and spare me the appeals to authorities of whom nobody has heard....Salby?

The simple explanation that CO2 is the control knob of the climate is perfect for simple minds.

It is interesting that a climate kook like diogenes is dismissing the ice core data. In the run up to the climate social mania the ice core was part of the gold standard showing how modern temperatures were dangerously rising and showed doom was nigh, etc. diogenes seems to implicitly be moving away from actually dealing with the facts and grasping more desperately to the frothy hysterics at root of their faith.
As the hiatus continues, and the weather extremes predicted fail to appear, even the fanatic kooks seem to realize that reality is not their friend.

Dung, all facts are theories. There are no facts.

Dung,

As to the thing about facts v theories, it's a false dichotomy you're setting up. All scientific facts are theories at different stages of evidential weight (there are roughly 5 of them, or perhaps 4 and a half!)

1. Implausible - a theory is contradicted by one or more other more established theories which would need to be overturned to allow this one to prosper. This stage is sometimes called scientifically 'impossible' by the media. Perpetual motion machines fall into this category.

2. Possible - a theory is not impossible in that it doesn't contradict other theories, but there is no evidence that it is true. Speculative theories fall under this category, such as 'life on earth came from a comet' - it is possible, but there is no reason to suggest it is actually true.

3. Plausible - a theory is possible and has a little empirical evidence it is true. Plausible theories tend to be expressed as a relationship between things without a description of the mechanism. 'mouthwash causes cancer' is a good example. A lot of epidemiological and statistical studies fall into this category.

4. Probable - a theory has lots of supporting evidence, and is held as the de facto 'fact' about some phenomenon until a better theory comes along. A lot of medicine falls into this category - descriptions of processes that were once thought of as the best way to describe something are overturned by a new idea or discovery.

5. (or 4.5) Highly Probable - a theory has so much supporting evidence that to overturn it would be to overturn many other highly probable facts. But it could happen. Most of basic physics (perhaps excluding QED, which is more a 4) falls into this category. The basic 'laws' of physics and chemistry fall into this category. This is what the lay person would call a 'fact'

So when you say some people prefer theories to facts, what you are really saying is 'people prefer theories that have less evidence'.

Ice cores as a proxy for temperature fall between 3 and 4 for me. Yes, it is possible and plausible that they can be used this way, but there is some doubt about the mechanism that gives any such reconstruction wide error bars. They can be used as supporting evidence along with better measurements, but they are not good enough on their own.

This highlights my main problem with the way millennial temperature reconstructions are done. All the evidence is patchy - most fall into the plausible category. On their own they are not good enough to move the 'theory' up a notch. Climate science has lots of these 'low quality' evidential lines - ice cores, pine cones, tree rings, coral, plankton etc. and they argue that the quantity of them can overcome the quality issues, which is a mistake in my opinion. Low quality evidence does not strengthen each other - in the same ways as 10 gang members saying they weren't at the scene of a crime does not strengthen the case over 1 of them saying it.

Now as Diogenes says - extra greenhouse gas WILL mean more heat energy into the system. This is a scientific theory which falls into the 4 to 5 category. Arguing against it is like arguing against gravity or electricity. This is why we get annoyed and dismayed when we keep seeing people arguing against the GHE or the heat trapping properties of greenhouse gasses.

Extra heat into the system DOES NOT MEAN that the temperature goes up, or we get more storms, or that there's any sort of catastrophe. These are outputs of a complex stochastic auto-correlated system with multiple sinks, into which heat energy is one input. The idea that a few ergs into the mix at one end gives a smooth linear rise in one or more of the outputs is stupid, weak and indefensible. It falls only into the possible and maybe plausible category of the speculative theory. This is what we should be attacking, not the basic physics underneath. We look stupid when we argue against category 5 'scientific facts' when there are so many '2s and 3s' around hiding in the bushes that underpin the whole of alarmism.

As a side note, some on this side fall into the same trap when they claim that 18 years of CO2 rise with no warming disproves the idea that it might happen - it actually argues against our own thesis that the system is auto correlated with long feedbacks. All it proves is there is no immediate linear relationship - which we (on this side) and climate scientists themselves already knew, but which the simplistic media and greenies don't. It neither proves nor disproves the idea that there is some non-linear time-delayed effect. 18 years is not long enough to disprove the link (just like 30 years of correlation was not enough to prove the link in the up direction), but it's getting there.

tl;dr, I know.

As to the other stuff, worry ye not, been extremely busy here at my IT company (business is booming, shouldn't complain) and nothing much has been happening in the climate world - I have been lurking.

The greenhouse effect magnitude would be modified by additional atmospheric CO2 if that was to cause a reduction in the speed of solar energy passing through this planet. Currently it isn't. There is no evidence that it ever did.

ssat,

By saying "we have no evidence that extra CO2 causes a reduction in the speed of solar energy passing through the system" is the same thing as saying "the magnitude of the change in GHE is uncertain", which I think we all agree on, even most of climate science. That's not really what Dung was arguing.

Since CO2 causes (in part) the GHE, more CO2 *might* (and arguably *should*) increase this effect, but since it's a complex system, the effect may also be mitigated by some other factors (saturation, compensatory feedbacks, etc.) - leading to a smaller value for climate sensitivity than the linear relationship that alarmists peddle would give. The sceptic case is that there is only a weak or non-linear relationship between CO2 concentration and climate sensitivity - not that there is NO relationship (as some here would prefer).

Arguing it can have no effect is silly, basic physics tells us it can and should. Our case is to argue not that it CANNOT, which is futile, but that it DOESN'T, because of compensatory feedbacks and sinks that climate models do not current consider well.

Dung, it's incredibly difficult to measure the GHE. The fact that we can't do it easily, and historically haven't been measuring it over the timescales required to show the change does not mean there is no change. We've spoken at length about the tiny signal in a very noisy set of measurements, and how difficult it would be to measure it empirically. Again, the fact that we can't or haven't isn't the same thing as saying there is no evidence, which implies people have been measuring but can't find it.

You can't measure the density at the surface of the sun either, doesn't mean it doesn't exist.

Lack of measurement is not the same thing as lack of evidence.

Well, it's a fair point. There are many things in science which we can't measure, but we 'know' they exist because they are logical conclusions of other things we DO know exist, and are fairly sure of (on the 1-5 scale I gave earlier, scientific theories which fall into the range 4-5)

We know how CO2 behaves as a way to trap heat energy in a mixed gas. This is a no-brainer, high-school physics exercise, it's as close to a scientific fact as you can get. Therefore the logical extension to that is that we should assume it behaves the same way in the atmosphere UNLESS you can show a reason why it SHOULD NOT.

Now, I agree this is dodgy ground for empirical physics. You're inferring truth by reasons of finding no contradiction. In my opinion, any theory found by extending other secure theories but depending on the fact that you can't imagine anything to contradict it makes it a theory of lesser quality.

So CO2's heat trapping behaviour in a laboratory = 5 on the scientific fact scale. (Highly Probable)
And CO2's heat trapping behaviour in a model atmosphere = 4, because something unknown might stop it. (Probable)
CO2's ability to trap heat in a real atmosphere = 3-4 because many other poorly understood factors at play (Possible)
CO2's heat trapping to be amplified by feedbacks = 2-3 only plausible because very little evidence (Plausible)

So what I'm really saying is that your doubt should be spread over these 4 levels of CO2's impact, with very little doubt on the first one, growing to a lot of doubt on the last one. Trying to reduce the complexity of this argument to a binary decision about "fact v theory" or "theory v observation" misses the nuances of what is being proposed and the logical chain of the assumptions of alarmism.

Alarmists think all 4 of these are Highly Probable, and will argue on that basis. 'Deniers' think all four of these are Highly Improbable and will argue on that basis. Both positions are equally stupid. The evidence supports neither position. Each side uses the extreme of the other ("deniers denying basic physics" v "alarmists believing speculative unproven theories") as a way to continue the argument.
.
The truth is that the amount of doubt should be spread from almost zero to a lot over the 4 propositions. That is the only logical way to approach this.

"your new improved friendly neighbourhood" TheBigYinJames

Dung

Firstly, science does not do proof. "Highly probable" is as good as you get, because there is always the possibility that the next experiment will show that you are wrong.

If you want 100% certainty, talk to a mathematician, a politician or a priest.

Secondly, there is an experiment that shows how CO2 traps heat. Take a long tube with end windows transparent to infra-red radiation. Fit an IR source shining 15 micrometre IR into one end(call it A)and fit IR detectors at both ends.

As a control, fill the tube with a non-greenhouse gas such as nitrogen. Shine IR into the tube at end A and it will all emerge from the other end B. Very little IR will be redirected back to A.

Gradually add CO2 to the gas mixture.Some of the IR will be absorbed by CO2 and reradiated in all directions. Now most of the IR will emerge at B, but a small amount will be directed back to A.

As you increase CO2 concentration the proportion of IR absorbed and reradiated increases, less IR reaches B and more is redirected back to A. The amount emerging at B will decrease from 100% towards 50% and the amount emerging from A will increase from 0 towards 50%.

When there is enough CO2 all the IR shone into the tube is absorbed and reradiates in all directions. It has saturated. 50% of the IR emerges at A and 50% at B.

Note that ,strictly speaking, CO2 does not trap heat. It traps IR. The trapped heat appears when the redirected IR is absorbed by the surface and raises its temperature above what you would measure without CO2.

EM,
Please advise your dear pals in climate kook land that they should quit with the "discussion is settled" blither.
Thanks,
etc.

Well, what a thread. Dung being friendly, Entropic Man supporting one of my posts... perhaps being confrontational isn't always as useful as it is fun...

Dung, as EM said in support of my 'Highly Probable' fact about the absorption properties of CO2, there is a high school experiment which shows CO2 behaves in this way in a laboratory. We have no reason to suppose that CO2 in the real atmosphere doesn't behave in the same way - in general. What we aren't sure about is what else is happening in the atmosphere which also affects heat content. Such things might include saturation of the effect, cooling feedbacks from other sources (albedo, wind, sinks, etc) This is where true scepticism lies, not in questioning the well-understood 'fact' of CO2 absorption and re-emission.

Mike, I agree with your dissatisfaction with 'Greenhouse' 'Heat Trapping' etc etc. but we're stuck with them as terms of reference.

Thumbin theairy.

Some model runs did predict the hiatus.

Yeah. I’ll bet they all hooted 18 years ago when that wavy line popped out.
“No, don’t chuck it. It’s got a lovely uptick for the year 2100.”

Some model runs did predict the hiatus.

None of them did, in advance.
This is because nature does not move in smooth straight lines. Only simplistic models do.

Since the models were trained to match historical data, it's no surprise that by tweaking them they can
get some of them to match the hiatus, but only after the event. I used to work in mathematical modelling
(of networks, not atmospheres, but similarly complex) and it's incredibly easy to do post-mortem curve-fit
with a model with sufficient control knobs. As Feynman said, with four parameters I can fit an elephant,
and with five I can make him wiggle his trunk.

Now when a climate model manages to model some unforeseen dip or spike ... in advance of it happening...
then I may sit up and take note of climate models. Until then I watch the thermometers for my predictions.