Guest Post by Willis Eschenbach
Anthony has pointed out a new paper by McKinley et al. regarding the carbon sinks of the oceans (preprint available here , supplementary online information here). The oceans absorb and sequester carbon from the atmosphere. As usual in this world of “science by press release”, the paper has already been picked up and circulated around the planet. CNN says:
The ability of oceans to soak up atmospheric carbon dioxide is being hampered by climate change, according to a new scientific study.
A fresh analysis of existing observational data taken from locations across the North Atlantic Ocean recorded over a period of almost three decades (1981-2009) has revealed that global warming is having a negative impact on one of nature’s most important carbon sinks.
“Warming in the past four to five years has started to reduce the amount of carbon that large areas of the (North Atlantic) Ocean is picking up,” said Galen McKinley, lead author and assistant professor of atmospheric and oceanic sciences at the University of Wisconsin-Madison.
Figure 1. An estimate of the net CO2 flux into and out of the oceans, from Takahashi 1999. McKinley et al. say that the flux into the ocean is slowing.
The lead author says in the press release that things are getting worse … but since it is nearly guaranteed that the paper says something different from the spin the press release authors put on it, what does their paper actually say?
The first oddity about the paper is that they are discussing changes in the partial pressure of CO2 in the ocean (written as “pCO2”). But they’re not actually measuring the pCO2. They are calculating it from the dissolved inorganic carbon (DIC), alkalinity (ALK), sea surface salinity (SSS) and sea surface temperature (SST). Now, this is a standard scientific procedure used to estimate unknown variables in the oceanic carbon balance. But while it is generally a good estimate, it is still an estimate. It is calculated using an empirical formula, that is to say, a formula which is not based on physical first-principles. Instead, an empirical formula uses observation-derived parameters in an iterative goal-seeking algorithm to solve a complex formula.
As you might imagine, different authors use different parameters in the equation. There is a good overview of the function as it is used in the R computer language located in the “seacarb” package. If we take a look at the function “carb” in that package we see that in addition to the pCO2 depending on the variables they have measured, it is also affected by the levels of phosphate and silicate (which apparently the authors have not included). They give details of the different possible choices of values for the various parameters. From the description of the function “carb”:
The Lueker et al. (2000) constants for K1 and K2, the Perez and Fraga (1987) constant for Kf and the Dickson (1990) constant for Ks are recommended by Dickson et al. (2007). It is, however, critical to consider that each formulation is only valid for specific ranges of temperature and salinity:
For K1 and K2:
• Roy et al. (1993): S ranging between 0 and 45 and T ranging between 0 and 45oC.
• Lueker et al. (2000): S ranging between 19 and 43 and T ranging between 2 and 35oC.
• Millero et al. (2006): S ranging between 0.1 and 50 and T ranging between 1 and 50oC.
• Millero (2010): S ranging between 1 and 50 and T ranging between 0 and 50oC.
Millero (2010) provides a K1 and K2 formulation for the seawater, total and free pH scales. Therefore, when this method is used and if P=0, K1 and K2 are computed with the formulation corresponding to the pH scale given in the flag “pHscale”.
For Kh:
• Perez and Fraga (1987): S ranging between 10 and 40 and T ranging between 9 and 33oC.
• Dickson and Riley (1979 in Dickson and Goyet, 1994): S ranging between 0 and 45 and T ranging between 0 and 45oC.
For Ks:
• Dickson (1990): S ranging between 5 and 45 and T ranging between 0 and 45oC. • Khoo et al. (1977): S ranging between 20 and 45 and T ranging between 5 and 40oC.
As you might imagine, results depend on the choice of parameters.
In addition, McKinley et al. do not have observations for all input variables for all periods. Their study says:
For 2001-2007, ALK [total alkalinity] was directly measured. For 1993-1997, ALK was estimated from the ALK-SSS [sea surface salinity] relationship derived from 2001-2006 data (ALK = 43.857 * SSS + 773.8).
I bring these issues with the carbon calculations up for a simple reason—errors. Obviously, when you are estimating a critical value (pCO2) using an empirical formula with a choice of parameter values, with missing observations, and not including all of the known variables, you will get errors. How big will the errors be? It depends on the exact location being studied, the values of the various input variables, and your choice of parameters. As a result you will have to “ground-truth” the formula for the various biomes of interest. “Ground-truthing” is the process of comparing your calculations to actual measurements in the physical locations of interest. Once you have done that you can use the measured error, as well as any bias, in determining the significance of the results.
There is a discussion here of the oceanic carbon calculations, and some graphic examples of both calculated and measured pH, showing the size of the errors in another similar study. See in particular their Figure 1, which shows that errors in the calculation of pH, while generally moderate in size, are pervasive, unpredictable, and at times large.
Whatever the size of the errors resulting from the oceanic carbon calculations, they need to measured against observations in the regions studied, and then described and accounted for in the study. As far as I can tell the authors have not done either of these things.
The second oddity about the paper also involves errors. They have not (as far as I can tell) adjusted their error values for autocorrelation. Autocorrelation is a measure of how much tomorrow’s temperature is dependent on today’s temperature. As you know, warmer days are generally followed by warmer days, and colder by colder. It is unusual to see an ice-cold day in between two warm days.
Since when it is warmer it tends to stay warmer, and when it is cooler it tends to stay cooler (temperature records show positive autocorrelation), this means that the swings in the temperature will be larger and longer than we would find in purely random data. As a result, we need to adjust the calculations depending on the level of autocorrelation, in order to decide if the trends (or the difference between the trends) is statistically significant or not. As far as I can tell, the authors have not adjusted for autocorrelation.
The third oddity is one that I really don’t understand. The authors use a standard method (a “Student’s T-test”) to determine the uncertainty in the two trends, the trend in the pCO2 in the ocean, and the trend of CO2 in the atmosphere.
Then they use another test to determine if two trends (oceanic and atmospheric) are different. From their paper, here’s their description of the test, which contains the reason for the title of this piece, “Lowering the Bar”.
Figure 2. The description of the significance test used in to determine if trends are significantly different or not.
The “p-value” that the authors discuss is a measure of how unusual a result is. For example, if we flip a coin five times and it comes up heads every time, does that mean that the coin is weighted to come up heads? Or is it just a random outcome? The p-value gives us the odds that it was just a random outcome.
In the hard sciences, people like to see a p-value that is less than 0.001 (written as “p<0.001”). This means that there is only one chance in a thousand (1 / 0.001) that it is just a random outcome.
In climate science, the bar is generally lower. A result with a p-value less than 0.05 is regarded as being statistically significant. A p-value of 0.05 means that there is one chance in twenty (1 / 0.05) that whatever you are looking at is just a random fluctuation.
(As a brief aside regarding the use of p=0.05 as significant , consider that a scientist may look at a variety of datasets trying to find the “fingerprint” of a hypothesized mechanism such as anthropogenic global warming. Suppose on the sixth dataset he examines, he finds an effect which is significant at p=0.05. What are the odds that this is a chance occurrence? The odds are not one in twenty, because he’s looked at several datasets, so his odds of hitting a random jackpot have increased. In this case, if he finds it on the sixth try, the odds are already one in four that it’s just random chance, not a real phenomenon. End of digression.)
Now, if I understand what McKinley et al. are saying above (which I may not, all corrections welcome), they are saying that in their study a p-value less than 0.317 is considered statistically significant. But at that level of p-value, the odds of what is observed being merely a random phenomenon, something occurring by pure chance, is about one in three. One in three? … what am I missing here? Is that really what they are claiming? I’ve read the paragraph backwards and forwards, and that’s how I understand it. And if that’s the case, they’ve lowered the bar all the way to the ground.
In mystery,
w.
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Floor Anthoni says:
July 12, 2011 at 5:25 pm
He arrives at 150ppm per degree C, more than enough to explain all ‘anthropogenic’ CO2 since the industrial age, all coming from the sea.
Sorry, but the conclusion of the late Lance Endersbee is completely bogus: he used a 21 year moving average for the temperature over a less than 30 year period, which is the period with the largest temperature increase. If you use the full period 1900-current without such smoothing, the “excellent” correlation between temperature and CO2 increase falls down, while the correlation between human emissions and increase in the atmosphere is excellent for any period (of at least a decade) for over 100 years…
See: http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_acc_31.jpg
and
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_2004.jpg
and
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
Further, the temperature-pCO2 curve is known for different salt/DIC contents and pH/alkalinity values of seawater. The temperature influence is only 16 ppmv/°C in average, far from the 150 ppmv “estimate” of Endersbee. In a complex world, the other side of the earth increases its uptake of CO2 with higher temperature, making that the real world effect of temperature on the CO2 level equilibrium is around 8 ppmv/°C.
See:
http://www.ldeo.columbia.edu/~csweeney/papers/NOAA_appxdD.pdf
The pCO2 in surface ocean waters doubles for every 16°C temperature increase.
For the average seawater temperature of 15°C, that means that the pCO2(aq) shifts from about 250 microatm to 500 microatm with a 16°C increase, or an increase of about 16 microatm/°C.
If N(x) is the standard normal CDF, N(1) – N(-1) = .683, so this is apparently where the authors’ .683 and .317 are coming from, and so they are indeed using a 2-tailed p-value of .317 as their criterion for “significantly different”.
In economics, RA Fisher’s arbitrary and admittedly rather high value of .05 is the usual threshold of “statistical significance.” In truth, this should be regarded as merely “noteworthy”, anything less being “not noteworthy”. I usually describe .05 as “significant” and give it one asterisk but hope for .01, or “highly significant” (two asterisks). If I’m desperate, 0.1 is “weakly significant” and rates a dagger note. In a process of star-inflation, many less-discerning economists give .10 one star and .05 two stars. But calling 0.3 significant would be considered laughable in any journal outside Nature Geoscience.
A further problem (besides serial correlation) may be that in Willis’s quote they they describe their test as employing only one of the two standard errors (which one?) instead of incorporating both (resulting in approximately 1.41 times the single se if the regression errors are independent). But I haven’t looked at the quote in the context of the actual Nature Geoscience article.
Don K:
This is how I make a double arrow:
Hope that solves the problem. Good post btw. GK
Don K:
Sorry, that obviously didn’t work here. GK
Nick Stokes says:
July 13, 2011 at 3:54 am
And I think they shouldn’t have written the paper at all. But ignoring both of our wishes, they did write the paper, and they did use the word “significance”.
Sorry, that doesn’t agree with what they said. They are talking about statistically significant differences between trends. They say:
So yes, they are definitely testing for significance, and they are using 0.317 as the critical value … you sure you want to continue to argue in favor of that?
I don’t understand why you are looking so far afield to try to find something, anything at all right with this paper. It is garbage from start to finish. The fact that you are defending it speaks volumes about the weakness of your general claims. If you need to rescue this paper from the rubbish bin to make your case, you’re backing the wrong horse here …
w.
2 sigma away from a mean (p = 0.05) is what is required in statistics to be considered significant (only 5% of the normal population distribution around a mean remains at this point; so if your mean is below the 0.05 marker, it’s likely to be a new mean and not simple random points from the mean you are testing against). This is a STATISTICAL fact, and is regardless of the field of science being used. You can make the criteria for significance even higher, such in material sciences and engineering, from the outset as is needed (by stating it outright), but for statistics itself, 0.05 is the accepted minimum value for a p to be beneath for significance to be established.
1 sigma is NEVER significant.
Engelbeen, let’s check some reality here.
1) Lance Endersbee used reliable data which unfortunately does not cover a long time span. He then applied a strong averaging filter, which is entirely appropriate since this simulates the ocean’s inertia. The outcome is surprisingly linear and is the only inconvenient fact giving an indication of the ocean’s overall rate of outgassing. What Takahashi et al are trying to do with local CO2 ocean fluxes will not lead to any idea what the oceans are doing in their totality – never. Just look at their graphs and the doctored false colour scale. Look at the huge range of values both positive and negative, in their publications.
2) what you are doing is taking a correlation serious, a correlation based on half century of reliable CO2 data, spliced onto a multiple-century curve of doctored data (ice cores), doctored and spliced precisely (as a hockey stick) to make the CO2 to temperature correlation look perfectly linear, and therefore convincing. This is Voodoo science.
Oops, last sentence: … CO2 to cumulative emissions correlation look perfectly linear,…
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
Wonder how much OCO the underwater active volcanos are adding to the ocean where the water is nice and cold and solubility is high?
e.g.: http://news.yahoo.com/huge-underwater-volcanoes-discovered-near-antarctica-021204714.html
Floor Anthoni says:
July 13, 2011 at 1:41 pm
I don’t think this is the proper place to repeat all the arguments again, but a short reply:
1. Lance Endersbee used reliable data which unfortunately does not cover a long time span.
While the reliability of the SST data is subject to some discussion (see CA today), my points are: why did Endersbee use only SST since 1980 and not since 1850 or (if he didn’t trust the ice core CO2 data) since 1960 to compare with CO2? Even the filtered temperature data are negative in the period 1960-1970, with increasing CO2, so where leads that for the correlation? And such a heavy smoothing makes even the worst correlation better between two upgoing variables.
2. a correlation based on half century of reliable CO2 data, spliced onto a multiple-century curve of doctored data (ice cores)
I have far more confidence in ice core CO2 data than in historical CO2 data taken at places where the variability of CO2 levels within one day varies between 250 and 600 ppmv. But to show you that there is nothing wrong by splicing in this case, here the separate comparisons for the periods 1900-1959 (ice cores) and 1960-2004 (Mauna Loa):
Temperature – atmospheric CO2 1900-1959:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_1959.jpg
I have not made the 1960-2004 comparison for temperature and CO2 but 1900-2004 is here:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_2004.jpg
Note that no matter what the temperature does, even with drops and increasings of halve the temperature scale, CO2 simply continues to go up.
Now accumulated emissions 1900-1959 vs. atm. CO2 increase (ice cores) 1900-1959:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_1959.jpg
Not bad, despite relative larger errors in CO2 emission estimates and CO2 measurements.
And based on far better inventories and measurements (Mauna Loa and South Pole) here for 1960-2006:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1960_2006.jpg
My conclusion is that temperature has a small, fast influence (about 4 ppmv/°C) on the variability around the trend, but that the trend itself is almost completely caused by the emissions. Or give me a simple explanation why nature would follow the emissions in such a fascinating extremely linear way…
Engelbeen:
1. The oceans contain 40,000 Gt carbon against an atmosphere of 700 (round figures here). Henry’s law insists that about 3% outgases for every degree C. For the whole ocean thus 1200 Gt = 700ppmv, or 700/50 = 14 ppmv per degree C for each 100m of ocean depth. The regularly perturbed layer is at least 600m which means that 80ppmv is easily released for each ºC. Nobody knows how much deeper perturbation goes, but these figures are BIG even though some oceans breathe in whereas others breathe out. (We’re not taking into account the biological side)
2. Reliable data for average ocean temperature is still not available, but certainly not before 1984. Now that over 3000 drifters do the rounds, more accurate data must eventually become available. Even so, it will be difficult to establish what the ‘effective’ average ocean temperature is in terms of ocean-CO2 breathing, also since wind speed plays a role. Now that the world began cooling, we may see what is really going on. Even so, the Mauna Loa and other CO2 data will first be ‘corrected’ and ‘adjusted’ to support the orthodoxy, as was/is done with land temperatures and satellites.
3. The linearity of CO2 in air vs cumulative emissions is indeed creepy but it is only a correlation. It is equally creepy that CO2 rises linearly for an exponential increase in emissions. To explain it as ‘the sea/environment absorbs a fixed percentage’ is perhaps just too simple. For instance, a higher concentration of CO2 encourages plants to grow more vigorously but it takes a while before carbon enters the soils from where it stimulates plant growth further. In a carbon-starved environment, which Earth really is, plant growth should react exponentially with increasing levels of CO2. Thus by leaving a linear increase in air, the environment is capable of sequestering an exponential increase in emissions. Remember, increased sequestration is not possible without increased concentration in air. So this is a simple explanation for you. (Note that experimental growth measurements on plants have been too short of duration to allow the soil to sequester carbon. Also many experiments were conducted in pots.)
For me the jury is still out. Time will tell.
tallbloke-“… you can see changes in the rate-of-change of co2 always lag the changes in the rate-of-change of sea surface temp by 6-9 months.”
My comment was made in some haste, purely in answer to the question of whether there was a connection. Yes there is a lag of around 6 months, with temperature preceding CO2, in my graph the CO2 curve was moved back 6 months to line up visually.
In figure 2, I notice that in the quoted text, it’s not “Student’s t-test” but “a student t test”. This is, I believe, an unconventional way if not incorrect way to describe in a scientific paper the proper name of the test. Goes to the writers knowledge as well as the reviewers and editors. GIGO
Floor Anthoni says:
July 13, 2011 at 6:43 pm
Floor, here a short (?) answer to your points:
1. Henry’s law insists that about 3% outgases for every degree C.
Henry’s Law is about pressure, not about % of a content. That is an essential difference. According to solubility parameters of CO2 in seawater (including all dissociation reactions), the temperature influence on the water phase CO2 pressure is about 16 microatm/°C. Thus a 1°C increase in temperature of even the upper few meters of the oceans increases the pCO2 of the ocean water at the surface with 16 microatm. If the pCO2 pressure of the atmosphere is increased with 16 microatm (about 16 ppmv), the net result is zero CO2 transport between the oceans and the atmosphere (if there was a previous _dynamic_ equilibrium between atmosphere and ocean surface).
16 ppmv increase of CO2 in the atmosphere means that a release of 32 GtC (as CO2) into the atmosphere is sufficient to compensate for 1°C increase in seawater temperature, no matter if that comes from the (deep) oceans or from humans. Thus it doesn’t matter at all how much carbon is in the (deep) oceans or what the temperature in the deep is, only the ocean surface temperature matters with a relative small influence on atmospheric CO2 levels.
The human emissions nowadays are about 8 GtC/year, or about 4 ppmv increase per year. Even only after 4 years, that surpasses the effect of 1°C increase of the oceans surface. From a lot of studies, it is clear that both vegetation and oceans are net sinks for CO2, which together remove about halve the amount of CO2 injected by humans (in quantity, not in individual molecules). Oceans remove about 2/3rd, vegetation 1/3rd of 4 GtC/year.
2. Reliable data for average ocean temperature is still not available, but certainly not before 1984.
Agreed, but I think that the “consensus” (including most of the sceptics) agree that there was a cooling in the period 1945-1975, which is hardly compatible with increasing CO2 levels, if the oceans were the main source.
Even so, the Mauna Loa and other CO2 data will first be ‘corrected’ and ‘adjusted’ to support the orthodoxy
Wow, that is a firm accusation. Any proof of that? All raw data (calculated from 1 hour of 10-second samples and calibration) for 4 stations (including Mauna Loa and the South Pole) are on line, up to 2009 at:
ftp://ftp.cmdl.noaa.gov/ccg/co2/in-situ/mlo/
These are all the data, without any correction or adjustment. For daily, monthly and yearly averages, only “selected” data are used, which are not contaminated by local air masses (volcanic or valley vegetation in the case of Mauna Loa). But no matter if you use all raw data or only selected data, the final result is the same: levels and trends are within 0.1 ppmv of each other.
BTW, the rules for calibration, calculation and inclusion of the data for averaging are here:
http://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html
3. The linearity of CO2 in air vs cumulative emissions is indeed creepy but it is only a correlation. It is equally creepy that CO2 rises linearly for an exponential increase in emissions.
Have a better look at the increase in the atmosphere, that also increases slightly exponentially:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_acc_31.jpg
That means that the sinks also increase exponentially, which results in maintaining a more or less fixed percentage of the emissions. The whole carbon cycle reacts as a simple linear first order process to the disturbance in the atmosphere, caused by the emissions…
BTW, increased plant growth over the past decades is measured by the oxygen balance. The 100+ ppmv increase since the industrial revolution (60+ ppmv since Mauna Loa started 50 years ago) did result only in 1.5 GtC/year (0.7 ppmv/year) extra sequestering of CO2 by vegetation.
Engelbeen,
1. Henry’s law states that “the solubility of a gas in a liquid at a particular temperature is proportional to the pressure of that gas above the liquid.” In practical terms it is also about how much gas dissolves in a liquid at a certain temperature. For all practicality, it has been measured for CO2: http://www.seafriends.org.nz/issues/global/global16.gif. Which leads to the stated 1200 Gt per ºC for the whole ocean. This is a pretty hard fact from which my further calculations follow. How else do you think the oceans contain that much CO2? Remember that it is quite valid to apply this to the whole ocean because when oceans warm, the places breathing out will do more so while the places breathing in will do less so, in equal measure.
2. I did not say that the CO2 measurements of Mauna Loa et al. were inaccurate NOW but the daily variations leave enough leaway to doctor the results LATER when they become inconvenient. Just wait; we’ve been there before, WITHOUT EXCEPTION.
3. the CO2 growth curve indeed curves upward slightly but negligibly so, and in accordance with warming seas. If uncertainty were plotted (as it should BUT NEVER IS), the curve remains well within linear bounds. When you read the esrl.noaa link you provided, carefully, you will notice that their selection criteria are entirely arbitrary. Which leaves me with justifiably deep suspicions.
4. The oxygen balance has been discontinued for a long time for good reasons – it has deep flaws. Rather than explaining these here, I refer to http://www.seafriends.org.nz/issues/global/climate4.htm#missing_oxygen
Just wait and see.
Floor Anthoni says:
July 14, 2011 at 5:03 pm
1.Henry’s law states that “the solubility of a gas in a liquid at a particular temperature is proportional to the pressure of that gas above the liquid.”
A more complete definition is at Wiki:
“At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.”
At a given pressure of CO2 in seawater, CO2 will come out if that pressure is higher than the partial pressure in the atmosphere (as happens near the equator), or get in, if the pressure is lower than in the atmosphere (as happens near the poles). With sufficient time and constant temperature, as much CO2 is going into the oceans as is coming out, a dynamic equilibrium is at work. At that moment, the (weighted) averages of pCO2(aq) and pCO2(atm) are equal.
If you increase all surface seawater with average 1°C, pCO2(aq) increases with about 16 microatm. Thus more CO2 will be emitted from the sea surface into the atmosphere than reverse. This increases the amount and thus pCO2 of the atmosphere, until after some time the increase reaches 16 microatm (~ 16 ppmv). At that moment a new dynamic equilibrium is reached and the streams in and out between atmosphere and ocean surface will be equal again. Only 32 GtC is needed to give the necessary increase in partial pressure in the atmosphere to reach a new dynamic equilibrium. No matter how much CO2 is in the oceans, no matter what the temperature of the deeper layers is.
The figure you provided is for CO2 in pure water, which is completely inapropriate for seawater, which contains Ca and Mg ions, mainly in the form of carbonates and bicarbonates. This makes that seawater contains far more CO2 than according to Henry’s Law, because only 1% of all CO2 in seawater is free CO2 (or H2CO3), which obeys Henry’s Law. See:
http://www.eng.warwick.ac.uk/staff/gpk/Teaching-undergrad/es427/Exam%200405%20Revision/Ocean-chemistry.pdf from page 5 on.
2. Mauna Loa is not the only station where CO2 is measured. There are some 70 places in “background” areas, maintained by different groups in different countries, independent of each other. Don’t you think that at least some of them will protest if someone tries to manipulate the figures?
3. The uncertainty of the emission estimates (based on fuel sales and burning efficiency) nowadays is not too bad (-0.5 to +1 GtC), the uncertainty of the global CO2 levels (average of several sealevel stations, Mauna Loa not included), is +/- 0.4 GtC (+/- 0.2 ppmv) around a trend of +120 GtC (60 ppmv) in the past 50 years. Simply negligible.
In the period 1945-1975 (or 1960-1975, if you don’t trust the ice core data), ocean temperature trend and CO2 trend are opposite.
Even including all outliers of the CO2 data doesn’t change the average or trend. Only the variability increases.
4. Your calculation of oxygen use from fossil fuel burning does only account for the carbon in the fossil fuel, not for the hydrogen. That makes that you underestimate the oxygen use for other fuels than coal: a factor 1.5 for oil and a factor 2 for natural gas. The oxygen measurements just are going on, see:
http://bluemoon.ucsd.edu/images/ALLo.pdf
Floor,
Some addition to your point 4. From your website:
During that decade humans burnt 65GtC or 30ppmv of which 57% or 17ppmv remained in air. During that same period, about 200 per meg = 200 / 4.8 = 41ppmv oxygen went missing, or nearly 2.5 times as much. We can account for 17ppmv oxygen but not for the remainder
In addition to the underestimating of oxygen use for oil and natural gas, what is used as oxygen is for 30 ppmv CO2, not 17 ppmv. It is not relevant for the amount of oxygen used how much CO2 remained in air, only what was emitted. Thus the final sum is:
30 ppmv O2 for the carbon in fossil fuels + x ppmv O2 for the hydrogen in oil and gas.
As oil uses 1.5 times O2 compared to its carbon and gas 2 times, that makes that the 41 ppmv O2 use is plausible, as oil and gas are a large part of fossil fuel use.
If you want, you can figure it out exactly how much O2 is used, as the inventories of the use of the different types of fuel are available. See further where these calculations lead us:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
Engelbeen,
1. You don’t seem to grasp the CO2 situation:
a. there is no equilibrium. CO2 flows constantly from the sea through air to the land when the seas warm, and back when they cool.
b. during ice ages the land is poor, whereas in warm interglacials it is rich, sustaining and powering growing civilisations.
c. plants would grab more CO2 from air if they could, but they are starved. Only a higher level in air allows them to grab more. They don’t care where that CO2 comes from.
d. you cannot have global warming without also an increase of CO2 in air and slight acidification of the sea.
e. human CO2 plays a negligible role.
f. the effect of temperature far exceeds that of human contributions.
g. concentrations in air have a negligible effect on the sea.
2. Your last point taken. I have to check this further. Still, we are talking about correlations, trying to figure out whether the tail wags the dog or the other way round.
3. HOWEVER, why are we worried about more CO2 wherever it comes from? It is a highly beneficial gas which does NOT affect temperature, as has extensively been proved by many criteria:
a. none of the model predictions have come true, thereby decisively disproving the global warming hypothesis. The models have proved themselves wrong.
b. temperature always leads CO2.
c. many thermometer stations disprove the hypothesis.
d. in distant epochs there were periods with high CO2 and low temperatures.
e. temperature on Venus between 1 and 0.2 bar (our troposphere) follows exactly that of Earth. http://www.seafriends.org.nz/issues/global/climate1.htm#Venus_atmosphere. In other words there are no greenhouse gases, or any gas is a greenhouse gas, mainly nitrogen.
f. never has empirical evidence been found for the hypothesis.
4. what society MUST do is just:
wait and see.
Floor,
1.a. I am very aware of the CO2 situation: CO2 levels are dynamic: that means if the temperature fluctuates, so does the inputs and outputs of the atmosphere. In opposite direction for ocean surface and vegetation.
For seasonal changes over the full globe, the variation is about 5 ppmv for 1°C. A double amplitude in the NH, a halve amplitude in the SH. The variation is mainly by vegetation, not by the oceans, as the 13C/12C ratio shows.
The (weighted) average of pCO2(aq) is lower than the pCO2(atm), thus the oceans are a net sink for CO2, not a net source (averaged over a year).
1.b. From ice cores, we know that there was a firm correlation between temperature and CO2 levels on earth over the past near million years: about 8 ppmv/°C over glacials and interglacials. If you don’t trust the ice cores, similar changes were found in foramins (and roughly in stomata data). Even in current times, the variability around the trend caused by temperature variations is about 4 ppmv/°C. Thus worst case, the increase in temperature since the LIA (maximum 1°C), can have increased CO2 levels with 8 ppmv. That is all. The rest of the 100+ ppmv increase is from human emissions.
1.c. Plants use more CO2 when it is available. But not 100% more with a doubling of CO2. Extra growth is mainly between 20-80%, average 50%. The same for the oceans, where diffusion speed is very low and most absorption and release is thanks to wind stirring. That means that any extra CO2 above the (temperature mandated) equilibrium resides rather long in the atmosphere (~ 40 years half life time).
1.d. The direct effect of temperature is small: 16 ppmv/°C, but as vegetation acts in countercurrent, the real global effect is only 4-8 ppmv/°C. If temperature was the cause, the pH of the oceans would increase, not decrease, as CO2 escapes and relative more Ca en Mg ions stay in solution. Total inorganic carbon content (DIC) would decrease. But we see exactly the opposite: pH lowers and DIC increases. See:
http://www.bios.edu/Labs/co2lab/research/IntDecVar_OCC.html
1.e. Human emissions are responsible for near all of the increase of CO2 in the atmosphere.
1.f. Simply not true, temperature has a minor role in the increase.
1.g. If you have a bottle with carbonated water and you close the bottle, at a certain moment the pressure of the CO2 in the air above the liquid will be in equilibrium with the pressure of CO2 in the water: as many molecules enter the water as molecules escape. No matter how much more CO2 still is in the water.
If you change the temperature of the bottle, so will change the pressure above the water, again until a new equilibrium is reached. Thus the difference in (partial) pressure between CO2 in seawater (and plant alveoles) and in the atmosphere determines the net direction that CO2 will flow and with what speed (besides wind mixing speed, sink/upwelling speed,…).
3. I haven’t much problems with that point, but my fear is that if you don’t accept that the extra CO2 (in mass, not in origin) in the atmosphere is from human emissions, while all observations do agree with that, you undermine the position of the sceptics where the “consensus” is far weaker: the effect of 30% more CO2 (or a CO2 doubling)… One can discuss that point to every degree (my view here is anyway less than the “consensus”, thus maybe a beneficial 1-1.5°C for a CO2 doubling). At that point, the models have been proven wrong…
Engelbeen, I begin with point 3, where you think that I “undermine the position of the sceptics”. It may come as a surprise to you that the skeptics do not have a consensus as the warmists have. So my statements are just looked at and evaluated on their merit. No more, no less. I hope though, that they will give them serious thought, because nature does not work the way we think.
Our face-off is becoming a bit messy, particularly for outsiders. I do not claim that the increase in CO2 in air does NOT come from human emissions, but I am skeptical about it, because, as I have shown, there are other explanations that are not considered by the mainstream. Your replies also clearly show that the science is not settled, and you didn’t read my points carefully enough. So here we go again.
Our main difference, I think is that you look too much at the reservoir concept of the atmosphere, like a bean counter considering the asset inside rather than the invisible flow (“black market”) which is quite significant but almost impossible to measure. You mentioned the word ‘residual’ which is exactly what we see, but not the process. You mention a residual half life time of 40 years. Well, true residuals are infinite. The point is that most CO2 rotates very quickly, inside the soil and inside the ocean, in a matter of weeks to one year. That is the main flow. Similarly the main CO2 flows are from land to ocean and back, with a residual in air. In other words, the air part is the insignificant part, as if it is just a boundary. Remember that so many scientific measurements are wrong because they are done on ecological boundaries (glaciers, sea ice, coastal thermometers, bristle cone pines, and many more). Boundaries always change, and because of their nature, by factors belonging to either or both habitats (more factors than thought).
1a. rethink that from the flow perspective. Your constant referral to pCO2 is not good because it is something very local and not very accurate, and again remember that boundary statement above? We need to look at the overall picture; not the boundaries.
1b. same as 1a.
1c. you didn’t read my point carefully. Growth measurements have been done in pots and otherwise over a short time, without allowing carbon enrichment of the soil. It is not representative of natural ecosystems. New research from satellite data show surprising sequestration by some natural ecosystems. Thus wait and see.
1d. again the bean counter approach as 1a. looking at the residual rather than the flow.
1e. quite a religious statement here. More doubt would grace you.
1f. as I have shown from the solubility of CO2 in water, temperature is a MAJOR factor. You can’t go around this with pCO2.
1g. the classroom experiment, but where is your buffering? Do you really think that while CO2 was over 4000ppm in air, the oceans were highly acidic (10 times or perhaps one pH unit)? Don’t poopoo ocean chemistry and biochemistry. This remains a huge area of massive doubt. And here too, none of our predictions and fears have come true.
I think the bottom line of our exchange is that we agree to disagree. For me the jury is still out, and I am neither swayed your way, nor my own way.
Floor Anthoni says:
July 18, 2011 at 10:54 pm
Our main difference, I think is that you look too much at the reservoir concept of the atmosphere
While I look at the atmosphere as a reservoir, what happens to the CO2 mass in the atmosphere is a matter of difference in flows: no matter how much CO2 is circulating back and forth between oceans and vegetation via the atmosphere, only the difference at the end of the year is important, not the height or variability of the (individual) flows, neither the amounts in the other reservoirs.
The individual flows are only roughly known (or even unknown), but the net result after a year is well known: a loss of 4 +/- 2 GtC out of the atmosphere for all natural flows together. Thus all natural CO2 flows out of the atmosphere together are larger than all natural CO2 inflows together. It is that simple…
Again…
1.a. The only driving force for CO2 to go out of the oceans or into the oceans is pCO2. Without a difference in pCO2 between the oceans surface and the atmosphere, there is simply no (net) CO2 flow between them.
Thus if the oceans warm up, the pCO2(aq) increases, more CO2 is released from the oceans and enters the atmosphere. That increases the pCO2 of the atmosphere until pCO2(aq) and pCO2(atm) are equal, at which point there is again no net flow. No matter how much CO2 resides in the oceans or the atmosphere.
For each ocean water temperature (and salinity, DIC,…) the pCO2(aq) curve is available. The curve says that for 1°C increase of the water, pCO2(aq) increases with 16 microatm. Thus an increase of ~16 ppmv in the atmosphere is sufficient to compensate for 1°C increase in seawater temperature. You don’t need to know any individual CO2 flow or any individual pressure difference over the oceans, only an additional 32 GtC in the atmosphere is sufficient to stop the (net) CO2 outgassing of the oceans. And as humans have added some 350+ GtC in the past 160 years, that is more than sufficient…
1.b. Here too pCO2 is important, not the flows (that is just a matter of time), neither the quantities in the (deep) oceans, as the good correlation between temperature (proxy) and CO2 levels over 800.000 years shows.
1.c. As already said, carbon sequestration by vegetation is measured nowadays by the oxygen balance: in the period 1900-2004 some 1.2 +/- 0.6 GtC/year. With 30% (200 GtC) more CO2 in the atmosphere. A rather meager result, even if it is 1/6th of the human emissions.
1.d. The physico-chemical result of an increase in ocean temperature is a pH increase and DIC decrease, but we observe the opposite, that means that more CO2 is going into the oceans than comes out. Thus the net flow is opposite to what you expect from the temperature increase.
1.e. After several years of discussion, I may be quite confident, as I never heard an alternative explanation for the increase of CO2 which doesn’t violate one or more observations, as 1.d. shows. If a theory fails the observations, the theory is rejected…
1.f. See 1.a.
1.g. At 4000 ppmv, the oceans contained far more Ca and Mg ions at that time, which means that the pH might have been not so far from today. But foramins have eaten away lots of CO2 and Mg and Ca as can be seen in the white cliffs of Dover and lots of chalk deposits all over the world where once was the seafloor… But I have no fear that fish or foramins or the Great Barrier Reef will die from “acid” oceans…
Engelbeen, I have reworked the missing oxygen experiment of Bender et al. and Battle et al. and found strong evidence supporting your claims. When evaluating the 1990s decade for which we know humans burnt 60GtC, equivalent to 30ppm CO2 and (+45%) 43ppm O2, against Bender’s 200 permeg O2, divided by 4.8 = 41 ppmv O2, it is reasonable to conclude that these two figures match and that the residual CO2 in air is caused by human burning of whatever. The residual part of 30 ppm CO2 is 17 ppm while the other 13 ppm has vanished. There is no other place for it to go, without affecting O2, than the sea. So the sea has been absorbing CO2 rather than expelling it, and for at least 60 years or longer. That it may have been precipitated by human burning, is not relevant.
So, yes you are right. It remains a mystery of course why the sea absorbs precisely 43% of human emissions, but something else may be more worrisome. For at least 10,000 years the sea has been expelling CO2 since last ice age ended, and now has stopped doing so. It suggests that we have now arrived at the end of the warm interglacial, about to enter the next ice age. With the sun doing a nap now, we may be on the cusp of a steep roller coaster ride, not into a Dalton or Maunder minimum but into a true next ice age.
Thanks for your comments.
Floor Anthoni – There is another possible explanation, which I think is actually correct: Absent MM CO2, the oceans would have been outgassing CO2, but MM CO2 has tipped the balance the other way.
Says nothing about where things go next – eg, a severe cooling period could quite possibly see all MM CO2 being absorbed for a while.
Floor Anthoni says:
July 21, 2011 at 2:37 pm
So, yes you are right.
That is what real science needs to be: weighting the evidence and adjusting or rejecting the theories if the observations don’t fit the theory… One can only hope that one day, the CAGW people will become true scientists again…
If we may take the ice core CO2 levels as real, then we are now some 100 ppmv over the temperature mandated equilibrium of CO2 level. The (weighted) average difference in pCO2 is not that large (some 7 microatm), but that is for the oceans mixed layer, which simply follows the atmospheric CO2 level. More important are the poles, where the waters sink into the deep, but with more CO2 now than in the past, as the ocean pCO2 at the THC sink place should be for near freezing water, but the atmospheric pCO2 increased with about 100 microatm. Thus more CO2 enters the deep in ratio with the increase in the atmosphere (the same may apply for increased CO2 in plant alveoles). Which may explain the fixed ratio vs. man made CO2…
I don’t have that fear for a new glacial period, but a new Dalton minimum may be coming, the sun is doing strange things nowadays…
Mike Jonas: I fully agree, and it is not impossible that the Keeling curve will reverse and CO2 ‘residence times’ go negative 😉
http://www.seafriends.org.nz/issues/global/climate4.htm#missing_oxygen