I’ve been getting a lot of requests to cover this story, probably 20 or so now with wonderings about “why haven’t you covered this yet?”
How quickly you all forget. WUWT was the very first to cover this story back on November 10th, 2009.
Everybody else in the media today is playing catch-up. So if you’d like to read the original press release and participate in the already ripe comments left then, see this WUWT story:
Scott (08:46:03) :
“…to change the carbonate concentration of the ocean by 1% would still require a full 175 years assuming no biological or chemical compensation/buffering/dampening. Consequently, these basic calculations still support the article–nature’s natural uptake of CO2 is nowhere near its capacity.”
This is the key point. In this case it is reasonable to suppose that the rate of sequestration is roughly proportional to the amount of CO2 in the atmosphere, A; that is, equal to kA where k is roughly constant. A simple mass balance of the atmosphere is then
dA/dt = R – kA
where R is the rate of production of CO2 from all sources (incl human). This indicates that A approaches a steady-state value Ass (but depending on the magnitude of k, and whether R is changing rapidly, might not be observed to actually reach Ass) given by
Ass = R/k
If k is roughly constant this shows that separate contributions to R directly translate into a contribution to Ass. So if human activity contributes a ~%5 addition to R it contributes a ~5% contribution to Ass (ie to atmospheric CO2).
Note that this conclusion doesn’t require us to have highly accurate measures of the components of R. If we are confident to say “humans make a small contribution to the overall rate of CO2 production” then we should be confident to say “humans make a small contribution to atmospheric CO2”.
The key lines were contained in parenthesis just before the line graph (which substantiated them). This does NOT mean that atmospheric CO2 from human generated sources have not increased. They clearly have and exponentially so. It means only that the proportion of such gases retained in the atmosphere has remained constant, a fact the IPCC and Hanson and many others have long recognized.
So where do you get off concluding that taking drastic steps is somehow out of line with the science?
Lucy Skywalker (06:39:53) :
Ferdinand Engelbeen (07:34:39) :
“5.1 This is the heart of the matter: as long as the natural sinks are larger than the natural sources, nature adds nothing, nada, zero, to the total mass of CO2 in the atmosphere.”
Incorrect. This is very subtle, but try to see it through.
In a feedback system, the mechanism taking out will always expand in reaction to an increase in the disturbing signal. If the natural sources expand, so will the sinks. If the artificial sources expand, so will the sinks. The sinks will therefore always be greater than the natural sources alone. What you are stating here is not a profound insight – it is a tautology.
5.2 About ice cores:
“I haven’t plotted the data before 1900, as there were far less emissions and the signal/noise ratio may be problematic.”
Then, you must proffer justification for the S/N being un-problematic after 1900. The fact is, the curve is very smooth. I see no justification for eliminating the pre-1900 record on that basis. And, what it shows is that CO2 was already rising before the age of industrialization. There is no conclusive evidence, therefore, that the rise, although bearing superficial resemblance to the temperature record (see Lucy Skywalker (06:39:53) above for refutation of this) is driving the temperature record. Indeed, I see evidence in your own data that the inflection of the atmospheric CO2 concentration rise preceeds that of the accumulated emissions. You could argue that the time of precedence is arbitrary, since the ice core data was phase advanced to match the instrument record, and this advance is itself a statistical parameter with some variation, but in arguing that it could be so variable, you will undercut other AGW arguments which rely on the necessary phase advance being well known.
Is it really credible that the inflections could have occurred at roughly the same time and not be related? Let me suspend my suspicions, for a moment, that the data have been “adjusted”, and the unadjusted data might not show such an approximate happenstance – I will just ignore for the moment the fact that the ice core data are phase advanced to match up with the instrument record, and that the idea that we could calculate historical anthorpogenic emissions to such a smooth curve with zero error bars is fantastic. Now, taking the data at face value, is it really credible that the inflections could have occurred at roughly the same time and not be related?
I believe, based on my experiences in the wild world of statistics, that it is. The simplest example of the anti-intuitive properties of statistics is probably one most technical types have encountered in their first probability class. The professor comes in and asks everyone their birthday. In a class of 30 students, the odds are better than 2 in 3 that at least two people will have the same birthday. When it happens, all the neophytes are amazed, because it just doesn’t seem likely, given the way our brains have been programmed before we encounter such mathematics.
To calculate the probability, we would need to know how frequent such upsurges are. Then, we could have an idea of how often such an event would coincide, within a space of some interval of years, with a randomly selected instant in time, such as the time at which the human race moved into massive industrialization. The regnant orthodoxy argues that such events are rare, but then, it argues there was no MWP as well, and we all know that is false.
“The (Law Dome) ice core CO2 levels and the CO2 emissions for the period 1900-1959 have about the same ratio as for the period after 1960 with more accurate measurements:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_1959.jpg“
Any two trends will have the same ratio for all periods in which they exist. Again, this is tautology.
“What do you think that caused the exact parallel change of d13C and CO2 in ice cores (and atmosphere)?”
There is no doubt that CO2 has been rising, from whatever source.It is not d13C which gives an indication of change, it is d(13C/12C). The hypothesis that the ratio has decreased because of increasing 12C is only one possibility.In this link, Dr. Spencer argued convincingly that the ratio naturally rises and falls with absorption and release of CO2 from the ocean due to SST. (I really hope you will not argue that Dr. Spencer’s analysis is flawed along the imbecilic lines of some of our trolls – I will be most disappointed).
“5.4 Is meant for the period before the atomic bomb testing: carbon dating had to be adjusted for the dilution of 14C in the atmosphere by the burning of essentially 14C free carbon from fossil fuels.”
The period of massive industrialization and accelerated anthropogenic CO2 release came after the bomb testing. The fact that 14C has decreased since then is in no way conclusively attributable to the accelerated anthropogenic production – there is no way you could convince me you could pick such a small signal out of such enormous hash. Indeed, you are the only researcher I have seen to claim such. Most analyses I have seen explicitly state that 14C is not useful for this purpose, and they focus on the d(13C/12C) ratio.
5.5 There are only two relative fast sources of CO2 in the atmosphere: the oceans and vegetation decay [as far as I (you) know] (volcanic being a minor source and in the recent decade rather quiet). Oceans as main source are impossible: d13C level is too high [as far as I (you) know] .
High 13C is indicative of non-fossil fuel source, according to the hypothesis. Plants marginally prefer 12C, so fossil fuel burning is supposed to raise 12C, resulting in a lower 13C/12C ratio. I think you rushed in writing this and meant to say this, so I am going to assume you are arguing the opposite of what you say. However, this link I sent earlier argues that the picture is much more muddled than this simple set of assumptions would suggest. So I think, again, there is too much of a signal to noise problem here to draw conclusive, er, conclusions.
5.6 … the average flow is from the atmosphere to the oceans, not the other way out.
We don’t know that. You are basing the hypothesis on the 13C/12C ratio. As I have stated previously, I reject that line of argument.
Oops, forgot to cut out the Lucy Skywalker (06:39:53) : at the top. I was saving that link because I wanted to look into it in more detail. Thanks, Lucy.
Incidentally, on this:
“Then, we could have an idea of how often such an event would coincide, within a space of some interval of years, with a randomly selected instant in time, such as the time at which the human race moved into massive industrialization.”
In actuality, the inflection in the atmospheric CO2 curve appears to be due to some random event, such as occurs earlier in the record, but larger, at or around the year 1943. I was curious if that might coincide with some volcanic event. There is this.
anna v (04:44:41)
anna v, a good question. CO2 is what is called a “well mixed” greenhouse gas. Per the map at the head of this thread, it varies less than ± 1% around the globe. If temperature varied this little around the planet, it would certainly be reasonable to measure the temperature in the same way.
The CO2 level measured in Mauna Loa is mainly used to measure the trend in CO2. For detailed purposes, it is not generally claimed to be the exact average CO2 around the globe, as there are other CO2 measuring stations. These vary slightly from the Mauna Loa measurements, and show a general trend of more CO2 in the Northern Hemisphere and less in the Southern Hemisphere.
It is close enough to the global average for general purposes, however, because for most of the things that we are discussing a value within ±1% is more than adequate, and much more accurate than most other things we can measure about the climate.
There are plenty of bad or inaccurate measurements in climate science, and enough incorrect claims, to keep us busy for a long time. Attacking the few good measurements merely hurts our credibility.
Scott says:
Glad you found your error in the atmospheric concentration calculations. I was going to tell you that your result seemed to be off by about 6 orders of magnitude, which indeed turned out to be the case. As for your ocean calculation, I can’t tell you exactly what is wrong with it at the moment but I would suggest that you read a textbook or article that goes through such calculations. (One example is “Global Warming: The Hard Science” by L.D. Danny Harvey.) A lot of people have already thought hard about these chemical reactions and mixing in the ocean and you will likely benefit from their insights.
Steve Keohane says:
I believe that most of the annual cycle in CO2 levels is actually driven by the biosphere. So, CO2 concentration peaks in the late winter / early spring because this is just before plants start taking up a lot of CO2.
JamesG (09:22:09) :
Ferdinand
“It is good to be sceptical, but there is a difference between being sceptical and simply rejecting data, only because you don’t like them.”
Let’s be clear that’s exactly what Callendar and Keeling did. And that’s what you do too when you discuss Beck’s work or the stomata data. It’s very easy to reject a paper as “not reliable” when you don’t trust the accuracy of the measurement methods and you know that lot’s of people know the conclusion they want and get there by assumptions. But that’s a sword that cuts both ways. As you know, there are very few climate papers that stand up to close scrutiny – an awful lot is grounded on handwaved assumptions and finished by poor stats. And the number of arbitrary fiddle factors used in this game is astounding.
It near impossible for me to react on all reactions…
At the moment that Callendar collected his graph, he had several a priory criteria (not after-the-fact criteria as many climate science articles of today) which he did use to include or exclude CO2 measurements. One of the criteria was that the measurements might not be used for agricultural purposes. Why? Because it was known, even in that time, that such measurements showed a huge positive bias. Not because that would disprove AGW, as that wasn’t even thought to be a problem, even beneficial. That criterium excludes the measurements of Giessen (Germany) and Poona (India). Without these two series, no 1942 peak in Beck’s historical data graph.
That is the main problem with Beck’s data: many of the series are taken over land within forests, fields, gardens,… CO2 levels taken over the oceans or coastal with wind from the oceans show much lower values and are around the ice core values (which were sampled decades later), so Callendar was right to use these criteria.
I still wonder why some skeptics use different criteria for temperature readings and CO2 measurements: temperature readings are (rightfully) discarded if taken on parking lots, asphalt roofs, near AC exhausts, etc. But for CO2 measurements, one accepts without hesitation any (even impossible) value, as long as it is high enough to counter the “man-made” increase…
What Ernst Beck has done is the equivalent of taking a temperature series from Helsinki mid-winter add the temperature (even from one day) in Rome on a hot summer roof as representive for the next year, add the temperature of a few months in Antarctica for the following year,… without any selection criteria, just averaging everything, reliable or not, representive or not, and then conclude that the middle year was much warmer than the previous and following year…
The 1942 80 ppmv CO2 peak in Beck’s graph is physically near impossible: that would include a release of 160 GtC as CO2 within a few years, and completely impossible: the disappearing of the same amount of CO2 within a few years. There is not the slightest sign of such a huge change in CO2 around 1942 in any other proxy (temperature, ice cores, SI index, d13C levels in ice, trees, coralline sponges),… Thus there is no supporting evidence for a 1942 peak in CO2.
I would love to believe Beck’s graph, as that would kill one of the cornerstones of AGW, but I can’t, because it isn’t true, as all other indications don’t show such a change, even not in high resolution (coralline sponges 2-4 year).
Your own arguments rest on two main bits of evidence; the C12/C13 fractioning and the ice core data. As Spencer showed you, the first argument fails quite easily when you do a simple control test. The second rests on a few cores from the Antarctic. AFAIK the Arctic data doesn’t support the hypothesis and the stomata work contradicts it. We also know – because they tell us – that the different CO2 station data are all calibrated against each other. And we know too that researchers in this field are prone to cherry-pick data that fits the paradigm and thusly find signals in the noise. As for the CO2 being well-mixed, well I always suspected that was overly simplistic and it hasn’t yet been proven – the AIRS people saying it isn’t true but remaining cagey.
It is false that the CO2 data are intercalibrated, the calibration gases are intercalibrated, not the data! That is normal practice for any quality laboratory, without that, one can indeed fabricate any trend one wishes…
My own arguments rest on more than the ice core or d13C data, the basic point is the mass balance. The 13C/12C ratio was extensively discussed on this blog with Dr. Spencer, see my comments in that discussion. It is some time ago, but the basic point was that Dr. Spencer underestimated the strength of the d13C signal caused by fossil fuel burning.
Some discussions with Dr. Spencer (oceans are the cause of the increase):
http://wattsupwiththat.com/2008/01/25/double-whammy-friday-roy-spencer-on-how-oceans-are-driving-co2/
and
http://wattsupwiththat.com/2008/01/28/spencer-pt2-more-co2-peculiarities-the-c13c12-isotope-ratio/
But please also read my comments!
Dr. Spencer and many other high profile skeptics accept the Mauna Loa data as reliable and trustworthy, he uses them without hesitation. See the article on his blog:
http://www.drroyspencer.com/2009/01/increasing-atmospheric-co2-manmade%e2%80%a6or-natural/
and my response, also published by him on his blog:
http://www.drroyspencer.com/2009/01/the-origin-of-increasing-atmospheric-co2-a-response-from-ferdinand-engelbeen/
Arctic ice core CO2 data (Greenland) are not reliable: much volcanic (Icelandic) acidic dust included, which produces CO2 in situ. And my take on SI data is the result of a discussion with Tom van Hoof, an author on SI data. I am still waiting for his comment on my remarks that SI data react on local CO2 levels (where we agree), and how that changed over time due to vegetation changes (not by global CO2, changes).
The local 1940-1942 historical CO2 levels of Giessen (Germany) were about 60 ppmv higher than the global ice core levels of the same age, while the modern Giessen/Linden measurements are 30 ppmv higher in average…
The entire set of carbon source and sink calculations are innumerate. Of course the error bars invalidate every calculation. Literally we don’t know if any of the sources or sinks are plus or minus. As you pointed out, you have to assume it from subtracting the stuff we put out from the stuff that’s measured by the Keeling franchise. Your argument that this net rise can’t be from the warming sea is based on extrapolating from Antarctic proxies for heaven’s sake. Why even assume that what happens in the Antarctic reflects the rest of the globe? Oh yes I remember – because CO2 is well-mixed.
As the Antarctic ice core measurements are an average of several years of CO2 levels, the measurements show the global average CO2 levels of these years. Even in the current increasing emissions period, one year average at the South Pole differs less than 5 ppmv from near the North Pole.
The individual CO2 flows have no importance at all for detecting the cause of the increase. You don’t need a detailed overview of all your ins and outs in bussiness over a day: counting what is in your cash register at the end of the day, every day again is enough to know if you have a loss or a gain…
The skepticism exists because everything done in this area is questionable. That a warming sea is pronounced to be a net sink, in contradiction of both nature and of other team arguments elsewhere, is only further evidence of just how easy it is for climateers to pull arguments straight out of their rear end and call it evidence
The CO2 measurements are reliable, I only could wish that the temperature measurements were that reliable and subject to the same rigorous calibration procedures. But it is proven – as far as science can prove something – that the oceans are a net sink for CO2. Simply because the increase in atmospheric CO2 is higher than the increase in partial CO2 pressure in the oceans due to higher temperatures.
Willis Eschenbach says:
Gavin points out a number of things in this regard here ( http://www.realclimate.org/index.php/archives/2010/01/unforced-variations-2/comment-page-2/#comment-152592 ):
(1) The AR4 results for future temperature trends used models that do not include carbon cycle feedbacks. Rather, they used various prescribed scenarios that specify the rise in greenhouse gases with time, which are in turn based on assumptions about emissions vs time, and the linkage between the two did not assume any carbon cycle feedbacks. (Of course, any given scenario for a rise in greenhouse gas concentrations could be consistent with a variety of different scenarios for a rise in emissions coupled with different magnitudes of carbon cycle feedback.)
(2) The models that predict the carbon cycle feedbacks do not generally show any significant change in airborne fraction during the 20th century. So, it is incorrect to claim that Knorr’s results show the “model results are hogwash”. Unfortunately, we cannot yet test the predictions of these carbon cycle feedbacks in the models. (Or, at least, a good direct test has not been thought of yet, AFAIK.)
(3) In the carbon cycle model, the magnitude of the change due to changes in the airborne fraction by 2100 varies from an extra 20 to 220 ppmv over the nominal ~800 ppmv for SRES A2 (one of the moderately high emissions scenarios, I believe). So, the contribution of the predicted carbon cycle feedbacks to the CO2 level above the ~280ppm pre-industrial baseline ranges from ~4% to ~30%. I.e., it ranges from a fairly trivial contribution to a decent one, but still a minority of the effect.
Michael J. Dunn (08:54:58) : please could you email me, thanks.
Ferdinand Engelbeen (12:37:24)
“the increase in partial CO2 pressure in the oceans due to higher temperatures”
Now I’m confused – higher sea water temperature means MORE dissolved CO2? Does this mean that Le Chatelier’s principle is wrong?
(Le Chatelier’s Principle states that a dissolved gas (carbon dioxide in this case) always becomes less soluble with increasing temperature. One can testify to this from experience that much more gas is released from a can of soda that is opened when it is warm rather than when it is cold.)
phlogiston (13:29:42):
I believe that was a typo on Ferdinand’s part and he meant to say
Or, maybe an even better statement would have been, “Simply because the increase in the partial CO2 pressure in the oceans due to the increase in atmospheric CO2 is higher than the decrease in partial CO2 pressure in the oceans due to higher temperatures.”
Scott:
In my previous post, I said “As for your ocean calculation, I can’t tell you exactly what is wrong with it at the moment but I would suggest that you read a textbook or article that goes through such calculations.” Actually, one thing that may be part of the problem is that the oceans are best modeled as a mixed layer that has about the same amount of carbon as the atmosphere and then the deep ocean which has an amount that is about 2 orders of magnitude larger…and the exchange between the surface water and the deep ocean is pretty slow, so it is part of what forms the bottleneck (although, as I noted previously, I think the rate at which one can get calcium carbonate into the ocean to buffer the added carbonic acid due to the higher partial pressure of the CO2 gas is also an important piece of the puzzle).
Joel Shore (13:08:22)
Joel, as always, a pleasure to hear from you. For those who don’t recognize the name, Joel is a scientist (a physicist I believe?), and one of the few AGW supporters with the courage to post here under his own name. That gets my respect even though we often disagree. Onwards to the issues.
I am surprised that after the CRU emails you post a link to RC. I wouldn’t up their page count by one if you paid me. The site is a shill for Michael Mann, who showed himself in the emails to be a man who is willing to do lie, cheat, and steal to get his point across whether it is true or not. RC ruthlessly censors scientific dissent, and your citing them gives that anti-scientific view credence. You lower your scientific crediblility immensely by any association with them.
As far as I understand the scenarios, this is not true. The scenarios specify the rise in emissions, not the rise in GHGs, which is left to the models to calculate. If I’m wrong, please provide a cite.
That was exactly my point. The IPCC says that climate change causes a change in airborne fraction, viz my citation above:
The IPCC also is very emphatic that there was significant climate change during the 20th century. And the log change in CO2 since pre-industrial levels is about half of that from a doubling of CO2. But we have seen no change in atmospheric fraction … connect the dots.
Having said that, however, I was wrong to say that the study showed the model results were hogwash. Foolish me, I didn’t note the huge confidence interval of the study results, my bad. The 95% confidence interval for the study results is a change in airborne fraction of -2.0% to 3.4% …
I fear I lost you here, likely my fault. What is the source of your figures for the “carbon cycle model”?
In any case, as you say, has been no change in the airborne fraction resulting from a change from 280 ppmv pre-industrial to the present 390 ppmv. So the entire 220 ppmv of change due to airborne fraction variation you reference above must occur between now and 800 ppmv, not between pre-industrial ppmv and 800 ppmv. This makes the high end estimate of 220 ppmv 54% of the change between now and 800 ppmv … which is not “a minority of the effect”.
My best to you,
w.
Michael J. Dunn says:
That residence time is about in-line with other estimates for atmospheric CO2. However, that is not the relevant time for estimating the time it takes for a pulse of fossil fuel CO2 in the atmosphere to disappear. I am reposting below something that I posted on another thread explaining this:
On the issue of residence times, I was just re-reading the relevant section of “Global Warming: The Hard Science” by L.D. Danny Harvey ( http://books.google.com/books?id=8zBRAAAAMAAJ ). He calculates a residence time on the order of 5-6 years for the atmospheric reservoir. Here is what he then has to say (pp. 20-21):
Thanks for a response Joel. What you describe accounts for no uptake, that’s 2 months away in these areas. But what generates it? No one lives there to speak of, (ref. pop. density, not the good folks who do live there), so what is the source? It appears to suddenly bloom up in a huge, largely uninhabited, non-industrialized, frozen area. Any ideas?
I think its important never to forget the following sentence by Michael Hulme;
“We will continue to create and tell new stories about climate change and mobilize them in support of our projects” ….
According to IPCC’s data distribution center, they use CO2 concentrations in their projections. See http://www.ipcc-data.org/ddc_co2.html
Steve Keohane (14:14:44):
Well, CO2 is pretty well-mixed in the atmosphere (not perfectly so…especially between hemispheres, but pretty good), so I don’t think you should think of these variations as being due only to local sources. It will have pretty good communication with a large fraction of the Northern Hemisphere.
Willis:
Thanks for your kind words. I am indeed a physicist.
To each his own. You have directed me before to the website of the Senate Minority Committee on the Environment, basically in the hands of Sen. James Inhofe and Marc Marano (before he moved on to start ClimateDepot). I am willing to bet you a substantial amount of money that any survey of climate scientists would find a substantially larger portion who think that Gavin Schmidt and Michael Mann are trustworthy on the science than who think that James Inhofe and Marc Marano are.
I don’t think what you say and what I say are necessarily in conflict. I agree that the scenarios specify emissions but I think the point is that the way the models have generally converted this into CO2 concentrations was not with elaborate carbon cycle models that included feedbacks, so my understanding was that the models would at least roughly assume that the airborne fraction would remain constant. (I admit that I am not exactly sure if that is their precise assumption or exactly how close to it their assumption is…Something worth looking into.)
Well, the climate change that we have seen thus far is not that large compared to what we might expect to see. The log-change for CO2 is about 46% of a doubling but there have also been increases in aerosols and the climate system has not yet fully equilibrated to the changes. Furthermore, the various feedbacks are not all due to the warming climate. There are also issues of things, like the growth in biomass with increasing CO2 concentration, tending to saturate after a while.
As you note, on top of that are the uncertainties in the Knorr results.
I was paraphrasing Gavin who in turn gives as his source IPCC AR4 10.4.1 (I assume he means the WG-1 report).
Well, okay, I suppose you could do it from the ~385 ppmv baseline if you want. However, I don’t think you have done this calculation quite correctly since, as I understand it, the additional 220ppmv would be over and above the 800 ppmv, so the final total would be 1020 ppmv instead of 800 ppmv. So, we would be talking about ~35% of the difference between 385ppm and 1020ppm coming from the increase in airborne fraction.
Wansbeck (05:31:29) :
Some time ago I remember seeing a similar map showing NOx concentrations. The industrialized regions were immediately obvious.
The CO2 map shows no increased concentration over industrialized regions. Even with today’s increased CO2 levels natural sources appear to dominate.
Does this not suggest that today’s CO2 levels are determined by nature and not mankind??
No it doesn’t suggest it at all, for two reasons.
NOx and SOx are produced largely by man in industrial areas. That means the initial concentrations in particular areas are strikingly higher. That makes it different to COx, which is produced all over the globe to start with.
More importantly, NOx and SOx are highly water soluble. They are come down as “acid rain” in a way not even remotely duplicated by COx, which is barely water soluble.
Combine the unequal production with the half-life in the atmosphere and you get a very uneven spread across the globe.
COx is resident for long enough to be widely and evenly dispersed. Those of you who don’t like this fact ought to move on to other areas of concern because you are wasting your time with this one. (Note: I’m a sceptic, not a warmista, but not on this.) The amount of CO2 in the atmosphere is increasing, what needs to be determined is the reason and the effects.
phlogiston (13:29:42) :
Ferdinand Engelbeen (12:37:24)
“the increase in partial CO2 pressure in the oceans due to higher temperatures”
Now I’m confused – higher sea water temperature means MORE dissolved CO2? Does this mean that Le Chatelier’s principle is wrong?
(Le Chatelier’s Principle states that a dissolved gas (carbon dioxide in this case) always becomes less soluble with increasing temperature. One can testify to this from experience that much more gas is released from a can of soda that is opened when it is warm rather than when it is cold.)
Except of course that the pCO2 in the atmosphere is increasing independently so that the equilibrium temperature of the ocean will increase.
why not discuss how many bb’s can be stacked on top of each other since no person has proven that an increase in co2 causes an increase in temperature.
Kudos to Rhinebeck sophomore Michelle Dewkett for speaking out against the school district for only showing Al Gore’s Am Inconvenient Truth and demanding that they follow their own policies and present a balanced view. Rhinebeck is my home town and I have posted this on 5 of my sites including the Rhinebeck blog.
http://www.boudica.us/rhinebeck-blog.html.
Comments are overwhelmingly in support of Michelle. Visit and post a comment. Let’s hope she starts 2010 off with some fireworks in Rhinebeck.
Bob A.
[youtube=http://www.youtube.com/watch?v=Y5YnZKwgjR4&color1=0xb1b1b1&color2=0xcfcfcf&hl=en_US&feature=player_embedded&fs=1]
davidc (10:31:19) :
[responding to my earlier post at (08:54:58)]
“It’s still available at
“http://en.wikipedia.org/wiki/Carbon-14
“It looks to me that the half-life is around 70 yr (so e-folding ~50 yr), but that’s for CO2 in the upper atmosphere. It would be a lot shorter for CO2 produced at ground level where the major sinks are.”
Thanks for the pointer (bless you) and the correction. The human memory is frail.
I crudely plotted the 5-year data points and estimated the e-folding time from the mean initial slope (reference level is 100%, since C-14 is constantly produced by cosmic rays) as being about 29.4 years. This would make the half-residence time about 20 years, which is consistent with the graph.
I don’t understand why you ascribe these concentrations to the upper atmosphere. The data from which the graph was constructed were taken at ground level.
“John Doe (14:21:21) :
According to IPCC’s data distribution center, they use CO2 concentrations in their projections. See http://www.ipcc-data.org/ddc_co2.html”
Ok… but they say they got time series for concentrations of CO2 through running Carbon Cycle models:
“For each of the illustrative and marker emissions scenarios, CO2 concentration projections calculated by two different carbon cycle models were reported in IPCC (2001) and used as the bases …”
They then link to here:
http://www.ipcc.ch/ipccreports/tar/wg1/122.htm#box37
where they “explain” their CC models. I don’t really understand what they’re trying to do here – i would think that the only sensible option would be
to run GCM and CC in parallel but here i get the impression that they first run a CC and then feed the CO2 concentration time series into the GCM.
I think on this page two snippets are important: They say:
“In addition to varying the climate sensitivity (1.5 to 4.5°C), …”
and
“The effect of increasing climate sensitivity to 4.5 °C (increasing the climate feedback)…”
So they seem to assume a climate sensitivity for the doubling of CO2 of at least 1.5 deg C. Unfortunately they don’t say here what feedback factor range they assume. Could be from 1 to 3 , from 2 to 6, from 3 to 9. Well why should they tell us mere mortals. Maybe somewhere else in their paper mountain they say it.
The funny thing is in my comment at
http://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/#more-12889
DirkH (16:28:20) :
i computed for a rise in incoming energy of 0.85 W/m^2 a rise in surface temp of 0.15 deg C. As small changes are near-linear a rise of 4 W/m^2
(the usually assumed radiative forcing effect of a doubling of CO2) would give approx. 0.75 deg C. But the IPCC computed their models with an assumption of a climate sensitivity (incl. the assumed water vapor feedback) of 1.5 to 4.5 deg C. So did they implicitly assume that water vapour feedback at least doubles the effects of CO2?
I should add that in my computation (0.85W/m^2 more–> 0.15 deg C temperature rise) i did not assume any climate sensitivity but just applied the Stefan-Boltzmann-Law.