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Thanks Stas, that's interesting. So it is the cooler bits (nights) that are getting warmer, not the hotter bits. That seems to be REDUCING variability which is generally regarded as a good thing (but might not be in this case). Is there any data indicating how much of the average increase is night-time increase and how much is daytime? e.g. if the average is 4 degrees, this could be 5 at night and 3 during the day, or it could be 6+2 or 7+1 or even 8+0 (if these averages work the way I feel they should, which they may not). Thanks for your information. JOHN On 28 September 2013 14:35, Stas Kolenikov <[log in to unmask]> wrote: > So far the primary mechanism of the warming was that the nights were > getting warmer -- the heat cannot escape the greenhoused atmosphere of > the Earth. The daily high temperatures have not moved as much as the > nightly temperatures have: this is just the amount of solar energy > that reaches Earth, and it has not changed that much. The seasons are > here to stay, but given that heat imbalances increase, there will be > more extremes as a manifestation of that loss of balance. > > -- Stas Kolenikov, PhD, PStat (ASA, SSC) > -- Senior Survey Statistician, Abt SRBI > -- Opinions stated in this email are mine only, and do not reflect the > position of my employer > -- http://stas.kolenikov.name > > > > On Sat, Sep 28, 2013 at 7:16 AM, John Bibby > <[log in to unmask]> wrote: > > So global warming is going up by 3.7 degrees (today's Guardian p.17; > "extra > > global warming likely between 2081 and 2100"). > > > > I don't want to doubt that, but how should it be interpreted? > > > > As an average presumably, but what sort of average? > > > > No, I don't mean mean, mode or median as per that Stats 100 course we > once > > studied - I mean how are we to interpret that average? lt's an average > over > > time and space presumably. (I leave aside the question of variability, > which > > is generally far more interesting and/or dangerous than the average. > After > > all, we can plan for well-predicted averages, as these are. But > unpredicted > > tail-values are far more difficult, esp. if we do not know where and when > > they will fall.) > > > > So let's focus on me in York. If the temperature goes up by 3.7 degrees, > > that could be 3.7% every day and night for the whole day and night i.e > the > > profile stays exactly the same; it just lifts up by 3.7 degrees. > (Unlikely, > > but ok maybe as a first-step thought-experiment.) > > > > Far more likely however (I guess) is a switch between the seasons i.e. we > > might get more 'summery' days and fewer 'wintery' days. > > > > So what I'd like to know is (a) typical temperatures for 'summer' and > > 'winter', and (b) how much of a shift would be needed to reach the > required > > temperature rise. A back-of-my-brain calculation led me to think that if > > 'summer' means 30 degrees, and 'winter' means 10 degrees, and if at > present > > the ratio is 1 to 1, then an increase of 3.7 degrees corresponds to a > ratio > > of roughly 1.6 to 1 i.e. more summer, less winter. Put that way, it does > > not sound so scary. > > > > However, my data may be flawed. Or my thinking may be flawed. Or my > politics > > may be flawed. Or (probably) all three. > > > > Can anyone please put me on the straight-and-narrow so I c an sing from > the > > same hymn-sheet as the rather incompehensible green-buffs whom I heard on > > the radio yesterday. > > > > Thanks to anybody who has read this far. (I never did understand or > > believe in hymns - but I do like to sing-along!) > > > > JOHN BIBBY > > > > > > You may leave the list at any time by sending the command > > > > SIGNOFF allstat > > > > to [log in to unmask], leaving the subject line blank. > > You may leave the list at any time by sending the command > > SIGNOFF allstat > > to [log in to unmask], leaving the subject line blank. > You may leave the list at any time by sending the command SIGNOFF allstat to [log in to unmask], leaving the subject line blank.