dayton at 04:35 AM on 21 January 2010
        There is no consensus
        decliner, Sometimes you'll see someone respond to deniers' claim that science requires proof rather than consensus, with the response "Proof is used in math, not in science." But even that response is not correct, because mathematicians also rely heavily on consensus. They, too, rely on peer review, because they, too, require human judgment of whether a purported proof is correct.
125177. chris at 04:32 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        To extend Riccardo's answer: You really need to understand what the ENSO Index is, HumanityRules, before attempting to use it to assess its contribution/response to surface temperatures under the influence of external forcing. There are two main problems with your analysis: (i) Yes, linear regression of the MEI Index gives a slope of 0.0136 yr-1. However the Index is just an Index. If one wants to consider its contribution (if any) to the surface temperature trend, one would (at least) have to normalize the index with respect to temperature. One way one to do this might be to observe that the very strong El Nino of 1997/1998 lifted the 1998 surface temperature around 0.2 oC above the long term temperature trend. Thus we could scale the Index (crudely) by estimating that an Index value of 1.5 is equivalent to 0.2 oC of surface temperature. This would give a very crudely "temperature-normalized" trend of 0.018 oC per decade (compared with a surface temperature trend 0.11 oC). (ii) However that analysis still overestimates the contribution of ENSO to any trend since one of the parameters of the multivariate analysis that yields MEI is sea surface temperature. This is increasing in a warming world as a result of enhanced radiative forcing. In fact it is considered that as the earth warms we will expect to shift ENSO towards more frequent El Nino states, tending perhaps to permanent El Nino states. Since the MEI Index has a sea surface temperature componewnt, the ENSO Index must rise in time unless there are compensating components of the Index that decrease in a warming world. So it is the latter effect that is likely the cause of any apparent trend in ENSO as determined by linear regression of the MEI Index. As Riccardo says, ENSO can't generate heat, it largely redistributes this within the ocean. (iii) Obviously the best means of attributing contributions to surface temperature is to assess the individual contributions and combine these to reconstruct the record of temporal temperature variation in response to internal/external forcings and any oscillatory contributions, rather as is done here (see Figure in post #8): http://www.skepticalscience.com/What-does-Solar-Cycle-Length-tell-us-about-the-sun-role-in-global-warming.html One would find that while ENSO makes essentially no contribution to the trends, it accounts for a substantial part of the variability around the trend (as Riccardo also said!).
125178. Tom Dayton at 04:27 AM on 21 January 2010
        There is no consensus
        decliner #194 wrote "Also the argument 'The contrarian claims are the ones that fail peer review' ain't fair." It certainly is fair! Peer review is phase 1 of scientists' "battering" on conclusions, that I mentioned in my previous comment. That's one of the things Gavin was commenting on, in his quote that I included at the end of my previous comment. The issue is not just any given submission's failure to make it into one given journal. In all scientific fields, a fair number of papers that eventually turn out to be correct and highly valuable are rejected by several journals before finally being accepted by one. That is frustrating (to say the least!) for those authors, but we (working scientists) don't consequently dismiss the entire scientific publication system as a consequence, because we very much value the quality filtering that usually works well, and because we know that conclusions that are correct eventually will make it through peer review. What's telling about AGW deniers' "work" is that it fails to pass peer review ever. It consistently fails to pass the very first quality filter.
125179. Tom Dayton at 04:13 AM on 21 January 2010
        There is no consensus
        decliner #194: Naomi Oreske is a "she," not a "he." Oreske was not referencing Kuhn as argument from authority to support her contention that science includes application of community standards. Instead she was: (1) Tipping her hat to him as one of the earliest people who did the most to get widespread recognition of that fact. (2) Shortening her presentation and preventing it from diverging from its overall purpose, by using "Kuhn" and "community" as shorthand for a large body of literature--certainly not all written by Kuhn. (3) Pointing to a path for anyone who wants to learn more or even disagree with that particular point. For example, you can simply search the internet for "science Kuhn community standards" to find a large number of discussions such as, oh, just for instance the second hit from Google: a paper by Duffy Hutcheon. Those three purposes of Oreske's reference to Kuhn are standard in scientific writing. So your blanket dismissal of her reference to Kuhn is inappropriate. But no harm, no foul, since you aren't a working scientist, you wouldn't have known that. You don't need to invoke Kuhn to support the importance of consensus in science. The history of scientific practice shows unequivocally that convincing other scientists is a core part of what working scientists actually do. And "science is what scientists do." (Search the internet for that phrase.) The reason is that science is about making decisions, and human judgment is needed to make those decisions. Most AGW deniers who object to consensus being important, have gotten their idea of science from lower-level classes (even introductory college classes have this problem, it's sad to say) that focus on narrow, purely experimental, methods that are used to address narrow hypotheses, rather than on all the research methods that are used (e.g., quasi-experimentation), and ignoring the theories and theoretical frameworks in the large. Thus the deniers' focus on narrow interpretations of falsification in the context of pure experiments. No matter how foolproof a conclusion seems, it might be wrong, and the best way to find out is to have a motley gang of experts try their damnedest with motley approaches to show it is wrong. The survival of that conclusion despite that battering is good evidence for its soundness. It is an incontrovertible fact that this is how scientists actually work. Go to a conference and see the arguments in the halls (and especially the bars afterward!). Read the articles and notice how common the disagreements are. Look behind the journal editorial curtain to see the drama and contention over article submissions' consideration for publication. Contention is good for science; contention is one of the core aspects of what scientists do, and therefore of science. That's why scientists encourage contention. An example is Gavin Schmidt's remark about the recent Lindzen and Choi paper:

        LC09 was not a nonsense paper -- that is, it didn't have completely obvious flaws that should have been caught by peer review (unlike say, McLean et al, 2009 or Douglass et al, 2008). Even if it now turns out that the analysis was not robust, it was not that the analysis was not worth trying, and the work being done to re-examine these questions is a useful contribution to the literature--even if the conclusion is that this approach to the analysis is flawed. More generally, this episode underlines the danger in reading too much into single papers. For papers that appear to go against the mainstream (in either direction), the likelihood is that the conclusions will not stand up for long, but sometimes it takes a while for this to be clear. Research at the cutting edge -- where you are pushing the limits of the data or theory -- is like that. If the answers were obvious, we wouldn't need to do the research.

125180. Riccardo at 03:37 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        HumanityRules, i forgot to mention one more step you should take even if you do not understand the meaning of the MEI index. Try to fit the temperature trend with the MEI index alone (scaled by some factor) instead of just say they are both increasing. You won't be successful. Try instead a straight line plus the MEI index and you'll account for both the trend and a great part of the short term variability, at least in the period after 1970.
125181. Riccardo at 03:26 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        HumanityRules, ENSO, by definition, cannot create energy, it's just a redistribution of energy through the climate system. If we were able to calculate the energy fluxes they _must_ average to zero unless there's something else providing the energy. The MEI index is more complicated in what it includes other parameters, six overall including surface air temperature. Your comparison is then misleading. The MEI index is useful to account for short term global temperature variability but not for long term trends.
125182. From Peru at 03:23 AM on 21 January 2010
        Two attempts to blame global warming on volcanoes
        John Cook: About early XX century warming (1910s-1940s): Given that: -TSI peaked in the 1960s. -Major volacnic eruptions began in the 1960s with Mount Agung. -NASA GISS estimates that TOTAL FORCING peaked in the 1950s at near 0,5 W/m^2. But temperatures peaked in the 1940s, then slight cooling began until the 1970s (while the forcing continued to grow up until the 1950s-1960s) Any idea why temperatures peaked ONE DECADE BEFORE (the 1940s) the total forcings (according to NASA GISS) peaked in the 1950s?
        Response: Perhaps part of the effect you're looking at is explained by problems with sea surface temperature measurements in the 1940s. When all forcings are considered (the pink bar in the figure below), they show a close match with land temperature. The forcing does seem to reverse slightly after temperature reverses but is within uncertainty bounds. However, in the 1940s, the ocean temperature falls well outside model uncertainty bounds. The paper A large discontinuity in the mid-twentieth century in observed global-mean surface temperature (Thompson 2008) explains that this is due to a change in the method of measuring ocean temperature in the 1940s which caused a spurious warming signal. As far as I know, the global temperature record still hasn't been updated to adjust for this effect.
        
        
        
125183. HumanityRules at 02:07 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        #40 reply So I read " impact of El Nino on long term climate trends here..." and this jumped out at me "The Southern Oscillation Index shows no long term trend (hence the term Oscillation)",. Which seemed to conradict what I said earlier. So i got to thinking if you got an oscillation and you only examine a short section of it then what you've got is a trend (eg the up slope only or the downslope only). So I dug out the ERSL MEI data and the GISS temp anomoly data (thank god for jet lag). http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt http://www.esrl.noaa.gov/psd/people/klaus.wolter/MEI/table.html And I plotted annual average data for 1950-2009 (full extent of MEI data). And I added a linear trend line. Both have a positive trend (MEI slope +0.0136 and temp anomoly +0.0109). Seems Riccardo understands each La Nina and El Nino as an isolated event. Can you not understand this as an on going process with additive effect?
125184. Paz at 00:15 AM on 21 January 2010
        Scientists can't even predict weather
        John Russell: great analogy, thanks a lot!
125185. Riccardo at 00:08 AM on 21 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        HumanityRules, if i want to describe the ascent to Mt. Everest i do not start from the airoport where i live; i will start from the base camp at 5000 m. So, a _general_ description of the climate is one thing, pointing to the effect of CO2 is another. For the latter, i'd start when it is more clearly visible, not when the signal is low and confused by other effects. No one is trying to "take a single effect"; on the contrary, because there are many and i want to describe as clearly as possible just one, i'd just use part of the data. If i want to show the effect of ENSO, i'll use a period around 1998 where the ENSO signal is more evident. Wouldn't you? And as for ENSO, once and again, while it is a good part of climate variability it does nothing to the long term trend. It makes no sense keep saying that it has a huge effect on climate ... You know, in 2008 we had the effect of La Nina and the temperature was relatively low, last year we had El Nino and the temperature increased. Put the numbers, an anomaly (GISS) of 0.43 °C in 2008, 0.57 in 2009; an increase of 0.14 °C. The big one, 1998 was 0.56 °C, 1999 was 0.32, a decrease of 0.23 °C. Can you see what the numbers tell us?
125186. HumanityRules at 23:14 PM on 20 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        Riccardo the fallacy is to take a single effector of climate and plot it against global mean temperature and then say "hey presto" the relationship breaks down here. That seems true whether you're a sceptic or a believer. And to completely contradict my point heres something thats been bugging me a while. Looks at this graph of ENSO index http://oceanworld.tamu.edu/resources/oceanography-book/Images/elninoindex.gif There are many other variations of this on the web if you want to search for them. Look around 1978 there seems to be a general shift. Before mainly blue (negative) after mainly red (positive). This is also the time when the most recent period of temperature increase also kicked in. If El nino and La nina can have dramatic affects on global temperature measurements, and if we see a resumption of increased temperature change around this period, can this not be an explanation of late 20th century temperature increase. John accepts that the radiative forcing of CO2 took a back seat in the mid-century cooling to another factor then why not that it's taking a back seat (along with TSI) to ENSO in heating in late 20th century.
        Response: Let me be clear about the point being made in the comparison between sun and global temperatures. I am not saying the sun doesn't change climate. I'm just making the simple point that during the last few decades of global warming, the sun has been going in the opposite direction. So any contribution the sun has made to global warming is actually a cooling effect.
        
        But like I say all the time, and I think the point you're trying to make - we need to look at the broader picture and take into account all the forcings that drive climate.
        
        BTW, we examine the impact of El Nino on long term climate trends here...
125187. Riccardo at 20:03 PM on 20 January 2010
        Skeptical Science now an iPhone app
        Berényi Péter, i would leave political comments out and think of the scientific weakness of Paltridge paper instead. In 2005, well before Paltridge et al. paper, a much more extensive analysis of water vapour datasets had been published; Trenberth at. al 2005 compared four different reanalisys (two versions of NCEP, NVAP and ERA-40) and SSM/1 satellite data. Although they considered the total integrated water vapour column, the problems with both NCEP and NVAP were clearly noticed. Paltridge et al. didn't even refer to Trenberth et al. work; honestly, i'm not that surprised that it has been rejected on J. Clim. This does not mean that those datasets should be thrown away, but the caution in using them is required, for _scientific_ reasons.
125188. Philippe Chantreau at 19:17 PM on 20 January 2010
        Two attempts to blame global warming on volcanoes
        H.R.there is no lack of consensus among scientist on the climatological effects of volcanic activity.
125189. Riccardo at 18:23 PM on 20 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        HumanityRules, nobody, as well, is suggesting that John is infallable. But, as he himself just explained, there's a logical fallacy in your request; showing what yout asked to show is usually done just to fool people.
125190. Berényi Péter at 18:08 PM on 20 January 2010
        Skeptical Science now an iPhone app
        Riccardo at 06:21 AM on 17 January, 2010: "the authors themselves are much more prudent" The Paltridge paper was submitted to the Journal of Climate in March 2008. Prudent or not, it was rejected on plainly _political_ grounds. It got published almost a year later in February 2009 by Theoretical and Applied Climatology.
125191. decliner at 17:29 PM on 20 January 2010
        There is no consensus
        Tom: Ah, yes, it's adressed in the pdf. "Opposite is true: Science is precisely about consensus, because consensus is the result of the application of community standards." By community standards he seems to refer to Thomas Kuhn, (someone I wouldn't cite if I wanted to be taken seriously). Still the sentence doesn't make much sense to me. the counter-argument would go more like: "the fact that there is consensus is just an answer to those sceptics arguing that there is no consensus. It was the sceptic side that brought up the subject." btw. did you realize that Naomi Oreske used an image taken from climate audit? Climate audit states that this graph was made by data which was lost, so its validity can't be controlled. Isn't it strange that someone would take this into a pdf as a prove? Also the argument "The contrarianclaims are the ones that fail peer review" ain't fair.
125192. From Peru at 16:36 PM on 20 January 2010
        Two attempts to blame global warming on volcanoes
        How can I post IMAGES? I have some beautiful graphs, but when I tried to "cut and paste" (that is, to "paste" the graph in the comment) the graph didn't appeared. What should I do to post graphs or any other image?
        Response: I would suggest uploading them to a free image website (does Flickr let you do that kind of thing) then use the HTML IMG tag <img src=http://www.otherwebsite.com/image.jpg> to display the image in your comment.
125193. decliner at 16:12 PM on 20 January 2010
        There is no consensus
        Tom Dayton: Thank you. Please don't get me wrong - it's not an argument which i endorse (While a consensus doesn't prove something the existence of it doesn't prove its opposite). I just stumbled across it several times reading conservative authors (like the guy who got parodised on southpark recently), so I think it would deserve its own page. :)
125194. decliner at 16:00 PM on 20 January 2010
        It's the sun
        Wow, thanks for the fast reply. It has been a while since I've seen the propagandistic "great global warming swindle" but it look like you're quite right about them hiding the decline. even tough it seems to me they at least didn't substitute it with instrumental data (i guess the red curve is the one for solar activity?) - but it's bad enough anyway. if the factor which is influencing tree ring growth is profoundly understood then it should be possible to correct for that influence, wouldn't it? Will read your page on that subject now.
125195. Tom Dayton at 15:58 PM on 20 January 2010
        There is no consensus
        Decliner, the role of consensus is addressed in Naomi Oreskes's "Consensus in Science: How Do We Know We're Not Wrong?".
125196. HumanityRules at 15:32 PM on 20 January 2010
        Two attempts to blame global warming on volcanoes
        This is similar to the TSI article earlier. We have multiple factors affecting global temperatures. If you try to take one of those factors such as volcanism or CO2 concentration and find a perfect relationship with global temperatures your going to fail. At certain time periods the relationship will breakdown and that can be highlighted to rubbish any connection. Do we believe that volcano activity has an overall affect on global temperature? It must do something (positive, negative or no overall affect). To highlight the lack of consensus on exactly what volcanos do is to just show how we need to improve our knowledge on this subject. Can we be concrete on our understanding of CO2 affect on global temps when we can't control for all the of factors affecting temp.
        Response: I wasn't highlighting the lack of consensus among scientists - I was pointing out the lack of consensus among skeptics. Skeptic arguments may contradict each other but they all have one thing in common - sow doubt so as to delay action on cutting carbon emissions.
        
        We do have a fairly high degree of understanding of how volcanoes affect climate. This was demonstrated when Mount Pinutabo erupted. It gave climate scientists the opportunity to predict how global temperatures would respond to the injection of sulfate aerosols in the atmosphere. Hansen 2007 compares the model predictions to actual observations, shown below. The model results also confirmed the climate's net positive feedback - as temperatures cooled, water vapour in the atmosphere lessened which amplified cooling.
        
        
        
125197. decliner at 15:12 PM on 20 January 2010
        There is no consensus
        While I agree that there is consensus I have another argument (used by several guys) for you to debunk: Science is not about consensus.
125198. decliner at 15:07 PM on 20 January 2010
        It's the sun
        This solar graph has some resemblance to the tree ring proxy graph where mike's nature trick was applied to - to hide the decline. So couldn't you just use the trick as well? Then it would fit the instrumental data better. (This is not meant as a mocking, a serious reply would be appreciated.)
        Response: It's funny you should mention that. I'd not thought of it that way before but "hide the decline" is exactly what the Great Global Warming Swindle did when comparing sun to climate. They deliberately cut off solar levels at 1975. And as if this graphs wasn't misleading enough, they also "hide the incline" of temperature rise in 1980 - global temperatures actually go off the chart if you extend them to current temperatures:
        
        
        
        As for "Mike's Nature trick", that situation is the case where the decline is not a decline in temperatures but a decline in tree ring growth's response to temperature. So it's entirely appropriate to not use tree rings as a proxy for temperature after 1960 when some other factor is clearly influencing tree ring growth. More on tree ring divergence...
125199. HumanityRules at 14:45 PM on 20 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        #34 response EXACTLY!! It does appear though that in your article you are dismissing solar variance because the relationship breaks down after 1975. There is nothing in this article any stronger or weaker than the "issue of mid-century cooling" by the skeptics. For that reason you should dismiss it. Riccardo Nobody suggested John was trying to fool us. But there is no reason to believe, like the rest of us mortals, that he's infallable. David Horton I have looked at the graph it starts lower and ends higher. If you put a single linear trend line through it I'm fairly sure that the slope would be positive. If you look at some of the links John has provided or google it you'll see that there is an upward trend since records began in the 1600's
        Response: Mid-century cooling is a good example of the logic used in this article. In recent decades, the sun has been cooling. Therefore, the logical conclusion is that the sun is not contributing any warming over this period.
        
        The same logic applies to mid-century cooling. At that time, CO2 levels were rising. Therefore, the logical conclusion is that CO2 was not contributing any cooling over this period.
        
        CO2 did not cause mid-century cooling. Other forcings must have been responsible.
        
        The sun is not causing current global warming. Other forcings must be responsible.
125200. David Horton at 13:09 PM on 20 January 2010
        2009 - 2nd hottest year on record while sun is coolest in a century
        #35 "TSI going up since 1880" - have you actually looked at the graphs?

Prev  2496  2497  2498  2499  2500  2501  2502  2503  2504  2505  2506  2507  2508  2509  2510  2511  Next