From 90% to 95% confidence level: How IPCC claims can be at the same time consistent and absurd.

We have been expecting too much from the IPCC about its confidence level increase: the explanation may actually be simple… and surprising.

Guest essay by Stephane Rogeau

IPCC_version_confidence

Image: From IPCC FAQs

Many people are wondering what actually made the IPCC raise its confidence level about the fact “human influence has been the dominant cause of the observed warming since the mid-20th century” from 90% to 95%, since its last report in 2007.

Most of the time, it is argued that there has been no warming since 2007 whatsoever, which makes the increase of confidence level in the IPCC’s statement very dubious. But it may be the other way around: because there has been no warming, the IPCC raised its confidence level! And it actually makes sense… at least inside the thought paradigm of the UN organization.

The reason may actually be simple, for one reason: the theoretical warming due to anthropogenic CO2 is, for the IPCC, a given.

It is what makes the climate models “work” (i.e. match more or less historical records). It is actually the basis of the IPCC’s line of reasoning: we cannot find any other way to match our models with the data than by entering feedback assumptions that give climate sensitivity to CO2 the value x… therefore its value has to be around x.

Based on this given assumption that cannot be disproved by facts anymore, and knowing the quantity of CO2 released by human activity, one can easily calculate the theoretical human-induced contribution to global warming since 1951 (let’s call it HIC). Discrepancy with observed global warming (OGW) is, of course, due to natural variability. Therefore, the proportion of human influence in observed warming between 1951 and year “n” is simply p(n) = HIC(n) / OGW(n). If, in year n, the theoretical human-induced contribution since 1951 is for example 0.4°C, and the observed global warming is 0.5°C, then the calculated proportion of human influence is 80%.

Obviously, as we release more and more CO2 into the atmosphere, the human-induced contribution is an increasing function of time: HIC(2012) >HIC(2007). On the other hand, the so-called “hiatus” means OGW(2012) = OGW(2007), as no warming has been observed since 2007. Then it’s just basic arithmetic: p(2012)>p(2007).

Long story short: the proportion of human influence in observed global warming has increased since the last IPCC report because temperatures have leveled off. Translated in terms of confidence level: if the IPCC was 90% certain that human activity was responsible for more than half of the observed warming in 2007, it is not surprising that the confidence level for this same proportion has now risen to 95%.

To conclude: the less warming, the more confident the IPCC about its claims to policy-makers.

Advertisements

  Subscribe  
newest oldest most voted
Notify of
DEEBEE

Cannot discern your sarcasm, but seems IPCC is talking confidence level and you seem to be toying with contribution levels. IPCC contribution fuzzy number is still the weasly greater than 50%

Bravery

And now for my next trick…..

Ken Hall

Not sure that I follow the UN’s confidence according to this article…
… is it suggesting that the more often that they run their flawed models, yet still get the same “fixed” result out of them with regards to their retrospective hindcasting (including using the practice of editing the model after the fact, to retrospectively make it fit what happened before), the more confident they are that the models are still telling them what they need to hear to keep the whole corrupt boondoggle on the road? Regardless of what happens in the actual real climate, their alarmism will ALWAYS be justified?
Is that about it?

Robert Orme

When I studied statistics a long time ago, the 95% confidence level was generally accepted as the lowest figure for useful significance, that is you could repeat an experiment 20 times and 19 of those you would get the same answer, and a 99% level a much better result because of the greater certainty. A 90% level doesn’t mean very much, perhaps there is some relationship, perhaps there isn’t.
On what basis does the IPCC increase its estimates of probability when the temperature has been flat for 17 years whilst levels of Carbon Dioxide have increased by approx 8 %, in other words no significant statistical relationship between these two parameters?

A plain explanation that the Earth receives more radiation during the day than it loses to space during the night or it would long be an ice planet (or near that), would allow the buffer effect of the atmosphere to be called a ‘greenhouse effect’ but the question of whether CO2 has anything to do with it would not be even addressed. That question arises from this original Arrhenius paper http://www.rsc.org/images/Arrhenius1896_tcm18-173546.pdf which is either wrong, or has been cannibalised by the IPCC pseudo-scientists, or has a point which, however, is trivial, if not totally irrelevant in magnitude, compared to all other natural causes and cycles (my current non-scientist opinion). My quantum-electro-dynamics are about equal to absolute zero, therefore I must wait a bit longer until someone explains ‘Arrhenius-right-or-wrong -or-misused’ in simple terms ‘for dummies’ like me.

Flydlbee

Following this technique, if the climate cools, the confidence level will go over 100%.

Mindert Eiting

Confidence level is based on the idea of repeated sampling. What is sampled here from what? Is it possible to obtain 5 percent of samples in which humans are not reponsible for fifty percent of the warming? If you think about this, you may realize the nonsense of the IPCC confidence statements.

Bloke down the pub

Or to put it another way, the threat of agw doing something nasty to us is equal to the warming multiplied by their confidence that it’s all our fault. To maintain the threat level, and therefore their income, as the amount of warming goes down so the IPCC’s confidence has to go up. What happens after it exceeds 100% is as yet undetermined.

jmrsudbury

They should have jumped to 100% confidence then. Zero OGW(2012) is infinity (or divide by zero error). Let’s just stick with infinity. — John M Reynolds

observa

Now if you took a bronze statue of Al Gore and put a thermometer in its mouth and applied a large bunsen burner to its feet Year 12 physics students can all see the time lapse outcome here. Now students you need to repeat the experiment with the real live Goracle and predict the result. We’ll discuss this in climatology class next week.

albertalad

Flydlbee says:
November 21, 2013 at 2:37 am
Following this technique, if the climate cools, the confidence level will go over 100%.
—————————–
Lol – perfect remark. I’m currently @ -30C as I write so this will put the IPCC over the 100% threshold any day now!

MikeB

cleanenergypundit says:
November 21, 2013 at 2:31 am

“The Earth receives more radiation during the day than it loses to space during the night or it would long be an ice planet”

You do realise, I hope, that when it is day on one side of the planet it is night on the other. Even if this wasn’t the case, the amount of radiation that the Earth receives and loses is always in approximate balance (The Radiation Balance). If this was not so the Earth would continuously heat up, or cool down. Energy in must equal energy out!

Brian H

Display edit: p(2012)>p(2007) is used to show p(2012)>p(2007). The ampersand code is unnecessary, and doesn’t work.

Brian H

Oops↑↑ the first > appears as &g t; (no space) in the article text.

William Baird

I think that the answer as to why the models have failed and confidence has grown is simple.
One only has to look at the mindless way politians and others ignore the facts and go around saying ‘look, now confidence that we are acusing global warming has increased to 95%, so it must be right’.
The UN can produce what they like in AR5 (and AR6), it counts for nothing (witness Ban Ki Moons claims that the Philipine storm was caused by man when even the IPCC say otherwise). All that matters is the claim of confidence of 95% – time to act, time to tax, time to re-distribute wealth.
I am confident that AR6 will ‘confirm’ 100% (probably by bringing down the gavel rather than asking anyone), and we will be lead, like lemmings, into the green hell these people desire to see.

Brian H

So is the IPCC’s ploy circular bogosity, or bogus circularity? Hard to tell ….
Mike B;
On the one hand, some solar energy does work on Earth, and hence is not irradiated away (till the final heat death). On the other hand, the core is slowly cooling. I don’t know how those two factors balance against each other, but there is more going on than diurnal heating and cooling of each hemisphere by the sun.

MikeB

Brian H,
Lots of people seem confused that ‘by doing work’ energy is somehow consumed and lost. It isn’t. Energy is always conserved, albeit sometimes in a different form (1st Law of Thermodynamics).
The cooling of the Earth’s core is negligible in comparison to the energy received from the Sun. For example, we receive approximately 340 Watts/sq.m (TOA) from the Sun, geothermal heat is about 0.08 Watt/Sq.Metre (from memory).
If you look up Radiation Balance, you will see that, in the equilibrium state energy-in must balance energy-out.
You are right, however, that in the short term, there may be a slight imbalance due to the points you mention.

Water (H2O) vapor is the earth’s thermostat.

rtj1211

So what happens if we enter a mini-ice age??

Chuck L

I thought the 95% figure of IPCC was pretty much pulled out of the collective a$$’s of a bunch of folks sitting around a table, each of whom said “Sure, 95% sounds OK to me…”

thingadonta

They get more confident over time because of projection and substitution. Projection being what they want to believe is true, and substitution being that what they really mean, is that they think about it not being true only about 5% of the time, whilst they correspondingly assume it is true about 95% of the time, and then they substitute this to mean they are 95% ‘sure’.

Stonyground

I am amused by the graphic. It’s hard to believe that the IPCC produced it themselves when it looks just like the kind of thing that a sceptic would produce in order to take the piss out of them. I mean, gents bog door signs gradually filling up with CAGW certainty, really?

Bruce Cobb

Another way of putting it then would be that they could as well have kept the confidence level the same, but raised the % human contribution to greater than 60% or even greater than 2/3. But, the better confidence trick was to simply raise the confidence level, so that’s what they did. I see now what folks like McKibben mean by “doing the math”. Climate science is so easy, a caveman could do it. In his sleep.

David

You have to go back to the basic ‘raison d’etre’ of the IPCC…
It was set up by the UN to ‘prove’ a link between human CO2 emissions and global warming…
What do you expect them to say..? ‘Nah – no connection. Please send our P45’s (UK end-of-employment document) by return of post..’
Just THINK how many people world-wide would suddenly lose their funding/salaries…!

MikeB says:
November 21, 2013 at 2:54am
“You do realise, I hope, that when it is day on one side of the planet it is night on the other. Even if this wasn’t the case, the amount of radiation that the Earth receives and loses is always in approximate balance (The Radiation Balance)…”
I stand corrected, should be:
“The plain explanation that the Earth receives sufficient radiation on its day side to compensate in approximate balance for its losses on the night side, or it would long be an ice planet if insufficient, would allow ….etc”

UN IPCC Report Exposed By Its Own Members as ‘a pure political process’ — ‘Scientific truth isn’t negotiated in the dead of night behind closed doors’
http://www.climatedepot.com/2013/09/26/un-ipcc-report-exposed-by-its-own-members-as-a-pure-political-process-scientific-truth-isnt-negotiated-in-the-dead-of-night-behind-closed-doors-climate-depot-round-up/

Ah, must be the season to share tortured data.

albertalad says:
November 21, 2013 at 2:48 am
Lol – perfect remark. I’m currently @ -30C as I write so this will put the IPCC over the 100% threshold any day now!

I think you’re enjoying your weather more than anyone should. Must be the season to share torturing data. 🙂
I may be rebreathing some of your CO2 come Sunday….

Jquip

“e cannot find any other way to match our models with the data than by entering feedback assumptions that give climate sensitivity to CO2 the value x…” — OP
In the better part of humanity’s time about the planet, if we didn’t know we had 95% confidence that the cause of it was an anthropogenic spirit. In the more enlightened modern era, the era of the rational and scientific man, if we don’t know then we have 95% confidence that it’s anthropogenic.

Gary

What some call confidence, I perceive as hysterical desperation. Once a learned person leverages their buttocks to a construct, only the strong pill of delusion will suffice once the construct breaks down. And delusion is easy to spot to those outside the delusion.

What new proof that anthropogenic CO2 is causing the atmosphere to rise has been brought forward since 1990 that gives them such an increasing degree of certainty?

JohnWho says:
November 21, 2013 at 5:18 am
What new proof that anthropogenic CO2 is causing the atmosphere to rise has been brought forward since 1990 that gives them such an increasing degree of certainty?
=======
the adjusting of past temperatures to make them colder than what was in the original data is much closer to completion.
people were shorter in the past than now, so when they read thermometers they were looking up, which caused the readings to be too high. Now that people are taller they read the thermometers straight across, making modern readings much more accurate. Thus historical temperatures must be adjusted downwards to be correct.

aaron

Simple, as the rate of warming decreses we can be more confident that half of it is anthropogenic.

Sasha

The IPCC’s confidence level goes up in direct proportion with their desperate demands for more money.

This article has repeated my objections to using such meaningless issues as “is human influenced
warming of a larger magnitude than natural warming.” especially in an unconditional sense.
An answer of yes to the question can be either good or bad, depending upon what’s happening naturally. A significant cooling trend would make one wish for more CO2, not less. Of course, it’s understandable that when the IPCC makes claims in these terms, skeptics reply in those same terms.
And as long as the time span in question is known, one can make claims, although the answer will pertain only to that particular time span. Mostly, this is a concept that only adds to the confusion of the public, who may think there is a single answer for all time frames. Whether humans are the main cause of some warming trend is not of any particular importance. We really want to know two things : how much warming do we get via human influences, in the future, that is? , and what is the natural temperature trend for the future? We cannot, at this point, provide a firm answer for either question.

Stephane

aaron: I think you said it better in one sentence than me in a long article! 🙂

Jquip

@cleanenergypundit: “‘Arrhenius-right-or-wrong -or-misused’ in simple terms ‘for dummies’ like me.”
I’m not terribly certain what you’re asking, but I’ll take a crack at it in a general sense. Is there a buffer? Surely, so; and we don’t need radiative gasses for it. Remember that if we’re not in a quantum radiative mode, then we’re colliding molecules. Or, essentially, atmospheric gasses act as if they’re in a pinball machine. The surface imparts energy to them by kicking them back up the table, where they go collide with anything and everything. But as the atmosphere is largely transparent to incoming radiation, we don’t heat from the top down, but the middle out. So when the sun comes up heats spreads from the surface to below it, and into the atmosphere. But when the sun goes down it necessarily cools from the radiating surface-ish of the atmosphere. So there’s a hysteresis involved in all cases.
CO2, for its part, is something of a sad child. For if we consider that CO2 is hung like christmas tree ornaments — fixed in space at tasteful distances — then there are no kinetics involved. It’s purely radiative. And if you sort out what the radiation has to do to reach equilibrium in a layered model, where each layer has a 50/50 shot of catching any given photon of the right ‘type’ then you find the infamous ‘feedbacks.’ That is, from the surface looking up, you will see your normal black body temperature curve that you’d expect to see given the temperature of the atmosphere. And then a large second peak on the portion under feedback. In no manner is it not a feedback, or proper amplification, in every instance.
Which is exactly the opposite of what we find. Rather than a large second peak in IR, or any other band for a radiative gas, we find a ‘notch.’ That is, there are no feedbacks. No question that the radiation is absorbed, but it is lost by conversion to a perfectly bog standard black body radiation due to collisions. To deal with this, without quantum fuzziness, is the same as what we did to Newton’s child of gravity. Rather than rewrite gravity in a quantum mode, we add a small relativistic correction term and get on our way. It is an epicycle to be certain, but it is also accurate. Likewise, in thermo, we need only add a small corrective to the constituents of the lapse rate equations. Which is to say: It’s works like a non-radiative buffer in every normal manner, if that’s how you wish to consider it. You need only account for the initial absorption of the frequencies of a given ‘type’ being emitted from the surface. Which is also to say that, ignoring convection, heat works in that model just as it does in solid phase matter.
The only significant hazard in this is when you model the Earth as being in global equilibrium. Which is, you take the total energy received on the daylight side of the Earth, and then distribute it evenly across the entire surface. That is, there is no night time. And as we’d quite rather avoid nasty issues of convection, we simply have a habit of pretending that gas is immobile. Both manners provide absolutely absurd temperature increases at the surface. But the knowably wrong radiative feedback model is far less wrong in magnitude, compared to observation, than acknowledging that there are no radiation feedbacks. As that latter goes up exponentially with the number of layers, while the former at a constant fraction.
But then, without convection, or a pulsed input for inrradiance: We’re not actually modelling Earth in any fashion.

Frank K.

Ric Werme says:
November 21, 2013 at 5:00 am
Ah, must be the season to share tortured data.
albertalad says:
November 21, 2013 at 2:48 am
Lol – perfect remark. I’m currently @ -30C as I write so this will put the IPCC over the 100% threshold any day now!
I think you’re enjoying your weather more than anyone should. Must be the season to share torturing data. 🙂
I may be rebreathing some of your CO2 come Sunday….

Yeah, Ric, the forecast here in western New Hampshire is for cold, snow, and wind Sunday (single digit wind chills). There’s a 10K Turkey Trot race on Sunday that I always do – may skip it this year if it’s as cold as they’re forecasting…

RockyRoad

Flydlbee says:
November 21, 2013 at 2:37 am

Following this technique, if the climate cools, the confidence level will go over 100%.

Not only that, but when global temperatures fall off the cliff and we drop into the next Ice Age (which is a certainty), the UN can blame 100% of it on man’s influence.
What?
Man is responsible for Global Warming, AND man is responsible for (Extreme) Global Cooling?
Who knew?
And here I thought the last 30+ Ice Age episodes were sans humanity!!
Now, where do I go to find that initial jawbone?
(I smell a scam–aren’t mathematical limits wonderful?)

Vince Causey

I would like to know where the IPCC get their 95% probability that humans have caused more than half the warming, but this article doesn’t explain it. What it sets out to do is explain how much warming is due to humans, which is a different thing.
IPCC don’t tell us either. They say there is a 95% probability that humans have caused at least half, and one could infer there must be another (lower) probability that humans have caused 2 thirds, and an even lower probability that humans have caused 3 quarters.
It is interesting to observe that the probability increases with each publication though. Shall we have a vote on what AR6 will produce? I’m going for 97.5%, and I am 95% certain of that.

Ed Reid

“Submitted for your consideration:”
1.- The assertion from AR5’s Summary for Policymakers, that it is “extremely likely” (95%+ confidence level) that human activity has caused “more than half” of the global warming since 1950
2.- New study shows half of the global warming in the USA is artificial
Posted on July 29, 2012 by Anthony Watts
PRESS RELEASE – U.S. Temperature trends show a spurious doubling due to NOAA station siting problems and post measurement adjustments.
I think Anthony might have identified the “human activity” which caused the “more than half” of the global warming since 1950.

Jim Rose

Could some one please tell me how many adjustable parameters a typical climate model has. I would like to know effectively how many pieces of information need to be established from hind casting. My motivation is that ill-posed problems (chaotic problems?) are notoriously limited in how much information can actually be recovered from the existing data series.

mkelly

observa says:
November 21, 2013 at 2:48 am
“Now if you took a bronze statue of Al Gore and put a thermometer in its mouth…”
Yup that is where I would stick the darn thermometer. Not.

MikeB

cleanenergypundit says:
November 21, 2013 at 2:31 am
When you ask if Arrhenius was right or wrong, it is not as simple as that. On the whole his work (as given in your link) is meticulous given the limitations of the primitive equipment available at that time.
He is certainly right in knowing that CO2 and water vapour in the atmosphere have a warming effect on the surface of the Earth and he correctly determines the effect of CO2 to be ‘logarithmic’.
He is almost certainly wrong to accept Luigi DeMarchi’s opinion that ‘ice ages’ cannot be caused by celestial events such as orbits, inclinations etc. He thus tries to calculate what changes in CO2 levels would be required to produce glaciation and interglacial periods.
The warming effect of the greenhouse gases is not “trivial or totally irrelevant”. Although Arrhenius rejects previous estimates that the Earth would be at minus 200 degrees C without these gases, a figure of -20 deg.C would be about right.

Daniel

This article operates under the false assumption that the period of 2007-2013 is long enough to reliably discern whether there has been warming. Well, it isn’t – statistical reliability needs a sufficient amount or period of obervations. The increase in certainty however is because this period is added to the existing data which were already showing the warming. It’s statistical basics: increasing the amount of obervations increases the reliability of your results.

Scott

Darth Vader finds you lack of faith in the Forcing disturbing.

Genghis

Jquip says: cleanenergypundit says: MikeB says: Brian H says:
Nah, What the IPCC is saying is that CO2 radiative forcing increases by 1.5 (w/m)^2 every single day for infinity. To put that in perspective that is 550 more (w/m)^2 every year. So in less than a years time CO2 forcing is higher than the Suns forcing.

Vince Causey says:
November 21, 2013 at 6:21 am
It is interesting to observe that the probability increases with each publication though. Shall we have a vote on what AR6 will produce?
==========
next report will be 110% certain, though if they were truly certain they would be 200% certain. 95% certain simply means there is still a possibility that they are wholly and completely wrong.

Jquip

@Jim Rose: “Could some one please tell me how many adjustable parameters a typical climate model has.”
Every climate model uses a global temperature model from some vendor. So they all include temperature as one adjustable parameter. How many more they have after that, I couldn’t say.
@Genghis: “Nah, What the IPCC is saying is that CO2 radiative forcing increases by 1.5 (w/m)^2 every single day for infinity”
True enough. But in global equilibrium each day is infinitely long.

Lars P.

Flydlbee says:
November 21, 2013 at 2:37 am
Following this technique, if the climate cools, the confidence level will go over 100%.
Exactly.
IPCC relies on models, however their climate models do not have the real physics of CO2 effect in the atmosphere inside, but just a “guesstimation” which is wrong.
What is the real physics of CO2? What happens to the net heat transfer in the atmosphere?
1) CO2 has some bandwidth of IR where it is opaque, especially around the main resonance of wavenumber 667. This means that IR radiation in this bandwidth will not travel more then 10-12 meters in the air. If anything happens in this bandwidth between the atmosphere and the soil it happens only in the very first 10-12 meters of the atmosphere. Increasing CO2 concentration shortens the visible path to 9-11 meters etc.
2) There is no such heat transfer by radiation through CO2 in the atmosphere.
Nobody has ever done the calculation of the net heat transfer that would be done between the various CO2 strata in the atmosphere as the numbers are infinitesimally small.
3) Changes in the radiative spectra from the top of the atmosphere to the “universe”. There are some attempts at calculating it and measuring it.
The models replace this with a guessed “forcing” from the top of the atmosphere which was 3.7 W/m2 and was reduced at 3.4 W/m2 for CO2 doubling + the addition of feedbacks which augment the error with the feedback value.
It does not fit the real physical process and so they fail again and again.
This is the reason why they see a hot spot there where it does not exist. This is the reason why they have a warming bias. And adjusting and recalculating the value does not approximate the true physical behavior of the atmosphere.
It works only for the part where warming went in sync with CO2 increase, but they fail miserably in history, all the tries to model climate from animal farts are the nonsense where this line of thoughts leads.

Mike M