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
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.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
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%
And now for my next trick…..
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?
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.
Following this technique, if the climate cools, the confidence level will go over 100%.
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.
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.
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
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.
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 @ur momisugly -30C as I write so this will put the IPCC over the 100% threshold any day now!
cleanenergypundit says:
November 21, 2013 at 2:31 am
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!
Display edit: p(2012)>p(2007) is used to show p(2012)>p(2007). The ampersand code is unnecessary, and doesn’t work.
Oops↑↑ the first > appears as &g t; (no space) in the article text.
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.
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.
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.
So what happens if we enter a mini-ice age??
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…”
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’.
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?
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.
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”