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Comments 124551 to 124600:

124551. carrot eater at 02:24 AM on 2 February 2010
        On the reliability of the U.S. Surface Temperature Record
        jpark: You can see the result of the homogenisation for Reno yourself, in the paper I cited. A huge warming trend is significantly reduced. Where some sceptics get confused is that they think UHI is the only thing you'd ever need to adjust for, and then they get angry when they see any upwards adjustments. However, other things can require either upwards or downwards adjustments, and in the US, changes in the time of observation stand out as a requiring upwards adjustments. One thing to not forget is the US CRN network, which is entirely sited to avoid any of these problems. It's newish, but it's been up for a few years now. After adjustments, Menne (2010) showed that even the 'poor' stations matched the US CRN. That would tell you that they're doing something right.
124552. jpark at 02:02 AM on 2 February 2010
        On the reliability of the U.S. Surface Temperature Record
        Carrot eater - v helpful. So the temperatures are adjusted down to counteract the UHI, yes?
124553. jpark at 01:59 AM on 2 February 2010
        On the reliability of the U.S. Surface Temperature Record
        Thanks Ricardo - lets see if they do the analysis then. Pity Menne only used 40% of the available data tho. Bit like only using some bristlecones, like a D'Arrigo cherry picked pie. Pielke says "We will discuss the science of the analysis in a subsequent post and a paper which is being prepared for submission." so it looks like it is happening...
124554. carrot eater at 01:55 AM on 2 February 2010
        On the reliability of the U.S. Surface Temperature Record
        jpark, this is tosh. Anybody knows there are individual stations out there that show urban heating. You don't need Watts for that; you can see it from the people who actually do published work. The question is whether those effects are contaminating the overall surface record, and by any actual analysis, they appear to not do so. It's funny that Watts chose to highlight Reno NV, without telling you that the USHCN's method removes the urban heating for that station. See Figure 8 in Menne, Williams and Vose (2009) BAMS, 90: 993-1007. Link was given above somewhere.
124555. Riccardo at 01:12 AM on 2 February 2010
        On the reliability of the U.S. Surface Temperature Record
        come on jpark, you know very well that when the data are homogenized ("adjusted") people (sceptics) screams out loud. This is the very reason why they show raw data only. We all know that UHI exists and indeed, before being considered for the average of their respective grid point data are corrected for UHI effect, station movement, instrument change, etc. I've never (NEVER) seen Watt do the full analysis. Given that behind Watt there is Roger Pielke Sr., they sure have the skill to do it. If they don't, the reason is clear. That post is just a confirmation that what they say is irrelevant.
124556. Alexandre at 01:08 AM on 2 February 2010
        It's cosmic rays
        Here's the graph I mentioned above about the Laschamp event: http://ossfoundation.us/projects/environment/global-warming/myths/images/galactic-cosmic-rays/LaschampAnomaly.jpg/view I presume it comes from this paper: Muscheler et al. 2005 "Geomagnetic field intensity during the last 60,000 years based on 10Be and 36Cl from the Summit ice cores and 14C" [Muscheler 2005] The graph looks pretty strinking to me. John, do you think it would be worth adding this to a future update on this argument?
        Moderator Response: [RH] Hot linked Musch paper.
124557. Doug Cannon at 00:31 AM on 2 February 2010
        It's cooling
        Note that NODC has updated the ocean heat content figures through 2009. You may want to update your graph.
124558. Berényi Péter at 23:52 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        I wonder why this drop was not reported earlier. After all it occured almost a decade ago.
124559. Gianfranco at 23:46 PM on 1 February 2010
        Understanding Trenberth's travesty
        Thank you very much for the excellent explanation. One point still puzzles me, though, perhaps because I'm Italian: the word 'travesty'. According to my good old Oxford Dictionary it means 'a description that intentionally misrepresents the original e.g. burlesque poem etc.' etymology being the Italian verb travestire = disguise. It somehow conveys the impression that the whole thing is a farce, a dress up, an attempt to deceive. I understand in private informal correspondence one doesn't care much about wording, but, why didn't he use pity or shame or bad luck?
124560. jpark at 23:38 PM on 1 February 2010
        On the reliability of the U.S. Surface Temperature Record
        Hi is this on topic? http://wattsupwiththat.com/2010/01/31/uhi-is-alive-and-well/ If you live in a city as I do then you know how much warmer it is than the surrounding countryside. To be told that sitings of temp stations dont reflect this is counter intuitive and makes me very suspicious of the way Menne got his results - a bit like Mann's famous, now broken, hockey stick.
124561. J Bowers at 22:20 PM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        RSVP wrote: "In terms of probability, it would seem to make the chances of life on Earth diminish if this were the case, and yet here we are having (supposedly) evolved on this planet for millions and millions of years." But our mammalian ancestors were small rodent-like animals, and were able to burrow into the ground to avoid the effects of brief extreme temperature during the K/T Event extinction. Insects and marine plants would have still been available to eat immediately afterwards. The earliest known tool-using humans, homo habilis, never experienced anything they couldn't adapt to nor migrate from, and were far fewer in population number so resources were less contested. The Late Pleistocene Extinctions affected large herbivores, and each Late Pleistocene event also happened on a different land mass. The causes of the Late Pleistocene Extinctions are still unknown, but the three main candidates that I know of are: Human over-hunting or hunting a keystone species to extinction; Climate change causing large changes in the ecosystem; Hyperdiseases carried by migrating humans. Or, a combination of all three. Even during glacial ice ages, the southern hemisphere was still mostly tropical or subtropical.
124562. RSVP at 21:36 PM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        GFW Up until now, I understood that the Earth could sustain life as we know it because it had an atmosphere, a lot of water, and just happened to be the right distance from a rather average (not too big) non-binary star. (Not to mention other "invisible shields" that magically serve protection as well etc.) All that is pretty awesome in itself, however, there would be a point at which the requirements for sustaining life must loosen, and that the particular amount of carbon you are talking about is not one of these requirements. In terms of probability, it would seem to make the chances of life on Earth diminish if this were the case, and yet here we are having (supposedly) evolved on this planet for millions and millions of years. Something doesnt seem to add up here, and as per Occam's razor, one should look for a simple explanation. It seems like these theories depend almost too much on carbon cycles and make them seem circular in themselves. Anything is possible and maybe we dont realize how delicate the balance really is, however, being an optimist, couldnt the triple point of water along with the vast amounts of it on the surface of the Earth have something to do with this notable clipping?
124563. GFW at 19:39 PM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        Agreed that the behavior for several glacial/interglacial periods has been bounded and fairly periodic, but that's not bi-stable. True bi-stability would be suggested if (a) the system spent more time at the two extrema and (b) the transitions were less regular. You'd also need to propose a negative mechanism (or two) to provide the stability at the two extrema. I'd suggest that the bounds of the observed range are mostly determined by the amount of carbon available, and the period of the dominant Milankovitch cycle. Specifically, temperature falls while the Milankovitch forcing is negative, with the rate of fall limited by the carbon cycle's ability to scrub and sequester carbon (in the ocean, in peat bogs that then get glaciated over, etc.). When the Milankovitch forcing turns positive, slow warming starts, then accelerates as the initial warming causes the ocean to outgas CO2 and the glaciers to start exposing the decomposed peat. One good question would be why the amount of carbon available to the cycle has been roughly constant for several hundred thousand years. I'm guessing that that's not long enough for tectonic processes to bury seafloor carbon, nor reconfigure the topography of the oceans, so each warming releases the same carbon each time. If there were significant uplift under methane hydrate deposits, the amount of carbon available to the cycle would go up for a while, until new deep stores of the hydrates could form. If enough time passed to form new fossil fuel deposits, that would reduce the amount of carbon available to the cycle. If we burn large quantities of fossil fuels ... well, that's the topic of the 3rd figure in the page you pointed to.
124564. Doug Bostrom at 18:58 PM on 1 February 2010
        Understanding Trenberth's travesty
        This article seems like a great candidate for a revisit after Solomon's article on vanished vapor. A significant part of Trenberth's gap is seemingly plugged, if Solomon's results stand it'll be a great improvement in our understanding of variability.
124565. Ari Jokimäki at 18:14 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        John Cook wrote: "The radiative forcing changes (Figure 3 above) indicate that the overall effect from stratospheric water vapor is that of warming. The cooling period consists of a stepwise drop around 2000 followed by a resumption of the warming effect. This seems to speak against the possibility of a negative feedback." Looking at the overall effect in your Figure 3, it is quite clear that if there is a feedback involved, it is a positive one, not negative.
        Response: I thought so too but as the authors didn't explicitly say that and I was presenting the results of the paper, I didn't say so. That's the opinion of Gavin Schmidt at Real Climate also.
124566. RSVP at 16:37 PM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        GFW If you look at the graph (figure 2) in... http://www.skepticalscience.com/upcoming-ice-age-postponed-indefinitely.html you will notice that there are basically two states, suggesting "bi-stability". The high curiously peaks around the same high temperature, and the low generally hovers around the same low temperature. The system appears sensitive (as seen by the many interrum fluctuations), but this sensitity is only observed within a fixed range of max min temperatures. In other words, it "wants" to be in one state or the other. Why does it always return to the exact same max, for instance?
124567. yocta at 16:20 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Any idea where the 10% water vapour went? What I mean is, besides change in global temperatures and radiative forcing is there any say...increase in rainfall on average in some areas, or shrinking clouds over the past decade that could be linked to this? Or is 10% of atmospheric concentration of water (0.40%) to small to notice anywhere else?
124568. Albatross at 16:19 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        John et al, Regarding "....the effect from stratospheric water vapor contributes a fraction of the temperature change imposed from man-made greenhouse gases. Stratospheric water vapor has a significant effect but it's hardly the dominant driver of climate being portrayed by some blogs." These sentences seem to contradict one another. In the first you state that SWV "contributes a fraction of the temperature change imposed by" anthro GHGs. With this I agree, going by the scale provided, the forcing from SWV in 2000 was ~0.2 W m-2, with the drop in forcing from SWV in 2001 a paltry 0.1 W m-2. [To put these numbers in perspective the radiative forcing for CO2 in 2008 was ~1.74 Wm-2 and that of CH4 0.50 W m-2 (thanks for the link padruig @7). So the forcing from SWV is less than 9% of the forcing from CO2 and CH4 combined.] But, in the second sentence you state that "SWV" has a "significant effect". Perhaps once should say that "the while forcing of SWV is not insignificant (i.e, is not too small to ignore), it is hardly...." There is probably a more eloquent way of stating this, but it is late here. In my humble opinion, while this work of Solomon et al. is valuable and interesting, it does not in any way undermine the theory of AGW. A scale analysis shows that the forcing from SWV is currently <9% of that from CO2 and CH4. Not only that but the long term trend in the forcing of SWV shown in Fig 3. above is positive (the slope of the line after 2001 is almost the same as that prior to 2001). The decrease in SWV around 2001 is interesting, and more work needs to be undertaken to determine the cause of the decrease-- it is not b/c of instrumentation issues because is was detected by independent monitoring platforms. Anyhow, this is not the silver bullet that those in denial about AGW are hoping for. They can try and spin it that way, but doing so is does not going to reverse the slope of the line in Figure 3 above, or the reality that the forcing from SWV is already overwhelmed by that of anthro GHGs. In fact, in 2008 the radiative forcing of SWV was on par with that of N20 (NOAA/ESLR).
        Response: On the one hand, "is significant" or "is not insignificant" seems a little po-tay-to, po-tah-to, but yes, "is not insignificant" probably does capture the sense of what I was trying to communicate so I've updated the wording :-)
124569. chris1204 at 15:58 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Marcus, if you look at http://www.esrl.noaa.gov/gmd/aggi/ you will read: ‘The growth rate of methane declined from 1983 until 1999, consistent with an approach to steady state. Superimposed on this decline is significant interannual variability in growth rate [Dlugokencky et al., 1998, 2003]. The approach to steady state may have been accelerated by the economic collapse of the former Soviet Union and decreased emissions from the fossil fuel sector. From 1999 to 2006, the CH4 burden was about constant, but in 2007 and 2008, globally averaged CH4 began to increase again.’ At the same time, http://www.nature.com/climate/2009/0904/full/climate.2009.24.html whilst raising the alarm about methane emanating from permafrost in fact also states: ‘Ed Dlugokencky, an atmospheric chemist with the US National Oceanographic and Atmospheric Administration in Boulder, Colorado, who oversees their atmospheric-methane measurement program, says indications are that global methane levels remained high in 2008, but he expects to see a return to previous levels over the long term. "If I had to make a prediction about what's going to happen in the future based on the last three decades of observations, I would say that there's a reasonable chance methane will continue to stay flat or even decrease before we see the effects of a warming climate on methane sources," says Dlugokencky. White agrees and says it's too early to tell whether this is a blip on the radar or a true signal that change is afoot. "I think we're going to need to see two to three years or more with increased methane in order to make a strong statement that we're beginning to see permafrost degradation resulting in methane increase," says White.’ So our moderator’s comment: ‘I think we all need to take a deep breath and calm down a little. Not because this isn't an important issue but because this is such an important issue’ is very apposite. At the same time, those at the cutting edge of ‘the science’ seem to be hedging their bets on the issue acknowledging the complexities involved. Returning to the original subject, stratospheric water vapour, I note that ‘The paper doesn't draw any conclusions regarding cause, stating that it's not clear whether the water vapor changes are caused by a climate feedback or decadal variability....’ Accepting for the time being the proposition that ‘The radiative forcing changes (Figure 3 above) indicate that the overall effect from stratospheric water vapor is that of warming,’ I’d be interested in any comments relating to increased atmospheric water vapour and precipitation. This would be very pertinent in relation to other issues raised in these forums such as glacier growth and the impact on regions dependent on such sources for water supply.
124570. Marcus at 14:06 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Sorry to be picky, padruig, but I think you mean 1800ppbv. Either way, though, that is much, much higher than pre-industrial levels of barely 700ppbv. Indeed, wheras CO2 levels have "only" increased by 38% above 1750 levels, Methane has increased by almost 70% above 1750 levels!
124571. padruig at 13:35 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Using the running mean as a guage, measurements of methane show it leveled off from 1999 to 2002, rose again peaking in 2003 followed by a drop returning to roughly 2002 levels. This was followed by a shallow bump in 2006. A point of concern is that in 2007 the rise observed prior to 1999 began to continue. Currently NOAA is reporting that we've exceeded 1800ppmv for methane. You can read NOAA's AGGI report ( updated Sept 09) here http://www.esrl.noaa.gov/gmd/aggi/ You can also read about terrestrial stores of methane here - http://www.nature.com/climate/2009/0904/full/climate.2009.24.html If I am not mistaken Nature Reports Climate Change is free to download.
124572. Marcus at 13:30 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Yet from my reading of it, the rise in stratospheric water vapor, irrespective of its radiative forcing potential, seems to have its likely origins in the oxidation of anthropogenic methane. If this is correct, then in my opinion this paper actually *supports* anthropogenic global warming even more.
124573. chris1204 at 13:08 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        The abstract from Solomon 2010 states: 'More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% compared to estimates neglecting this change.' 30% is pretty substantial by any standard bearing in mind that we have systems that are very sensitive to positive and negative feedbacks. It's all the more interesting considering that 1998 seems to have been an exceptionally warm year (whether because of ENSO or other causes) with evidence of subsequent relative cooling. Marcus, the reported levelling off of methane levels is surely very worthy of note given its reported significance as a greenhouse gas. We are dealing with complex systems which we do not undertsand well. With respect, the gratuitous references to 'contrarians' and 'denialists' that often appear on this site have a quasi-religious flavour which are out of keeping with the spirit of genuine scientific enquiry.
        Response: I am making more effort to moderate the labelling and ad hominem comments in order to maintain scientifically constructive dialogue. Consequently, I've been deleting a great number of comments lately (from both sides of the debate). I think we all need to take a deep breath and calm down a little. Not because this isn't an important issue but because this is such an important issue.
124574. Marcus at 13:06 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Thing is, though, that it only *started* to level off-it was still rising right up until 2000-2001, though at a slower rate from 1992-2000 than in 1980-1992. Given that methane has a half-life of 7 years, then I think it's perfectly in line with observed drop in stratospheric water. Lets not also forget that the other by-product of methane oxidation is carbon dioxide-another greenhouse gas.
124575. GFW at 13:00 PM on 1 February 2010
        The sun is getting hotter
        The section on independent tests is really good showing multiple measurements and proxies for TSI, with solid agreement. Are you aware of any measurements over the 1990-92 period using radio wavelengths (eg 10.7cm) that would also serve as a calibration? BTW, you wrote Challenge instead of Challenger.
        Response: Fixed the Challenger typo, thanks for the tip.
124576. GFW at 12:43 PM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        @61 shawnhet Yes, one can attempt to reconcile Plimer (non-anthtro forces have changed climate by large amounts in the past) with Monckton (sensitivity to forcing is low) by suggesting that past climate change has required strong forcing. But, the obvious question is then "what strong forcings"? Nothing in physics or paleontology would suggest that our sun has varied its output by enough to force the glacial periods. The most clever idea I heard for such a forcing was cosmic rays causing significant albedo changes by stimulating cloud formation. But recent measurements almost certainly rule that out. The thing is, the glacial/interglacial periods do line up rather well with forcing from Milankovitch cycles - and those forcing are weak. So there'd have to be a strong forcing we can't detect (nor apparently imagine) that just happened to operate at the same times as Milankovitch cycles. It makes a heck of a lot more sense to conclude that sensitivity is high, and there are no significant forcings we haven't thought of.
124577. kmcolo at 12:34 PM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Methane started to level off in early 1990s so not tight correlation with water vapor. Also, apparently (though I too am limited by article access issue) ∆ in strato-water vapor was in lower stratosphere thus not likely methane. All that said if there was a change in tropo-strato exchange then there might be noticeable change in atm concentrations of methane, SF6, etc. Worth looking into...
124578. Marcus at 11:38 AM on 1 February 2010
        The role of stratospheric water vapor in global warming
        Hmmm, as I recall, methane levels rose sharply through the 2nd half of the 20th century-but leveled off between 2000-2008. So maybe that's why there's a drop in stratospheric water vapor post-2000. However, as this additional methane was derived from human sources (sewerage, land fill, fossil fuel extraction, land-use change)-then the stratospheric water vapor contribution to global warming-small though it might be-might well still be ultimately of anthropogenic origin. That certainly doesn't let the contrarians off the hook!
124579. Tony O at 11:33 AM on 1 February 2010
        The role of stratospheric water vapor in global warming
        The article is hidden behind a pay-wall so I have to rely on the likes of yourself to interpret. Even if I could access the article there is no guarantee I could understand it. It is interesting. Thanks.
124580. Riccardo at 10:27 AM on 1 February 2010
        There's no empirical evidence
        samantha, it's basically the same, they just found it hard to get it through peer review.
124581. Marcus at 10:25 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        Also, I sincerely doubt that the amount of atmospheric warming which could be generated from an artificial lake can even remotely compare to the atmospheric warming that a greater than 100ppm rise in CO2 could cause.
124582. Marcus at 10:24 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        Um, its DAMS, not DAMNS-you only say DAMN if you're cussing ;).
124583. samantha at 09:30 AM on 1 February 2010
        There's no empirical evidence
        Riccardo Thanks for the link. I will look over it. BTW. The original paper is two years old, this paper is Jan2009.
124584. Riccardo at 08:57 AM on 1 February 2010
        It's Urban Heat Island effect
        pedex, i'm not an expert but there are a few things i know. Comparing the raw data has no meaning. Comparing adjusted data from two nearby stations, one rural and one urban, tells us that the UHI effects exists, which we all know and it's corrected for. Full analysis, with homogenization, averaging and gridding separately the data from urban and rural station would be requied, which i'm not able to do by my self and that you have not done either. I'm left with the published papers by professionals, in part referenced in this blog post. If ever someone will come up with a serious demonstration of the fault in the current analysis, which incidentally appears to be in agreement with satellite data (no UHI effect there), i'm ready to listen. For sure i'm not going to trust anyone who in its spare time play around with a computer and a bunch of meaningless (to him) numbers, the whole story is far more serious than just this.
124585. pedex at 07:01 AM on 1 February 2010
        It's Urban Heat Island effect
        Ive done some plots both ways, the old fashioned manual way and using the site I linked above, the result comes out the same. Rural stations tend to show no warming, urban stations do. It is especially evident in the US as well where there is lots of space between cities and lots of rural areas. Some places like the city where I live you can literally see the warming correlate with the development of the city where nearby rural stations show none at all. Like I said, plot some of your own and see what you get. Don't take my word for it or the word of this website because its arguments are pretty disingenuous in their own right from what I have seen.
124586. Riccardo at 06:45 AM on 1 February 2010
        It's Urban Heat Island effect
        pedex, strange that the missing data come mostly from the last few years. It may generate large errors also in the previous years. The very first step should be to check the code, no one is going to trust those numbers so blatantly wrong.
124587. pedex at 06:22 AM on 1 February 2010
        It's Urban Heat Island effect
        when a data point is missing an entry the ghcn data puts in a -9999 to show it, the software averaged that in and also tried to plot it which puts if off the chart its supposed to filter those out but for some reason it doesn't at the end of beginning of a plot sometimes
124588. Riccardo at 06:11 AM on 1 February 2010
        It's Urban Heat Island effect
        pedex, it's not only the running average that has that weird drop, the blu curve drops as well. There must be something wrong in how the data are processed. However, the simple average of stations doesn't tell you much. More so if you compare unadjusted data (the 778 stations) with adjusted data (the 173 stations).
124589. Doug Bostrom at 05:59 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        RSVP at 05:40 AM on 1 February, 2010 "The point here was not to condemn hydroelectric power, it was simply to state that even damns must be contributing in some way to global warming." What is really interesting about dams is the damping effect they've had on sea level rise. It is of course a temporary effect. More...
124590. RSVP at 05:40 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        Philippe Chantreau Just kidding that you advanced this idea, but your comment did hatch the thought. Think about the difference from snow melt discharging into the sea within a season vs. being held back all year in a damn. If incremental CO2 levels can make so much difference for narrow bands of IR, why not direct solar radiation trapped in incremental H2O? It may not be "causing" global warming, but it cant be helping. Now, as far as global warming, it may not be as bad as other forms of power generation, and the benefits to water supplies cannot be overlooked etc. The point here was not to condemn hydroelectric power, it was simply to state that even damns must be contributing in some way to global warming. (As far as salmon and trout. Damns completely mess up ecosystems and deter salmon from reach their spawning grounds. Special fish ladders have to be arranged, but damns on the whole have decimated natural fish populations. And yes, the water below damns can be cold when taken from the bottom, but the fish found there are planted for fishermen. )
124591. pedex at 05:38 AM on 1 February 2010
        It's Urban Heat Island effect
        just how the software cuts off at the end of the record, its normal when you do a running average like that software does you will see a messed up end and beginning of the graph if the data set is missing a value if you go to the noaa website and download the data you will see lots of stations that have data dropouts which when that software at the other website above gets one of those at the end or beginning of the graph it will blow up or in this case down, what is important is the long term trend ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/ you can plot all sorts of stuff from that data, temps gridded or not, adjusted or not, a couple data sets to choose from as well as precipitation amounts as well I think everyone should do a few, pick your home town and have a look, pick some rural stations and urban ones and graph them and see how they look. You might be surprised at what you see. I would also recommend just for your own sanity do a few single station plots and look up what the actual stats are for that station as far as where it is and what kind of quality it has. They are labeled as to what kind of local situation they are in like wooded or grassy plains etc etc.
124592. Riccardo at 05:16 AM on 1 February 2010
        It's Urban Heat Island effect
        pedex, what is that 9 °C drop in temperature in one of your graphs? Looks weird.
124593. pedex at 04:26 AM on 1 February 2010
        It's Urban Heat Island effect
        ^^typo, the exclusion should be after 2000 not 200
124594. pedex at 03:48 AM on 1 February 2010
        It's Urban Heat Island effect
        http://home.rr.com/pedex252 two graphs on that site, one is 177 urban stations using adjusted data from the GHCN data set with stations w/o data before 1930 and after 200 excluded the other is 778 rural stations with same exclusions sorry guys but the data disagrees with the explanation made here on this site and it matters not whether adjusted or unadjusted data is used all that matters is whether or not you pick urban or rural stations if you wish to make your own graphs then go here: http://www.appinsys.com/GlobalWarming/climate.aspx some of you should plot some for yourselves and see what you get instead of taking my word for it or anybody else's for that matter
124595. Philippe Chantreau at 03:27 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        Advancing what idea? Care to provide some scientific references? How seriously did you think about this RSVP? The water "sitting" during the winter actually has a lot more time to loose heat to the atmosphere and that's also the time where the water level will be the highest. However, the large thermal mass of an artificial lake makes it not so easy to warm or cool. During the spring, gathering melt water in large bodies is actually a excellent way to prevent it from warming. All in all, is there a net effect? How big can it possibly be? Considering the volumes released by dammed rivers and that of the oceans as whole, could this effect be measurable at the oceans' scale? Do you realize that the chance for the oceans to be be heated in any significant way by the "effect" you describe is so remote that the idea is downright ludicrous? And exactly how many "kinds of solar energy" can you list? Let me guess, you were joking, of course, silly me. You were, right? If you really wanted to do rethoric for its own sake, you could have gone about the CO2 related to concrete production, transportation, the "damns" construction process and what not. That would have been easier to exploit. Of course, then you'd have to exactly quantify that and come up with a number of years-equivalent-coal and try to convince that the "damns" weren't worth it, which they were. That wouldn't be OT either, since it is pretty close to the Monckton/Plimer style of "debate."
124596. Ian Forrester at 03:23 AM on 1 February 2010
        Lessons from the Monckton/Plimer debate
        RSVP said:

        Water in damns (sic) sits there picking up all kinds of solar energy and then gets released into the oceans.

        RSVP, you don't know very much about dams and the temperature of water in them. Anyone who is a fly fisherman in the western US will know about the world class trout fisheries which have established them selves down stream of a number of large dams. Previously, the water in these rivers had been too warm to support various trout species (the fish that western fly fishers are looking for) but after the dams were in use the water discharging through the turbines was very cold and supported both trout and the insects which the trout fed on. The best dams are the so called bottom discharge dams but other dams are helpful too. The water soon warms up down stream and the trout only inhabit a few miles of newly established prime habitat down stream from the damns. So much for your theory. Google "tailwater fisheries" to see how wrong you are.
124597. Riccardo at 00:47 AM on 1 February 2010
        Guest post in Guardian on microsite influences
        I didn't go through the paper accurately yet and maybe i will contradict myself later :). But there are a few things that i feel can already be stressed It is not on the water vapour feedback. Indeed, it focuses on the water vapour just in the lower stratosphere; it might have contributed to the slow down of the tropospheric temperature (as opposed to global warming) increse, but it's something related more to interannual/decadal variability than to the long term trend. The reason of the sudden drop in year 2000 is not clear. It might be related to the unusual warming of the western pacific ocean and the drop of the tropopause temperature. If this is linked to global warming or it is part of a natural cycle can not yet be assessed. As far as i know no one has looked at models behaviour as far as the lower stratospheric humidity is concerned. It's then hard to guess a possible physical mechanism responsible for its reduction and if it's a consequence of the already known physics. Gavin Schmidt at RealClimate promised further analysis, we'd better wait for more insights. As is standard practice in science, unless there are evident flaws in a paper (which seemes to be not the case here) it should be carefully evaluated taking the required time. No nails in the coffin nor smooking guns around, just one more little piece of evidence to fit in the global picture.
124598. Tom Dayton at 00:13 AM on 1 February 2010
        Guest post in Guardian on microsite influences
        Iodolite, Solomon's new stratospheric water vapor paper is discussed at RealClimate.
124599. lodolite at 22:44 PM on 31 January 2010
        Guest post in Guardian on microsite influences
        This is off topic but I can't find anyone discussing Susan Solomon's (NASA)new study showing that water vapour is decreasing in the stratosphere. She says that water vapour is acting as a negative feedback rather than amplyfiying CO2. http://www.guardian.co.uk/environment/2010/jan/29/water-vapour-climate-change says no one understands why its decreasing
124600. Gianfranco at 20:14 PM on 31 January 2010
        Trenberth can't account for the lack of warming
        Thank you very much for the excellent explanation. One point still puzzles me, though, perhaps because I’m Italian: the word “travesty”. According to my good old Oxford Dictionary it means “a description that intentionally misrepresents the original e.g. burlesque poem etc.” etymology being the Italian verb travestire = disguise. It somehow conveys the impression that the whole thing is a farce, a dress up, an attempt to deceive. I understand in private informal correspondence one doesn’t care much about wording, but, why didn’t he use pity or shame or bad luck?

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