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 always thought World Series was about rounders. Must be another one.
Matt,
For all practical purposes, water vapor is an atmospheric gas. It can exist as liquid water droplets, or as a gas. A single molecule of H2O acts as a gas, just like a molecule of CO2.
The amount of water vapor in the atmosphere varies, from ≈1% – 4%. It emits and absorbs solar energy, just like CO2 and other gases do.
Hoser:
Thankyou for your point to me at January 27, 2014 at 7:01 pm.
I refer you to the post of Bill Bill H which answers your point. It is at January 27, 2014 at 7:04 pm here
The half-life of atmospheric CO2 is at least as important as climate sensitivity and we have estimates of its value with a range which is nearly two orders of magnitude.
Richard
Well, I have missed most of the discussion, as I was absent yesterday… But let’s look at the facts.
Robert Brown’s comment and additional comments by WUWT regulars like Willis and others have already pointed to the main flaw in the last part, but the early parts are quite interesting to give people a comparison of the quantities involved, be it that that doesn’t give any idea about its effects…
To begin with, here a comparison between the accumulated emissions from humans since ~1900 and the accumulation in the atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg
where the CO2 values before 1960 are from ice cores and from 1960 on from Mauna Loa, human emissions are from fossil fuel sales (taxes!) and burning efficiency of the different fuels.
There is an almost perfect correlation between human emissions and the increase in the atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2.jpg
Far less impressive for temperature and CO2 accumulation:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_co2_1900_2012.jpg
As usual there is a lot of confusion between the “only 3% per year” and the accumulation in the atmosphere. As about half the quantity (not the original molecules) of the human addition is removed per year, the real accumulation is:
~160 GtC/year in (97% natural, 3% human) – ~155 GtC/year out (whatever the natural/human composition) = ~5 GtC/year (~2.5 ppmv/year) increase in the atmosphere.
Simply said, the combined input is larger than the natural output. The latter is increased, compared to the past, because of the increased CO2 pressure in the atmosphere over the past 50/160 years. 160 years ago there was little change in CO2, according to high resolution (~ a decade) ice cores. Even the MWP-LIA transition of ~0.8°C only caused ~6 ppmv change over a period of ~200 years with a lag of ~50 years after the temperature drop:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
Thus the current increase of ~0.6°C is only good for a ~5 ppmv increase in CO2 from the 110 ppmv increase since 1850…
The current decay rate of CO2 in the atmosphere is ~50 years:
we are 232 GtC (110 ppmv) above the pre-industrial equilibrium. That causes an extra removal of ~4.5 GtC/year (2.15 ppmv/year) of CO2 somewhere in nature. That gives an e-fold decay rate for the extra CO2 of:
232 GtC / 4.5 GtC/year = ~52 years. Or a half life time of ~40 years.
That is too slow to remove all human CO2 every year, but more than fast enough to keep CO2 on track after the historical temperature changes over the many millennia of the past few million years of these glacials/interglacials period.
What about the effect of the increase? As far as seen in the past, the effect of more CO2 on the earth’s temperature / heat balance is very modest and very modest in modern times: the current standstill in temperature is performed with record emissions and levels of CO2. That means that, if natural oscillations (ocean currents?) can stop the warming by the extra CO2, natural oscillations also can be responsible for (most of) the warming in the previous period…
Several people (including the author of the original post) still seem to be confused by the criticisms of that final jump from 15 seats to 0.45 seats. Willis got close with his analogy to savings but I think not close enough. A better analogy would be to talk about your household income. Say that you earned $97 per year. Your budget was on average perfectly balanced, spending that same $97 each year. There was some variation within the year but your savings went up and down by very little each year. The residence time of an individual dollar in your savings account is irrelevant. If you start with a large balance, the calculated residence time of a bill in the bank could be years. If you have no savings, that dollar could circulate out of your bank account in days. It doesn’t matter, though, because your budget is in balance. For the sake of argument, let’s start our saving account with a balance of $280.
Now you get a $3 raise. But being a good saver (and in our fictitious world with no taxes), your spending stays at $97 per year. Your savings will start to go up by $3 per year and ALL of that increase is a consequence of your one raise. This will remain true even though the dollars from that incremental $3 still circulate through your account almost exactly as fast as they did before the raise and even though the individual dollars can not be distinguished by their source.
The more recent comments (which get to an annual contribution of 0.0759 ppm) compound the error by reducing the anthropogenic contribution by 97% a second time. You don’t get to divide the number twice. That would be like saying that the $3 per year raise would only increase your savings by $0.09 per year. It confuses the incremental savings with the total household budget.
JoNova (I think it was) had this simple analogy posted a couple of years ago:
Imagine 1 kilometre of atmosphere and we want to get rid of the carbon pollution in it created by human activity.
Let’s go for a walk along it.
The first 770 metres are Nitrogen.
The next 210 metres are Oxygen.
That’s 980 metres of the 1 kilometre. 20 metres to go.
The next 10 metres are water vapour. 10 metres left.
9 metres are argon. Just 1 more metre.
A few gases make up the first bit of that last metre.
The last 38 centimetres of the kilometre – that’s carbon dioxide. A bit over one foot.
97% of that is produced by Mother Nature. It’s natural.
Out of our journey of one kilometre, there are just 12 millimetres left. Just over a centimetre – about half an inch.
That’s the amount of carbon dioxide that global human activity puts into the atmosphere.
Brian R:
Your post at January 27, 2014 at 9:42 pm says in total
Not trying to slam you but your two points contradict each other.
As rgbatduke says, the physics of CO2 in the atmosphere are quite clear.
This does NOT mean “the climate models wouldn’t be so wrong”
because
we do NOT understand how CO2 reacts within the atmosphere system or – to be precise – what the atmosphere does when the physics of increased CO2 operate.
Richard
mikerossander says:
January 28, 2014 at 2:56 am
You overlook the complicating factor that warming oceans naturally release more CO2 to the air, so the unchanging $97 spent annually in your analogy doesn’t hold.
The problem is that no one knows how much CO2 would be in the air at present T without human contribution, so dwell time of natural & human gas does matter very much.
Carbon500 says:
January 27, 2014 at 10:51 pm
As I never cease to point out, why hasn’t anyone in ‘climate science’ conducted an experiment (a real one, not a computer calculation) to show the effects of CO2 at varying concentrations in the presence of water (also at varying concentrations) and other atmospheric gases?
As far as I know, there is no reaction between CO2 as gas and water as vapour, or hardly of interest. Of course, some CO2 will dissolve in water drops when water condenses out in clouds and rain, but that are very low concentrations, just over a mg/kg at the low CO2 partial pressure in the atmosphere and hardly changes the levels in the atmosphere at the clouds level or the surface where the rain falls down.
But about the effect: much is known of what happens to absorbance/emissitivity of any mixture of CO2, water vapour and methane in the atmosphere from laboratory measurements: HITRAN of the military produced line by line transmission/absorbance effects of such mixtures at many atmospheric pressure levels, which can calculate the total absorbance/transmission over any layer of the atmosphere.
Less accurate, but also less calculation intensive is MODTRAN, which calculates the same for less resolution. That is even on line and can be used to experiment with the effect (before any feeedbacks) of CO2 on temperature, be it that it seems to be off-line for the moment.
The Modtran calculation model was verified by satellite measurements of outgoing IR radiation:
http://climatemodels.uchicago.edu/modtran/modtran.doc.html
Anyway, CO2 is mainly active in the bandwidth where water vapour is not active…
But the main problem, as usual, is the behaviour of clouds on the whole IR budget.
milodonharlani says:
January 28, 2014 at 3:12 am
You overlook the complicating factor that warming oceans naturally release more CO2 to the air, so the unchanging $97 spent annually in your analogy doesn’t hold.
We know perfectly well how much CO2 will get in the atmosphere from warming oceans: 17 ppmv/°C, according to Henry’s Law:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/upwelling_temp.jpg
That is the dynamic increase of CO2 caused by an initial jump in temperature: more CO2 release in the tropics, less uptake near the poles. But the resulting increase of CO2 in the atmosphere has the opposite effect, until at 17 ppmv extra CO2 in the atmosphere the whole dynamic process is again in equilibrium.
But as biolife acts the other way out (increasing temperature = increasing uptake), the real world effect is 4-5 ppmv/°C short term (seasonal, 2-3 years variability) up to 8 ppmv very long term (decades to multi-millennia), here for the Vostok ice core (420,000 years):
http://www.ferdinand-engelbeen.be/klimaat/klim_img/Vostok_trends.gif
It would be very remarkable to find a natural process that:
1) mimics the human emissions at the exactly the same ratio and timing.
2) results in the same changes of 13C/12C and 14C/12C ratio’s
3) increases the CO2 levels with over 100 ppmv/°C
4) that does INcrease the residence time of CO2 in the atmosphere over the past 50 years
Any substantial increase of CO2 emissions from the oceans will violate points 2 and 4 and is near impossible for point 3.
Ryan………….a good way to get a visual perspective of the amount of CO2 in the atmosphere is to make up a thousand piece jigsaw. I think the amount is less than 1/2 of one piece.
Ferdinand Engelbeen says:
January 28, 2014 at 3:43 am
Ferdinand, it is reasonable for you to have summarised your view because I did the same so that ballance is appropriate in this thread.
But I strongly commend everybody to avoid side-tracking this thread with discussion of the carbon cycle.
This thread is about effective but not misleading communication of climate information to the public.
That communication requires accuracy, humour and honesty. It is important.
Richard
Ferdinand Engelbeen says:
January 28, 2014 at 3:22 am
Please tell me where I’m wrong, but this appears to show about 57% overlap between water vapor & CO2 IR absorption (sorry about table formatting):
http://irina.eas.gatech.edu/EAS8803_Fall2009/Lec6.pdf
Table 6.3 Main Visible and near-IR absorption bands of atmospheric gases
Gas Center
ν (cm-1) (λ(µm))
Band interval
(cm-1)
H2O 3703 (2.7)
5348 (1.87)
7246 (1.38)
9090 (1.1)
10638 (0.94)
12195 (0.82)
13888 (0.72)
visible
2500-4500
4800-6200
6400-7600
8200-9400
10100-11300
11700-12700
13400-14600
15000-22600
CO2 2526 (4.3)
3703 (2.7)
5000 (2.0)
6250 (1.6)
7143 (1.4)
2000-2400
3400-3850
4700-5200
6100-6450
6850-7000
That’s without taking into consideration strength of absorption or the most frequent radiating temperatures of the earth.
Sorry that jigsaws are a bit more boring than the footy,
dbstealey,
that is nonsense. A single molecule of CO2 in the atmosphere does not behave like a gas because of it’s microscopic makeup as a single molecule, it behaves like a gas because it is !! a gas at any relevant temperature.
A single molecule of solid CO2 does not become gaseous only because it is single.
Likewise, who says that water water in the atmosphere consists of individual molecules? It is vapor.
Why would they show 1% of Argon but not 4% of water? Because it is about gases. It it weren’t about gases, why not include soot, dust etc as well?
matt – Chemistry 101 – Definition of MOLECULE 1 : the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms
http://www.merriam-webster.com/dictionary/molecule
See the bolded part? You are wrong.
Ferdinand Engelbeen says:
January 28, 2014 at 3:43 am
I don’t suppose that all or even most of the alleged roughly 120 ppm increase in CO2 since c. 1850 is attributable to humans. As in prior discussions with you, I’m willing at least for purposes of discussion to go with 100 ppm, although actual anthro component might be less than that.
You are quite sure of the natural releases & sinks, but IMO science can’t be certain yet even to have discovered all the sinks.
Matt says:
January 28, 2014 at 4:19 am
Water vapor is a gas. CO2 concentration is reported for dry air because water vapor content of the atmosphere varies so much, from over 4% in the tropics to very little at the poles.
milodonharlani says:
January 28, 2014 at 4:10 am
Please tell me where I’m wrong, but this appears to show about 57% overlap between water vapor & CO2 IR absorption (sorry about table formatting)
The figures you give ar for visible and near IR, which are important for incoming sunlight, where water vapour is active and completely overlaps the few CO2 bands. But the GHG effect is in the outgoing farther IR bands…
A nice overview of absorption bands is here, from slide 21 on, including the theoretical background for the greenhouse gases active in the outgoing IR bands:
http://ist-socrates.berkeley.edu/~budker/Physics138/Alyssa%20Atwood%20Atm%20Spec5.ppt
The main CO2 absorption band is at 660 cm-1 (15 μm), where water is not active.
But even so, in dry circumstances (polar, desert) other bands may become important.
Willis, I did state what I thought the point of Mr. Welch’s article. Quoting myself: “It seems to me Mr. Welch was merely, and graphically, showing the disconnect between the common misconception about atmospheric CO2 vs. the reality.” My main reason for replying to your reply was to push back against your cyanide analogy.
Of course, I think you are using valid and sound reasoning when you seem to be considering Mr. Welch’s full motivation. I have often used an imagined pay stub to demonstrate just how little CO2 is actually in the air. “The median weekly pay check is something like $1,000. If there was a ‘carbon tax’ in there that equaled the percentage of CO2 that’s in the air, it would only be 40 cents!” I’ve never broken the 40 cents down further, though. So, when someone else does, it seems obvious they are attempting to make a further point.
And, I guess that means I’m now walking back the word “merely” in my original reply!
Ferdinand Engelbeen says:
January 28, 2014 at 4:53 am
Thanks.
Clearly CO2 is relatively more important at the poles, so impoverished of water vapor.
dave ward says:
January 28, 2014 at 3:10 am
97% of that is produced by Mother Nature. It’s natural.
And there you go wrong: many forget that 98.5% of the mix is removed by Mother Nature in the same year. That makes that 1.5% is accumulating in the atmosphere… Humans are contributing 3% to the input, while the removal of the human-natural mix is 1.5% per year (of which currently some 10% or 0.15% is of human origin). Thus make the correct sums.
I think that most housewives have no problem with knowing what contributes to the increase of their household budget, if that happens in the same way as the above ins and outs…
richardscourtney says:
January 28, 2014 at 3:11 am
Brian R:
Your post at January 27, 2014 at 9:42 pm says in total
Not trying to slam rgbatduke, but if the physics of CO2 in the atmosphere are quite clear, then the climate models wouldn’t be so wrong. I agree that we know how CO2 reacts with both short wave and long wave IR. But would disagree that we understand how CO2 reacts within the atmosphere system.
Not trying to slam you but your two points contradict each other.
As rgbatduke says, the physics of CO2 in the atmosphere are quite clear.
This does NOT mean “the climate models wouldn’t be so wrong”
because
we do NOT understand how CO2 reacts within the atmosphere system or – to be precise – what the atmosphere does when the physics of increased CO2 operate.
Richard
**************************************************************
**IF***
The physics of CO2 in the atmosphere are quite clear then give me a calculation that I can use that shows the CO2 can warm a control volume of 1 cubic foot of air 1 degree F. in 60 seconds
It is that simple …
That is the GHG theory right? GHG warm the atmosphere, right. Should be a simple thermodynamic calc an entry level Mech Eng can do.
Last time I counted there were 40 cheerleaders on the squad, so CO2 is about as rare in the air as a Dallas cheerleader in a full stadium.
Box of Rocks says:
January 28, 2014 at 5:24 am
The physics of CO2 in the atmosphere are quite clear then give me a calculation that I can use that shows the CO2 can warm a control volume of 1 cubic foot of air 1 degree F. in 60 seconds
The first observations were made by John Tyndall in 1859 who could show the increased effect of IR radiation by adding CO2 above a flame.
And have a look at a modern equivalent: CO2 lasers, quite effective in using its excitation energy to beam a lot of energy into a small bundle:
http://en.wikipedia.org/wiki/Carbon_dioxide_laser
The greenhouse effect of CO2 is rather weak: a 70 km column of air increasing its CO2 level from 290 to 580 ppmv will absorb 4.7 W/m2 more IR. To bring the outgoing radiation back to the same value, you need to increase the earth’s temperature some 0.9°C. All the rest is hype: positive feedback in the models increase that to 1.5-4.5°C, but these are the models that all fail to explain the current “pauze”…
Box of Rocks:
re your request for clarification from me which you provide at January 28, 2014 at 5:24 am.
Sorry I was not sufficiently clear. I will try again.
The radiative physics which provides the greenhouse effect (GHE) is clear and understood.
BUT the complex Earth’s climate system is little understood.
We know as certain fact that adding CO2 to the atmosphere will increase the GHE to raise global temperature ALL OTHER THINGS BEING EQUAL. But all other things are not equal in the complex Earth’s climate system: any change to one thing can change everything else.
So, the direct raise to global temperature from doubling atmospheric CO2 from present level would be about ~1.2°C if all other things remained unchanged. But things will change in the climate system and that may increase the raise in temperature (positive feedback) or lower the raise in temperature (negative feedback).
I think the feedbacks are negative so the raise to global temperature from doubling atmospheric CO2 from present level would be less than 1.2°C.
The IPCC thinks the feedbacks are positive so the raise to global temperature from doubling atmospheric CO2 from present level would be more than 1.2°C.
Nobody knows the truth of this but there is much evidence to support my view (some is stated above in this thread). I COULD BE WRONG.
As temperature rises then some change may occur to the climate system that provides a very, very large positive feedback which would provide a very, very large increase to global temperature. This is not likely but it is possible because the complex Earth’s climate system is little understood.
Please note that Willis Eschenbach makes a similar point about emergent properties (e.g. storm formation) to argue that as temperature rises then some change may occur to the climate system that provides a very, very large negative feedback which would provide a very, very small increase to global temperature.
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.
Richard