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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IMHO it all comes down to feedbacks. A doubling of CO2, by itself, would cause warming of about 1C. The IPCC predicts a much greater increase of up to 6C based on climate models. But all of their climate models assume there are positive feedbacks which amplify the effect of the CO2. Professor Richard Lindzen in his paper “Deconstructing Global Warming” shows that the overall feedback is in fact negative. http://www.globalwarming.org/wp-content/uploads/2009/10/lindzen-talk-pdf.pdf
That paper is based on measurement of radiant energy leaving the earth, not on modeling assumptions.
Positive feedbacks imply an unstable climate that would be prone to going into a runaway effect. A negative feedback implies that the earth has a natural regulating system which tends to stabilize temperature.
Ken Roberts (07:41:04) :
“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…”
You forgot the fact that Mauna Loa is an ACTIVE volcano emitting CO2 so like the temperature measurements it has to be “adjusted”
http://sci.tech-archive.net/Archive/sci.electronics.design/2009-02/msg00386.html
Hey everybody!, climate changers found another scaring menace:
http://news.yahoo.com/s/mcclatchy/20100307/sc_mcclatchy/3444187
They are looking for a way out, however this too is a lie as PDO being negative (lower sea temperatures) increases oxygen solubility in sea water.
Another Ban kee moon science-global government marketing.
Man is not creating C02. He is releasing it from storage by the burning of hydrocarbons made by the biosphere and stored by geology. There’s a big difference between the two.
This post is misguided on several levels. First, it assumes that the effect of CO2 is saturated over the whole frequency spectrum, which it is not. Some parts of the IR spectrum are indeed saturated, and CO2 increase won’t have any effect. But in other regions of the spectrum, and particularly at the poles, the edges of the CO2 bands are anything but saturated.
If you think of the atmosphere as a blanket with holes in it, you don’t get much improvement in the blanket by stretching a thin film over the intact part, but you do improve by covering the holes.
Second, it’s simply silly to say that the earth came close to catastrophe by going below the threshold for plant growth. What pulls CO2 out of the atmosphere is largely plant growth. It’s self limiting; as CO2 levels drop, plants grow less, and that limits further decrease in CO2.
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 ?>>
Try
http://www.john-daly.com/artifact.htm
Simulated earth atmosphere with 2.6% water vapor and two different levels of CO2 (one double the other) and measured absorption of LW being transmitted through it. Concluded IPCC estimates were high by 80X. However, my assumption is that this was done at room temp. Other temperature ranges and other water vapor concentrations would give different results. Earth is inconveniently round, spinning, and has the atmosphere on the outside as opposed to a cylinder with atmosphere on the inside.
John Finn…your application of “appeal to authority” is humorous, entirely fallacious from a logical pov, but definitely humorous.
It is feeblemindling groping in the dark, trying to guess phantoms by empty discourse, if temperatures will scorch us or not, and what causes what is it what we call it temperature.
J.C.Maxwell put it this way:
“…when, however, there is a general transference of particles in one direction, they must pass from one molecule to another, and, in doing so, may experience resistance, so as to waste electrical energy and generate heat”
“On physical lines of force” , by J.C.Maxwell.
In reply to Mike,
Yes, AGW skeptics say that the climate is too complex for all of the models to properly account for all of the variables and how they interact. That is a true statement.
However, it is still possible to show with some very simple mathematical exercises that their assumptions are probably outlandish.
The two statements are not incompatible with each other.
Hi could someone tell me where I can find what the total Infra red energy coming to the Earth from outer space, which is of the frequency which can be absorbed or radiated back to earth or reflected back to space by co2?
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”.
Now that is funny…and sad. Difference between an engineer who has to make something work and an academic that merely has to satisfy his “customers” desire for results in a certain form. What if we added a little feedback into the funding cycle? Observable predictions result in more money, missed or unexplained observations result in less money? Would that have runaway negative feedback?
Larry – Interesting comment. I’ve always thought there was something strange about things were framed in terms of forcings, feedbacks, positives, negatives, fasts and slows. Perhaps someone was trying to avoid the simpler but peculiar sounding formulation…. warming is going to cause warming. What I’d like to say is that warming causes more humidity and more humidity will cause more frequent rains and more rain presupposes more clouds and even the IPCC admits that the effects of clouds on climate are poorly understood. Ergo, dire predictions are less than plausible and certainly uncertain.
Larry,
You are correct. A system which had a never-ending positive feedback loop would essentially self-destruct. Most sane people realize that the climate of the earth is not such a system. It is known that the warming effect of CO2 is logarithmic and not terribly significant, and it is now postulated that water-vapor feedback is actually negative rather than positive, so the climate seems to have a thermostat, so to speak.
Mike M (06:46:15) :
“As most plants receive more CO2 than the present day concentration they grow faster and fatter. In order to do that they must be absorbing solar radiation and converting it into potential chemical energy, (fats and sugars, etc.), at a faster rate. Such conversion by photosynthesis could be represented as ‘lost heat’ in the earth radiation budget in that radiation that arrives at the surface then ‘disappears’ from the equation.”
Yes, photosynthesis is strongly endothermic and increasing concentration of CO2 increases photosynthesis, so more cooling. Transpiration is important (latent heat of evaporation) but decreases somewhat with increasing CO2 as stomata close up. The plant canopy couples its cooling to the surrounding air by conduction, so to all air molecules, not just the tiny CO2 component.
Everyone knows that it’s cooler on a grass lawn than a concrete or asphalt yard. Some buildings deliberately grow grass on their roofs for their cooling effect.
Of course, all this endotherm becomes exotherm when the vegetation is burned and it reverts again to CO2 and water.
If people want carbon capture and storage, with cooling to boot, they could simply plant fast-growing trees, cut them down after 30 years and store the remains (including as the structure in permanent buildings). Much simpler than trying to do it on a coal-fired power plant.
David, To me an illuminating additional graph would show the theoretical cumulative radiative forcing of H2O and CO2 based on the assumption that incremental CO2 forces additional atmospheric H2O ie a stacked version of your last graph above (but ignoring other H2O feedback effects such as cloud effects and latent heat of evaporation etc) and ranging from 20 to 400ppm CO2 and beyond. I assume the forcing effects of CO2 and H2O are individually logarithmic with the H2O part being larger. Such a graph would show the effective baseline around which the other feedbacks are hypothesised to force reality. Of course my request assumes we know the pre-industrial level of H2O in the atmosphere and it’s relationship to temperature.
Isn’t it interesting?
We have to have HUNDREDS of temperature surface stations all over the world (whether they are accurate or not is another story)
We seem to rely on TWO tiny samples of trees – the famous bristlecones and the Yamal set, from two small geographic areas
We have ONE definitive measure of CO2 from Mauna Loa – even though atmospheric CO2 doesn’t seem to be evenly distributed around the world.
What’s the rationale for the various sample (or sampling) sizes? Am I missing something?
rob (04:00:46) :
… Over the past 140 years the British weather observatory situated in the Himalayas revealed a temperature drop of .4 degrees.
Think about it. This is the data you can trust. When a meteorological station is located far from urban environment and volcanic activity, when people recording the measurements are not financially interested in altering them, and when they don’t pick the lowest temperature dip as a starting point for comparison, suddenly there is no “global warming” and never was.
For this reason, and for many other equally important reasons, the United Nations should be boycotted and abolished. It is a criminal organization that causes enormous harm to freedom, culture, and civilization.
it was established before AGW ideology that c02 bandwidths are fixed at between 7 and 8% of outgoing atmospheric energy. Outgoing atmospheric energy is anything from 1-5% of the radiation budget (mainly from soils) that makes itself available to c02. Measured as temperature c02 capture is 0.15C, certainly not 3C.
only the stefan boltzmann equation could increase this 8% budget artifically to an absurdly higher figure to give 3-5C in the near future (the basis on which the calculation was made due to anthropogenic c02 emissions)
in fact there are many poorly applied equations used to contrive and exagerrate the greenhouse effect in order to increase the alarm and produce a hypothetical future 3-5C increase based on anthropogenic emissions. true,, deserts could give off more radiation- 10%, but matter at 15C, which is quite cool, thermalises so as not to radiate beyond 1% of its energy, besides which at those temperatures, IR radiation bypasses c02 – especially desert regions
Shade (08:15:35)
The temperature difference is explained by air pressure and the ideal gas law in a closed system. The atmosphere isn’t a closed system – The experiment would have to be 350ppm in a vessel and 450ppm in a larger vessel to create the same pressure. Then the experiment ( as tried by Anstrom) would reveal fairly objective results. The external heat source would have to correspond to earth temperatures between -40C and 45C
Ken Roberts (07:41:04) :
“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?”
Mauna Loa is the world’s largest volcano, and a very active one. Ever heard of how many gigatons of CO2 volcanoes put out?
Mauna Loa used to have pineapple plantations on its slopes near the laboratory, but these have dwindled away since the 1950s. Anyone know that pineapple plants, using the unusual CAM photosynthesis pathway, are among the world’s most efficient sequesterers of atmospheric CO2? The increase in ambient CO2 when removing pineapple plantations is well established.
Mauna Loa must be one of the worst places on earth to establish a benchmark for CO2 measurements. Unless you had a particular agenda, of course.
Funny that.
The very premise of this article that 30C increase in surface temperature is explained by greenhous effect is wrong. This difference is due to convection. It is the difference between surface temperature (+14C) and the temperature at lower boundary of stratosphere (-18C), since there is no convection above this altitude. But atmospheric convection is adiabatic: the same body of air ascending to, say, 10 km, will expand due pressure drop and so get cooler without loss of its heat content. This adiabatic cooling has nothing to do with trapping of infrared radiation, this is simply laws of gas expansion. What the Wood’s experiment really shown is that greenhouse effect does not operate in real greenhouses, the only heating is due to suppressing of convection. Does it operate in real atmosphere? Probably, yes, but trapping of heat will only enhance convection and so enhance convective cooling. No real experiment with real atmosphere is possible, but some observations indicate that the main heat-trapping gas is water vapour: day-to-night temperature difference is much higher in deserts, where air humidity is near zero, than in wet regions. During night convection is weak or absent, and most cooling is radiation cooling, and it seems, the only difference is water vapour content. CO2 does not enter into this effect, and its contribution is not known and can be immesurably small.
Henry Pool (07:59:34) :
It absorbs radiation at 13.7-16.3 microns with a peak of 15 microns – yet radiation on average leaves earth at 10 microns, which equates with 15C, or 288K. 15 microns equates with subzero temperatures that can be found at the poles – so heat capture of c02 in the atmosphere is a rather rare event, and is fixed at around 6-8% of atmospheric thermal energy, achieved by the 1st 100ppm where its absorbtion window closes – well outside of normal temperatures. Its true that a c02 molecule’s stretching mode would allow it to transfer energy to other atmospheric molecules, such as the ghg water vapour, but this requires so much energy that it doesn’t occur even at 300K, with the c02 absorbtion bands, and there’s some 3,000 other mlecules apart from c02 in a given volume of air, making collisions between thermally excited c02 molecules very unlikely. Molecules of like kind are more efficient at transferring energy to one another. In the absence of such, thermal degradation takes place very quickly. (a billionth of a second), so vibrationally excited c02 thermalises very quickly with oxygen and nitrogen
Ira (07:58:20) Thanks, Ira, that’s an excellent explanation of how this works. That, and the complete disconnect between historical CO2 and temperature (http://ff.org/centers/csspp/library/co2weekly/2005-08-18/dioxide.htm ) make it very difficult for me to believe in AGW.
also:
Richard111 (04:42:57) :
“As a non-scientist, can anyone please explain why there is no convective heating
of the atmosphere? Are thermals due entirely to CO2 in the deserts?”
Richard, I fly small airplanes in the desert, and CO2 has nothing to do with thermals. You get thermals that make you tighten your seat belts because there are few clouds. The sun differentailly heats the ground depending on local albedo. e.g. black highways are hotter than vegetation. This sets up convective cells. Air rises over the hot spots on the ground and settles over the cooler ground spots. Makes bumpy air.
In places like Florida, where there is a lot of humidity, clouds form where the updrafts take the water up to the altitude at which the water vapor turns to liquid droplets.
Sorry about the OT digression.
And I like this paper, which says that CO2 concentrations have been as high as 480ppm in the 1940s. Figures, derived through chemical gas analysis.
http://www.friendsofscience.org/assets/files/documents/CO2%20Gas%20Analysis-Ernst-Georg%20Beck.pdf
Any problems with this paper too?
.
One problem with these simple experiments is the climate system is not simple at all.