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Comments 124801 to 124850:

124801. Tom Dayton at 08:11 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        padruig, that was just mentioned by dhogaza.
124802. Leo G at 08:08 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Doug @ 30 - "the lightbulb in the room" mind exercise. (Doug, may I change this a bit, and just for argument sake, I want the light to have a thick metal reflector on it to absorb some of the lights heat energy (yes I'm using an incandescent bulb!), so as to compare to an air field tarmac situation OK?) If the light bulb gets the sensor to read say 17C when the ambient room temp is 16C, then no anomaly will appear until the ambient room temp gets above 17C correct? Take another room also at 16C but no light bulb. With central heating, and both rooms were raised to 18C, then light bulb room would only show a 1C anomaly, whilst no light bulb room would show a 2C anomaly, correct? So though we know in fact that there is a true 2C anomaly, by averaging the two rooms anomalies we only get 1.5C so are thus under reporting by a full 1/2C. So is this what Menne is saying about a cooling bias? But wait, what if at night time, before going to bed, I turned the heat down in my house (again the rooms are at 16C, and sensor one reads 17C, sensor two 16C). Just for argument sake the rooms both loose 1/2C per hour and just for argument, the heat is lowered for 8 hours. Now the room with the sensor that has no light at the time the heat comes back on is reading 12C, but the sensor in the room with the light and heavy metal reflector is at about 13C (yes I grabbed this one out of thin air, but you get my point I hope). Now the combination of both rooms will show a bias towards warmth at about 1/2C. Of course this is a very simple thought experiment, but I hope you get my drift. Sightings really can make a difference. I don’t even want to try to think about a station getting the heat from an air conditioner during the day, then having a large temp drop during that clear starry night! I do not know if the bad sightings create a neg or pos on the anomaly, but it would be good to know in my opinion. Thanx for your time Doug.
124803. padruig at 07:53 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        I'm curious why these discussions fail to address the US Surface Climate Reference Network? An outgrowth of a study conducted in the late 1990's, the USCRN went online in 2003 to address some of the concern about site based bias in measurements. More information is available from NOAA. http://www.ncdc.noaa.gov/crn/
124804. Geo Guy at 07:47 AM on 29 January 2010
        The upcoming ice age has been postponed indefinitely
        I did read it and here is my response: - to attribute glacial periods to simply variations in the earth's orbit is somewhat simplistic given hat there are a lot of other parameters that affect whether glaciation occurs or not. Just having cooler temperatures is not enough - you also need precipitation in the form of snow such that accumulation exceeds melting. In addition to orbital variation, ocean currents and solar & cosmic radiation all factor into the equation.
124805. Thomas Hobbes at 07:46 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        In all of the explanations of the trend correlations described between the CRN 1 and 2 vs the CRN 3/4/5 sites, is there an implicit finding that there is a constant bias for a given site and that there is not a stochastic error term which is higher for the CRN 5 vs CRN 1 sites?
124806. Tom Dayton at 07:36 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        Alexandre, your reasoning is correct. That and related issues are discussed in the post and comments in the other thread--the one having John's original post, On the reliability of the US Surface Temperature Record.
124807. Leo G at 07:15 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        trrll @ 79 - Watts and Pielke Snr. are working on a paper. Should be interesting to see what they come up with with double the stations to work with
124808. John Cross at 07:02 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        John Congrats on your Guardian article. I think it is an excellent contribution. You also say "Anyway, it's weird excerpting my own writing" to which I reply, when referencing, always reference the best. John
124809. Leo G at 06:52 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        Mark J @ 15 - re: Watts?Pielke awaited paper, and so science goes, building, or tearing down, based upon past papers. Seems to work not bad eh?
124810. RSVP at 06:50 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        Thanks dhogaza for that clarification. Sounds good.
124811. MarkJ at 06:28 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        John - I'm sure you are aware that the counter from Watts is that the reason that he wants a fuller sample than that used by Menne before writing it up is because the earliest returns of photos of sites were naturally urban - close to the neighbourhoods of volunteers. I think it is arguable that he and Pielke Snr will get a strikingly different result when they get their turn to use their siting scores with temp data. I guess you didn't mention that because you think it is a weak argument by Watts? I don't think we will have too long to wait to find out.
124812. dhogaza at 06:15 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        RSVP ... "If a pristine mountain peak in the middle of the Pacific makes sense for monitoring CO2, why not apply similar rigor for weather stations? Instead of trying to salvage this data, maybe better to start from scratch. Dont we have 100 years or so to work on this problem? Much cheaper in the end too." Well, actually, a new temperature monitoring system, designed from the ground up to meet climatology needs, has not only been designed, but deployed. It's called the US Climate Reference Network. In fact, it's the CRN siting criteria that Anthony Watts is using to "prove" that certain stations in the Historical Climate Network are "bad" - using standards set in the last decade to categorize stations that are decades or a hundred years old. One of the results of the Menne 2010 paper is that the several years of USCRN data we have matches the temperatures derived from the historical stations extremely closely. Two separate sets of stations, one set explicitly designed to meet rigorous siting standards and provide optimal spatial coverage. The other a much larger set of stations placed originally to provide data for weather forecasting. And they match. And as years go on and they continue to match, it will only increase the confidence of the accuracy of data from the historical network of stations (though within science it's already sky-high). The historical data has been subject to dozens of tests, and has always passed with flying colors. The only test it hasn't passed is the "I took a photo but did no analysis" test, which is bogus. Not only do we not have 100 years to wait, there's no reason in the world to throw out existing, perfectly good, data - except for the politics of delayed action.
124813. Alexandre at 05:59 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        There's one thing in this subject that strikes me as obvious, but I haven't seen it so far (not that I've searched much): We're not talking about absolute temperatures, but instead they're temperature *anomalies*. If I had a termometer in an oven at 200ºC for the whole century, the anomaly would be zero. So having a termometer in a parking lot, while it yields of course a higher temperature, it does not produce increasingly higher temperatures over the years and decades. Am I oversimplifying it?
124814. Svatli at 05:37 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        Good article John. My view of why the denialists are gaining grounds is that they don't use solid arguments in their argumentation. They make it easy for people to follow their line of "logic". Pictures of "bad" sited temperature instruments seems to do the trick in many peoples mind. We know that the arguments of the denialists are simple, so thats why it's easy for general public to follow their kind of "logic". In the sametime the science is not as easy to follow and easy to misunderstand. But instead of trying to stay ground and defend the science, I thing the science should be made easier to follow. The only way, in my opinion, to manage that is to make an offensive, where you make it your goal to make climate science understandable for the general public. We still haven't achieved that goal, or maybe we still haven't set that goal... One reason for that, is that the climate science are complicated. But I thing that it's an achievable goal with the right means. I'm not an activist, but I think that by simplifying (in words) the science somehow we're half way there. This should not be the scientists job, and in many cases I don't think that it always lies in their skills to make a simple argument ;) They should be able to continue their work. But in some way I know that this is an achievable goal, with the right means. Regards, Svatli
124815. Albatross at 05:37 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        JPark, I have a question for you. Why are you having such a hard time understanding the findings of Mennes et al, despite the science being explained to you over and over? I do not sensing a sincere desire to learn on your part, but rather any opportunity to taunt and to obfuscate. Additionally, when posters here have provided very good arguments or explanations (which has been often), your retort has sometimes been to post yet another post from a political blog (WUWT). You seem to accept Anthony's pontification without question or critique. Why is that? I have a hypothesis, every time you close your eyes, you see Anthony's images of a station near a parking lot. If so, then you really do need to move beyond that. Someone called you a skeptic the other day, actually you are displaying traits of someone in denial about AGW, or those of a contrarian; rest assured, your actions show you to definitely not be a true skeptic. I'm hoping if you had a heart problem you would take the advice of the cardiologist and not that of say, your uncle Ben, who seems to be omniscient and very convincing at the dinner table with his anecdotes, but when his claims are checked out, most times they tend to be wrong. Watts by the way, is "uncle Ben".
124816. Albatross at 05:24 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Jpark, talking of being "behind the curve", have you found the values of the long term trends in global temperatures from the RSS, RATPAC, GISStemp, CRU and NCDC data yet? Do you know why I keep insisting that you look at the long term trends in those global temperature data sets?
124817. Berényi Péter at 03:44 AM on 29 January 2010
        Peer reviewed impacts of global warming
        You can defuse the population bomb through restriction of carbon based energy usage only by generating artificial famines. Is that what you want? I propose building & maintaining schools, training & paying teachers, educating girls worldwide. In several decades you'll have quite different problems with an overaged declining world population (as Europe and Japan already have). But it is another story.
124818. Berényi Péter at 03:22 AM on 29 January 2010
        Predicting future sea level rise
        Satellite sea level data are valuable in determining short time and/or regional changes, but they are absolutely infeasible to draw secular trends because of orbital drift. The problem is overcome by calibrating satellite measurements against tide gauges (just sixty four of them). The moral of the story is that sea level trends measured by satellites are not better than those measured by a few gauges at unspecified locations. http://sealevel.colorado.edu/ On the other hand, gauge data are of course measured relative to shore elevation which is also subject to regional change. Crustal segments have different and considerable vertical movement relative to both eachother and sea level. It is easy to see that the more gauges are used, the smaller the error gets. However, satellites are only calibrated against a restricted set. I could not find documentation about geographic distribution of tide gauges used in calibration at the UCB site. Reliable GPS calibration is not done yet, although it is said to be in the pipeline.
124819. NewYorkJ at 02:57 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        Good article. I'm glad the Guardian still publishes reasoned analysis. While I felt it was a fairly intuitive and complete discussion, I'm not sure it's going to satisfy the "photos don't lie" crowd who don't have the time, skill, or inclination to verify the study's conclusions for themselves. Their argument might be "how can we trust any 'analysis' when those photos clearly show urban or microsite warming influences...this just proves it's a scam." Addressing the photo argument more directly would be good - perhaps an intuitive explanation as to why such stations do not add an overall warming bias to the U.S. trend. The recent AMS USHCN version 2 study usefully addresses the Surface Stations argument. RSVP: "The continental US doesnt exactly seem like the best location on Earth for monitoring global warming." Tell that to the "global warming is a scam" crowd, who have been using relatively cooler U.S. temperatures over the last year or two to argue against global warming. Mr. Watts is a full participant in this line of spin. The U.S. surface record is unreliable, except during the times it shows cooler temperatures.
124820. Ubique at 01:52 AM on 29 January 2010
        The upcoming ice age has been postponed indefinitely
        Hi Tom. (#31) You may or may not be right. What Professor Plimmer says about climate does not stop him being an eminent geologist though! His academic qualifications and awards look pretty impressive.
        Response: Ian Plimer is a qualified scientist, which makes the statements he makes all the more baffling. Having read his book and listened to his interviews, I've heard him make the following statements:

        • 'Climate is always changing and climate scientists ignore this'. I wonder why he ignores the many studies that examine past climate change and calculate climate sensitivity - thus providing evidence for climate's sensitivity to CO2 forcing.
        • '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.
        • 'The amount of CO2 we emit is tiny compared to the amount that stays in the atmosphere'. Considering we emit 29 billion tonnes of CO2 and 15 billion tonnes stays in the atmosphere, I wonder how he works out 29 billion is tiny compared to 15 billion.

        Most perplexing for me is that he continues to repeat these falsehoods after his errors have been pointed out to him, with utmost confidence and contempt for, well, nearly every climate scientist in the world. I see him debate Barry Brook live this afternoon in Brisbane so maybe I'll gain more an insight then.
124821. Tom Dayton at 01:51 AM on 29 January 2010
        On the reliability of the U.S. Surface Temperature Record
        A good rebuttal to D'Aleo and Watts is provided by John Nielsen-Gammon (Prof. of Meteorology at Texas A&M U., and Texas State Climatologist). But that portion of that blog post doesn't start until about one third of the way down; look for the paragraph that starts "Meanwhile," or Find "Watts." Includes a numerical example.
124822. Tom Dayton at 01:32 AM on 29 January 2010
        The upcoming ice age has been postponed indefinitely
        Ubique, Ian Plimer is a poor choice to hold up as an "eminent geologist." His opinions on climate are complete nonsense--not just wrong, but really far, far off. Just one of many places you can find detailed rebuttals to his claims is Deltoid.
124823. inthewoods at 01:05 AM on 29 January 2010
        Guest post in Guardian on microsite influences
        John - thanks for the response - the NOAA article was the reference I was looking for. I'm just curious - WUWT seems to have devolved into just a load of total nonsense that is obviously nonsense. ClimateAudit.org seems to still have an air of "trying to be somewhat scientific" (when you weed through all the FOIA and BS email analysis) - I'd love to see a more through take-down of his analytical posts....anything in the works there or just too much work for too little benefit?
124824. Ubique at 23:37 PM on 28 January 2010
        The upcoming ice age has been postponed indefinitely
        NewYorkJ(#28 Thank you for that. I am neither a convinced sceptic nor alarmist - just an average guy trying to make sense of all this stuff as I have a professional interest in the application of this science. But it seems that one cannot be neutral in this debate - so at the moment I must err on the sceptic side as I am still asking questions and trying to keep an OPEN mind rather than trying to BROADEN it as John suggested rather tartly in his response to my post. I was thinking of Professor Ian Plimmer when I said eminent geologists, not the author of Geocraft who I would not know from Adam - apologies if I implied the latter. As a result of "Climategate" I am not sure whose information to trust - along with a great many other people on the edge of this issue I would imagine!
124825. Jesús Rosino at 23:33 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        Congratulations, John. I very much liked your article, sounds very natural and it's easy to follow, well fitted to the general audience. It highlights the recurrent skeptical strateggy of arguing with insinuations instead of with actual analysis. It's much quicker and they can produce many more (flawed) arguments, while real scientists spend their time in the (much more time-demanding) real analysis (to be published once the flawed conclussion has already spread out). This is the standard style of Climate Audit, for example. As Winston Churchill said, ‘A lie gets halfway around the world before the truth has a chance to get its pants on’. People must learn to discern what the real scope and implications of a discovery is. Eg. "I discovered a handful of trees crowded together in northern Siberia with a divergence problem". Does it prove that all reconstructions of global temperature over the past 1,000 years are wrong? You don't need a leading scientist doing the hard work to know that insinuations don't prove anyting. Exactly the same with poorly-sited weather stations and Anthony Watts' gratuitous insinuations.
124826. Marcus at 22:57 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        Oh get real RSVP, do you honestly think that our researchers are so thick that they haven't considered everything you've mentioned, & account for it in their calculations? What is of concern is the warming which has occurred in the last 60 years, which has been measured by suitably reliable measuring stations. Seriously, I really don't know why you're so keen to make excuses for the "head-in-the-sand" approach taken by the Denialist Cult.
124827. Marcus at 22:54 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        RSVP, if its winter where you are, then why are you surprised that the temperature is -7 degrees? Here in Australia most of the country has had temperatures at least +2 to +3 degrees C above average for the last 3 months (Adelaide temperatures for November were more than 5 degrees above average), & AMSU-A shows global January 2009 temperatures to be more than +0.2 degrees above those of 2009-your little corner of the world clearly doesn't represent the world entire. Also, I don't believe we have 100 years to fix the problem. Satellite & surface temperatures are in agreement-+0.16 degrees per decade since 1979. As we don't know for certain just how had the impacts of future rises are going to be, I think it would be irresponsible to wait 100 years to "double check". If we don't take serious action within the next 20-30 years, I believe it will be too late to avert a truly catastrophic rise in temperatures. The fact is that, had we listened to the scientists 20 years ago, instead of letting the fossil fuel industry have its way, CO2 mitigation would have been a *hell* of a lot cheaper!
124828. RSVP at 22:38 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        yocta This is taken from the site "Temporal Representativeness In addition to difficulties with the correct exposure of instruments, thought has to be given to changes in the long-term exposure of the site. Buildings in close proximity to the instrument enclosure will result in the area of representativeness being reduced. For example, when the instrument enclosure at Sydney was installed in 1788, the instruments were representative of a relatively wide area around Sydney. With subsequent construction of high-rise buildings and freeways, climatic and meteorological conditions only 50m from the site are now significantly different to those at the site. It is important that the station be inspected regularly and any changes in the siting are properly documented." 1788? Aside from the site, what about technology? Was there even a universal standard set of measurements in 1788? I must be going nuts, or is it the CO2?
124829. Riccardo at 21:51 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        HumanityRules, the use of the raw readings of a station to construct a long time serie is a myth, too many things change with time. Indeed, making a reliable time serie is the most difficult part and a lot of effort has been put to make the raw reading reliable over time. There is no way to extract usefull climatic information from raw data. You can get some general idea of the process from the NCDC itself; no mistery, no hiding.
124830. HumanityRules at 21:45 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Update 28/1/10 John could you explain homogenization and interpolation and their relation to raw and adjusted data. because it seems what Watts is complaining about is the interpolation process which he call homogenization. I think!
        Response: Interpolation and homogenization are two different things. The strict definition of interpolation is filling in the gaps between data (as opposed to extrapolation which is extending beyond your data). In the case of surface temperature, it's been observed that there is strong correlation of temperature anomaly between adjacent regions so interpolation into regions where no measurements have been taken can be done with some degree of confidence.
        
        This is also somewhat related to geospatial averaging - Tom Dayton posted a good explanation of that here... 
        
        Homogenization is the process of adjusting the data to remove spurious biases. For example, moving a weather station to a different location, changing the instrument that measures temperature or changing the time of day that the measurements are taken can all impose warming or cooling biases on temperature readings.
124831. yocta at 21:21 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        The Australian Bureau of Meteorology has a nice little page of the requirements for Australia's Automatic Weather Stations , with details including where they are and site requirements. The site lists exactly the things a trained metrologist needs to consider when seeting up any decent temperature monitoring system: Resolution, Repeatability, Response time, Drift, Hysteresis, and Linearity. It is interesting that in all of this that Watts and the WUWT members seem to forget that America is actually not the world. Australia is of pretty comparable surface area wise to America and if the stations here report a similar warming trend... I wait with keen eyes for Watts full analysis!
124832. RSVP at 20:15 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        It is -7C, 9:10 in the morning (daylight "savings"), not a cloud in any direction, the sun shining bright and beautifully. I am suppose believe it is warmer than it should be. "Please Sun, do your thing." The thought of hundreds of bogus weather stations occupies me after seeing this theme now repeated. 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. And I am not talking about termocouple specs or a thermometer's rating. I am talking about the system as a whole (its total accuracy), and how it is set up. (The graphs of figure 2 in the original article were plotting values to within a tenth of a degree, which implies an accuracy of +-.05. Spectacular, but real?) If a pristine mountain peak in the middle of the Pacific makes sense for monitoring CO2, why not apply similar rigor for weather stations? Instead of trying to salvage this data, maybe better to start from scratch. Dont we have 100 years or so to work on this problem? Much cheaper in the end too. Aside from issues of accuracy, another important system parameter is repeatability. Repeatibility that can be guaranteed over many years. If you were to simply take the sum of measurements over time from a set of reliable and repeatable instruments, (even if every sensor was buried in a 1 meter cube of cement), this global checksum would tell you something about global warming, because it is the relative change that matters, not the absolute temperature reading. My last remark. The continental US doesnt exactly seem like the best location on Earth for monitoring global warming.
124833. HumanityRules at 20:11 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        doug_bostrom at 17:07 PM on 27 January, 2010 doug, while being a scientist, it's not really the science of climate change I'm interested in, it's the politics. So no I haven't been clinging to any ideas for years. I keep coming back to John's website because I find it challenging and I try to critically appraise it for that reason. The reason I asked those question. Maybe summed up as is instrument change the only real factor in microsite issues of stations because come the adjustment process there appears to be multiple points at which data is adjusted. The following image is a site that got alot of coverage on skeptic sites, it's Darwin Airport, Australia. http://www.estatevaults.com/bol/_graph_cru-darwin7.jpg While there is a big jump in 1940 (maybe location change) there are also many small, positive changes from 1940-1980 giving an apparent trend. What is the justification for these if the Menne 2010 paper has ruled out almost all influence from microsite changes?
124834. HumanityRules at 20:02 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        Congratulations, very prestigious.
124835. inthewoods at 19:47 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        John - I remember reading about a construction of the temperature record using only the sites that WUWT considered "good" - and the conclusion was that the record lined up perfectly with other records. Do you happen to remember the article or have a link?
        Response: I'm just going from memory here so anyone chime in if I get the details slightly wrong. Early in the history of the surfacestations.org project, one of the users John V took the existing ratings and compared the temperature trend from the best weather stations (rating 1 and 2) to the GISS temperature record. The expectation was that the GISS temp would show a warmer trend as it included all those poorly sited stations besetted with microsite influences. Instead, John V found the good weather stations showed a near identical trend:
        
        
        
        While this result was initially met with dismay, Watts rallied and criticised the result, saying it was made with only a small percentage of stations being rated. I believe some time after this, Anthony Watts made the data on station ratings unavailable to prevent any other data analyses comparing good and bad weather stations - but I'm not sure of the timing of this.
        
        The next analysis was by NOAA who also published an analysis comparing only the good stations to the total record (NOAA 2009):
        
        
        
        Again, the trends are near identical (you expect some discrepancy as both records cover slightly different regions). Watts criticised this result as a result of homogenisation (data adjustment) of both the good data and the full dataset. That's why Menne 2010 is interesting in that it uses unadjusted data - this is where the cooling bias is revealed.
        
124836. jpark at 19:01 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        ... I am behind the curve as ever ;-)
124837. jpark at 18:57 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Maybe not yet... quote: I realize all of this isn’t a complete rebuttal to Menne et al 2010, but I want to save that option for more detail for the possibility of placing a comment in The Journal of Geophysical Research. When our paper with the most current data is completed (and hopefully accepted in a journal), we’ll let peer reviewed science do the comparison on data and methods, and we’ll see how it works out. Could I be wrong? I’m prepared for that possibility. But everything I’ve seen so far tells me I’m on the right track.
124838. jpark at 18:52 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        Helpful? http://wattsupwiththat.com/2010/01/27/rumours-of-my-death-have-been-greatly-exaggerated/
        Response: Already updated the article above responding to Watt's latest post, which is a little disappointing but understandable if he's saving his best material for peer review.
124839. Albatross at 16:00 PM on 28 January 2010
        Guest post in Guardian on microsite influences
        John, excellent job. Thanks for agreeing to do the article. Education on the science behind climate change is key to helping the general public come to terms with what is happening with AGW and what is expected to happen as AGW ramps up in coming decades. I hope that they ask you back to speak to other issues, and that you accept. I've being trying to encourage the editor of one of our provincial newspapers to have a regular column for the purpose of educating the public on climate science and meteorology but to no avail.
124840. Tom Dayton at 15:21 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron2000 asked "I think this is a lot of geospatial averaging of the monthly anomalies and the mean anomaly which goes on prior to actually making our comparisons of temperature anomalies, right? Why was this done? What is the effect of doing it? Would the results be different if you didn't? "Gridding," as geospatial averaging is called, is not just useful. It is essential because we are trying to measure the temperature of the Earth, not of the thermometers. The thermometer manufacturer might be interested in the thermometers themselves in order to assess, oh, say manufacturing quality, so the manufacturer might not care where the thermometers are located. But we use thermometers only as a means to measure the temperature of the Earth's surface. Measuring the temperature of the Earth's surface requires taking a representative sample of the Earth's surface. We do that by dividing the surface into equal sized grid squares and finding a single temperature for each grid square. Then we average all those. The result is an average temperature that equally weights every grid square. In contrast, if we simply averaged all the thermometers regardless of their location, we would have an unrepresentative sample of the Earth's surface. Imagine that on the entire Earth we had only 1,001 thermometers--1,000 in Death Valley but only one at the North Pole. If we simply averaged all 1,001 thermometers' temperatures, the resulting single temperature would be a gross overestimate of the Earth's temperature. It would be nice if our thermometers happened to be distributed completely evenly, because then we could take the shortcut of simply averaging all the thermometers. But in reality, thermometers are very nonuniformly distributed. So we must gather a representative sample of the Earth's surface by computing only a single temperature for each grid square. If one particular grid square happens to have 10 thermometers and another grid square happens to have only 1, then that first grid square's temperature (the average of those 10) probably will be a better estimate of that square's "true" temperature. But its estimate will not be biased in any direction, compared to the square having only a single thermometer.
124841. Doug Bostrom at 15:09 PM on 28 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Philip64 at 22:22 PM on 27 January, 2010 "Where did this IPCC response appear? I would hope in The Sunday Times itself, but given the way that paper is sliding on this issue, I wouldn't be surprised if that was not the case. " Only on the IPCC site itself, as far as I know, and then picked up by ClimateProgress, possibly other sites. It's not stinky enough to be picked up by newspapers.
124842. Doug Bostrom at 15:05 PM on 28 January 2010
        On the reliability of the U.S. Surface Temperature Record
        sbarron2000 at 05:51 AM on 28 January, 2010 "But I'll be interested to see if anyone challenges these findings. " Reputations partially depend on it. I'm sure somebody's scorching a spreadsheet even now, trying to salvage the original hypothesis. It'll be a challenge, though. The basic mechanism at play is a lead pipe cinch. Want to see an actual skeptic? Look no farther than Mennes.
124843. Doug Bostrom at 14:56 PM on 28 January 2010
        Peer reviewed impacts of global warming
        Berényi Péter at 08:49 AM on 28 January, 2010 "You guys sometimes remind me to jinxes at the end of the nineteenth century preaching doom because of ever increasing traffic and transportation. According to them all the great cities of the world should have been buried under heaps of horse dung long ago." Bah. We're not doomed, we're like roaches. But we don't have to live like insects, either. There's a big difference in population, some 5 billion or a 430% increase since 1900. Expecting to draw a useful conclusion from 110 year old population data is a mistake.
124844. Charlie A at 12:52 PM on 28 January 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        I have found a peer reviewed paper from Geophysical Research Letters that supports the AR4 findings! Indeed, they are a bit more aggressive in their prediction in that they expect the total area of glaciers in all of the Tibetan Plateau to be reduced from 500,000 sq km down to 100,000 sq km by 2030 --- a full 5 years earlier than IPCC. So the IPCC now has a peer reviewed article to use as a reference if IPCC wants to put into ar5 a statement similar to the one in AR4. There are just 2 problems ---- Cruz et al (2007) is actually chap 10, WGII, AR4.; and the area given in the paper for total glacial area in the Tibetan Plateau is laughably incorrect. (See for example the WGMS - world glacier monitoring system -- numbers. See Mass loss on Himalayan glacier endangers water resources, http://bprc.osu.edu/Icecore/Kehrwald%20et%20al%202008.pdf Key quotes from the article: "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], thereby threatening regional rivers and water resources." "Himalayan glaciers have been retreating more rapidly than glaciers elsewhere in the world [Cruz et al.,2007]." I have not been able to determine how the AR4 500k sq km of Himalayan glaciers became all of Tibetan Plateau in the peer reviewed article. Nor have I been able to determine how the date for reaching 100k sq km was changed to 2030 from 2035. Does anybody have any idea how these changes came about?
124845. canbanjo at 10:36 AM on 28 January 2010
        Peer reviewed impacts of global warming
        If 2 of the richest countries that have huge areas of desert with the best solar pv potential (USA / Australia) can't even build big pv farms then what hope does africa have?
124846. Marcus at 09:47 AM on 28 January 2010
        The upcoming ice age has been postponed indefinitely
        @17. The only reason temperatures were so much warmer several million years ago is because CO2 concentrations in the atmosphere were several times higher than they are today. The entire Quaternary period has been dominated by an average global temperature of 15 degrees C, which seems to be the ideal conditions for human agriculture & civilization. The only way in which we'll see a return of "hot-house Earth" is if (a) solar irradiance increases substantially or (b) we return CO2 concentrations in the atmosphere to levels unseen since the Cretaceous Era. Such a scenario would undoubtedly bring an end to human civilization.
124847. NewYorkJ at 09:32 AM on 28 January 2010
        The upcoming ice age has been postponed indefinitely
        Ubique (#24), I'm not sure Monte Heib (author of geocraft.com) is an "eminent" geologist. From what I gather, he's intimately tied to the WV coal mining industry. No surprise he wants to push the idea that burning coal is harmless. Scanning his site, I find his writing style to be a bit weird: "Human's did not cause the greenhouse effect, but critics maintain human additions to atmospheric greenhouse gases may cause global temperatures to rise too much." Who are these "critics"? Why not just say "scientists"? Perhaps he sees them more as "critics", since their research has implications for his industry. "Generally understood, but rarely publicized is the fact that 95% of the greenhouse effect is due solely to natural water vapor." Common skeptic fallacy: http://www.skepticalscience.com/water-vapor-greenhouse-gas.htm "Overall, U.S. temperatures show no significant warming trend over the last 100 years (1). This has been well - established but not well - publicized." Interestingly, he then follows with a chart of U.S. mean temperature that shows a strong linear trend through the period of record.
124848. Tony O at 09:27 AM on 28 January 2010
        The upcoming ice age has been postponed indefinitely
        Thanks John, A really interesting topic. Very much related is the question of short term climate sensitivity to long term climate sensitivity. Once the slow feed backs are added it would appear the climate can be extremely sensitive to tiny changes in forcing. But it does not follow that it will continue to be as extremely sensitive once the slow feed-backs have run their course. Or have I misread Ruddiman? (always possible)
124849. LucAstro at 09:20 AM on 28 January 2010
        The upcoming ice age has been postponed indefinitely
        Great post. A minor flaw I think is to plot the solar TSI curve and then discuss forcing. In the case of solar forcing, one divides the TSI values by four, right? From your first plot, one would infer that the difference between the Maunder Minimum levels and current solar activity is of order 1W/m2, which, if divided by four, would be quite close to the values of solar forcing that you quote, that is: ...between 0.17 W/m2 (Wang 2005) to 0.23 W/m2 (Krivova 2007).
        Response: "In the case of solar forcing, one divides the TSI values by four, right?"
        
        Close. Firstly, yes, to convert the change in Total Solar Irradiance to radiative forcing, you need to divide by four (the difference between the surface area of a disc which is how Earth absorbs sunlight and the surface area of a sphere). But you also need to remove another 30% of this value to take into account the albedo of the Earth.
        
        So Solar Forcing = ΔTSI * 0.7 * 0.25 = ΔTSI * 0.175
        
        Wang 2005 found the change in TSI since the Maunder Minimum was ~ 1 Wm^-2. This translates to a radiative forcing of 0.175 Wm^-2. Similarly, Krivova 2007 finds the increase in the solar total irradiance since the Maunder minimum is 1.3 Wm^-2 which translates to a radiative forcing of 0.2275 Wm^-2.
124850. Jacob Bock Axelsen at 09:15 AM on 28 January 2010
        The chaos of confusing the concepts
        I think some illustrative movies are called for. Experiments. 1. Non-chaotic convection (from above): http://www.youtube.com/watch?v=UhImCA5DsQ0&NR=1 2. Mildly chaotic: http://www.youtube.com/watch?v=lbRzeXPuJIo&feature=related 3. Jupiter's weather is both chaotic (f.ex. the red spot) and turbulent (eddies of all sizes): http://www.youtube.com/watch?v=yjU_CJWzAd4&feature=related ----------- Simulations. 1. Non-chaotic Rayleigh-Bènard convection: http://www.youtube.com/watch?v=yRjSXBLvIFo 2. Chaotic: http://www.youtube.com/watch?v=1yBz4U7Xbmc&feature=related 3. Strong chaos/soft turbulence (but still nice): http://www.youtube.com/watch?v=fGvXK_qb5fY Enjoy!

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