In July I wrote a blog post where a strange and very conspicuous step change indeed in global mean temps relative to the trended AMO (North Atlantic SSTa), occurring across the 8-year period of 1963-70, was pointed out:
As you can clearly see, the two curves generally follow each other in remarkable style all the way from 1860 till today, except for the relatively sudden and substantial global upward shift taking place across the last half of the 60s, being firmly established by the end of 1970. After this point, the curves are back to tracking each other to an equally impressive degree as before the shift, only now with the global raised 0.25 degrees above the North Atlantic.
So why this step change? How did it occur?
It coincides neatly with the first appearance of the so-called ‘divergence problem’ in tree-ring proxy reconstruction studies – the tree-rings pointed to significant cooling post 1960, while the official global temps didn’t.
It’s hard to find and defend a plausible natural explanation to the step change. If there were such an explanation, then it has certainly pretty effectively managed to elude everyone within the ‘climate establishment’ for decades. And that’s even in spite of its evidently huge impact on global temps during the period in question. The 60s shift has never been mentioned, much less discussed or investigated scientifically by anyone. Why? Isn’t that a bit weird? Does this mean they don’t know about it? Aren’t they aware of it? No one nowhere within the ‘climate establishment’ has ever put a global temperature graph on top of a North Atlantic (AMO) one and gone “Hmm”?
Have they got no curiosity for how things, processes, might connect in nature?
Or have they simply been so certain all the way from the beginning that the answer to everything climate is already known (a certain trace gas called CO2), that they’ve never felt the need to go look for such possible connections in the first place?
It’s all settled anyway, isn’t it? It was from day one …
Well, the step change is there. It can’t be denied. It’s right there. Whether they feel like bringing it out into the light or not. Whether they feel like letting the public know about it or not.
In ‘Climate ScienceTM’, what seems to be the most important ‘scientific’ term of all, is that thing called ‘radiative forcing’.
‘Climate ScienceTM’ essentially builds its grand story (‘The Great Truth about how the world works’) on the basic premise – one could easily call it its fundamental ‘tenet’ – that the net ‘radiative forcing’ at any one time or time period acting on the Earth system determines (controls, drives) its mean temperature evolution.
This core AGW ‘axiom’ serves as the main input to, lies at the operative heart of all GCMs used to model the Earth’s climate. And they accordingly all provide their results fully bound by its conjecture. Of course, in spectacularly circular fashion.
Look at the bottom curve. It is the total sum of all the ‘radiative forcings’ included and quantified in the upper graph. This black net curve, then, is supposed to depict the ‘Total radiative forcing’ acting on the Earth system from 1850 to about 2002/03.
So how do the models respond to such an input?
They naturally respond by putting out a global (surface) temperature evolution looking like this:
Note, this diagram stretches between 1861 and 2014 rather than 1850 and 2002/03. But you will readily observe still how this blue temperature curve correlates to near perfection with the black forcing curve at the bottom of Figure 1 above. The only real difference appears to be the depth of the volcanic troughs (labelled ‘Stratospheric aerosols’ in the upper graph of Figure 1).
This is what the AGW hypothesis ultimately rests on. This direct connection between net global ‘radiative forcing’ and global mean temperature. According to the AGW hypothesis, the only real mechanism that is able to change the global temperature beyond ‘internal interannual variability’ (i.e. noise), is a change in net ‘radiative forcing’.
In other words, total radiative balance is all that matters. That’s the premise. Determine that and you can determine the temperature. That’s what they believe. And that’s what they claim.
This means that ‘Climate ScienceTM’ basically won’t and can’t acknowledge ocean cycles or any kind of decadal-multidecadal internal variability as a ‘driver of climate’. Their original hypothesis forbids them to.
So they absolutely reject its significance. They need to. Unless, of course, they’re forced to somehow include it, helping them getting out of a tight spot. Like that sticky “Pause” business as of late.
They do it grudgingly, though. Because their real aim, right from the start, was always never having to acknowledge anything as being of any consequence or importance other than their postulated mechanism – the ‘Total radiative forcing’. So they do their utmost and have done so for decades now, working frantically and tirelessly on clearing the path of all unwanted rubble lying in the way of reaching their pre-agreed-upon Truth.
So what do they do in order to get there?
They don’t (and won’t) adjust their basic premise, of course. That would never happen. That would be admitting defeat. So the models are never fundamentally corrected. Since they cannot be fundamentally mistaken. Because they base their output wholly on the core AGW axiom of ‘radiative forcing’ being correct. So adjusting the models would be admitting that there’s something wrong with the axiom. And that would once again be admitting defeat.
No, they adjust reality. The data. To fit it as closely as possible with their model output.
Theory before observation.
So what do you do when you’re in the business of pushing a ‘radiative forcing’ only hypothesis (the AGW one) on the credulous people of the world, when your promotional campaign for an ever growing CO2 impact on global temps is hinging on a secular evolution of global temps following your calculated (and fearsome-looking) ‘Total radiative forcing’ trajectory, and the actual course of progression rather looks something like this?:
Well, you don’t have much of a choice, do you?
You need to do some serious adjusting. Or else people might think your hypothesis isn’t worth shit.
And you need to start early. Way before we reach this stage.
* * *
Before we continue, how was the golden curve in Figure 3 produced? What is the ‘Back-adjusted’ HadCRUt gl all about?
Well, I’ve basically made three changes to the (sadly) officially endorsed HadCRUt4 gl curve:
- I’ve ‘back-adjusted’ the 0.25 degree step change in the global timeseries to realign it with the North Atlantic curve in Animation 1 above, by first detrending its 1963-70 segment and then offsetting its 1970-2014 segment down by 0.25 degrees.
- I’ve also ‘back-adjusted’ the obvious calibration artefact resulting from the Hadley Centre (UKMO) switching SST data sources between 1997 and 1998 and thus producing a never-rectified (and never even mentioned) artificial upward step change in their ocean dataset of 0.09 degrees across the transition. Globally, including both sea and land, this abrupt spurious rise ends up a bit smaller: [0.09*0.71=] 0.064 degrees. You can clearly see the artifical HadSST 1997-98 jump here, compared to three other global SST datasets without a similar switch in data sources:Animation 2.
- I’ve replaced the first part (1861-1943) of the HadCRUt4 gl curve with HadCRUt3 gl. I’ll explain why I did this below. (Calibrating the fit necessitated an upward adjustment of the HC3 curve of 0.04 degrees.)
* * *
What do we notice from the ‘Back-adjusted’ global temperature curve in Figure 3? I’ve singled it out and replotted it here for clarity:
There is still an overall rise in global temperatures over the period, but it is much reduced: The mean rise is now down to about 0.4 degrees from the 1870-80s peak to the 2000s peak. That’s a bit more than 0.3 degrees Celsius per century.
What’s more interesting, though, is that the rise is greatest in the first half of the curve and then levels somewhat off in the second. The 1930-40s peak is clearly closer in elevation to the succeeding peak of the 2000s than to the preceding peak of the 1870-80s.
This would be very hard to explain from an AGW ‘Total radiative forcing’ perspective.
In fact, it would sort of kill the whole idea. The idea, after all, is that the CO2 impact is increasing with time. The pace of the temperature rise thus should and must increase with time also.
So, in order to rescue it, you will have to modify this curve even before it appears. The public can not be made aware of it.
So you start adjusting:
The black curve here, as you can see, is the official HadCRUt4 gl timeseries put together and maintained by the UKMO (UK Met Office, Hadley Centre) and the UEA (Uni. of East Anglia, CRU). The golden curve is the same as the one in Figures 3 and 4, the ‘Back-adjusted’ HadCRUt one.
So you can take in what has been done …
Now you see the discrepancy between HadCRUt4 and 3 in the first half of the graph, from 1861 to 1943. There is basically only two major differences between the two: 1) HadCRU adjusted the temperature down around the time of the volcanic eruption of Krakatoa, moving from version 3 to version 4, and 2) they also adjusted down that ‘1940s blip’ of Climategate fame, going from v3 to v4. (The prominent 1930-40s peak in global temperatures – so inconvenient to the AGW ‘Total radiative forcing’ narrative – had surely been chipped away at even long before the 3-to-4 HadCRU upgrade, but this is at least evidence that they still feel they’re not quite there yet …)
Things really start getting interesting, however, only from the time of the volcanic eruption of Mt. Agung, around 1963-64. This is when the two HadCRUt versions part for real. Watch how the golden ‘Back-adjusted’ curve takes a plunge (as we know, following the AMO) from this point, while the official black HadCRUt4 curve rather seems to dutifully latch on to the path of the assumed/calculated/modelled rise in ‘Total radiative forcing’.
Uncanny, isn’t it?
Then, in 1997/98, the HadCRUt4 curve once more lifts away from the ‘Back-adjusted’ one (harder to spot, but it’s there), trying its best to keep up with the modelled temperatures moving into the 21st Century.
The growing divergence between reported and modelled temps is still seen with the black HadCRUt4 curve – that’s the “Pause” problem right there. Discomforting indeed, but they can still cross their fingers and hope that it will be ‘naturally’ resolved in their favour in the end. Having accomplished their ‘life-saving’ previous (but also still ongoing!) adjustments, there is after all only a ‘problem’ to be dealt with starting somewhen into the new millenium. In reality, the divergence started much, much earlier and the discrepancy today is much, much bigger, represented by the golden ‘Back-adjusted’ HadCRUt curve.
But we, the people, of course never get to see this. The ‘climate revisionists’ took care of it already long ago, even before and as the first official global temperature records were compiled in the 80s and 90s …
So, referring once more to Figure 5, we see where they needed to adjust.
The first half isn’t that important to them. Adjusting this part down is only done so that the present seems warmer, so that the overall warming ends up greater and the temperature rise appears to accelerate.
The 1910-40 rise is perhaps a bit too large, but at least it’s going up, so they don’t want to cut it down too much. The first problem encountered is the 1930-40s peak. It seems all the worse because after it, the temperatures actually drop. Not good. It simply stands out way too much. It points to internal (ocean) cycles rather than a steady increase in ‘Total radiative forcing’.
There are two ways to diminish its visual impact (and without needing to make the preceding decades warmer, of course; that won’t do): 1) cut down the warm peak itself, and 2) lift the succeeding cooling trend. They’ve done both. But mostly they’ve done 2). The (real) drop in global temps from 1940 to 1975 is simply too much to bear. They simply had to get rid of it.
And so they did, GISS even more completely than HadCRU (as can be seen on the ’60s step change’ post).
Global temperature trends are now rather flattish than strongly negative going from the 1930-40s to the late 1970s. It can now be explained away with the negative forcing from post-war industrial aerosols countering the growing positive forcing from increasing CO2.
But then there’s finally relief to be found. Natural warming starts anew. The Pacific Climate Regime (SOI, PDV (PDO)) switches from negative to positive, and the AMO quickly follows suit. This works to the benefit of the warmists. They have done the work, bent the actual global temperature curve so as to link it up with the modelled (‘radiative forcing’-driven) one, so that starting from the latter half of the 70s, all they need to do is lean back and watch the global ocean do the job for them for a few decades.
It all works fine and according to plan up until the point where the temperature plateau of the 2000s starts making itself more and more apparent, becoming more and more of a thorn in the side of the ‘climate establishment’.
The problem for the adjusters this time around, though, is that there are satellites also reporting global temps.
In other words, they can’t just adjust the observed temperatures at will like they did with temps predating the time when the satellites were put into proper operation and started recording. They still do adjust, ever upward, they’re obsessed after all. But there are limits and restraints now. Their estimates can’t stray too far from the satellites’. They can only adjust their temperature records so far before the discrepancy gets too conspicuous and hence too suspicious.
So the tweaking procedure starts taking on a different form, working towards a slightly different end.
What’s interesting is how they basically only adjust post 1994/95 and mainly post 1997. They adjust the 1995 peak following the end of Pinatubo cooling slightly up, then the 1998 El Niño peak significantly down and finally the following temps over the last decade and a half progressively up, especially the late Niña years. All designed to dilute and obscure the originally clear step>plateau progression of global temperatures over the last 40 years, to rather make it look like a steadily and gradually ‘forced’ progression.
Why have they never felt the need to adjust anything between 1970 and 1995? Because during that particular period, global temps did exactly what they were supposed to do. Why ‘improve’ something that works as it should?
The fruits of their labours (thus far), moving on from the closer-to-reality (and – to the “Cause” – severely detrimental) curve in Figure 3 above, can be seen here:
It’s all done with great care, ingenuity and determination. Make no mistake, these people know what they’re doing.
All is to keep the scare going. And the money flowing.
To save face. And positions. Trapped in a lie.