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Discussion > Murry Salby: Relationship Between Greenhouse Gases and Global Temperature

What's the question then, Mr D?

Jul 25, 2013 at 7:52 PM | Unregistered CommenterMissy

Missy

Dung wants my opinion. Which theory do I support? Well the question is the cause of the rise in CO2 and there are two options, the consensus (it's anthropogenic) and Salby. It seems unnecessary to spell it out, but if I must, I favour the consensus.
Jul 23, 2013 at 8:27 PM | Unregistered CommenterMissy

I then asked you which consensus it was that you supported?

Which consensus would it be that you support?
Would it be the one where scientists were asked if man contributed to global warming? If so then most people on this blog would support you (not me). There is no scientific consensus that anthropogenic CO2 is causing the warming because that question was never asked. So Missy, what exactly do you believe?
Jul 23, 2013 at 8:54 PM | Registered CommenterDung

From here on you refer me back to this post

Jul 23, 2013 at 11:40 PM | On there being no consensus, that is silly. There is clearly agreement amongst climate scientists that the rise in atmospheric CO2 has an anthropogenic source Unregistered CommenterMissy

The only actual polls of scientists (however bad) have been very recent and have been based on infantile questions such as the Cook et al poll which asked if scientists believed humans made a significant contribution to warming. You stated that you were not referring to any polls and so I ask again what consensus? Where is your evidence that there is a consensus?
What is fact is that for a couple of decades the media have been stating that it exists, politicians have been stating that it exists and a powerful group of climate scientists have stated that it exists, there is no proof.
It has also been the case that the powerful group of warmists have tried very hard to prevent the publication of scientists who disagreed.

Would you now tell me where the consensus comes from?

Jul 25, 2013 at 8:36 PM | Registered CommenterDung

Mr D, the trouble you go to over the idea of consensus is amusing. You really do belong on the dork side at WUWT.

As a wild guess, I imagine there has never been an opinion poll to test whether people believe that trees are green. Or that ice floats. Or that things fall downward. Does that make these things untrue? It is blindingly obvious that if the rate of increase in CO2 concentrations is half the rate of anthropogenic emissions then the cause of the increases is anthropogenic (sorry Martin, it is). No opinion poll is needed.

Jul 25, 2013 at 9:03 PM | Unregistered CommenterMissy

Missy

Sadly that is the kind of response I expected. Well actually that is wrong; it is he kind of response I hoped for because it reveals just how devoid of knowledge you are.

It is blindingly obvious that if the rate of increase in CO2 concentrations is half the rate of anthropogenic emissions then the cause of the increases is anthropogenic

CO2 started increasing before man started increasing his emissions, that fits with your fag packet science doesn't it? ^.^
Temperature has not risen for 16 years even though we are still increasing CO2 emissions, further fag packet fail.
Salby showed (without any maths and simply using accepted observations including Mauna Loa) that the amount of CO2 in the atmosphere did not vary in step with daily human emissions.
Oh dear I think you should give up smoking.

Jul 25, 2013 at 9:29 PM | Registered CommenterDung

Missy

If it is the case that you do not smoke then you don't have a fag packet to stand on.

Jul 25, 2013 at 9:47 PM | Registered CommenterDung

"CO2 started increasing before man started increasing his emissions..."

I watched Salby again to see where that statement came from. His evidence seems to be that according to Law Dome ice cores, emissions were rising before the instrumental record began the 1957. But our emissions did not start in 1957; the industrial revolution was in the 18thC. The Law Dome record is interesting, showing an almost perfect hockey stick for CO2.

CO2 levels have been relatively stable for hundreds of thousands of years, as some of your fellows here will happily claim. Salby says differtly, but his account is not believable. He plots a curve that shows an exponential rise in the inaccuracy of ice core measurments and claims that 10k years ago the cores are out but a factor of two (in other words 100ppmv in the core was actually 200ppmv in the atmosphere) and 100k years ago they are out by a factor of fifteen (100ppmv was actually 1500ppmv (he says 1000)). He doesn't go any further back for obvious reasons. His graph is exponential remember so at 200k years, levels must be much more than 1000ppmv. And back to 300ka, 400ka etc - the levels must have been huge. Do you really believe that?

And then there is his cross correlation of observed CO2 rises to temperature over the instrumental period. He shows a graph with a peak at a 10 month lag - CO2 lagging temperature and suggests this is significant. But it seems to me that what he is correlating is the wiggles in the graphs, not the slope of the rising CO2. We know that CO2 peaks at the end of spring which is around 10 months after the previous mid-summer, so the correlation is clearly just between the annual northern hemisphere growth cycle and the summer/winter temperature cycle, nothing more. Big deal!

I'm not able to nail any other fallacies in his presentation as it is too complicated. He pulls equations out of the air and I have no idea of their relevance or correctness. (Neither do you you I would guess.) But if even I can spot simple things that seem wrong or insignificant, the chances are that there are more.

So I'd repeat the basic facts that few will reject (ie there's a consensus):

- the rise in atmospheric CO2 has an anthropogenic source

- CO2 is a greenhouse gas

- increasing concentrations of CO2 cause an energy imbalance resulting in energy accumulation.

Jul 26, 2013 at 10:22 PM | Unregistered CommenterMissy

Missy

Now at last you make some good points, two of which are correct; I do not follow his maths and I do not believe the figures you have given for past CO2 if they are indeed Salby's figures then I would say they were totally impossible.
However at least one of your conclusions goes against the facts:

Increasing concentrations of CO2 cause an energy imbalance resulting in energy accumulation.

I am not convinced by the radiation feedback argument so if you would allow I will just deal with "Increasing CO2 concentrations cause warming".

It is universally accepted that the effect of CO2 is logarithmic and therefore that continuously increasing the amount of CO2 in the atmosphere will continuously reduce its effect.
What amazes me is that nobody on either side seems to want to put any figures on this but the ultimate effect is that CO2 has no effect on temperature.
I said nobody on either side but in fact one well qualified poster on Bishop Hill has given a figure with very believable explanation.
AlecM stated that the manufacture of industrial electric furnaces assumes that all the effects of CO2 cease at concentrations higher than 200ppm. The furnaces all work perfectly.
I want to write a long post in the Sense and Sensitivity discussion and I do not want to write it all twice so I will stop there. Maybe you might look there tomorrow night if you are interested.

Jul 27, 2013 at 2:56 PM | Registered CommenterDung

Dung
Have you read the two most recent posts at Climate Audit? Might inform the debate a little.

Jul 27, 2013 at 7:27 PM | Registered CommenterMike Jackson

Missy - an alternative view of what Salby said on diffusion in ice cores...

CO2 levels have been relatively stable for hundreds of thousands of years, as some of your fellows here will happily claim. Salby says differtly, but his account is not believable. He plots a curve that shows an exponential rise in the inaccuracy of ice core measurments and claims that 10k years ago the cores are out but a factor of two (in other words 100ppmv in the core was actually 200ppmv in the atmosphere) and 100k years ago they are out by a factor of fifteen (100ppmv was actually 1500ppmv (he says 1000)). He doesn't go any further back for obvious reasons.

He's not saying the CO2 fluctuations get bigger as you go back. What he is saying is that you have to multiply the ice record figures by bigger and bigger scaling factors as you go back. After you've done this, you find that rates of change and levels of CO2 in recent times are not exceptional.

Let's suppose you had a year when CO2, for some weird reason, was 10 times normal but then returned to normal the following year. You'd then have a thin layer of ice with 10 times normal CO2 in it (eg 4000ppmv). Over the centuries, that layer of ice would "descend" (in reality, be buried under more ice).

The CO2 in the originally thin layer will diffuse into the ice just above and just below the thin layer. So, in 10,000 years, (taking Salby's example) what had been 4000ppmv for one year, will now look roughly like 2000ppmv spread over around two or three years.

Or after 100,000 years, the original layer will have around 1/15th of its original concentration, with the CO2 spread over 10 - 20 layers of the same thickness.

Both rates of change and the sizes of variations measured directly from the ices record are reduced by blurring. The further back you go, the more the record is blurred by diffusion.

I would have thought this would have all been worked out years ago by people analysing ice proxy stuff.

His graph is exponential remember so at 200k years, levels must be much more than 1000ppmv. And back to 300ka, 400ka etc - the levels must have been huge. Do you really believe that?

As I said, I don't think he is saying that at all. He is saying that the variations in the ice record need to be multiplied by a bigger and bigger number as you go further back, because they have been attenuated by greater and greater factors. He's making the point that recent variations are not exceptional - not that ancient variations were colossal.

Jul 27, 2013 at 8:49 PM | Registered CommenterMartin A

Mike Jackson

Yes I had read those articles and now I have also read the article in Quarterly Journal of the Royal Meteorological Society.
Can you tell me what specifically you are drawing my attention to? Many apologies if I am being very dumb here.

Jul 28, 2013 at 12:43 AM | Registered CommenterDung

Martin A,
Yes, that's fairly close to my take on it. It is not necessarily the case that levels were xyz amount higher or lower back in the mists of time, just that the peaks and troughs are smoothed out by mixing/diffusion. You wouldn't expect to see the extreme short-term excursions.

Of course, the same principle applies to many other measurements in the real world.

Jul 28, 2013 at 1:31 AM | Unregistered Commentermichael hart

michael hart: "Of course, the same principle applies to many other measurements in the real world."

Yes, and in the real world, the effects of noise or measurement accuracy severely limit the extent to which blurred signals can be de-blurred to obtain the original.

Essentially on the same theme... After the Met Office published a link to the notorious Marcott paper on its My Climate & Me website with the title “New analysis suggests the Earth is warming at a rate unprecedented for 11,300 years” , I posted the following comment:

Well, I haven’t been able to read the paper, but I wonder if they switched to using instrumental data for the last 150 years? Doing this seems to be accepted practice in climate science. If they *did* splice instrumental data to temperatures estimated from proxies, did they ensure that the temporal resolution was the same before and after the splice?

I assume they did, but if they failed to do so, it would explain why rates of warming (or cooling) similar to recent warming don’t appear before 150 years ago. I understand that temperature data estimated from proxies normally has low temporal resolution, so that rapid changes would simply not be seen.

This illustrates Salby's point - that to compare the instrumental record with the proxy record, the latter needs to be corrected so that you are comparing like with like.

[ The Met Office eventually deleted the article from their website - though not as a result of my comment, I am sure.]

Jul 28, 2013 at 9:02 AM | Registered CommenterMartin A

Well it is quite possible that I misunderstood :-) My comprehension skills seem to be failing me here, for example when you said:

"He's not saying the CO2 fluctuations get bigger as you go back. What he is saying is that you have to multiply the ice record figures by bigger and bigger scaling factors as you go back."

these two sentences seem contradictory. Like saying "he's not saying x, he's saying y", but to me, y is the same as x.

Of your description of a spike being attenuated by diffusion, without any knowledge of the diffusion properties of deep ice cores how can you or I say whether or not this is plausible? Is Salby an expert in the chemistry of ice cores? There are many very clever people who study cores as their day job, surely some qualified and competent people among them, and it seems strange that they would have overlooked this. Maybe Salby knows more about their subject than they do. That doesn't seem likely. Compare this apparent out-of-domain super-sense with his treatment of the correlation between temperature and CO2 over short periods (the 10 month lag) as something significant to his arguments. This seems laughable even to me and I think indicates that he is dabbling in areas of which he has no expertise - he is out of his depth and doesn't realise it.

If there really were such spikes in CO2 then you need a mechanism for producing those spikes. If you are saying it was temperature, then what caused the temperature to spike?

Jul 28, 2013 at 3:09 PM | Unregistered CommenterMissy

Missy - hand-waving discussions tend to be inconclusive. We'd be better off waiting for Salby's stuff to be published and see in detail what he is saying. However...

"He's not saying the CO2 fluctuations get bigger as you go back. What he is saying is that you have to multiply the ice record figures by bigger and bigger scaling factors as you go back."

these two sentences seem contradictory. Like saying "he's not saying x, he's saying y", but to me, y is the same as x.

Please try very carefully re-reading the last paragraph of my Jul 27, 2013 at 8:49 PM posting. I think it should resolve what you see as a contradiction.

Of your description of a spike being attenuated by diffusion, without any knowledge of the diffusion properties of deep ice cores how can you or I say whether or not this is plausible?

Well, diffusion is diffusion, whether it is heat flowing along a metal bar, neutrons diffusing through the moderator of a nuclear reactor or gas molecules diffusing through ice. So understanding the principle is not hard and what he said seems entirely plausible to me. It's a universal effect that diffusion results in things that are initially sharply defined becoming smoothed out and blurred. I don't have any data to try doing a calculation for ice cores but presumably we'll see the details in due course.

I came across a quote in the Journal of Glaciology of 2008: "One common assumption in interpreting ice-core CO2 records is that diffusion in the ice does not affect the concentration profile. However, this assumption remains untested (...)" so it seems pretty clear that ice core experts do not normally consider it.

Is Salby an expert in the chemistry of ice cores? There are many very clever people who study cores as their day job, surely some qualified and competent people among them, and it seems strange that they would have overlooked this. Maybe Salby knows more about their subject than they do. That doesn't seem likely. (...)

Well, diffusion is physics rather than chemistry and Salby is a physicist whose speciality is climate, so it seems quite possible to me that he does know more about that aspect than most ice core experts do.

As I said, hand waving discussions are not going to settle this. When the work is eventually published in detail it will be scrutinised and rejected if it is erroneous, or become standard practice if it is valid:

Jul 28, 2013 at 7:30 PM | Registered CommenterMartin A

Missy,

"Of your description of a spike being attenuated by diffusion, without any knowledge of the diffusion properties of deep ice cores how can you or I say whether or not this is plausible?"

Re-phrasing and re-iterating what Martin A has said, diffusion is diffusion. It is not only plausible, but it is required by the 2nd Law of thermodynamics. The questions are "how much" and "how fast?".

For me, Salby's presentation was certainly lacking in how he arrived at the details of his ice core calculations, but I consider the basis of his assertion as sound. The peaks and troughs of historical data will always be smoothed, and more so the further back you go. Recent data must always be considered with this in mind. I think Marcott (and others) wilfully ignore this aspect.

Some years ago I also presumed that those who made a living in this field had addressed all these issues. These days I am less sure. You can call it physics, or you can call it chemistry. But calling it climate-science does not move it into a higher realm where physicists and chemists gain no admittance.

Jul 28, 2013 at 9:23 PM | Unregistered Commentermichael hart

I've mentioned twice the apparent naivety in his treatment of the correlations in observed CO2/temp and you prefer to totally ignore this in favour of promoting his assumed surfeit of skill relative to his peers. Your faith in Salby is remarkable - but then he is saying what you want to hear.

Now I'm hand waving. Well aren't we all? We are not sufficiently qualified to have an opinion. If you wanted to wait until Salby publishes, then why start the thread?

Diffusion is diffusion? Well it is not without surprises. Consider how graphene membranes can be Helium-tight and yet allow water to pass through. Even if you cannot, I will admit that I don't know enough about diffusion in deep ice cores to comment usefully. Spikes might be attenuated by diffusion and they might not. If they are, then once again, what is your proposed cause for such spikes?

Jul 29, 2013 at 1:41 PM | Unregistered CommenterMissy

The Sun burped.

Jul 29, 2013 at 2:11 PM | Unregistered Commentersplitpin

Missy

My bottom line belief is that we humans are still in the foothills of knowledge about how our climate works. The problem is that the other side claim to understand it well enough to predict it which is total rubbish. Since they continue to make claims, all that is left to us is to pick holes in their evidence. The best solution is for all concerned to admit their relative ignorance and leave this subject alone for a few hundred years.
I for one am not happy to say nothing when our government is embarked on such a stupid energy policy.

Jul 29, 2013 at 3:25 PM | Registered CommenterDung

You lot still arguing with Missy? I'm going to need an extra decimal place to calculate your average IQs at this rate.

Jul 30, 2013 at 3:02 PM | Unregistered CommenterTheBigYinJames

Well we don't care what you compute our average IQ to be. Probably average IQ is more meaningful than average temperature, so go ahead with your calculations.

Jul 30, 2013 at 5:58 PM | Registered CommenterMartin A

BigYin. I wanted to add but got distracted...

We are well aware that Missy is very unlikely to come back and say "OK guys, you convinced me. I have to admit your logic is unassailable". In fact, we are know that she often does not even finish reading our postings before coming up with other reasons why Salby must be wrong.

By the way.... What do you make of the mass balance argument of the SkS folk that the origin of increased atmospheric CO2 has to be due to burning of fossil fuel? They (and Missy) seem to find it utterly convincing whereas, to me, it seems a plausibility argument, rather than a proof.

Jul 30, 2013 at 6:26 PM | Registered CommenterMartin A

Missy -

And then there is his cross correlation of observed CO2 rises to temperature over the instrumental period. He shows a graph with a peak at a 10 month lag - CO2 lagging temperature and suggests this is significant. But it seems to me that what he is correlating is the wiggles in the graphs, not the slope of the rising CO2. We know that CO2 peaks at the end of spring which is around 10 months after the previous mid-summer, so the correlation is clearly just between the annual northern hemisphere growth cycle and the summer/winter temperature cycle, nothing more. Big deal!

I'm not able to nail any other fallacies in his presentation as it is too complicated. (...)
Jul 26, 2013 at 10:22 PM | Unregistered CommenterMissy

I've mentioned twice the apparent naivety in his treatment of the correlations in observed CO2/temp and you prefer to totally ignore this in favour of promoting his assumed surfeit of skill relative to his peers.

I don't know why you describe his computed cross correlation between CO2 and temperature as a 'fallacy' , an exclamation-marked 'big deal', or 'apparent naivety'. He simply computed what it turns out to be from the data. How can doing such a thing possibly be described as 'apparent naivety'?

You have given an explanation for why it has that form but I don't see that that invalidates anything he said.

It is absolutely normal for cross-correlation functions to be computed from only the wiggles in the time series - mean values or trends/slopes have to be removed first if you want to get something meaningful.

He explained how the same thing would show up from the proxy record - it would be a simple spike, if the proxy record's temporal resolution were limited so that only details coarser than 1500 years could be seen. To me, it seems perfectly reasonable to give such an example in a discussion of the relation between the atmospheric and proxy records.

Jul 30, 2013 at 11:16 PM | Registered CommenterMartin A

Martin,

Sorry, you miss my point. Missy is not here to be convinced by argument, she's not even here to read your replies to her unending questions. She's here to waste your time, and as a sideshow, to demonstrate how gullible deniers are in being led up the garden path. She's being fed questions and responses by someone very well informed on the consensus position - it wouldn't surprise me if somewhere there is a private blog where your and Dung's responses are being measured, recorded and laughed at by a group of people - perhaps even as another Lew-esque psychology experiment. Expect the paper "The Unending Gullibility of Deniers" soon.

You seem to think she wants us to prove how 'scientifically knowledgeable' we are. She doesn't. She want's to see how long she can spin out a pointless thread for, because there's more than one way to be stupid, and they have noticed we beat them on the science every time.

I don't even think Missy is a 'she' as such. I suspect the name was chosen carefully to elicit certain male responses from the denier demographic. Perhaps if this person was called GrumpyBloke or say BitBucket, that you probably would not be wasting so much time on it. This is perhaps a side experiment. Compare an contrast the length of threads when the nick is male or female.

She's not here to be convinced by your arguments, she's here to demonstrate how foolish deniers are. Please don't prove her correct.

Jul 31, 2013 at 8:44 AM | Unregistered CommenterTheBigYinJames

Well, I admit that I had assumed Missy was someone at SkS's old lady.

"You seem to think she wants us to prove how 'scientifically knowledgeable' we are." I do?

I was finding it interesting to observe how her responses would degenerate - the last being "well it seems obvious to me he's talking rubbish on correlation so he must be talking rubbish on other things too".

Jul 31, 2013 at 9:19 AM | Registered CommenterMartin A

Martin, it is not the cross correlation that is fallacious, but its use. He wants to show that CO2 rises _after_ temperature rises (that it follows the integral of temperature) and his correlation result purports to show just that. If he were just doing an interesting side-exercise in comparing annual plant growth and CO2 cycles, he would have surely have said so instead of giving the impression that the 10 month lag strengthens his theory. He uses that correlation plot more than once I think, which is odd for a graph showing that summer is warmer than winter and plants grow in the spring.

James, you are a cynic. I thought we were having a nice discussion, not an argument. However it would indeed be interesting research project to study how many conflicting ideas some of those here can hold at the same time. I have seen it written that this is a right-wing phenomenon, so it would be interesting to find whether left wing blogs have the same characteristics. The discussion here is not perhaps very useful, as you say, especially as, taken together, people demonstrate that they are happy to rely on arguments supplied by others with which they disagree if it helps the group as a whole score 'points'. Pretty point-less really.

I am not controlled by others as you think, but you are right that there are some colleagues with whom I have discussed our conversation. They actually think I am nutty talking to you. Come September I shall be too busy to play here so you'll be rid of me. You'll no doubt be happier just talking among yourselves.

Jul 31, 2013 at 1:30 PM | Unregistered CommenterMissy