From Global Warming Questions -IPCC
How the IPCC invented a new calculus
A new form of calculus has been invented by the authors of the the IPCC’s Fourth Assessment Report (AR4), in order to create the false impression that global warming is accelerating.
How the new IPCC calculus works
Here’s how it works. Look at the following graph:
Now consider the following question:
Is the slope of the graph greatest at the left hand end of the graph, or the right hand end?
By just looking at the graph, or by using old-fashioned calculus developed by Newton and Leibnitz, you might think that the slope of the graph is similar at both ends. But you would be wrong. In fact, the slope is much greater towards the right hand end of the graph. To prove this, we need to apply the new calculus developed by the IPCC. To do this, we draw a sequence of straight-line best fits backwards from the right-hand end-point:
This clearly shows how the slope of the graph is in fact increasing.
How IPCC calculus is used in the IPCC report
Here is one of the key graphs from the AR4 report:
The graph is Figure 1 from FAQ 3.1, to be found on page 253 of the WG1 report. The slope over the last 25 years is significantly greater than that of the last 50 years, which in turn is greater than the slope over 100 years. This ‘proves’ that global warming is accelerating. This grossly misleading calculation does not just appear in chapter 3 of WG1. It also appears in the Summary for Policymakers (SPM):
“The linear warming trend over the last 50 years is nearly twice that for the last 100 years“.
Thus, policymakers who just look at the numbers and don’t stop to think about the different timescales, will be misled into thinking that global warming is accelerating. Of course, we could equally well start near the left hand end of the graph and obtain the opposite conclusion! (Just in case this is not obvious, see here for an example). A similar grossly misleading comparison appears at the very beginning of chapter 3, page 237:
“The rate of warming over the last 50 years is almost double that over the last 100 years (0.13°C ± 0.03°C vs. 0.07°C ± 0.02°C per decade).“
How did this get through the IPCC’s review process?
The IPCC reports are subjected to careful review by scientists. So how did this blatant distortion of the temperature trends get through this rigorous review process? The answer to this question can now be found, because the previous drafts of AR4, and the reviewer comments, can now be seen on-line. (The IPCC was reluctant to release these comments, but was forced to do so after a number of freedom of information requests).
The answer is quite astonishing. The misleading graph was not in either the first or the second draft of the report that were subject to review. It was inserted into the final draft, after all the reviewer comments.
It is not clear who did this, but responsibility must lie with the lead authors of chapter 3, Kevin Trenberth and Phil Jones. Here is the version of the graph that the reviewers saw in the second draft:
Note that in this version there is only one trend line drawn.
So why was this graph replaced by the grossly misleading one? Did any of the reviewers suggest that a new version should be drawn with a sequence of straight lines over different time intervals? No. One reviewer made the following remark:
‘This whole diagram is spurious. There is no justification to draw a “linear trend” through such an irregular record’
… but his comment was rejected.
It is the same story with the misleading comment in the SPM mentioned above (“The linear warming trend over the last 50 years is nearly twice that for the last 100 years“). This statement was not in the original version reviewed by the scientists. It was inserted into the final draft that was only commented on by Governments. The Chinese Government suggested deleting this, pointing out that:
‘These two linear rates should not compare with each other because the time scales are not the same’.
Well done to the Chinese Government for spotting that. Too bad their valid comment was ignored by the IPCC.
h/t to Roger Carr
Many moons ago that wonderful “Journal of Irreproducible Results” published a learned piece on how one set of random numbers could show any desired graphical result by chosing the axes and their units appropriately. Does any reader still have a copy of that article … or even the reference? Been decades since I referred to it and, regretably, my pre-computer-era reference cards have been long consigned to the dust bin of history.
Putting the linear trend over the record is as stupid as putting one on temperature record starting last midnight and ending tomorrow noon. It will be rising, even all noons and midnights are of the same temperature.
IPCC states “warming during last 50 years is probably mostly man-made”, ignoring the warm phases of oceanic oscillations since 1978 whatsoever. Lets wait until they will be both in cold phase like in 1910 or 1965 and then compare again. On the CET record, the 1910 and 1980 cold dips are equal and 2000 warm peak is almost as high as the 1940 one.
I know a “statistical consultant” who uses this practice of fitting straight-lines through time-series. I have one word for such [mal]practice: fraud.
Smokey (17:03:46) : It’s even worse than that: click
Sweet, Smokey! Kinda rounds it off, huh?
David Middleton (14:55:27) :
A very thorough and well written argument. Perhaps this could be promoted to a main article?
At the present time it is 12Celsius. By 2pm it will be 14 Celsius. By the end of this week, based on this trend, our blood will be boiling in our own skulls.
We’re doomed I tell you, doomed!!!
What do you mean that this use of short-term trends is wrong? Tell me where I have told a lie!
Does anyone know of a source where to download the comments for the first and second draft? The harvard page by page view is nerve wreckingly slow and cumbersome to read.
When You see phenomena based discussions degrade to comparing rates of change you know you are witnessing a “beat up”. See the early chapters of Dr Elizabeths Pisani’s “The Wisdom of Whores” for an explanation of the technique and how it was deployed to to induce panic driven action in another global problem area.
Ref – MattN (13:14:32) :
“Worst. “Science.” Ever…”
_______________________
The Complimentary Angle to this expression is…
Best. ‘$cience.’ Ever…”
Dr. Curry commented on this sort of historical editing in her recent interview.
the warmistas are working a new angle 🙂
And we were told that these IPCC reports only contained scientific peer review material not politically modified misinformation.
Out of curiosity, what actual temperature does the Y axis 0.0 equate to? Surely it isn’t 0C, Is it that 14.2C ‘mean’ I see bandied about. The graph doesn’t provide any enlightenment.
Ben Kellet said:
“But……….what if the “misrepresented” trend continues…….what if temps continue to accelerate up the way over the next 25 yrs? Will any of you begin to worry?”
“It is wrong to cheat & to misrepresent but I suspect the intention was to emphasise the point that they believe to be true and which just might be true. Not good science but good for getting non scientific decision makers to see things in ways that they understand. ”
Ahh, the old “But what if…” ploy followed closely by the “well, yeah, it’s wrong, but it’s for your own good” ploy. What you’re saying in the end is that the ends justify the means – a direct lift from the works of Machiavelli and a strategy employed by overlords, despots, tyrants and dictators long before and long after signore Machiavelli graced this fair life. “Damn the truth – the truth is what I want it to be! Now, let’s ram this thing through!”
This is science we’re talking about, not political kabuki theatre. Using false and/or deceptive scientific analysis to sway decision-makers based on one’s hunches, biases and personal paranoia is wrong and most people understand that implicitly. Most people understand and accept that if a position has merit, it has merit because it’s based on credible data, numbers and observations which support the conclusion proffered. Now here come this group of scientists who, for whatever reasons, feel the need to ‘sex up’ their data, numbers and observations to make their point. One can’t help but feel that the need to ‘sex it up’ reflects an inherent weakness in the underlying data, numbers and observations.
“I’m no math expert although I took quite a bit in college. But, to Original Mike, I think all you need to do is look at the early run-up people have mentioned from 1910 to 1940. The slope is greater than the recent one. So what’s to disprove the argument one might make that the 1930s were heating up faster than any known time in recent history and now the warming trend has slowed down.”
Nothing. Nothing at all. Just as you can’t prove the acceleration will continue with this data, you can’t disprove the hypothesis you lay out. I have said twice (and now three times), that their “analysis proves nothing”. It has zero prognostic value. Not having read the relevant IPCC sections, I don’t know if they claim that it does, and if they do their argument is bogus. Having just finished A.W. Montford’s book, and having found the behavior of the hockey team appalling, I wouldn’t be surprised if they did make a case for extrapolation. I was just asking.
“… are your comments serious?”
“I hope you’re joking”
Don’t jump on your friends. I was merely asking a question.
14.2 C is the estimated mean surface temperature of the Earth (right y-axis).
0 C is the global temperature anomaly – GTA (left y-axis).
The GTA is the deviation from some base line period.
These are reference periods of the four major temperature series…
The acceleration of temperature is worse than even I thought. I checked the average high for a six month period (Jan-June 2009) and found it when up by 25 degree F in six months. To see if this could be real I checked the temperature yesterday morning and afternoon (0700&1400) here in the UP of Michigan and it went up almost 30 degrees F in a matter of hours. It sure is accelerating. 😉
Original Mike,
The answer to your question is “yes”… You can use the same “trick” using the data from 1920-1945 and get the same slope as they did using this trick at the end of the “graph”.
You can also pick different starting and ending points and have a best-fit line with a negative slope using fragments of this same data. They are trying to assign some sort of grand meaning to a statistical trick which they used which is essentially meaningless.
mkelly,
That is the funniest, and most apt observation I have seen in a long time!
Denihilist,
Even if you assume that 14.2C was the baseline temp in 1850, and that the atmospheric concentration of CO2 at that point was about 250ppm (which i think is about correct), then an increase in CO2 from 250ppm to 390ppb should have still caused a 2.5C rise in temperature, for a current average temp of around 16.7C.
In REALITY, we are MAYBE (if you believe the thermometers, which is another question entirely) at about 14.7C which is not perceptibly different to ANY LIVING CREATURE from 14.2C. it is certainly nowhere near 16.7C.
So where is this phantom 2C of warming which we should have already had according to the IPCC calculations?
“Well, I understand what they are trying to show, i.e. that the rate of temperature growth has increased more in the later industrial period.
Statistically, this is not an uncommon treatment (breaking up the series and showing the slope for smaller time units). However, to be consistent, they should compare apples to apples & compare the smaller slopes to each other, not only to the overall slope for all data. This will always give a wrong impression. ”
Thanks, Dr. P.H. CRS (15:37:10). This was helpful.
http://www.postimage.org/image.php?v=PqmNabJ
Weeeeeeeeeeeee!!!
I think this deserves an special post:
Mauibrad (13:43:10) :
BETTER THAN #CLIMATEGATE! “Confidential document reveals #Obama’s US climate talk strategy”
http://bit.ly/cCiisZ
Peter B:
I am a scientist of 40+ years, and I see no grounds to even accept the premise that CO2 is increasing. In 1940s (a lag time after the high of the 30s consistent with CO2 being a result, not a cause), CO2 was measured at 400+ ppb at multiple places, using standardized wet chemistry developed by the greatest chemists in the world. At that time they was no vested interest in getting a particular result. Now we use a method that places the sampling next to a VOLCANO and we assume that the monolithic result is accurate, and we accept the results to be a microcosm for the world. I have not yet seen anyone, (even assuming the volcano sampling accurately reflects the world situation), use the standard wet chemical methods developed since the 1800s to try to arrive at an accurate comparison to assess the errors used both in site, sampling, and chromatographic measurement. This would make a great paper, and I assert an hypothesis that today’s methodology introduces large sampling, site, operator, and measurement errors, and this could be found out (could easily be falsified) by an unbiased method. Ahead of that, I am sure, as a prediction, that the actual chromatographic measurement has an excellent (small) coefficient of variance, but the human errors introduced by site, sampling, and operator are large and would swamp this final measurement. It would be tantamount to measuring ones house with a 6 inch ruler, and then reporting the results to 4 decimal places. The current methodology, to my knowledge, does not rule out foul play, since ISO or similar safeguards are to my knowledge not employed, nor are standard methods of scientific auditing used. Did Dilbert (hypothetical grad student hoping for a grant or tenure) breathe into the bag when collecting? Was a low absolute standard used as a comparator? (just have Dilbert leave the standard vial open for a minute). This is not paranoia – this is why ISO and AOAC methods of redundancy of measurement and ascertainment by independent auditors have been developed over the years, to guard against foul play, or introduction of inadvertent systematic error.
PeterB in Indainapolis (08:40:10) :
In 1850, the CO2 level was 290 ppm.
Today, it is about 390 ppm (more like 389.5)
http://www.esrl.noaa.gov/gmd/ccgg/trends/
Fast feedback climate sensitivity is expected to be increase temperature 3 ± 1.5°C for a doubling of CO2 (Charney – using climate models).
Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6°C for doubled CO2 for the range of climate states between glacial conditions and ice-free Antarctica.
http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf
Let’s call it 3°C for a doubling of CO2.
Going from 290 to 390 then would be 1.31°C on this log scale.
What is the measured temperature increase from 1850 ?
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
The record only goes back to 1880.
If 1880 to 1920 is analogous to 1940 to 1980, then 1850 would be at about -0.6°C temperature anomaly. Making the entire 1850 to 2010 temp. anomaly about 1.2°C, or 1.3°C if a new record is set in the next 3 years, as expected.
The important thing about planetary climate change is not that you can put on a coat if it gets 10°C colder – it is that the difference between Ice Ages and hot, humid tropical dinosaur climates all happened within about 10°C swings for the entire planet.
Regional swings, and daily, weekly swings, can be much greater.
http://upload.wikimedia.org/wikipedia/commons/c/c2/Vostok-ice-core-petit.png
http://csccc.fcpp.org/files/f13.jpg