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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just one little question, we are talking about c02, i am wondering since the human race is growing fast,nearly 7 billion of us, and we all breathe out c02, how much of that 280ppm is human waste.
Would less humans mean less co2?
John Finn (10:59:36) :
Whereas you appear prepared to believe any old rubbish as long as it supports your fervent wish that CO2 should have no effect. Well, suit yourself, but when you find that AGWers are able to ridicule sceptic arguments don’t start whining.
Problem is that the AGWers are providing plenty of ridicule, but most of the *refutation* is coming from the sceptical side.
Anything and everything is subject to being ridiculed, but ridicule isn’t refutation. If I said, “Guache sticks to sharks,” you can ridicule it all day long, but unless you refute it by showing that it *can’t* — because water-based paint dissolves in water — I’ll continue to support my statement.
Wren (22:38:40) :
A few decades ago doctors were wrong about what caused ulcers. Does that mean I shouldn’t trust my doctor?
Ever heard the phrase, “Get a second opinion”…?
If I’d blindly trusted a doctor forty years ago, I’d have a hook on the end of my left arm instead of a functioning hand.
mercurior (00:05:46) :
just one little question…Would less humans mean less co2?
An excellent question — unfortunately, the answer is, “That depends.”
In a static environment, the answer would probably be “Yes, a little” — but we live in a dynamic environment. CO2 levels were bobbling up and down before humans appeared, and they’ve continued to do so, pretty much independently of whatever contributions we’ve made.
This is really educative and useful to readers.
would it mean less number of human being will reduce co2 level cosiderably ? answer could be yes and no too.
the increasing level of co2 is a matter of worry for all of us and we all should not e and take care of it.
model is only a tool of approach,
global citizen need easy-to-implement plans to adapt with changing climate
Reed Coray (23:24:04) :
Reed is correct about this. Using the frequency form of Planck’s Law to find the radiated power involves the integral: ∫f3df/(ehf/kT – 1). Changing to the variable x = hf/kT brings the well-known T4 factor outside of the integral, and gives a new integral: ∫x3dx/(ex – 1). If the limits are not (0,∞), however, each limit will depend on T, as in x1 = hf1/kT, and x2 = hf2/kT, and thus the new integral will be a function of T, and not just a simple number. For example, if you consider only the range of longwave frequencies where hf is significantly less than kT, the power emitted in that range is proportional only to T, not T4.
/dr.bill
Sorry about the formatting in the previous note. It seems that we can’t use the full set of HTML tags (notably sub- and super-scripts). 🙁
/dr.bill
It looks as if Phil is happy to ignore any and all Refutations of his beliefs and states his “Facts” with such conviction he must be a Climate Scientist.
Re: dr.bill (Mar 9 02:40),
Reed is correct about this.
No, I think Phil is correct. cba explained it here. Kirchhoff’s Law applies over frequency intervals, and an albedo of 0.7 for SW coupled with IR emittance of 1 is quite possible, and indeed true. KL requires only that the IR absorbance also be 1.
Reed’s and your calculation only show that the Stefan-Boltzmann T^4 dependence would not then (exactly) apply. Phil didn’t say it would.
If I understand the above comments, it seems that there is broad agreement that the CO2 GHG effect is logarithmic and therefore gives fairly minor warming. The serious warming depends on a positive feedback loop involving increased atmospheric water vapour, its GHG effect, more warming, more water vapour, etc.
If this were true, initial warming for any reason, such as changes in the earth’s orbit, could trigger catastrophic warming due to water vapour. What about localised runaway warming where massive heat and water vapour is produced by a volcano? The earth would have been roasted to a crisp millions of years ago.
I don’t buy any of this. Water provides negative feedback. It is the climate’s thermostat. It is a GHG, but it also reduces incoming energy (as clouds) and through its phase changes and transportation throughout the atmosphere it gives sophisticated and complex control of heat. The climate scientists choose to ignore most of this because they don’t know how to model it. I don’t blame them for that, but I do blame them for the simplistic nonsense about runaway warming.
I find the constant reference to the 30 degree greenhouse effect very puzzling. Based on the Stefan-Boltzmann law, the Earth as a black body should be about 278 Degrees and not the often quoted 258 degrees. Most climate scientists ingore the fact that the Earth is a system involving oceans and the atmosphere and both are contributing to the socalled greenhouse effect. You cannot just say the earth without the atmosphere would be a certain temperature because you have no scientifically valid basis for such an assessment. The albedo factor often used refers only to the visible light albedo. More than half of the sun’s radiation is outside the visible range and exhibits a much lower albedo. Further, the visible albedo which has been measured is a variable and seems to be controlled somehow by solar activity. Throw in the fact that the solar constant is not infact constant and you can see that any analysis based on the 30 degree warming factor is spurious. There are far too many variables and far too little understanding of the processes involved.
It would be interesting to see an analysis of the entire system including the fact that solar heating is a three dimensional phenomenon with ocean heating occurring up to several hundred meters. In the tropics, that heat cannot move to the surface as the surface waters are always warmer. So the heat then moves toward the poles where the cooler waters are (iaw the second law of thermodynamics, the most often violated principle of physics by climate scientists). In the tropics you will find the so called greenhouse effect is only about 5 or 6 degrees. If the effect was atmospheric wouldn’t be nearly constant around the globe? I would like to see some discussion of these points if there is anyone out there with scientific answers.
Thanks
Nick Stokes (14:44:09) :
Re: Smokey (Mar 8 14:22),
Dr Kreutz took 64,000 separate CO2 readings at the Geissen weather station over two years.
Yes, he did. And they are extremely erratic (Fig 5). They vary up and down between about 310 ppm and 550 ppm. They don’t correlate with Beck’s global figure at all.
He even (Fig 8) shows one of his sites with a 100 ppm variation overnight.
The chemical analysis may have been accurate. But they are not measuring global CO2.
Evidence for which??????????????
Louis Hissink,
I greatly respect your opinion. So let’s throw out the Giessen data. In fact, let’s throw out all of Beck’s data reconstruction. What are we left with?
We are left with the presumption that the atmospheric CO2 concentration has been rock steady, at the same pre-industrial level for thousands of years. What does this mean?
It means that the LIA, and the MWP, the RWP, and other very significant natural climate changes were not influenced at all by CO2 levels, once again falsifying the repeatedly falsified CO2=CAGW conjecture.
Why and how CO2 logarithmic effect is modelled, people / history / plus a few plots,
all in a free pdf.
(http://www.)
globalwarmingskeptics.info/forums/thread-309.html
Oh, and how in 1999 it was shown beyond dispute by Richard S Courtney that the after the fact, invented, fudged, “coolings factors” used in GCMs were admitted by the modellers as false.
ie FRAUD.
All peer reviewed and published in 1999
– where were you all…
Looking at a Hocket Stick. Dooooh…
Why, were the false cooling factors needed in the models,
because the assumed warming mechanism was making too much heat…
For the layman reading this blog. Let me put my spin on the subject .
Lets say that I have a pool water. 50 meters by 50 meters. Over the center of the pool, I have a bunch of rocks weighing between 20 and 50 lbs. I’m going to drop the rocks in no particular order creating different highs and lows of waves reaching the edge of the pool. I also place a rubber ducky about 5 meters from the edge of the pool. As the wave the rocks the rubber ducky. The rubber ducky makes its own little wave. On paper or computer model that the little ducky wave is adding to the source wave in the center of the pool. It looks good on “paper” but they can’t physically measure the ducky wave at the center of the pool. So what happens when I stop dropping rocks. The water becomes calm and at the very end you can look at the rubber ducky and see the little tiny wave it created. The AGW people say “see, if we add more rubber ducks, we will create a tidal wave and the pool will explode.” But the fact remains, the water at the center of the pool is calm and the energy from the rubber ducky didn‘t add any energy to the source point of the wave created by the rock.
Larry Barnes (04:08:37) :
I find the constant reference to the 30 degree greenhouse effect very puzzling. Based on the Stefan-Boltzmann law, the Earth as a black body should be about 278 Degrees and not the often quoted 258 degrees.
Could you show the calculations for the 278 degrees.
I really enjoy Phil. Everything he says is usually right. Its like a puzzle that you have to look at really closely to figure out what the missing piece is.
Like radiative heat loss is the dominant heat loss route and the only heat loss route outer space, do the math, way bigger than convection. He’s right of course, the point being that convection causes HUGE changes to how much is radiated and from where and in terms of how much escapes and how much doesn’t.
Then there’s that whole thing about CO2 being the majority of the “permanantly radiatively active” gases in the atmosphere. No need to get into what the definition means because it is completely misleading as it has nothing to do with the issue. The issue is what gases are in the atmosphere that are radiatively active at any given time and what are their relative concentrations? Totaly different answer.
It is tactics like these, aimed at people to whom the answer is calculated to be slightly over their heads and raise doubt as a consequence that leads me to discount his answers even on topics where the discussion is well over my head. It is a tactic that I see used repeatedly by strong promoters of AGW and raises the same thought in my mind each time I see it.
If their science is sound, why must they resort to such tactics?
mercurior (00:05:46) :
just one little question, we are talking about c02, i am wondering since the human race is growing fast,nearly 7 billion of us, and we all breathe out c02, how much of that 280ppm is human waste.
Would less humans mean less co2?
Keep in mind that humans have replaced other species in vast numbers. That is part of being at the top of the food chain. So, while there are more humans, there are fewer bears, lions, tigers, gators, wolves, etc.
Even so, I suspect large mammal contributions to overall CO2 to be minuscule.
Nick Stokes (03:53:14) :
My note was about the temperature dependence, which can be substantially different than the T^4 behaviour, depending on which frequency slice you’re looking at. There’s no dispute about that, but people tend to forget it, just as they forget that not everything is a blackbody.
Emissivity, albedo, and all those things, are a can of worms. If you really need to know them for a particular problem, you have to measure them in situ and use them under those same conditions. This is what makes them an “engineering approximation”, because there is no way to find them from first principles. They vary not only with the properties of the object itself, but also with a host of other time-and-location-dependent factors. Trying to assign “single-values-for-all-time” to such things for something as temporally and spatially diverse as the Earth is simple nonsense.
/dr.bill
“” Larry Barnes (04:08:37) :
I find the constant reference to the 30 degree greenhouse effect very puzzling. Based on the Stefan-Boltzmann law, the Earth as a black body should be about 278 Degrees and not the often quoted 258 degrees. Most climate scientists ingore the fact that the Earth is a system involving oceans and the atmosphere and both are contributing to the socalled greenhouse effect. You cannot just say the earth without the atmosphere would be a certain temperature because you have no scientifically valid basis for such an assessment. The albedo factor often used refers only to the visible light albedo. More than half ….
“”
Usually, it’s Bond albedo which is the whole enchilada – uv – IR, not that it is something well measured over the long run. It’s about 0.3 with that breaking down to 0.22 for clouds & atmosphere and 0.08 for Earth (being that oceans and h2o liquid have very low albedo for light incident at high angles relative to the horizon).
What is being done is the averaged power per surface area of the Earth is being corrected for loss due to albedo reflection, which amounts to about 1/3 of the incoming power. Certainly, with no atmosphere or ghgs in an atmosphere, there’d be no clouds and no liquid water so the albedo would probably be around 0.15 (like Mars and Moon). One can either go with the current albedo for a direct comparison between things or one can inject more uncertainty and try comparing apples and oranges with many varying parameters and no way to grasp the significance of anything.
Considering the effect of the clouds on albedo (and also upon the ‘blocking’ or limiting of the outbound lwr), they are a substantial determiner of our temperature – and undoubtedly primary in a negative feedback control system regulating our planet’s temperature (somewhat along the line of Lindzen’s Iris effect). However, in order to understand and explore what happens, one must isolate the various factors to see how they function. Toss them together in a model and you’ve gcm garbage, incapable of being understood or verified or falsified.
Nick,
I guess I don’t understand the depth of your question about how h2o gets somewhere or why you think it’s related to a lapse rate or temperature difference. h2o is a lighter molecule which tends to provide a lower density – which has buoyancy. It also absorbs IR so it’s going to heat up from the IR – which isn’t in the physical meteorology 101 text. Hot gas expands – reducing density – increasing buoyancy. The lapse rate doesn’t matter, it’s the T differential between moist and dry gas and the overall density difference. That’s undoubtedly driving most of the vertical mixing and no one objects (that I’ve seen) to the notion that the atmosphere is well mixed. All I can see is that either you’re not understanding something mentioned above, or you are hung up on something else perhaps more complex but also perhaps less relevant or that maybe you should introduce.
@Rhoda R (14:41:21) :
Toyotawhizguy: “Only the water vapor aspect is well understood, and is widely agreed upon as being positive.”
But is this true? I thought that part of the water vapor aspect was more water vapor available to develop cloud cover which would tend to be negative.
——————-
Yes, clouds are formed from water vapor, but the feedbacks from clouds are very different than for water vapor, thus Climatologists treat clouds as a completely separate entity from water vapor as regards feedbacks. I agree with you about the negative effect, and think it’s most likely that the net effect of clouds is negative, but what do I know?
Water vapor is mostly transparent to sunlight in the visible range, and does absorb a bit of sunlight in the shorter IR bands. But water vapor is the prevalent greenhouse gas, as it absorbs large amounts of long wave IR radiation radiated by the earth. If CO2 forcing produces more water vapor, that aspect (ignoring clouds) is a positive feedback (But how much?).
See this graph for the Solar Radiation Spectrum that shows water vapor’s effect on incoming sunlight.
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
This graph shows how greenhouse gases absorb earth’s longwave radiation (Notice the extent that the absorption bands for water vapor overlaps with the absorption bands for CO2! Redundancy in the greenhouse effect!)
http://en.wikipedia.org/wiki/File:Atmospheric_Transmission.png
“A picture is worth a thousand words and a graph is worth a thousand pictures.”
Louis Hissink (04:31:44) :
Nick Stokes (14:44:09) :
Re: Smokey (Mar 8 14:22),
Dr Kreutz took 64,000 separate CO2 readings at the Geissen weather station over two years.
Yes, he did. And they are extremely erratic (Fig 5). They vary up and down between about 310 ppm and 550 ppm. They don’t correlate with Beck’s global figure at all>>
Yes of course, why didn’t I see it before? Tracking diurnal changes in CO2 to understand daily cycle effect of vegetation completely invalidates the guy’s ability to derive an annual trend from the same data.
Hey CRU, GISSS, all you guys. Have any of you got daily temperature swings of say 10 degrees in your data? Really? You do? Well, I am sad to tell you that this means you are incompetent, your data is invalid, we’re measuring annual trends in tenths of degrees here and you guys have botched it. Delete your data, pick up your last pay check and turn out the lights on your way out.
@Derek (05:01:54) :
Why and how CO2 logarithmic effect is modelled, people / history / plus a few plots,
all in a free pdf.
(http://www.)
globalwarmingskeptics.info/forums/thread-309.html
————
Link doesn’t work. Try this:
http://www.globalwarmingskeptics.info/forums/thread-309.html