Guest post by David Archibald
The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere, so instead of the average surface temperature being -15° C, it is 15° C. Carbon dioxide contributes 10% of the effect so that is 3° C. The pre-industrial level of carbon dioxide in the atmosphere was 280 ppm. So roughly, if the heating effect was a linear relationship, each 100 ppm contributes 1° C. With the atmospheric concentration rising by 2 ppm annually, it would go up by 100 ppm every 50 years and we would all fry as per the IPCC predictions.
But the relationship isn’t linear, it is logarithmic. In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic heating effect of carbon dioxide relative to atmospheric concentration:
And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
I recast Willis’ first graph as a bar chart to make the concept easier to understand to the layman:
Lo and behold, the first 20 ppm accounts for over half of the heating effect to the pre-industrial level of 280 ppm, by which time carbon dioxide is tuckered out as a greenhouse gas. One thing to bear in mind is that the atmospheric concentration of CO2 got down to 180 ppm during the glacial periods of the ice age the Earth is currently in (the Holocene is an interglacial in the ice age that started three million years ago).
Plant growth shuts down at 150 ppm, so the Earth was within 30 ppm of disaster. Terrestrial life came close to being wiped out by a lack of CO2 in the atmosphere. If plants were doing climate science instead of us humans, they would have a different opinion about what is a dangerous carbon dioxide level.
Some of the IPCC climate models predict that temperature will rise up to 6° C as a consequence of the doubling of the pre-industrial level of 280 ppm. So let’s add that to the graph above and see what it looks like:
The IPCC models water vapour-driven positive feedback as starting from the pre-industrial level. Somehow the carbon dioxide below the pre-industrial level does not cause this water vapour-driven positive feedback. If their water vapour feedback is a linear relationship with carbon dioxide, then we should have seen over 2° C of warming by now. We are told that the Earth warmed by 0.7° C over the 20th Century. Where I live – Perth, Western Australia – missed out on a lot of that warming.
Nothing happened up to the Great Pacific Climate Shift of 1976, which gave us a 0.4° warming, and it has been flat for the last four decades.
Let’s see what the IPCC model warming looks like when it is plotted as a cumulative bar graph:
The natural heating effect of carbon dioxide is the blue bars and the IPCC projected anthropogenic effect is the red bars. Each 20 ppm increment above 280 ppm provides about 0.03° C of naturally occurring warming and 0.43° C of anthropogenic warming. That is a multiplier effect of over thirteen times. This is the leap of faith required to believe in global warming.
The whole AGW belief system is based upon positive water vapour feedback starting from the pre-industrial level of 280 ppm and not before. To paraphrase George Orwell, anthropogenic carbon dioxide molecules are more equal than the naturally occurring ones. Much, much more equal.
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Has anyone taken a chalk in his/her hands?. Well, you know it comes from the trillions of lime (calcium carbonate, chalck) deposits all over the earth. Wanna know fossil CO2? just see those inmense deposits: They TELL YOU how much CO2 there was in the past. See?. Well, all the rest is but the expression of a dying subculture, of naive ideologies, a product of too much hemp in the 1960’s. All those “philosophies” have taken you to the state of affairs that you msm qualifies as an inminent, and yours only to enjoy,”armageddon”.
As I understand the process at the primary sampling station for CO2 at Mauna Loa, a sampling tube is purged with inert gas and then a sample of air is drawn.
This sample is measured spectrographically and the daily results are added; has anyone ever established that the purging is fool-proof?
Has any study ever investigated the accuracy and reliability of the sampling process?
This graph is the grail — the foundation itself.
I would hate to learn that it gets dirty like my rain gauge.
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Richard Telford (04:39:45) :
The natural CO2 forcing is shown without any feedbacks, whereas the anthropogenic forcing is shown with feedbacks. This is misleading. Nobody would argue that the natural changes in CO2 are not magnified by feedbacks (try to explain the glaciations without feedbacks) One can argue about the magnitude of the feedbacks.
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Ice-albedo feedback is the major feedback during glacial transitions. This feedback is having little affect now because the remaining glacial ice @ur momisugly Greenland & Antarctica is at such high latitudes that relatively little sunlight is reflected (and hence our relatively stable temps during interglacials). Only when cold periods occur often enough and/or snowfall increases that snowcover survives much of the summer at lower latitudes will the ice-albedo affect become significant. No changes in CO2 are required — the CO2 changes during glacial transitions are the result of ocean in/outgassing from temp changes, not the other way around.
Do not be deceived by professionals from the European
narrative tales.
Pamela Gray (06:31:46) :
“Without decreasing LWR, the AGW theory and the models are proven false.”
The average LWR has not been decreasing, and there seems to be little correlation between outgoing LWR and the troposphere temperature: click
Some have decried why conventional media outlets don’t pick up on stories like this. Regardless of the merits of the article, the fact is that a good portion of the journalists and reporters get befuddled and have their eyes glaze over at the word “feedback” much less “logarithmic.” In other words, they don’t know how to write up their stories because they forgot all that “stuff” from High School and they don’t think anyone will read it.
Excellent article but I still have problem with the base methodology of deriving from a mixed gas even the reduced level of GWG attributed to 0.002% increments of the composite mixture.
To call this an empirical derivation is ‘I think’ misleading. There may not be supercomputers involved but there are still a lot of assumptions of understanding … you could say derivations based on a ‘model’.
My preference is to simply strike this term in the equation to 0 (or insignificant) given we consider the ‘base case’ (0 on ‘y axis’) the suffocation of plant life and not even consider what happens below ~200 ppm (0.02%).
Thanks for the like Mari.
Smokey,
Theoretically it could depending on the feedback factor. But if we would have that strong feedbackfactor, the earth would already have ran away, but it didn’t, so it isn’t.
Sorry, thanks for the LINK Mari.
hhtp/www.scribd.com/doc/28018819/Greenhouse-Niels-Bohr
True, CO2 increases should have a roughly logarithmic effect, but water vapor feedback should ALSO have a logarithmic effect. I think that’s one item missing in their logic when the Catastrophic Anthropogenic Global Warmers present their apocalyptic scenarios.
About 4.6 billion years ago, the sun was roughly 70% as luminous as it is now. Using a linear extrapolation of luminosity increase, the sun must have been only 75% as luminous as it is now at 3.8 billion years ago, yet by that time the world had oceans and life, and a mostly nitrogen atmosphere, as it does now. OBVIOUSLY the feedbacks must be mostly negative, probably due to clouds, else the world’s oceans would have boiled away billions of years ago, else the earth would have been a frozen, lifeless slab 3.8 billion years ago.
Here is a short, animated PowerPoint Show with audio to illustrate why the “greenhouse” effect of CO2 is roughly logarithmic. The 15 micron band of radiation from the Earth reached 100% absorption when CO2 rose to nearly 300 ppmv prior to the industrial age. That is why the roughly 100 ppmv added by recent human activities has had a minimal effect. Even if CO2 goes up another 100 ppmv, to 500 ppmv over the next 50 years or so, the effect will be minimal. This is compatible with David Archibald’s charts.
A longer version of the above, showing why human-caused “global Warming” is not a crisis and why water vapor most likely has a net negative feedback, is available here.
Henry @ur momisugly David Archibald
Sorry, but I am not sure where this information comes from that
“Carbon dioxide contributes 10% of the effect ”
first of all, how do we know for sure that CO2 is a greenhouse gas?
The trick they used (to convince us) is to put a light bulb on a vessel with 100% CO2.
But that is not the right kind of testing.
You must look at the spectral data. Then you will notice that CO2 has absorption in the 14-15 um range causing some warming (by re-radiating earthshine) but it also has a number of absorptions in the 0-5 um range causing cooling (by re-radiating sunshine). So how much cooling and how much warming is caused by the CO2? How was the experiment done to determine this and where are the test results?
Hans Erren (05:43:53) :
David, as a skeptic who is well versed in the logarithmic nature of CO2 forcing, I dont have a clue which message you are trying to give here. The co2 range of interest is 100 to 1500 ppm, and already Arrhenius confirmed in 1906 that this leads to a 1.2 degree temperature rise for every doubling. The only debate is now about feedbacks: Is miskolczi right that tau is a constant (which means co2 is compensated by less water vapour) or is IPCC richt that that the feedback is positive. This posting is really not helping in this debate.
Yes, IPCC knows that carbon dioxide has a logarithmic effect (look for Myhre simplified expression) http://www.grida.no/climate/ipcc_tar/wg1/222.htm
Hans
Thanks for your contribution. I fear it will do little good, though. David’s argument is similar to many that were being put forward on ‘maverick’ blogs when I first starting looking into AGW several years ago. Eventually you learn to filter out this sort of rubbish.
Of course we know that the CO2 effect is logarithmic. There is no-one on either side of the debate who doesn’t acknowledge this. I, like you, am not sure what David’s motivation for this post is (another book perhaps?)
Anyone who thinks that the effect of COO2 in the atmospehere in insignificant should take a look at emission spectra graphs. Steve McIntyre looked into the issue a couple of years ago. See
http://climateaudit.org/2008/01/08/sir-john-houghton-on-the-enhanced-greenhouse-effect/
In this post, he included a graph which showed a comarison of theoretical and observed radiances for a clear atmosphete at 15N; 215W (see Fig 3). Steve makes the following comment
John Eggert (06:07:51) :
“…. If Anthony is interested, I can send him a paper I’ve written that clearly shows the method for obtaining these including sample calcs, etc. that make creating the graphs relatively trivial.”
I do not know about Anthony, but anything that helps clarify the science for the rest of us is much appreciated.
The temperature sensitivity of CO2 is clearly not logarithmic over the entire range. The logarithmic relationship appears to range from about 40ppm to about 200ppm. After that it looks more like a 1/x type relationship. Maybe the whole curve is closer to 1/x. Has anyone tried doing such a plot?
A logarithmic curve is a 1/x curve (roughly) over narrow ranges.
Do they still teach algebra in high school?
Would it not be relatively simple to create practical experiments to show the effect of different levels of greenhouse gasses – or has this already been tried and, if so, what were the results?
The BBC made a simplistic experiment to “prove” that higher C02 “caused warming” during Copenhagen by heating 2 plasic bottles of “atmosphere”, one with more C02 than the other, with two electric light bulbs. There was no measurement of the amount of C02 being used or the relative heat of the 2 bulbs so the experiment imho was useless. The temparature of both bottles shot up with the increase in the one with the higher C02 being slightly ahead of the other. My conclusion was that the main reason for the increase in heat was the light bulb (“sun”?), not the C02 but the audience appeared to be convinced.
If no experiments have been performed, would it be possible to create containers with exactly the same atmospheres in them but then add extra levels of ppm of C02 and/or other trace gasses to certain containers and then observe what happened naturally to the temperatures of each container over time ?
A better link than above and a nice short description of the origins of this discussion … Arrhenius vs Bohr.
http://my.telegraph.co.uk/reasonmclucus/blog/2009/02/07/greenhouse_theory_disproved_a_century_ago
I haven’t seen anything that would keep me from ignoring this whole ‘effect’ and striking CO2 in the equation to zero.
The enhanced greenhouse effect appears to be a misnomer, because the positive feedbacks do not appear to be caused by the c02, but caused by the rise in temperature caused by the co2 (or am I missing something?). This would suggest that any temperature increase causes an increased temperature (i.e. the sun warms up slightly causing water vapour to increse and icebergs to recede etc. etc.)
Systems that exhibit this phenomena in electronics are described as having hysteresis (they tend to lock at their maxima or minima, and are used to remove noise when moving from an analog to a digital world). It seems bizarre for scientists to be characterizing a natural system to be exhibiting more positive feedback than negative – at least without defining when the negative feedback will kick in.
Any computer model with a little bit of excess positive feedback is going to predict whatever it is modelling is going to hell in a handcart over sufficient iterations. These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.
John Finn (08:00:45) The large notch or “funnel” in the spectrum is due to “high cold” emissions from tropopause CO2 in the main CO2 band. CO2 emissions (from the perspective of someone in space) are the coldest.
And how is this differentiated from a gas mixture with no CO2, in determining this effect? How do you remove all the other explanations for the observed behaviour of a mixed gas? I have yet to see a ‘controlled experiment’ that cleanly shows this exists and on the surface the very idea of this massive energy foci appears implausible. Something else is going on and only the ‘political focus’ on CO2 becomes self evident the more you dig down into this subject. That is a very interesting (old) story in itself.
Why is there an assumption that CO2 dispersion, inbound solar energy, and outbound LWR – are spatially uniform?
Mike M (06:46:15) :
“As most plants receive more CO2 than the present day concentration they grow faster and fatter….
I wonder then, given CO2’s logarithmic, ‘diminishing return’, nature, could the above negative feedback of photosynthetic radiation loss, at some higher PPM concentration, utltimately overtake CO2’s GHG effect on an incremental basis?”
I love it. A provable negative feedback effect from increasing CO2. Mann-made CO2 causes GLOBAL COOLING. I guess we will have to keep this one under raps or the political types will use it when the climate turns cooler for the next 30 yrs.
@ScientistForTruth:
“No – that can’t be right: any cumulative effect must go through the origin: there can be no good reason why positive feedback would kick in at 280ppm.”
Actually, there can. Around that level, most of the moisture in the atmosphere today would have precipitated out as snow due to the cold, i.e. what happens when you are in a death spiral headed toward an Ice Age, the poles, where most of the warming happens, would be bone dry in the atmosphere, any atmospheric moisture would come from polar ice evaporating due to low vapor pressure. What we need to see is a similar curve for the forcing of H2O (according to whatever law it behaves by, linear, log, geometric, etc) along with what temperature to expect each given level of atmospheric H2O.
Some say H2O is negative forcing in its sensitivity, others say positive. If it were truly, solidly negative, then a H2O rise will always be the trigger of a new ice age, but ice cores don’t reflect that, instead you see slow CO2 drawdowns causing gradual cooling over thousands of years (excepting freshwater injection events like LD, but those only happen at the end of a glaciation, not the start). If it were truly positive, then a H2O rise like that were seeing would always be the trigger of a catastrophic flooding of the globe, but we don’t see that either, the only catastrophic floodings happen at the end of glaciations (draining Agaziz, filling the Med, the Red, and the Black seas..) .
Because atmospheric water vapor both cools during the day, and reduces cooling at night, its more fair to say that increased water vapor is going to increase volatility in climate in both directions, which I believe is what most middle of the road climate folk believe anyways. The big question in dispute is how sensitive H2O is to CO2 levels.
Is anyone out there thinking?
CO2 is a gas found in the atmosphere. As is true of many molecules, CO2 responds to certain incoming radiation (photons) by jumping to an excited state. I am citing the obvious here. What then? Does the CO2 remain excited forever? No. The excited state decays back to an unexcited state, releasing the quantum of energy (this time without regard to direction).
The absorbed energy CANNOT remain in the atmosphere, in excited CO2 molecules. In the outgoing energy from earth, only a certain portion is found in energy levels to which CO2 responds. It is kind of like a food fight. If one CO2 molecule gets the photon, another one does not. So distributing the energy among more CO2 molecules means (inevitably) that fewer of them (proportionally) will be excited.
This non-equation view should suffice to explain why there cannot be a linear relation between CO2 concentration and infrared absorption and re-radiation.
Looked at from a statistical perspective, such a relation is tailor-made for a logarithmic relation.
And that is what the data shows.
That first 20 PPM of CO2 ALL get excited.
But saturation sets in. In fact I would suggest exploring the logistic curve as an even better model.
Oh, well. I am not being paid by any oil companies, so I have nothing to prove.
Hans Erren (07:00:00) :
Perhaps ou need to get away from the poison angle and take the life giving approach: that trace of CO2 supports all life on the planet without it (and water) the planet would be be lifeless.
I just like this perspective better.
Well………it can be green house effect can increase exponentially in later days……….Am worried and everyone