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  • Something to save on my iMac desktop

    Originally posted by sylas View Post
    It's a pretty safe bet that the current pause won't last. It's possible (though not at all certain) that 2014 will be a new record high. I definitely expect that one of the next five years will show a very clear record high global surface temperature anomaly. But we'll see....

    Cheers -- sylas
    I have posted this so as to save it on my iMac desktop, just for fun.

    Now, all I have to do is to somehow manage to live to age 85 to see what happens in 5 years.

    2014 is half over, so I should be able to live long enough to see if 2014 reaches 'a new record high'.

    This should be interesting...

  • #2
    Hi John,

    I did something very similar in the old TWeb; where I predicted (guessed) that one of 2008/2009/2010 would set a new record. I set the terms of the bet to be unambiguous, by specifying the GISTEMP dataset, and noting that if at any point for a year after 2010 results were first published one of these years was not the highest value, then I'd lose. I estimated at the time about a 70% chance of winning.

    As it turns out, I lost. When the numbers first came out for 2010, I declared a win; but a subsequent tiny revision brought 2010 to a dead heat with 2005, and so I lost the bet as defined. No-one took up the bet; I simply put up $50 of my own money, and said I would either spend it on riotous living for myself, or donate it to TWeb. I made the donation, gladly. I couldn't get anyone to go along with me, however.

    Would you be interested in a repeat of some kind? Let's just make it a wait of less than a year.

    I propose we use the GISTEMP global anomaly figures (available here; look for the Global-mean monthly, seasonal, and annual means) and the J-D (January to December) annual mean, using the two decimal places accuracy with which it is published.

    I propose that if at the end of June 2015 there is an J-D annual average anomaly calculated for 2014 that is NOT the outright largest magnitude for the J-D anomaly in GISTEMP, then I lose; and I'll donate $50 to TWeb. Conversely if at the end of June 2015, the data shows 2014 has having the outright largest anomaly value in the J-D column -- then you get to donate $50 to Tweb.

    I'd feel fairly good about this bet; but certainly not totally confident. If an El Nino develops in time to give a slight rise in global anomalies, then I'd probably win. Otherwise, you'd be looking good. And the El Nino watch is at present only giving about 50% chance of El Nino developing in coming months.

    The average anomaly for the first half of 2014 is about 65 (units are in hundredths of a degree above a 1951-1980 reference norm). The record for a whole year is standing at 66. May 2014 recorded hot (hottest May ever in the record) at 76 but June actually dropped down to 62. I need it to come back up again to average about 68 or more over the rest of the year.

    Given the underlying warming trend, I don't need a strong El Nino effect for this; a weakish one should to the trick, I think. Next big El Nino will probably lead to a decisive hottest year; but in this case I'm betting on just edging out 2010/2005 in the second decimal place. Which I concede is not really a significant difference; but it does at least help give the lie to the curious claim being made by some that things are currently cooling.

    This would presume both of us are still alive, kicking, and active on Tweb at the end of June 2015 -- and that Tweb is still alive as well of course! (And I've got a bad cold at present )

    Cheers - sylas

    Comment


    • #3
      Originally posted by sylas View Post
      Hi John,

      I did something very similar in the old TWeb; where I predicted (guessed) that one of 2008/2009/2010 would set a new record. I set the terms of the bet to be unambiguous, by specifying the GISTEMP dataset, and noting that if at any point for a year after 2010 results were first published one of these years was not the highest value, then I'd lose. I estimated at the time about a 70% chance of winning.

      As it turns out, I lost. When the numbers first came out for 2010, I declared a win; but a subsequent tiny revision brought 2010 to a dead heat with 2005, and so I lost the bet as defined. No-one took up the bet; I simply put up $50 of my own money, and said I would either spend it on riotous living for myself, or donate it to TWeb. I made the donation, gladly. I couldn't get anyone to go along with me, however.

      Would you be interested in a repeat of some kind? Let's just make it a wait of less than a year.

      I propose we use the GISTEMP global anomaly figures (available here; look for the Global-mean monthly, seasonal, and annual means) and the J-D (January to December) annual mean, using the two decimal places accuracy with which it is published.

      I propose that if at the end of June 2015 there is an J-D annual average anomaly calculated for 2014 that is NOT the outright largest magnitude for the J-D anomaly in GISTEMP, then I lose; and I'll donate $50 to TWeb. Conversely if at the end of June 2015, the data shows 2014 has having the outright largest anomaly value in the J-D column -- then you get to donate $50 to Tweb.

      I'd feel fairly good about this bet; but certainly not totally confident. If an El Nino develops in time to give a slight rise in global anomalies, then I'd probably win. Otherwise, you'd be looking good. And the El Nino watch is at present only giving about 50% chance of El Nino developing in coming months.

      The average anomaly for the first half of 2014 is about 65 (units are in hundredths of a degree above a 1951-1980 reference norm). The record for a whole year is standing at 66. May 2014 recorded hot (hottest May ever in the record) at 76 but June actually dropped down to 62. I need it to come back up again to average about 68 or more over the rest of the year.

      Given the underlying warming trend, I don't need a strong El Nino effect for this; a weakish one should to the trick, I think. Next big El Nino will probably lead to a decisive hottest year; but in this case I'm betting on just edging out 2010/2005 in the second decimal place. Which I concede is not really a significant difference; but it does at least help give the lie to the curious claim being made by some that things are currently cooling.

      This would presume both of us are still alive, kicking, and active on Tweb at the end of June 2015 -- and that Tweb is still alive as well of course! (And I've got a bad cold at present )

      Cheers - sylas
      Given the fact that I am an ignoramus with regard to science, I would have been more comfortable just waiting to see if your prognostication turned out as you originally suggested; however, I can still do that and also agree to the bet that you propose, and accept your terms, just for the heck of it.

      What do you suggest in terms of a wager?

      Comment


      • #4
        Originally posted by John Reece View Post
        Given the fact that I am an ignoramus with regard to science, I would have been more comfortable just waiting to see if your prognostication turned out as you originally suggested; however, I can still do that and also agree to the bet that you propose, and accept your terms, just for the heck of it.
        I guess I probably do have a better familiarity with the underlying science, but all it tells me for the moment is that this wager is pretty close to a crapshoot.

        The terms are simple. Neither of us makes a profit from this; and TWeb is assured a win. Assuming we're all around at the end of June 2015, then Tweb gets a donation of $US 50. The only thing to be resolved is... which of us makes the donation?

        We'll look at that data set, and if 2014 happens to be the absolute hottest year on record then you get to donate. If 2014 is not the hottest, then I get to donate. (So if 2014 ties for equal hottest with 2005/2010, then I get to make the donation.)

        The reason for this is pretty much for the heck of it... and to maintain an interest in the topic for anyone else following along as well!

        Cheers -- sylas

        Comment


        • #5
          Originally posted by sylas View Post
          I guess I probably do have a better familiarity with the underlying science, but all it tells me for the moment is that this wager is pretty close to a crapshoot.

          The terms are simple. Neither of us makes a profit from this; and TWeb is assured a win. Assuming we're all around at the end of June 2015, then Tweb gets a donation of $US 50. The only thing to be resolved is... which of us makes the donation?

          We'll look at that data set, and if 2014 happens to be the absolute hottest year on record then you get to donate. If 2014 is not the hottest, then I get to donate. (So if 2014 ties for equal hottest with 2005/2010, then I get to make the donation.)

          The reason for this is pretty much for the heck of it... and to maintain an interest in the topic for anyone else following along as well!

          Cheers -- sylas

          Comment


          • #6
            Originally posted by John Reece View Post
            Now, all I have to do is to somehow manage to live to age 85 to see what happens in 5 years.
            I pray that you do John...
            Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

            https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

            Comment


            • #7
              Originally posted by seer View Post
              I pray that you do John...
              Thanks! And my wife thanks you!

              Comment


              • #8
                sylas, how does James Hansen's GISTEMP compare with Roy Spencer's UAH as sources of temperature data?
                Last edited by John Reece; 08-12-2014, 01:17 PM.

                Comment


                • #9
                  Originally posted by John Reece View Post
                  sylas, how does James Hansen's GISTEMP compare with Roy Spencer's UAH as sources of temperature data?
                  They are measuring different things; closely related, but still different. GISTEMP (and a number of other major data sets, like HadCRUT4 and MLOST) measure the temperature at Earth's surface: or more precisely, the skin of air in direct contact with the surface. The UAH data is measuring the lower troposphere, or the bottom of the atmosphere: roughly up to 5km or so.

                  With the respect to the wager: I'd be happy to use any major dataset for the surface temperature as the basis, but if we were to UAH data for the lower troposphere, then I'd want to look at 2015, not 2014, for a possible new high value.

                  The discussion following will explain why.

                  Quick and dirty comparison of the datasets

                  The two sets of data are strongly correlated to each other. The main difference to my eye seems to be that the atmospheric temperature shows larger swings. This makes sense to me physically. Air has comparatively low heat capacity and so can heat up or cool down more than the surface. At the surface, the ground and the ocean act to damp out the swings and give less variation.

                  Here's a side by side plot of the two datasets (my own spreadsheet calculation, using annual data, and aligning vertically so they have the same mean value over 2001-2013). I've also plotted the difference.
                  GISSandUAH.png

                  As you can see, they are strongly correlated, but the GISS data has smaller swings. You get very much the same result using any of the other major surface temperature datasets (from Hadley Centre UK, or NCDC, or BEST) in place of GISS and/or using the other lower atmosphere dataset from Remote Sensing Systems.

                  Satellite temperature measurements

                  Satellites measure temperature indirectly, by measuring microwave radiation and inferring temperatures based on the thermal emissions from the atmosphere. By using different frequencies and using the known emissivity for atmospheric gases, it is possible to infer temperatures for different levels in the atmosphere. Typically, 4 levels are given; both in the UAH analysis (which Spencer works on) and the RSS analysis. (Remote Sensing Systems is another group doing independent calculations from the same satellite data.) Here's a diagram showing how temperature at different altitudes contributes to each of the four channels that are published.
                  msu_wt_func.png
                  (Source: Remote Sensing Systems)

                  UAH, and RSS, give temperature data for four different altitudes: lower troposphere (TLT), mid troposphere (TMT), troposphere/stratosphere boundary (TTS), and lower stratosphere (TLS). They all have significantly different trends; in particular the enhanced greenhouse effect leads to cooling of the stratosphere.

                  Since satellites are well above the atmosphere, all the signals they measure come through the stratosphere, which means that direct inference from any microwave channel will be impacted by stratospheric cooling and will fail to track well with surface temperatures. A major contribution of the team at UAH was to develop a new synthetic channel (TLT, the one which compares well with surface temperatures) which is obtained using a lot of hairy calculations, based on combining information from all the other channels and also views of the Earth at oblique angles, to filter out as much of the stratospheric impact as possible. RSS now also uses similar techniques to give a TLT product as well.

                  There are all kinds of other difficulties which much be managed to obtain useful temperature data; orbit decay, instrument heating, diurnal precession, and lots more. It's a lot more complex than figuring temperatures from measurements made directly at the surface; though that of course also has its own set of difficulties for processing.

                  There have been quite a few changes in processing over the years, fixing up various errors and problems. That's a fascinating story in itself; but more importantly the story is probably not yet over. All temperature calculations (surface and satellite) are continually subject to revision with changes in processing methods; and all the groups document the changes in analysis method. But I think the satellite data is more susceptible to this, due to the processing complexities, and the differences in the methods applied by RSS and UAH.

                  What data should be the basis of our little wager?

                  My suggestion was for surface temperature, not lower troposphere temperature. Beyond that, I'd be happy to use any of the major datasets available. James Hansen is not in fact involved with GISSTEMP any longer, though he was the head of the GISS group until quite recently. But still, if you prefer to use another surface temperature set, there are a couple of alternatives.
                  • HadCRUT4, by the Met Office Hadley Center in the UK.
                  • MLOST, by National Climatic Data Center in the US.
                  • BEST, by Berkerley Earth Surface Temperature.

                  I'd be happy to use any of these; the differences with GISS data are very small, and they are all attempting to measure the same thing.

                  Using satellite data would be a different matter entirely, mainly because the lower troposphere has such a strong response to the ENSO cycle. The EL Nino of 1998 was huge, and all the satellite data still has that as the highest value recorded on the TLT channel. The next closest peak is with the EL Nino of 2010.

                  In my view, it is highly unlikely that 2014 will be able to set a new record for TLT. Air temperatures rise some months after the beginning of an El Nino. This means that the conventional surface temperature is only likely to get a new high value if an El Nino develops fairly soon. But for the TLT satellite measurement, a new record is going to require a much more solid El Nino contribution. This could quite likely show up in 2015 -- if the El Nino does develop strongly enough. But it really really unlikely for 2014.

                  An added wrinkle is that there are two datasets we could use. There's UAH which you are asking about. And then there's the similar product from RSS. But there's enough difference between these two sets to make a major difference in the wager. Since about 1998, RSS has been running steadily slower than UAH; this shows up by looking at the trend over the last 17 years.

                  Here's the data comparison:
                  RSSandUAH.jpg
                  The trend (over 17 years from 1997 to 2013 inclusive) is:
                  • RSS: -0.13 +/- 1.44
                  • UAH: +0.94 +/- 1.46

                  Values are degrees per century, and the error bounds are using simple linear regression bounds at 95% confidence limits... again, my own calculation.

                  In both cases, the trend is less then the confidence limits. Atmospheric temperature data, because of its large swings, will always have more uncertainty for trend, and 17 is not enough to get a trend with significance. The confidence limits are so large that the data is consistent both with strong warming and strong cooling trends.

                  The trend for surface temperature, calculated over the same 17 years and the same confidence limits, are as follows:
                  • GISS: +0.71 +/- 0.79
                  • HadCRUT4: +0.49 +/- 0.77
                  • MLOST: +0.44 +/- 0.66
                  • BEST: +0.85 +/- 0.85

                  All show warming but not statistically significant.

                  If you are concerned with using the GISS data, I'm quite happy to use the MLOST product instead, from the NCDC (National Climatic Data Center). Although it shows a smaller trend, the two datasets are very close, and measuring the same thing. So it makes no difference as far as I am concerned.

                  Cheers -- sylas

                  Comment


                  • #10
                    Sylas, an interjection if you and John don't mind: Was it you who said to me once that we are in an interglacial warming period of the current Ice Age?

                    (I can't remember who I had the discussion with)
                    "If you can ever make any major religion look absolutely ludicrous, chances are you haven't understood it"
                    -Ravi Zacharias, The New Age: A foreign bird with a local walk

                    Be watchful, stand firm in the faith, act like men, be strong.
                    1 Corinthians 16:13

                    "...he [Doherty] is no historian and he is not even conversant with the historical discussions of the very matters he wants to pontificate on."
                    -Ben Witherington III

                    Comment


                    • #11
                      Originally posted by Raphael View Post
                      Sylas, an interjection if you and John don't mind: Was it you who said to me once that we are in an interglacial warming period of the current Ice Age?
                      Very likely. It's a true statement in any case, though better "interglacial warm period", not "interglacial warming period".

                      The warming out of the most recent glaciation took place roughly 11,000 years ago, and the "Holocene optimum", or warmest period of the current interglacial, was some 8000 years ago. Since then has been a long very slow cooling trend -- as is normal for interglacial warm periods. Though, of course, that has turned around sharply last century.

                      Cheers -- sylas

                      Comment


                      • #12
                        Originally posted by sylas View Post
                        Very likely. It's a true statement in any case, though better "interglacial warm period", not "interglacial warming period".

                        The warming out of the most recent glaciation took place roughly 11,000 years ago, and the "Holocene optimum", or warmest period of the current interglacial, was some 8000 years ago. Since then has been a long very slow cooling trend -- as is normal for interglacial warm periods. Though, of course, that has turned around sharply last century.

                        Cheers -- sylas
                        Thank-you
                        "If you can ever make any major religion look absolutely ludicrous, chances are you haven't understood it"
                        -Ravi Zacharias, The New Age: A foreign bird with a local walk

                        Be watchful, stand firm in the faith, act like men, be strong.
                        1 Corinthians 16:13

                        "...he [Doherty] is no historian and he is not even conversant with the historical discussions of the very matters he wants to pontificate on."
                        -Ben Witherington III

                        Comment


                        • #13
                          But is it going to rain tomorrow? I say, 'yes'!
                          βλέπομεν γὰρ ἄρτι δι᾿ ἐσόπτρου ἐν αἰνίγματι, τότε δὲ πρόσωπον πρὸς πρόσωπον
                          ἄρτι γινώσκω ἐκ μέρους, τότε δὲ ἐπιγνώσομαι καθὼς καὶ ἐπεγνώσθην.

                          אָכֵ֕ן אַתָּ֖ה אֵ֣ל מִסְתַּתֵּ֑ר אֱלֹהֵ֥י יִשְׂרָאֵ֖ל מוֹשִֽׁיעַ׃

                          Comment


                          • #14
                            Originally posted by sylas View Post
                            So it makes no difference as far as I am concerned.
                            Me neither; I was merely curious.

                            Comment


                            • #15
                              Originally posted by John Reece View Post
                              Originally posted by sylas
                              So it makes no difference as far as I am concerned.
                              Me neither; I was merely curious.
                              Sure! ... but just to clarify if people read this without looking at the rest of my (overlong!) answer...

                              "It" in my quoted sentence refers to the difference between two surface temperature datasets, by GISS, and NCDC.

                              By way of contrast, it does make a big difference if we use a lower troposphere dataset (UAH or RSS) rather than a surface temperature dataset (GIStemp, MLOST, BEST, or HadCRUT4).

                              So with respect to the original question you asked... how does GIStemp and UAH compare as sources of data: GIStemp and UAH are significantly different, sufficiently so as to mean I would not make the same wager using UAH.

                              Cheers -- sylas
                              Last edited by sylas; 08-13-2014, 11:07 AM.

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