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Discussion > What's the Dominant Sub-trend in Temp Rise since LIA ?

maxima ? minima ? summer ? winter ? etc. (direct link to latest comment page)

Started by @SimonJ Aug 8, 2016 at 12:45 PM
>> Since there is a definite hint of tumbleweed round here at the moment, perhaps people are available to enlighten me/everyone about a question I've been asking myself for quite a while, but have got no (sensible) reply yet.
We all (pretty well all) agree that global average temperatures have risen since the Little Ice Age. They have even risen since the 50s/60s.

My question is, in what manner have they risen?
The average is derived from daily min and max from weather stations all around the world, measured throughout the year.
The observed rise could have been achieved by ALL readings going up by the increase. I find this very unlikely. Or, the maxima could all have gone up by twice the increase, or the minima etc etc. You see where I'm going.

So, my question (got there at last) is, has anyone analysed the vast number of readings to see if there is any predominant mechanism to account for the increase?
Is it mostly accounted for by a rise in minima? or a rise in maxima? Is the rise mainly in winter, summer, any other time of year?
It just shows what a piss-poor metric the 'global average' is for any sort of analysis.
In anticipation <<

Aug 8, 2016 at 1:11 PM | Registered Commenterstewgreen

Entropic man commented

In summary.

Nights are warming faster than days.

Winters are warming faster than Summers.

The further North you go, the faster the warming.

(I think that 's @EM's informed opinion for recent times..I don't know if that applies to 10, 50, 100, 500+ years ago ..like how would you guess the maxima and minima before modern measurements ?)

Aug 8, 2016 at 1:18 PM | Registered Commenterstewgreen

Like the new discussion thread (thanks, stewgreen) and especially the title!

Aug 8, 2016 at 12:57 PM Entropic Man
To bowdlerise Macmillan (data, dear boy, data) and Harry Enfield (show me the data)
SimonJ

Aug 8, 2016 at 3:04 PM | Unregistered CommenterSimonJ

Nights are warming faster than days.

Winters are warming faster than Summers.

The further North you go, the faster the warming.

©EM

In a nutshell: The cold bits are warming faster than the hot bits.

Had the converse been true, it would have been quite surprising - and probably contrary to various laws of physics (conservation of energy, etc).

Aug 8, 2016 at 3:34 PM | Registered CommenterMartin A

The theory says that is what to expect and measurements tend to support it. But then UHI has the same effect.

Our problem is the use of such a flawed statistic as global mean temp anomaly as shorthand for the whole complex system of changes.

If we really wanted to know what is going on we would use fewer better records and resist the temptation to swoosh them all in together into a gioant cake mix and bake it first before trying to work out what was happening to the sugar and the butter and the flour.

Take a sample number of stations. Produce time series for each of them. Don't use calendar months or anything non-physical to process them. Compare trends in the individual results. (Then throw away all the land data, that doesn't matter, track the water and ice.)

Aug 8, 2016 at 3:56 PM | Unregistered Commenterrhoda

I think Global Average Temperature is a bit of a fake idea.
But what counts is real physical changes in the local environment. Like over the ages the space where there is/isnot ice, the level or sea, level of rainfall, sunlight (due to varying cloud etc.), dates of Spring/winter DO change and make a difference to the local ecology.

Aug 8, 2016 at 4:06 PM | Registered Commenterstewgreen

stewgreen & others

I have never disputed that the climate changes and always has done, and have no particular argument about EM's statement. I do consider that the methods of measuring the current temperature, and comparing it with those of the past has been a "farce".

A method of assessment of temperature that has never changed depending on language or unit of temperature, is whether or not there was, or was not, a frost, over night.

Cricket Club records may hold information. Kew Gardens and other botanical establishments will, aswell as the big stately homes with their farm records, gardening records and kitchen garden records.

I would be interested to see a simple Yes/No record of frosts in the UK, over the years. From a plant care point of view, the time of the "last frost" is also important. I assume there will be changes to match recent warming AND the hiatus, but what about through the 20th century and the 19th? Or before?

The Central England Temperature -CET, seems to have been the subject of a few adjustments. Frosts records should have some insulation on a yes/no basis, without quibbles over a tenth of a degree or the thickness of the walls of the bucket etc.

Aug 8, 2016 at 6:37 PM | Unregistered Commentergolf charlie

SimonJ

Look at the graphs at GISS here.

Compare the three latitude band graphs. The most northerly band shows the greatest warming rate and the most southerly band the slowest rate of change.

Look at the hemisphere graphs and you see an infection point about 1990 with an increase in warming rate in the north relative to the south.

Look at the seasonal graphs. The is a tendency for the peaks to occur in winter, but the pattern is less obvious than for the latitude comparison.

For diurnal changes, try here.

Aug 8, 2016 at 8:24 PM | Unregistered CommenterEntropic man

I like StevieMac's thought in his latest thread that it is difficult for him to discern either the medieval or the modern warming period in the data of noisy nature. The Holocene has been pretty variable, spatially and temperaturally, not to mention temporally which would be redundant.
===========

Aug 9, 2016 at 9:26 AM | Unregistered Commenterkim

The Qn : What's the Dominant Sub-trend in Temp Rise since LIA ?
@EM That's since the Little Ice Age
...your graphs only cover a tiny portion of that as they only go back to 1880

Aug 9, 2016 at 3:41 PM | Registered Commenterstewgreen

stewgreen, reconstructions of past temperatures are so much easier, if you simply pretend there was no Little Ice Age. This is one of the founding principles of Climate Science, and it's future, along with it's advocates, may hang on it.

Aug 9, 2016 at 5:16 PM | Unregistered Commentergolf charlie

Stewgreen

There are about 70 Holocene proxies and one ensemble, but they won't fit into the BH belief system.

Aug 9, 2016 at 11:10 PM | Unregistered CommenterEntropic man

@SimonJ A pity that no one seriously tried to answer question
I guess you could go over to Judith Curry's blog and find an appropriate post to ask it on.

Aug 15, 2016 at 10:36 PM | Registered Commenterstewgreen