Controversial new climate change results
University of Bristol Press release issued 9 November 2009
New data show that the balance between the airborne and the absorbed fraction of carbon dioxide has stayed approximately constant since 1850, despite emissions of carbon dioxide having risen from about 2 billion tons a year in 1850 to 35 billion tons a year now.
This suggests that terrestrial ecosystems and the oceans have a much greater capacity to absorb CO2 than had been previously expected.
The results run contrary to a significant body of recent research which expects that the capacity of terrestrial ecosystems and the oceans to absorb CO2 should start to diminish as CO2 emissions increase, letting greenhouse gas levels skyrocket. Dr Wolfgang Knorr at the University of Bristol found that in fact the trend in the airborne fraction since 1850 has only been 0.7 ± 1.4% per decade, which is essentially zero.
The strength of the new study, published online in Geophysical Research Letters, is that it rests solely on measurements and statistical data, including historical records extracted from Antarctic ice, and does not rely on computations with complex climate models.
This work is extremely important for climate change policy, because emission targets to be negotiated at the United Nations Climate Change Conference in Copenhagen early next month have been based on projections that have a carbon free sink of already factored in. Some researchers have cautioned against this approach, pointing at evidence that suggests the sink has already started to decrease.
So is this good news for climate negotiations in Copenhagen? “Not necessarily”, says Knorr. “Like all studies of this kind, there are uncertainties in the data, so rather than relying on Nature to provide a free service, soaking up our waste carbon, we need to ascertain why the proportion being absorbed has not changed”.
Another result of the study is that emissions from deforestation might have been overestimated by between 18 and 75 per cent. This would agree with results published last week in Nature Geoscience by a team led by Guido van der Werf from VU University Amsterdam. They re-visited deforestation data and concluded that emissions have been overestimated by at least a factor of two.
###
Here is the abstract from GRL:
Several recent studies have highlighted the possibility that the oceans and terrestrial ecosystems have started losing part of their ability to sequester a large proportion of the anthropogenic CO2 emissions. This is an important claim, because so far only about 40% of those emissions have stayed in the atmosphere, which has prevented additional climate change.
This study re-examines the available atmospheric CO2 and emissions data including their uncertainties. It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero. The analysis further shows that the statistical model of a constant airborne fraction agrees best with the available data if emissions from land use change are scaled down to 82% or less of their original estimates. Despite the predictions of coupled climate-carbon cycle models, no trend in the airborne fraction can be found.
Knorr, W. (2009), Is the airborne fraction of anthropogenic CO2 emissions increasing?, Geophys. Res. Lett., 36, L21710, doi:10.1029/2009GL040613.
According to Pat Michaels at World Climate Report:
Dr. Knorr carefully analyzed the record of anthropogenic CO2 emissions, atmospheric CO2 concentrations, and anthropogenic land-use changes for the past 150 years. Keeping in mind the various sources of potential errors inherent in these data, he developed several different possible solutions to fitting a trend to the airborne fraction of anthropogenic carbon dioxide emissions. In all cases, he found no significant trend (at the 95% significance level) in airborne fraction since 1850.
(Note: It is not that the total atmospheric burden of CO2 has not been increasing over time, but that of the total CO2 released into the atmosphere each year by human activities, about 45% remains in the atmosphere while the other 55% is taken up by various natural processes—and these percentages have not changed during the past 150 years)
Here is Figure 1 from the Knorr paper:
Figure 1. The annual increase in atmospheric CO2 (as determined from ice cores, thin dotted lines, and direct measurements, thin black line) has remained constantly proportional to the annual amount of CO2 released by human activities (thick black line). The proportion is about 46% (thick dotted line). (Figure source: Knorr, 2009)
The conclusion of the Knorr paper reads:
Given the importance of the [the anthropogenic CO2 airborne fraction] for the degree of future climate change, the question is how to best predict its future course. One pre-requisite is that we gain a thorough understand of why it has stayed approximately constant in the past, another that we improve our ability to detect if and when it changes. The most urgent need seems to exist for more accurate estimates of land use emissions.
Another possible approach is to add more data through the combination of many detailed regional studies such as the ones by Schuster and Watson (2007) and Le Quéré et al. (2007), or using process based models combined with data assimilation approaches (Rayner et al., 2005). If process models are used, however, they need to be carefully constructed in order to answer the question of why the AF has remained constant and not shown more pronounced decadal-scale fluctuations or a stronger secular trend.
Michaels adds:
In other words, like we have repeated over and over, if the models can’t replicate the past (for the right reasons), they can’t be relied on for producing accurate future projections. And as things now stand, the earth is responding to anthropogenic CO2 emissions in a different (and perhaps better) manner than we thought that it would.
Yet here we are, on the brink of economy crippling legislation to tackle a problem we don’t fully understand and the science is most certainly not settled on.
UPDATE: A professional email list I’m on is circulating the paper, read it here: Knorr 2009_CO2_sequestration
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Smokey (10:26:53) :
carrot eater,
After following your numerous posts, I am still waiting for your answer to this question: will an increase in CO2 cause a “tipping point” to be reached, where runaway global warming and climate catastrophe result?
Can we not get the carbon cycle sorted out first.
I can’t speak for carrot eater, but I’m fairly sure Ferdinand Engelbeen cannot be described as a “climate alarmist” and I’m what you might call a ‘lukewarmer’. The point is I don’t think any of us is trying to say anything about global warming on this thread. I think we all agree, though, that human CO2 emissions are mainly – if not solely – responsible for the increase in atmospheric CO2 concentrations over the past ~100 years.
There is no other plausible explanation for the steady sustained increase which has been observed. The Knorr paper doesn’t dispute this. It simply notes that there has been an increase in absorption by the oceans and biosphere which has partially ‘offset’ the increase from human emissions.
In the context of this discussion it doesn’t matter what the ‘new’ source of the emissions is. The new source is currently adding ~4 ppm/yr – but the earth is responding by removing ~2 ppm. (these are very, very approximate numbers).
Ferdinand, a couple of thoughts:
First, Freeman Dyson covers part of this subject: click. [Scroll down to #2: Climate and Land Management.]
Dyson shows that biological activity responds to higher CO2 levels. In addition, the U.S. alone has increased its forest cover by about 40% over the past century, and that number is still rising. Trees grow slowly, so there is a lag time between rising CO2 and sequestering by plants.
Next, you say that many of the current CO2 measurements have still have very large margins of error. But Beck’s reconstruction is also based on numerous CO2 measurements made last century, many done by Nobel laureates on isolated sea coasts, on mountains, and during ocean crossings, all with a tolerance [IIRC] of about ±3%. Those measurements were nothing like the iconic Mauna Loa CO2 graph we see everywhere, which shows a very steady rise, which is nothing like the readings taken from tall towers.
I know you have a problem with Beck’s extensive work, but even these current CO2 readings in different locations do not agree. Furthermore, Beck’s reports of CO2 readings are not “adjusted” like NOAA’s: [click – this is a blink gif, give it a few seconds to load].
Who to believe? Those providing raw data? Or data that has been adjusted?
Ferdinand,
CO2 doesn’t have to go through an organic cycle to precipitate as CACO3. Sea water saturated with CO2 (upwelling) will precipitate CaCO3 when the temperature is raised. Of course raising the temperature increases the partial pressure of both water and CO2.
carrot eater (11:17:05),
Thank you for your views [but this wasn’t a tangent from the topic, which specifically concerns anthropogenic CO2].
The mind-set that Stern and the IPCC exhibit throughout their reports generally exclude the indisputable benefits of a slightly warmer climate. Only people and organizations with an agenda would so casually dismiss the benefits of additional warmth [although they do throw in the obligatory comment]. When scientists on both sides of the issue cooperate in writing those reports, rather than the reports being written political appointees whose livelihood depends on taking the position that their superiors demand, then they will get the credibility and respect they desire.
Anyway, thank you for responding. [And don’t eat too many of those carrots, or you’ll look like this.]
P Wilson (08:00:55) :
simply because you have to separate the fluxes of natural from anthropogenic, natural being mainly sea exchanges, where seas contain 1000gt at the surface. It seems natural to me that we cannot measure how much c02 air exchanges with oceans according to se surface temperatures, although when its warmer, oceans exhale more. We’re at another relatively high SST at the moment, which means oceans expel more than they absorb, and this increases that carbon cycle. The best we can say is that if nature is responsible for 97% of aerial c02 then we’re responsible for 3%.
You still don’t get it. It doesn’t matter what the source of the remaining CO2 in the atmosphere is. Even if all human emissions were absorbed in the next trees within a minute, the same trees would have used natural CO2 instead. Thus even if the atmosphere is 100% composed of natural CO2 after one minute, the total amount of CO2 in the atmosphere did increase, because you added CO2 to a system where the natural balance was (more or less) in equilibrium. Thus while not one molecule of aCO2 is left, the increase is fully the result of the addition of aCO2.
And in the past 60 years, the oceans were never a net source (over a year) of CO2, always a net sink. Temperature only modulated the sink capacity of the oceans (and vegetation after 1990, before that vegetation was a small source). See: http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em.jpg
i don’t accept that total emissions were fixed before 1850. There are some remarkable spikes and slumps prior to 1840 at decadal and centennial timescales – proxies from stomata during the MWP suggest 400+ppm. so if we take the pre industrial to be
antarctic Ice, which has up to 6,000, or a corrected 4,000 years difference between its ice formation and its c02 capture at a subzero environment then they show more flux than a fixed in/out quantity.
other proxies from Greenland show greater varieties
I have had several discussions with stomata specialists. These have a their own problems. For the 20th century they are calibrated against… ice cores. But the main problem is that stomata data are based on land (by definition!): any local/regional land change (marshes to forests to pasture to agriculture) in the main wind direction influences local/regional CO2 levels, which makes the method not very reliable, if no detailed knowledge of these changes and their influence on CO2 levels/stomata data is available.
BTW, the 20th century stomata data refute the 1942 peak of CO2 found in the historical data of Beck…
The ice cores of Greenland are interesting for temperature history, but not reliable for CO2 measurements, due to the frequent inclusion of volcanic dust (from Iceland), which may produce CO2 in situ. The Antarctic ice cores with the best resolution have only a lag of 30 years and a 8 years resolution down to 1850. The next best have a 30 years resolution (and show a small CO2 dip during the LIA) with a 80 years lag. Thus good enough to detect any peak of 100 ppmv over a period of 10 years or more.
And there are other proxies which confirm the addition of human CO2: coralline sponges give a direct d13C level of seawater, quite stable (just some small wiggles due to temperature swings) until about 1800, then a steeper and steeper drop:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif
If the (deep) oceans were the main source of CO2, the d13C levels would increase, but we see a sharp decrease.
Smokey: Well, if we’re talking about some physical point, I think it’s best to keep politics and economics aside during that discussion. Anyway, thank you for graciously inviting and hearing my views, seeing as this isn’t exactly home turf for me.
As for Mauna Loa: the raw data is available for anybody to look at. Every single data point that is rejected is labeled with the reason for which it was rejected. Those reasons seem quite reasonable to me. Even if you leave the rejected points in there, the picture doesn’t really change.
C13 levels have been increasing but C12 a little faster. C12 also comes from the oceans from the decomposition of organic matter (and naturally from land from the same process). In a mature forest, on an annual basis, as much CO2 is emitted as is consumed.
Smokey (11:33:59) :
Dyson is right, but doesn’t quantify biogenic growth. From the oxygen balance we know that the whole biosphere (vegetation + soils + marine) is good for an uptake of 1.4 +/- 0.8 GtC/year, that offsets a lot of CO2 from the (then) 7 GtC human emissions, but not everything.
You need to make a differentiation between “background” CO2 levels and CO2 levels measured near (huge) sources and sinks. If you measure over land in the middle of towns or in a forest, a rice field,… you will see that day and night gives enormous changes (hundreds of ppmv within hours). If you measure over the oceans or high on a mountain or in the middle of a desert, or in a plane over 500-1,000 m, you will see little diurnal variation and the same value all over the world, with some seasonal variation (in the NH) and a NH-SH lag. Thus in 95% of the atmosphere, you see the similar CO2 levels. Only in 5% of the atmosphere, the first few hundred meters over land, you can find any CO2 value you (don’t) wish. Therefore the tall tower data (and other land based data) are not used for global averaging, as a few stations (10 “baseline” stations around the poles and in the Pacific) are sufficient to describe the CO2 content and trends for 95% of the atmosphere. But the land based stations are of interest for flux measurement and attribution.
The historical measurements taken at coastal areas (with wind from the sea), on mountain tops (Ben Nevis, Scotland), on seaships are around the ice core levels. That is the reason that Callendar with stringent a priory selection criteria did find lower average values of CO2, which were confirmed 60 years later by the ice cores…
The graph + correction from Mauna Loa you have sent was extensively discussed here on WUWT ( see
http://wattsupwiththat.com/2008/08/06/post-mortem-on-the-mauna-loa-co2-data-eruption/ )
with an valid explanation by Pieter Tans: due to a computer failure, they had only 10 days of data at the end of the month. As that was the month with the largest change of CO2 level, the plotting of the average at the 15th of the month did skew the trend. This was adjusted by an algorithm that used the average shape of the previous years, same months, to correct the graph.
As said already by carrot eater, the raw data are available for inspection (I even asked for the raw voltage data used to calculate the raw hourly CO2 averages and received them) at:
ftp://ftp.cmdl.noaa.gov/ccg/co2/in-situ/mlo/
All procedures used for calibration and selection are clearly explained here: http://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html
And the selection of all data or deselection of outliers doesn’t make any difference for the averages or trend, see:
http://www.ferdinand-engelbeen.be/klimaat/co2_measurements.html#Variations_due_to_local_circumstances:
Even after preselection, their still are 150 valid samples per day left.
In contrast, we have little idea about the calibration procedures, the accuracy of the methods, the accuracy of the chemicals used, the skill of the people in sampling and measuring the historical data.
In one of the longest series, Giessen in Germany 1939-1940, three samples per day were measured, of which two were taken at the moment of highest diurnal change (often 150 ppmv day-night). Guess what happens if the sample was taken 15 minutes later or earlier…
And are you sure that Beck’s data aren’t changed? I read some strange sentences in his Excel sheet:
“Korrigiert um -15ppm” (Corrected with -15 ppm)
“Korrigiert um +9ppm wegen Sommer” (Corrected with +9ppm because of summer)
“Wert interpoliert” (Value interpolated)
Anyway, Beck used data from places which were completely unsuitable for background CO2 level measurements, as if all data were of the same good quality…
Ferdinand Engelbeen (12:03:41) :
I’m asking if Antarctic ice cores are the golden standard for pre industrial atmospheric c02.
If the IPCC says “since1961 show that the average
temperature of the global ocean has increased to depths
of at least 3000 m and that the ocean has been absorbing
more than 80% of the heat added to the climate system.”
and
“According to Takahashi (1961) heating of sea water by 1 degree C will increase the partial pressure of atmospheric CO2by 12.5 ppmv during upwelling of deep water. For example 12 degrees C warming of the Benguela Current should increase the atmospheric CO2 concentration by 150 ppmv.”
(segalstad)
it seems logical that given we’re at the high point of an interglacial oceans are outgassing c02 more than they are absorbing them
http://www.eea.europa.eu/themes/coast_sea/sea-surface-temperature
puts the SST at 1C higher than 140 years ago, although since its accepted or known that the sun has *reputedly* been more active during the 20th C than at any time in its history then that suggests a mainly natural increase in c02. *reputedly* a la Henry’s law, a 0.1C increase in SST’s leads to 6GT of c02 release, whilst at 30metres, a 1C temperature increase leads to a 600GT (nearly all c02 in the atmosphere) release of c02. Of course this c02 doesn’t accumulate in the atmosphere, as its always in transition, although it seems to me that when c02 is dissolved in ocean, it sinks or downwells, leaving less immediate c02 to be expelled during warmer ocean periods again for hundreds of years AC02 included. However, whilst anthropogenic c02 is a straight increase, that of natural flux isn’t, as it goes up and down, so if anthropogenic is a fixed fraction, whislt natural variation isn’t, then it still looks like oceans/SST’s regulate the amount of c02, and nearly everything else in the climate, in the atmosphere in the last analysis.
P Wilson (18:19:19) :
As repeatedly said by carrot eater and me, Henry’s Law is perfect for fresh water. It doesn’t hold that easely for seawater, because even if the first term (the temperature) applies, the CO2 pressure in the water phase is a complex reaction on temperature, pH, salts content, DIC content and the biological activity which influences all the previous ones. Without a pressure difference between CO2 in solution and CO2 in the atmosphere, no transfer at all. If algue show an extra bloom, CO2 can be sucked in, even when the temperature is much higher than before.
But in general, with higher seawater temperatures, more CO2 will be released in the tropics at the upwelling places and less absorbed at the sink places. That will increase the CO2 levels in the atmosphere, until the increased pressure reduces the outgassing at the tropics and augment the absorption at the poles enough to establish a new equilibrium (at a higher CO2 level).
And don’t forget that the biosphere on land also works counter the temperature increase of the oceans, which helps to reduce the temperature effect on CO2 levels…
From the (far) past we know that over many millennia, the equilibrium shift is about 8 ppmv/°C. This also holds for the 1°C change from the MWP to the LIA and thus probably for the warming since the LIA until now. Thus at maximum 8 ppmv increase is due to ocean and land warming.
If you don’t trust the ice core data, the current influence of temperature on CO2 variability around the trend is about 4 ppmv/°C, thus even less for a 1°C change, but that is a short-term reaction (1-3 years), the long-term 8 ppmv/°C anyway is not far off.
Further, human emissions are increasing, thus no fixed fraction, while natural (mainly temperature induced) variability (the inflows minus outflows) is +/-1 ppmv around the trend, thus only halve the current emissions.
Fred H. Haynie (11:50:33) :
CO2 doesn’t have to go through an organic cycle to precipitate as CACO3. Sea water saturated with CO2 (upwelling) will precipitate CaCO3 when the temperature is raised. Of course raising the temperature increases the partial pressure of both water and CO2.
At the current CO2 levels we have a mixture of bicarbonate and carbonate in seawater. One need to loose a lot of CO2 before carbonate would drop out. It happens at very elevated temperatures in boilers etc., but I have not the impression that it happens in seawater without biological help. The reverse may happen if CO2 levels increase and start to dissolve carbonates into bicarbonate.
C13 levels have been increasing but C12 a little faster. C12 also comes from the oceans from the decomposition of organic matter (and naturally from land from the same process). In a mature forest, on an annual basis, as much CO2 is emitted as is consumed
Oceans degassing and absorption did set the initial levels of the 13C/12C ratio, due to fractionation in both directions. That was with 0-4 per mil d13C in (deep to surface) seawater some -6 per mil in the atmosphere. Today we are at -8 per mil (see the coralline sponges chart at:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif ). If the oceans would be the main source of the increase in CO2 content of the atmosphere, the d13C levels would increase, not decrease as we see nowadays.
The biosphere (including marine plants) may enrich or deplete 12C levels in the atmosphere, depending what is winning: plant decay vs. plant growth. As more oxygen is produced than used by the biosphere, plant growth wins, thus depleting 12C more than 13C, thus increasing the 13C/12C ratio, while we measure a decrease.
Thus neither the oceans, nor the biosphere (soil+land vegetation+marine vegetation) can be responsible for the decrease in 13C/12 ratio and thus are not the main cause of the increase of CO2 in the atmosphere…
Ferdinand Engelbeen (02:21:08)
Henry’s law still applies though at a different coefficient, ie not at the ideal constant which works best for fizzy drinks, though it should really be called Henry’s coefficient than a constant, and its on the basis of this coefficient that the above results are obtained.
Takahashi, T; Sutherland, SC; Sweeney, C; Poisson, A; Metzl, N; Tilbrook, B; Bates, N; Wanninkhof, R; Feely, RA; Sabine, C; Olafsson, J; Nojiri, Y “Global sea-air CO2 flux based on climatological surface ocean pCO2 and seasonal biological and temperature effects” Deep-Sea Research (Part II, Topical Studies in Oceanography) [Deep-Sea Research (II Top. Stud. Oceanogr.)] 49, 9-10, pp. 1601-1622, 2002
P Wilson (04:00:25) :
From the abstract of Takahashi e.a. ( http://tinyurl.com/ybanntb ):
Thus in some cases temperature wins, in other cases its biology which wins. No straight-forward application of Henry’s law is possible…
See also the delta-pCO2 map of Feely e.a.:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/images/fig03.jpg
where you can see that the North Pacific is a source of CO2 in winter and a sink in summer. The North Atlantic is a stronger sink in summer than in winter. Opposite to the seawater temperature…
Ferdinand: “From the (far) past we know that over many millennia, the equilibrium shift is about 8 ppmv/°C.”
This is where I dislike your wording, and it comes back to your statement here:
“dT = Te – Tb, the difference in temperature between start and end of the period, whatever length of period. For short periods (0-2 years) the factor 4 ppmv/K applies, for periods longer than a few centuries (to near a million years), the factor 8 ppmv/K applies. For in between periods, no reliable data are available, but I suppose that the factor would be in between.”
You are using the same term to describe entirely unrelated physical processes. The short term action is just helping to fit short-term variability in the atmsopheric uptake rate, related to volcanic effects and El Nino. I don’t entirely understand why the uptake rate is dependent on these factors, but there it is.
The long term action is not a matter of variability in uptake rate. It’s simply reflecting a net outgassing from the oceans, due to rising temperature. Exactly why the oceans were outgassing like that is not entirely clear (though there are good ideas), but they currently aren’t doing anything like it (the oceans are still a net sink, currently).
P Wilson:
Look at this diagram:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/images/fig01.jpg
(taken from here:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/feel2331.shtml)
Henry’s Law only tells you about the relation between CO2(g) and CO2(aq), if they were at equilibrium. That they aren’t at equilibrium is what drives net flux into or out of the ocean, depending on where on earth you are. But you’ll notice that there’s also all sorts of other chemistry that affects CO2(aq): see how little of the CO2 actually exists as CO2(aq) in the liquid phase. On top of that, there is uptake by living things (sadly, not shown in the figure). Beyond that, the ocean is somewhat stratified, so there is poor mixing with the deep ocean.
So Henry’s Law is useful, but you need to consider many other things as well to understand ocean-air CO2 fluxes.
Ferdinanad and Carrot Eater. I’m not disputing these principles, and understand oceans are complex, and warm and cool at the same time depending on location. Its a huge system that must be complex to document as to whether it is a net sink or a net source at the moment, given that SST’s and OHC are elevated on average for the last 150 years.
I’m just trying to ascertain, without and direct measurements – the sort that are taken without inference from other measurements – why the Anthropogenic fraction of aerial c02 remains the same now as it did since 1850. In todays terms that would be 3-4% of today’s total.
P Wilson:
“why the Anthropogenic fraction of aerial c02 remains the same now as it did since 1850. ”
That isn’t even close to what the paper says.
The paper says this: if I put 1 ton of CO2 into the air tomorrow by burning some coal, then after things cycle around, the atmosphere will have 0.45 more tons of CO2 in it, and the oceans and biosphere will have 0.55 more tons of CO2 in them. These fractions vary from year to year, but there’s no trend in that fraction, either up or down.
Please stop trying to label individual molecules as being anthropogenic or natural. It is not a meaningful exercise for the purposes of this discussion.
The pre-industrial atmospheric concentration was what, 280 ppm or so? It is now 385 ppm. That rise is due to human activities. The rise would have been higher, had the airborne fraction described by the paper been also rising.
carrot eater (07:17:07) :
You are using the same term to describe entirely unrelated physical processes. The short term action is just helping to fit short-term variability in the atmsopheric uptake rate, related to volcanic effects and El Nino. I don’t entirely understand why the uptake rate is dependent on these factors, but there it is.
In my opinion, the short term temperature dependency and the long term are of the same origin. In both cases (Pinatubo and El Niño), there is a quite good correlation with (sea surface) temperature, although the origin of the temperature variation was different.
There are two main forces at work with increasing(/decreasing) temperatures: more CO2 release(uptake) by the oceans and more uptake(/release) by (marine and land) vegetation. These counteract each other to a certain extent. Marine organisms drop off CO2 as carbonate (and organic carbon) to a certain level, probably in ratio to growth, and land plants bury in part CO2 in more sustainable carbon deposits and are influenced by (temperature induced) precipitation.
The short time ratio of 4 ppmv/K is the reaction found on the detrended curve for the past 60 years and is surprisingly linear. See:
http://icecap.us/images/uploads/CO2vsTMacRae.pdf (but I don’t endorse his conclusions!)
The trend itself is independent of temperature and the result of human emissions, besides a small increase due to the warming in the past century. That makes that the oceans are a net sink for CO2, but that seems not to change the amplitude of the temperature influence (neither over the seasons nor from year by year temperature variations).
Over longer periods, some additional long term changes add to the equation: the vegetation covered land/landice ratio changes, less/more ice cover of the polar oceans, changing ocean currents,… But again the ratio is surprisingly linear.
Thus it looks that the same base mechanism(s) are at work which keep the ratio temperature change / CO2 change quite linear, but with an extended factor over longer term, due to more time consuming reactions influencing the ratio.
Sorry if I am not always clear, English is not my native language, and I have a habit to jump too fast towards conclusions, without explaining all the underlying thoughts which led to that conclusion…
Ferdinand:
First, no need to apologise, especially about language. Your English is infinitely better than my Flemish (assuming that’s what you speak).
In order to give your last response a fitting reply, I would have to study the literature about the variability of atmospheric uptake with ENSO, volcanoes or temperature. I haven’t time for that now, so I’ll have to let it pass for now.
By the way, did you know that one Ian Plimer published a book, and appeared to have used some analysis on your website? So maybe you have some influence and an audience. Sadly, he used only part of the analysis, and so reached the exact opposite conclusions. This was discussed elsewhere; if you are curious.
Food for thought:
Co2 at Pt Barrow is increasing at approx 1.6ppm/year
The annual CO2 suck out is increasing in depth by only .17ppm/year
http://img4.imageshack.us/img4/4449/co2dipptbarrow.jpg
So CO2 is increasing 10 times faster than the suck is increasing. Assuming the suck is flora / fauna utilising CO2 then releasing it on die-back, then the flora fauna is in no way compensating for the increased CO2.
A question why is the suck in march just about equal to the CO2 blow in August? Shouldn’t some be retained by groth in the plants etc?
carrot eater (16:08:28) :
The paper called “Is the airborne anthropogenic emission of c02 increasing?” says that the fraction of aerial c02 against the fraction of absorbed c02 has remained constant since 1850.
“Dr. Knorr carefully analyzed the record of anthropogenic CO2 emissions, atmospheric CO2 concentrations, and anthropogenic land-use changes for the past 150 years. Keeping in mind the various sources of potential errors inherent in these data, he developed several different possible solutions to fitting a trend to the airborne fraction of anthropogenic carbon dioxide emissions. In all cases, he found no significant trend (at the 95% significance level) in airborne fraction since 1850”
Given that aerial c02 is 30% higher than what is recorded in ancient ice, this 30% has accumulated in the atmosphere, according to the present notion that warns of catastrophic climate change, because of fossil fuel emissions and other human activities. Knorr maintains 45% anthropogenic c02 staying in the atmosphere. 45% today represents about 2% of total aerial c02. this total fraction hasn’t changed since 1850, so it follows that the 30% increase in aerial c02 since 1850 isn’t anthropogenic. It also suggests that absorbed anthropogenic emissions are constant to their fraction of emission since 1850.
It raises several possibilities, based on the observation that this fraction is stable, and given the premise that absorbtion doesn’t distinguish between natural and anthropogenic c02:
1) We are at a natural high point of c02
2) there is an unknown source of c02 (unless it is oceans)
3) Antarctic ice cores don’t record the full amplitude of pre industrial c02 which could have been 360-400ppm
4) c02 exchanges are not fixed at a set quantity by nature and don’t follow a flowchart of presently agreed finite magnitudes.
5) Oceans and land both emit and absorb far more c02 than current thinking measures
P Wilson:
“Given that aerial c02 is 30% higher than what is recorded in ancient ice, this 30% has accumulated in the atmosphere …. because of fossil fuel emissions and other human activities.”
Yes. A 30-40% increase from preindustrial levels due to man; about 30% of what’s there is due to man.
“Knorr maintains 45% anthropogenic c02 staying in the atmosphere.”
Yes. If X tons are emitted by man per year, than 0.45X tons/year will accumulate in the atmosphere.
“45% today represents about 2% of total aerial c02.”
What? I have no idea what you are trying to say here. No, taking 45% of human emissions over time, you end up at the current 385 ppm, instead of the 280 ppm you started with. The same 30% increase due to man you just started with. What is this 2%?
“so it follows that the 30% increase in aerial c02 since 1850 isn’t anthropogenic.”
It follows how? I really don’t know what to tell you. You are somehow not understanding what the 45% is referring to, but I can’t figure out how.
going by the study. this percentage fraction shows no increase since 1850 – meaning that if aerial anthropogenic c02 is 2% this year it was 2% , last year, tracing back to 1850 when it was less than 2%. This aerial fraction doesn’t accumulate to 30% but remains constant at 2%, whislt natural c02 in the atmosphere follows the same process at a constant of its fraction, as year on year, the absorbtion process continues. In other words, 30% anthropogenic doesn’t accumulate over 150 years whilst natural c02 shrinks to 70% as a proportion of aerial co2, as if half of AC02 is absorbed one year, next year half will be absorbed, which never takes it it more than 3% of the total – every previous years c02 gets absorbed also in addition to every current year’s emission. It doesn’t mean 2% (4%/2) accumulates in the atmosphere incrementally, but that for some reason, it remains constant at 2%, since the 2% atmospheric from TWO, THREE, years and working backwards prior also gets absorbed. at some stage, presuming that nature doesn’t dinstinguish between natural and anthropogenic c02
‘Previous studies suggested that in the next ten years the amount of CO2 in the atmosphere will accelerate because there is a lot less uptake by the Earth, there is no indication of this,’ he said. (Dr Wolfgang Knorr).
so given the results thereof, all I can suggest is the 5 points.
“45% today represents about 2% of total aerial c02.”
sorry I wasn’t so clear. 45% AC02 (the other 55% absorbed) represents 2% of all aerial c02
P Wilson (17:56:52) :
Knorr maintains 45% anthropogenic c02 staying in the atmosphere. 45% today represents about 2% of total aerial c02. this total fraction hasn’t changed since 1850, so it follows that the 30% increase in aerial c02 since 1850 isn’t anthropogenic. It also suggests that absorbed anthropogenic emissions are constant to their fraction of emission since 1850.
You are still confusing what happens with the mass of CO2 added to the atmosphere and what happens with the individual molecules which are added.
Of the total mass in CO2 added by humans last year, about 45% remains in the atmosphere. Since last year all human induced CO2 is red coloured (to show the difference). As that is 45% of 10 GtC, some 4.5 GtC (2.2 ppmv) are added to the atmosphere, which contained 800 GtC, thus at the end of last year, the total mass in the atmosphere increased to 804.5 GtC, of which 4.5/804.5 = 0.6% is red colored and thus of human origin.
I hope we can agree here that in the above scheme, the fraction of human induced CO2 is very small (0.6%) at the end of the year, but that the increase in total CO2 is 100% caused by the amount of human CO2 which was added.
This year, we add again 10 GtC as red colored CO2. Of this 10GtC, again about 4.5 GtC remains in the atmosphere at the end of the year, thus the total amount of CO2 in the atmosphere increases to 809 GtC, of which 0.6% was added with a red colour. But anyway, the full 9 GtC increase from last year and this year together is 100% caused by the human addition.
Of the 0.6% red coloured CO2 of last year some 20% is exchanged by the seasonal CO2 exchanges (which removes CO2 regardless of colour, but only add colourless CO2 from nature) mainly with the oceans. That means that about 0.5% of last year’s red CO2 still is in the atmosphere + 0.6% of this year, thus about 1.1% of the atmospheric CO2 now is red colored.
And so on for all previous and following years. Over time the fraction of red coloured CO2 increases to about 6%, but still the full increase in total mass is due to the year by year addition of red coloured CO2.
So you are right that the fraction of human CO2 remaining in the atmosphere is quite small, but that is irrelevant for what happens with the total amount of CO2 as mass, where (near) 100% of the increase is from human emissions.