Dung
My belief is, and Chandra for one thinks I'm mad in thinking this, that as the the earth has seen more extreme conditions in any 'direction' than we're now experiencing then the climate isn't actually changing merely moving within normal limits. The green house gas theory is plausible but the effects don't seem to be measurable at the moment. Therefore CO2 cannot be considered a major player with the information we have currently.

You may well be correct in what you say and the maximum CO2 warming has been passed, seems like an equally plausible theory to me.

Archaeological evidence suggests that the planet has experienced warmer more benign conditions than today during the current inter-glacial, which I think adds weight to your

It is not happening Bob

I too would be interested in a tearing apart of the ideas rather than the messenger.

May 10, 2014 at 7:16 PM | Dung
Pass

I'd say what I'd say to a warmist, come back to me in twenty years when there's more data to prove it either way.

I don't think anyone is saying that temperature doesn't go up and down irrespective of CO2 (except those who only saw Al's movie). Warmists shot themselves in the foot by sweeping that under the carpet. They now have nowhere to go but backwards, since they ruled periods of no warming out in the early stages. How much of the 80s and 90s warming was down to natural and how much was CO2 is a question I don't think can be answered yet. For all I know, strong man made warming is being cancelled out by strong natural/man made cooling. I just don't see much evidence for it.

Why the insistence the question must be answered? When you polarise the issue you do what the warmists do - all or nothing. People don't always jump into the camp you want them to.

Dung
I do not know the answer to your question

Please explain why the evidence from the ice cores is not considered to be cast iron evidence that CO2 does not always cause global temperatures to rise?

hence my earlier post. To me it seems pretty cut and dried that historically it is difficult to make a connection. But if someone is convinced that CO2 is the only cause in all cases then there is nothing anyone can say or do to convince them otherwise, possibly subconsciously biasing research workers, after all current post graduated researchers have been taught CO2 is the sole cause of warming/climate change for their entire lives.

As Martin A says apart from That above a certain level, co2 has no further effect I'm not clear what else is being attacked?

To my reading most postings here are neutral to supportive.

"Please explain why the evidence from the ice cores is not considered to be cast iron evidence that CO2 does not always cause global temperatures to rise?"

I'll try.

The oft-repeated sceptic argument is that because CO2 rise lags behind temperature rise, then it cannot have caused it. This is very a powerful argument where the rate curves appear simple (most people enjoy straight lines, I guess). Of course things rarely are straight lines, and more complex rate equations can certainly show many surprisingly-shaped curves to the unwary.

The 'consensus' reply usually runs thus

"Yes, that is true initially where the first bit of temperature rise [caused by something else not detected or measured in the ice-core data] causes, maybe, an initial increase in CO2. This causes not much effect initially due to ocean-overturning causing some sort of a delay due to thermal and/or chemical buffering. Then, after this lag phase, the CO2 warming really gets into its stride and thereafter the further temp rise is due mainly, if not all, due to CO2."

I think that sounds like a theoretically plausible explanation.

But it also violates Ockham's (Occam's) Razor in that it invokes a more complex explanation than the simple one which is that "Temperature mainly drives CO2". If both explanations fit the data, then Ockham says you take the simple explanation. For the consensus argument to prevail, it must produce some extra data which contradicts the equally, or more, plausible simple explanation. [And also, what is the "something else"?]

What might such data look like? I've not seen it discussed.

Well, with shockingly minimal detail, here's a different, but hopefully helpful example with some one-graph data:
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Look at figure 10.6 on page 7 (page 369 of the original) of this pdf file.

In chemistry texts this is a classical teaching example for non-linear kinetics in the enzymatic hydrolysis of nitrophenyl acetate. The plausible/accepted mechanism derives from a close and detailed look at the course of the reaction over time.

Of the several different reaction products [think of them as processes or events if that helps], one, ES, (pink line) initially appears as a burst. It then gradually declines. The "main"product, P, [the one usually measured] appears very slowly at first but then increases to a faster rate. You can see that the line of P doesn't extrapolate back to the origin linearly at the beginning of the experiment. [Other components do different things but not all are shown].
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I'll simplify further, hopefully not too much.
The key point is that most of the shaded pink part of the graph labelled "steady state", and beyond, is NOT the most important part of the experiment. The most important part of the graph is the little bit at the left hand side soon after the beginning of the experiment. It's a "watch the pea" situation.

Look at where the lines all cross over each other near the beginning. If the scientist/student wasn't looking/measuring carefully or quickly enough, and thus the data was not well enough resolved on the time axis then this data would be unavailable and the plausible, detailed, explanation of the mechanism would not be supported. What's more, it may never have been proposed in the first place either, but climate science often appears to do things 'differently'.

Returning to the 'consensus' explanation, it appears, IMHO, that the ice core data simply does not contain sufficiently detailed data to support an appropriate kinetic analysis. In papers such as Skakun 2012 (Nature) the detail just isn't there in the proxies and the uncertainties swamp everything. So how can the more complex explanation prevail? And what, exactly, would we expect to see?

I don't know. But I haven't yet even seen a proposal, anywhere, from anyone who supports the consensus explanation. I haven't seen any discussion either of any relative changes in the continuing slopes of the CO2/temperature plots during temperature rises. In the CO2 ice-core record, it seems like another case of "watch the pea" where nobody from either side much cares. [And I think it is also incumbent on proposers to put forward a detailed explanation of what happens when temperature and CO2 start to fall.]

Until then, I'm sticking with Ockham's Razor. [This is way too long now, so:]
The consensus explanation (of the ice core record) appears similar to "The Deep Ocean Ate My Heat" in that there is a conspicuous lack of data to justify choosing it over a simpler explanation.

michael hart
I like your explanation, it is reasonably concise and very clear. The Ockham's Razor/Deep Ocean Ate The Heat logic is difficult to argue against.

Apropos of nothing important but I was struck by your graph and that the line P looks to be asymptotic it bit like Dung's CO2 and warming effect eventually reaching a maximum.

Dung, can't help you I'm afraid, certainly CO2 absorbs and emits radiation in the 4 and 15 micron ranges, but the only correlation we have between CO2 and temperature is in the 1990s. Given that there, there is no correlation in the paleoclimate records, there was an increase in temperature between 1910 and 1940 with no significant increase in CO2 and a stasis in temperature between 1998 and today with an 8% increase in CO2 you would think, wouldn't you? that someone in the clisci community would take a step back and consider the dogmatic propounding of CO2 as the earth's temperature control knob.

I believe there at two things mitigating against what would be a natural step in any other science, re-looking at the hypothesis, these are: Money. This scare has attracted massive amounts of money into climate science, and no one can be expected to back away from such largesse; the second is embarassment, not just for climate scientists, but for the whole scientific community, who've thrown their weight behind a theory that "citizen scientists" have disparaged, and apparently, will subsequently prove to be correct.

Given the all too observable pomposity and self-regard of the scientific establishment we're not going to see any backing away, or humility from them, which gives me the opportunity to answer Martin A's question about when and how will it all end. When the pompous self-regarding people at the top of the scientific establishment can find an escape route that will save their pompous and self-regarding asses, or when they've all passed on.

MartinA, I'm also looking forward to the second attempted launch of the orbiting carbon observatory in July. I hope the data gets freely, transparently, and competently distributed.

Having discounted models that have been falsified by nature, and Trenberth's nonsensical physics, if we are searching for any empirical evidence of increasing CO2 concentrations changing temperatures it seems sensible to examine the differences between the arid equatorial deserts and the humid tropics (where we may assume that H2O is the dominant "greenhouse gas"), and how they have changed in recent decades.

If CO2 is a powerful "greenhouse gas" then the diurnal temperatures of the Sahara should have become more like those of Singapore - but they haven't. Conclusion - an increase of order 20% in atmospheric CO2 concentration has had a negligible effect on the diurnal surface temperatures of the planet.

Roger, I have long wondered what explanation they have for the delta in desert temperature (CO2 and no water) and the tropics (CO2 and lots of water) where I need fans during the night because the temperature drops by only a few degrees. Additionally in the tropics the temperature during the day only rises by the small amount it fell during the night, hinting that the clouds are the temperature knob if we really have one, because in the desert (no clouds) the temperature delta can be 30C.

Additional information today from Martin A that there's more CO2 above the Amazon and sub-tropical Africa means that they shouldn't get hotter during the day if the CO2 is the control knob, but as in the tropics the delta is a few degrees C.

The problem seems to be that this is empirical data, not suitable for the models, because it doesn't fit the paradigm.

I do wonder what the explanation could be though, it seems unlikely that a whole scientific body hasn't noticed this and come up with a reason.

Geronimo, if I remember correctly it was you that first raised the "desert anomaly" at BH?

After ploughing through all of the flawed physics, and modelling nonsense, it was this that finally convinced me of the absurdity of CAGW, coupled with the fact that the climate has been shown to be both significantly warmer, and cooler, in the historical data of the last millennium.

I think that you answered your own question: "... it seems unlikely that a whole scientific body hasn't noticed this and come up with a reason" with: "this is empirical data, not suitable for the models, because it doesn't fit the paradigm".