There is quite a bit of buzz surrounding a talk and pending paper from Prof. Murry Salby the Chair of Climate, of Macquarie University. Aussie Jo Nova has excellent commentary, as has Andrew Bolt in his blog. I’m sure others will weigh in soon.
In a nutshell, the issue is rather simple, yet powerful. Salby is arguing that atmospheric CO2 increase that we observe is a product of temperature increase, and not the other way around, meaning it is a product of natural variation. This goes back to the 800 year lead/lag issue related to the paleo temperature and CO2 graphs Al Gore presented in his movie an An Inconvenient Truth, Jo Nova writes:
Over the last two years he has been looking at C12 and C13 ratios and CO2 levels around the world, and has come to the conclusion that man-made emissions have only a small effect on global CO2 levels. It’s not just that man-made emissions don’t control the climate, they don’t even control global CO2 levels.
Salby is no climatic lightweight, which makes this all the more powerful. He has a strong list of publications here. The abstract for his talk is here and also reprinted below.
PROFESSOR MURRY SALBY
Chair of Climate, Macquarie University
Atmospheric Science, Climate Change and Carbon – Some Facts
Carbon dioxide is emitted by human activities as well as a host of natural processes. The satellite record, in concert with instrumental observations, is now long enough to have collected a population of climate perturbations, wherein the Earth-atmosphere system was disturbed from equilibrium. Introduced naturally, those perturbations reveal that net global emission of CO2 (combined from all sources, human and natural) is controlled by properties of the general circulation – properties internal to the climate system that regulate emission from natural sources. The strong dependence on internal properties indicates that emission of CO2 from natural sources, which accounts for 96 per cent of its overall emission, plays a major role in observed changes of CO2. Independent of human emission, this contribution to atmospheric carbon dioxide is only marginally predictable and not controllable.
Professor Murry Salby holds the Climate Chair at Macquarie University and has had a lengthy career as a world-recognised researcher and academic in the field of Atmospheric Physics. He has held positions at leading research institutions, including the US National Center for Atmospheric Research, Princeton University, and the University of Colorado, with invited professorships at universities in Europe and Asia. At Macquarie University, Professor Salby uses satellite data and supercomputing to explore issues surrounding changes of global climate and climate variability over Australia. Professor Salby is the author of Fundamentals of Atmospheric Physics, and Physics of the Atmosphere and Climate due out in 2011. Professor Salby’s latest research makes a timely and highly-relevant contribution to the current discourse on climate.
Salby’s talk was given in June at the International Union of Geodesy and Geophysic meeting in Melbourne Australia. He indicates that a journal paper is in press, with an expectation of publication a few months out. He also hints that some of the results will be in his book Physics of the Atmosphere and Climate which is supposed to be available Sept 30th.
The podcast for his talk“Global Emission of Carbon Dioxide: The Contribution from Natural Sources” is here (MP3 audio format). The podcast length is an hour, split between his formal presentation ~ 30 minutes, and Q&A for the remaining time.
Andrew Bolt says in his Herald Sun blog:
Salby’s argument is that the usual evidence given for the rise in CO2 being man-made is mistaken. It’s usually taken to be the fact that as carbon dioxide concentrations in the atmosphere increase, the 1 per cent of CO2 that’s the heavier carbon isotope ratio c13 declines in proportion. Plants, which produced our coal and oil, prefer the lighter c12 isotope. Hence, it must be our gasses that caused this relative decline.
But that conclusion holds true only if there are no other sources of c12 increases which are not human caused. Salby says there are – the huge increases in carbon dioxide concentrations caused by such things as spells of warming and El Ninos, which cause concentration levels to increase independently of human emissions. He suggests that its warmth which tends to produce more CO2, rather than vice versa – which, incidentally is the story of the past recoveries from ice ages.
Dr. Judith Curry has some strong words of support, and of caution:
I just finished listening to Murry Salby’s podcast on Climate Change and Carbon. Wow.
If Salby’s analysis holds up, this could revolutionize AGW science. Salby and I were both at the University of Colorado-Boulder in the 1990′s, but I don’t know him well personally. He is the author of a popular introductory graduate text Fundamentals of Atmospheric Physics. He is an excellent lecturer and teacher, which comes across in his podcast. He has the reputation of a thorough and careful researcher. While all this is frustratingly preliminary without publication, slides, etc., it is sufficiently important that we should start talking about these issues. I’ll close with this text from Bolt’s article:
He said he had an “involuntary gag reflex” whenever someone said the “science was settled”.
“Anyone who thinks the science of this complex thing is settled is in Fantasia.”
Dr Roy Spencer has suspected something similar, See Atmospheric CO2 Increases: Could the Ocean, Rather Than Mankind, Be the Reason? plus part 2 Spencer Part2: More CO2 Peculiarities – The C13/C12 Isotope Ratio both guest posts at WUWT in 2008. Both of these are well worth your time to re-read as a primer for what will surely be a (ahem) hotly contested issue.
I’m pretty sure Australian bloggers John Cook at Skeptical Science and Tim Lambert at Deltoid are having conniption fits right about now. And, I’m betting that soon, the usual smears of “denier” will be applied to Dr. Salby by those two clowns, followed by the other usual suspects.
Smears of denial and catcalls aside, if it holds up, it may be the Emily Litella moment for climate science and CO2 – “Never mind…”
Ferdinand Engelbeen,
I can’t find any holes in your logic, but you always stop short of the conclusion: anthropogenic CO2 is not the problem claimed by the alarmist crowd. On balance, the added CO2 appears to be beneficial, not harmful.
Ferdinand:
You assert that the rise in atmospheric CO2 is accumulation of anthropogenic CO2.
If so, then why in some years does almost all the anthropogenic CO2 seem to be sequestered and in other years almost none?
Also, nothing I have presented here is contradicted by a prediction of the late George Beck (who did excellent work collating historic CO2 measurements) whether or not his prediction is correct. We have had enough ‘straw men’ from trolls and I expect better from you.
Richard
Ferdinand Engelbeen says August 6, 2011 at 9:09 am
Well fine, if you want to say the net sensitivity between temperature and CO2 is 8 ppmv/degree-C, that means the effective sensitivity of temperature to CO2 is zero. So why are we undergoing economic agony to reduce CO2, other than to construct a new bureaucracy to administer a new stream of tax revenue?
Getting back to geological physics, there is a lag between cause and effect. If you want to have a model with both a temperature-to-CO2 sensitivity as well as the evident CO2-to-temperature sensitivity, you need to use differential equations, rather than the simple “net sensitivity” you suggest. You can’t back-cast the temperature-CO2 record with a significant sensitivity of temperature to CO2, because you can’t overcome the lag of CO2 behind temperature.
Smokey says:
I can’t find any holes in your logic, but you always stop short of the conclusion: anthropogenic CO2 is not the problem claimed by the alarmist crowd. On balance, the added CO2 appears to be beneficial, not harmful.
True.
But why is no one looking at the cause for the increase in average temps?
They would have to conclude that rising temps were natural and subsequently most of the rise in CO2 as well
(remember at college when we were tasked to remove the CO2 from water to make up a standard solution? How did we do that?)
http://wattsupwiththat.com/2011/08/04/analysing-the-complete-hadcrut-yields-some-surprising-results/#comment-713409
Richard S Courtney says:
August 6, 2011 at 9:43 am
If so, then why in some years does almost all the anthropogenic CO2 seem to be sequestered and in other years almost none?
Because temperature changes have an influence on the CO2 sink speed. That can be seen as a quite good correlation between temperature changes and CO2 increase speed, while the human emissions are quite stable in their increase rate. Temperature changes explain about 2/3rd of the variability in sink rate / increase speed.
But that doesn’t say anything about the cause of the trend itself, as temperature changes largely compensate each other over 2-3 years (with some residual increase/decrease).
kramer says:
August 5, 2011 at 6:05 am
If this is true, then is the ~800 year lag wrong? Or, are we ~800 years behind a previous temperature increase that occurred 800 years ago?
I have a chart that I get to trot out once in a while that might shed some light on this… The CO2 RATE (dCO2/dt) responds INSTANTLY to temperature. The signal is there, the reason you don’t normally see it or hear it talked about is that it’s not easy to de-seasonalize the monthly CO2 data on an exponentially increasing function. But it can be done:
http://naturalclimate.home.comcast.net/~naturalclimate/CO2_growth_vs_Temp.pdf
There is a HUGE amount of information in that chart.
The reason you see a lag is that this instantaneous response must act over a long period of time to produce a large change in atmospheric CO2, because the rate is small. If you look at the raw CO2 monthly data, you can see small changes related to temperature, but they are dwarfed by the seasonal changes and the exponential increase. The 800 year lag you hear about might be interpreted as what happens after a step change, in other words, 5 or 6 time constants = 800 years (you should see 63% of the reaction to a step change in 800/5 or 160 years). But nature doesn’t do step changes, so you’d have to be careful with that. Estimating time constant based on lag is difficult with the ice data because the effect can’t lead the cause, which the data sometimes does. But with the Mauna Loa data, given that the slope of dCO2 is so reactive to the input, I suspect there has to be more than one process involved in the ice data. A fast one and a slow one.
I have my own opinions of what all this means, but I would be very interested to hear what all of you think of it. From this chart, can we conclude anything about:
* The residence time of CO2 before exchange with the ocean?
* What the rate of increase of CO2 would be if the temperature anomaly was zero?
* What does that answer say about what the temperature used to be, if the rates derived in the chart are true? When was it that temperature? Does this match the historical record? Is this possible without an anthropogenic component?
* What can you say about the fact that dCO2 is in an uptrend? Does this point to a natural occurrence? Why or why not?
* If it is natural, does it mean we are in a runaway condition?
I think there is good information there. What do you see? What would you analyze next? I am very interested in your insights on this. Thanks.
Moderator: Sorry, I didn’t close my italics… Please fix?
[Reply: It wasn’t your error, it was a WordPress glitch. That’s how I knew where to close the italics. ~dbs]
Richard S Courtney says:
August 6, 2011 at 9:43 am
Ferdinand:
You assert that the rise in atmospheric CO2 is accumulation of anthropogenic CO2.
If so, then why in some years does almost all the anthropogenic CO2 seem to be sequestered and in other years almost none?
What’s wrong with you, Richard. We’ve gone over this dozens of times. There is a steady rising trend of ~2 ppm per annum (Do you agree with this?) . This would be the annual rise from anthropgenic sources if sea surface temperatures remained constant. However SST does not remain constant. Some years temps are warmer (e.g. during El Nino) and some years temps are cooler (e.g. during La Nina). The transition from La Nina to El Nino, say, can result in an SST increase of 0.5 degrees or more. This can easily explain a 2ppm discrepancy between one year and another. Try de-trending the CO2 data and I’m sure you’d find it matches ENSO pretty closely.
The short term fluctuations in atmospheric CO2 levels would still exist even if humans were not producing emissions. Actully I’m not sure why you would expect a constant increase.
Regarding your other comment (addressed to me) where you claim that the continuing rise in CO2 levels is due to some earlier temperature rise. Could you tell me which temperature rise that might be? Also could you explain how this actually works. That is, could you explain how the atmospheric and sea surface temperatures from an earlier period affects the CO2 exchange between ocean and atmosphere decades later?
Answer these question while also bearing in mind that Professor Salby seems to attribute the large ~3 ppm increase in 1998 to the El Nino of that year.
Re my previous post
Just to satisfy the pedants on this blog: “anthropgenic” should read anthropogenic.
David Falkner says:
August 6, 2011 at 9:08 am
Alternatively, wouldn’t the rate of rise be expected to be much higher now than in 1975 with a much higher proportion of the world burning fossil fuels?
The rise in the atmosphere now is higher than in 1975, but because the increase in the atmosphere is only 50-55% of the emissions (but quite steady!), the change in the curve is less impressive than of the emissions…
The airborne fraction of what humans emitted (in mass, not in original molecules) is remarkable stable, one of the reasons to expect that human emissions are at the base of the increase:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
The 2009 work of Knorr confirms that the rise in the atmosphere still follows the emissions with the same rate as 50 years ago:
http://radioviceonline.com/wp-content/uploads/2009/11/knorr2009_co2_sequestration.pdf
Larry in Texas says:
August 6, 2011 at 2:07 am
R. Gates says:
August 5, 2011 at 8:55 am
Heh, heh, heh. You are toast, buddy. You are toast. You’d best listen to the Selby podcast, instead of making a bunch of nonsensical comments that you are having your hand called on. It destroys your arguments, along with those of your fellow warmists. Don’t be so arrogant to presume that you are more of an authority on the subject than this fellow Selby.
____
I listened to his podcast (twice), and understand clearly what he’s saying. The source of the modern rise (since about 1750 or so) in the NET rise in CO2 in both the atmosphere and oceans is the human use of fossil fuels. Based on Dr. Salby’s own analysis, CO2 should have peaked during the Holocene Optimum and have been falling ever since, and even more so, we should have seen CO2 this high (390 ppm and rising) or higher during the last interglacial period 130,000 years ago, yet we didn’t. But of course, he conveniently rejects the accuracy of the ice core data and only seems to interested in data that support his hypothesis. His complete rejection of ice core data is baffling and disturbing.
For those who’d like to get an accurate perspective on the anthropogenic contribution of CO2 and other GH gases to the atmosphere, might I suggest:
http://www.publish.csiro.au/?act=view_file&file_id=CSIRO_CC_Chapter%202.pdf
R Taylor says:
August 6, 2011 at 10:52 am
Well fine, if you want to say the net sensitivity between temperature and CO2 is 8 ppmv/degree-C, that means the effective sensitivity of temperature to CO2 is zero.
That is true, but the 8 ppmv/degr.C is what is observed, thus that is the brut sensitivity, including any feedback from CO2 on temperature…
But this discussion leeds to far from the original one. For the convinience of Smokey, I repeat here that I don’t expect a huge feedback from CO2 on temperature, and that any such feedback would be largely beneficial…
Question: By how much did the amount of CO2 in the atmosphere increase between 1880 and 2000?
Answer: 640 billion tons
Question: How much CO2 did human beings emit to the atmosphere during the same time period?
Answer: 1620 billion tons.
The difference, about 1000 billion tons of CO2, has been absorbed by oceans and terrestrial vegetation and soils.
Conclusions
1: Human emissions are more than able to account for the rise in atmospheric CO2 .
2. The oceans have been and continue to be a sink of CO2 .
Claims that the increase in atmospheric CO2 has been caused by release of CO2 from the oceans are 1. unnecessary, 2. wrong.
[ Data from the Carbon Dioxide Information Analysis Centre: http://cdiac.ornl.gov/ ]
John Whitman says:
August 6, 2011 at 7:28 am
I have always found your posts to be sincere. Please continue to be sincere by not suggesting you have a scientifically defensive attitude.
Sorry if it can be interpreted that way. I don’t have such an attitude, but of what I have read of Salby is already enough to be careful:
He says that it is impossible to distinguish between emissions from fossil fuel burning and vegetation based on 13C/12C isotope ratios. That is true, but even with a little literature research, he should know that vegetation is a net sink for CO2, not a source at all, thus that problem doesn’t exist.
But if he has good scientific arguments of the opposite, I will change my mind…
Ferdinand Engelbeen says August 6, 2011 at 11:44 am
Thanks for considering my point; I hope I didn’t sound argumentative. It is just so frustrating to see the scientific establishment give Hansen, et al., a free pass on “positive feedback” when their models ignore the obvious sensitivity of CO2 to temperature.
Ferdinand and John Finn:
Ferdinand, you assert,
“Temperature changes explain about 2/3rd of the variability in sink rate / increase speed.”
What!?
The components of the carbon cycle are all unquantified and their behaviours are not known, but you say you know “Temperature changes explain about 2/3rd of the variability in sink rate / increase speed.”
How can anybody know that when nobody knows the possible responses of any of the myriad interacting components of the carbon cycle?
Simply, your assertion is nonsense! The temperature changes could be the cause of all or none of “the variability in sink rate / increase speed”.
And you also assert, “temperature changes largely compensate each other over 2-3 years”.
Really? You know that? How?
Anyway, your claim that such compensation happens is an assertion of magic. Please read my post at August 5, 2011 at 8:37 am .
Ferdinand, we both know that you are better than this. Please ‘raise your game’.
John Finn, my many disagreements with Ferdinand have given me great respect for him over the years. Sadly, your posts addressed to me are not giving me any respect for you.
You ask me;
“What’s wrong with you, Richard. We’ve gone over this dozens of times.”
Yes, we have (see above) and it is clear that what is “wrong” is your inability to read. Since you seem incapable of understanding my words, I quote those of David Wojick on another blog in hope that they may help you to grasp what you find so difficult to understand.
“lolwot and Ferdinand are both confusing arithmetic with causality. The fact that human emissions a numerically greater than the increase in no way shows that they are causing the increase. As Richard points out, a simple reservoir model is a fallacy. This is similar to the simple minded argument that since CO2 is a GHG it must warm when CO2 increases. I call this sort of fallacious argument speculation based on simplified first principles. If there is one thing we have learned about climate it is that it is a complex nonlinear dynamical system.
In particular, the fact that the top levels of the ocean may be increasing in CO2 concentration does not mean that the ocean cannot be the source of the atmospheric increase. Quite the contrary in fact. Remember that the ocean is a biosphere, not simply a reservoir. There are huge CO2 sinks and sources within it, none of which is being monitored or measured.”
I have answered every question you have asked. For example, these;
“Regarding your other comment (addressed to me) where you claim that the continuing rise in CO2 levels is due to some earlier temperature rise. Could you tell me which temperature rise that might be? Also could you explain how this actually works. That is, could you explain how the atmospheric and sea surface temperatures from an earlier period affects the CO2 exchange between ocean and atmosphere decades later?”
Time difference:
See my post to Orson Olson at August 5, 2011 at 5:34 pm
and his reply at August 5, 2011 at 6:47 pm
Mechanism:
See my post at August 5, 2011 at 6:41 am
and my post at August 5, 2011 at 10:07 am
I do not intend to type it out for a third time merely because some troll is trying to be disruptive.
Richard
R. Gates says:
August 6, 2011 at 11:43 am
‘’’’I listened to his podcast (twice), and understand clearly what he’s saying. The source of the modern rise (since about 1750 or so) in the NET rise in CO2 in both the atmosphere and oceans is the human use of fossil fuels. Based on Dr. Salby’s own analysis, CO2 should have peaked during the Holocene Optimum and have been falling ever since, and even more so, we should have seen CO2 this high (390 ppm and rising) or higher during the last interglacial period 130,000 years ago, yet we didn’t. But of course, he conveniently rejects the accuracy of the ice core data and only seems to interested in data that support his hypothesis. His complete rejection of ice core data is baffling and disturbing.’’’’’
—————–
R. Gates,
I have bolded three (3) separate segments of your quote above. You claim he has claimed those three (3) things in his podcast.
Please advise me of the three (3) separate time indexes in the Salby podcast where you find he has claimed each of those three (3) things.
Thank you.
John
Oceans contain some 37,400 billion tons (GT) of c02, land biomass has 2000-3000 GT. The atmosphere contains 720 GT of CO2 and humans contribute only 8 GT
The notion, Ferdinand, of changing ratios because of human activity has a difficult logic Fossil fuels put less carbon-13 into the air, but a tag tells nothing of where it goes (like into the oceans). and oceans can put and take as much c02 from, and into the atmosphere as they would, so oceans regulate how much c02 is in the atmosphere. They can take as much c02 from the air as possible.
If 8.6 GT per year are put into the air, half is said to be absorbed by the oceans, which is 4.3 GT. Yet, we put 4.3 GT p.a into the air around 1970. Why then did not the oceans absorb all 4.3GT p.a produced by humans in 1970. Why were not the oceans absorbing vast amounts of CO2 from the air before humans came along? The obvious answer is that oceans could absorb everything humans produce, but increasing ocean temperatures determine the amount absorbed and are releasing more.
and incidentally, there is no data whatsoever about how much c02 the oceans absorb,release, or exchange, nor is there any data about how much landmass and biology absorb, perspire and exchange p.a. There are models and theories that approximate.
given all this, even if we stopped releasing AC02, it is very unlikely that aerial c02 would decrease, but increase at the same rate, hitherto seen until some time into the future when the temperature of oceans undergo a longterm shift
Is there any data about fumaroles, mud volcanoes, hydrothermal vents, etc and generally all volcanoes, and (including underwater) and how much c02 they put into the atmosphere? Underwater volcanoes are quite a source of ocean heating around Antarctic waters..
Michael D Smith says:
August 6, 2011 at 11:14 am
Whether you intended it or not your graph illustrates exactly what Ferdinand (and me) have been saying. In the context of the last 50 or 100 years THERE IS NO LAG. As you yourself say
The CO2 RATE (dCO2/dt) responds INSTANTLY to temperature.
Note that the “CO2 RATE” is the change in CO2 over a period. This is, in effect, what a graph of CO2 concentration would look like – if there were no human emissions. See Michael’s graph here.
http://naturalclimate.home.comcast.net/~naturalclimate/CO2_growth_vs_Temp.pdf
I suggested de-trending the CO2 data but plotting dCO2 achieves the same result. Now before anyone jumps the gun and suggests that this proves that the CO2 increase is solely a function of temperature – BEWARE! The graph plots dCO2 (i.e the rate of increase) v the actual temperature anomaly – not the CO2 concentration. The actual concentration is a summation of all the increases. I’m beginning to wonder if this is where that Salby guy has got confused.
Let’s try to simplify this:
1. Human emissions are increasing atmospheric CO2 by ~4 ppm per annum.
2. Due to increased sink capacity around 50% of this excess is being absorbed, so that only ~2 ppm remains in the atmosphere
3. However this is just an average figure. The actual amount depends on temperature at the time.
4. If it’s a warm month/year less is absorbed and more released so that more remains in the atmosphere. Vice Versa in a cool year. Michael’s graph illustrates this.
I’d like Richard Courtney to comment on this because I believe he is also in error. I remember, some years ago, having the same discussion on Tamino’s blog – except I was playing the “Salby” role. I couldn’t understand why some of the CO2 increases in the 1970s (e.g. 1977) were larger than some of those in the 1990s (e.g. 1999) when human emissions had increased substantially in the intervening years. Althougn no-one on Tamino’s blog was able to correct me, it did eventually dawn on me what was happening.
John Finn, my many disagreements with Ferdinand have given me great respect for him over the years. Sadly, your posts addressed to me are not giving me any respect for you.
That’s a shame, Richard, but hey-ho, let’s try again
You’ve made a claim that the reason CO2 concentrations rose by 24 ppm between 1998 and 2010 was due to a temperature increase some time prior to this. Presumably this also applies to the 16 ppm increase between 1958 and 1975 (a period of ‘no warming’).
I think your claim is wrong. Michael Smith has posted a graph which shows clearly that the temperature contribution to the CO2 increase is immediate. There is no lag, Richard. You claiming there is a lag or might be a lag doens’t make it so. The data says different. Although Ferdinand might be more polite than me – he is nevertheless saying much the same thing.
If you have any evidence to support the CO2-temperature lag then I’m happy to consider it. However, I don’t mean the 800 year lag that is evident in ice core data. The processes taking place in a continually warming world over the period of ~5000 years is not really relevant to the sudden injection of CO2 since ~1850.
John Finn says:
“If you have any evidence to support the CO2-temperature lag then I’m happy to consider it.”
I’m a little busy right now, but later today I will post charts based on empirical evidence showing that changes in CO2 lag changes in temperature on time scales from months to hundreds of millennia.
I’d be interested to know where you got your numbers. In any event, your arithmetic makes no allowance whatsoever for any source of CO2 other than human beings. An oversight perhaps?
R.Gates says:
http://www.publish.csiro.au/?act=view_file&file_id=CSIRO_CC_Chapter%202.pdf
You have to be kdding me, right?
You are on WUWT so many times and you still have not learned anything?
Try following my blog
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok