tag:blogger.com,1999:blog-9959776.post8134404183166311664..comments2024-02-15T04:42:41.606+00:00Comments on James' Empty Blog: Not so fast!James Annanhttp://www.blogger.com/profile/04318741813895533700noreply@blogger.comBlogger42125tag:blogger.com,1999:blog-9959776.post-4078455171703621612012-03-22T01:05:20.991+00:002012-03-22T01:05:20.991+00:00I did actually pay up, because the HC did initiall...I did actually pay up, because the HC did initially publish the HadCRUT3 analysis for 2011. Perhaps a more honourable opponent would consider the bet void, given the premise (of 1998 not having been beaten when we made it) is now clearly seen to have been invalid.<br /><br />Of course, I'm not holding my breath.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-28129885860726893052012-03-21T16:17:39.940+00:002012-03-21T16:17:39.940+00:00> "Even if you retrospectively apply"...> "Even if you retrospectively apply"<br /><br />Interesting phase. If you are suggesting that James has paid up but now want his money back twice over then you would have a strong point. If however the bet is still unsettled, then you either use the data specified or the latest data. <br /><br />IMO David Whitehouse is in a much weaker position now. He should have pushed for settlement as soon as HadCRUT3 Dec 11 data was published.<br /><br />Is it clear whether the wording was new annual temperature record or temperature higher than 1998 between 2008 and 2011 inclusive? <br /><br />If it clearly was a new record then James is perhaps being naughty referring to it being all about since 1998. But if the wording wasn't sorted when James tried (assuming he did) then maybe DW should get what he deserves.crandleshttps://www.blogger.com/profile/15181530527401007161noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-41179238163329529742012-03-19T18:59:35.951+00:002012-03-19T18:59:35.951+00:00According to Hadcrut4 2010 has a temp anomaly of 0...According to Hadcrut4 2010 has a temp anomaly of 0.53. So does 2005. Errors are 0.1.<br /><br />Even if you retrospectively apply the climate bet to HadCrut4 (and who in their right mind retrospectively applies bets) I would have still won because no new record was achieved by 2011.Unknownhttps://www.blogger.com/profile/01185098814068849545noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-7179023914676910032012-03-19T18:32:41.342+00:002012-03-19T18:32:41.342+00:00published in JGR?
http://www.bbc.co.uk/news/scien...published in JGR?<br /><br />http://www.bbc.co.uk/news/science-environment-17432194crandleshttps://www.blogger.com/profile/15181530527401007161noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-1656225158001755192012-02-06T06:36:05.140+00:002012-02-06T06:36:05.140+00:00http://www.forbes.com/sites/petergleick/2012/02/05...http://www.forbes.com/sites/petergleick/2012/02/05/global-warming-has-stopped-how-to-fool-people-using-cherry-picked-climate-data/Hank Robertshttps://www.blogger.com/profile/07521410755553979665noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-6044285009931550352012-01-31T08:09:40.511+00:002012-01-31T08:09:40.511+00:00Yes, that's not the Morice et al paper that we...Yes, that's not the Morice et al paper that we are all waiting for...HadCRUT3 is still the official record.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-24699930012150937812012-01-30T21:54:18.840+00:002012-01-30T21:54:18.840+00:00Ahh it's the land-only CRUTEM4... they haven&#...Ahh it's the land-only CRUTEM4... they haven't finished the merged product yet.doskonaleszarehttps://www.blogger.com/profile/07347089891701103321noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-5801990725029003532012-01-30T21:52:07.842+00:002012-01-30T21:52:07.842+00:00FIY, HadCRUT4 is PIP at JGR (acronym overload!)
h...FIY, HadCRUT4 is PIP at JGR (acronym overload!)<br /><br />http://www.agu.org/pubs/crossref/pip/2011JD017139.shtmldoskonaleszarehttps://www.blogger.com/profile/07347089891701103321noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-31895587528158159732012-01-21T11:36:40.319+00:002012-01-21T11:36:40.319+00:00Iced Vovo:
When Hadley/Jones et al are completely...Iced Vovo:<br /><br /><i>When Hadley/Jones et al are completely transparent with the RAW data and algorithms then HADCRUT might be taken seriously by other than the IPCC converted.</i><br /><br />Actually, HADCRUT is the dataset of choice by fake sceptics who like to say there has been no warming since 1998. They couldn't be choosing the dataset based on the result it gives, surely.Electrical Engineerhttps://www.blogger.com/profile/02801052287045859151noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-70676586229310745202012-01-21T03:05:39.257+00:002012-01-21T03:05:39.257+00:00Carrick: read the press release AGAIN! They are no...Carrick: read the press release AGAIN! They are not releasing the RAW data; rather they are releasing the "massaged" data. Further no station ID or position data will be available! <br /><br />Even disregarding the climate gate emails which clearly show collusion to "massage" data the lack of ability to verify results is a breach of all the basic principles of science! <br /><br />So what I said stands: I DONT TRUST THE CRU!IcedVolvohttps://www.blogger.com/profile/10789298012152722182noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-46031905725316780322012-01-20T06:58:51.533+00:002012-01-20T06:58:51.533+00:00Since temperatures go up by including the upper Ar...<i>Since temperatures go up by including the upper Arctic, it is obvious that the rest of the world, and especially the inhabited regions, have not warmed as expected.</i><br /><br />No, the rest of the world was expected to warm less rapidly than the upper Arctic.Electrical Engineerhttps://www.blogger.com/profile/02801052287045859151noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-38510496592251581732012-01-19T17:58:54.936+00:002012-01-19T17:58:54.936+00:00Maurizo: in fact if we take HadCRUT4 and remove th...Maurizo: <i>in fact if we take HadCRUT4 and remove the new Arctic and Russian sites, we get HadCRUT3 and a lower trend.</i><br /><br />I'd predict by maybe as much as 0.004°C/decade. <br /><br />Interesting from a "seeing how many thermometers you can fit on the head of a pin" perspective, but policy wise, it's inconsequential...<br /><br />which is really what I was suggesting.<br /><br />It, is by the way, possible to compute the global temperature trend in a way that is robust against adding or dropping stations over time. (I'm thinking of something more than just 5°x5° gridded average.)<br /><br />The trick is in deciding it is trend you are interested in measuring, and in recognizing and factoring in the latitudinal bias in temperature trend associated with arctic amplification. (Something similar to pre-whitening.)Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-72407913905060884962012-01-19T16:57:21.231+00:002012-01-19T16:57:21.231+00:00Thank you Carrick...however my point was not about...Thank you Carrick...however my point was not about the effect of adding sites at lower latitudes, rather the effect of removing sites at higher ones...in fact if we take HadCRUT4 and remove the new Arctic and Russian sites, we get HadCRUT3 and a lower trend.Maurizio Morabitohttps://www.blogger.com/profile/10852130802624554276noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-14051279422536484282012-01-19T15:31:06.337+00:002012-01-19T15:31:06.337+00:00Maurizo: Since temperatures go up by including the...Maurizo: <i>Since temperatures go up by including the upper Arctic, it is obvious that the rest of the world, and especially the inhabited regions, have not warmed as expected.</i><br /><br />Em... there's a decent theoretical argument for why you'd expect more warming (or cooling) at the North Pole (arctic amplification). That's not to say the magnitude is fully understood, but the fact that it happens isn't unexpected.<br /><br />Secondly, <a href="http://dl.dropbox.com/u/4520911/Climate/temperature_trends.jpg" rel="nofollow">if you look at temperature trends, </a> you find the dominant effect is from a) latitude and b) whether you are at a marine (or coastal) site versus and in-land site. Regarding latitudinal bias on land, what you find is below 30°N, there isn't much variation in trend. <br /><br />Adding more sites at lower latitude may reduce your noise slightly, because it mashes down temperature variability associated with site selection, but it isn't going to change your trend estimate in any meaningful way. It is easy to see from these sorts of analysis, that the biggest uncertainty comes from undersampling latitudinal bands, especially those of the high arctic, so not under-sampling by adding in more stations does help improve the accuracy of the reconstruction slightly.<br /><br />As I pointed out upthread, the effect of adding the additional sites on Hadcrut is actually quite minute. It may matter for bets made on central values (and parlor style arguments). <br /><br />Here are the trends from the current "big four" reconstructions (°C/decade), 1980-2009 inclusive:<br /><br />ECMWF 0.164<br />NCDC 0.167<br />HADcrut3gl 0.163<br />GISTEMP 0.165<br /><br />The largest difference in trend amounts to only 0.004°C/decade or 0.04°C change in a century. This is likely inside the measurement uncertainty associated with the reconstruction algorithm. (As opposed to the larger uncertainty associated with the effect of short-period climate on your estimate of central trend, which is much larger, but doesn't affect the differences in reconstruction trends at first order.)<br /><br />While it is interesting scientifically why HADcrut3 is lower than GISTEMP, I would argue there are no policy-related ramifications from the fact that they even differ.Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-25113995671890312512012-01-19T14:37:31.953+00:002012-01-19T14:37:31.953+00:00It's really really hard to avoid laughing when...It's really really hard to avoid laughing when adjustments come out of thin air but anyway...let's consider HadCRUT4 less of a joke for a moment.<br /><br />Since temperatures go up by including the upper Arctic, it is obvious that the rest of the world, and especially the inhabited regions, have not warmed as expected.<br /><br />And a 5C increase in an area where the average is -20C is _not_ the same thing as a 5C increase where the average is +10C. The former is inconsequential, the latter a change in all seasons.<br /><br />So HadCRUT4 simply confirms things are going as predicted only in faraway places where there are few measurements and nothing is really changing anyway.Maurizio Morabitohttps://www.blogger.com/profile/10852130802624554276noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-55726330079773670602012-01-19T14:24:52.537+00:002012-01-19T14:24:52.537+00:00IcedVolvo: Gee lets think about whether we trust ...IcedVolvo: <i> Gee lets think about whether we trust the Hadley CRU data; well lets see; they wont let anyone have access to the RAW data to verify the results, and I am pretty sure Jones reported that the original data was "lost</i><br /><br />Lost data is not going to be a problem. From <a href="http://www.metoffice.gov.uk/media/pdf/9/s/MOSAC_16.4.pdf" rel="nofollow">The Met Center</a>:<br /><br /><i>The underlying data used to generate the new HadCRUT4 dataset will be free from any restrictions to public distribution when the dataset is released.</i>Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-74941707533365067832012-01-19T09:54:20.382+00:002012-01-19T09:54:20.382+00:00If I understand this correctly, despite a shortage...If I understand this correctly, despite a shortage of Artic temperature stations with at least 15 years of data between 1961-90 - that's all HadCRUT3 requires! - someone figures they can estimate what it would have have been for each month.<br /><br />Mind you, all of the HadCRUT3 data is an estimate because it's not based on mean temperatures but just the mean of the mean maximum and mean minimum for the month - an averaging technique not used in any other branch of science.John Mhttps://www.blogger.com/profile/02008883558358212178noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-62278221418479342692012-01-18T23:31:36.578+00:002012-01-18T23:31:36.578+00:00Gee lets think about whether we trust the Hadley C...Gee lets think about whether we trust the Hadley CRU data; well lets see; they wont let anyone have access to the <b>RAW</b> data to verify the results, and I am pretty sure Jones reported that the original data was "lost". The "correction" algorithms are a state secret. The integrity of the dataset has been questioned over and over again with no detailed analysis as to what goes in and what gets left out. No surprises HADCRUT 4 supports the dogma!<br /><br />When Hadley/Jones et al are completely transparent with the <b>RAW</b> data and algorithms then HADCRUT might be taken seriously by other than the IPCC converted.IcedVolvohttps://www.blogger.com/profile/10789298012152722182noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-73299083733417054472012-01-18T16:45:19.748+00:002012-01-18T16:45:19.748+00:00Screwed up my link.
Heres' the Monte Carlo ba...Screwed up my link.<br /><br /><a href="http://dl.dropbox.com/u/4520911/Climate/Mean_Trend_Error.jpg" rel="nofollow">Heres' the Monte Carlo based error analysis I was referring to.</a>Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-54606023847608646992012-01-18T16:31:31.616+00:002012-01-18T16:31:31.616+00:00James: Incidentally, it is not at all clear from t...James: <i>Incidentally, it is not at all clear from the graph what the error on the difference between two years is, as many of the errors are temporally correlated.<br /></i><br /><br />Well, of course that can be calculated (using reasonable assumptions about the underlying noise such as homoscedasticity), but this does expose a major weakness to using "records" (individual data points) to argue over <i>trends</i> (which I would argue is what eventually we really care about). <br /><br />The uncertainty in the difference between the two data points in general doesn't improve by changes the separation between two points (there are exceptions, e.g., correlated noise that decorrelates as the interval between points increases).<br /><br />On the other hand, if you compute the trend using OLS, for example, as the interval is increased, the rejection of short-period noise is improved. (This is the sort of curve I get using a Monte Carlo based approach... shown for comparison are results for four different methods generated by Lucia using e.g. ARIMA models of noise).<br /><br />If I were to enter into what I considered a reasonable bet, it would involve (at the minimum) whether the <i>sign</i> of the temperature trend was positive or negative. In fact you could use this sort of model-based calculation of uncertainty to figure out your odds. If we assume 0.2°C/decade, even 20 years isn't a safe bet.Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-9944168374675554342012-01-17T23:06:22.290+00:002012-01-17T23:06:22.290+00:00Carrick, I don't believe it is in principle no...Carrick, I don't believe it is in principle not interesting to scientists. There is lots of academic work on extremes and record-breaking, and by its nature this cannot generally consider significance in this way, or else there is never a new record since the current best is almost never broken by a "significant" margin.<br /><br />Incidentally, it is not at all clear from the graph what the error on the difference between two years is, as many of the errors are temporally correlated.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-54269332800390038492012-01-17T23:02:16.845+00:002012-01-17T23:02:16.845+00:00Chris, I'm not rushing to judgement. AIUI the ...Chris, I'm not rushing to judgement. AIUI the HC hasn't actually released their analysis for 2011.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-59338011386782369722012-01-17T15:19:26.914+00:002012-01-17T15:19:26.914+00:00James: But the topic was never on the difference b...James: <i>But the topic was never on the difference being "statistically significant" (which is not proof of anything anyway)</i><br />Well, agreed, it's not "proof" (otherwise there wouldn't be so many 3+ sigma results that turned out to be wrong). But "statistical significance" is our usual standard for making generalizations from data, e.g.. whether any warming or cooling is statistically significant.<br /><br />I get the point of using the central value for the bet...but as you can tell I find that vexing. Mostly because it leads to an enormous amount of interest from "citizen scientists" in something that isn't at all interesting scientifically.<br /><br /><i> I don't think it is fair to say that they went looking for data in hot areas - there are additional grid cells filled in in colder areas too. It is not interpolation, but the use of more observations</i><br /><br />That's a good way of thinking about this. Thanks.Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-49823839775200790572012-01-17T14:26:25.727+00:002012-01-17T14:26:25.727+00:00>"you are right I did not expect to win in...>"you are right I did not expect to win in this manner."<br /><br />Does this mean you are claiming victory and refusing to pay up?<br /><br /><br />Meanwhile,<br />Arctic warming, increasing snow cover and widespread boreal winter cooling:<br /><br /><a href="http://iopscience.iop.org/1748-9326/7/1/014007/pdf/1748-9326_7_1_014007.pdf" rel="nofollow">pdf</a><br /><br />Should we expect further cooling of US & Eurasia over coming decade(s)? Is wondering if this could slightly reduce rate of global average temperate increase attaching too much importance to it? Or is there only so far the AO can be forced making future predictions about it rather speculative?<br /><br />How important might unknowns like this have been in your win/loss?crandleshttps://www.blogger.com/profile/15181530527401007161noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-69605333998568564262012-01-17T06:17:06.050+00:002012-01-17T06:17:06.050+00:00But the topic was never on the difference being &q...But the topic was never on the difference being "statistically significant" (which is not proof of anything anyway), just on whether the central estimate was higher or lower. I realise that of course this is of little scientific value, but it does appear to be of some public interest.<br /><br />I don't think it is fair to say that they went looking for data in hot areas - there are additional grid cells filled in in colder areas too. It is not interpolation, but the use of more observations. However, given the obvious spatial coherence of anomalies, interpolation would be an obvious approach to take, and I'm rather surprised they haven't yet done this. They already average over 5x5 degree grid boxes, which relies on the same principle, only in a less precise and justifiable manner. There have been more accurate and sophisticated methods out there for decades. OTOH they may view bias correction and inhomogeneity as more of a priority than spatial averaging. The global mean is a bit of a byproduct that most scientists don't even use - direct comparison of the spatial pattern is more common and informative.James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.com