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…”
Prof. Murray Salby in his question and answer section give a brilliant answer to ice related so called atmospheric CO2 trapped in millions of year old ice. Anyone who actually listened to this section would have gotten their answer.
Robert M says:
August 5, 2011 at 9:41 am
That was a riot….. thanks!
Gotta love Emily! This is refreshing! To see some actual work in the field of climate science!
I note that Spencer’s observations on satellite measured heat radiation and Salby’s conjecture reflect very accurately the real world as opposed to the modeled. And both go hand in hand. No wonder Dr. Curry is very interested. I suspect others will react with anger.
Richard,
I’m not saying I’m able to do so. It’s not my thesis, it’s professor’s Salby’s thesis which states the CO2 sensitivity to temperature, not me.
I’m merely stating a counter example that falsifies his proposition. If you now say something like “it’s complicated”, ok sure. I never said otherwise, dr. Salby is the one stating he can recognize this causality and its sensitivity. Please go tell him that he can’t do what he did.
I really don’t get his point. That there is variability in CO2 levels due to natural changes in balance? Why is that news? And, how does that say that human added CO2 does not alter the CO2 balance?
Say, for example, that with no human contributions, CO2 levels fluctuated -1.5 PPM/year to 1.5 PPM/year. Add a human contribution and then they fluctuate from 0 PPM/year to +3 PPM/year. You still have natural variability and still have a human component that is causing increased CO2. This seems to be completely consistent with his presentation.
The only thing interesting and potentially new was that the isotopic concentrations don’t necessarily mean that the extra CO2 in the air is from humans, which doesn’t say it isn’t either.
Don’t get me wrong, I am a skeptic. But, given the larger temperature swings of the past and the smaller CO2 variations that went along with them, I don’t really think that an argument that says that the extra 100 PPM of CO2 is “not from us” holds much weight. In fact, it probably draws away from the truth which is, ‘yes, it is us, but it is no big deal’.
Then again, maybe I was missing something in the presentation because I didn’t have the graphics.
In an e-mail from beyond the grave, Emily Littela admitted to an associate
that she had originally begun to write up her commentary, thinking the topic
was “gerbil worming”.
BTW, if you’ve ever carefully opened a bottle of beer (warm as
traditionalists perfer, or cold as the less refined demand) you might notice
the level of the beverage in the container doesn’t go down as the CO2 slowly
outgasses.
Luis Dias,
Your ‘falsification’ is itself refuted in David Middleton’s links @8:02 am.
My only problem is that…….and correct me if I’m wrong, but, this may be a new study but I thought that knowledge of this was already known. I believe I’ve seen studies on this CO2 lag before.
It may be just me.
Plant stomata clearly indicate high levels of CO2 associated with the Holocene Optimum, Roman Warming and Medieval Warm Period…
Roman Warming and Medieval Warm Period
The CO2 chart is from Kouwenberg, 2004. It is a reconstruction of atmospheric CO2 from plant stomata. It clearly shows that pre-industrial CO2 levels routinely fluctuated from ~280 to 310-360ppmv. The post-800 AD data were also published in Kouwneberg et al., 2005. Dr. Kouwenberg attributed the 400-600 AD CO2 maximum to unspecified local environmental stresses because the high CO2 level could not be matched up with climate warming… She was relying on Mann & Jones, 2003 reconstruction. I used the temperature reconstructions from Moberg et al., 2005 and Ljungqvist 2010; neither of which was available at the time Dr. Kouwneberg published these CO2 reconstructions.
CO2 levels peaked ~230 years after the Medieval Warm Period peaked and the Little Ice Age cooling began and CO2 bottomed out ~230 years after the trough of the Little Ice Age. In a fashion similar to the glacial/interglacial lags in the ice cores, the plant stomata data indicate that CO2 has lagged behind temperature changes by about 230 years over the last millennium. The rise in CO2 that began in 1860 is most likely the result of warming oceans degassing.
While we don’t have a continuous stomata record over the Holocene, it does appear that a lag time was also present in the early Holocene…
<a href =http://i90.photobucket.com/albums/k247/dhm1353/Preboreal.pngPreboreal Oscillation
8200-yr Cooling and Holocene Thermal Maximum
McElwain et al., 2002 also found that a “~77 ppm decrease in atmospheric CO2 at the onset of the Younger Dryas stadial… lagged climatic cooling by ~130 yr.”
The stomata data clearly support a temperature-driven carbon cycle.
The ice cores cannot resolve century-scale or shorter duration CO2 fluctuations. It’s basic Nyquist… “CO2 fluctuation with duration of less than twice the bubble enclosure time cannot be detected in the ice or reconstructed by deconvolution.” (McElwaine et al., 2002 JQS).
The highest resolution Antarctic ice cores have a bubble enclosure time of ~60 years. the Mauna Loa Observatory record is only ~50 years long. It cannot be resolved in ice cores. The century-scale and shorter duration CO2 fluctuations documented in dozens of papers by van Hoof, Wagner, Kouwenberg, McElwaine, etc. from plant stomata do not show up in the ice cores because the ice cores are incapable of recording such short-duration fluctuations.
Smokey,
No, I don’t need ice cores for my analysis. It’s pretty simpler than that.
CO2 was 280 ppm a century ago (more or less). If the sensitivity is, as dr Salby says, of ~100ppm per degree celcius, and if temperature is the main driver of CO2, then how come the CO2 was *only* 280 ppm a century ago, if the temperature is at least 6 degrees higher than the ice ages?
Why, for instance, is the temperature not increasing for the last ten years, and still we see CO2 rising? (wasn’t that fact used against CO2 ->temperature causation here and elsewhere?)
Anyone else scared by this comment
“Dr. Judith Curry has some strong words of support, and of caution:
If Salby’s analysis holds up, this could revolutionize AGW science.”
Note the lack of “debunk” but instead the implied “it will live on as a new form from which we will still demand everything we currently are but for new reasons”…. aka this event will be much like the change from global cooling to global warming… same ppl, demands just a define excuse.
lol – somebody is ready to forsake delusion as a lifestyle? just when they thought the asylum was settled…
a cause ALWAYS precedes the effect. that’s THE fundamental axiom of epistemology.
you can’t even know anything if you get the most basic part of ‘how things are known’ quite backwards.
and yah- what’s with the surprised comments from the liberal arts labcoats? every such instance amounts to a declaration of prior symptoms, eh? confessions, if you will, of gross ineptitude.
it had not been anything scientific – the science was scuttled.
Reply to John Finn August 5, 2011 at 4:50 am
Oceans contain about 93% of all c02, some 50 times more than in the atmosphere
http://tinyurl.com/7uhsuo
Oceans are heating, NOT the atmosphere, though in fact, no-one measures exactly the exchanges in c02 between oceans, air and land.
IE> They are not measured
David Middleton says:
“The stomata data clearly support a temperature-driven carbon cycle.”
___
And no doubt, prior to the onset of human industrialization, the carbon cycle was clearly driven by temperatures (and you could argue, that human industrial activity also is a consequence of the Holocene warmth, so in a round-about way, our release of CO2 continues the relationship between warmth and CO2 levels.)
You seem to be seriously lowering the tone of the discussion here.
1 – You put the word professor in quotes. That means you are emphasizing that word and suggests that you don’t feel that Prof. Salby deserves the title. He has a long list of publications and is clearly respected within his community. Do you have some specific reason to doubt his qualifications?
2 – You have suggested that Prof. Salby should take some classes on diffusion. I listened to the whole podcast and didn’t hear him say anything remotely controversial about diffusion. Did you have anything specific in mind? There have been a number of studies of gas diffusion in an ice column. As far as I can tell, none of them contradicts anything said by Prof. Salby.
Wil says:
August 5, 2011 at 10:37 am
Prof. Murray Salby in his question and answer section give a brilliant answer to ice related so called atmospheric CO2 trapped in millions of year old ice.
____
Since we don’t have any ice core samples of “millions of year old ice” on the planet, it would be interesting to hear his “brilliant” answer.
Not sure if this has been mentioned in later comments, but people in early comments seem not to understand that the outgassing of CO2 from the oceans depends on ocean temperatures, not atmospheric temperature. It doesn’t much matter what the atmospheric temperatures are, except to the degree that they warm the entire ocean, which takes a very long time. So yearly air temperature variations will have very little effect on CO2 outgassing, which proceeds at a slow and steady rate as the oceans warm up, and decline as they cool. Nor will it occur in proportion to changes in atmospheric temperature change.
I’m very amused at how sure you are with the numbers you are using. A six degree C difference with what amount of error? 180ppmv with what amount of error? What were the methods used to come up with these numbers? Your comment seeks to create contradiction where none perhaps exist by demonstrating naught but hubris in supposedly *knowing* exactly what past climate was like. This kind of bold claim of knowledge is not at all surprising from those who believe in CAGW.
Suppose AGW theory is correct and a rise in atmosheric CO2 will lead to an increase in temperature and that this could verry bad effects.
Then why is it a good thing that this is natural?
If it were to anthropgenic CO2 then we would have a chance of of controlling the process. However if this is a natural process and the effects are a natural calamity for us then this would appear to me to be very bad. We would be facing a calamity with no way to ameliorate it.
The souce of CO2 and possible warming due to CO2 increase are separate problems. A natural increase in CO2 would seem to me to be possibly very bad news for us
R. Gates
Since we don’t have any ice core samples of “millions of year old ice” on the planet, it would be interesting to hear his “brilliant” answer.
—————-
Lol! Thanks for pointing out a mere spelling mistake – and might I ask are you reduced to this level of comment? Perhaps you might want to stick the information contained in both the article and those contained in the Q&A section. To do otherwise reduces your level of discourse.
You could also argue that fossil fuels are concentrated solar power… But that’s not relevant either.
The stomata data indicate that atmospheric CO2 would have risen to at least 330-360 ppmv due to the warm up from the Little Ice Age without any anthropogenic assistance. Many, if not most, stomata reconstructions employ quercus (oak) leaves. Quercus stomata are unresponsive to CO2 levels above ~345 ppmv. CO2 levels higher than 345 ppmv will yield the same stomatal index as 345 ppmv.
R Gates
By Physics Today on April 29, 2011 1:08 PM
New Scientist: Four science teams—from Europe, Australia, China, and the US—are racing to retrieve the first million-year-old sample from Antarctica’s ice. Ancient ice could hold clues to past changes in Earth’s climate. Using such ice samples, scientists could study the concentration of carbon dioxide in the ancient atmosphere by analyzing the air trapped in tiny bubbles within the ice. A decline in carbon dioxide concentration could explain the advent of an ice age, for example. One researcher, Robin Bell of the Lamont-Doherty Earth Observatory of Columbia University, and her colleagues have come across a potential problem with the hunt, however. They have found that ice sheets in Dome A, one of the drilling sites, is growing from the bottom up. This could mean that any ancient ice that was once there has melted and been replaced.
———
Here is one example of Prof. Murry Salby “problem” with ice core samples among others he outlines.
Having been through most of a CSU’s physics catalog, I don’t recall any classes devoted to “diffusion physics”. You generally take good core classes, like Mechanics / EM / Thermo / Quantum, and perhaps some blends like Solid State / Particle Physics. I don’t recall any classes that even had sections devoted to this “diffusion physics” topic. I think you’re just making stuff up there.
Also, what “tripe” are you referring to? Most of the information thus far is in an audio-only webcast with no slides, and a single abstract. Do you have access to the paper already? Perhaps you’re part of team defense?
Excellent article, Anthony. Thanks!
I have linked to it from “Climate Change (“Global Warming”?) – The cyclic nature of Earth’s climate”, at http://www.oarval.org/ClimateChange.htm