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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P Wilson (20:41:06) :
sorry I wasn’t so clear. 45% AC02 (the other 55% absorbed) represents 2% of all aerial c02
Looking at that in another way: the 2% you are looking at here is only from one year. If there wasn’t a seasonal exchange with the oceans and vegetation at all, you need to add the 45% of last year, 45% of the year before that, back to the first additions in 1750…
The total human emissions since 1750 were 335 GtC from fossil fuel burning (up to 2006), some 110 GtC from land use change. Of these additions, some 45% or about 200 GtC or 100 ppmv remained in the atmosphere, which is wat is measured.
Thus the fraction of human induced CO2 would be over 30%, if there was no exchange of CO2 molecules (not influencing the total mass) over the seasons. But as there is a huge exchange of about 20% per year, most human CO2 is replaced by natural CO2 over time. Again that doesn’t change the total mass of CO2 in the atmosphere, only changes the “type” of CO2.
carrot eater (14:31:09) :
I haven’t looked back at this until now. On the off chance that you will ever read this, you continued simply to show that you are confused by the concept of bounding. If I have an integral where the integrand is positive, I can easily prove that the integral is bounded by the maximum value of the integrand within the interval of integration times the size of that interval. This is really basic.
And, I was not projecting anything beyond the integration interval. I was questioning whether the behavior to date was consistent.
In 1960 the CO2 level was 316ppm. Today it is 387ppm. Source:
http://www.esrl.noaa.gov/gmd/ccgg/trends/co2_data_mlo.html
That’s an increase of 22% since 1960. I’m sure we have increased our CO2 output more than that in the past 50 years. Given that higher temps have warmed the seas and melted ice, thus adding even more CO2 to the atmosphere, you would expect it to be higher.
These reports are good news. It seems that natural systems have increased their absorption of CO2. Plants, oceans and so forth don’t know how much CO2 we are emitting right now — just that the CO2 in the atmosphere is greater now. That means that sinks should keep on absorbing CO2 at a higher rate even if we dramatically reduce our levels of emissions. That means that reducing our CO2 emissions might actually work. The absorption rate in 2000 (about 3-4 on the figure equals our emission rate in 1960 or so. That implies that if were somehow able to emit at 1960 levels the total CO2 might even stop going up!
Unfortunately, the temperatures will still keep rising even if were able to halt at the current CO2 level. I don’t think anyone really knows what the new global averages will be or how long it will take to get there. However, an interesting study
(see the original Press Release http://www.universityofcalifornia.edu/news/article/22071 )
found the last time we had this much CO2 was 15 million years ago. At that time temperatures were 5-10F higher, the equator was arid and there were no ice caps. Sea levels were 75-120 feet higher — which wipes out Bangladesh, the Mississippi basin, Polynesia and many other places besides. 15 million years is a pretty long baseline — enough to smooth over even ice age cycles and any expected climate variance.
I think its a bit selfish to just assume that this is a problem for future generations and ignore it. Unfortunately there is a lot of noise in both the data and models — and the uncertainty could go either way. We don’t know how long we have to fix things.
James,
You surely know that rises in CO2 follow rises in temperature: click
Which makes all the emotional arm-waving in your linked article irrelevant.
CO2 is a function of temperature, not vice versa. So relax. That very minor trace gas isn’t gonna getcha. The taxman might, though, if you buy into the CO2 globaloney.
Bart, if you’re only looking for a snapshot in time, then don’t write a differential equation like dC/dt = whatever. Just look at Figure
But your bigger problem remains: If you write a model as a differential equation, and upon solving it it wanders off from the initial condition for no reason whatsoever, then your model isn’t usable. As simple as that.
Bart, I perfectly understand what you’re trying to do by using an apparently limiting upper value for some variable; it just isn’t a good method for the way you were proceeding.
If you’re only looking for a snapshot at the current time, then don’t even bother writing a differential equation like dC/dt = whatever. Just look at Figure 1 in the paper above, and a chart showing the carbon cycle. Humans emit x; y of it accumulates here, z of it accumulates there. End of story. If that’s all you want to check, then no need for a model.
If you’re interested in how all those quantities change over the years, including the amount of carbon in the atmosphere, ocean and biosphere, as well as the flows in between them, then you need to write the differential equations, and every single term in those equations needs to change with time in a realistic way. If a term actually is relatively constant, then you can be lazy and treat it as a constant. But an important part of the dynamics here is that the human emissions are NOT constant (as seen in Fig 1). So if your model is going tell you anything useful, it better not treat it as such.
And finally, and this is a general statement: if you write a differential equation, and when you solve it you find it wanders off from the initial conditions for no good reason, then there’s something wrong with your differential equation. You aren’t going to learn anything useful from it.
“If you write a model as a differential equation, and upon solving it it wanders off from the initial condition for no reason whatsoever…”
It doesn’t.
“I perfectly understand what you’re trying to do by using an apparently limiting upper value for some variable; it just isn’t a good method for the way you were proceeding.”
Then, you do not understand it.
Michael Hulme’s book “Why we disagree about Climate Change”;
“…Because the idea of climate change is so plastic, it can be deployed across many of our human projects and can serve many of our phsycological, ethical, and spiritual needs. …..
We will continue to tell new stories about climate change and mobilize them in support of our projects…
These myths transcend the scientific categories of true and false….”
There you have it in a nutshell. Methane is next.
Dont vote for people who believe in this junk-science.
For those interested in whether the osceans will be saturated by CO2, you may read what the experts say;
http://folk.uio.no/tomvs/esef/esef0.htm
and click on entry
4. Chemical Laws for Distribution of CO2 in Nature;
http://folk.uio.no/tomvs/esef/esef4.htm
It wont be saturated.
And while I am at it; Entry 5;
http://folk.uio.no/tomvs/esef/esef5.htm
Segalstad says CO2 turnaround time is approx. 5.4 years.
Another nail in the AGW coffin.
I am very grateful for those contributors to WUWT who understand science and math far better than I, who post such clear expositions as kwik and others do. Far better to struggle a little with coming to an understanding than to accept nonsense as some kind of holy writ. An education and professional life in Fine Arts doesn’t mean science and math were too difficult for me when I trained, I simply had no passion for them then; finding counter-arguments based on actual evidence to show up the obvious crap spouted by the AGW alarmists for what it is has required me to take a real interest in science and math and re-educate myself so I can at least understand the debate.
Thanks again!
Sorry – was interrupted.
I have learnt so much since being directed to WUWT during the Copenhagen conference, I find I now can’t be bothered reading the specious rubbish that MSM organs such as London’s Guardian newspaper publish on the topic. My disillusion with MSM is quite profound, even though I’m old enough to be cynical about the Meeja, I tended to read in hope of honest reporting!
I think the Knorr report is a “bombshell”.
AGW is based on the recent increases in CO2 are solely due to mankind and not natural increases.
“Carbon dioxide is released to the atmosphere by a variety of sources, and over 95% percent of these emissions would occur even if human beings were not present on Earth”
http://www.gcrio.org/ipcc/qa/05.htm
Currently anthropogenic activities only accounts for about 5% of the total annual Carbon (CO2) emissions into the atmosphere. If the ratio of man caused CO2 and natural CO2 present in the atmosphere hasn’t changed in 160 years, then 95% of the increase should be caused by natural releases.
And note, the sequestering of CO2 from the atmosphere is independent of the source of the CO2. Nature doesn’t treat a “naturally” emitted molecule any different than one from a jet afterburner. If 55% of 5% is being removed, than 55% of 95% is also.
I don’t see how recent increase in CO2 levels can be solely driven by man unless its ratio increases.
We live in interesting times.
Great article!
I just stumbled upon http://www.skepticalscience.com/Is-the-airborne-fraction-of-anthropogenic-CO2-emissions-increasing.html
They say that Anthony misunderstood the science. What is our position on this? How do we debunk the http://www.skepticalscience.com/Is-the-airborne-fraction-of-anthropogenic-CO2-emissions-increasing.html article?
Also, how do we debunk the post by real climate?
http://www.realclimate.org/index.php/archives/2010/01/unforced-variations-2/
The alarmists claim that “The confusion in the denialosphere is based on a misunderstanding between ‘airborne fraction of CO2 emissions’ (not changing very much) and ‘CO2 fraction in the air’ (changing very rapidly)”
Bigbo, I havn’t read these Skeptical Science and RC posts yet, but I guess they discuss with some ad hom and demand that averyone should stick to IPCC dogma. But this study and facts in general suggest problems with that.
I’m no pro, but decreased airborne fraction should be logical since emission increase is larger than CO2 increase rate in the atmosphere. By google I (first hit…) find Dr. Jarl Ahlbeck, who mention: “In reality, the increase rate of atmospheric carbon dioxide has, despite the substantial increase of carbon dioxide emissions, remained on a very stable level during the recent 30 years. In fact, the airborne fraction, or the portion of the yearly emissions that stays in the atmosphere, has decreased from 52% in the year 1970 to 39% today. The IPCC model using IS92a implies however a nearly constant future airborne fraction”.
IPCC’s view is that the increase so far is only because of human emissions, but in that case a 0.3 correlation between temperature anomaly and increase in CO2 rate is hard to explain; Dr. Roy Spencer:
http://wattsupwiththat.wordpress.com/2008/01/25/double-whammy-friday-roy-spencer-on-how-oceans-are-driving-co2
IPCC also believed that the increase rate of methane would soar, but it stopped to increase. Recently MIT showed that humans are not causing current changes in methane concentration:
http://tgdaily.com/html_tmp/content-view-39973-113.html
Watts, and others, are right when they say that our understanding of this isn’t so sure as IPCC suggests.
My tgdaily link didn’t work, but I found a cashe file:
The October 30 2008 article’s introduction:
Boston (MA) – Scientists at MIT have recorded a nearly simultaneous world-wide increase in methane levels. This is the first increase in ten years, and what baffles science is that this data contradicts theories stating man is the primary source of increase for this greenhouse gas. It takes about one full year for gases generated in the highly industrial northern hemisphere to cycle through and reach the southern hemisphere. However, since all worldwide levels rose simultaneously throughout the same year, it is now believed this may be part of a natural cycle in mother nature – and not the direct result of man’s contributions.
Matthew Rigby and Ronald Prinn lead authors in the paper published in Geophysical Review Letters.
Bigbo. My guess that Skeptical Science and RC used ad hominen wrong! Mea culpa. I just watched their posts, and Skeptical Science seems to say that this isn’t a bombshell. They may be right, but this should be annoying data which not supports IPCC’s carbon cycle. Skeptical Science says that if one change the raw data with a filter one get statistically significant increase, but that would be unscientific method (more like fraud…). (The report mention it; I don’t know why.)
RC seems to be annoyed… (sorry if this is ad hom from me, but RC write “sigh” after they find that their accusation against Sciency Daily’s headline was answered with that Science Daily just used AGU’s conclusion).
I’m not sure how this article makes a difference. Here is the source of my confusion:
It is my understanding that the oceans both absorb and give off CO2, so there is a constant exchange of CO2 between the oceans and the atmosphere. Even if the oceans were completely saturated with CO2, they would still exchange CO2 with the atmosphere.
If the oceans are a sink, they are absorbing more than they release. If the oceans are saturated, they absorb the same amount that they release. This means saturated oceans would either absorb less CO2, or release more CO2, or both (as compared with sink oceans).
It appears in this post there is an assumption that saturated oceans would absorb less CO2 than sink oceans. However, do we know this assumption is correct? Why wouldn’t saturated oceans absorb the same amount as sink oceans, while releasing more CO2 than sink oceans?
This paper assumes that the ice core proxy data for CO2 is correct. Having made many CO2 measurements with chemical equipment (which is as accurate as present instrumental measurements if not better) I favour the data presented in a peer review article by Ernst-Georg Beck 2009 see http://www.biomind.de/realCO2/realCO2-1.htm
This shows that in 1939-1942 that the CO2 background concentration in the atmosphere was about the same as at present. Beck has shown that there is a lag of around 5 yrs of peak CO2 from peak the mid 1930’s temperatures recorded in USA.
This shows conclusively that heat absorption by man emitted CO2 can not be the driver of atmospheric temperature.
Another point, all the text books on heat transfer state clearly that the driver of heat transfer is temperature difference. The concept of forcing by CO2 is nonsense. Gases in the atmosphere will only transfer heat to and from by convection or radiation if there is a temperature difference.
Read the article and the posting, “anthropogenic CO2 emissions. This is an important claim, because so far only about 40% of those emissions have stayed in the atmosphere.”
If this is true then the science is based on BS ( bad science ) the methoid used to determine “anthropogenic” carbon from “natural” carbon is flawed. An unchanged ratio over extended period is not logical. Would not be the first time the wrong conclusive result was caused by a mistake in the original input premise.
Done it myself a few times 🙁
Ferdinand Engelbeen (14:23:40)
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).
_____________
Thank you for the citation Ferdinand, and Happy New Year to you and your family.
I personally enjoyed your comments here, and found your explanations to be very well-stated. I further enjoyed the earlier exchanges between you and Richard Courtney on this subject. Richard spoke against your “mass balance argument” far better than I did. You both did such a good job that I’m not sure who I agreed with from day to day, so I’ll just hold to my original conclusions for now…
The fact remains that the only signal I’ve been able to detect in the data is that CO2 lags temperature by ~9 months in the short-term ~ENSO cycle. CO2 also lags temperature by ~800 years in the much longer cycle(s) measured in ice cores.
We also know that 12-month dCO2/dt at Mauna Loa has “gone negative” several times since CO2 measurements began there in 1958: one month of 12 in each of 1959, 1963, 1964 and 1971, and three months in 1965 and 1974.
Still, there is that nagging upward overall trend, which could reflect the manmade component – or not.
I am not as willing as some others to dismiss Ernst Beck’s data and thoughts. Time will tell…
In any case, this dCO2/dt argument, while scientifically interesting, is not that critical to the big question of alleged catastrophic manmade global warming. There is increasing evidence that the sensitivity of climate to increased atmospheric CO2 is so low as to be practically inconsequential. The IPCC model numbers are about an order of magnitude too high, and there is no evidence of any “climate tipping point”.
The ClimateGate emails have certainly put a different spin on this core science argument – everything we have written on these core issues has been technically vindicated – we just thought the other side of the argument was wrong – we were reluctant to suggest that they were utterly dishonest, a reluctance they did not share in their discussion of our motives.
I understand we are in for some serious cold temperatures in the Northern Hemisphere in the next few weeks. Bundle up and stay warm.
Best regards, Allan
FORECAST CO2 SEE:
http://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxlYXJ0aHF1YWtlcHJlZGljdGlvbmJ5amFjfGd4OjJjMWIxODBiMmRmMjFiZTk
and
http://sites.google.com/site/earthquakepredictionbyjac/Home/greenhouse-effect
Best regards, Jacek