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
To all those that are complaining about the analogy not taking into account the cumulative amounts from humans, note that it’s 4% TOTAL from humans. So it’s 1.5 seats TOTAL. The reason is that the half life of man-made CO2 is 4 years. After 4 years, half of it is gone. So man-made CO2 can’t do anything on a global scale.
As a side-note, the amount of CO2 increase we’ve seen indicates an average halflife of 30+ years minimum. Humans can’t produce CO2 with that kind of half life.
If there are cowboys, are there still indians?
@Box of Rocks – who do you think the “Redskins” are? (their most hated rival in the league). 😉
This ‘poison’ thing really amuses me. Warmists always try it on.
What if it were 400ppm of arsenic?…You’d be dead etc etc.
Well I reckon if I was going about my business quite happily with 350ppm of ‘poison’ in me, that gradually increasing it to 400ppm probably wouldn’t do me much harm!
Box of Rocks says:
January 27, 2014 at 2:40 pm
If there are cowboys, are there still indians?
Yes, in Cleveland, but they could not beat the Cowboys in football even with their 2013 defense.
Chuck says:
January 27, 2014 at 2:10 pm
Except CO2 is colorless and odorless among other things.
MrX:
At January 27, 2014 at 2:25 pm you say
Sorry, but No.
You are confusing half life with residence time. They are not the same thing.
Residence time is a function of the mixing rate in and out of the air but half-life (and e-folding time) is almost independent of mixing rate. I explain this as follows.
(a) CO2 residence time is an indication of how long an average CO2 molecule put into the atmosphere stays in the atmosphere (it is about 5 years as determined from isotope studies following nuclear bomb tests).
and
(b) half-life (and e-folding time) is an indication of how the carbon cycle responds to an addition of CO2 into the atmosphere. Estimates are so course that half life and e-folding time are often used interchangeably although they are not the same. (The IPCC seems to use a half life of ~230 years as determined by back-calculation from the Bern Model by me. I estimate it to be ~24 years which is similar to your 30 years).
I explain this as follows.
CO2 is cycled in and out of the atmosphere from several sources notably the oceans. Each year the oceans ‘breath’ CO2 out and in: this is part of what is called the ‘seasonal variation’ in atmospheric CO2 concentration. This ‘breathing’ is very large: each year the oceans emit an order of magnitude more CO2 than all human activity. And each year the oceans sequester a very similar amount of CO2 from the air. But they don’t emit and sequester the same molecules (they emit and sequester a similar number of molecules) each year.
Therefore, a CO2 molecule has a probability of being sequestered as part of that cycling. The residence time of a molecule in the atmosphere is ~5 years. This indicates that it has a ~1:5 chance of being sequestered each year. Put another way, ~1/5 of the CO2 in the air is cycled in and out of the atmosphere as the seasonal variation. Importantly,
RESIDENCE TIME IS A FUNCTION OF THE RATE OF MIXING OF CO2 IN AND OUT OF THE AIR.
So,
~20% of the CO2 in the atmosphere enters the atmosphere each year
and
~20% of the CO2 in the atmosphere leaves the atmosphere each year.
and
these percentages would not change if there were no annual increase to atmospheric CO2 concentration.
But there is an observed annual increase to atmospheric CO2 concentration. In a typical recent year, about 2% of the CO2 emitted to the air (from oceans, biosphere, human activities, etc.) does not return to e.g. the oceans. Put another way the annual CO2 rise is the residual of an inequality in the seasonal variation of the year.
Any annual CO2 rise will affect the annual emission and sequestration of the following year.
For example, if there is more CO2 in the air then that will increase the sequestration of CO2 into the oceans in the following year. The total effect will be a combination of the activities of several interactive mechanisms.
Therefore, the carbon cycle adjusts in response to any change (e.g. temperature rise, the anthropogenic emission, etc.).
The initial effect is an increase (or a decrease) to the CO2 in the air. And this will not make much difference to the proportion of CO2 cycled in and out of the air as the seasonal variation. Therefore, an annual increase (or decrease) to the CO2 in the air makes negligible difference to the CO2 residence time. The residence time is a function of mixing rate so an increase to atmospheric CO2 concentration of 2% only affects mixing rate by ~2%.
But the increase (or decrease) to CO2 in the air alters all the interactive mechanisms which emit CO2 to the air and sequester CO2 from the air.
For purpose of illustration and purely hypothetically, assume the annual rise of one year changed the carbon cycle such that the CO2 in the air was fixed at the new CO2 concentration. Then residence time would still be ~5 years (because mixing rate does not change) but half-life would be infinite (because the new atmospheric CO2 level never falls).
HALF-LIFE (AND e-FOLDING TIME) IS ALMOST INDEPENDENT OF MIXING RATE.
IT IS A FUNCTION OF HOW THE CARBON CYCLE RESPONDS TO A CHANGE.
The half-life is a function of how the carbon cycle responds to a change. And nobody knows how the carbon cycle actually responds to a change so there are many possible responses that can be imagined and modeled. Hence, the great difference between the IPCc estimate of ~230 years and my estimate of ~24 years).
n.b. the numbers are simplified for clarity in the above illustration.
I hope this explanation is adequate and sufficiently clear.
Richard
Jimbo @12.11
“Also point out that greenhouse growers regularly pump in over 800ppm.”
The level to which the CO2 concentration should be raised depends on the crop, light intensity, temperature, ventilation, stage of the crop growth and the economics of the crop. For most crops the saturation point will be reached at about 1,000–1,300 ppm under ideal circumstances.
Liquid carbon dioxide has become popular for many growers [ as opposed to natural gas and propane] even though it is usually more expensive. The main advantages of using liquid CO2 include purity of product, no concerns about crop damage, nor heat or moisture production, better control of CO2 levels and the flexibility to introduce the CO2 within the plant canopy at any time.
When natural gas, propane or kerosene is burned, not only CO2 is produced, but also heat is generated that can supplement the normal heating system. The relative humidity will increase by about 3%–6% when using natural gas provided the greenhouse temperature is not affected from the heat generated by the burners. Typically, when the temperature is raised by 1°C there is no effect on the relative humidity……………….This does not happen with liquid carbon dioxide!!
And it is important to have an adequate distribution system. The distribution of CO2 depends mainly on air movement within the greenhouse(s), as CO2 does not travel very far through diffusion. For instance, when a single source of CO2 is used for a large surface area or several connecting greenhouses, a distribution system must be installed, to evenly distribute the CO2 in the greenhouse especially when flue gas CO2 or liquid CO2 is used.
Huge parallels here with the earths natural system methinks.
Box of Rocks says:
January 27, 2014 at 2:40 pm
Yes, but not much longer if the legion of the perpetually offended get their way.
Let’s all reconcile and be friends again.
It’s a funny and uncertain world we live in. Climate sensitivity is worse than we thought. Water vapour will go viral any time soon.
The analogy I like to use is. I have borrowed one million dollars from you. I offer to pay back 400 dollars. Would you be happy with this deal? If not, why not? Is 400 dollars an insignficant amount to the total?
Though RGB and others are correct in their critiques of the article, I feel they are missing the bigger point – the poor scientific knowledge in the better part of society. Yes, the issue of AGW is very complex and which is the precisely the problem when trying to explain the issue to the less scientifically literate. Without a foundation of simple knowledge, complex issues are won more frequently upon emotion. I ran into this problem when publically speaking on radiation issues. It is a huge problem. The only way the ignorance can be overcome is to explain things in simplistic, 8th grade terms. The issue, in this case CO2, has to be explained in simplistic terms. If one’s explanation gets too complex and much further beyond an 8th grade explanation, the average person’s eyes will glaze over and the explanation will be lost. People are not stupid (as a rule), but once the explanation is lost to them, they will revert to an emotional response instead of an intellectual response. The alarmists are far better at evoking that emotional response. I would not hesitate to employ the analogies in this article when talking to a science illiterate plus I would add some emotional facts to counter the alarmists’ emotional facts.
I am in complete agreement that the 3% step was a step too far in the picture …. according to current theory.
However, it seems rather interesting that a system which remained in balance at a very precise level for many hundred thousand years is completely unable to cope with an additional 3% loading per year ….. the balance must have been delicate indeed …. or, there is a lot more going on than simple addition.
What about tampering.
We are about to destroy our biosphere with co2 fertilization. A greening planet does not take up co2. Arid areas are indeed getting drygreen. We are doomed.
glenncz says:
January 27, 2014 at 11:22 am
“. . . the 400-150=250 ppm . . .
The 150 used seems to be your personal choice for the concentration of CO2 in the pre-industrial atmosphere. Many think this should be about 280. Others think it was quite variable, maybe 320. At the following link, see the table and ref. #6.
http://cdiac.ornl.gov/pns/current_ghg.html
I realize the choice of numbers in your equation have nothing to do with the issue you raise but many plants perform poorly at around 220 and 150 appears to be near the minimum needed for survival. So I’ve read.
Willis Eschenbach says:
January 27, 2014 at 10:59 am
“Your argument seems to be, CO2 is only a trivially small part of the atmosphere, so we can ignore it.
However, compare it with something like say cyanide.”
Interestingly, this suggests to me a case that could have been made against the EPA’s CO2 toxic pollutant finding. One breath of air is ~ l litre which weighs 1.2 grams and contains ~ 0.5mg of CO2 and presumably we breath it mostly all back out again. A green mamba bite has ~100mg of venom in one shot. Mortality is high but some figures put mortality without treatment at 80%. Cyanide, arsenic and the rest are of similar toxic levels. I think if the court had been presented with these comparisons the legal support for the EPA’s position would have fallen apart.
I would say that the Author is in the ballpark with the right numbers, even the half a ppm bit. I would like to point out that it is generally considered that CO2 is fairly well mixed, but the total amount varies at different points of the year. On average it goes down for five months then up for seven months with a net of 2PPM increase a year at Mauna Loa observatory which has the longest record of measurements. So the fact that it actually goes down says that the system is capable of absorbing all the CO2 produced for a set period of time, but not all the time. The swing (around 8PPM with a 2PPM residual per year for the recent bit of the pause) . During this time our generation of CO2(from breathing to driving) is fairly constant, it certainly doesn’t decrease for 5 months out of the year. The authors reasoning is valid because we think that the Anthropogenic output of CO2 is small compared to the natural sources, if it wasn’t, there would be a steady clime in the atmospheric CO2 concentration. AGW folks include in their Anthropogenic calculations such things as domesticated animals including cows which I feel is a bit of a stretch since there would likely be more animals about if we weren’t here to add to the mess as well as more insects. But anyways excellent post!
Thank you for your response at:
richardscourtney says:
January 27, 2014 at 12:41 pm
You cover most of what I question.
From the OP:
“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.”
Weren’t we at about 250 ppm at the end of the LIA?
Did the increase from that level only begin (and be directly related to) anthropogenic emissions?
Wasn’t some of the increase natural even before we humans began contributing measurably?
Around 1955 the CO2 level was about 310 ppm. If we are supposedly contributing measurably to the increase since then, 400 – 310 = 90 ppm (9 seats in the example), so at most we could be responsible for 3% of 9, or .27 of a seat (assuming responsibility of the entire 90 ppm).
It’s even less worse than we thought.
🙂
A thought which I didn’t see from other commenters on this thread:
A rough estimate of the air volume inside Cowboy Stadium is: 200 m long x 150 m wide x 50 m high = 1,500,000 m3. At .0004 concentration, that includes 600 m3 (600,000 liters) of CO2.
A rough estimate of the amount of CO2 exhaled during a 3-hour game by each person is 180 grams (21,600 respirations/day @ur momisugly .045 CO2 @ur momisugly 750 ml/breath ~ 90 liters CO2 content, per person, during the game.; x 100,000 persons = 9,000,000 liters = 9,000 m3. If all that CO2 stays in the stadium (conceivable, since it’s heavier than air), we now have 9,600 m3/1,500,000 m3 = 0.0064 concentration of CO2.
Even if these back-of-the-envelope calculations are off by an order of magnitude – why doesn’t the stadium burn up during a game, just from all those people there? Explain that, CAGW freakos.
richardscourtney says:
January 27, 2014 at 1:04 pm
Ah, yes. Metric football.
Must have been invented by the French and regulated by the EU. (Claims to be a sport, but there is no contact, the rules make no sense but it is highly regulated, and there’s a lot of running around but not much scoring…)
disappointed says:
January 27, 2014 at 11:42 am
In my mind it had better be removed.
———————————————–
I see several others who voice a similar thought, but doesn’t the great comment section rectify the need for removal with it,s diverse and open conversation that sheds light on reasons pro and con as to the value of the post?
I noticed that too.
I suspect that the author was just trying to point out how small a percentage co2 is compared to peoples’ beliefs. This is a crucial point. You will not believe me when I tell you that people have told me that co2 is the most important greenhouse gas!
The IPCC says no.
You just don’t want to sit in front of the guy who ate the Nachos El Grande and drank a few beers (or behind him for that matter).
rgbatduke says:January 27, 2014 at 10:46 am
Willis Eschenbach says:January 27, 2014 at 10:59 am
et al
Forget about the 1/2 seat for a moment.
Suppose the CO2 content goes from 40 to 50 seats per 100,000. Field experiments and lab experiments have shown that biomass and crop production goes up 25% to 30% as a direct response to CO2 enrichment.
Conclusion: there will be 25% more pop corn!!!!
Regarding Ryan Scott Welch half seat comparison, so what??? It is irrelevant. We are at about 400ppm with 16 years of a surface temperature standstill;. How much ‘dangerous warming’ will we have at 800ppm??? Is it possible it would be beneficial warming???? Where is the evidence that 800ppm has resulted in net damage to the planet?
I suspect that by the end of this century our main worry will not be about co2 but aging populations, fertility rates and production / pensions. Our other worry after the end of this century could be about falling global population. Check out the fertility rates of Latin American countries, the EU, etc. Co2 insanity, the real worry will be carried out by our children and grandchildren. I hope I’m wrong.
http://www.bbc.co.uk/news/magazine-24303537
http://www.aei-ideas.org/2013/05/population-bomb-no-theres-been-a-massive-global-drop-in-human-fertility-that-has-gone-largely-unnoticed-by-the-media/
http://yaleglobal.yale.edu/content/global-population-10-billion-not-so-fast
JohnWho:
re your question at January 27, 2014 at 3:37 pm.
I am openly stating that I am avoiding your question because I don’t want to side-track the thread, but I will summarise my view and suggest how to find what you really want.
I am certain that the “accumulation” argument is wrong because it is refuted by the dynamics of atmospheric CO2, and I accept the indication from stomata data that atmospheric CO2 concentration variation was similar to now in pre-industrial atmospheric times. But that does NOT mean I think the recent CO2 rise is anthropogenic or is natural in part or in whole. The recent rise is probably adjustment of the carbon cycle system towards an altered equilibrium. But the cause of that change to the equilibrium state of the carbon cycle is not known: the cause is probably natural but it could be addition of the anthropogenic emission.
That is an introduction to my views.
For a more full answer to your question please use the WUWT Search facility and search for Salby. Read the threads of the searched articles taking especial note of comments by Ferdinand Engelbeen, Bart and me. Between the three of us you will get the full range of views.
And that is all I am willing to say on the matter in this thread. Sorry.
Richard