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Comments 124901 to 124950:

124901. carrot eater at 09:52 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron: I will refrain from commenting on the new US homogenisation method until I'm sure I understand it. I'll just say it's been updated, so if you haven't, then check out the description. This is yet another Menne et al (2009), this one in Journal of Climate. "Homogenization of Temperature Series via Pairwise Comparisons" In terms of whether there are large areas where there are no surrounding rural stations within a reasonable radius: I don't think you'll be able to find such a region. Anyway, we've seen so many analyses that would show that UHI is not contaminating the overall US mean - datasets that only include rural stations, comparisons of calm and windy nights, etc, etc. There's probably good articles on this site to refer you to other papers on that. Be careful; the station rankings here don't necessarily have anything to do with urban warming. In terms of whether there are enough 'good' sites to correct the 'bad', Menne (2010) shows that nicely. They show good and bad, unadjusted, adjusted only for TOB, and with all adjustments. You can see that the main correction in the 'good' is due to TOB, which does not use neighboring stations. For the most part, the neighbor-based correction takes the 'bad' and makes them converge with the 'good'. So that makes sense.
124902. Riccardo at 09:48 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron2000, you do not need to be hundreds of miles away from a even a large town to get meaningfull reading. Central Park in New York, for example, is almost free of the UHI effect. There's plenty of room in the west coast or Nevada or whatever to get meaningfull readings.
124903. Ed Davies at 09:39 AM on 30 January 2010
        Guest post in Guardian on microsite influences
        RSVP: "It would be nice to know what the measurement accuracy of these systems have on their own. If, for instance, the Earth's temperature was actually rising 0.10 degree per decade, you would need at least +-.05 degrees to even begin to substantial this." If the results are obtained using many measurements from a each of a large number of instruments then the overall trend can be found to much higher precision than the accuracy of individual instruments (if there's no systematic bias in the errors, of course, which is the whole point of the article). You could easily see a 0.1°C/decade increase using only a few dozen thermometers which only had a resolution of 1°C using one measurement from each for each of the 3652 or so days in a decade.
124904. Riccardo at 09:16 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        It looks like a partial account of the difference between the two composites. Ignoring the acrim gap problem, ignoring the problem of the definition of the maximum of solar cycle 21 (NIMBUS 7 before the start of ACRIM-I), dismiss it like a choice of pro- vs anti- AGW theory and simply state that acrim is "most credible" while pmod "does not represent the most likely interpretation" is clearly a biased interpretation. The ACRIM team itself aknowledge the problems while you, despite your nick (that sounds like advocating one side) do not.
124905. Jesús Rosino at 09:12 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        acrim, I also thought that they may have used the acrim composite. However, it's flase that it is "the most credible compilation". All the intdependent proxies of solar activity have backed up the PMOD composite. In any case, the difference is insignificant. http://www.skepticalscience.com/acrim-pmod-sun-getting-hotter.htm http://tamino.wordpress.com/2007/01/22/here-comes-the-sun/ http://tamino.wordpress.com/2007/01/24/here-comes-the-sun-part-2/ http://tamino.wordpress.com/2007/07/12/there-goes-the-sun/ http://tamino.wordpress.com/2007/07/24/pmod-vs-acrim http://tamino.wordpress.com/2007/07/27/pmod-vs-acrim-part-2 http://www.realclimate.org/index.php/archives/2009/05/acrim-vs-pmod
124906. sbarron2000 at 09:03 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Interesting. The "difference in means test" is what we're talking about? That seems like it would work great in an area that had one urbanizing site surrounded by several (up to 10) rural sites. But what happens if 7 of the 10 neighboring sites are also seeing some urbanization? There are a lot of (Figure 1, Menne 2010) in areas that have seen rapid poplation growth over the past 30 years (the entire west coast, Arizona, Nevada, etc.). I wonder how effective the differences in mean test works in states where there has been wide spread population growth. It might make finding neighboring sites that are uneffected by their own gradual urbanization increase difficult. And since it doesn't appear there is any specific correction for that situation, gradual locality warming could go unadjusted. And given that only 71 of the 400+ sites were actually deemed "good," There aren't many good sites correcting for the bad sites differing means. Or maybe I'm totally off base? :-)
124907. CoalGeologist at 09:00 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        re: stevecarsonr (Post #3): Your comment and John's reply, address one of the most difficult and frustrating aspects of the climate change debate. I don't believe it's possible to understand the scientific issues without understanding the difference between skepticism, which is based on scientific reasoning, and denialism, which is based on ideology, yet even using these terms "raises hackles" and causes animosity. But unless one recognizes that denialism is a) real and b) not about scientific evidence, it will be very difficult to ever sort out truth from fiction. I know too many people—decent, intelligent people—who have effectively been sucked down into the vortex of "denialism world", where they give credence to arguments that are not scientifically defensible, and can become fixated on "debunking the myth" of anthropogenic global warming. No matter how sincere their intentions initially were, or are currently are, I do not believe they retain the ability to recognize how biased their approach to the topic has become. One colleague of mine, with the very best of intentions, sent me a copy of Ian Plimer's book as a Christmas gift, hoping that it would help me grasp the truth about climate change. How can I convey to him how biased and misleading the science content is without offending him, which I really don't want to do? I agree that there are many people who are legitimately confused and sincerely want to understand the scientific evidence, which is why I so resent the denialist approach. Denialism doesn't increase understanding. Rather it sews confusion. Worse, it nurtures suspicion and mistrust. The issue here is not about being "smart" or "dumb". Rather it's about the ability to recognize bias. This is often very difficult. Understanding the scientific evidence can be challenging enough but when you add in all the bogus arguments and faulty reasoning of denialism, a topic that starts out as merely “challenging” can quickly become overwhelmingly confusing. A key question is whether we sincerely want to understand the science, or whether we are simply looking for validation of what we would like to be true. It's so easy to do the latter, while believing we are doing the former. I have no other way of explaining “skepticism” among many (although certainly not all!) of my colleagues in the fossil energy industry. Yet how can I possibly say this without alienating the very people I would most like to reach? I don't have an answer.
124908. Berényi Péter at 08:32 AM on 30 January 2010
        Peer reviewed impacts of global warming
        doug, as soon as solar power becomes cheaper than other sources, it would not need government subvention on taxpayers' money and would replace traditional power plants soon. However, a level playground is a must, otherwise economy would suffer. Until that time it may make sense (on increased cost, not exactly for the poor) if there is no power grid nearby. Otherwise the best investment right now is to R&D, not installation. It is not just about solar panels, battery packs are of more concern (and pricey). Earth is round, sun is not up all the time.
124909. acrim at 08:32 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        Re your statement: "As direct measurements of solar activity show solar output decreasing since 1980, I was interested to see where his data came from but the graph was gone before I could locate the reference." He was quoting the findings of the ACRIM Compsite total solar irradiance (TSI) - the most credible compilation of satellite TSI observations, which shows a net upward trend during the past 30+ years. The ACRIM Composite uses the results of satellite experiments published by their science teams without alteration. You are familiar with the PMOD Composite TSI which shows a slight downward trend over the past 30 years of TSI observations. Unfortunately the makers of the PMOD Composite made unjustifiable alterations of the published satellite data to conform it to the approximate predictions of TSI proxy models. Use of the PMOD Composite is useful to the AGW GHG hypothesis because it makes solar variability a less likely competitor of Anthropogenic GHG climate change. However the PMOD does not represent the most likely interpretation of the extant satellite TSI database. For a discussion of this and related topics see the ACRIM website: acrim.com.
124910. Tom Dayton at 07:33 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Thanks for the correction and detail, carrot eater!
124911. stevecarsonr at 07:18 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        Jim Eager at 04:11 AM: I don't understand that claim. I thought it was convention to look at TOA results as being equal because it makes it easier to compare the relative forcings. At some point you are correct, but 1W/m^2 of solar insolation is not the same as 1W/m^2 at TOA due to increases GHG. How much absorption of S/W radiation by the atmosphere? And what profile? How does the atmosphere respond to this absorption? What are the changes in the atmosphere as a result? How much absorption by the surface? And due to the different albedos of different surface materials, the heating will be different at different locations, causing temperature differentials and so on. Compare that with more long wave forcing. A different surface absorption (geographically). A different atmospheric profile. Different effects on the atmosphere. Perhaps it all "comes out in the wash" and perhaps someone has already demonstrated that it is irrelevant what source?
124912. carrot eater at 06:33 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron2000: In asking about gradual changes at a site, you are asking the correct question. Gradual changes affect the trend, and require attention. I refer you to Menne, Williams and Vose (2009) in BAMS. They discuss this problem, and find that their method can handle it; they show an example for Reno, Nevada in Fig 8. This adjustment method is new, and I haven't yet digested how it works, or why it's better than the previous.
        Response: Here's a direct link to the 2009 Menne paper - Menne 2009 - this is where they also discuss the influence of the switch from CRS to MMTS.
124913. carrot eater at 06:24 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Tom Dayton: I may be reading you incorrectly, but you appear to say that the bias due to switching from liquid thermometers to MMTS stations was recently discovered. It was not. It is mentioned as early as 1991. See Quayle et al, "Effects of Recent Thermometer Changes in the Cooperative Station Network." In that paper, it was found that the MMTS stations reported lower max temps and higher min temps, and it gave some possible reasons why. Menne (2009) revisited the issue, and Menne (2010) suggests that the adjustment may not be complete, leaving behind a slight cooling bias in the adjusted MMTS figures. That would take further work to confirm. I hope I'm correct on that myself, but hopefully that is of help.
124914. Doug Bostrom at 06:13 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron2000 at 04:40 AM on 30 January, 2010 "Further, what about the classification of a station by type? Is that historical at all, or are stations considered to have always been the type classified when they were evaluated by surfacestations.org? " If it had been designed for scientific research, Watts' survey could have really helped with quantifying the questions you ask. Unfortunately the information solicited includes little that would have made all the effort performed by volunteers more useful. All sorts of data including development density changes, prevailing winds, etc. could have been gathered by volunteers if they had been competently directed, provided with specific and unambiguous instruction as well as a carefully crafted collection system. surfacestation.org has instructions and data collection sheets on the site. Collection sheet: http://www.surfacestations.org/downloads/StationSurvey_form.doc As you can see, normalizing the results of the questionnaire would be hugely labor intensive given the open-ended nature of the response solicitations. The whole effort appears to have been about generating embarrassing photographs. All the same, Menne was able to salvage something from Watts' disaster; photographs did allow at least a rough qualitative division of locations. So for Watts it was temporarily at least a PR win but permanently a science botch. If he had approached scientists with a proposal for collaboration instead of wasting himself flinging baseless charges of incompetence and corruption maybe he would not have wasted so many people's time. Nice that Menne was able to tease out what was useful from the wreckage.
124915. jpark at 06:12 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Sorry I meant 'sunk' in terms of public opinion and policy not in terms of science.
124916. jpark at 06:11 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        A bit off topic but it did make me laugh! http://wattsupwiththat.com/2010/01/29/diverging-views/#more-15833 And this line jumped out "the land based extrapolation actually turned those sea based cells more than 3C hotter." To go back to the topic - if this is the best info we have then AGW is sunk. I am learning all about PC analysis by the way - really trying to get educated!
124917. Philippe Chantreau at 05:48 AM on 30 January 2010
        Guest post in Guardian on microsite influences
        Meanwhile, we are seeing just in the past week significant numbers of record high temperatures at the highest latitudes of the continental US. I guess RSVP must be living in the wrong neighborhood. http://mapcenter.hamweather.com/records/7day/us.html?c=maxtemp,mintemp,lowmax,highmin&s=20090913&e=20090913
124918. sbarron2000 at 04:40 AM on 30 January 2010
        On the reliability of the U.S. Surface Temperature Record
        How would a slow urban build-up around a rural temp. station be treated via microsite and UHI adjustments? Are these adjustments historical at all, other than major events like changing instruments, or locations? Basically, if a site was rural at one time, and over time has become urban, is the UHI adjustment applied at increasing levels over the peiod of this transformation, or is it just applied all at once? Further, what about the classification of a station by type? Is that historical at all, or are stations considered to have always been the type classified when they were evaluated by surfacestations.org?
        Response:

        "How would a slow urban build-up around a rural temp. station be treated via microsite and UHI adjustments?"
        
        This is a good question and is addressed in Urbanization effects in large-scale temperature records, with an emphasis on China (Jones et al 2008) - I give a summary of the paper's results here.

        Re the classification of stations, the NOAA have classified their stations also - Menne 2010 performs their analysis with the surfacestations.org classifications and their own.

124919. Doug Bostrom at 04:16 AM on 30 January 2010
        Peer reviewed impacts of global warming
        Berényi Péter at 01:02 AM on 30 January, 2010 "Solar power is hopeless until..." Actually Africa is a place where little teeny-tiny solar panels have made a huge difference in a lot of folks' lives. There is no power grid at all over much of the continent, a problem for industry and shocking for those of us who grew up with electricity available in arbitrarily large quantities. Yet there are literally millions of persons in Africa who are able to enjoy a modicum of lighting, radio broadcast reception, and a few other small amenities thanks to the common use of a ~15W panels attached to batteries. Selling parts for these is a thriving industry. Benefits include being able to read, burning deaths avoided, money saved by not purchasing kerosene. On the other hand, when you've grown up with grid power, a different story. 15W is not going to make most of us happy, but Africa does afford an interesting perspective on how little electricity is required to obtain a large benefit.
124920. Riccardo at 04:14 AM on 30 January 2010
        Peer reviewed impacts of global warming
        Bruce Cooke, probably 4000 years ago it was not hotter than now. A proposed mechanism for the drying of the Sahara is a shift of the monsoon due to the changing earth tilt angle; the reduced summer insolation was not strong enough to pull the monsoon north.
124921. Jim Eager at 04:11 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        fydijkstra, climate sensitivity does not depend on the source of the forcing, only on the magnitude of the forcing. A forcing of 1 watt/meter sq will produce the same warming plus feedbacks regardless of if it is due to an increase in greenhouse gases or an increase in insolation. The climate does not pick and choose which forcings it will respond to and by how much.
124922. Jim Eager at 03:53 AM on 30 January 2010
        The upcoming ice age has been postponed indefinitely
        But neither a Toba/Yellowstone nor a Siberian/Deccan traps event are happening right now, so Plimer's point is just another distraction.
124923. Berényi Péter at 02:01 AM on 30 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Charlie A at 12:52 PM on 28 January, 2010 "I have found a peer reviewed paper from Geophysical Research Letters that supports the AR4 findings!" The peer reviewed paper in Geophysical Research Letters is this one: GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L22503, doi:10.1029/2008GL035556, 2008 Mass loss on Himalayan glacier endangers water resources Natalie M. Kehrwald, Lonnie G. Thompson, Yao Tandong, Ellen Mosley-Thompson, Ulrich Schotterer, Vasily Alfimov, Ju¨rg Beer, Jost Eikenberg, and Mary E. Davis Received 1 August 2008; revised 24 September 2008; accepted 21 October 2008; published 22 November 2008. http://bprc.osu.edu/Icecore/Kehrwald%20et%20al%202008.pdf It actually contains the phrase "The surface area of glaciers across the TP is projected to decrease from 500,000 km2 measured in 1995 to 100,000 km2 in 2030 [Cruz et al., 2007]" Cruz et al., 2007 is of course IPCC AR4, WG II Report, chapter 10. No problem, AR4 was subject to peer review, even if a slightly redefined version of it. Cruz, R. V., H. Harasawa, M. Lal, S. Wu, Y. Anokhin, B. Punsalmaa, Y. Honda, M. Jafari, C. Li, and N. Huu Ninh (2007) Asia, in Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by M. L. Parry et al., pp. 469–506, Cambridge Univ. Press, Cambridge, U. K. http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter10.pdf The GRL quote is based on an IPCC/AR4 Figure 10.4 caption (Hotspots of key future climate impacts and vulnerabilities in Asia), which reads "Tibetan Plateau glaciers of 4 km in length are projected to disappear with 3°C temperature rise and no change in precipitation. If current warming rates are maintained, glaciers located over Tibetan Plateau are likely to shrink at very rapid rates from 500,000 km2 in 1995 to 100,000 km2 by the 2030s. [10.4.4.3,10.6.2]" The Kehrwald at al. quote is an abridged version of it. They omitted the generous 3°C temperature thing along with the restriction "no change in precipitation", and the tiny letter "s" after "2030" (it may be the source of the IPCC:2035 - NASA:2030 transition). BTW, the "glaciers of 4 km in length" is also omitted, a pity, for it is absolutely mysterious. Otherwise it is correct. To tell the truth, I would like to have a word or two with the anon referees of GRL who let this crap through. But IPCC GR4 Himalayan glacier claim got supported by a peer reviewed paper, even if it was done in retrospect, based on the very report to be supported. New Age science is supposed to work this way, isn't it?
124924. Ned at 01:52 AM on 30 January 2010
        The upcoming ice age has been postponed indefinitely
        I think there's some confusion there between (a) a huge explosive event at, say, Yellowstone, which could potentially inject a lot of aerosols into the stratosphere, and (b) a broad-scale, multi-century flood basalt event like the Siberian traps or Deccan traps, which would outgas a lot of CO2. Yes they're both catastrophic volcanism but the climate impacts are quite different.
124925. Berényi Péter at 01:02 AM on 30 January 2010
        Peer reviewed impacts of global warming
        canbanjo at 10:36 AM on 28 January, 2010 "what hope does africa have?" None. Solar power is hopeless until solar panel prices drop below that of leaves, a goal achievable only by self replicating systems. It requires brand new technology not developed yet.
124926. CoalGeologist at 00:54 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        MarkJ (Post #1), Here's one geologist's perspective (mine!). The argument can be broken down like this: 1) There is strong geologic evidence that surface temperatures have varied significantly in the Earth's past, both up and down. One of the indicators of this is the presence or absence of polar ice caps. (We can see evidence of glaciers in the sedimentary rock record, so we know when ice caps have been here in the past). Therefore, we know that surface temperature has changed a lot, and is sensitive to something... But what?? 2) Evidence shows that a number of factors can drive changes in temperature, including variability in Earth's orbit, variations in solar emissions, changes in atmospheric composition, changes in albedo, etc.; HOWEVER!.. The geologic record shows that elevated CO2 consistently shows up "at the scene of the crime" when the Earth has experienced past episodes of warming (For an informative, entertaining summary of this, listen to geologist Richard Alley's lecture from the recent AGU meeting. It will take an hour, and may be a bit technical, but I hope you'll find it worthwhile. http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml 3) But even if periods of high temperatures are always associated with high CO2, how do we know which caused which? This one's harder to answer in just a few sentences, so you'll have to do some homework, but you can think of increasing atmospheric CO2 as being like adding more blankets on to your bed on a cold night. The more blankets you add, the warmer the bottom blanket will be, and the cooler the top blanket will be. That's why adding more CO2 keeps causing more warming, even though the absorption bands are saturated. 4) There's one final argument although it's a bit weaker: The CO2 model fits most of the evidence, and right now we have no other way to explain these past temperature changes other than CO2. The same argument holds for late 20th Century warming! In contrast, Lord Monckton claims that the atmosphere is self-regulating, and that there are negative feedbacks that prevent the atmosphere from getting warmer when you add CO2. Monckton is just smart enough to seem like he knows what he's talking about, but actual climate scientists see many flaws in his arguments. Monckton and Plimer may mean well, and might even believe what they say (?), but in the end science is not on their side. A Little Knowledge + A Lot of Bias = A Dangerous Thing
124927. Marcus at 00:03 AM on 30 January 2010
        The upcoming ice age has been postponed indefinitely
        Actually, Chris, they reckon something similar happened around 4,000 years ago-a slowing of the Gulf Stream caused an extreme cool period in Europe whilst causing a major drought to Egypt & the Middle East-the drought which brought down the Egyptian Old Kingdom.
124928. Ed Davies at 00:01 AM on 30 January 2010
        Lessons from the Monckton/Plimer debate
        fydijkstra: "...and Monckton says that the sensitivity of the climate for greenhouse gasses is much smaller than IPCC claims." The point is, though, that the sensitivity is determined by the feedback effects resulting from the temperature change due to a particular forcing irrespective of the forcing's cause, whether it be changes in the solar irradiance, the shape of the Earth's orbit or the composition of the atmosphere.
124929. Marcus at 00:01 AM on 30 January 2010
        The upcoming ice age has been postponed indefinitely
        Ubique. From everything I've read on Yellowstone, if it erupts it won't cause warming-it will cause extreme, localized cooling (not unlike a nuclear winter). If it blows, you can pretty much say goodbye to the bulk of the human & animal population of North America for the next few centuries at least. However, just like the possibility of rogue asteroids, it would be extremely foolish to do nothing to prevent man-made global warming just because of the 1:1,000,000 chance of a super-volcano explosion.
124930. BC at 23:55 PM on 29 January 2010
        Peer reviewed impacts of global warming
        The Sahara was more fertile before about 4K years ago when the temperature was hotter. Is it possible that it will become so again when global warming kicks in?
124931. Berényi Péter at 23:03 PM on 29 January 2010
        Guest post in Guardian on microsite influences
        Could anyone provide a pointer to the literature of "data homogenization" as a statistical procedure? I mean the kind of study that would discuss it on its own right, independent of Climate Science. I looked hard, but could come up with nothing. There is something called data homogenization used in data warehousing, but in the absence of metadata it relies heavily on AI technologies like pattern recognition. It is not meant to be used to produce "objective" datasets, just hints. In other words it is woodoo magic, not a tool for science. BTW, Menne at al 2010 do depend on data homogenization. http://www1.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2010.pdf
124932. Arkadiusz Semczyszak at 22:55 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        5. 4. Exxon - he depends only on the same subsidies for CCS as well as in Europe. If current warming would, for instance, such as the Older Peron, the money is better spent on protection against transgression of the sea.
124933. Marcus at 22:50 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        fydijkstra, either climate *is* sensitive to forcing or it isn't-you can't have an each way bet, as Monctkon chooses to have. The properties of the various greenhouse gases has been established over more than a century-especially its ability to capture Long-wave infrared radiation (heat). To try & claim otherwise is to refute more than a century of chemistry & physics. It comes down to this simple question-average global temperatures have risen by around +0.5 degrees over the last 30 years, yet solar activity has declined by around an average of 0.3 watts/meter squared per decade over that similar time period. So where is the extra heat coming from? Until so-called skeptics can produce a valid, alternative theory for the warming trend, then they really lack any credibility!
124934. Arkadiusz Semczyszak at 22:41 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        3. A propos CHYŁEK - is not a skeptic, at most: "semi" skeptic. Skeptics believe, that the former: first followed the rise in temperature, then CO2 (soil bacteria and ocean heterotrophic bacteria - they are to blame), but CO2 - never had a significant effect on temperature. Water vapor, feedback is always neutralize majority of RF CO2.
124935. Ubique at 22:40 PM on 29 January 2010
        The upcoming ice age has been postponed indefinitely
        John, 'The burp from one volcanic eruption would overpower all the CO2 humans have ever emitted'. The numbers say otherwise as does the CO2 record which shows not a blip during the 20th Century's largest volcanic eruptions. Do you think he might be referring to the eruption of a super volcano – such as the one under Yellowstone National Park – rather than one like Mt St Helens in British Columbia in Canada? I lived in Canada down wind of that one when it blew and it certainly had an effect upon the climate locally. When Yellowstone blows (overdue they tell us) the impact will be global.
124936. fydijkstra at 22:07 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        One afterthought: Monckton does not say that the climate has a low sensitivity. He only rejects the hight sensitivity for CO2. Solar magnetism, cosmic rays, and orbital forces, that may have caused past climate changes may have much more influence than IPCC admits.
124937. chris at 22:05 PM on 29 January 2010
        The upcoming ice age has been postponed indefinitely
        re #35 The temperature minimum at the Maunder minimum has been examined in some detail. The solar irradiance contribution from suppressed solar activity is considered to have been as much as 0.2 oC globally averaged compared to the mid-20th century level (top article and your own analysis). The Maunder Minimum (MM) and the Little Ice Age (LIA)was also a period of considerable volcanic activity, and this is expected to suppress the temperature (globally-averaged) by around another 0.1 oC. This can pretty much cover the full extent of the MM/LIA cooling when considering a global (or even N. hemisphere average). For example, the most variable paleoreconstruction covering the last ~ 2000 years [*] indicates that the "baseline" (N hemisphere-averaged) temperature was around -0.4 oC (compared to mid-20th century) for several hundred years before the Medieval warm Period (MWP). NH temp rose to ~ 0 oC (relative to mid-20th century) at the height of the MWP around 1000 AD, and dropped to around -0.7 oC at the depths of the MM/LIA (see Figure 2 of Moberg et al [*]): [****] A. Moberg et al. (2005) Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data Nature 433, 613-617 coast.gkss.de/staff/storch/pdf/moberg.nature.0502.pdf Since global (hemispherically-averaged temperature changes are concentrated over land and often "focussed" in the high N. latitudes, a temperature drop of -0.3oC, can equate to a much larger temperature drop (-1 oC or more) in Western Europe where the LIA is documented. Likewise there is evidence that the Gulf Stream intensity was reduced during the period of the LIA (perhaps in response to reduced solar forcing) [**], and this is likely to have reinforced a gradient of cooling in the N. hemisphere with the Western Europe fringes getting the largest cooling whack...thus those pretty pictures of revellers on the frozen Thames, and hunters in the snow in Holland by Breugel... [**] Lund DC (2006) Gulf Stream density structure and transport during the past millennium Nature 444, 601-604 http://www.nature.com/nature/journal/v444/n7119/abs/nature05277.html
124938. fydijkstra at 22:03 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        Monckton's and Plimer's opinions are not contradictory. Plimer argues that the climate has changed very often in the past, due to other reasons than greenhouse gasses, and Monckton says that the sensitivity of the climate for greenhouse gasses is much smaller than IPCC claims. These two arguments are complementary.
124939. Arkadiusz Semczyszak at 21:49 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        1. During volcanic eruptions (very large) amount of CO2 accumulated in the atmosphere falls sharply ("Sinks for anthropogenic carbon", J.L. Sarmiento and Gruber N.; 2002, page 32, Fig. 3.). Accumulated amount of CO2 in the atmosphere is highly dependent on temperature changes -http://www.jennifermarohasy.com/blog/archives/Jan%20Pompe_co2%20and%20temp2.gif. Particularly NH temperature. So they can only respond quickly to natural sources of emissions - soil bacteria (I recall the experiment Biosphere 2). Volcanic aerosol = less SI for plants = less photosynthesis = fall NPP = more CO2 in the atmosphere ... 2. Former historic temperature changes were much more violent, than the current (f. e.: "Abrupt tropical climate change: Past and present", L. G. Thompson; 2006 -http://www.pnas.org/content/103/28/10536/F4.large.jpg).
124940. LauraM at 21:22 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        To MattJ (6) Succinctly put. Scientists need to budget time and resources now to learn PR and new communication skills. Or perhaps use their endless riches in funding (not) to hire people already with these skills, like Exxon did.
124941. Riccardo at 21:11 PM on 29 January 2010
        The hockey stick divergence problem
        MattJ, as far as i know the final word on the divergence problem has not been said. Anyone is open to the possibility that the same problem showed up in the past but at the moment there's no evidence of it given the overall agreement of many different proxies.
124942. Riccardo at 21:01 PM on 29 January 2010
        There's no empirical evidence
        samantha, it's a more than two years old story and has been refuted so many times that there should be no need to pull it back. Give a quick look here and at the links provided.
124943. MattJ at 20:53 PM on 29 January 2010
        The hockey stick divergence problem
        A large portion of the article, and many of the comments are devoted to defending the thesis that the 'divergence' is man-made, and that there is no attempted cover-up. Well and good. I believe this thesis is established. But what I would like to see and do not see, is proof that similar divergences could not happen in the past. Simply proving that today's divergence is man-made does not prove this, though the suggestion is rather strong. At some point, the skeptics will think to ask this, once they figure out there are not making much headway with their false accusations of cover-ups. So it is important to do. The hard part, of course, is figuring out what kind and level of proof is even possible. I don't know trees well enough to come up with helpful suggestions there.
124944. MattJ at 20:45 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        Your last sentence sums it up very well: "Two skeptic arguments can contradict each other, even on the same debating stage, so long as the common enemy of man-made global warming is refuted." This illustrates the difference between the scientist, the politician, and the general public. The scientist has put many years of educational effort in to learning the importance of logical reasoning at many levels, the general public has never done this. So of course, they are highly susceptible to Monckton's style of crass manipulation, they even welcome it. But here is the real problem: scientists well aware of the threat of AGW have never taken a scientific approach to understanding how the general public forms opinions, and so is outmanouvered by professional deceivers like Monckton every time. We are running out of time to close this PR gap. We may have run out already.
124945. ScaredAmoeba at 20:44 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        What the USGS says about volcanoes and gases Comparison of CO2 emissions from volcanoes vs. human activities. Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002) http://volcanoes.usgs.gov/hazards/gas/index.php
124946. ScaredAmoeba at 20:38 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        John, I'm sure you're aware of it, but Plimer has been ambushed, about his claims about volcanoes and CO2 and shown to be dishonest, but he prevaricated and tried very hard to distract and change the subject. Plimer has no shame. Partial [edited] transcipt GEORGE MONBIOT: .... Take, for example, his claim that human beings produce more carbon dioxide than volcanoes. Now, the US geological survey shows that human beings - sorry, he suggests that volcanoes produce more carbon dioxide than human beings. The US geological survey shows that human beings produce 130 times more carbon dioxide than volcanoes. And yet again and again, however many times it is pointed out to him, Ian keeps reporting this straightforward fraud, this fabrication that volcanoes produce more CO2. ... IAN PLIMER: Well I'm very heartened that a journalist is correcting me on my geology. Now Mr Monbiot wrote to me when I asked him some questions of science and said he was not qualified to answer these questions of science. So he's a journalist and he's asking me a scientific question. He has not read this book ... .... IAN PLIMER: Well, let me make two points on this. On the chapter called Earth I talk about two volcanoes. One are the terrestrial volcanoes, which is the USGS reports on emissions of carbon dioxide, but more than 85 per cent of the world's volcanoes we do not measure, we do not see, these are submarine volcanoes that release carbon dioxide and we deduce from the chemistry of the rocks how much carbon dioxide is released. TONY JONES: Can I ask you a question about that, if you don't mind? Because one British journalist whom you quoted those exact figures to went back to the US geological survey after you told him about this 85 per cent figure, and asked he them to confirm their claim that actually 130 times the amount of CO2 is produced by man than volcanoes. The volcanologist Dr Terrance Gerlach confirmed that figure and said furthermore that in their counting they count the undersea volcanoes. So your response to that. IAN PLIMER: My response is that there are 220,000 undersea volcanoes that we know about. There's 64,000 kilometres of undersea volcanoes which we do ... GEORGE MONBIOT: Which they have counted. IAN PLIMER: It is the height of bad manners to interrupt. Please restrain yourself. And we have 64,000 kilometres of volcanoes in submarine environments with massive super volcanoes there. We do not measure them. And the figures that I have used are deduced from the chemistry of rocks which erupt on the sea floor. TONY JONES: OK. Now, that's that point dealt with. George Monbiot, a quick response to that and then we'll move on to other questions. GEORGE MONBIOT: Yeah, sure. I mean, it's, again, straightforward fabrication. Ian produces no new evidence to suggest that the USGS figures are wrong. He keeps citing this statement that they don't include submarine volcanoes. It's been pointed out to him many, many times that the USGS figures do include submarine volcanoes. And actually, it's the height of bad manners Professor Plimer to lie on national television about something that you know to be plain wrong. You get the flavour. The transcript is at: http://www.abc.net.au/lateline/content/2009/s2772906.htm
124947. stevecarsonr at 20:33 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        I saw Monckton being interviewed by Ben Cubby on smh.com.au and he was very funny - mostly from making such outrageous claims. I think it's in part intentional. As you say, he knows how to work the crowd. A comment on your statement: "In a sense, this perfectly encapsulates the skeptic movement as a whole. Global warming skepticism isn't about furthering scientific understanding but proving that humans can't be causing global warming." Let's assume you are right and have summarized the "movement". I'm fairly new to your website so feel free to tell me to not bother with these kind of comments I'm about to make.. they aren't meant to be critical.. It seems like you have put a lot of time into creating the site and a lot of the material is specifically aimed at skeptics. So you care about educating "the skeptic movement", which is wonderful. If it's really aimed at that "movement" I think you will be doing your hard work a disservice by putting down the people you want to help. There are a lot of people out there really trying to figure stuff out. But they don't have physics degrees, have never read an undergrad book on radiative physics and have only a very hazy idea of "the scientific method". So pretty much anything can sound authoritative. One way to put people off is to tell them how dumb they are. Much worse - tell them their ethics and motives are flawed. They will go and hang out somewhere they feel more comfortable. And so your hard work will only achieve 20% of its potential.
        Response: I appreciate your comments. I always try to avoid alienating people by characterisation and I didn't quite achieve that goal this time around. I've tweaked the wording of the final paragraph so that it addresses the arguments, not the people.
124948. David Horton at 20:03 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        Yes, excellent point John. I saw Monckton on the ABC with Ben McNeil. The classic moment was when Monckton turned to Ben and said "of course you are not an expert in climate science". He then waffled on about sensitivity referring to Lindzen with no chance to be contradicted (and in any case the contradiction is too complicated for a lay audience, especially in the time allowed on a current affairs show). Very clever tactic. And I would like to ask Plimer why on Earth he believes that climate change in the past contradicts AGW now. Does he really believe that a rapid change occurring over the last 30-40 years is the result of the same natural causes as the slow geological changes? And if so, why? But I'm sure he wouldn't answer (which is his clever technique).
124949. MarkJ at 20:02 PM on 29 January 2010
        Lessons from the Monckton/Plimer debate
        Good morning, I was wondering if you could elaborate on how the the 2 skeptic positions of natural variability and low climate sensitivity contradict each other? Seems to me that both arguments say CO2 does not play as nearly a large role in climate as the majority of scientists argue.
        Response: Good evening (here in Brisbane at least). I'll try coming at it from another angle in the hope that it clarifies the science more. As Barry Brook explained today (after Plimer dodged my question), climate doesn't change by magic. It changes because it's forced to change. The forcing that changes climate is changes in the planet's energy balance - when the planet is accumulating heat or losing heat. This energy imbalance is also called radiative forcing.
        
        So a key question with climate is how sensitive is our climate to radiative forcing? For example, if you doubled atmospheric carbon dioxide which has a radiative forcing of 3.7 W/m², what is the global change in temperature? The extra heat causes a direct surface warming of around 1.1°C. But then feedbacks come into play. The warming causes more evaporation which puts water vapor into the atmosphere - the greenhouse effect of the extra water vapor has an amplifying effect. Ice melts, lowering the Earth's albedo which causes further warming. There are also potential negative feedbacks - if clouds increase, this raises the Earth's albedo which has a cooling effect. So when you put it all together, does the planet have net positive feedback (which would mean a higher climate sensitivity) or a net negative feedback (lower climate sensitivity).
        
        We work out climate sensitivity by looking at past climate change. We work out what the forcings were that drove climate, we use proxies to determine how much temperature changed and from this, we calculate climate sensitivity. Often scientists look at periods of great change such as the Last Glacial Maximum where the earth came out of an ice age. And what these analyses find is that our climate has high sensitivity. It has net positive feedback. The great climate changes observed in the past are not possible without high climate sensitivity.
        
        So when Ian Plimer cites past climate change, he's citing evidence for high climate sensitivity. This is in direct contradiction to Monckton's position that our climate has low sensitivity.
124950. Tom Dayton at 17:56 PM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Leo G, now to relate my explanation to the light bulb analogy: The replacement of the instruments is analogous to replacing the thermometer in the room with the light bulb, when the new thermometer reports slightly cooler temperatures than the previous thermometer did. The resulting cooler measurements have nothing to do with the light bulb. The poor siting of the new instruments was not the cause of the cooling. The poor siting was merely an accidental clue to the discovery that the new instruments were cooler. And why didn't the anomaly computation compensate for this artificial coolness? Because the situation changed. An anomaly computation compensates only for a constant bias. In this case the bias changed with the instrument replacement, but the anomaly continued to be computed off of the same baseline, so of course the anomaly accurately reflected the new bias. Use of anomalies does not correct all kinds of errors. Other adjustments are carefully made to compensate for changes in instrument, instrument type, specific location, and other situations.

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