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Atmospheric Residence Time of Man-Made CO2
Potential Dependence of Global Warming on the Residence Time (RT) in the Atmosphere of Anthropogenically Sourced Carbon Dioxide
Robert H. Essenhigh
Department of Mechanical Engineering, The Ohio State University, Columbus, Ohio 43210
Energy Fuels, 2009, 23 (5), pp 2773–2784
DOI: 10.1021/ef800581r
Publication Date (Web): April 1, 2009
Copyright © 2009 American Chemical Society
The driver for this study is the wide-ranging published values of the CO2 atmospheric residence time (RT), τ, with the values differing by more than an order of magnitude, where the significance of the difference relates to decisions on whether (1) to attempt control of combustion-sourced (anthropogenic) CO2 emissions, if τ > 100 years, or (2) not to attempt control, if τ 10 years. This given difference is particularly evident in the IPCC First 1990 Climate Change Report where, in the opening policymakers summary of the report, the RT is stated to be in the range of 50−200 years, and (largely) on the basis of that, it was also concluded in the report and from subsequent related studies that the current rising level of CO2 was due to combustion of fossil fuels, thus carrying the, now widely accepted, rider that CO2 emissions from combustion should therefore be curbed. However, the actual data in the text of the IPCC report separately states a value of 4 years. The differential of these two times is then clearly identified in the relevant supporting documents of the report as being, separately (1) a long-term (100 years) adjustment or response time to accommodate imbalance increases in CO2 emissions from all sources and (2) the actual RT in the atmosphere of 4 years. As a check on that differentiation and its alternative outcome, the definition and determination of RT thus defined the need for and focus of this study. In this study, using the combustion/chemical-engineering perfectly stirred reactor (PSR) mixing structure or 0D box for the model basis, as an alternative to the more commonly used global circulation models (GCMs), to define and determine the RT in the atmosphere and then using data from the IPCC and other sources for model validation and numerical determination, the data (1) support the validity of the PSR model application in this context and, (2) from the analysis, provide (quasi-equilibrium) RTs for CO2 of 5 years carrying C12 and 16 years carrying C14, with both values essentially in agreement with the IPCC short-term (4 year) value and, separately, in agreement with most other data sources, notably, a 1998 listing by Segalstad of 36 other published values, also in the range of 5−15 years. Additionally, the analytical results also then support the IPCC analysis and data on the longer “adjustment time” (100 years) governing the long-term rising “quasi-equilibrium” concentration of CO2 in the atmosphere. For principal verification of the adopted PSR model, the data source used was the outcome of the injection of excess 14CO2 into the atmosphere during the A-bomb tests in the 1950s/1960s, which generated an initial increase of approximately 1000% above the normal value and which then declined substantially exponentially with time, with τ = 16 years, in accordance with the (unsteady-state) prediction from and jointly providing validation for the PSR analysis. With the short (5−15 year) RT results shown to be in quasi-equilibrium, this then supports the (independently based) conclusion that the long-term (100 year) rising atmospheric CO2 concentration is not from anthropogenic sources but, in accordance with conclusions from other studies, is most likely the outcome of the rising atmospheric temperature, which is due to other natural factors. This further supports the conclusion that global warming is not anthropogenically driven as an outcome of combustion. The economic and political significance of that conclusion will be self-evident.
August 7th, 2009 at 10:19 am
Thank you. Very good indeed. I will be very interested to see eventual results from the CLOUD experiment at CERN, and how they fit in with this information.
http://public.web.cern.ch/Public/en/Research/CLOUD-en.html
August 28th, 2009 at 11:52 am
Isn’t the conclusion the same: Don’t add more carbon dioxide to the atmosphere?
September 1st, 2009 at 7:02 pm
@onearth:
August 28th, 2009 at 11:52 am
Isn’t the conclusion the same: Don’t add more carbon dioxide to the atmosphere?
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Actually, no. Plants grow much better in higher CO2 levels, and, of course, that means they produce more oxygen for us. I gather greenhouses typically pump in CO2 to about 1000ppm for optimum growth. Throughout much of history, CO2 levels were vastly higher than they currently are – in other words, all organisms evolved to cope with higher levels than present day.
Also, see this paper regarding the sun’s effects on the earth’s temperatures, and where the current length of solar cycle is likely heading us (its a .pdf file).
http://www.warwickhughes.com/agri/Solar_Arch_NY_Mar2_08.pdf
Climatology is still in its infancy – the science associated with it is still very much up in the air. There are many changes in the base understanding and assumptions that are implied in recent research.
Furthermore, its highly questionable whether we are even able to make any significant difference without doing drastic damage to our very lives, our standard of living, economy, etc. on a worldwide scale. For example, if we fully implement the cap and trade bill recently passed in the House here in the USA, and assume that the IPCC projections and assumptions are correct for the purposes of calculations, then apparently it will only reduce global temperatures by something like 0.2 degrees. The damage to our nation in terms of net job loss, reduced GDP, etc., would be huge – especially considering how shaky the economy is right now.
September 1st, 2009 at 7:09 pm
I should also have added that this very article basically says that the IPCC is drastically overestimating the CO2 effect to begin with, because of the false assumption of the duration of CO2 in the atmosphere. Which means that the calculated 0.2 degree reduction if cap and trade is fully implemented would also have been overestimated, and the effect of us reducing CO2 emissions would be far less.
You might also be interested in these:
Carlin Investigation Continues: Inhofe, Barrasso Send Letter to EPA On Possible Manipulation of Endangerment Finding [referring to the EPA 'finding' that CO2 is a pollutant that needs to be reduced/regulated] http://epw.senate.gov/public/index.cfm?FuseAction=PressRoom.PressReleases&ContentRecord_id=E7A1A451-802A-23AD-4350-FDB4A497DB37
Update: More Than 700 International Scientists Dissent Over Man-Made Global Warming Claims http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=10FE77B0-802A-23AD-4DF1-FC38ED4F85E3
http://www.petitionproject.org — see their research summary paper linked at that page thru one of the buttons at the bottom of the page. This is the 31,000+ American scientists who have signed a hardcopy petition that man produced CO2 is NOT a problem nor will it cause significant global warming.
October 31st, 2009 at 1:35 am
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January 2nd, 2010 at 3:14 am
You only tell 1/2 the story……what happens when the air starts to get saturated with CO2 and plants can’t absorb it all? Do those plants keep growing? Do Humans keep growing?
“Plants need CO2 and, therefore, will thrive under more concentrated atmospheric conditions. These plants will absorb the excess CO2, but there is a level where plants can no longer absorb the gas, and CO2 becomes toxic. Too much CO2, like too much fertilizer, stunts the growth rate of many plants. ”
And
“Humans are affected by too much CO2 in the air more quickly than by lack of O2. Higher levels of CO2 are toxic to humans, primarily due to oxygen deficiency”.
January 2nd, 2010 at 6:59 am
There’s not enough fossil-carbon fuels for atmospheric CO2 to get anywhere near toxic levels.
January 6th, 2010 at 2:52 am
Did you guys read the article? He is saying IPCC was radically wrong in their Summary for Policymakers. He is saying that the residence time of CO2 is only five years. Let’s do a little arithmetic here. 750 Gt carbon in the atmosphere, five year residence time, each year arond 150 Gt goes in and out due to vegetation/algae growing/rotting and the oceans absorbing/spewing back in. We are putting in a maximum of 8 Gt/year, we are a pimple on Mother Nature’s posterior, lost in the natural standard deviation. AGW is a masssive hoax, wake up and smell the coffee people! Professor Essenhigh for Leader…
January 6th, 2010 at 3:05 am
Thanks Michael. There’s a graphic of some published atmospheric CO2 residence times here:
http://c3headlines.typepad.com/.a/6a010536b58035970c0120a5e507c9970c-pi
I thought it might be good news if CO2 resides in the atmosphere for less time that the IPCC’s claimed 50 to 200 years.
January 6th, 2010 at 3:34 am
Magnificent. I am sending this to my Congressman even though I live in the bluest of blue states Illinois! For anyone willing to open up their minds this should put the entire question to rest.