About carbon isotopes and oxygen use…
1. The different carbon isotopes in nature.
The carbon of CO2 is composed of different isotopes. Most is of the lighter type: 12C, which has 6 protons and 6 neutrons in its nucleus. About 1.1% is the heavier 13C which has 6 protons and 7 neutrons in the nucleus. There also is a tiny amount of 14C which has 6 protons and 8 neutrons in the nucleus. 14C is continuously formed in the upper stratosphere from the collisions of nitrogen with cosmic rays particles. This type of carbon (also formed by above-ground atomic bomb experiments in the 1950’s) is radio-active and can be used to determine the age of fossils up to about 60,000 years.
One can measure the 13C/12C ratio and compare it to a standard. The standard was some type of carbonate rock, called Pee Dee Belemnite (PDB). When the standard rock was exhausted, this was replaced by a zero definition in a Vienna conference, therefore the new standard is called the VPDB (Vienna PDB). Every carbon containing part of any subject can be measured for its 13C/12C ratio. The comparison with the standard is expressed as d13C in per thousand (the term mostly used is per mil):
(13C/12C)sampled – (13C/12C)standard
————————————————————— x 1.000
(13C/12C)standard
Where the standard is defined as 0.0112372 part of 13C to 1 part of total carbon. Thus positive values have more 13C, negative values have less 13C. Now, the interesting point is that vegetation growth in general uses by preference 12C, thus if you measure d13C in vegetation, you will see that it has quite low d13C values. As fossil fuels were formed from vegetation (or methanogenic bacteria, with similar preferences), these have low d13C values too. Most other carbon sources (oceans, carbonate rock wearing, volcanic degassing,…) have higher d13C values. For a nice introduction of the isotope cycle in nature, see the web page of Anton Uriarte Cantolla ( http://homepage.mac.com/uriarte/carbon13.html ).
This is an interesting feature, as we can determine whether changes of CO2 levels in the atmosphere (observed to be currently -8 per mil VPDB) were caused by vegetation decay or fossil fuel burning (both about -24 per mil) or by ocean degassing (0 to +4 per mil).
2. Trends in carbon isotope ratios, the 13C/12C ratio.
From different CO2 baseline stations, we not only have CO2 measurements, but also d13C measurements. Although only over a period of about 25 years, the trend is clear and indicates an extra source of low d13C in the atmosphere.
Recent trends in d13C from direct measurements of ambient air at different baseline stations.
Data from http://cdiac.ornl.gov/trends/co2/contents.htm
ALT=Alert; BAR=Barrow; LJO=La Jolla; MLO=Mauna Loa; CUM=Cape Kumukahi; CHR=Christmas Island; SAM=Samoa; KER=Kermadec Island; NZD=New Zealand (Baring Head); SPO=South Pole.
Again, we see a lag in the trends with altitude and NH/SH border transfer and less variability in the SH. Again, this points to a source in the NH. If that is from vegetation decay (more present in the NH than in the SH) and/or from fossil fuel burning (90% in the NH) is solved in the investigation of Battle ea. http://www.sciencemag.org/cgi/reprint/287/5462/2467.pdf
More up-to-date (Bender e.a.) and not behind a paywall:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
Where it is shown that there is less oxygen used than can be calculated from fossil fuel burning. Vegetation thus produces O2, by incorporating more CO2 than is formed by decaying vegetation (which uses oxygen). This means that more 12C is incorporated, and thus more 13C is left behind in the atmosphere. Vegetation is thus a source of 13C and is not the cause of decreasing d13C ratios.
And we have several other, older measurements of d13C in the atmosphere: ice cores and firn (not completely closed air bubbles in the snow/ice). These align smoothly with the recent air measurements. There is a similar line of measurements from coralline sponges and sediments in the upper oceans. Coralline sponges grow in shallow waters and their skeleton is built from CO2 in the upper ocean waters, without altering the 13C/12C ratio in seawater at the time of building. The combination of atmospheric/firn/ice and ocean measurements gives a nice history of d13C changes over the past 600 years:
Figure from http://www.agu.org/pubs/crossref/2002/2001GC000264.shtml gives a comparison of upper ocean water and atmospheric d13C changes.
What we can see, is that the d13C levels as well as in the atmosphere as in the upper oceans start to decrease from 1850 on, that is at the start of the industrial revolution. In the 400 years before, there is only a small variation, probably caused by the temperature drop in the Little Ice Age.
In comparison, over the whole Holocene, the variation of d13C was only 0.4 per mil:
http://www.nature.com/nature/journal/v461/n7263/full/nature08393.html
And the change in d13C from the coldest part of the last glacial to the warm Holocene Optimum was only 0.7 per mil, slightly over the recent d13C change:
http://epic.awi.de/Publications/Khl2004e.pdf
The decrease of d13C in the atmosphere cannot be caused by some extra outgassing from the oceans, as that would INcrease the d13C ratios of the atmosphere (even including the fractionation at the ocean-air border), while we see a DEcrease both in the oceans and the atmosphere. This effectively excludes the oceans as the main cause of the increase.
3. The 14C/12C ratio
14C is a carbon isotope that is produced in the atmosphere by the impact of cosmic rays. It is an unstable (radioactive) isotope and breaks down with a half-life time of less than 6,000 years. 14C is used for radiocarbon dating of not too old fossils (maximum 60,000 years). The amount of 14C in the atmosphere is variable (depends of the sun’s activity), but despite that, it allows for a reasonable good dating method. Until humans started to burn fossil fuels…
The amounts of 14C in the atmosphere and in vegetation is more or less in equilibrium (as is the case for 13C: a slight depletion, due to 12C preference of the biological reactions). But about half of it returns to the atmosphere within a year, by the decay of leaves. Other parts need more time, but a lot goes back into the atmosphere within a few decades. For the oceans, the lag between 14C going into the oceans (at the North Atlantic sink place of the great conveyor belt) is 500-1500 years, which gives a slight depletion of 14C, together with some very old carbonate going into solution which is completely 14C depleted. In pre-industrial times, there was an equilibrium between cosmogenic 14C production and oceanic depletion.
Fossil fuels at the moment of formation (either wood for coal or plankton for oil) incorporated some 14C, but as these are millions of years old, there is virtually no 14C anymore left. Just as is the case for 13C, the amount of CO2 released from fossil fuel burning dilutes the 14C content of the atmosphere. This caused problems for carbon dating from about 1890 on. Therefore a correction table is used to correct samples after 1890.
In the 1950’s another human intervention caused trouble for carbon dating: nuclear bomb testing induced a lot of radiation, which nearly doubled the atmospheric 14C content. Since then, the amount is fast decreasing, as the oceans replace it with “normal” 14C levels. The half life time of the excess 14C caused by this refresh rate is about 5 years.
This adds to the evidence that fossil fuel burning is the main cause of the increase of CO2 in the atmosphere…
T4. Trends in oxygen use.
To burn fossil fuels, you need oxygen. As for every type of fuel the ratio of oxygen use to fuel use is known, it is possible to calculate the total amount of oxygen which is used by fossil fuel burning. At the other hand, the real amount of oxygen which is used can be measured in the atmosphere. This is quite a challenging problem, as the change in atmospheric O2 from year to year is quite low, compared to the total amount of O2 (a few ppmv in over 200,000 ppmv). Moreover, as good as for CO2 as for oxygen, there is the seasonal to year-by-year influence of vegetation growth and decay. Only since the 1990’s, oxygen measurements with sufficient resolution are available. These revealed that there was less oxygen used than was calculated from fossil fuel use. This points to vegetation growth as source of extra O2, thus vegetation is a sink of CO2, at least since 1990.
This effectively excludes vegetation as the main cause of the recent increase.
The combination of O2 and d13C measurements allowed Battle e.a. to calculate how much CO2 was absorbed by vegetation and how much by the oceans (see the references above). The trends of O2 and CO2 in the period 1990-2000 can be combined in this nice diagram:
O2-CO2 trends 1990-2000, figure from the IPCC TAR
http://www.grida.no/climate/IPCC_tar/wg1/pdf/TAR-03.PDF
This doesn’t directly prove that all the CO2 increase in the atmosphere is from fossil fuel burning, but as both the oceans and vegetation are not the cause, and even show a net uptake, and other sources are much slower and/or smaller (rock weathering, volcanic outgassing,…), there is only one fast possible source: fossil fuel burning.
Engelbeen on why he thinks the CO2 increase is man made (part 3)
About carbon isotopes and oxygen use…
-
The different carbon isotopes in nature.
The carbon of CO2 is composed of different isotopes. Most is of the lighter type: 12C, which has 6 protons and 6 neutrons in its nucleus. About 1.1% is the heavier 13C which has 6 protons and 7 neutrons in the nucleus. There also is a tiny amount of 14C which has 6 protons and 8 neutrons in the nucleus. 14C is continuously formed in the upper stratosphere from the collisions of nitrogen with cosmic rays particles. This type of carbon (also formed by above-ground atomic bomb experiments in the 1950’s) is radio-active and can be used to determine the age of fossils up to about 60,000 years.
One can measure the 13C/12C ratio and compare it to a standard. The standard was some type of carbonate rock, called Pee Dee Belemnite (PDB). When the standard rock was exhausted, this was replaced by a zero definition in a Vienna conference, therefore the new standard is called the VPDB (Vienna PDB). Every carbon containing part of any subject can be measured for its 13C/12C ratio. The comparison with the standard is expressed as d13C in per thousand (the term mostly used is per mil):
(13C/12C)sampled – (13C/12C)standard
————————————————————— x 1.000
(13C/12C)standard
Where the standard is defined as 0.0112372 part of 13C to 1 part of total carbon. Thus positive values have more 13C, negative values have less 13C. Now, the interesting point is that vegetation growth in general uses by preference 12C, thus if you measure d13C in vegetation, you will see that it has quite low d13C values. As fossil fuels were formed from vegetation (or methanogenic bacteria, with similar preferences), these have low d13C values too. Most other carbon sources (oceans, carbonate rock wearing, volcanic degassing,…) have higher d13C values. For a nice introduction of the isotope cycle in nature, see the web page of Anton Uriarte Cantolla ( http://homepage.mac.com/uriarte/carbon13.html ).
This is an interesting feature, as we can determine whether changes of CO2 levels in the atmosphere (observed to be currently -8 per mil VPDB) were caused by vegetation decay or fossil fuel burning (both about -24 per mil) or by ocean degassing (0 to +4 per mil).
-
Trends in carbon isotope ratios, the 13C/12C ratio.
From different CO2 baseline stations, we not only have CO2 measurements, but also d13C measurements. Although only over a period of about 25 years, the trend is clear and indicates an extra source of low d13C in the atmosphere.
Recent trends in d13C from direct measurements of ambient air at different baseline stations.
Data from http://cdiac.ornl.gov/trends/co2/contents.htm
ALT=Alert; BAR=Barrow; LJO=La Jolla; MLO=Mauna Loa; CUM=Cape Kumukahi; CHR=Christmas Island; SAM=Samoa; KER=Kermadec Island; NZD=New Zealand (Baring Head); SPO=South Pole.
Again, we see a lag in the trends with altitude and NH/SH border transfer and less variability in the SH. Again, this points to a source in the NH. If that is from vegetation decay (more present in the NH than in the SH) and/or from fossil fuel burning (90% in the NH) is solved in the investigation of Battle ea. http://www.sciencemag.org/cgi/reprint/287/5462/2467.pdf
More up-to-date (Bender e.a.) and not behind a paywall:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
Where it is shown that there is less oxygen used than can be calculated from fossil fuel burning. Vegetation thus produces O2, by incorporating more CO2 than is formed by decaying vegetation (which uses oxygen). This means that more 12C is incorporated, and thus more 13C is left behind in the atmosphere. Vegetation is thus a source of 13C and is not the cause of decreasing d13C ratios.
And we have several other, older measurements of d13C in the atmosphere: ice cores and firn (not completely closed air bubbles in the snow/ice). These align smoothly with the recent air measurements. There is a similar line of measurements from coralline sponges and sediments in the upper oceans. Coralline sponges grow in shallow waters and their skeleton is built from CO2 in the upper ocean waters, without altering the 13C/12C ratio in seawater at the time of building. The combination of atmospheric/firn/ice and ocean measurements gives a nice history of d13C changes over the past 600 years:
Figure from http://www.agu.org/pubs/crossref/2002/2001GC000264.shtml gives a comparison of upper ocean water and atmospheric d13C changes.
What we can see, is that the d13C levels as well as in the atmosphere as in the upper oceans start to decrease from 1850 on, that is at the start of the industrial revolution. In the 400 years before, there is only a small variation, probably caused by the temperature drop in the Little Ice Age.
In comparison, over the whole Holocene, the variation of d13C was only 0.4 per mil:
http://www.nature.com/nature/journal/v461/n7263/full/nature08393.html
And the change in d13C from the coldest part of the last glacial to the warm Holocene Optimum was only 0.7 per mil, slightly over the recent d13C change:
http://epic.awi.de/Publications/Khl2004e.pdf
The decrease of d13C in the atmosphere cannot be caused by some extra outgassing from the oceans, as that would INcrease the d13C ratios of the atmosphere (even including the fractionation at the ocean-air border), while we see a DEcrease both in the oceans and the atmosphere. This effectively excludes the oceans as the main cause of the increase.
-
The 14C/12C ratio
14C is a carbon isotope that is produced in the atmosphere by the impact of cosmic rays. It is an unstable (radioactive) isotope and breaks down with a half-life time of less than 6,000 years. 14C is used for radiocarbon dating of not too old fossils (maximum 60,000 years). The amount of 14C in the atmosphere is variable (depends of the sun’s activity), but despite that, it allows for a reasonable good dating method. Until humans started to burn fossil fuels…
The amounts of 14C in the atmosphere and in vegetation is more or less in equilibrium (as is the case for 13C: a slight depletion, due to 12C preference of the biological reactions). But about half of it returns to the atmosphere within a year, by the decay of leaves. Other parts need more time, but a lot goes back into the atmosphere within a few decades. For the oceans, the lag between 14C going into the oceans (at the North Atlantic sink place of the great conveyor belt) is 500-1500 years, which gives a slight depletion of 14C, together with some very old carbonate going into solution which is completely 14C depleted. In pre-industrial times, there was an equilibrium between cosmogenic 14C production and oceanic depletion.
Fossil fuels at the moment of formation (either wood for coal or plankton for oil) incorporated some 14C, but as these are millions of years old, there is virtually no 14C anymore left. Just as is the case for 13C, the amount of CO2 released from fossil fuel burning dilutes the 14C content of the atmosphere. This caused problems for carbon dating from about 1890 on. Therefore a correction table is used to correct samples after 1890.
In the 1950’s another human intervention caused trouble for carbon dating: nuclear bomb testing induced a lot of radiation, which nearly doubled the atmospheric 14C content. Since then, the amount is fast decreasing, as the oceans replace it with “normal” 14C levels. The half life time of the excess 14C caused by this refresh rate is about 5 years.
This adds to the evidence that fossil fuel burning is the main cause of the increase of CO2 in the atmosphere…
4
-
Trends in oxygen use.
To burn fossil fuels, you need oxygen. As for every type of fuel the ratio of oxygen use to fuel use is known, it is possible to calculate the total amount of oxygen which is used by fossil fuel burning. At the other hand, the real amount of oxygen which is used can be measured in the atmosphere. This is quite a challenging problem, as the change in atmospheric O2 from year to year is quite low, compared to the total amount of O2 (a few ppmv in over 200,000 ppmv). Moreover, as good as for CO2 as for oxygen, there is the seasonal to year-by-year influence of vegetation growth and decay. Only since the 1990’s, oxygen measurements with sufficient resolution are available. These revealed that there was less oxygen used than was calculated from fossil fuel use. This points to vegetation growth as source of extra O2, thus vegetation is a sink of CO2, at least since 1990.
This effectively excludes vegetation as the main cause of the recent increase.
The combination of O2 and d13C measurements allowed Battle e.a. to calculate how much CO2 was absorbed by vegetation and how much by the oceans (see the references above). The trends of O2 and CO2 in the period 1990-2000 can be combined in this nice diagram:
O2-CO2 trends 1990-2000, figure from the IPCC TAR
http://www.grida.no/climate/IPCC_tar/wg1/pdf/TAR-03.PDF
This doesn’t directly prove that all the CO2 increase in the atmosphere is from fossil fuel burning, but as both the oceans and vegetation are not the cause, and even show a net uptake, and other sources are much slower and/or smaller (rock weathering, volcanic outgassing,…), there is only one fast possible source: fossil fuel burning.
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I am left wondering who it is that says human beings are not adding CO2 to the atmosphere. That is true while at the same time adding more water vapor.
CH4 + 2O2 => 2H2O + CO2
More molecules of water are added to atmosphere by at least 2:1 and reducing O2. The real story then is that we will not be able to breath at some point in the distant future because we have burned up all the oxygen.
Two thoughts come to mind. First is the fact that there are about 5 coal fires in the world that each emit as much CO2 as all the vehicles in the US annually. Second it the fact that in chemistry, there are no reactions that would distinguish between the isotopes of CO2 on a kenetic basis. There simply isn’t enough mass difference to impact their diffusion rates. In animals, molecules in cells are in dynamic equilibrium with the environment, so the animal reflects the isotopic ratio of the elements it is exposed to. C14 is incorporated essentially immediately into algae upon exposure to (14)CO2 (Lehninger, Biochemistry, 1970, p. 494. I haven’t heard about plant differentially absorbing (12)CO2 over (13)CO2 until this paper. Hard to believe based on chemical reaction rates. But if you really learned something in college, it is that you always need to learn more.
Anyone who has participated in a controlled burn of a patch of prairie grass understands that pre-industrial humans facilitated enormous CO2 emissions. Here in the central USA where prairie savannah dominated the landscape, entire states where thought to have been routinely burned off (every 1 to 3 years) by Native Americans.
I find this article quite convincing. The ocean outgassing explanation is fine on a millennial scale — e.g. Vostok’s time delays between temperature change and large CO2 changes — but since the bulk of the ocean’s CO2 content is in the deeper, colder ocean the time frame of ocean-driven changes would be on the order of overturning circulation, around a thousand years, plus or minus several centuries, with dribs and drabs from ENSO upwelling.
So yes, burning fossil fuels has caused the rise in CO2. Yes, it has warmed since the Little Ice Age. But, as the Idsos show quite convincingly at CO2Science.org, both of these phenomena are Good Things.
But whether there is a causal relationship between the CO2 and the temperature rise remains in serious question, since all the current evidence points to negative feedbacks so powerful that the actual radiative contribution of the CO2 increase over the last century may be anywhere from a third of a degree C to unmeasurably small.
Enneagram says:
September 16, 2010 at 5:29 am
That map seems instead a map of distribution of cattle.
—————————
Lots of swimming cattle in west Atlantic 😉
According to the IPCC 21 % (minimum) is manmade. With a preindustrial value of – 7 per mill, value of -26 per mill for fossil fuel, the decrease should be about – 11 per mill and not values araound – 8 per mill. Therefore this signature can’t be anthropogenic.
If the recent well established greening of the planet is factored in, how much CO2 would be released as it decays? I am inclined to believe that the greening of the planet is likely a cyclical phenomenon such that it will hit a peak and then diminish, regardless of what caused the peak (better irrigation, wetter warmer climate, etc). This means that towards the downside slope of the greening peak, decaying vegetation will emit quite a bit of CO2 as opposed to using it up, and will emit more and more as greater amounts decay.
correction: 21 % of CO2 in the atmosphere
I have not been able to find an explanation of the following circumstances, and wonder whwther your investigations can offer anything:
> Looking at Vostok CO2 data in the periods : Present to
> 10,000 years ago, 130,000 years ago to 140,000 years ago, 230,000 years
> ago to 240,000 years ago, 315,000 years ago to 325,000 years ago
> (which I take to be equivalent periods in the last four climate
> cycles) I note that in the current cycle atmospheric CO2
> concentrations have been on a rising trend whilst temperatures were on
> a generally falling trend, whilst in the earlier periods both CO2 and
> temperatures were on a falling trend. Is there an accepted theory as
> to why this should be so? In view of low human populations 10,000
> years ago, it seems unlikely that anthropogenic factors can have
> influenced the change in behaviour?
An excellent paper.
Makes a strong case that human activity, whether from deforestation/agriculture or fossil fuel burning, has had a substantial impact on the isotopic composition of atmospheric CO2.
The connection to AGW from this is very shaky at best, but fortunately the author did not even try to raise that claim.
His paper shows the scale of the human impact to be eye opening and does strongly indicate a much more serious effort to restore and protect the global biosphere, on whose health we all depend.
just sent an email to the UK Department od Energy and Climate Change
——————————————-
Ref: Is the DECC Global Warming Anomaly graph incorrect? An updated base line should be used.
In the graph below, published on the DECC website.
http://www.decc.gov.uk/assets/decc/statistics/climate_change/1_20100319151831_e_@ur momisugly@_surfacetemperaturesummary.pdf
In this graph the temperature anomalies are calculated fom the 1961-1990 average. (the base line)
By climate convention (and other data sets are now doing this) this base line is a moving one..
This graph should now calculate this graph, from a 1971-2000 base line..
Unless, this graph is brought uptodate and inline with climate science convention.
There will remain a suspicion, that the old baseline is being used, to show BIGGER anomalies, as evidence of man made global warming..
Or is it the case the anomalies are now smaller, if the correct base line is used?
If you could send me a recalculated graph with the correct baseline, I would be very apreciative,
(ie you will use the exact methods used to creat the graph, less I make any errors if I attempt it myself)
so that I can be reassured that this suspicion is not the case.
However the official DECC website should do this as well.
-end email———
Actually, if you actually look at the graphs, both uk and global anomalies are on a bit of a downslope anyway, since, ~ 1998..
A few more years of that and the will HAVE to start to explain a cooling trend…
Watch that graph
Yes , it all aligns so smoothly. You have not even convinced me the so called carbon dating back to 60,000 years is accurate, and dont get me wrong Ive read the theory. You do spin your hypothesis well though. I find much of this evidence is based on unproven or even unprovable assumptions and I wonder what you are up to.
Who cares? The argument is about whether increases in atmospheric CO2, beyond its current saturated levels, can cause CAGW – its that for which we await the proof.
Change my last comment from “PDB for organic” to PDB for inorganic.[i think everybody did . . b.mod]
Ants produce a lot of CO2.
This is probably a dumb question, so please forgive my ignorance. It is that ignorance I seek to reduce.
What we are discussing here is only the surplus or “excess” of a specific CO2 correct? And this excess CO2 is solely of the kind produced by fossil fuel combustion, right? Are we able to discern the difference between carbon from a forest fire as opposed to a fleet of oil tankers? Or carbon produced from an eruption opposed to oil sands production? Also, would wildfire suppression affect anything here? Indigenous lore has it that there used to be fires the size of California or larger that burned for months or years until the area was “settled” and fire suppression practiced.
I just want to separate the “apples” from the “oranges”.
Nice work. Hope to read what you think of UHI soon too. Seems to me concrete and steel and asphalt have a lot more to do with “man-made global warming” than CO2 AND there’s a lot of CO2 introduced into the atmosphere because of these three items. Looks like we’re slowly getting around to talking about the real problem; the BIG problem -UHI. Eventually, you can boil everything down to basics.
Among the many flaws in the essay, the assumption that anthropogenic sources are the only possible explanation for increased d13Carb increases is among the fatal flaws to the argument. It is well known among geologists that the bloom of calcerous marine marine plankton have been responsible for substantially positive excursions of d13C whenever nutrient levels and a warming environment have encouraged their growth and emissions.
Hey Englebeen, where are the computations that show how much less CO2 the oceans release due to man’s CO2 release. You and the rest never talk about the partial pressure of gasses and how our raising it suppresses natural release.
The CO2 level would have gone up anyway!!! You need to show us that it would not have been as high without man’s CO2 and you are not doing that!!!!
No, because rising sea levels during the inter-glacial and increased marine nutrients from all causes increase planktonic bloom and emissions of d13C.
Actually, as I understand it, isotopic carbon is preferentially sequestered with c13, mostly due to the reaction response rate, greater takeup energy requiring increased energy for release. How much of the ratio of such, at that point, would end up concentrated in lifeforms, thus preferentially ‘lightening’ the carbon in the cycle that is still ‘free’?
I fear one cannot have things both ways. It is either preferentially held within biology, or it is not. It requires increased time for the photosynthetic reaction to occur within the plant utilizing carbon 13 heavy co2, as well as increased activation energy for breaking the bond once formed.
A biological system may tend to release the energy that can be easily released preferentially. (hypothesis, testable). This would tend to sequester heavier carbon preferentially on death of the organism (hypothesis, testable). If so, would there not potentially be an experiment by which this could be determined, I.E. a closed system monitored for carbon 13 versus carbon 12 ratios in the atmosphere, checking for enrichment or depletion in-atmospheric carbon? Given the nature of the oxygen cycle, it would likely be effective to test it using photosynthetic algae.
If, indeed, a large percentage of the carbon dioxide is immediately taken up, there should be a change over time in the ratio of carbon (13) dioxide to carbon (12) dioxide.
Should the ratio remain stable, the experiment is falsified. If it is altered, the observation of ratios from coal and fossil fuels becomes meaningless in the debate, as it would be very difficult to maintain such a ratio if there is a preferential alteration.
It would appear C4 fixation of carbon is even more preferential than c3, and is a biologically ‘recent’ adaptation.
Anyone feel up to an experiment?
Dave Dardinger, what is a ‘fossil fuel denier’? And you obviously don’t realise that many of us who hang out at Anthony’s like to kinda sneak up on a discussion while we make random points and ask random questions that occur to us from the posting.
If you know anything about how people learn, typical male (which includes many females) learning behaviour is not linear but zaps about all over the topic (and often around, but not on it) and teases out all sorts of nuggets of information that are pushed and pulled as far as they will go until the subject is quite well explored and understood. The classic male learning style is about as orderly as a haystack built in a high wind, while classic female learning behaviour (and that includes many males) is linear, goal focussed and once the learner can pass the test or do the assignment at the end of the course the learning is very largely filed as ‘no longer neccessary on voyage’ and eventually drops from the memory completely. Male learners rarely forget any random fact that once excited their curiosity.
I’m here to learn, to contribute stuff where it seems appropriate and to enjoy hanging out with interesting people. Why are you here?
Food for thought.
“oil does not come exclusively, or even partly, from dinosaurs but is formed below the Earth’s 25-mile deep crust”
http://energy.probeinternational.org/fossil-fuels/endless-oil
I see someone appears to be conducting an advertising campaign on the Fox News Channel to announce their ‘great plan’ to save the environment with an extensive power plant carbon dioxide extraction and sequestration process. Of course, the rate payers will realize it is their civic duty to fund this procedure.
Isn’t this trying to prove that the majority of increased co2 is from man, not that man is the cause of the increase? Clearly if man is producing 4molecules per 1000 and the atmospere is increasing by 2 per 1000 there is something else going on there. In a stable system with feedbacks stating that most of the co2 in the atmospere is from man burning fossil fuels does not prove that if man had not burnt the fossil fuels the equilibrium would not have been made another way. i.e. if there is a feed back mechanism equalising the concentrations of co2 between the atmosphere and the ocean – or plants and atmosphere the presence of man made co2 restricts output from another source.
That is not to say the concentration has not been increased by man, but in effect you would have to prove first that concentrations of co2 in the atmosphere would be different if man had not burnt the fuels. As soon as you are involved with feedbacks – which clearly you are because the concentration increase does not increase the amount produced by man – showing the cause of the co2 in the atmosphere does not prove that if man had not burnt the fuel the concentration would have been less.
Put in simpler terms, if we had not burnt the carbon more co2 may have been gassed from the oceans to compensate, because the current temperature requires more co2 in the atmosphere.