Correlation of Net CO2 emissions with climate properties shows that the growth in CO2 may be natural
Story submitted by WUWT reader Steve Brown
The narrative of the catastrophic anthropogenic global warming has been challenged at many levels but this presentation by Professor Murry Salby, Chair of Climate at Macquarie University rips up the very foundations of the story.
The talk (in the video below) was given at the Sydney Institute 2nd Aug 2011
He elegantly shows that there is a solid correlation between natural climate factors (global temperature and soil moisture content) and the net gain (or loss) in global atmospheric content when the latter is averaged over a two year period. The hanging question remains, if natural factors drive more than 90% of the growth in CO2 how significant is the contribution of human generated emissions. The answer is simple… not very.
The talk has been covered in the past on Judith Curry’s blog, and an abstract of the talk is here . But this is the first time I have encountered a video of the talk or been able to see the slides which he referenced.
Fascinating.
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Thanks for the links guys.
Half-way through wathing the video … Salby appears not to be aware of the tens of thousands of direct measurements of atmospheric CO2 prior to 1960.
Has Beck’s work in historical analysis of previous, direct measurements of atmospheric CO2 already been buried so deeply?
There was much discussion of this on Climate, Etc. last fall, and this winter some asked if the promised paper had been killed or rejected. I wrote Salby, and got this reponse on Feb. 20:
Sorry Bart, but simple maths is exactly what is needed here. The statement 4>2 is all that is required.
http://wattsupwiththat.com/2008/12/17/the-co2-temperature-link/#comments
Allan M R MacRae (01:13:19) :
For previous work on this subject, please see
MacRae (January 2008)
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
I
am still pondering my conclusions in my paper – as some critics have noted, there are two drivers of CO2 – the humanmade component and the natural component, and both can be having a significant effect – critics suggest the humanmade component is dominant. If Earth cools significantly, perhaps we’ll see.
Following my email to him, Roy Spencer also wrote on this subject at
http://wattsupwiththat.com/2008/01/25/double-whammy-friday-roy-spencer-on-how-oceans-are-driving-co2/
One more reference on this subject is by climate statistician William Briggs, at
http://wmbriggs.com/blog/2008/04/21/co2-and-temperature-which-predicts-which/
Prior work, which I became aware of after writing my 2008 paper, includes:
Pieter Tans (Dec 2007)
http://esrl.noaa.gov/gmd/co2conference/agenda.html
Tans noted the [dCO2/dt : Temperature] relationship but did not comment on the ~9 month lag of CO2.
Keeling et al (1995)
http://www.nature.com/nature/journal/v375/n6533/abs/375666a0.html
Nature 375, 666 – 670 (22 June 1995); doi:10.1038/375666a0
Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980
C. D. Keeling*, T. P. Whorf*, M. Wahlen* & J. van der Plichtt†
*Scripps Institution of Oceanography, La Jolla, California 92093-0220, USA
†Center for Isotopic Research, University of Groningen, 9747 AG Groningen, The Netherlands
OBSERVATIONS of atmospheric CO2 concentrations at Mauna Loa, Hawaii, and at the South Pole over the past four decades show an approximate proportionality between the rising atmospheric concentrations and industrial CO2 emissions1. This proportionality, which is most apparent during the first 20 years of the records, was disturbed in the 1980s by a disproportionately high rate of rise of atmospheric CO2, followed after 1988 by a pronounced slowing down of the growth rate. To probe the causes of these changes, we examine here the changes expected from the variations in the rates of industrial CO2 emissions over this time2, and also from influences of climate such as El Niño events. We use the13C/12C ratio of atmospheric CO2 to distinguish the effects of interannual variations in biospheric and oceanic sources and sinks of carbon. We propose that the recent disproportionate rise and fall in CO2 growth rate were caused mainly by interannual variations in global air temperature (which altered both the terrestrial biospheric and the oceanic carbon sinks), and possibly also by precipitation. We suggest that the anomalous climate-induced rise in CO2 was partially masked by a slowing down in the growth rate of fossil-fuel combustion, and that the latter then exaggerated the subsequent climate-induced fall.
Kuo et al (1990)
http://www.nature.com/nature/journal/v343/n6260/abs/343709a0.html
Nature 343, 709 – 714 (22 February 1990); doi:10.1038/343709a0
Coherence established between atmospheric carbon dioxide and global temperature
Cynthia Kuo, Craig Lindberg & David J. Thomson
Mathematical Sciences Research Center, AT&T Bell Labs, Murray Hill, New Jersey 07974, USA
The hypothesis that the increase in atmospheric carbon dioxide is related to observable changes in the climate is tested using modern methods of time-series analysis. The results confirm that average global temperature is increasing, and that temperature and atmospheric carbon dioxide are significantly correlated over the past thirty years. Changes in carbon dioxide content lag those in temperature by five months.
Regards, Allan
jimmi_the_dalek says:
April 19, 2012 at 7:25 pm
Sorry, Jimmi, but that’s just stupid. Read the posts at the link I gave.
I saw this video a few weeks ago, and didn’t find it too impressive. As stated in other posts, he shows that there natural perturbations which affect the year to year additions of CO2 to the atmosphere. If you plot the year to year changes in CO2 from the Mauna Loa data, you will see that there is an upward trend in them. Take this plot and add how many ppm CO2 man has been adding and you’ll see that this line accounts for the upward trend. I’ll link where you can find the data you need below. If you subtract the amount of CO2 that humans are adding to the atmosphere you end up with a relatively flat curve whose natural oscillations basically add up to zero (about 8ppm).
This argument is pointless to have anyways, as we know the following to be true.
1) We know that we are adding CO2 to the atmosphere. To claim otherwise is to deny reality.
2) We know that adding CO2 to the atmosphere will cause some change in temperature (the magnitude of this effect is in question).
Here are the links to the data you need if you want to make the graphs I mentioned:
http://www.esrl.noaa.gov/gmd/ccgg/trends/
http://cdiac.ornl.gov/trends/emis/tre_glob.html
One note on making the plot, I used a went with the assumption that 50% of our CO2 is adsorbed into natural sinks. If you use 40%, you will find that the natural variation would have a total impact of about-4.6ppm.
Colin says:
April 19, 2012 at 8:00 pm
It is a fact that the accumulated human emissions curve is basically a trend with some slight positive curvature. It is also a fact that measurements of atmospheric concentration reveal essentially a trend with some slight positive curvature. Beyond that, what can you say?
Is it a major coincidence that you can take two trends with slightly positive curvature and make them look similar to one another through scaling and biasing? No, it is not. Simply do a least squares fit to an affine function, with the one as the dependent variable and the other as the output variable, and you will find the bias and scale factor which makes the one look most like the other in a least squares sense.
The argument is not pointless, but I will agree that it is not the one which will drive a stake through the heart of AGW. Unless and until the two time series start to diverge substantially in morphology, the superficial resemblance will be enough to convince most people that there is a cause and effect relationship.
Thylacine says
April 19, 2012 at 2:35 pm
The AGW folks seem to want to suck and blow at the same time when it comes to oceans and CO2. I don’t think one has to be a board-certified climate scientist to assess the merits of that conjecture, does one?
—————-
Good point in contrasting the decrease in ocean CO2 since the ice age with current concerns about increasing CO2 leading to ocean pH increases.
I think it comes down to the numbers. I’ll have a go even though I have no clue.
CO2 during the ice age was about 250ppm.
After things warmed up it was 350ppm.
So this means there was100ppm equivalent dissolved in the ocean.
It was pushed into the oceans by the low temps.
Currently we are above 450ppm.
If we reduced our consumption so that it stayed at 450ppm, eventually the ocean would absorb 100ppm worth of CO2, in effect returning ocean CO2 to its ice age value..
It is being pushed into the oceans by high atmospheric concentration.
This might be OK if we could ignore temperature. I am not sure we can, since pH and a whole lot of chemical and biological processes have a strong dependency on temps.
The notion that we can keep the value at 450ppm depends on us producing CO2 at the same rate as the ocean absorbs it. Except we are not doing that, we are doing it faster. Therefore it seems likely that we will eventually push more CO2 into the oceans than was present during the ice age. Hence ocean pH rises will happen. How much will depend on how much CO2 we put into the air and any countervailing temperature rise.
There is deep time evidence that this can happen, high temps, high CO2 and low pH. A lot of things died.
Steve Brown says
The hanging question remains, if natural factors drive more than 90% of the growth in CO2 how significant is the contribution of human generated emissions. The answer is simple… not very.
—————–
So we have this strangely persistent belief that bank accounts can’t possibly work.
So how many climate skeptics also subscribe to the bank account skepticism principle?
1. We have a bank account with1000 dollars in it.
2. Each payday we put in 200 and over the week spend 200. Result no change in the balance.
3. So we want to get ahead and find a part time job. Say 20 per week extra.
4. We spend an extra 10 and save the other half, 10.
So here is the test.
How many of you think that after 100 weeks you will now have 2000 in the bank?
How many of you will reason that 10 is so small it makes no difference? You will still have just 1000 in the bank?
The answer should expose a few dumbasses.
Jimmi_the_dalek says:
“Sorry Bart, but simple maths is exactly what is needed here. The statement 4>2 is all that is required.”
If I remember the mass flux argument correctly, you start out with a soil dam that is partly full of water. Over a given set period of time, say one month, there are natural losses (e.g. by soil absorption or by evaporation) and gains (e.g. by inflow from the surrounding soil or by water being added to the dam by rainfall and runoff) of water to the dam. These losses and gains either produce a net inflow or a net outflow of water from the dam, with the water level changing accordingly.
The analog of what is observed in the real world.
Someone, adds a small amount of “anthropomorphic” water over the month, half of which is lost (e.g. by soil absorption or by evaporation), and half of which is retained in the dam. The observer notices that at the end of the month, the water level in the dam increases slightly.
The question now becomes, “What type of underlying natural losses and gains must be taking place during that month to produced the observed result when “anthropomorphic” water is added to the dam?
Clearly, If a NET NATURAL GAIN of water to the dam is assumed, then an observed water level rise that is less than that expected by the NET “ANTHROPOMORPHIC” ADDITION of water to the dam, would rule out a NET NATURAL GAIN of water from the dam.
I think that the problem for the Salby model is that the observed rise in CO2 p.p.m.in the atmosphere is less than the NET ADDITION of “anthropomorphic” CO2 in p.p.m. This means that according to the water mass flux dam model, there can be NO NET NATURAL GAIN of CO2 by tthe atmosphere (e.g. by emission of CO2 from the oceans).
Of course, this model assumes that ALL of the natural CO2 has the same sources and sinks
as the “anthropomorphic” CO2, and that all of these sources and sinks were absorbing/emitting both types of CO2 at the same rates. This is the Achilles Heel of this argument.
What I have never seen satisfactorily explained is why the carbon sink today is greater than it was 5 years ago, which in turn was greater than it was 10 years ago, which in turn was greater than it was 15 years ago etc.
I am aware that increases in biomass has something to do with it, but that is to some extent off-set by lower ocean capacity due to increase in ocean temps.
The point I am getting at is: had the capacity of today’s carbon sink been available say 30 years ago, there would in fact have been little, if any, rise in CO2 in the atmosphere. Understanding why that capacity was not available is important.
The carbon cycle and understanding the workings of all carbon sinks needs much more work and attention.
Philip Bradley wrote:
“If short term factors explain the CO2 changes, there is nothing to explain in the longer term. There is no methodological flaw. It is that simple.”
No, it’s not. Different processes respond on different time scales. The year-to-year variations in the atmospheric CO2 mole ratio have a magnitude of about 3 ppm, compared to the long-term increase of CO2 from 280 ppm from pre-industrial to 394 ppm today. You can’t simply presume that the processes that dominate small magnitude short-term fluctuations also govern long-term changes with the same weight, which have a magnitude the multiple of the short-term fluctuations.
So, if you claim a 0.8 increase in the globally averaged temperature causes an increase in the CO2 atmospheric mole ratio by 114 ppm, where is the Medieval Warm Period in the CO2-record from ice cores then, which many here believe had globally averaged higher temperatures than present day?
http://cdiac.ornl.gov/trends/co2/graphics/lawdome.gif
And don’t many here claim “global warming has stopped” since 1998? Why is the CO2 mole ratio still increasing year to year, if it was controled by the temperature by such a large degree, then, and if it was true what you say, that when you have explained the short-term fluctuations you have explained the longer-term change?
Also, what was the CO2 mole ratio in the atmosphere during the glacials, when it was 3 to 4 Kelvin colder on global average than today, if a 0.8 K temperature change causes a change of the CO2 ratio of 114 ppm?
“What I have never seen satisfactorily explained is why the carbon sink today is greater than it was 5 years ago, which in turn was greater than it was 10 years ago, which in turn was greater than it was 15 years ago etc.
I am aware that increases in biomass has something to do with it, but that is to some extent off-set by lower ocean capacity due to increase in ocean temps.”
That’s where the error is – the ocean capacity is not lower, because although it is slightly warmer, which means the solubility of CO2 at a constant pressure would be slightly less, the partial pressure of CO2 in the atmosphere has actually increased by nearly 40%. The solubility is directly proportional to the pressure (Henry’s Law) so the oceans are absorbing CO2, not releasing it.
LazyTeenager says:
April 19, 2012 at 8:46 pm
Ah, but the bank, seeing you have more money to give away, hires more middle managers and starts charging fees to pay them. So that $10 a week becomes a $20 deficit, and by 100 weeks you’ve gotten an overdraft warning.
Hold on a second. The temperature dependence is real, yes, and is a yearly phenomenon, but on multi decadal scales you all know it doesn’t line up.
http://i.imgur.com/0CgHN.png
We put +8Gt up every year, but only +4Gt change is seen in the air at the end of each year. Arithmetic says +4.0 – +8.0 net effect of nature on atmosphere is negative. Nature is presently a net sink of CO2 from the atmosphere, no other conclusion is compatible with observations.
http://imgur.com/z2pma
That’s based on numbers used by Dr Tom Quirk (a well known climate skeptic), which he gathered from different sources.
To disagree, you must show either the calculated atmospheric carbon content increase is too low by a factor of 3 or more (good luck showing that), or else the reported anthropogenic carbon release is too high by a factor of 2 (good luck showing that’s wrong based on fossil fuel sales).
Can we stop this “nature is the main source of the rising CO2” nonsense, you are just making us skeptics look bad. Either show the observed numbers are fraudulent, or shut up.
jimmi_the_dalek says:
April 19, 2012 at 9:34 pm
That’s where the error is – the ocean capacity is not lower, because although it is slightly warmer, which means the solubility of CO2 at a constant pressure would be slightly less, the partial pressure of CO2 in the atmosphere has actually increased by nearly 40%. The solubility is directly proportional to the pressure (Henry’s Law) so the oceans are absorbing CO2, not releasing it.
So getting back to my question: If oceans are absorbing CO2 from the atmosphere now that temps are rising, why were they releasing it (at an 800 year lag) when temps were rising historically (according to the ice cores)? I still do not see how you can have increasing ocean acidification due to net absorption of CO2 at the same time as net outgassing of CO2 due to temperature increases. If the outgassing of CO2 is not correct, then how do the AGW folks account for the lag in the ice core records?
My previous comment has been devoured by the blog for no discernable reason (according to my understanding of your policy page), so please dig it out of the filter bin.
[REPLY: Stuff often finds its way to the spam filter and may take a bit of time to get out. Your patience is appreciated. -REP]
“So getting back to my question: If oceans are absorbing CO2 from the atmosphere now that temps are rising, why were they releasing it (at an 800 year lag) when temps were rising historically (according to the ice cores)? I still do not see how you can have increasing ocean acidification due to net absorption of CO2 at the same time as net outgassing of CO2 due to temperature increases. If the outgassing of CO2 is not correct, then how do the AGW folks account for the lag in the ice core records? ”
I’m not a climate scientist, so no comment on the lag, but the basic point is that the solubility of CO2 depends more on the pressure than on the temperature, and the partial pressure of CO2 was different then.
“although it is slightly warmer, which means the solubility of CO2 at a constant pressure would be slightly less, the partial pressure of CO2 in the atmosphere has actually increased by nearly 40%. The solubility is directly proportional to the pressure (Henry’s Law) so the oceans are absorbing CO2, not releasing it.”
It doesn’t necessarily follow that the increase in CO2 in the air is enough to offset or overcome the effects of a change in ocean surface temperatures on absorption capability.
Water being so much denser than air the effect of warmer or colder ocean surfaces will be far, far larger than even a 40% change in the concentration of a very minor trace gas.
If jimmi_the_dalek says otherwise would he please produce empirical evidence.
“We put +8Gt up every year, but only +4Gt change is seen in the air at the end of each year. Arithmetic says +4.0 – +8.0 net effect of nature on atmosphere is negative. Nature is presently a net sink of CO2 from the atmosphere, no other conclusion is compatible with observations.”
That is not evidence that nature is a net sink.
The ocean surfaces have been warming since the LIA so throughout that period of time the capacity of the oceans to hold CO2 has been falling naturally.
It is more likely that ever since the LIA nature has been a net source of CO2 when the warming oceans are taken into account.
Nature itself could be producing the extra 4Gt with the human contribution negligible after it has been taken up by local or regional sinks such as nearby vegetation.
“where is the Medieval Warm Period in the CO2-record from ice cores then, which many here believe had globally averaged higher temperatures than present day?”
It would appear that the ice core record is too coarse to reproduce the atmospheric CO2 changes during the 1000 year cycle from MWP to LIA to date.
Or possibly the ice core records are not an accurate enough record of atmospheric CO2 due to the time taken for the CO2 to become sealed in the ice column. It is likely that during the sealing process which can take place over many seasons the CO2 quantities in the ice/water gradually depletes as the water repeatedly cools and warms over successive seasons until eventually it becomes permanently frozen.
The absence of a clear MWP/LIA/Current Warm Period signal in the ice cores is not conclusive evidence either way.
The possibility of the ice cores being an inadequate reflection of CO2 amounts in the air is also supported by the observation that the old chemical methods of measurement gave higher readings than those produced by the ice cores.
You can’t simply presume that the processes that dominate small magnitude short-term fluctuations also govern long-term changes with the same weight, which have a magnitude the multiple of the short-term fluctuations.
Explain to me how long-term fluctuations are more or less than the sum of the short term fluctuations for the short time periods that comprise the long-term period.
Until you can do that, I am afraid you have no argument.
“Water being so much denser than air the effect of warmer or colder ocean surfaces will be far, far larger than even a 40% change in the concentration of a very minor trace gas.
If jimmi_the_dalek says otherwise would he please produce empirical evidence.”
Look up the phrases “partial pressure” and “Henry’s Law”, then come back when you have learned that the solubility depends on the partial pressure and that the density of water is irrelevant.
Professor Salby shows that man’s emissions are not the cause of the increase in atmospheric CO2 concentration. Further, he demonstrates that CO2 rise follows temperature. Our entire energy policy in this country is based upon the opposite of this and Al Gore and his acolytes still dominate the media coverage of weather and climate.
Why has there been no wider coverage of this comprehensive debunking of the whole AGW theory?
Any ideas?