Correlation of Net CO2 emissions with climate properties shows that the growth in CO2 may be natural
Story submitted by WUWT reader Steve Brown
The narrative of the catastrophic anthropogenic global warming has been challenged at many levels but this presentation by Professor Murry Salby, Chair of Climate at Macquarie University rips up the very foundations of the story.
The talk (in the video below) was given at the Sydney Institute 2nd Aug 2011
He elegantly shows that there is a solid correlation between natural climate factors (global temperature and soil moisture content) and the net gain (or loss) in global atmospheric content when the latter is averaged over a two year period. The hanging question remains, if natural factors drive more than 90% of the growth in CO2 how significant is the contribution of human generated emissions. The answer is simple… not very.
The talk has been covered in the past on Judith Curry’s blog, and an abstract of the talk is here . But this is the first time I have encountered a video of the talk or been able to see the slides which he referenced.
Fascinating.
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And, should have said: “I AM saying that the mass balance argument, the one which includes the portion of mass going into the expanded sinks, is inconclusive in regard to the proportions of natural and anthropogenic fluxes which have contributed to that rise.”
No one should be permitted to comment on the topic of anthropogenic climate change until they have viewed Dr. Salby’s talk.
This is eye-opening stuff. No wonder Judith Curry’s response was, “Wow.”
REPLY – Regardless of how Wow it is or is not, we really mustn’t be saying that no one should be “permitted” to comment on pretty much anything. That sword has two edges. ~ Evan
No Smokey,
“At current and projected levels, CO2 is harmless, and beneficial to the biosphere.”
” Simply identify global damage or harm due to the rise in CO2, and the hypothesis is falsified. Conversely, no harm = harmless.”
it is not that simple, because your statement contains undefined value judgements in the terms “beneficial” and “global damage or harm”, which makes it non-scientific. You would have to define those, and that would be difficult unless something occurred to threaten all life on the planet, which is quite ridiculously unlikely.
At the moment people cannot even agree on the evidence let alone the consequences. For example your statement
“It is a proven fact that oceans outgas CO2 as they warm”
is not at all proven. This is why I prefer to remain agnostic on this at the moment.
jimmi_the_dalek,
You’re squirming around like a fish on a hook. First you said that we don’t have another planet. Now you’re trying to split hairs over global harm. “Harm” means anything detrimental that is specifically caused by the rise in CO2. Get out a dictionary and look up “harm”. You will find that ‘harm’ is not “undefined”, and it is not a “value judgement”. It has a specific definition.
You will also note that the entire global warming debate is over CO2-induced catastrophic AGW. But no one demands to have ‘catastrophic’ defined, because if there is a catastrophe everyone will know it. The same thing is true of global harm: if rising CO2 caused global harm, you can be certain that the entire alarmist contingent would be jumping up and down and pointing to it. The reason that they don’t is simple: there is no harm caused by rising CO2. Therefore, CO2 is harmless. QED
As for ‘beneficial’, only blinkered true believers falsely claim that CO2 is not beneficial. It is necessary for all life on earth [with the tiny exception of some anaerobic bacteria]. Satellite data shows that the earth is greening in lock step with rising CO2. And you could not live without CO2. Now tell us again that CO2 is not beneficial.
The planet is starved of CO2. More is better. I can give you plenty of examples. But 5 should be sufficient to make my point:
click1
click2
click3
click4
click5
Finally, you replied to my asserting that it is a proven fact that oceans outgas CO2 as they warm, by saying that it “…is not at all proven”. Of course it is. You really need to get up to speed on the subject. It is a proven fact that warming oceans outgas CO2. That is where most of the current rise comes from.
But that is beside the point. The fact is that you cannot falsify my hypothesis, so you tapdance around it with statements that are easily deconstructed. It is a testable, falsifiable hypothesis, and all you need to falsify it is to show global harm due specifically to the rise in CO2. But since there is no such harm, the hypothesis remains standing.
Smokey,
Your graph shows the solubility of CO2 AT CONSTANT PRESSURE. Now go and look up Henry’s
Law and the effect of increasing the partial pressure before you go around telling people to ‘get up to speed’
jimmi,
So what? The table proves that the ocean outgases CO2 depending on temperature, which you disputed. Go open a beer. Let it warm. Observe. Then come back and try to explain that warming does not cause CO2 to outgas. Again, you need to get up to speed on the subject.
And naturally you ignored the easy deconstruction of your other arguments. I don’t blame you. I provided a testable, falsifiable hypothesis. Making unrelated arguments doesn’t make the hypothesis any less falsifiable.
Smokey
You really don’t know what you are talking about – warm beer indeed – when you open a bottle of beer, or anything with dissolved CO2, you have changed the pressure. Now, I see you have not checked Henry’s Law, so you have lost that argument. The pressure change easily dominates the temperature for the ranges of partial pressures and temperatures being discussed.
As for the rest, well you came nowhere close – dictionary definition of harm ….
Look, I am not a believer in CAGW, more a luke warmer at most, so I consider that at worst all that will happen is some economic reorganisation (and not even that is definite). So here is a (totally hypothetical) scenario. Supposing rainfall patterns change so that growing corn and wheat in the MIdWest USA becomes uneconomic. Would that be harm? But what if the same change in rainfall patterns enabled wheat to be grown in the Sahara? That is the sort of change that may (completely hypothetically) occur. So can you tell me whether that is net harm or net benefit? I doubt if anyone can, which is why your statement is full of undefined value judgements.
jimmi,
It appears you need hand-holding. OK:
Open the beer, then put it back in the refrigerator for a day. Then take it out and let it assume room temperature. What happens? CO2 outgases as the beer warms, with no change in pressure.
…and my hypothesis remains un-falsified.
And: “Supposing rainfall patterns change so that growing corn and wheat in the MIdWest USA becomes uneconomic. Would that be harm?”
No. The criteria is global harm. Regions constantly fluctuate.
And:
“…your statement is full of undefined value judgements.”
Only to you, because you seem unable to use a dictionary to ‘define’ terms. But don’t feel bad, no one else has been able to falsify the hypothesis either. If it remains standing, eventually it will be elevated to the status of a theory. That is how the scientific method works.
“Open the beer, then put it back in the refrigerator for a day. Then take it out and let it assume room temperature. What happens? CO2 outgases as the beer warms, with no change in pressure.”
That’s not the experiment you need to do. You need to open it in an atmosphere with 280ppm CO2, let it equilibriate, then put it in an atmosphere with 400 ppm CO2, and see which way the CO2 goes. If you like you can raise the temperature by 0.8C at the same time and see which effect dominates.
I may be wrong, because Salby doesn’t give numbers or formulas, but he appears to be saying that net emissions depend largely on temperature and to a lesser extent on soil moisture. Obviously net emissions give us the rate at which atmospheric CO2 is rising. So it is the rate of increase, not the level, of CO2 that varies with temperature.
Most users of this site presumably agree that the mediaeval warm period from 900 AD to 1300 AD was at least as warm as the last quarter of the 20th century. Assuming no enormous difference in soil moisture this means that net emissions during those four centuries should have run, on average, at at least the same rate as for the period 1975 to 2000.
In the last quarter of the 20th century CO2 concentration increased by about 35 ppm. Multiplying this by 16 gives a total increase of 560 ppm during the four centuries of the MWP.
Assuming that Cal is right about the limit for photosynthesis being 150 ppm we can assume that CO2 concentrations at the beginning of the MWP were at least at that level. This yields a minimum level of 710 ppm (a little less than twice current levels) at the end of the MWP. Even allowing for some diffusion it should be possible to detect an increase of this magnitude in ice cores and other proxies. In this way one could firmly establish that the MWP really was warmer than today and that Salby’s theory is correct.
jimmi,
It’s geting late here, and I’m embarassed to be debating with an unarmed opponent. So you get the last word; I’m done posting for the night.
You seem to believe that atmospheric CO2 controls the temperature, rather than accepting the obvious fact that ocean temperatures control atmospheric CO2. Fine, if that is your belief system, there is nothing I can do to overcome it or educate you. True belief is insurmountable, as it is based on emotion, not science. [But for others reading this, the planet’s oceans do control atmospheric CO2, not vice-versa.]
Good night, jimmi. You have consistently failed to falsify my hypothesis with a single example of global harm due to the rise in [harmless, beneficial] CO2, but your consolation prize is that you get to have the last word.
Smokey
“Fine, if that is your belief system, there is nothing I can do to overcome it or educate you. True belief is insurmountable, as it is based on emotion, not science. ”
You do realise you are describing yourself there?
There are competing effects. The partial pressure of CO2 in the atmosphere has increased by roughly 40% in the last couple of centuries. This means basically that the atmospheric CO2 is pushing against the ocean 40% harder and is this 40% more likely to be absorbed (Henry’s Law – absorption is proportional to pressure). The temperature of the ocean has risen by less than a degree in that time. The solubility has therefore decreased by about 3%. i.e. CO2 is 3% less likely to stay in solution. Now which is greater 40% or 3%? To complicate things even more, pushing the gaseous CO2 in the atmosphere into the ocean is a fairly simple process, getting it out again is more complicated as most of the oceanic CO2 is not little bubbles , it is held as bicarbonates (HCO3) or carbonic acid (H2CO3). You still think it is obvious that the net direction is outwards?
Not very sceptical of you (ie you are holding a viewpoint without checking it).
Although I support the ocean outgassing hypothesis we do still need to resolve the discrepancy between proxy records (especially ice cores) and the sheer size of the apparent CO2 increase in proportionate terms observed during the 20th century.
As scepticalwombat points out the implication of that rate of rise suggests very large proportionate changes in atmospheric CO2 between MWP and LIA and LIA to date.
Likely there is a combination of factors involved such as coarse proxy records unable to reproduce such a high level of natural variability plus CO2 not necessarily being well mixed at all levels, all locations and at all times plus high variability in the efficiency of other local and regional non oceanic sinks and sources but that is an isue that must be resolved if the ocean outgassing process is to be pinned down as the primary global variable.
“oceanic CO2 is not little bubbles , it is held as bicarbonates (HCO3) or carbonic acid (H2CO3). You still think it is obvious that the net direction is outwards?”
I’d like to see a better analysis as to how variable the oceans can be in their rates of CO2 absorption or emission from place to place and from time to time.
I suspect that biologcal processes within the oceans could be a significant factor in changing the balance of CO2 exchanges with the air over time thus rendering the influence of Henry’s Law less significant than might first be thought.
jimmi_the_dalek says: April 22, 2012 at 10:14 pm You realize 40% of almost zero is ,well, almost zero.
Here’s my response, taken from chapter C of my book, THE A-Z OF GLOBAL WARMING, which i’m currently updating. CO2 is present in the Earth’s atmosphere at a low concentration, around 0.038% by volume, and is one of many gases that make up Earth’s atmosphere. CO2 is measured in parts per million by volume of air (PPMV). Atmospheric carbon dioxide derives from many natural sources including volcanic eruptions, the combustion of organic matter, the respiration of living aerobic organisms, and unfortunately from manmade (anthropogenic) sources, which we all know from the news is being linked to global warming and climate change.
Since the industrial revolution particularly the mid nineteenth century, the burning of fossil fuels for energy to provide electricity, power factories, homes and for all our transport needs has released massive amounts of carbon dioxide (CO2) into the atmosphere. Not only the burning of fossil fuels, but changes in the use of the land for agriculture and deforestation has further added to global manmade CO2 levels. According to the World Wildlife fund some 29 gigatons which is 29 billion metric tons of CO2 was added to the atmosphere in 2004 alone from burning coal, oil and gas.
If we go back 250 years or so, to pre- industrial times, usually taken to be around 1750, CO2 levels in the atmosphere stood at around 280 parts per million by volume (ppmv). However levels of the gas have been increasing steadily ever since.
HOW DO WE KNOW THIS?
Well, pioneering scientist Charles Keeling (1928-2005) started taking atmospheric CO2 measurements in 1958 from Mauna Loa volcano in Hawaii. Those measurements have been recorded and are now known as The Keeling Curve. Charles Keeling was the professor of oceanography at the Scripps Institute of Oceanography (SIO) which is in San Diego, USA, and he followed the work of another eminent scientist and director of the SIO, Roger Revelle. Dr Revelle was instrumental in creating the Geophysical Year in 1958 and SIO’s first programme looking at atmospheric CO2 back in 1956.
Monthly CO2 measurements were collected from a height of 3397 metres (11,140 feet) at the Mauna Loa Observatory situated on the slopes of Earth’s largest volcano, Mauna Loa in Hawaii which was chosen for its remoteness to populations and vegetation so as not to skewer the readings.
Measurements have been taken over a 50 year period between 1958 and present, which show an increase in CO2 levels of 70 ppmv from around 315 ppmv to around their current level of 385 ppmv. The effects of CO2 in the atmosphere can even be measured on a cyclical basis, and this can be seen in the saw toothed keeling graph. Because there is greater land area, and thus far more plant life in the Northern Hemisphere compared to the Southern Hemisphere, there is an annual fluctuation of about 5 ppmv peaking in May and reaching a minimum in October. This corresponds to the Northern Hemisphere growing season. The amount of CO2 in the atmosphere drops towards spring when uptake by the plants and trees by photosynthesis is greatest. The opposite occurs in winter when the plants die off and CO2 levels rise again.
Continuous readings in this way have only been taken since 1958, however scientists have discovered that prior to the industrial era, circa 1750, CO2 levels stood at around 280 ppmv and this data has been revealed from air trapped in ice core records, taken from both the Antarctic and Arctic. Perhaps most startling is the fact that CO2 levels are now around 85 ppmv higher than at any time during the last 650,000 years. Records from ice core records go back that far and have shown atmospheric CO2 levels to range from 180-300 ppmv during that period. The level of CO2 in our atmosphere now stands at 385 ppmv, and is increasing steadily.
The Keeling curve has become one of the most recognisable images in modern science as it shows with no uncertainty the effects of humankind’s fossil fuel pollution of Earth’s atmosphere.
CO2 levels have increased by 37% since pre-industrial times and have been increasing by an average of almost 1.4 ppmv a year since measurements began in 1958, although some months the figure has been higher, sometimes lower. In the last ten years however, the average increase appears to be around 1.9 ppmv each year, which indicates the rate of increase is increasing.
Whilst CO2 is a natural greenhouse gas, and important in natural concentrations to maintain Earth’s climate, anthropogenic CO2 is now pushing up Earth’s temperature. Earth’s natural sinks, like the Amazon rainforest and the oceans struggle to absorb the additional CO2 now being added to the atmosphere from the burning of fossil fuels. It is a know scientific fact that higher levels of greenhouse gases, of which CO2 is a component cause a warming of Earth’s atmosphere. If CO2 is not kept in check and continues to rise at current levels it will eventually cause Earth’s temperature to increase to levels which maybe critical to life on Earth.
Earth’s temperature has already increased by 0.74 degrees Celsius (1.33 Fahrenheit ) over the last 100 years……The USA just experienced the warmest March 2012 since records began, and 2010 tied with 2005 for the warmest year globally on record…
Okay guys I’ve got it. I finally understand what Bart was trying to say. Here is the explanation.
By the mass balance principle, although the net change in Nature (ocean+biosphere) carbon content can be calculated from the Industry content reduction and the Atmospheric content increase, that calculated number by itself says nothing about how this change is divided between the ocean and the biosphere, and therefore says nothing about how much larger the ocean flux is than the anthropogenic flux.
As we divide each bucket into smaller buckets, the sub-buckets can be any amount which adds up to their parent bucket.
In the first step the bucket is the entire world and the sum must equal zero.
In the second step the World bucket is divided into Anthropogenic, Atmosphere, and Nature, and the sum must equal zero. We plug in 2004/2005 data and we calculate that the change in the Nature bucket must have been +4 Gt/y, i.e.- Nature was a net sink of carbon.
In the third step we divide the Nature bucket into Ocean and Biosphere buckets, and their deltas must sum to +4 Gt/y. Bart’s point is that ANY pair of numbers which sum to +4 satisfies this equation.
dikranmarsupial would say the ocean change is positive, perhaps between 1 and 3 Gt/y, that the ocean is a net carbon sink, and the Biosphere change would therefore be between +3 and +1 to balance.
Bart is likely to say that the Ocean annual bucket change is -8 Gt/y (or more) so that the Ocean is a net source of carbon and also a larger contributor than Industry, although this necessarily creates the requirement that the Biosphere must be sinking +12 Gt/y for the result to balance to +4.
Evidence is the discriminator between competing hypotheses. Even knowing the ocean flux is 20 times larger than anthropogenic flux does not tell us the answer. We need to introduce new sources of evidence.
There is no evidence that the Biosphere is sinking 12Gt/y, if there is please show it, and in that case the widely accepted figures of around 2.4Gt/y must be wrong by a factor of 5x.
There is however the observation of global ocean pH reduction over previous decades, which at the very least implies that the Ocean change is positive, not negative.
Thus it is impossible for the ocean to be a net source of carbon based on 2004/2005 data and the ocean pH trend.
We must recognise there are two competing forces operating on the ocean’s carbon content. There is the diffusion / Le Chatelier Principle force which tries to dissolve carbon into the ocean out of the atmosphere due to carbon being artificially injected into it. Oppositely, there is Henry’s Law which is trying to outgas CO2 from the ocean due to the slight late 20th century rise in temperature. Depending on how similar these forces are, they may alternately overpower each other, or one may dominate the whole time.
In 1998 the annual increase in atmospheric C was more than industrial emission, thus it seems likely that the very warm El Nino that year drove Henry’s Law to overcome Le Chatelier’s Principle and make Nature a net source of carbon into the atmosphere. That is the only year in the last 30 years that this happened. The rest of the time both the Biosphere and the Ocean are a net sink of carbon. This implies industry is the main contributor to recent CO2 rise.
I have updated my diagram from earlier with links to evidence, here it is: http://imgur.com/iNmSc
Perhaps that can serve as basis for discussion, but personally I think this is the final answer to the CO2 “whodunnit” question.
Skepticalwombat said:
“Assuming that Cal is right about the limit for photosynthesis being 150 ppm we can assume that CO2 concentrations at the beginning of the MWP were at least at that level. This yields a minimum level of 710 ppm (a little less than twice current levels) at the end of the MWP. Even allowing for some diffusion it should be possible to detect an increase of this magnitude in ice cores and other proxies. In this way one could firmly establish that the MWP really was warmer than today and that Salby’s theory is correct.”
Surely more important for Salby’s theory that a 0.8 C rise in temperature causes a 120 ppm increase in atmospheric carbon dioxide is what you get working backwards to the last glacial maximum, which was 4-6 C colder than today. With CO2 at 393 ppm today that gives a negative CO2 concentration at the LGM.
One can dismiss the ice cores as much as one likes, but if there was no carbon dioxide in the atmosphere at the LGM, how did life as we know it survive?
Steve Keohane,
jimmi is so far from being up to speed on the subject that the only way I can think of for him to get educated is to begin reading the WUWT archives, keyord: CO2. He is typical of the general public that believes “carbon” is a problem. But as we see, that perception is changing.
jimmi is once again changing the subject instead of trying to falsify my testable hypothesis, which I have been challenging the alarmist crowd [and everyone else, including me] to try and falsify. I would be perfectly happy to have it falsified, because that would add another piece to the puzzle. Scientific truth is what is important, nothing else. But so far no one, including me, has been able to identify any verifiable global harm due to the ≈40% rise in that very tiny trace gas — which as you pointed out, is still a very tiny trace gas.
CO2 has been up to twenty times higher in the geologic past, causing no ill effects [ie: no global harm]. During those times the biosphere teemed with life. And a warmer planet is also a healthier planet, despite the crazed, wild-eyed alarmist arm-waving. Another 2ºC would be just fine. The planet has been warmer than that many times during the Holocene. It is cold that kills.
It’s fun to smoke out chameleons like jimmi, who probably believe that their posts fool anyone. They come here from their thinly trafficked alarmist blogs [which are steadily going out of business] and try to peddle thier nonsene to people here who know better: CO2 is not a problem. More is better. CO2 is harmless and beneficial. The entire “carbon” scare is fabricated nonsense, promoted by a relatively small clique of climate charlatans riding the taxpayer-funded gravy train.
In the end, it all comes down to one central fact: there is no verifiable evidence that the rise in CO2 has caused any harm. None. That is why jimmi keeps trying to change the subject. If he admitted the plain truth — that CO2 is harmless and beneficial — he would have to find a new religious cult to join.
scepticalwombat says:
April 22, 2012 at 8:50 pm
I may be wrong, because Salby doesn’t give numbers or formulas, but he appears to be saying that net emissions depend largely on temperature and to a lesser extent on soil moisture. Obviously net emissions give us the rate at which atmospheric CO2 is rising. So it is the rate of increase, not the level, of CO2 that varies with temperature.
Most users of this site presumably agree that the mediaeval warm period from 900 AD to 1300 AD was at least as warm as the last quarter of the 20th century. Assuming no enormous difference in soil moisture this means that net emissions during those four centuries should have run, on average, at at least the same rate as for the period 1975 to 2000.
In the last quarter of the 20th century CO2 concentration increased by about 35 ppm. Multiplying this by 16 gives a total increase of 560 ppm during the four centuries of the MWP.
Assuming that Cal is right about the limit for photosynthesis being 150 ppm we can assume that CO2 concentrations at the beginning of the MWP were at least at that level. This yields a minimum level of 710 ppm (a little less than twice current levels) at the end of the MWP. Even allowing for some diffusion it should be possible to detect an increase of this magnitude in ice cores and other proxies. In this way one could firmly establish that the MWP really was warmer than today and that Salby’s theory is correct.
====================
I don’t understand why you’re using the increase of a late quarter century to get to your 710 ppm, that carbon dioxide has risen by a certain amount in a particular time frame doesn’t mean that it would keep rising by that amount in every warming period, I think an extrapolation too far. Assuming the MWP was hotter or as hot as now and assuming the plant life was as abundant or more so, the increase should be to the whole length of the period from the end of the LIA to present, which may or may not be the end of our particular warming period, compared with beginning to end of MWP. We’re still uncovering vegetation in existence in the MWP as ice continues to melt which is only now coming to light since the ice of the LIA destroyed it.
Anyway, that still leaves the problem of whose measurements to use. Various plant stomata studies show levels of carbon dioxide that are similar to the chemical analyses done, and here http://debunkhouse.wordpress.com/2010/03/28/co2-ice-cores-vs-plant-stomata/ shows by stomata analysis there there is a distinct lag behind temperature before CO2 rises.
Lots of stuff has to be considered when analysing plant stomata – type of plant, where, etc. – but does make a good proxy for CO2 levels: http://www.concord.org/~btinker/gaiamatters/investigations/stomata.html
“It turns out that in many species, high-altitude ecotypes have a higher stomatal density than their lowland ecotypes. This can correlate with many differences between the two habitats, including temperature, exposure, water conditions, and variations in atmospheric composition. Some experimentation by F. I. Woodward and F. A. Bazzaz has demonstrated that the relevant variable is CO2 partial pressure – the proportion of CO2 in the atmosphere. In their experiments, the clearest result was that a reduction of CO2 led to an increase in stomatal density. Further work suggests that CO2 and stomatal density are inversely correlated — more CO2, fewer stomata.”
(The more CO2 available the less the plant has to struggle to get dinner.)
But there’s also that the ice core records could be much too low, without going into all the arguments here, it could simply be because there is no flora producing it in abundance, there’s only mainly from volcanic activity or brought in by wind systems. Here in the first link stomata levels show higher CO2 pre-industrial than ice core, as high as today, and in the second, that ice core also records higher CO2 at the turn of the last century than measurements at Mauna Loa in the 60’s.
http://tucsoncitizen.com/wryheat/tag/carbon-dioxide/
“Another proxy, plant stomata can be used to estimate pre-industrial carbon dioxide content. Stomata are the microscopic pores in leaves and stems of plants that are used for gas exchange. The density of stomata varies inversely with carbon dioxide concentration. These stomata can be empirically calibrated by comparing plant stomata density to known carbon dioxide concentrations. The stomata of fossil plants can be used to estimate past carbon dioxide concentrations. Estimates of carbon dioxide from stomata show much higher and more variable values compared to ice core estimates. The stomata proxy shows that pre-industrial carbon dioxide levels were similar to those today: 360- to 390ppmv.”
http://americasuncommonsense.com/blog/category/science-engineering/climate-change/5-ice-cores/
“In some cases, the trapped “atmosphere” in the ice sheets may not be part of a closed system. To be a closed system for carbon dioxide or methane, no gas components can escape or be added during the burial process; liquid water cannot have interacted with the gases; none of the trapped gas components can combine, separate, diffuse, or solidify; and all components must stay in the same proportions as pressure increases with time due to added ice above. The observational science of ice has demonstrated that for some cores all these conditions do not hold. Further, the process of core extraction from great depth to surface pressure may open and disturb the gas systems.
For example, the Siple Antarctic ice core would suggest that carbon dioxide reached a level of about 330ppm in about 1900. Comparison with the 1960 initial Mauna Loa measurement of 260ppm suggests that either (1) the Siple data is just wrong, or (2) there was a drop of about 60ppm in carbon dioxide level between 1900 and 1960, or (3) it takes 80 some years for the carbon dioxide gas system to close [4]. This discrepancy does not appear to have been resolved by the climate community [5]”
Anyway, just adding it to the mix.
.”Steve Keohane: “You realize 40% of almost zero is ,well, almost zero.”
Do you realise what “partial pressure” is? You, along with various others, have not looked it up have you?
p.s. sorry, forgot to put in the link in my last post – http://www.waragainsttheweak.com/offSiteArchive/www.sfgate.com/ Eugenics and the Nazis — the California connection by Edwin Black
dikranmarsupial says:
April 22, 2012 at 7:24 am
Chuck Nolan: Natural uptake is only in excess of natural emissions because anthropogenic emissions have disturbed atmospheric CO2 levels from their pre-industrial approximate equilibrium level (abou 280ppmv). If we stopped anthropogenic emissions then atmospheric levels would fall, but the rate at which this happened would become smaller and smaller as we approached the new equilibrium, at which point natural emissions and natural uptake would be approximately balance. The jar analogy was only intended to point out why Barts argument was absurd. If you want something more realistic then you would need a differential equation based model, such as the one presented in my paper that I mentioned earlier in the thread.
————————————–
Oh, I get it DM. The earth adjusts CO2 by using “negative feedback.” Thanks. Now that makes sense.
Ed said
Surely more important for Salby’s theory that a 0.8 C rise in temperature causes a 120 ppm increase in atmospheric carbon dioxide is what you get working backwards to the last glacial maximum, which was 4-6 C colder than today. With CO2 at 393 ppm today that gives a negative CO2 concentration at the LGM.
and Myrrh said
Assuming the MWP was hotter or as hot as now and assuming the plant life was as abundant or more so, the increase should be to the whole length of the period from the end of the LIA to present, which may or may not be the end of our particular warming period, compared with beginning to end of MWP.
I thing that either the two of you or I have misunderstood Salby. To me the take away statement from his analysis is :
From the observed behaviour, it is clear that net global emission of CO2 depends intrinsically on temperature.
Now net global emissions are what cause the CO2 concentration to increase. If you increase annual emissions you don’t just increase the level of concentration of CO2 in the atmosphere, you increase the rate at which the level is increasing . If you like, net emissions are like water flowing from a tap into a bath. If you turn the tap on harder (increased net emissions) the water in the bath rises faster. If you turn the tap down a bit (decreased net emissions) the water keeps rising but at a slower rate. This is precisely what Salby’s graphs show. Similarly negative emissions would not mean negative CO2 concentrations, it would simply mean decreasing CO2 concentration (letting some water out of the bath).
Now MWP stands for Medieval Warm Period not Medieval Warming Period. That is, as I understand it, the entire period of four centuries is thought to have been warmer than the last quarter century. ( If Myrrh has evidence that the 10th century was similar in temperature to period immediately following the LIA then I would like to see it.) Given this it follows from Salby’s work that net annual emissions for the whole of the MWP should be at least as high as the last quarter century.
Of course it could be argued that I should have used more recent data. For instance I could have used the period from 1975 to January of this year in which case I would have got an increase of 675 ppm for the four centuries of the MWP meaning the CO2 concentrations at the end of the MWP would have been substantially more than double current levels.
Myrrh’s point on stomata and partial pressure are well taken. If the beginning of the MWP did have (as I assumed) CO2 concentrations at the limit of photosynthesis then the partial pressure of CO2 would have been too low in alpine regions to support plant growth – so we would expect vegetation in the early part of the 10th century to be restricted to low lying areas. Alternatively if alpine regions were indeed vegetated then, it would follow that by the end of the 14th century CO2 levels would have been correspondingly higher than my minimum estimate.
Either way we should be able to identify this massive ramp up of CO2 during the MWP either in ice cores or in the vegetative record. Doing this will establish not only that Salby is right, but that it is possible to enjoy a productive climate even with very high CO2 levels.
Phil. says:
April 20, 2012 at 12:45 pm
Bart says:
April 20, 2012 at 12:32 pm
Phil. says:
April 20, 2012 at 12:25 pm
“But no-one’s doing a static analysis, which is why your comments are wrong.”
That is exactly what they are doing. They are not taking into account the permanent sequestration into land and ocean sinks which are dynamic with unknown response time. Stop embarrassing yourself. You do not understand the argument. I get it.
Unfortunately you don’t! Explain why “the permanent sequestration into land and ocean sinks” are not included in Fn above. We’re talking about what’s happening now and in the near future not in thousands of years time. Permanent sequestration is part of the continuing sinks, Fs, it just isn’t large enough to exceed Fa+Fn.
I notice that you made no attempt to back up the bogus assertion you made above. The Mass Balance equation shows that the addition of CO2 of anthropogenic origin is the source of the growth in atmospheric CO2 and that the sinks are unable to expand fast enough to counter that addition in its entirety. In order to counter that you bring in a bogus argument, by trying to split up the natural sinks to differentiate between the sinks of natural and anthropogenic origin CO2. Such obfuscation is nonsense. In another post you also sought to remove half of the anthropogenic CO2 from the system entirely. You also keep trying to portray the differential balance equation as a static analysis by claiming that the flux terms are constant which is a figment of your imagination, which you have been repeatedly told is not the case, but you continue to trot out the same canard.
It is you who is unwilling to address the arguments but keep trotting out the same old canards time and time again.
By the way mods, almost everyone posting on this subject are doing so anonymously, me, Bart, Smokey, Jimmi, Myrrh etc., why pick out dikran (who ironically is not posting anonymously but pseudonymously)?