Effect of CO2 levels on phytoplankton.
Story submitted by Don Healy
This article opens up a whole new vista into the relationship between CO2 levels, oceanic plant growth and the complex relationships that we have yet to learn about in the field of climate science. If phytoplankton respond like most plant species do, we may find that the modest increases in CO2 levels we have experienced over the last 50 years may actually create a bounty of micro plant growth in the oceans, which would in turn create the food supply necessary to support an increase in the oceans’ animal population.
At the same time, it would explain where the excess atmospheric CO2 has been going; much of it converted into additional biological matter, with only a limited existence as raw CO2.
There may well be a naturally balancing mechanism that explains how the earth was able to survive atmospheric levels of CO2 as high as 7000 mmp in past geologic history without turning into another Venus. Just surmising of course, but this fits with what we know about the response of terrestrial plants to elevated CO2 levels, so it is a plausible theory. Hopefully more studies along this line can clarify the situation.
From the article:
The diatom blooming process is described in the article by Amala Mahadevan, the author of the study and oceanographer at WHOI, as inextricably linked to the flow of whirlpools circulating the plants through the water and keeping them afloat.
“[The study’s] results show that the bloom starts through eddies, even before the sun begins to warm the ocean,” said Ms. Mahadevan.
This study explains the causation of phytoplankton’s phenology—the reasons behind the annual timing of the microscopic plant’s natural cycle—as it is influenced by the ocean’s conditions.
“Springtime blooms of microscopic plants in the ocean absorb enormous quantities of carbon dioxide, much like our forests, emitting oxygen via photosynthesis. Their growth contributes to the oceanic uptake of carbon dioxide, amounting globally to about one-third of the carbon dioxide we put into the air each year through the burning of fossil fuels. An important question is how this ‘biological pump’ for carbon might change in the future as our climate evolves,” said researchers.
WHOI describes the study as being conducted by a specially designed robot that can float just below the surface like a phytoplankton (only much, much larger). Other robots, referred to by WHOI as “gliders” dove to depths of 1,000 meters to collect data and beam it back to shore. Together, the robots discovered a great deal about the biology and nature of the bloom. Then, using three-dimensional computer modeling to analyze the data, Ms. Mahadevan created a model that corresponded with observation of the natural phenomena.
Full story:
http://www.thebunsenburner.com/news/cause-of-north-atlantic-plankton-bloom-is-finally-revealed/
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Eddy-Driven Stratification Initiates North Atlantic Spring Phytoplankton Blooms
Abstract
Springtime phytoplankton blooms photosynthetically fix carbon and export it from the surface ocean at globally important rates. These blooms are triggered by increased light exposure of the phytoplankton due to both seasonal light increase and the development of a near-surface vertical density gradient (stratification) that inhibits vertical mixing of the phytoplankton. Classically and in current climate models, that stratification is ascribed to a springtime warming of the sea surface. Here, using observations from the subpolar North Atlantic and a three-dimensional biophysical model, we show that the initial stratification and resulting bloom are instead caused by eddy-driven slumping of the basin-scale north-south density gradient, resulting in a patchy bloom beginning 20 to 30 days earlier than would occur by warming.
“that the reaction of CO2 increase to temperature consists of a small response on temperature changes for high frequency changes, a huge response on medium frequency changes, as you believe, and again a small response to low and very low frequency changes, where the low frequency changes largely reduce the medium frequency responses.”
A) This is not an uncommon response type – a second order system with non-critical damping behaves this way.
B) Again, you are relying on unreliable and unverifiable ice cores for the conclusion.
Bart says:
July 16, 2012 at 10:13 am
A) The response of CO2 to high frequencies and low to extreme low frequencies is simple first order linear and for inbetween frequencies it should show a second order behaviour?
B) There are a few other proxies for CO2 levels, you don’t like either, which show roughly the same CO2 levels. But let’s look at a short period of the stomata data (which are less reliable over longer time spans):
http://www.ferdinand-engelbeen.be/klimaat/klim_img/stomata.jpg
While the stomata data have their problems, they confirm the trend of the CO2 levels in the pre-Mauna Loa period of the ice cores.
There is a direct overlap between the ice core data from the Law Dome ice cores of ~20 years with the South Pole data:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
Thus at least over a period of 20 years, the ice core data are reliable. But there are many historical measurements made. Most of them are unreliable, as made at places with nearby huge sinks and sources, but some were made on ships over the oceans, which are still seen as reliable places for background measurements today. Besides the low accuracy (of some) of the historical measurements (best performance +/- 10 ppmv), the ice core data are within the range of the seaside measurements.
Thus anyway, for the 1900-1980 period, the ice core data are confirmed by two independent methods, even direct measurements.
Thus one can compare your temperature-only driver with my emissions+temperature change driver with the (8-years smoothed) ice core CO2 levels over the period 1900-2005.
Your temperature-only driven CO2 increase completely fails for the period 1910-1950:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/co2_T_dT_em_1900_2005.jpg
“Thus one can compare your temperature-only driver with my emissions+temperature change driver…”
That’s like saying “thus, we can compare your lightning model to my Thunder God model.” Your model is not physically realizable. There is no mechanism in nature which can perform a least-squares detrend of the unfolding process. It would require a non-causal filter, i.e., a process which weighted data from the future.
Your stomata data has a variability greater than the “error” you claim in the extrapolation. Your Law Dome data “have been corrected for average system enhancement and gravitational fractionation”, i.e., have been adjusted to match the atmospheric sampling. We have no means of verifying that the extrapolation farther back has any validity.
One interesting matter: I expect you look at the close agreement between the calculation based on emissions and the “observations” (I put that in quotes, because pre-1958 are not actual observations, but estimates) and immediately think “they match.” I look at them and immediately think “they match too closely, the books have been cooked.”
Bart says:
July 16, 2012 at 1:50 pm
The Law Dome data are corrected for gravitational fractionation and system enhancement. Both are in the order of 1% of the measurements. Gravitational enhancement is simply because in stagnant air over ~40 years in firn, the heavier molecules and isotopes relatively increase near the bottom of the air column. The enhancement is calculated on basis of the 15N/14N ratio increase near the bottom at closing depth. Thus nothing to do with “adjusting to match atmospheric sampling”. I have no idea what “system enhancement” is, need to reread the work of Etheridge, but a bias of 1% or 3 ppmv is not really problematic in this case…
Further, the stomata data have their problems, including a lack of accuracy, but the trend doesn’t show a change over the high-resolution ice cores + overlap + direct measurements. Thus there is nor reason to expect that ice cores perform worse in the pre-Mauna Loa period than during the overlap. While you miss the response of CO2 to the high frequency temperature changes, the average doesn’t change and a 2-3 year averaging of the temperature data should show the same values. But your solution shows a deviation of up to 20 ppmv in the first period…
But there is another process point that shows the difference between the two approaches:
Whatever what you think about the ice cores, there is a remarkable correlation between the temperature proxy and the CO2 levels. No matter the lags, the filtering over centuries, the problems with the proxy (d18O vs. dD), which may change the ratio between CO2 and temperature… That there is a fixed ratio between absolute CO2 levels and absolute temperature is clear.
Thus CO2 = f(T)
and dCO2 = f(dT)
Our difference starts in the high frequency range: according to you, the high frequency CO2 response is a function of T, while in my opinion the high frequency response is a function of dT.
Both are theoretically possible, as a 2-3 year response to a high frequency change in dT has practically the same form as to a high frequency change in T. Because there are practically no consecutive years without temperature change, it is near impossible to make the distinction over the past 50 years.
The main difference is in the medium frequencies: you approach means that at some point there is a change in response from a function in T to a function in dT (which should be visible by now…). My approach goes fluently from high frequency to very low frequency changes without any change in process type, only some change in coefficients when slower processes come in…
Some error:
according to you, the high frequency CO2 response is a function of T
Must be:
according to you, the high frequency dCO2 response is a function of T
No matter how you slice it, we have no way to confirm CO2 measurements prior to 1958. The stomata data are too variable to be of any use. You appear to present a chance overlap of ~20 years of Law Dome data which has been treated somehow which appears to match the modern record, but this does not mean anything besides that fact that you can take any two slowly varying time series and make them appear affinely similar over some interval. You have no information as to the bounds over which the similarity holds.
You are chasing phantoms. The notion that we had such incredibly good correlation between the temperature and dCO2/dt since 1958 but that relationship simply ended almost immediately prior to that is really wishful thinking.
If CO2 = f(T), then by the chain rule, dCO2 = f'(T)*dT, where f'(T) is the derivative of f(T) with respect to T. So, yes, of course dCO2 is a function of T.
“My approach goes fluently from high frequency to very low frequency changes without any change in process type, only some change in coefficients when slower processes come in.”
It is, as you say, your “approach”. But, nature has no way of implementing your “approach”. It is impossible to remove the trend in real time without phase dispersion. Your “approach” is not feasible in the real world.
BTW, I do not get precisely your relationship with the integrated scaled temperature anomaly. Using trapezoidal integration, my plot looks like this.
I do not want to read too much into that integrated temperature anomaly plot. We do not have any way of confirming whether or how well the temperature-CO2 derivative relationship held prior to 1958.
But, it is a moot question. Since 1958, the relationship has held. And, it explains the increase in CO2 since that time, without any apparent significant impact from human sources.
“The notion that we had such incredibly good correlation between the temperature and dCO2/dt since 1958 but that relationship simply ended almost immediately prior to that is really wishful thinking.”
“We do not have any way of confirming whether or how well the temperature-CO2 derivative relationship held prior to 1958.”
These two statements of mine are in conflict with each other. It is an indicator that I am having trouble expressing my precise thoughts. If I get a chance later, I will try to clarify. But, the bottom line is, as I said above, the relationship has held since 1958.
Bart says:
July 17, 2012 at 8:24 am
It is, as you say, your “approach”. But, nature has no way of implementing your “approach”. It is impossible to remove the trend in real time without phase dispersion. Your “approach” is not feasible in the real world.
Bart, you still get stuck in the nice fit of the trend, which can be obtained for temperature only as good as for temperature variability + part of the emissions. My approach doesn’t need fancy processes which don’t exist in nature and no black hole where the emissions disappear.
It is based on the proven short term, limited capacity of CO2 in the ocean’s surface, which doesn’t allow a continuous sink or source for a limited temperature change, per Henry’s Law. That is where your approach fails, as that is only part of the CO2 variability (in sink capacity). There is no continuous net source from the deep oceans, as there is no temperature connection with the deep oceans and there is no continuous source from the biosphere, as that is a proven sink.
Bart says:
July 17, 2012 at 8:24 am
You appear to present a chance overlap of ~20 years of Law Dome data which has been treated somehow which appears to match the modern record
Everything that doesn’t fit your theory must be manipulated, thus should be discarded…
The CO2 data from ice cores are direct measurements of what was the ancient atmosphere at the moment of bubble closing, be it smoothed over several years. In the case of the Law Dome, smoothed over 8 years and in average 10 years older than in the atmosphere.
The adjustments are based on what can be expected from gravitational fractionation over 40 years. If you don’t like that, then there is a difference of some 6 ppmv (higher) with the atmospheric measurements over the same period. But still, the ice core data are parallel with the atmospheric data in the 20-year period of overlap and in all periods before (the corrections remain the same for the same accumulation rate). Thus anyway, the corrected values reflect the real atmospheric composition of the past, including the period before 1960.
There is no measurable migration in any ice core and even if there was, that would only increase the smoothing over a longer period, without changing the average over that same period. Thus any calculation that tries to backcalculate the CO2 levels of the past must give similar results for the same period.
Your approach already gives a difference of 20 ppmv in 1900 and only gets worse further back in time…
“The notion that we had such incredibly good correlation between the temperature and dCO2/dt since 1958 but that relationship simply ended almost immediately prior to that is really wishful thinking.”
What I meant by that was that, imagining that an entirely different mechanism is responsible for CO2 dynamics both prior to and after 1958 is wishful thinking.
“We do not have any way of confirming whether or how well the temperature-CO2 derivative relationship held prior to 1958.”
What I mean by that is that the model matches the data since 1958. Before 1958, we do not know if the model was valid. Many things can change, sometimes rapidly. A sudden regime change in the temperature of upwelling water from the ocean depths, for example, could easily alter the equilibrium temperature. For example, here, I put in a step change in the equilibrium temperature to the modern value in 1945.
The bottom line is, we neither know with certainty what CO2 was doing prior to 1958, nor do we know the range of years in which the modern relationship between temperature and dCO2/dt held. Thus, the Law Dome estimates of CO2 do not serve to validate or invalidate the model.
Ferdinand Engelbeen says:
July 17, 2012 at 10:41 am
“My approach doesn’t need fancy processes which don’t exist in nature…”
It needs extra-fancy processes. It requires precise removal of a temperature trend which already accounts for all the CO2, and replacement of it with human introduced CO2 in precisely the same measure. And, it must do this while preserving the phase relationships of the higher frequency temperature variation, i.e., it requires a filtering process which relies on future data.
If reaching into future time to affect the present isn’t fancy, I don’t know what is.
Ferdinand Engelbeen says:
July 17, 2012 at 11:06 am
“Everything that doesn’t fit your theory must be manipulated, thus should be discarded…”
I was simply making the elementary observation that a superficial fit over a short time period does not establish agreement outside the interval of observation.
“Your approach already gives a difference of 20 ppmv in 1900 and only gets worse further back in time…”
Again, as I stated above, the model matches the data since 1958. Before 1958, we do not know how far back the model was valid. This is not a trivial matter. You seem to think yourself justified in extrapolating events well beyond intervals of observation. But, in a dynamically changing, some might even call it chaotic, system like the Earth’s climate, there are frequent changes of state which can throw all your tidy little narratives wildly off course.
The only thing we can be sure of is that which we observe directly. We can be sure that, since 1958, dCO2/dt has been remarkably proportional to temperature and, by extension, that temperature has been driving CO2. We can be fairly certain that before that, it was dictated by temperature, too, but not necessarily with the same parameters or simple model.
“There is no continuous net source from the deep oceans, as there is no temperature connection with the deep oceans …”
Ah, yes there is.
Bart says:
July 17, 2012 at 1:11 pm
It needs extra-fancy processes. It requires precise removal of a temperature trend which already accounts for all the CO2, and replacement of it with human introduced CO2 in precisely the same measure.
It doesn’t need extra-fancy processes. Al what is needed is that dCO2/dt is a function of dT/dt and not of T. That is the whole point. dCO2/dt as function of dT/dt explains the high frequency variability of dCO2/dt and the full change in CO2 levels over all frequencies of all time periods, except for the period since the start of the industrial revolution. But since then the human emissions are responsible for the trend part. It needs fancy processes for any natural release to exactly mimic the trend of human emissions…
Just look at the solubility curve of CO2 in seawater, based on Henry’s Law: any change in temperature gives a change in pCO2 of about 16 microatm, where the absolute temperature only changes the factor somewhat. But there is no permanent release or uptake for a fixed temperature change. But with the same Law, if the CO2 levels in the atmosphere exceed the equilibrium, more CO2 is pushed into the oceans, as is observed. Be it that the ocean’s surface has a limited capacity for extra CO2.
Take the same 8 ppmv/°C as observed over ice ages as base for the long-term temperature induced trend, then the error introduced by using the detrended dT/dt as base for the variability around the CO2 trend is ~0.5°C over 45 years or 0.011°C/year or ~0.1 ppmv/year in the rate of change of CO2. Not even measurable.
Bart says:
July 17, 2012 at 1:16 pm
Ah, yes there is.
Except that the THC has the wrong sign for temperature changes: higher temperatures are alleged to give a reduction of the THC turnover speed, the base for catastrophic filmscenarios like “The Day after Tomorrow”. Moreover, the increased CO2 level in the atmosphere gives less natural CO2 releases at the upwelling places by a reduction in delta pCO2 between seawater and atmosphere and an increase in uptake at the downwelling places by an increase in delta pCO2 between atmosphere and seawater… Thus the THC is a net sink for extra CO2, not a source.
a change in pCO2 of about 16 microatm
is of course about 16 microatm/°C. A comparable change of ~16 ppmv in the atmosphere is sufficient to compensate for the change. But as the biosphere works in opposite direction for temperature changes, the real average change is ~8 ppmv/°C. That is about 1 year of human emissions for an upgoing temperature change of 1°C…
Ferdinand Engelbeen says:
July 18, 2012 at 12:35 am
“Al what is needed is that dCO2/dt is a function of dT/dt and not of T.”
The whole point of looking at the data is that it reveals that dCO2/dt is proportional to temperature anomaly.
“Just look at the solubility curve of CO2 in seawater…”
This is what you want to be true. This is where your intuition leads you. But, this is not what the data tells us your intuition is wrong. This is why we do experiments – otherwise, scientists would just sit around and think.
“Take the same 8 ppmv/°C as observed over ice ages…”
By the unreliable and unverifiable ice cores.
“…the increased CO2 level in the atmosphere gives less natural CO2 releases at the upwelling places by a reduction in delta pCO2 between seawater and atmosphere …”
This is begging the question. You are assuming CO2 is rising independently of the upwelling. And, you are not considering that delta pCO2 is only part of the equation. Henry’s Law depends markedly on temperature as well.
If colder water rich in CO2 upwells, it will warm and release that CO2 into the atmosphere. In fact, that could be the mechansim by which dCO2/dt becomes proportional to temperature anomaly. Continuously upwelling ocean water with difference To from the temperature anomaly T causes CO2 to rise proportional to T-To.
I hasten to say, I am not saying this is THE mechanism, just a possibility. Just one of likely many potential unknowns which have not been considered by the mainstream. This is why scientists do experiments to test an hypothesis. Nature is complex, and does not always evolve according to our intuition. You must mold your hypothesis to fit the data, not the data to fit your hypothesis.
“Thus the THC is a net sink for extra CO2, not a source.”
Your intuition again.
Bart says:
July 18, 2012 at 9:06 am
If colder water rich in CO2 upwells, it will warm and release that CO2 into the atmosphere. In fact, that could be the mechansim by which dCO2/dt becomes proportional to temperature anomaly.
Increase of ocean surface temperature since 1960: 0.4°C, subsequent increase in ocean surface pCO2 and hence atmospheric CO2: 6.4 ppmv, whatever the amount of water + CO2 that is upwelling, even if it increased a tenfold. Quantities don’t matter here, surface temperature (and thus CO2 pressure) is what matters.
Observed increase in CO2 levels since 1960: 70 ppmv. Thus in my informed opinion, whatever the THC fluxes are, since 1960 that results in both more sink and less source of CO2 from the (deep) oceans.
I have shown a lot of reasons why the (deep) oceans are not the cause of the increase in the atmosphere, neither is the biosphere, but you simply reject them without real counterarguments. You can theorize any alternative possibility for the increase in the atmosphere besides the human emissions, but they all fail on one or more observations. The hypothesis of dT induced variability + emissions induced trend fits the dCO2 data as good as yours, but also fits all known observations over all periods of time…
Thus again, we are at square one: both on our own viewpoint…
Ferdinand Engelbeen,
The emission rate from a saturated solution is proportional to the rate of increase in temperature, not the temperature. At or near equilibrium there is no change or little change in temperature, thus, little or no emissions. That is why your mass balance (based on a long-term change in “dynamic equilibrium”) produces wrong answers. Yours is not a real argument.
Ferdinand Engelbeen says:
July 18, 2012 at 11:40 am
“…whatever the amount of water + CO2 that is upwelling…”
Incorrect. Cold water from the depths would heat up at the surface, releasing its dissolved CO2, until equilibrium is reached.
fhhaynie says:
July 18, 2012 at 12:25 pm
The emission rate from a saturated solution is proportional to the rate of increase in temperature, not the temperature. At or near equilibrium there is no change or little change in temperature, thus, little or no emissions.
That is exactly what I try to say to Bart. There is a limited outgassing or uptake for a change in temperature, not a continuous flow, as Bart thinks.
But the mass balance must always be obeyed, no matter if that is instantaneous, during fast or slow to very slow changes at equilibrium or not.
Ferdinand Engelbeen ,
My point is that at sources and sinks, there is rarely equilibrium. At the equator, emissions are driven by the around 10 to 15 degree rise in surface temperature as it travels from East to West.
The ocean water near the poles is always a sink and the sink rate is controlled by the rate of delivery to these sinks. In between the ocean surfaces change from sources to sinks. At some points you will find the partial pressure differences to be near zero, but it won’t remain that way for long.
Bart says:
July 18, 2012 at 1:34 pm
“…whatever the amount of water + CO2 that is upwelling…”
Incorrect. Cold water from the depths would heat up at the surface, releasing its dissolved CO2, until equilibrium is reached.
Agreed, the cold deep waters are undersaturated but get oversaturated when heating up at most upwelling places, especially in the tropics. But at the other side of the balance, the downwelling takes CO2 out of the atmosphere. Thus if there is an unbalance between these two (for CO2 fluxes), that will increase with an increased speed of the THC, but the THC is alleged to reduce its speed with increasing temperatures and the increased CO2 levels in the atmosphere push far more CO2 back into the oceans than the small temperature increase does the other way out…
And don’t forget the d13C (un)balance…
Ferdinand Engelbeen says:
July 18, 2012 at 2:56 pm
“the downwelling takes CO2 out of the atmosphere”
But, not generally at the same rate, hence the balance can be altered.
“but the THC is alleged to reduce its speed with increasing temperatures”
We’re talking about a process which takes centuries, and we may well be captive to the conditions which prevailed up to 1600 years ago, such that the water which went down then is coming back up now.
“There is a limited outgassing or uptake for a change in temperature”
But, change in what temperature? The data say that the rate of change of CO2 obeys an approximate relationship of this sort:
dCO2/dt = k*(T – To)
where T is the current temperature, and To is a nominal equilibrium temperature. Let’s look at this more closely.
Suppose we have a closed container which we fill half full of water at ambient temperature T before sealing it. It is at temperature T, and CO2 is partitioned between the air and the water to obey Henry’s Law. If we slightly heat the container, CO2 will outgas from the water and its concentration will increase in the air portion. We can express this relationship as
CO2 =CO2(0) + h*(T – T(0))
where CO2(0) is the concentration before the temperature changes from T(0) to T and h a constant. That expresses the temperature relationship Ferdinand expects, where dCO2/dt = h*dT/dt.
Let’s start over again. At time zero, the concentration of the CO2 in the air portion is CO2(0) and the volume of water is V. We now take a volume dV of cold water at temperature To and exchange it with an equal volume of the warmer water in the container (representing the upwelling of the deep ocean). The cold water will heat up to match the ambient temperature, so it will release CO2 to the air proportional to the temperature change T-To. The CO2 in the air filled portion now becomes
CO2(1) = CO2(0) + h*(dV/V)*(T-To)
Now, suppose we do this repeatedly with a uniform time step dt. Then, we can say
CO2(t+dt) = CO2(t) + (h/V) * dV * (T – To)
But, at each step, the water in the container is becoming progressively more enriched with CO2, so each succeeding addition is a little less, in proportion to the CO2 in the water, which is proportional to the CO2 in the air. Thus, we actually get
CO2(t+dt) = CO2(t) + (h/V) * dV * (T – To) – CO2(t)*dt/tau
where tau is a proportionality constant having units of time. Thus
(CO2(t+dt) – CO2(t))/dt = -CO2(t)/tau + (h/V) * (dV/dt) * (T – To)
which is to say
dCO2/dt = -CO2 / tau + k * (T – To)
where k = (h/V) * (dV/dt). If tau is relatively large, then approximately
dCO2/dt = k*(T – To)
So, here is a relationship which appears approximately to match what the data are telling us. Note that “k” is proportional to the inflow rate, and To is the temperature of the inflow. Neither of these is required to be constant, though they may appear to be approximately so over a finite interval. Furthermore, though tau may be large, over a time span comparable to it, it is going to have a limiting effect.
There are additional paths to pursue from here to include the dynamics corresponding to Henry’s law, the sequestration of carbon in the land and oceans, and the anthropogenic input. I am working on that. But, it is apparent from the data that this is the dominant relationship. You saw it here first.
fhhaynie says:
July 18, 2012 at 6:42 pm
My point is that at sources and sinks, there is rarely equilibrium.
You don’t need an equilibrium to obey a mass balance. Humans emit 8 GtC/year as CO2. There is a measured increase of about 4 GtC/year in the atmosphere. 0.8 GtC is dissolved in the ocean surface (based on measurements of DIC and the overall pCO2 difference + the Revelle factor), 1.2 GtC is taken away by the biosphere (based on the oxygen balance) and the rest of the mass balance of app. 2 GtC thus must be captured by the deep oceans. Other sources and sinks are either too slow or too small to have a medium fast effect.
Thus at this moment there is a total unbalance of 2 GtC between deep oceans sources and sinks, that is more sink than source. No matter what happens underway at the ocean’s surface…
Ferdinand Engelbeen,
The bottom line is that the mass balance method on which you base your arguments is flawed with faulty assumptions and does not agree with observations.
A worthwhile dialogue gentlemen, thank you.
I think the secrets reside in the data. No surprise there.
In 2008 I wrote that dCO2/dt varies ~contemporaneously with temperature and CO2 lags temperature by ~9 months. I referred to Jan Veizer’s papers and think Jan was generally on the right track.
http://icecap.us/index.php/go/joes-blog/carbon_dioxide_in_not_the_primary_cause_of_global_warming_the_future_can_no/
I also observed in 2008 that there was no similar detailed relationship between variations in fossil fuel combustion and atmospheric CO2 levels – the “wiggles” did not correlate.
I was recently fascinated by the observation that the urban CO2 data from Salt Lake City exhibited NO human signature – only the natural daily cycle was apparent.
http://co2.utah.edu/index.php?site=2&id=0&img=30
One wonders if these clever Mormons are all driving Chevy Volts – like the Vikings were driving Volvos during the Medieval Warm Period. 🙂
It seems to me there is evidence that the biosphere is CO2-starved or at least CO2-limited. Since we cannot (except perhaps in winter) see the human signature of urban CO2 emissions AT THE URBAN SOURCE OF THESE EMISSIONS, are these humanmade CO2 emissions being captured close to their source and causing increased biomass in the process? Is there any other explanation? And not all that increased biomass decays in the Spring.
I’m sorry Ferdinand – you are a gentleman and I like you, but I don’t like your mass balance argument. I think atmospheric CO2 concentration is part of a huge dynamic system with biological and physical components on land and in the ocean, and this huge system dwarfs the humanmade CO2 component and is generally unaffected by it. That is what the data says to me.
Variations in biomass (e.g. deforestation and reforestation) may be the huge variable that would make your mass balance equation work better – I agree that we are not exporting CO2 to other planets.
Bart says:
July 18, 2012 at 6:26 pm
But, change in what temperature? The data say that the rate of change of CO2 obeys an approximate relationship of this sort:
dCO2/dt = k*(T – To)
The same data also say that a combination of the emissions and delta T can be responsible for the observed trend ánd the observed variability around the trend. Both show a reasonable good correlation with the observations. Thus the relationship can as good be expressed as:
dCO2/dt = k1*(emissions) + k2*dT/dt
There are two driving forces at work: the emissions and temperature. Both have their influence. In your formula the emissions have negligible influence, even if these are twice the observed increase in the atmosphere. In my formula, both have an influence, but temperature changes mainly on the variability and emissions mainly on the trend.
But let’s have a look at the other observations. As anyway, the result of both approximations must obey the observations. All of them.
– The mass balance.
In all cases the mass balance must be obeyed. No matter can be destroyed or created. Thus the 8 GtC of the emissions must go somewhere. We have quite good measurements of what happens in the atmosphere, the ocean surface and the biosphere. We have little knowledge about what happens with the deep ocean exchanges, but all together, some 2 GtC must be absorbed in a “missing sink”. A lot of sinks do exist for CO2, but most are too slow (e.g. rock weathering), the deep oceans are the most likely sink place.
That means that the ultimate balance of the deep oceans – atmosphere exchange is negative: 2 GtC more sink than source, increasing from ~0.8 GtC in 1960 to ~2 GtC today and a variability in overall sink capacity of +/- 2 GtC/year, be it near always more sink than source over the past 50 years.
– The 13C/12C balance.
The biosphere is a net sink for CO2, thus preferentially 12CO2, thus relatively enriches the atmosphere in 13CO2. Thus that is not the cause of the d13C decline.
The oceans are higher in d13C, as good in the deep oceans as in the surface, than the atmosphere. Thus any substantial extra release of ocean CO2 would increase the d13C ratio of the atmosphere. But we see a d13C drop in the atmosphere as well as in the ocean surface, including the upwelling places, in exact ratio with human emissions.
Your approximation doesn’t fulfill both requirements: even if all human CO2 (including the observed increase in the atmosphere, minus the uptake by biosphere and ocean surface) of nowadays 6 GtC/year is absorbed in the deep oceans, then the 4 GtC extra emissions from the deep oceans to the atmosphere still show an unbalance of 2 GtC more sink than source. Thus the deep oceans are a net sink for CO2, not a source. Moreover, the d13C decline shows that the oceans can’t be the source of the increase in the atmosphere.
BTW, your reasoning doesn’t hold for the continuous emissions in a closed tank:
The cold water will heat up to match the ambient temperature, so it will release CO2 to the air proportional to the temperature change T-To. The CO2 in the air filled portion now becomes
CO2(1) = CO2(0) + h*(dV/V)*(T-To)
When you add a portion of colder water, the pCO2 in the atmosphere of the tank would decrease with the average temperature and get again at the pressure of pCO2 and the old volume of CO2 when T is reached again. Thus at the same temperature as before, there is no net gain of CO2 anymore, as the pCO2 of both water and atmosphere are in equilibrium, no matter how much new water is heated.
It may hold in open air, as there is no equilibrium at all at the upwelling places, but that is as good the case for the downwelling places and the mass balance shows a 2 GtC deficit for the deep oceans…
Allan MacRae says:
July 19, 2012 at 5:37 am
A huge pump delivers a lot of water, some 10,000 liter/minute from a bassin in the base to a fountain. A worker opens a small valve to add water in the main supply line at 10 liter/minute and goes on with some other work, promptly forgetting that he opened the valve. The extra injection is only 0.1% of the main flow, hardly detectable in the normal variability of the main supply. But will that give an increase of the bassin level and even an overflow or not?
Further, have a better look at the Salt Lake city CO2 levels: the second peak between 05:00 and 08:00, while vegetation starts to absorb CO2 under increasing sunlight. Seems rush hour to me…
The same can be seen in the data from Diekirch (Luxemburg):
http://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html
chapter 4.1 where they discuss the diurnal pattern, including the human contribution…