With the possibility of the coldest Super Bowl ever coming this week, this story about CO2 concentration seemed appropriate.
Ryan Scott Welch writes:
Anthony as you know, many people don’t know much about the earth’s atmosphere. For example, when questioned about how much CO2 is in our atmosphere most people give me a guess of somewhere between 30% and 70%. When I tell them that CO2 is only 0.04% or really about 395 ppm (parts per million) they generally look at me as if I was speaking some kind of foreign language. The layman simply cannot convert 0.04% of the atmosphere or 395 ppm into anything they can picture or relate to. In searching for some way to help the layman to understand the earth’s atmosphere, CO2, and the human contribution to atmospheric CO2, I came upon the idea of relating a sample of the atmosphere to something that nearly every person has seen, a football stadium.
So, instead of talking about ppm atmosphere, I talk about seats in a stadium. I put together a presentation using football stadium analogy and it goes something like this.
How much atmospheric CO2 is from human activity? If a football stadium represented a sample of our atmosphere, how many seats would be human caused CO2? The Dallas Cowboys Stadium seats 100,000 for special events.
Each seat represents one molecule of gas in our atmosphere.
Nitrogen is 78% of the atmosphere, Oxygen is 21%, and Argon is 0.9% giving you a total of 99.9% of the atmosphere.
So, where is the CO2? CO2 is a trace gas that is only 0.04% of the atmosphere which in this sample = 40 seats.
But of the 40 seats, or parts per 100,000 of CO2 in the atmosphere, 25 were already in the atmosphere before humans relied on hydrocarbon fuels (coal, gas and oil) leaving 15 seats.
And since humans only contribute 3% of all CO2 emitted into the atmosphere each year (97% is from nature), the human contribution is 3% of the 15 remaining seats in our sample. 3% of 15 is 0.45.
So in our stadium sample of 100,000 seats the human contribution of CO2 is less than half of one seat. That is less than one half of one seat from 100,000 seats in a Dallas Stadium sized sample of our atmosphere is human caused CO2.
[NOTE: per Dr. Robert Brown’s comment pointing out an oversight, this half-seat visualization analogy is on a PER YEAR basis, not a total basis – Anthony]
Here is my presentation uploaded on slideshare.net
http://www.slideshare.net/ryanswelch/how-much-atmospheric-co2-is-from-human-activity-23514995
REFERENCES:
Mauna Loa CO2 data: ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt
Wigley, T.M.L., 1983 “The pre-industrial carbon dioxide level.” Climatic Change 5, 315-320 (lowest value of 250 ppm used)
Increasing Atmospheric CO2: Manmade…or Natural? January 21st, 2009 by Roy W. Spencer, Ph. D. http://www.drroyspencer.com/2009/01/increasing-atmospheric-co2-manmade%E2%80%A6or-natural/
Water Vapor Rules the Greenhouse System, Geocraft, http://www.geocraft.com/WVFossils/greenhouse_data.html
The Carbon Cycle, the Ocean, and the Iron Hypothesis, Figure based on Sabine et al 2004, Texas A&M University http://oceanworld.tamu.edu/resources/oceanography-book/carboncycle.htm
I quite like these analogies, as they tend to give a sense of the idea that is being put forward, however, some of the comments here are also quite disappointing in my view. To infer that the physical properties of all molecules is the same is quite ridiculous, which is where those who say a small amount if cyanide can kill a person is the same as saying a small amount of carbon dioxide is the same physical process are evidentially quite wrong.
If you dropped a hundred dumbells on your foot and then a hundred feathers, do you think you might notice the difference? Not all molecules have the same properties which is where the cyanide example falls down.
In saying that though I actually prefer closer analogies and the one I commonly use is the greenhouse or glasshouse version. If you had a greenhouse that was 35m long by 80 m wide (slightly more than an acre for those using older measurement systems), and if the roof was composed of (~ 2500) glass panels which were 1 m x 1m in dimension, then CO2 would represent just 1 panel. The human component of that CO2 panel would be approximately two hand prints on that one panel of glass.
So, the question is can one pane of glass in a large greenhouse exert a greenhouse effect? Probably not in my view, but what this example and also the one by the author does, is give some perspective on the issue which judging by the output of climate scientists and some of those here, is one thing which is badly missing in this whole discussion
rgb;
Since 100.00% of the warming since the onset of the LIA is easily encompassed in known natural variation, where is this “moderately strong” evidence of human contribution? Badly extrapolated 100+-yr old lab studies don’t cut it. Fail. The Null Hypothesis is that it’s both insignificant and undetectable. The Null stands, not having been refuted at any level of confidence.
Steve B says:
January 27, 2014 at 12:00 pm
Interesting, Steve. So am I correct in saying that according to your theory that the amount of CO2 is so small it’s not worth discussing, it wouldn’t make any difference to the climate if there were no CO2 in the atmosphere?
A simple yes or no will suffice, but explanation is fine too.
w.
Charles says:
January 28, 2014 at 12:20 pm
Dealing just with the GHGs in the atmosphere, the CO2 panel would be one out of about 80.
The main GHG, water vapor, has an average global concentration of about 30,000 ppm. CO2 at around 400 ppm is 1/76 of the combined 30,400 ppm for these two main gases. Methane & other GHGs are at even lower concentrations.
The three single-element main gases which make up over 99% of dry air–N2, O2 & Ar–aren’t much in the greenhouse department.
So a smaller glasshouse would still make your point.
Charles says:
January 28, 2014 at 12:20 pm
Charles, it appears I didn’t make my argument clear. Let me try again.
My argument is that the EFFECT of a substance is in no way correlated with the ABUNDANCE of a substance. Period.
Some things that are abundant have little effect, like perhaps argon in the atmosphere. It’s an inert gas, it doesn’t absorb or radiate in the thermal infrared range at all, plants don’t use it, nothing. There’s much more of it than there is CO2 … but it doesn’t do a dang thing. Abundance is not related to effect.
Other things that are not abundant at all can have huge effect. Much of the tropical ocean, for example, is pretty much a watery desert, nothing grows there. Why? Iron. You add the tinest amount of iron to the ocean mix and life springs up immediately all around you. Once again, abundance is not related to effect, this time in the other direction.
Therefore, you cannot argue that simply because the ABUNDANCE of something is small, that its EFFECT is small. We have a host of counter-examples in both directions to show that that is a logical fallacy.
I mean, if somebody puts a tiny derringer in your face and says “give me your money”, are you going to say “Oh, that gun’s too small to make any difference”. In other words, what I’m saying is size is not related to effect … and that’s what I keep telling my wife …
w.
Seats in Cowboy Stadium are fine, but how many Hiroshima’s is this?
Mickey Reno says:
January 28, 2014 at 12:58 pm
Six Manhattan Islands worth …
w.
Box of Rocks says:
January 28, 2014 at 11:21 am
It is the released photon that is the heart of the GHG/AGW debate. What does it do?? is the million dollar question. But more importantly — HOW MUCH– is produced.
Simplified expression, used in the IPCC 1990 report:
ΔF = 5.35*ln(C/Cinitial)
where ΔF is the increase in downwelling radiation as W/m2 for a 70 km column of air at the CO2 concentration; C the ppmv level of CO2 of interest and Cinitial the ppmv level at pre-industrial times. See Myhre e.a. 1998:
http://go.owu.edu/~chjackso/Climate/papers/Myhre_1998_New%20eatimates%20of%20radiative%20forcing%20due%20to%20well%20mixed%20greenhouse%20gasses.pdf
milodonharlani and Ferdinand Engelbeen are of course correct in their criticism of my simplifying assumption (in the household budget analogy above) that the $97 of expenses stay constant. mildonharlani notes that warming oceans naturally release more CO2 and Ferdinand points out that the biosphere responds to directly to increasing CO2 by increasing the uptake rate. Both can be modeled in the household budget analogy (Ferdinand’s incremental bio-uptake by a tax on the $3 raise and mildonharlani’s incremental oceanic release by interest for the savings account, for example).
I took those out because they added a lot of complexity to the analogy without adding much new insight. Perhaps that was a mistake. More importantly, however, I left those complicating factors out of the analogy because that was not the mechanism being argued in the original post’s final step from 15 seats to 0.45 seats (or in the later stepdown to 0.0759 ppm). The 3% annual increment is what CAUSES the current balance to have increased by 15 seats. There is no mathematically valid reason to multiply those 15 seats by 0.03 again.
Increasing Atmospheric CO2: Manmade…or Natural?
January 21st, 2009 by Roy W. Spencer, Ph. D.
I’ve usually accepted the premise that increasing atmospheric carbon dioxide concentrations are due to the burning of fossil fuels by humans. After all, human emissions average around twice that which is needed to explain the observed rate of increase in the atmosphere. In other words, mankind emits more than enough CO2 to explain the observed increase in the atmosphere.
Furthermore, the ratio of the C13 isotope of carbon to the normal C12 form in atmospheric CO2 has been observed to be decreasing at the same time CO2 has been increasing. Since CO2 produced by fossil fuel burning is depleted in C13 (so the argument goes) this also suggests a manmade source.
But when we start examining the details, an anthropogenic explanation for increasing atmospheric CO2 becomes less obvious.
For example, a decrease in the relative amount of C13 in the atmosphere is also consistent with other biological sources. And since most of the cycling of CO2 between the ocean, land, and atmosphere is due to biological processes, this alone does not make a decreasing C13/C12 ratio a unique marker of an anthropogenic source.
This is shown in the following figure, which I put together based upon my analysis of C13 data from a variety of monitoring stations from the Arctic to the Antarctic. I isolated the seasonal cycle, interannual (year-to-year) variability, and trend signals in the C13 data.
The seasonal cycle clearly shows a terrestrial biomass (vegetation) source, as we expect from the seasonal cycle in Northern Hemispheric vegetation growth. The interannual variability looks more like it is driven by the oceans. The trends, however, are weaker than we would expect from either of these sources or from fossil fuels (which have a C13 signature similar to vegetation).
C13/C12 isotope ratios measured at various latitudes show that CO2 trends are not necessarily from fossil fuel burning.
Secondly, the year-to-year increase in atmospheric CO2 does not look very much like the yearly rate of manmade CO2 emissions. The following figure, a version of which appears in the IPCC’s 2007 report, clearly shows that nature has a huge influence over the amount of CO2 that accumulates in the atmosphere every year.
The yearly increase of CO2 measured at Mauna Loa shows huge natural fluctuations which are caused by temperature changes.
In fact, it turns out that these large year-to-year fluctuations in the rate of atmospheric accumulation are tied to temperature changes, which are in turn due mostly to El Nino, La Nina, and volcanic eruptions. And as shown in the next figure, the CO2 changes tend to follow the temperature changes, by an average of 9 months. This is opposite to the direction of causation presumed to be occurring with manmade global warming, where increasing CO2 is followed by warming.
Year to year CO2 fluctuations at Mauna Loa show that the temperature changes tend to precede the CO2 changes.
If temperature is indeed forcing CO2 changes, either directly or indirectly, then there should be a maximum correlation at zero months lag for the change of CO2 with time versus temperature (dCO2/dt = a + b*T would be the basic rate equation). And as can be seen in the above graph, the peak correlation between these two variables does indeed occur close to zero months.
And this raises an intriguing question:
If natural temperature changes can drive natural CO2 changes (directly or indirectly) on a year-to-year basis, is it possible that some portion of the long term upward trend (that is always attributed to fossil fuel burning) is ALSO due to a natural source?
After all, we already know that the rate of human emissions is very small in magnitude compared to the average rate of CO2 exchange between the atmosphere and the surface (land + ocean): somewhere in the 5% to 10% range. But it has always been assumed that these huge natural yearly exchanges between the surface and atmosphere have been in a long term balance. In that view, the natural balance has only been disrupted in the last 100 years or so as humans started consuming fossil fuel, thus causing the observed long-term increase.
But since the natural fluxes in and out of the atmosphere are so huge, this means that a small natural imbalance between them can rival in magnitude the human CO2 input. And this clearly happens, as is obvious from the second plot shown above!
So, the question is, does long-term warming also cause a CO2 increase, like that we see on in the short term?
Let’s look more closely at just how large these natural, year-to-year changes in CO2 are. Specifically, how much CO2 is emitted for a certain amount of warming? This can be estimated by detrending both the temperature and CO2 accumulation rate data, and comparing the resulting year-to-year fluctuations (see figure below).
Although there is considerable scatter in the above figure, we see an average relationship of 1.71 ppm/yr for every 1 deg C. change in temperature. So, how does this compare to the same relationship for the long-term trends? This is shown in the next figure, where we see a 1.98 ppm/yr for every 1 deg. C of temperature change.
This means that most (1.71/1.98 = 86%) of the upward trend in carbon dioxide since CO2 monitoring began at Mauna Loa 50 years ago could indeed be explained as a result of the warming, rather than the other way around.
So, there is at least empirical evidence that increasing temperatures are causing some portion of the recent rise in atmospheric CO2, in which case CO2 is not the only cause of the warming.
Now, the experts will claim that this is all bogus, because they have computer models of the carbon budget that can explain all of long term rise in CO2 as a result of fossil fuel burning alone.
But, is that the ONLY possible model explanation? Or just the one they wanted their models to support? Did they investigate other model configurations that allowed nature to play a role in long term CO2 increase? Or did those model simulations show that nature couldn’t have played a role?
This is the trouble with model simulations. The ones that get published are usually the ones that support the modeler’s preconceived notions, while alternative model solutions are ignored.
http://www.drroyspencer.com/2009/01/increasing-atmospheric-co2-manmade%E2%80%A6or-natural/
Ryan Scott Welch says: @ur momisugly January 28, 2014 at 2:26 pm
…Furthermore, the ratio of the C13 isotope of carbon to the normal C12 form in atmospheric CO2 has been observed to be decreasing at the same time CO2 has been increasing….
>>>>>>>>>>>>>>>>>..
The Trouble With C12 C13 Ratios
Ferdinand Engelbeen says:
January 28, 2014 at 1:25 pm
Think energy …. British Thermal Units
or more importantly electronvolts.
watts/m^2 –>electronvolts then back to watts/m^2….
Not looking for a ΔF which I take as the change in the field strength.
I could give a rat’s a** about a change in w/m^2 or the change in the strength of the radiative field.
All y’all are saying that CO2 can create a radiative field when it emits photons and that is what I am after.
No one has produced a set of equations centered around CO2 that step through the thermodynamic process of converting one type of radiation to another with a given amount of CO2 in a given volume.
This equation ΔF = 5.35*ln(C/Cinitial) certainty does not do it..
I guess I am barking up the wrong tree and need to visit the local Nuclear Eng Dept. I am sure they have solved a problem similar
Ferdinand Engelbeen says:
January 28, 2014 at 11:27 am
How much carbon is lost to the sea floor in the form of limestone?
I think it would be far more useful to sample the CO2 levels inside the stadium during a game. Wonder if it is anywhere near “equilibrium” with so many humans breathing?
Ryan Scott Welch says:
January 28, 2014 at 2:26 pm
Atmospheric CO2: Manmade…or Natural?
January 21st, 2009 by Roy W. Spencer, Ph. D.
Please don’t cite the whole article, a simple link and a few highlights will do…
But here a link to the mail I sent to Dr. Spencer:
http://www.drroyspencer.com/2009/01/the-origin-of-increasing-atmospheric-co2-a-response-from-ferdinand-engelbeen/
Further:
This is shown in the next figure, where we see a 1.98 ppm/yr for every 1 deg. C of temperature change.
Here Dr. Spencer translates the short-term variation to a long-term trend, but he doesn’t take into account that a limited increase in temperature gives a limited increase in CO2: that is the result of Henry’s law, which shows that for any temperature an equilibrium can be reached between a gas in the atmosphere and in a liquid. That equilibrium only shifts with 17 ppmv/°C for seawater. In real life the increase is maximum 8 ppmv/°C, because the biosphere absorbs more CO2 at higher temperatures…
The short-term reaction of CO2 on temperature is 4-5 ppmv/°C, the long-term reaction is 8 ppmv/°C over the past 800,000 years. Not the over 100 ppmv/°C we see in the past 50+ years…
Just to point out to those that don’t realise yet, the reason that the ‘CO2 is just a trace gas’ argument is irrelevant is that N2, O2 and Argon are transparent to IR Radiation.
It’s only the GHGs that contribute to the GHE..
– and without these gases (mainly CO2 & H2O), the earth would be about 35C cooler
Skip to 32:00 to get to the relevant info
– but the rest of the lecture course is probably worth watching for anyone not up to speed yet…
Box of Rocks says:
January 28, 2014 at 3:07 pm
How much carbon is lost to the sea floor in the form of limestone?
According to the estimates of the carbon cycle, some total 2 GtC/year, but that includes organic carbon too. Much of what sinks as carbonate in the deep oceans is dissolved again before reaching the full depth (the carbonate “horizon”) and resurfaces at the upwelling places. Carbonate sediments are only increasing in more shallow oceans. If I remember well, that is above 2000 meter depth.
Besides that, you have coral growth…
NotTheAussiePhilM says:
January 28, 2014 at 3:45 pm
The estimate I see most often is 33 degrees C, from 255 to 288 kelvin.
But even among GHGs CO2 is a distant second (four per 10,000 dry air molecules v. ~300 average for H2O), & the human contribution less, esp when considering the log effect.
Without assumed positive feedbacks not in evidence (indeed contrary to all observations), CACA can’t happen.
Ryan Scott Welch:
Your post at January 28, 2014 at 2:26 pm poses these questions.
In one of our 2005 papers
(ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005) )
we published 6 models with three emulating a natural cause and the other three assuming an anthropogenic cause of the rise in atmospheric CO2 concentration as recorded at Mauna Loa since 1958.
Each of the models in that paper matches the available empirical data without use of any ‘fiddle-factor’ such as the ‘5-year smoothing’ the UN Intergovernmental Panel on Climate Change (IPCC) uses to get its model to agree with the empirical data.
So, if one of the six models of that paper is adopted then there is a 5:1 probability that the choice is wrong. And other models are probably also possible. And the six models each give a different indication of future atmospheric CO2 concentration for the same future anthropogenic emission of carbon dioxide.
Data that fits all the possible causes is not evidence for the true cause. Data that only fits the true cause would be evidence of the true cause. But these findings demonstrate that there is no data that only fits either an anthropogenic or a natural cause of the recent rise in atmospheric CO2 concentration. Hence, the only factual statements that can be made on the true cause of the recent rise in atmospheric CO2 concentration are
(a) the recent rise in atmospheric CO2 concentration may have an anthropogenic cause, or a natural cause, or some combination of anthropogenic and natural causes,
but
(b) there is no evidence that the recent rise in atmospheric CO2 concentration has a mostly anthropogenic cause or a mostly natural cause.
Hence, using the available data it cannot be known what if any effect altering the anthropogenic emission of CO2 will have on the future atmospheric CO2 concentration. This finding agrees with the statement in Chapter 2 from Working Group 3 in the IPCC’s Third Assessment Report (2001) that says;
Richard
milodonharlani says:
January 28, 2014 at 4:05 pm
The estimate I see most often is 33 degrees C, from 255 to 288 kelvin.
But even among GHGs CO2 is a distant second (four per 10,000 dry air molecules v. ~300 average for H2O), & the human contribution less, esp when considering the log effect.
– right – none of which is relevant to the OP’s post ….
Just to clarify, though, H2O’s GHE is only about 4x CO2’s GHE
– and yes, the important thing is the AGW debate is the size (and sign) of the feedback …
– but my original point still stands
– the OP is irrelevant and misleading ..
Nitrogen, pure 100% N2, has non-zero heat capacity. I can find its specific heat from many sources. How can that be, if it is not a greenhouse gas?
NotTheAussiePhilM says:
January 28, 2014 at 3:45 pm
@ur momisugly 33:07
“holding the heat in..”
Really? The only thingie that the GHGs do is slow the rate of heat transfer from the surface of the earth to space.
“Venus has the grand daddy…”
Is this all the better Yale can do?
They need to take the calcs one step further…
No wonder kids are idiots these days.
Ferdinand, Myhre e.a. is nothing but model. Nobody measured anything. More arm waving than geology…
“Just to clarify, though, H2O’s GHE is only about 4x CO2′s GHE”
Just guessing you’ve garnered this tidbit from a model?
richardscourtney says:
January 28, 2014 at 6:07 am
Box of Rocks:
When something is very unlikely that is not the same as it being impossible. For example, the Sun is very likely to rise tomorrow but it cannot be said that the Sun is certain to rise tomorrow because the world may end tonight.
———————————————
You are scaring some of us with talk like that. How am I going to get to sleep tonight after reading about the possible demise of the world?