NOTE: Earlier today I posted a paper from Joe D’Aleo on how he has found strong correlations between the oceans multidecadal oscillations, PDO and AMO, and surface temperature, followed by finding no strong correlation between CO2 and surface temperatures. See that article here:
Warming Trend: PDO And Solar Correlate Better Than CO2
Now within hours of that, Roy Spencer of the National Space Science and Technology Center at University of Alabama, Huntsville, sends me and others this paper where he postulates that the ocean may be the main driver of CO2.
In the flurry of emails that followed, Joe D’Aleo provided this graph of CO2 variations correlated by El Nino/La Nina /Volcanic event years which is relevant to the discussion. Additionally for my laymen readers, a graph of CO2 solubility in water versus temperature is also relevant and both are shown below:
Click for full size images
Additionally, I’d like to point out that former California State Climatologist Jim Goodridge posted a short essay on this blog, Atmospheric Carbon Dioxide Variation, that postulated something similar.
UPDATE: This from Roy on Monday 1/28/08 see new post on C12 to C13 ratio here
I want to (1) clarify the major point of my post, and (2) report some new (C13/C12 isotope) results:
1. The interannual relationship between SST and dCO2/dt is more than enough to explain the long term increase in CO2 since 1958. I’m not claiming that ALL of the Mauna Loa increase is all natural…some of it HAS to be anthropogenic…. but this evidence suggests that SST-related effects could be a big part of the CO2 increase.
2. NEW RESULTS: I’ve been analyzing the C13/C12 ratio data from Mauna Loa. Just as others have found, the decrease in that ratio with time (over the 1990-2005 period anyway) is almost exactly what is expected from the depleted C13 source of fossil fuels. But guess what? If you detrend the data, then the annual cycle and interannual variability shows the EXACT SAME SIGNATURE. So, how can decreasing C13/C12 ratio be the signal of HUMAN emissions, when the NATURAL emissions have the same signal???
-Roy
Here is Roy Spencer’s essay, without any editing or commentary:
Atmospheric CO2 Increases:
Could the Ocean, Rather Than Mankind, Be the Reason?
by
Roy W. Spencer
1/25/2008
This is probably the most provocative hypothesis I have ever (and will ever) advance: The long-term increases in carbon dioxide concentration that have been observed at Mauna Loa since 1958 could be driven more than by the ocean than by mankind’s burning of fossil fuels.
Most, if not all, experts in the global carbon cycle will at this point think I am totally off my rocker. Not being an expert in the global carbon cycle, I am admittedly sticking my neck out here. But, at a minimum, the results I will show make for a fascinating story – even if my hypothesis is wrong. While the evidence I will show is admittedly empirical, I believe that a physically based case can be made to support it.
But first, some acknowledgements. Even though I have been playing with the CO2 and global temperature data for about a year, it was the persistent queries from a Canadian engineer, Allan MacRae, who made me recently revisit this issue in more detail. Also, the writings of Tom V. Segalstad, a Norwegian geochemist, were also a source of information and ideas about the carbon cycle.
First, let’s start with what everyone knows: that atmospheric carbon dioxide concentrations, and global-averaged surface temperature, have risen since the Mauna Loa CO2 record began. These are illustrated in the next two figures.
Both are on the increase, an empirical observation that is qualitatively consistent with the “consensus” view that increasing anthropogenic CO2 emissions are causing the warming. Note also that they both have a “bend” in them that looks similar, which might also lead one to speculate that there is a physical connection between them.
Now, let’s ask: “What is the empirical evidence that CO2 is driving surface temperature, and not the other way around?” If we ask that question, then we are no longer trying to explain the change in temperature with time (a heat budget issue), but instead we are dealing with what is causing the change in CO2 concentration with time (a carbon budget issue). The distinction is important. In mathematical terms, we need to analyze the sources and sinks contributing to dCO2/dt, not dT/dt.
So, let us look at the yearly CO2 input into the atmosphere based upon the Mauna Loa record, that is, the change in CO2 concentration with time (Fig. 3).
Here I have expressed the Mauna Loa CO2 concentration changes in million metric tons of carbon (mmtC) per year so that they can be compared to the human emissions, also shown in the graph.
Now, compare the surface temperature variations in Fig. 2 with the Mauna Loa-derived carbon emissions in Fig. 3. They look pretty similar, don’t they? In fact, the CO2 changes look a lot more like the temperature changes than the human emissions do. The large interannual fluctuations in Mauna Loa-derived CO2 “emissions” roughly coincide with El Nino and La Nina events, which are also periods of globally-averaged warmth and coolness, respectively. I’ll address the lag between them soon.
Of some additional interest is the 1992 event. In that case, cooling from Mt. Pinatubo has caused the surface cooling, and it coincides in a dip in the CO2 change rate at Mauna Loa.
These results beg the question: are surface temperature variations a surrogate for changes in CO2 sources and/or sinks?
First, let’s look at the strength of the trends in temperature and CO2-inferred “emissions”. If we compare the slopes of the regression lines in Figs. 2 and 3, we get an increase of about 4300 mmt of carbon at Mauna Loa for every degree C. of surface warming. Please remember that ratio (4,300 mmtC/deg. C), because we are now going to look at the same relationship for the interannual variability seen in Figs. 2 and 3.
In Fig. 4 I have detrended the time series in Figs. 2 and 3, and plotted the residuals against each other. We see that the interannual temperature-versus-Mauna Loa-inferred emissions relationship has a regression slope of about 5,100 mmtC/deg. C.
There is little evidence of any time lag between the two time series, give or take a couple of months.
So, what does this all show? A comparison of the two slope relationships (5100 mmtC/yr for interannual variability, versus 4,700 mmtC/yr for the trends) shows, at least empirically, that whatever mechanism is causing El Nino and La Nina to modulate CO2 concentrations in the atmosphere is more than strong enough to explain the long-term increase in CO2 concentration at Mauna Loa. So, at least based upon this empirical evidence, invoking mankind’s CO2 emissions is not even necessary. (I will address how this might happen physically, below).
In fact, if we look at several different temperature averaging areas (global, N. H. land, N.H. ocean, N.H. land + ocean, and S.H. ocean), the highest correlation occurs for the Southern Hemisphere ocean , and with a larger regression slope of 7,100 mmtC/deg. C. This suggests that the oceans, rather than land, could be the main driver of the interannual fluctuations in CO2 emissions that are being picked up at Mauna Loa — especially the Southern Ocean.
Now, here’s where I’m really going to stick my neck out — into the mysterious discipline of the global carbon cycle. My postulated physical explanation will involve both fast and slow processes of exchange of CO2 between the atmosphere and the surface.
The evidence for rapid exchange of CO2 between the ocean and atmosphere comes from the fact that current carbon cycle flux estimates show that the annual CO2 exchange between surface and atmosphere amounts to 20% to 30% of the total amount in the atmosphere. This means that most of the carbon in the atmosphere is recycled through the surface every five years or so. From Segalstad’s writings, the rate of exchange could even be faster than this. For instance, how do we know what the turbulent fluxes in and out of the wind-driven ocean are? How would one measure such a thing locally, let alone globally?
Now, this globally averaged situation is made up of some regions emitting more CO2 than they absorb, and some regions absorbing more than they emit. What if there is a region where there has been a long-term change in the net carbon flux that is at least as big as the human source?
After all, the human source represents only 3% (or less) the size of the natural fluxes in and out of the surface. This means that we would need to know the natural upward and downward fluxes to much better than 3% to say that humans are responsible for the current upward trend in atmospheric CO2. Are measurements of the global carbon fluxes much better than 3% in accuracy?? I doubt it.
So, one possibility would be a long-term change in the El Nino / La Nina cycle, which would include fluctuations in the ocean upwelling areas off the west coasts of the continents. Since these areas represent semi-direct connections to deep-ocean carbon storage, this could be one possible source of the extra carbon (or, maybe I should say a decreasing sink for atmospheric carbon?).
Let’s say the oceans are producing an extra 1 unit of CO2, mankind is producing 1 unit, and nature is absorbing an extra 1.5 units. Then we get the situation we have today, with CO2 rising at about 50% the rate of human emissions.
If nothing else, Fig. 3 illustrates how large the natural interannual changes in CO2 are compared to the human emissions. In Fig. 5 we see that the yearly-average CO2 increase at Mauna Loa ends up being anywhere from 0% of the human source, to 130%.
It seems to me that this is proof that natural net flux imbalances are at least as big as the human source.
Could the long-term increase in El Nino conditions observed in recent decades (and whatever change in the carbon budget of the ocean that entails) be more responsible for increasing CO2 concentrations than mankind? At this point, I think that question is a valid one.
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Well we’ll see. I don’t know if Spencer or Courtney’s ideas will bear out or not, but I’m willing to give them the benefit of the doubt, and to do so without being condescending in the process like Mr. “Swammi”.
I do like what Sean Carroll had to say, and getting the basics down is important, if not only to elevate credibility with others, but to help yourself see the outcome probabilities of paths you could choose.
We all have different ideas. Some will fail, some will fly. We shouldn’t start shooting skeet right away without first letting them all devlop some wings.
One thing I’m sure of, we don’t fully understand our earth-climate system, so there’s room for discovery.
Richard:
Don’t get me wrong. Nothing would delight me more than to be in error. And I admit the amount is smaller than the MoE. But it has rather steadily accumulated (according to measurements which may or may not be entirely accurate) through both cool and warm. That’s the reason it isn’t making it as such a great temperature proxy!
ER:
Oh, yes. Only the expert may testify. But never, ever forget it is the layman juror who must, in the end, “determine the facts”. The expert is excuded from the jury, and for good reason.
Mr. E.
I think you may well be right.
On the other hand, whether CO2 is the–main–driver of the recent warming measurements is yet to be seen. It does not correlate very well. And if Mr. Watts’ Inconvenient Photographs are any indication at all, the surface stations have actually been measuring encroaching heat sinks and waste heat for the last two or three decades.
A modest temperature increase is greatly exaggerated by a heat sink.
————————————————————-
And yes, the carbon cycle is indeed more involved. Here’s one I hammered together a while back from several sites (including the one RC provided:
The Greater Carbon Cycle
Air & Water
From: Organic Compounds/Animals (Decay, Cellular Respiration), Organic Compounds/Plants (Decay, Cellular Respiration, Combustion), Limestone, Coal, Oil (Industry), Volcanoes (CO2)
To: Plants (Photosynthesis), Limestone, Coal, Oil
Organic Compounds/Animals
From: Animals
To: Air & Water (Decay, Cellular Respiration)
Limestone, Coal, Oil
From: Air & Water
To: Air & Water
Plants
From: Air & Water
To: Animals, Organic Compounds/Plants
Organic Compounds/Plants
From: Plants
To: Animals (Consumption), Air & Water (Decay, Cellular Respiration, Combustion)
Animals
From: Organic Compounds/Plants , [ Plants ], [ Animals ]
To: Organic Compounds/Animals
Volcanoes
To: Air (CO2)
————————————————————-
And another take:
The Oxygen Cycle
Atmosphere
From: Animals (CO2), Plants (O2)
To: Animals (O2), Plants (CO2)
Plants
From: Atmosphere (CO2)
To: Atmosphere (Photosynthesis/CO2, Respiration/O2)
Algae
From: Water (CO2)
To: Water (O2),
Animals
From: Atmosphere (O2)
To: Atmosphere (CO2)
Atmosphere
From: Animals (CO2), Plants (O2)
To: Animals (O2), Plants (CO22)
Fish
From: Water (O2)
To: Water (CO2)
Water
From: Algae (O2), Atmosphere (O2, CO2)
To: Algae (CO2) Fish (O2), Atmosphere O2, CO2)
[I’ve also hunted up and compiled simple cycles for Energy (Greenhouse) Cycle, Nitrogen, Sulfur, Phosphous, Life Energy, and Water.]
Just an amateur look at the back-and-forth. At some point I am going to try to compile common carbon into a single entity. I may try to create link between the hydrogen aspects which run through many of these.
It’s all in the point of view. All a body has to do to make Ptolemy “correct” is to take a working solar system model, is grab it by the earth and then watch the sun and planets spin weirdly about …
I decided long ago that much of this debate about mankind’s relative impact on the planet could be resolved if only those involved stayed away from airplanes and drove the length of the continents by car.
Or by ox cart.
Steve Hemphill,
I used “two-variable” process for the emissions and temperature influences. The latter involves oceans and vegetation.
The interesting feature of temperature on oceans and vegetation is that the CO2 uptake/release is opposite of each other.
Oceans continuous release CO2 in the equatorial band (including deep ocean upwelling in the Pacific) and dissolve CO2 near the poles (including deep ocean downwelling by the THC in the North Atlantic). The main seasonal variation is due to the mid-latitudes, where changing ocean surface temperatures release CO2 in summer and absorb CO2 in winter.
Vegetation goes the opposite way: large CO2 uptake in summer (including ocean algues) and continuous release of CO2 during the year from vegetation decay (without uptake in winter from leafless trees).
This makes that the about 100 GtC exchange oceans/atmosphere and 50 GtC exchange vegetation/atmosphere are in countercurrent and cause only a 20 GtC (10 ppmv) global amplitude over the seasons. The one-way emissions are about 35% of the two-way seasonal flows in the atmosphere, but average 200% of the residual variability of the seasons over a year.
About ice cores (of interest for Mhaze too):
There is a difference between the lag of gas age after ice age dating and the resolution of the gas sampling. The lagging is a question of closing depth of the bubbles, while the resolution is a matter of diffusion of CO2 through the firn before the bubbles close and the number of layers necessary to have enough sample for a CO2 measurement.
For the Vostok ice core, the lagging is several thousands of years, but the resolution is about 600 years. The accuracy of the measurements are no way better than 1 ppmv, smaller variations are within the accuracy. The 8 ppmv/°C is based on the big shifts of about 10°C and about 80 ppmv for the ice age – interglacial transitions and reverse. That indeed are very long-term averages and probably involve the deep oceans, which is not the case for current (2-4 ppmv/°C) temperature changes.
High accumulation ice cores have a better resolution (about 60-80 years) and because of the one-way CO2 increase, the most recent layers only have a 10 years ice-gas age lag and a 5 years resolution. This resulted in an overlap of about 20 years for the Law Dome gas age data and the South Pole atmospheric measurements. The data of the South Pole atmosphere are within the +/- 1.2 ppmv accuracy of three ice cores (with different drilling methods) of Law Dome. See Etheridge ea.: http://www.agu.org/pubs/crossref/1996/95JD03410.shtml
The overlap is here: http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
About Beck’s historical data vs. ice cores: I don’t want to (re)start the discussion of Beck’s data here. It is sufficient to say that most measurements had an accuracy of 10 ppmv, but that most measurements were done at places where huge local production (vegetation as well as human emissions) was present. The only measurements taken at sealevel and/or coastal stations for the assumed peak period 1935-1950 (+ 100 ppmv 1942!) include the ice core values within the data variability.
And one need to take the comments of Jaworowski about ice core CO2 accuracy with a lot of salt, I noticed several remarks of him which simply aren’t true…
But I agree, even if human emissions are the sole cause of the increase, that doesn’t tell us anything about the influence of more CO2 on temperature…
“Or by ox cart.”
You would be surprised at the damage preindustial man did to the land. There are more of us today, but the environmental impact per person is miniscule compared with the past (and a good thing, too!). And that is mostly on account of the internal combustion engine. The IC engine has deletrious direct effects but many unsing indirect environmental (and other) benefits. And, above all, one must consider the overall environmental impact to land and air of what it replaced–bitumens, wood, and the horse–and those oxen you mention.
Consider that double-take line from Home onthe Range: “And the skies are not cloudy all day.” Also consider that Europe was one big forest, once.
There seems to be a consensus that the 3% of CO2 emissions that are anthropogenic are causing a rise in atmospheric CO2 concentration. Supposedly 50% of these emissions stay in the atmosphere. If this is true doesn’t it stand to reason that atmospheric CO2 concentrations would be falling if there were no anthropogenic emissions?
Taken to it’s logical conclusion one could conclude and then confirm with GCM’s that anthropogenic emissions are preventing a cascading runaway ice-age.
Ferdinand,
If you are trying to convey the idea that d13C isotope data could account for the exact contribution of manmade CO2 in the atm concentration increase, I must disagree.
Appart from saying that d13C ratios are “consistent” (see IPCC 4AR chapter 7) with anthropogenic CO2 emission, nothing QUANTITATIVE can be said by isotope observations, neither with d13C, nor with C14. We can go further with numbers if you want but you should have known numbers don’t sum up.
The CO2 balance is so fuzzy that current “theories” must rely on the anti-science notion of “missing sink” (rephrased “residual carbon sink” by the IPCC in 4AR, see Wood Hole) to account for what may happen to 1/3 of anthropogenic CO2 emissions.
So the questions raised by Drs Spencer and Courtney about the outcome and the real influence of manmade CO2 and the caveats about data (huge) uncertainties remain valid.
This is something the current science can’t say. Nobody knows if human emissions account for 30%, 60% or 100% of the concentration increase. So it’s out of the domain of refutability.
Ferdinand,
If icecores enables 5 y resolution CO2 measurements, we should have proxies data for up to year 2002 and plenty of them. The bubble close-off, reactive decay, diffusion… problems shouldn’t exist. But I’m not aware such data exist or are properly archived. Your Law Dome graph shows sparce data, “adjusted” with some methods, from different locations, with end date in the late 70s. Not exactly an illustration of a high quality 5 y resolution serie that would put to rest the divergence-calibration problem (between proxies and direct data).
I’m not saying such CO2 proxies don’t exist. I’d just love to see them.
Ferdinand,
Thanks for your input, it’s been very interesting. I’m not here to make any sort of case for or against, but to try to understand how it works better.
A few questions:
Where you say “More evidence for man-made increase is in the following” I don’t understand why some of those constitute evidence. The d13C/d14C levels show that fossil carbon has gone into the atmosphere and oceans, but doesn’t say the deep ocean hasn’t contributed any more (or less). Think of it as a tank of water with big pipes running in and other big pipes running out, and the rate of flow varying with both the level of the water, and some valves controlled by other stuff like temperature. You also pour in a small amount of dyed water. Now even if the flow has been varied by the big pipes, there’s still going to be an increasing level of dye in the water, until the concentration is high enough that the amount of diluted dye going out of the bigger pipes equals the amount of dye coming in. Certainly, not all of the dye is hanging around – that’s what Tom Segalstadt keeps going on about. The picture the layman normally gets is of a tank with tiny natural pipes in and out, and a huge anthropogenic pipe pouring in water with nowhere to go, and that all this new CO2 consists of fossil carbon. We need to get a clear picture of what is actually going on from the scientists, so that we can stop annoying them with these simplistic misunderstandings.
The oxygen level must decrease because carbon is being converted to carbon dioxide (and the hydrogen in hydrocarbons to water), but that doesn’t say anything about where it ends up. Is that oxygen ending up in the air or the water or the biosphere? Bringing in the oxygen cycle adds a whole new level of complexity, and would require a whole lot more discussion for us to be sure there was no other explanation for the lowering oxygen level. There may be good evidence there, but the argument is incomplete. Vegetation is a net sink of 2GtC/yr, but what if it would have sunk 4GtC/yr if it wasn’t for some other effect? Then that effect would be one of the causes of the accumulation. It doesn’t help me to understand.
The main argument I see is one you didn’t mention explicitly – that past temperature changes haven’t led to corresponding CO2 changes (unless there’s something badly wrong with CO2 proxies, which I’ve seen no convincing evidence for).
Ferdinand,
In a later comment, you speak of the 2-4 ppmv/°C sensitivity of CO2 levels to temperature. I don’t understand this figure. Firstly, the effect of temperature is surely on the flow, not the level? There ought to be some time units in there, unless you’re talking about some sort of equilibrium level? (Same goes for Dr Spencer, of course.) Secondly, what is that temperature? The global average, the average ocean temperature, or the temperature at the places where CO2 is absorbed/emitted? Since the solubility is a non-linear function of temperature, it matters, and you could possibly get some sort of effect from changes in distribution of temperatures (over time or location) without changing the average.
Similarly, you mention the seasonal temperature changes and their effect on CO2 level. The effect of the flow in and out of vegetation is a non-linear and integrated function of temperature, and the effect on the solubility pump is surely on the flow rate? This is the integrated change over about a year. If the 0.6C global mean anomaly change means a 2 ppmv change in CO2, and that is accumulated over 40 years, wouldn’t that give an 80 ppmv total? I don’t seriously think it works that way, but confusing rates with levels doesn’t make it obvious why such reasoning must be wrong.
I don’t know – your reasoning may well be perfectly correct for reasons that you’ve skipped over in order to be concise. But by skipping over them you just cause more confusion in those unable to fill in the gaps for themselves. They’re not convinced, they don’t understand any better, and when they find out that there are huge gaps in the argument you’ve given them (as they inevitably do) they immediately jump to the conclusion that they’re being taken for fools. (Take note, Eli and Swammi.)
Eli, There are many who would like to acquire a basic competency in the area, but when they try they at first find only these simplistic cartoon models, that are nevertheless presented by authoritative scientists as the truth. They can’t tell which ones are intended to be taken seriously, because they’re not told. When they start picking holes in them (as Dr Spencer has here), they’re told they’re fools and there’s another layer that the famous scientist didn’t explain to them, and an endless series of papers in journals they can’t get access to that each give one tiny bit of the jigsaw puzzle.
Make it easy for them. Provide an accessible explanation all in one place that fills in all the gaps and doesn’t fudge anything. (And everything elsewhere that is fudged should be marked as such.) As Richard Feynman said, if you can’t explain the science in terms an educated layman can understand, then you don’t really understand it yourself. And as Sir Arthur Conan-Doyle’s detective lamented so often, his feats of reasoning were always so absurdly obvious once they had been explained.
Ferdinand,
First off I must say I wholeheartedly agree that just because CO2 is increasing does not mean it is the causative agent of the warming of last century, which seems to either have begun to decline or plateaued, depending on which analysis you look at (except GISS, which for some reason is out there all by itself).
Then, Huxley said “The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, scepticism is the highest of duties; blind faith the one unpardonable sin.”
which dispenses with the dogmatic narrowmindedness of Swammi.
To the point of this particular discussion, CDIAC says the *average* difference in age between the ice and the air at a depth is 4,000 years. You say (I suspect well documented) that the resolution is within 600 years. Leaving alone for the moment the weighted bubbles below the 4,000 year mark, how do you explain that there is no mixing between open bubbles for over 3,000 years?
The Bohm et al’s delta-13-C data shown in Ferdinand’s graph does in NO WAY demonstrate human emissions cause the increase in CO2 atmospheric content. And certainly not in ocean (sic) CO2 content since no reliable measure exists there (if you are thinking about ocean pH change, forget about it, nobody has observed it apart from models).
Let me elaborate :
d13C is supposed to decrease because fossile CO2 – from oil, coal, nat gas – are depleted of C13 (d13C=-26/1000) compared to natural CO2 (-7/1000). So by measuring d13C, one *should* be able to know what percentage fossile CO2 accounts for the concentration increase.
Then using a simple mixing law, if you suppose concentration increase is due integrally to human emission (ie fossile CO2), you should observe a d13C = -13,3/1000. The problem, a big one, is that the real value you find is just -9/1000 that is just 30% of the target from the hypothesis & theory above.
Conclusion: contrary to what you hear very often but without further explanation, isotopic dosage can NOT tell you which % fossile CO2 accounts for the atmospheric increase. No way.
Ferdinand, Demesure.
I was just trying to indicate that extending the analysis back to say, 1880 with our best estimates of historical CO2 might yield some interesting results.
Do it with ice core dated CO2, and also with some group of historical CO2 by chemical means. Use the same analysis as for the recent period.
Might be something interesting there, might not. The fact there are controversies does not mean that entire period (1880-1955) should be excluded from study and analysis. Bad idea.
Dear all,
Here I try to address the most important points in Dr. Spencer’s and Richard Courtney’s essays where we differ in opinion.
Before we start, we need to be sure that we use the same definitions with the same meaning.
Definitions
Emissions is used for all increases by Dr. Spencer: as well as for the human emissions as for the increase in the atmosphere (whatever the source). In the following emissions is exclusively used for anthro emissions.
Accumulation is by several used as the increase in % within a mass (of CO2), while others (myself included) use it as an increase in total mass. We use in the following accumulation for both, but add “in %” or “in mass” to make the distinction.
The accumulation
Richard made a statement that the total CO2 into the atmosphere is 156.5 GtC, of which 150 GtC/yr from natural inflow and 6.5 GtC/yr from emissions. Of this only 3 GtC/yr accumulate in mass in the atmosphere, thus only 3/156.5 = 2% of all emissions accumulate in mass.
Here we see the first logical error: the 6.5 GtC/yr emissions are not a part of the seasonal cycle of about 150 GtC/yr, which is composed of about 90 GtC seasonal (summer, oceans) increase, about 92 GtC (winter, oceans) decrease, 61.5 GtC decrease (summer, vegetation) and 60 GtC increase (winter, vegetation). For an attempt to make a rough estimate (+/- 30%) of the seasonal flows, see Battle ea..
Thus while the accumulation in CO2 mass is only 2% of the inflows, the seasonal inflow is a part of a cycle and the total natural cycle shows a net loss of about 3.5 GtC/yr. Thus the natural cycle has a negative accumulation in mass to the atmosphere and the full accumulation in mass of 3 GtC/yr in the atmosphere thus is from the emissions. Which makes that about halve of the emissions accumulate in mass in the atmosphere.
How much of the original emissions in % accumulate in the atmosphere is of a different order. A lot of molecules is exchanged over the seasons and by continuous flows (equatorial to polar oceans). About 20% of the atmospheric CO2 molecules are exchanges between the atmosphere and oceans/vegetation over a year. That means that about 80% of the emissions accumulate in % in the atmosphere, the first year of the emissions. The next year, without further emissions, again 20% of all molecules are exchanged and 80% of 80% of one-year emissions stays in the atmosphere. Thus the half-life time (the time that 50% of any addition of specific molecules, in this case 13C depleted CO2 stay in the atmosphere) is about 5 years.
This is based on the fate of the one-time addition of extra 14C from nuclear bomb testing in the 1950-60’s.
The real accumulation in % of the emissions in the atmosphere can be calculated, as there is a decrease in d13C in the atmosphere (ice cores-firn-Mauna Loa). Of total atmosphere only about 8% is from the emissions (65/800 GtC), and from the upper oceans only 3.5% (35/1000 GtC) is from human origin. Total 100 GtC from human origin still reside in the atmosphere and upper oceans. The rest of the over 300 GtC emissions since 1850 is either somewhere in the deep oceans (unmeasurable in that mass) or in vegetation (only quantitative since 1990, calculated from oxygen measurements).
The influence of flows and mass
Richard makes a lot of the huge carbon reservoirs and huge flows between the reservoirs, compared to the small amount that humans add to the atmosphere.
To be short on this: reservoirs have not the slightest influence on other reservoirs (including the atmospheric reservoir), if there were no flows/cycles between them.
Take the deep oceans: the estimated flow of 100 GtC between deep oceans (38,000 GtC) and upper oceans is only 0.26% of the deep ocean carbon mass.
Carbon cycles have not the slightest influence on accumulation in mass, if there was no imbalance between the in and out flows. Of the about 100 GtC upper-deep ocean carbon cycle, only 1.6 GtC is the negative accumulation in mass of the upper ocean layer, or 0.16% of the upper oceans, or 0.004% of the deep oceans.
While we don’t know any of the in/out flows of the atmosphere with sufficient accuracy, we do know the emissions with reasonable accuracy and the increase in the atmosphere with quite good accuracy. The difference between emissions and measured increase is the net (negative) accumulation in mass of all natural cycles together. We don’t need to know any of the individual flows or cycles to any accuracy, as only the net difference of all cycles together accumulates as mass in the atmosphere. The data show that in almost all years, the accumulation in mass of all natural cycles together is negative. And thus only the emissions give a real accumulation in mass.
To show the logical error in Dr Spencer’s example:
Which is right, but even in this example, the accumulation in mass in the atmosphere from the natural cycle is -0.5 units and that of the emissions is 1 unit. The same result as if you have an ocean which produces 90 units and absorbs 90.5 units, while the emissions still are 1 unit.
Even the same result if you have a crossover: the oceans produce 90 units and absorb 89 units, vegetation produces 60 units and absorbs 61.5 units and the emissions still are 1 unit.
In all cases, the natural cycles accumulate in mass -0.5 units and the emissions still are accumulating 1 unit in mass… The net result in all cases is +0.5 unit accumulating in mass in the atmosphere.
As you can see, the individual flows of a cycle have not the slightest influence on accumulation in mass, if the cycle is in balance. It is the unbalance that accumulates in mass (positive or negative). Calculations which only include one-way parts of the cycle lead to illogical conclusions.
The saturation of the oceans
Richard assumes that the oceans are far from saturated, because of the rapid changes in CO2 flows with temperature variations during the seasons. While we can’t speak of “saturation” here, the rapid changes prove that the CO2 flows are influenced by temperature, which is responsible for an immediate change in pCO2 (partial pressure of CO2) in the surface layer of the oceans. With steady pCO2 in the atmosphere, the pressure difference between ocean pCO2 and pCO2 of the atmosphere changes and thus the flows from one to the other. The limiting factor in all cases is the diffusion speed between water surface and atmosphere, which is rather low, but increases with wind speed.
The same is true for an increase of pCO2 in the atmosphere by the emissions: this leads to less outflow from the equatorial oceans and more inflow into the polar oceans and similar changes during the seasons. The current difference between pCO2 air/oceans is about 7 ppmv (7 microatm).
See for a lot more information on this topic:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/exchange.shtml
That means that if the emissions should stop, next year there would be a drop of about 3 GtC out of the atmosphere, the second year about 2.4 GtC,… etc., until a new equilibrium is reached. The second cycle (upper-deep oceans) also remove CO2 from the upper oceans, which reduces the pCO2 of the upper oceans, which maintains to a certain extent the pCO2 difference air-upper oceans. Thus the second year, the drop will not be 2.4 GtC, but a little less than 3 GtC. Some more knowledgeable than me made a calculation, which resulted in an about 38 year half life time of the accumulation in mass caused by the emissions. This is governed by the pCO2 differences air/ocean.
What vegetation will do with decreasing CO2 levels is not easy to answer.
The half life time of the accumulation in mass of CO2 in the atmosphere is entirely different of the half life time of the accumulation in % in the atmosphere of the emissions, which is governed by the total carbon cycles between air and oceans/vegetation.
This was a long story, but it gives a good insight of the difference in opinion…
Regards,
Ferdinand Engelbeen
@Mhaze
That’s what Beck has done. And the results are divergent. That’s where the science is.
Ferdinand,
Just a clarification before further discussion (sorry if you have written it down).
Your numbers for CO2:
– human emissions since 1850: 300 GTc ending up in (1) + (2)
(1): 235 GT sequestered
(2): 65 GT in the atmosphere
– atmospheric increase since 1850 = +30% or 184 GT (615 GT in 1850-> 800 GT in 2006)
So if we stick to your numbers, that means the atmospheric CO2 increase since 1850 is
– 35% due to human CO2 emissions (65/184)
– 65% due to natural CO2 increase ((184-65)/184)
Do you mean that the CO2 increase is about 1 part manmade for 2 parts natural ?
I have noticed that when you but the ice core CO2 data into the air-measured CO2 there is a bigass divergence. You don’t need a PhD in snowballs to see that.
The air measures purport to start where the ice cores leave off. But is that raw or some funky adjustment to paste the ends together and make it look pretty? One thing is for sure: the air measure sure swoops off a heck of a lot faster than the ice cores!
Let’s look at the history. There was full war production in England from 1940, from Russia, from 1941, the US from 1942, and Germany, from 1943. (Not to mention Japan, which had been at war since 1937.) Not to mention blasting everything blastable including 100 cities (with several severe firestorms).
That’s a lot of damn CO2.
Then, after the war, there was a severe worldwide recession and retrenchment followed not until a few years later by what became the current industrial trend.
So where’s the wiggle in that suspiciously even graph, then? Do we have useful demographic data (numbers/types of factories, industrial output, coal/oil cinsumed, “car-mile” numbers, or whatever) from those days that can confirm these readings?
And what about the great Depression when a third to a half of industrial production simply–ceased? When gas was so dear that siphoning jokes were a very common form of humor?
So where’s Uncle Wiggles? Out to lunch?
Them there graphs is smooooooth. TOOOOOO smooth!
Evan wrote: “Them there graphs is smooooooth. TOOOOOO smooth!”
In the context of Roy Spencers essay, it could be said that the reason that you don’t see such expected perturbations such as WWII, etc, but we do see a slight perturbation with Mt. Pinatubo in 1992, speaks to the possibility that the human contribution of CO2 is swamped by natural contributors.
Human history is erratic, driven by politics, war, economy, disease, famine, and natural disaster.
If humans are the majority contributor to the Keeling CO2 curve, it would seem that it would be a bit more “wiggly” as you put it.
It stands to reason that the only things large enough to swamp the variance in signal of the human contributions would be earth’s own processes.
The ocean is a great low pass filter.
Since Evan is looking for “wiggles” I decided to supply some. Here is Mauna Loa annual CO2 that I plotted from CDIAC thanks to the link provided by Eli Rabbet. For some reason the data only goes to 2004, but it will do.
With the annual biomass respiration removed, it is easier to see the “wiggles”.
Full sized image link maunaloa-annual-co2.png
Your mission Mr. Jones, should you choose to accept it, is to use your skills as a student of history to put names on the “wiggles”.
(No Australian kids TV shows jokes please.)
Demesure,
The d13C argument is not the sole argument that the accumulation in mass is caused by the emissions. The mass balance is the best argument.
Even if not all sinks are known to any accuracy, neither the partitioning between vegetation and oceans (one of them even may be a net source), we know with reasonable accuracy that all natural flows together form a net sink of average 3 GtC/yr (ad that is the difference between emissions and accumulation in mass in the atmosphere). This proves that the emissions are the sole cause of the accumulation in mass (except for a small temperature influence).
It would be different if some source was missing (if the accumulation in mass in the atmosphere was larger than the emissions).
But the d13C fate effectively exclude (deep) oceans as source of extra CO2. That is the main point.
Indeed what we measure in the atmosphere as d13C decrease is about 1/3th of what a direct calculation gives. This can be the result of
a) dilution of the atmospheric d13C decrease by the natural cycle oceans (0-4 per mil d13C) – atmosphere (-8 per mil) – oceans.
b) dilution of the atmospheric d13C decrease by an extra addition of ocean CO2
a) can be reached by an about 70 GtC carbon cycle (deep) oceans – air – oceans. Not that different of the 90 GtC (+/- 30%) found by Battle ea.
b) needs about 21 GtC extra inflow (without outflow) of deep ocean CO2, to reach the observed less decrease in d13C than calculated. But we don’t see a 28 GtC (oceans + emissions) increase in the atmosphere, only a 3 GtC increase, less than the emissions alone.
Thus there is no extra input of CO2 from the oceans.
About the ice cores, you should read the full article. That gives the reasons for the adjustments, which are quite small. The end of the ice core measurements is at the end ’70s, as that is the age of the ice at bubble closing depth. At the same depth, the CO2 age is about 10 years younger. Therefore we have no later ice core data, but we have firn data, which show a further increase of CO2 until current levels.
There is no difference between open bubble and closed bubble CO2 levels at closing depth, thus no diffusion problems seems to occur at least at closing depth.
Reactive decay is more a problem in the Greenland ice cores (volcanic deposits, more acid) than in Antarctica.
Three ice cores were drilled with different methods (wet and dry) at 0.5, 5, 16 km from the summit of Law Dome. The difference in CO2 levels between the ice cores is within 1.2 ppmv (one sigma). The South Pole trend is 0.8 ppmv lower than the average ice core trend.
The difference between ice core measurements and proxy data (like stomata data) is that with proper equipment and handling, the ice cores give a rather good sample of the real atmosphere of many years to milennia ago, while proxies need some translation between what you measure and ancient reality…
Regards,
Ferdinand
Could be, could be. Either what you say is true, or the measurements are highly questionable, or some other option, because so far as I can see ain’t no slow, steady curve in man’s use of CO2.
I know there may be the demographic data to dispute this notion, but from where I sit, looking at it writ large and crude, I can’t see it. I see seriuous ups and downs in man’s CO2 output.
Yeah, it’s a small percentage in the overall input/output matrix, but according to the the AGW advocates man IS the delta–a little less than half accumulating in the atmospheric sink and and rest winding up in the other two sinks, land and sea (a lot of that second half having routed through the atmosphere first).
If the AGW advocates are right, fluctuations in man’s output MUST change the curve (or why even bother cutting back?). They HAVE fluctuated (I contend). So why does the curve not reflect this?
Unless the “Rev” Watts is right? Wouldn’t be the first time, would it?
I’m surprised some historian or demographer has not pointed this out previously. (Heck, I’m surprised I never pointed this out previously.)
“A challenge to Roy Spencer, Richard Courtney, Stevo, Andrew and Steve Hemphill (and others): Demonstrate publically your skills in the scientific method by addressing the following —
Using known and established tenets of geochemistry and physical chemistry, describe how the delta-13-C data shown in Figure 4 of Bohm et al (2002) (conveniently provided by Mr. Engelbeen in his post as http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif ) does or does not support your theory that anthropogenically produced carbon (derived from fossil fuels) is NOT the cause of the increase in the content of atmospheric (and ocean) carbon dioxide shown by peer-reviewed data to have occurred in the last 1,000 years. ”
Demesure, I assure you that that is emphatically NOT what I said. I speculated that Oceans may MODULATE our emissions going into the atmosphere. It is not, as Ferdinand seems to believe, either, that I am saying that the oceans have a large effect that outweighs our input. I am simply stating that, again, the oceans are a sink, but not a constant one, and therefore that is the reason for the match between growth rate and temperature. I really wish my position wouldn’t be mischaracterized this way.
Demesure,
There is a lot of people which have problems to understand the difference between the two figures, you are by far not alone…
The 65 GtC is what is left of the original molecules of the emissions in % (accumulated in % of the atmosphere) of the atmosphere (which is diluted by the carbon cycles at a rate of 150/800 GtC per year).
The 184 GtC is what is accumulated in mass in the atmosphere, due to the emissions (which is diluted by the difference in in/outflows of the carbon cycles at a rate of 3/800 GtC per year).
Thus while the accumulation in mass is due to the total number of molecules added by the emissions, even during the year of emissions, about 20% (or more, depending of the distance between sources and sinks) is already exchanged with molecules of other origin. That alters the composition in %, but not the total mass…
To use the example of Segalstad: if you add a red colored small flow into a big tank where a lot of single in/outflows and cycles are in perfect balance, then the red color will be diluted in ratio with the total flows, while the total volume will increase with the total extra flow, independent of the rest of the flows and cycles…
MHaze,
Beck has made a graph of both the ice core data and the historical measurements:
See: http://www.biokurs.de/treibhaus/180CO2_supp.htm the graph is top left of the different graphs.
Warning: historical chemical data to be taken with caution. The 1942 about 100 ppmv (!) peak value is composed by a lot of data from places where the authors warn that they measured soil/plants/human emissions CO2… Even experiments set up to measure plant CO2 exchanges (rice fields 1941-1943, Misra, India) are included…
Evan Jones and Anthony,
You forget the difference in scale between the human additions and natural variations. The human additions are about 3.5 ppmv/yr, of which about 1.5 ppmv/yr accumulates in the atmosphere, the natural variations are within +/- 0.8 ppmv/yr, both to be observed at a scale of 380 ppmv.
Thus no wonder that the graph looks smooth, very smooth! Only extreme increases (like the 1998 El Niño) and extreme coolings (like the 1992 Pinatubo) can be easely observed.
The difference between the emissions and the natural variation is that the emissions caused the entire increase of 60 ppmv 1959-2004, while natural wobbles caused a temporarely change of a few ppmv, followed by normal temperatures (and CO2 increases, 1994) or even cooler periods (1999)…