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.
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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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carrot eater (07:32:17)
Le Quéré (an empirical work, not modeling) only found hints of a weakened ocean sink in the Southern ocean (not the total global sink) over the last few years.
But it is incorrect, in as far as there seems to be an asymmetric resilience with the biological pump, eg Marinov et al 2006
: Modelling studies have demonstrated that the nutrient and
carbon cycles in the Southern Ocean play a central role in setting
the air–sea balance of CO2 and global biological production1–8.
Box model studies1–4 first pointed out that an increase in nutrient
utilization in the high latitudes results in a strong decrease in the
atmospheric carbon dioxide partial pressure (pCO2 ). This early
research led to two important ideas: high latitude regions are
more important in determining atmospheric pCO2 than low
latitudes, despite their much smaller area, and nutrient utilization
and atmospheric pCO2 are tightly linked. Subsequent general
circulation model simulations show that the Southern Ocean is
the most important high latitude region in controlling preindustrial
atmospheric CO2 because it serves as a lid to a larger
volume of the deep ocean5,6. Other studies point out the crucial
role of the Southern Ocean in the uptake and storage of anthropogenic
carbon dioxide7 and in controlling global biological
production8. Here we probe the system to determine whether
certain regions of the Southern Ocean are more critical than
others for air–sea CO2 balance and the biological export production,
by increasing surface nutrient drawdown in an ocean
general circulation model. We demonstrate that atmospheric
CO2 and global biological export production are controlled by
different regions of the Southern Ocean. The air–sea balance of
carbon dioxide is controlled mainly by the biological pump and
circulation in the Antarctic deep-water formation region,
whereas global export production is controlled mainly by the
biological pump and circulation in the Subantarctic intermediate
and mode water formation region. The existence of this biogeochemical
divide separating the Antarctic from the Subantarctic
suggests that it may be possible for climate change or human
intervention to modify one of these without greatly altering the
other.
Anthropogenic CO2 emissions are no more than 8 billion, some say 6 billion tons per year. Even if we accept the larger of the two numbers it is only 4.1 ppm per year.
When you look at the some of the other sources of natural production and compare these numbers to our output it puts our emissions into perspective.
Then if you consider that these natural sources can vary up or down in one day by more than ten times what we are able to produce in a whole year you get even more perspective.http://www.spinonthat.com/CO2.html
Don’t know if this question was answered already, but I’ll take a shot, maybe someone can correct where I go wrong? Then Tim and I will both learn something. 🙂
“Isn’t the simple fact that CO2 ppm is rising enough?”, Tim asks.
Well, no. The doomsayers predict that we are going to face….doooooommmm! Why? Because nature has had as much CO2 as it can handle. This study says that nature is still eating the same amount of CO2 that it has been, and so, the ppm (parts per million in the atmosphere) of CO2 will continue to rise at the same rate, instead of faster.
DDDOOOOOMMMMM!!!!!
Ok, sorry, I really liked that Fed-Ex commercial.
Do I have the basic points right here?
Extra nutrients in Southern Ocean take up CO2?
Actually more cold water in southern high latitudes than northern so more CO2 dissolves. Y’know, colder beer is fizzier.
Ferdinand Engelbeen (00:08:18) :
Thanks so much for the link.
As a young engineer I had measured many different systems. What
I have found over time, is that an increase in one element of an open
system, rarely results in a linear increase of that element. In other
words, atmospheric CO2 increases are too linear. I don’t trust them.
In the now infamous words of a former senator, “It requires the
willing suspension of disbelief.” So, like a salmon, I return to this site,
(WUWT), not because of the insightful postings of some of the most
brilliant scientists and engineers; but because I must.
http://climaterealists.com/forum/viewtopic.php?f=2&t=125
Politics and money and false markets.
Fred H. Haynie (09:35:18) :
Exactly. That fudge factor is used by the IPCC to alarm everyone. But most, if not all peer reviewed papers debunk the IPCC’s claim of long CO2 residence times: [click]
The UN/IPCC’s political appointees are forced to argue long CO2 residence times, because if CO2 only remains in the atmosphere for ten years or so the entire CAGW claim falls apart.
The biosphere craves more CO2, and it will use all we can give it.
Richard111 (00:05:47) :
Google algal blooms. Seems to be an unprecedented rise in ocean algae blooms causing havoc to bird life. I am not a scientist, but I don’t think algae and ocean acid can exist at the same time.
That’s reverse logic. If you’re hypothesis is increasing CO2 causes algae bloom, then CO2 is beneficially increasing algae in spite of alledged acidification. Your concern should then be the positive or negative consequences of more algae blooms. I don’t know if they are causing havoc to bird life.
Chris Schoneveld (23:08:38) :
I am confused. If the proportion of manmade CO2 remains the same while the total amount of CO2 is rising steadily doesn’t this mean that at the same time natural CO2 must be rising as well to keep that proportion stable? What is then the source of that extra natural CO2?
Anne van der Bom (06:07:49) :
In nature most plants do not have the luxury of being pampered in this way. Whether or not a plant will grow faster due to more CO2 depends on whether there are other factors that form a constraint.
Ferdinand Engelbeen (06:11:35) :
Thus indeed in general there is more growth, but not 100% more growth for a 100% higher CO2 concentration. The more that CO2 is not the only restricting item in nature: lack of light, low temperatures, lack of sufficient amounts of minerals/fertiliser or water may be limiting growth despite increased CO2 levels…
1. Someone stated that 45% of anthropogenic CO2 releases remain in the atsmosphere. I believe the poster confused isotopic analysis with absolute quantity, as the US Department of Energy analysis determined that only 4% of the increased Anthr.. releases remained in the atsmosphere causing the increase to ~ 380 ppm. Therefore, Chris, increasing Anthro.. [pCO2] induces increased plant (or ocean organism) growth, period. But increasing plant growth and subsequent decay returns increased amounts of CO2 back into the atsmosphere. The sequestration of the 96% of mans’ releases is either captured in urban structures, oceanic cycles, long-lived species (trees, shrubs) or in increases in soil organic matter (which is increasing). How much in each is debated, but a .05% increase in carbon sequestered in the soil could account for all of it. Increased soil organic matter also leads to imcreased biomass (sequestration) as numerous beneficial processes are correlated to OM, ie. nutrient availability, water infiltration and retention, reduction in compacted soil root impedance, etc. IMHO, the significance of this study is humans increasing CO2 contributions are still being sequestered at the same proportionate rate. Logically then, more is being sequestered each year. Plant response indicates this will continue in the same fashion at least up to 700ppm.
2. As a soil scientist/plant physiologist, I can’t address ocean sequestration of CO2. But I hypothesize that the general concept of increasing growth in response to increasing CO2, die-off and sequestration of CO2 in oceanic sedimentation would be similar to terrestrial cycles.
3. Under controlled growth chamber experiments and ideal conditions, plant response to increasing [pCO2] is exponential not linear. Increased growth leads to increased sink (larger plants), leading to further increased growth. Sometimes that increases economic yield, sometimes it just increases biomass. So the issue hinges on the afore-mentioned liebig most limiting factor(s) or mitscherlitz response curves to deficient supplied growth factors. Available light never limits growth response in ambient environmental conditions, it only occurs in light impeded greenhouses (or in cloudy environments). In efficient plant species growing in ambient temperatures that do not cause reduced enzymatic efficiency ( 92 F – 98 F roughly for most C3 and C4 plants , respectively) growth is most limited by the genetic ability to translocate photoassimilate to developing sinks. During daylight hours chloroplasts become feedback impaired by the accumulation of photoassimilate both within the chloroplast itself and in cellular starch granules. Under the process known as dark respiration, these metabolites are transported to the sinks. Deprivation of the dark cycle results in a reduction of genetically acheivable growth to plants in ambient conditions. The necessity for supplemental lighting is a result of greenhouse enclosure reflection of total radiation or specific wavelengths. The majority of increased yields historically acheived have been determined to be increased harvest index, translocation efficiency and other genetic improvements. Outside of these, the main constraints to estimations of increased global biomass are water, both absolute and seasonal timeliness, and nitrogen, then phosphorus, etc. Since the improvement in availability of all growth limiting requirements, and therefore in sequestration of increasing amounts of Anthro… supplied CO2 fertilizer is directly proportional to the cost and availability of energy (to mine, to build water storage structures and canals, to transport, etc.), it behooves mankind to continue to develop energy resources, most notably nuclear. And to continue advances in plant genetics and response to environment, so pony up some money for some real research. ;~D
Jeff Id: “What it says is, yes there is statistically more CO2 but that CO2 isn’t building up. It’s being absorbed as fast as we emit it.”
I hope I misunderstand you, because this seems like an odd statement. CO2 most definitely is building up in the atmosphere; that’s the thin black line in Figure 1. That line is increasing, meaning CO2 is not being absorbed by the oceans/soil/biosphere as quickly as we emit it.
The paper is simply saying the fraction going into the atmosphere (vs elsewhere) has not changed.
Sophistry in politics (10:32:07) :
Then if you consider that these natural sources can vary up or down in one day by more than ten times what we are able to produce in a whole year you get even more perspective.
Be careful, the figures you use from Vienna are local CO2 levels in a town, nothing to do with global levels which don’t change with more than a fraction of a ppmv per day (global average 5 ppmv over the seasons for 1 degr.C change).
And the micro-Schollander method used in Barrow had an accuracy of +/- 150 ppmv (!). It was intended for measuring CO2 levels in exhaled air (at 20,000 ppmv), not for 300 ppmv in ambient air.
It seems that you rely on the work of Ernst Beck (on historical CO2 measurements) and Jaworowski (on ice cores), but both have their problems… See:
http://www.ferdinand-engelbeen.be/klimaat/beck_data.html and
http://www.ferdinand-engelbeen.be/klimaat/jaworowski.html
Lucy Skywalker: “In the oceans overall, there is always a surplus of calcium ions (Ca++) ready to absorb extra CO2. The little molluscs are everywhere, wrapping up any hint of excess in their shells. Moreover, all the animal and plant life in the oceans need CO2 – again, it is the most fundamental, basic, vital food. Anyone suggesting anything else is a bad scientist. Every bit of CO2 we can get is precious to the biosphere and I hate Al Gore for forcing on people the lie that it is a pollutant.”
The above was worth repeating.
Irrefutable.
Chris
Norfolk, VA, USA
@carrot eater
But as the measured increase (in the atmosphere) is close to linear, and the anthropogenic output (allegedly) is close to exponential, either the natural carbon sinks must increase or the natural output must diminish (or a combination), yes?
Cassanders
In Cod we trust
Tim Clark:
“Someone stated that 45% of anthropogenic CO2 releases remain in the atsmosphere. I believe the poster confused”
That somebody was not a poster, it was the author of the paper being discussed here: Knorr. I think you are confusing the airborne lifetime of an individual CO2 molecule with the overall net accumulations of CO2 in the different sinks (air, ocean, bio).
maksimovich: I don’t see how Marinov’s modeling results (2006) show that that Le Quéré’s (2007) work is incorrect, but in any case, I’ve been using very weak language with Le Quéré’s results for a reason. They’re very preliminary results, and have drawn critical responses. Also, my apologies: I see I described Le Quéré’s work as empirical, but it uses models heavily as well.
But in any case, the point is that any evidence for an already weakening ocean sink is weak and preliminary, to the extent that there is any such evidence. So Knorr’s results aren’t all that surprising or earthshaking. There’s no big trend yet; the question is, will there be one in 50 years?
carrot eater (11:13:24) :
I was wrong above. Timetochooseagain pointed out that the lower part of the graph is ‘change in co2’ rather than co2 level. My bad.
The paper means the sinks are working harder not that they’re keeping up.
I find this paper curious in the context that the oceans release and absorb 20 times as much CO2 as man (IPCC quote). The areas of absorption and degassing vary at different times of the year. The result is that the there is about 2% of the CO2 in the atmosphere being derived from fossil fuels. (I do have links somewhere). I have assumed that the recent increasing CO2 concentrations may have been caused by increasing ocean temperatures, producing a net outgassing, rather than by man. Does this paper imply that the increasing CO2 concentrations are definitely a result of man’s activity ?
What interests me most is two little blips in the manmade CO2 emissions record. If (as Ferdinand suggests) the CO2 increase really reflects the manmade increase, then it seems to me there should be CO2 decrease blips to match the manmade blips. But they are not there. I have to thank Derek Alker who pointed this out. And this supports my belief that the apparently constant proportion between our emissions and CO2 increase is largely sheer coincidence – that the CO2 increase is due to oceans warming and outgassing – and that the total CO2 turnover is so large that (with the biosphere) small changes can easily be absorbed in the longer term by the biosphere itself expanding or shrinking. Past CO2 levels have only dropped after the temperature had dropped substantially (ice core records). Perhaps dissolving in the oceans is a slower process than outgassing. Perhaps the plant kingdom has evolved to not use more than 50% of any year’s increase, on the grounds that boom-and-bust is not a good longterm overall strategy for the top species.
carrot eater (07:32:17) :
Ferdinand Engelbeen: You’ve done a nice job trying to explain, but I must take issue with you on comments like this:
“The models on the other hand are programmed to show a saturation of the oceans and vegetation. In that case, the airborne fraction would increase.”
I realize that my take on models were influencing my thoughts… In my former working life, I had some experience with models, be it for physical/chemical processes, not for climate. If you don’t know all important ingredients and (inter)actions, then your model goes anywhere except giving the right answer if something happens with which was not incorporated in the model…
But let’s have a thought about the (possible) future: the upper ocean level is in direct contact with the atmosphere and simply follows the CO2 levels of the atmosphere with some delay. Of more importance is the CO2 flow into the deep oceans. The partial pressure difference for the coldest parts of the oceans, where e.g. the deep ocean conveyer belt is sinking (NE Atlantic) is about 220 microatm air-sea surface. This will increase over time, together with the emissions, while the sea surface doesn’t change much in chemical composition, except for absorbing more CO2 under this higher pressure difference. I don’t see any reason why this should reduce in rate.
At the other side of the oceans, mainly in the tropical Pacific, deep ocean water is upwelling after a lot of time (800-1600 years), but during many centuries not different from the current composition. Thus the main source of natural CO2 is relative constant (besides an ocean temperature component), while the sink is increasing in ratio with increasing CO2 emissions.
When does the ratio go down? Normally when higher CO2 levels in the deep ocean return to the surface. Until now, humans have emitted about 350 GtC as CO2. The deep oceans contain some 38,000 GtC as (bi)carbonate. Or the total emissions over the past centuries increased the deep ocean carbon content with less than 0.1%, which may influence CO2 levels in the atmosphere 800 years from now… Thus even if we assume that we will emit ten times more in total quantity this century, that will influence the CO2 levels in the far future with about 3 ppmv over the pre-industrial level…
“little blips” in the manmade co2 record aren’t enough to show up in the mauna loa co2 record. The little blips are slight downturns in emissions, which only slightly slow down co2 rise, not enough I believe to show up.
Jeff Id (10:19:35) :
There are a lot of people missing the point of this paper. What it says is, yes there is statistically more CO2 but that CO2 isn’t building up. It’s being absorbed as fast as we emit it.
No the paper doesn’t say that. It says that CO2 is “building up” at a slower rate than expected.
According to the paper, humans emitted 2 Gt of CO2 in 1850 of which ~1Gt was absorbed and ~1Gt remained in the atmosphere. In recent years, human CO2 emissions have risen to ~35 Gt. Intuitively we might expect that the earth would continue to absorb ~1Gt and leave ~34 Gt in the atmosphere. This is not what is happening. Apparently the same proportion (roughly half) is still being absorbed while the other half accumulates in the atmosphere (the actual values are 55% and 45% respectively) . CO2 is still accumulating in the atmosphere – just not as quickly as thought likely.
A quick back of the envelope calculation shows that atmospheric CO2 has been increasing at the rate of ~0.43% per year. If this rate continues indefinitely then the pre-industrial level of 285 ppm will be doubled in another ~89 years.
Ferdinand Engelbeen (06:11:35) :
Greenhouse growers in The Netherlands and other countries use 1,000 ppmv as guideline (more doesn’t add much growth), or about 2.5xCO2.
Thus indeed in general there is more growth, but not 100% more growth for a 100% higher CO2 concentration. Lack of light, low temperatures, lack of sufficient amounts of minerals/fertiliser or water may be limiting growth despite increased CO2 levels…
I suggest you watch a video titled (Global Warming or Global Governance), start about half way through, This section shows plant growth in higher levels of CO2.
Anne van der Bom (04:16:49)
Thermometers only measure the micro system surrounding the thermometer, urban heat island = rise in temperature, check the rural sites, not much of a sudden increase there.
http://i446.photobucket.com/albums/qq187/bobclive/armagh_air_temp2.jpg
Re: Smokey,
My analysis of CO2 isotope data shows that about two thirds of atmospheric CO2 is going through an inorganic cycle and about one third through the biosphere(which includes fossil fuels). http://www.kidswincom.net/climate.pdf
Cassanders: I’m not sure your eyeballing of curves as linear or exponential is a good way to advance. On a short scale, anything can look linear. One should actually do the math. Knorr did so here, and found that the fraction accumulating in the air has been constant over time. I do have some reservations about Knorr’s methods, though.
There is apparently a sharp difference of opinion among the commenters here: some are happy to see that the oceans are continuing to be efficient carbon sinks; others think the oceans are net outgassing, and are thus sources of CO2, not sinks at all. That’s quite the contradiction. I don’t understand why anybody thinks the oceans are net sources.
Ferdinand Engelbeen: My point was that you shouldn’t say the models say x, when they don’t actually say x. Whatever issues models have, let’s not misreport their results. The details of how temperature, atmospheric CO2, the solubility pump, biological pump, air and ocean circulation patterns will combine to determine the effectiveness of the ocean sink is beyond my competence on the matter, so I’ll not get into that.
Why are these scientists taking real measurements & collecting empirical data like this??…..they forgot that the ‘science’ was ‘settled’ apparently?…i mean come on what are they trying to pull?
Anne van der Bom (06:07:49)
In a greenhouse the other factors that determine plant growth are carefully adjusted to match the higher CO2 level. Temperature is one, light is another. Those greenhouses you speak of mostly have nighttime assimilation lighting and increased temperatures and generous amounts of fertilizer are being applied. ;-
People should come to “Westland”, its a part South-Holland in the Netherlands, and it is where i live, assimilation lighting requires screens these days to prevent light flooding/leaking out of the greenhouses, yet still a [snip] load of light comes from these greenhouses.
If the circumstances are right (snowdeck and low cloudcover) at night than it is still quite able to screw-up your day and night rythem if you don’t use heavy curtains to keep out the lights.
But then, this tiny overcrowded country is still a large exporter of flowers and the greenstuff(1) we call food.
(1) the other greenstuff grows also very well in these circumstances, i like to quote the former head of the Dutch Secret service on this: “Its still Dutch agriculture at its very best”.
It is Dr. Romm, Chip
I believe the technical term for ‘doctors’ who claim to know more than they do is ‘quack’.