How can anyone question man's significant role in global warming?

[Skyhunter]

Okay, so whenever:
which doesn't mean that you can interpret it as unpreceded warming in the Holocene. for that you'd need to have other proxies.

Are you intentionally mis-characterizing the paper?

Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged 18O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at least the last 2 millennia. Second, the continuing retreat of most mid- to low-latitude glaciers, many having persisted for thousands of years, signals a recent and abrupt change in the Earth’s climate system. Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. This abrupt event, 5,200 yr ago, was widespread and spatially coherent through much of the tropics and was coincident with structural changes in several civilizations. These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr. The ongoing global-scale, rapid retreat of mountain glaciers is not only contributing to global sea-level rise but also threatening freshwater supplies in many of the world’s most populous regions.

So what else is new about South America and the Holocene Therman Optimum?

http://tinyurl.com/ezvgx

Received 28 January 1992; accepted 25 May 1992. ; Available online 14 April 2003.

Not exactly new, but still relevant. Abstract does not contradict Thompson's article.

http://tinyurl.com/lcnmy
,

Again this abstract does not contradict Thompson.

http://tinyurl.com/gaxun

Nor does this one.

Furthermore, Thompson could have cross checked the literature about the Medieval Warm Period in South America, being warmer than today or not and he could have found:

Rein B., Lückge, A., Reinhardt, L., Sirocko, F., Wolf, A. and Dullo, W.-C. 2005. El Niño variability off Peru during the last 20,000 years. Paleoceanography 20: 10.1029/2004PA001099.

The authors derived sea surface temperatures from alkenones extracted from a high-resolution marine sediment core retrieved off the coast of Peru (12.05°S, 77.66°W). The results indicated that the warmest temperatures of the past 20,000 years occurred during the late Medieval Period (AD 800-1250), and that they were about 1.5°C warmer than those of the Current Warm Period..

http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/studies/l1_perushelf.jsp

Here you are being particularly misleading. That is not a quote by the authors you cite. It is a description of their paper from a non objective and questionable source.

and

L Pérez-Cruz, 2006; Climate and ocean variability during the middle and late Holocene recorded in laminated
sediments from Alfonso Basin, Gulf of California, Mexico Article in Press, Quaternary Research Corrected
Proof -
Abstract
A laminated sequence (core BAP96-CP 24°38.12N, 110°33.24W; 390 m depth) from the Alfonso Basin in Bay of La Paz, southern Gulf of California, contains a record of paleoceanographic and paleoclimatic changes of the
past 7900 yr.

... Proxies indicate a warm scenario and the dominance of the Equatorial Surface Water in the Alfonso Basin from 2400 to 700 cal yr BP, suggesting the intensification of ENSO cycles.

suggesting that the current warm period is nothing unprecedent at al.

And since you posted no link I have not read this paper, therefore I have no idea what it suggests.

I keep wondering how people can think that man has a significant role in global warming.

Well since the glaciers, which are the source of the cores that provide evidence for the temperatures of these warming periods are themselves melting, I find little difficulty believing it. If the MWP or the Holocene thermal maximum were warmer than today, those glaciers would have melted then as well.

Suppose that we can proof within a three sigma certainty that global CO2 levels were higher than today in the timeframe 1938-1949 and subsequently dropped against the increasing anthopogenic production, what would that say about the current climate paradigms?

But you cannot prove that, because there is no evidence other than atmospheric CO₂ measurements that have been discredited and stomata in conifers. A technique that holds promise for the future, but at this time has a high degree of uncertainty.

 

[Andre]

Thanks Skyhunter for your excellent demonstration of how the warmers fight way below the belt, your post is most exemplary of how it works:

Are you intentionally mis-characterizing the paper?

Polarizing a neutral sane scientific method (reproduction of results) into a personal attack since it implies: "are you a criminal" (ad hominem) and "how dare you attacking such a authority".

Obviously all the other remarks are doing the same. I hope that the intelligent readers here see trought the trick. I'm not going to lower myself into defending that I'm not a criminal. And you can think winning the discussion here, but the evidence remains firm that there was a distinct HTM and MWP in South America. There is one remark though:

because there is no evidence other than atmospheric CO2 measurements that have been discredited

Please show the evidence. So what is discredited? Do show, on what scientific grounds, those measurements have been discredited. After all, why should I allways need to carry the shiploads of evidence, why may adversaries always say anything they want?

 

[Andre]

Here, let me help, here are the discrediters:

G. S. Callendar, “Variations of the Amount of Carbon Dioxide in Different Air Currents,” Quarterly Journal of the Royal Meteorological Society, vol. 66, No. 287, October 1940, pp. 395-400

Callendar, G.S. (1938). "The Artificial Production of Carbon Dioxide and Its Influence on Climate." Quarterly J. Royal Meteorological Society 64: 223-40

Callendar, G.S. (1958). "On the Amount of Carbon Dioxide in the Atmosphere." Tellus 10: 243-48.

Keeling, C.D. 1960. The concentration and isotopic abundance of carbon dioxide in the atmosphere. Tellus 12:200-203.

Keeling C. D., 1958. The concentration and isotopic abundances of atmospheric carbon dioxide in rural areas, Geochim Cosmochim Acta. 13: 322-334.

Now let's scrunitnize why exactly those discredited values were wrong.

 

[Andre]

Here, let's even make it easier, here is a zipped scan of the key document, Callendar 1958

http://home.wanadoo.nl/bijkerk/Callendar-1958.zip

 

[Mk]

Are you intentionally mis-characterizing the paper?

Really, it doesn't matter if one does or does not. The only issue I see is respect, but science doesn't care about respect.

"The improver of natural knowledge absolutely refuses to acknowledge authority, as such." -- Thomas H. Huxley, on skepticism

 

[Skyhunter]

From your earlier post Andre, characterizing the Thompson article as;

an cleary coordinated attempt to bury the Holocene Thermal Optimum

But this is what the article says about the Holocene.

The third line of evidence for abrupt tropical climate change comes from a rooted, soft-bodied plant deposit discovered after it was exposed along the west-central margin of the rapidly retreating Quelccaya ice cap. The plant was identified as the wetland plant Distichia muscoides (Juncaceae), a dioecious mat- or cushion-forming plant (Fig. 7) that is well adapted to harsh diurnal freezing and thawing and often reaches the altitudinal vegetation limit, which is 5,100 m above sea level around the Quelccaya ice cap. The average of eight accelerator mass spectrometry 14C dates from two different laboratories places the calendar age of this plant deposit at 5,138 (±45) yr B.P. (Table 1). The recently exposed plant deposit provides strong evidence that temperatures were warmer in this region before 5.1 thousand years (ka) B.P. and that the current retreat of Quelccaya is unprecedented for the last 5 millennia.

Their conclusion based on the plant deposits exposed by the retreating glacier is evidence that during the Holocene, at the Quelccaya ice cap, it was at least as warm as it is now. Those plants don't grow on glaciers, so the glacier wasn't there 5138 years ago. And lacking evidence of any growth for the past 5 millenia, it would be safe to assume that the glacier has likely been there for 5000 years. And now it is melting. In fact glaciers are melting all over the world at astonishing rates.

I am sorry if you thought I was implying that you were deliberately mischaracterizing the article. And I certainly did not call you a criminal.

However, since the article does not dispute the warming during the Holocene. I wonder why you think it does?

Since Thompson et al did use other proxy data to support their conclusions, to imply otherwise is a mischaracterization.

I was simply asking if you were doing it intentionally.

I found nothing out of the ordinary with any of the literature you provided, nor on any other papers I found on the internet. Nowhere could I find a reading of 438ppm.

If you wish to refute something specific I would be happy to explore it with you. But if you want to joust with windmills, I will have to pass.

 

[Andre]

I'm a bit clueless about Thompsons glacier and I fail to see how his isotopes can say anything about the MWP and the HTM seeing the large unpredicable deviations of temperature in isotopes. So why is it here in the first place? anyway,

I found nothing out of the ordinary with any of the literature you provided,

Well how about the selection -data mining-criteria?

nor on any other papers I found on the internet. Nowhere could I find a reading of 438ppm.

Not everything is online and some libraries should be able to produce the relevant studies. I would recommend:

Duerst U, 1939, “Neue Forschungen über Verteilung und Analytische Bestimmung der wichtigsten Luftgase als Grundlage für deren hygienische und tierzüchterische Wertung,” Schweizer Archiv fiir Tierheilkunde, vol. 81, No. 7/8, August 1939, pp.305-3 17

Haldane, JBS 1936 Carbon Dioxide Content of Atmospheric Air, Nature, Apr 4 pp 575

Hock et al. 1952; Composition of the ground-level atmosphere at Point Barrow (Alaska) Journal of meteorology, Vol 9, 1952, S. 441

Kreutz W, 1941, Kohlensäure Gehalt der unteren Luftschichten in Abhangigkeit von Witterungsfaktoren, Angewandte Botanik, vol. 2, 1941,
pp. 89-117

Misra RK, 1950, Studies on the Carbon dioxide Factor in the Air and Soil Layers near the Ground, Indian Journal of Meteorology and Geophysics Vol I No4 pp275-286

So I plotted all available data of free air CO2 including back scans of graphs on a monthly average basis http://home.wanadoo.nl/bijkerk/fortiespike.GIF . And I accept certain accumulating error of some dozen ppmvs but even then, there is something to discuss. Anticipating some comments, I will wait elaborating.

 

[Skyhunter]

http://www.warwickhughes.com/agri/BeckCO2short.pdf is a short summary of the pre 1957 CO₂controversy, by those arguing against AGW.

They argue that some of the chemical measurements taken before 1961 are being ignored by Keeling, Callendar and the IPCC because these measurements don't fit AGW.

Looking at the data I must say that I agree with Keeling, Callendar, and the IPCC. Most, if not all climate scientists agree that the measurements made after 1957 using NDIR spectroscopy at Mauna Loa, are the most accurate and representative measurements of atmospheric CO₂ ever taken. These measurements do not show the wild fluctuations that are so prevalent with the measurements made using the chemical methods prior to 1957.

If you look at the two graphs, (Fig. 1 pg 4, Fig. 2 pg 5) the trend is stark and obvious.

It is not that the data does not fit a theory. It is that the data does not fit with what we now know about the physics of CO₂ concentrations in the atmosphere. What was a common trend for 150 years is no longer observable now that scientists are using methods that are ~30 times more accurate.

Are we to assume, that when we gained the ability to measure atmospheric CO₂ accurately, it just stopped fluctuating wildly and coincidentally coincided with levels that are recorded in the glaciers?

If global CO₂ concentrations were as high as 420 PPM, the upper ocean would become much more acidic as the CO₂ was absorbed into the oceans in the form of carbonic acid. The effects of ocean acidification would last for tens of thousands of years.

http://www.physorg.com/news11008.html

Barring some new evidence that CO₂ levels do fluctuate wildly, I feel confident in ignoring the pre 1957 measurements that showed high levels of CO₂, especially since there were other measurements taken pre 1957 that fit with modern, more reliable evidence.

In short, we now know that global atmospheric CO₂ content does not fluctuate wildly.

In order to question man's significant role, one needs to deny overwhelming evidence.

 

[Andre]

Nice circular reasoning Skyhunter.

For instance:

Callendar "knows" that the anthropogenic CO2 production causes an increase of the atmospheric CO2.

He cherry picks the few data that would 'proof' that claim, and refuting the majority of data without any substantiation (for instance for being of more than 10% off his selected base line).

So now we "know" empirically that background CO2 level in the atmosphere reacts inert. "In short, we now know that global atmospheric CO2 content does not fluctuate wildly." So we cannot accept rates off changes of some 20 ppm per year, suggested by the rejected measurements of Buch (Ireland) Duerst (Switserland), Kreutz (Germany), Misra (India) and Hock et al (Alaska).

But we know that because Callendar had ordered it so to be, closing the circle. Why would CO2 not be able to change with those rates?

http://www.carleton.edu/departments/geol/DaveSTELLA/Carbon/carbon_intro.htm

Check fig 7 for 1994, Fossil fuel burning was 5GtC/yr, release of CO2 by warm ocean waters was 90 GtC/yr, uptake of CO2 by cold surface water was -90GtC/yr, downwelling of cold surface water moves 96.2 GtC/yr, upwelling at the equator 105,6 GtC/yr etc etc

We could consider the atmosphere a very tiny overflow buffer of CO2 for the oceans. Change anything significant in the oceans and your carbon dioxide balance budget can change dozens of GtC/year, more than enough to have an annual fluctuation of 0,000020 volume parts.

Anyway, there is a pet mechanism that could create havoc in the oceans every so often. Apparantly this happened on a large scale 14,500 and 11,600 years ago and on much smaller scales around 350AD, around 1830AD and around 1940AD apparently with little action in between.

 

[Andre]

I understand that's difficult to accept the high measurements without access to the actual references.

The most comprehensive of those sampling was done by Kreutz (1941) in the weather station just outside the (then relatively small) town of Giessen, Germany. His report in German is a masterpiece of advanced heavy literature and hence difficult to read. Therefore an impression of the contents:

His objective was to find correlations and dependencies of CO2 with weather phenomenons. For that he started continuous sampling, first about every two hours to establish a diurnal pattern and later three times a day for continuation. Sampling was done on four different heights simultaneously, ground level, 0.5 meter 2 meters and 14 meters (on the observation tower) and it started as of August 1939, his report includes sampling up to Jan 1941, despite the continuation of sampling there was never a second report.

Kreutz did some interesting discoveries. The average CO2 levels were highest at the 14 meters sampling location, even slightly higher than at ground level. The two meter point gave the lowest CO2. Correlating these series he found that ground level showed the highest diurnal variation, 14 meters the lowest, which made him conclude that the soil was a clear CO2 source as were the “industries and the cities” apparently at the 14 meter level. For the rest he struggled with temperatures, moisture, inversions, precipitation forms, etc, etc, but the awkward spike, centred on august 1940, spoiled everything. Most notably is the role of the wind. CO2 levels were highest with westerly winds whereas strong winds seem to either decrease or increase the CO2 level at random. But most noteworthy his overall average value was about 430 ppm and he was the first to realize that the mainstream value of 0.03% was actually too low.

To validate Kreutz observations on the anthropogenic factor, a number of evolutions is currently taken place. For a general assessment of the anthropogenic factor in cities, there are a few studies available which show consistently average values about 30 ppmv higher in downtown metropolises compared to the standard of Mauna Loa. A second factor is the assessment of the values of the 6-7 modern measuring stations in Germany in rural sites against Mauna Loa, to see if the background CO2 level is much different (it isn’t). A third assessment would require a detailed historical reconstruction of the anthropogenic CO2 production around Giessen in that time. After all, there was a war going on. Preliminary result is only the proximity of a railway (500 meters) but then again the reconstructed 1940 fossil fuel consumption of Germany was only a fraction of today.

The conclusion would be that no matter what you try and which error margins you want to apply, the back ground natural CO2 level in 1940 was higher than today. Of course the awkward August spikes beg for an explanation. Kreutz did not mention any increase in human activities in that period and suspected an unusual soil production. There is an interesting riddle to solve. Suggestions have included possible contamination of the chemicals needed for titration and increased war activities. It was the time of the battle of Britain of course, some 800km away but nowadays a multitude of fuel is consumed by the local commercial airlines and no trace of a spike like that.

And Callendar 1958? He probably had never heard of Kreutz when he cherry picked his CO2 values let alone that he was willing to decipher the text, then again, he would have rejected the result anyway because it exceeded his standard of accepting only values with less than 10% aberration. But if he would have been a little bit more objective, we may not have had the global warming hype of today.

 

[Andre]

incidentely, http://home.wanadoo.nl/bijkerk/fortiespike.GIF is a plot of the mentioned publications with all values avaible reduced to monthly averages.

 

[Skyhunter]

incidentely, http://home.wanadoo.nl/bijkerk/fortiespike.GIF is a plot of the mentioned publications with all values avaible reduced to monthly averages.

Sorry Andre, but I am not going to believe that modern CO₂ science is being conducted by incompetent scientists. If the atmospheric CO₂ content fluctuated wildly, then we would have observed this over the last 50 years.

The data does not fit what has been observed since 1957.

So.

Either the old data using chemical analysis is wrong. or...

The new data using NDIR spectroscopy is wrong. or...

There is a giant conspiracy to force civilization to stop practicing necromancy by burning their ancestors in the form of fossil fuels.

 

[Andre]

Sorry Andre, but I am not going to believe that modern CO₂ science is being conducted by incompetent scientists. If the atmospheric CO₂ content fluctuated wildly, then we would have observed this over the last 50 years.

Why? There was also neither fluctuation between about 1885 and 1933 nor after 1957 in which time the measurement with identical the same *wrong* chemical analysis showed nevertheless "acceptable" values around 300ppm

The new data using NDIR spectroscopy is wrong. or...

Why? the last chemical measurements agreed nicely with the spectroscopic results.

There is a giant conspiracy to force civilization to stop practicing necromancy by burning their ancestors in the form of fossil fuels.

Well as far as I'm concerned, the whole billion dollar climate hype business is also based on the judgement of a single man, rejecting CO2 data already in 1938 that did not suit his purpose, without any critical review.

 

[Skyhunter]

Why? There was also neither fluctuation between about 1885 and 1933 nor after 1957 in which time the measurement with identical the same *wrong* chemical analysis showed nevertheless "acceptable" values around 300ppm



Why? the last chemical measurements agreed nicely with the spectroscopic results.



Well as far as I'm concerned, the whole billion dollar climate hype business is also based on the judgement of a single man, rejecting CO2 data already in 1938 that did not suit his purpose, without any critical review.

I have not seen any chemical measurements after 1957. As far as I know no one uses the chemical method anymore. The fluctuations between 1885 and 1933 were not as erratic as before and after, however they did vary as much as 30ppm from year to year, considerably more than the measurements taken after 1957; and the ice cores, do not match the readings for that period.

 

[Andre]

I have not seen any chemical measurements after 1957. As far as I know no one uses the chemical method anymore.

Only at schools out of curiosity. Seems to work quite nicely.

The fluctuations between 1885 and 1933 were not as erratic as before and after, however they did vary as much as 30ppm from year to year, considerably more than the measurements taken after 1957;

Yes and one should wonder, if the chemical samplings before 1933 and after 1955 are in the expected range, why was every measurement with the same method higher anywhere? Do we accept that all those samplers went nuts collectively or that we are confronted with a phenomenon that is not understood yet?

and the ice cores, do not match the readings for that period.

Ice cores with the first 80-100 meter open firn with hundreds to thousends years of free ventilation/difussion, cannot register decadal scale spikes

 

[Skyhunter]

Yes and one should wonder, if the chemical samplings before 1933 and after 1955 are in the expected range, why was every measurement with the same method higher anywhere? Do we accept that all those samplers went nuts collectively or that we are confronted with a phenomenon that is not understood yet?

The samplings are not indicative of global atmospheric CO₂. I do find them interesting, but not particularly relevant the debate about AGW.

Old and somewhat questionable science is not sufficient evidence to refute AGW. From what is now known about atmospheric CO₂ physics, such erratic fluxes are not possible. If such fluxes occur and can be observed in the future, without leaving other proxy evidence, then these samplings will add a new dimension to our understanding of the carbon cycle. Until such time it is right to attribute these readings to regional anomalies or sampling errors.

Ice cores with the first 80-100 meter open firn with hundreds to thousends years of free ventilation/difussion, cannot register decadal scale spikes

Now why would they not?

If the CO₂ concentration was at 430 ppm for a decade, it would increase the concentrations in the lower firn (80-100 meters). So the ice that formed at these depths in the 1930's and 40's would register a higher concentration of CO₂.

There would be a smoothing of the spike, but a spike of that magnitude would leave a trace in the ice core, as well as other proxy evidence.

What I find more interesting than old air samples is this;

Carbon Cycle Budget for Anthropogenic Effects

Sources:

Fossil Fuel Burning & Cement Production 5.5±0.5 GtC/yr
Forest Burning & Soil Disruption 1.6±1.0 GtC/yr
Total Anthropogenic 7.1±1.1 GtC/yr


Sinks:

Storage in Atmosphere 3.3±0.2 GtC/yr
Oceanic Uptake 2.0±0.8 GtC/yr
Boreal Forest Regrowth 0.5±0.5 GtC/yr
Missing Sink 1.3±1.5 GtC/yr

GtC = Gigatons of carbon = 109tons data from IPCC, 1996

http://www.carleton.edu/departments/geol/DaveSTELLA/Carbon/carbon_intro.htm

Where is the unaccounted for carbon sink?

When will it and the other sinks become saturated?

As the oceans warm their ability to absorb CO₂ decreases.

How will this effect global temperatures?

 

[Andre]

The samplings are not indicative of global atmospheric CO₂. I do find them interesting, but not particularly relevant the debate about AGW.

Why not? So which sampling is? What is the selection standard. And how objective would that criterium be. It's not like the inverse proportionality between the attractiveness of the facts and the acceptance standards, is it? If facts are unattractive we refuse to accept them.

Old and somewhat questionable science is not sufficient evidence to refute AGW.

Since when is there a "best before..." date, or should studies also include a sentence: "these data are only valid until Nov 2th 2006?" if you want to question the science, you read the papers, reproduce the methods that were used and calibrate the results with modern methods. And remember, they were first, so the onus of falsifying their results is with the challenger.

I wonder what results will be there for the reproduction of those studies that produced low CO₂ measements consisently. I read that some used sulpher acid to dry out the air. I wonder what that does to the CO₂ contents of the air.

From what is now known about atmospheric CO₂ physics, such erratic fluxes are not possible.

No that's a circular reasoning, we observe flat CO₂ rates in the ice cores, rejecting data that show much higher rates, so we conclude that CO₂ rates of changes cannot be big and we compute a resident time of 100 years for CO₂ empirically, based on our selective data. In reality the annual balanced exchange rate between oceans and atmosphere are in the order of magnitude of 100 GTC. Change something in that balance and the accumulation rate of CO₂ in the atmosphere may be surprising. Actually there are several of that kind of CO₂ spikes in the past recorded in fossil leaf stomata proxies.

If such fluxes occur and can be observed in the future, without leaving other proxy evidence, then these samplings will add a new dimension to our understanding of the carbon cycle.

We can anticipate that by returning to the scientific method and accept sound observations that do not fit our world view, even if it refutes the misunderstandings about the greenhouse gas mechanism.

Until such time it is right to attribute these readings to regional anomalies or sampling errors.

How many samples are required and how many regions to realize that there is more to it?

Now why would they not?

If the CO₂ concentration was at 430 ppm for a decade, it would increase the concentrations in the lower firn (80-100 meters). So the ice that formed at these depths in the 1930's and 40's would register a higher concentration of CO₂.

Well, there was an issue with CO₂ in firn and ambient temperatures. Since the Greenland Ice cores did show strange spikes and consistent CO₂ values of over 300ppmv in contrast with the Dome C, Vostok Antarctic proxies, it was declared void, probably contamination, chemical reactions and extramorphes, bacterea algea, etc due to the higher temperatures (ca -33C) compared to the Antarctic domes (-45-60C). But the firn closure rate of those is far to low (mm to cm per year) to register any spike. So we found a high accumulation core in West Antarctica, Siple Dome with meters per year, which shows a neat CO₂ proxy fitting exactly to our perceptions...

However the firn temperature of ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsi0098_severinghaus/firn_temps.txt is much higher than Greenland. So, how is that for selective acceptance standards? How about accepting both Greenland and Siple Dome, and we have a problem to solve; or neither Greenland and Siple Dome, and we have no data anymore? The latter is probably more correct. As Severinghaus et al has figured out something out about al kind of fractionation processes going on in the firn, we have probably seen only the beginning. For instance, how about thermal and molecular fractination of CO₂ in relation to O₂ and N₂ in the diffusion processes between firn and the atmosphere?

The advantage of not being steered by the AGW paradigm is that you can wonder freely about surprises in nature, instead of ignoring them or declaring them void. But I agree that the 1935-1945 CO₂ spike should be visible in more proxies. We’re working at d13C in tree rings currently and perhaps we can find some high resolution coral of that time

 

[Bystander]

(snip)What I find more interesting than old air samples is this;
http://www.carleton.edu/departments/geol/DaveSTELLA/Carbon/carbon_intro.htm

"Carbon Cycle Budget Estimates "

Where is the unaccounted for carbon sink?

When will it and the other sinks become saturated?

"Where ... ?" With all the other unaccounted for fluxes. "When ... ?" Never. Conservation of mass takes care of that concern.

As the oceans warm their ability to absorb CO₂ decreases.

The oceans already contain more CO₂ than they would if in equilibrium with the atmosphere; they are a dynamic, biologically driven sink for carbon. The capacity of the oceans to sink C depends upon biological productivity --- increase that, and reduce atmospheric CO₂; reduce that, and increase atmospheric CO₂.

How will this effect global temperatures?

It won't.

 

[Skyhunter]

The advantage of not being steered by the AGW paradigm is that you can wonder freely about surprises in nature, instead of ignoring them or declaring them void. But I agree that the 1935-1945 CO₂ spike should be visible in more proxies. We’re working at d13C in tree rings currently and perhaps we can find some high resolution coral of that time

Looking forward to hearing about the results.

 

[Sinimod]

Andre,

Perhaps you could provide any links to stomatal evidence for these huge CO2 fluctuations. I would think that that shouldn't be difficult since stomatal data has been used all the way back to the Younger Dryas.

 

[Andre]

Sure,

http://www.bio.uu.nl/~palaeo/Personeel/Lenny/artikellinks/full.pdf

fig 5.4 pag 61 and page 90

 

[Sinimod]

Sure,

http://www.bio.uu.nl/~palaeo/Personeel/Lenny/artikellinks/full.pdf

fig 5.4 pag 61 and page 90

It seems there is a discrepancy between the Kurschner and Visscher graphs and data of Kreutz for CO2 levels in the 1940s. In addition, there is no mention in the text provided in the above link of CO2 concentrations reaching 430 ppmv in the 1940s. In fact, their data substantiates the belief that CO2 levels rose from approximately 290 ppmv at the outset of the industrial revolution to current levels of approximately 375. Granted, Kurschner and Visscher graphs show a spike to 390 ppmv, but that controversy must still be worked out.

 

[majin]

thanks amazon

I think we all owe a great deal of thanks:!)
to our friend the amazon forest...does anyone know why.....hmmm

 

[Mk]

It supplies firewood and housing to a lot of people that live in it?

 

[Andre]

It seems there is a discrepancy between the Kurschner and Visscher graphs and data of Kreutz for CO2 levels in the 1940s. In addition, there is no mention in the text provided in the above link of CO2 concentrations reaching 430 ppmv in the 1940s. In fact, their data substantiates the belief that CO2 levels rose from approximately 290 ppmv at the outset of the industrial revolution to current levels of approximately 375. Granted, Kurschner and Visscher graphs show a spike to 390 ppmv, but that controversy must still be worked out.

Excellent observation indeed. The stomata techique uses *"known"*(??) CO₂ levels of the 20th century to 'measure' the stomata sensitivity. This is based on the Keeling / Callendar graph and Siple Dome ice core. None of it accounts for the 1940ies spike.

So, what they did was substituting the assumed CO2 levels on the time scale, that made 1940 equal to some 307 ppmv. Now, if you look at all the calibrating graphs with the linear regressions, you'll see that at 307 ppmv not a lot is happening. Very few samples. An odd sample around that area shows indeed lower values. Transversing those samples to an imaginary 400-420ppmv point would still leave a reasonable regression with a lower stomata sensitivity, although one would not be proud of the r2 values.

I'd say that the 20th century values neither exclude nor substantiate the spike.

 

[Sinimod]

Excellent observation indeed. The stomata techique uses *"known"*(??) CO₂ levels of the 20th century to 'measure' the stomata sensitivity. This is based on the Keeling / Callendar graph and Siple Dome ice core. None of it accounts for the 1940ies spike.

So, what they did was substituting the assumed CO2 levels on the time scale, that made 1940 equal to some 307 ppmv. Now, if you look at all the calibrating graphs with the linear regressions, you'll see that at 307 ppmv not a lot is happening. Very few samples. An odd sample around that area shows indeed lower values. Transversing those samples to an imaginary 400-420ppmv point would still leave a reasonable regression with a lower stomata sensitivity, although one would not be proud of the r2 values.

I'd say that the 20th century values neither exclude nor substantiate the spike.

I am certainly no expert in stomatal methodology for estimating atmospheric CO2 concentrations. Nor do I profess to have an intimate understanding of Kreutz's methodolgy. But a discrepancy of over 100 ppmv CO2 concentration strains credibility. It appears to me that one must choose which methodology works here, and which doesn't. At this point, I place my bets on the Taylor ice core data from Antarctica. Calcium dust concentrations are extremely low in ice cores from Antarctica, and are considered to have virtually no effect on estimates of CO2 concentrations. Perhaps you could provide references on the effects of extremeophiles in ice and how their activities could compromise oxygen isotope estimates of paleotemperatures or atmospheric CO2 concentrations.

 

[Andre]

...Perhaps you could provide references on the effects of extremeophiles in ice and how their activities could compromise oxygen isotope estimates of paleotemperatures or atmospheric CO2 concentrations.

Wrong connection. extremophiles ruin CO₂ concentration proxies, not water isotopes. They do that when the ice sheets are too warm, which is the case with all high accumulation ice cores. The low accumulating ice cores seem cold enough (Vostok, EPICA Dome-C) but lack resolution.

The paleothermometers are severely biased by precipitation. You can only "measure" temperature when it snows. There are basically two problems.

1. When it snows, it's usually warmer than average:

http://www.phys.uu.nl/~helsen/PDF/thesis.pdf

2. Changes in seasonality of precipitation changes the annual ratio of light/cold winter snow and heavy/warm summer snow. Let me quote a small part of a submitted article:

It may be recalled, for instance, that the isotope spikes in the ice cores are thought to represent warm-cold transitions instead of dramatic precipitation changes. Fortunately, it had been recognized for a long time that these isotope changes could also be caused by precipitation changes depending on the seasonality[1]. This idea, however, has been rejected on the base of climate modeling[2], due to the absence of evidence of all these complications. More and more articles are now emerging, though, which report much earlier warming than the Greenland ice cores reveal[3], and more articles about the Younger Dryas appear to confirm the dry character much more than the cold character[4]. It could have been cold in many places, but not as cold as the ice cores suggest. Moreover, several studies report warm summers in that period.[5]


Digging further, it appears that we do indeed encounter a controversy about the nature of these isotope spikes. As it is becoming increasingly clear now that the Northern Hemisphere warming after the Last Glacial Maximum was much earlier (ca. 17 ka Cal BP) than the Bølling Allerød spikes (14.5 ka Cal BP) in the ice cores suggested, synchronous with the post-glacial warming of the Southern Hemisphere[6]. However, the same almost identical isotope spikes are recognized in several other sediment proxies over the Northern Hemisphere[7], hence indeed too late to register that warming. Consequently, those cannot be seen as the usual proxies for temperatures. So,it becomes apparent that some re-considerations of the conclusions are in order.


1. Steig E.J., P.M. Grootes, M Stuiver 1994. Seasonal Precipitation Timing and Ice Core Records, Science 16 December: 1885-1886

2. Jouzel, et al 1997, Validity of the Temperature Reconstruction from Water Isotopes in Ice Cores; Journal of Geophysical Research Vol 102, No C12 pp 26,471-26,487, November 30

3. Schaefer, J.M. et al 2006; Near-Synchronous Interhemispheric Termination of the Last Glacial Maximum in Mid-Latitudes Science 9 June 2006: Vol. 312. no. 5779, pp. 1510 – 1513

4. Clark, D.H, 2003, Complex Timing and Patterns of Glaciation in the American Cordillera during Termination 1, Poster presentation XVI INQUA Congress, Paper No. 88-4, July 30.

5. Björck, S., et al, 2002. Anomalously mild Younger Dryas summer conditions in southern Greenland. Geology May, v. 30; no. 5; pp. 427–430

6. Schaefer, J.M et al 2006; Near-Synchronous Interhemispheric Termination of the Last Glacial Maximum in Mid-Latitudes Science 9 June 2006: Vol. 312. no. 5779, pp. 1510 – 1513

7. Yu Z, Eicher U 2001 Three Amphi-Atlantic Century-Scale Cold Events during the Bølling-Allerød Warm Period, Geographie Physique et Quaternaire ISSN : 0705-7199 2001 Vol. 55 pg - 171-180