CO2 reverse logarithmic greenhouse effect

[glenncz]

Hi Q.
I keep coming across my pals stating that increasing CO2 will only have a mild effect on temperature, because it has a reverse logarithmic GHG effect. The first 20 ppm have a big effect, then less so to 100 ppm and then by the time we get to 380, doubling it's concentration will have little effect.
I found that greenhouse plastic has a similar effect.
http://www.nofreewind.com/2009/12/dimin ... c-co2.html

some other pal told me that even the IPCC agrees that: the reverse logarithmic effect from CO2 "settled science".

and I found these people who seem to agree... according to Stefan Boltzmann law and Idso paper and U of Chicago MODTHRAN and Beer-Lambert law?
what's the workaround?
whats up with that?

[questioner]

Hi Q.
I keep coming across my pals stating that increasing CO2 will only have a mild effect on temperature, because it has a reverse logarithmic GHG effect. The first 20 ppm have a big effect, then less so to 100 ppm and then by the time we get to 380, doubling it's concentration will have little effect.
I found that greenhouse plastic has a similar effect.
http://www.nofreewind.com/2009/12/dimin ... c-co2.html

some other pal told me that even the IPCC agrees that: the reverse logarithmic effect from CO2 "settled science".

and I found these people who seem to agree... according to Stefan Boltzmann law and Idso paper and U of Chicago MODTHRAN and Beer-Lambert law?
what's the workaround?
whats up with that?

No workaround needed. The logarithmic effect is there, but the coefficients are large enough that the increase in temperature is about 3C. Remember that the total effect of all of the GHG's, including positive feedback is about 33C.

http://en.wikipedia.org/wiki/Greenhouse_gas

Greenhouse gases are gases in an atmosphere that absorb and emit radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect.[1] The main greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. In our solar system, the atmospheres of Venus, Mars and Titan also contain gases that cause greenhouse effects. Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would be on average about 33 °C (59 °F) colder than at present.

So it is not surprising to get an effect of about 3C or even more from an additional 2X increase in concentration.

[glenncz]

I am not saying this is authoritative, because I know there are many views, esp when the science is not settled.
http://www.davidarchibald.info/papers/S ... 202008.pdf

Starting on page 22 he talks about the decreasing logarithmic effect of CO2 on the greenhouse effect. Is this accepted by all scientists as pure science? He comes up with the same 3 degrees you mentioned, but we are already there. Do you know what chapter IPCC report discusses this?

"The effect of carbon dioxide on temperature is logarithmic and thus climate sensitivity decreases with increasing concentration. The first 20 ppm of carbon dioxide has a greater temperature effect than the next 400 ppm. The rate of annual increase in atmospheric carbon dioxide over the last 30 years has averaged 1.7 ppm. From the current level of 380 ppm, it is projected to rise to 420 ppm by 2030.
The projected 40 ppm increase reduces emission from the stratosphere to space from 279.6 watts/m2 to 279.2 watts/m2. Using the temperature response demonstrated by Idso (1998) of 0.1°C per watt/m2, this difference of 0.4 watts/m2 equates to an increase in atmospheric temperature of 0.04°C.
Increasing the carbon dioxide content by a further 200 ppm to 620 ppm, projected by 2150, results in a further 0.16°C increase in atmospheric temperature."

[glenncz]

The best answer I found was right here.
http://wrauny.blogspot.com/2009/12/global-warming-leave-co2-alone.html
If the scientists accept the MODTRAN program calculations, then this entire thing is "once again" nothing but a complete scam, hoax or whatever. spent trillions on nonsense, and literally kill people by freezing them to death and impoverishing them by increasing their energy prices.

Here in the physics forum some seemingly "good guys" come up with the exact same thing as the blogger, just trying to get to the truth.
http://www.physicsforums.com/showthread.php?t=174215
Listen to RealScientists talking
"Look in the Modtran graph right below the output data, that should answer both questions. CO2 only radiates only with a certain narrow frequency spectrum. the first ppmv's saturate it rather quickly, then at higher CO2 concentrations the adjacent frequencies only get slowly affected.

Compare it with painting with a little transparent paint. The first layer gives the strongest coloring. Additional layers of paint only deepen the color slightly. This a 100% identical process, only in another frequency band.

....That brings to question, what does cause the earth to be warmer if ghgs don't have much of anything to do with it. It would appear that cloud cover might be the actual reason - that combined with albedo - as well as being the dominant reasons for variations."

http://www.junkscience.com/Greenhouse/co2greenhouse-X2.png

This is what happens every time I look into any of the green claims, it always turns to nonsense.

[questioner]

I am not saying this is authoritative, because I know there are many views, esp when the science is not settled.
http://www.davidarchibald.info/papers/S ... 202008.pdf

Starting on page 22 he talks about the decreasing logarithmic effect of CO2 on the greenhouse effect. Is this accepted by all scientists as pure science? He comes up with the same 3 degrees you mentioned, but we are already there. Do you know what chapter IPCC report discusses this?

"The effect of carbon dioxide on temperature is logarithmic and thus climate sensitivity decreases with increasing concentration. The first 20 ppm of carbon dioxide has a greater temperature effect than the next 400 ppm. The rate of annual increase in atmospheric carbon dioxide over the last 30 years has averaged 1.7 ppm. From the current level of 380 ppm, it is projected to rise to 420 ppm by 2030.
The projected 40 ppm increase reduces emission from the stratosphere to space from 279.6 watts/m2 to 279.2 watts/m2. Using the temperature response demonstrated by Idso (1998) of 0.1°C per watt/m2, this difference of 0.4 watts/m2 equates to an increase in atmospheric temperature of 0.04°C.
Increasing the carbon dioxide content by a further 200 ppm to 620 ppm, projected by 2150, results in a further 0.16°C increase in atmospheric temperature."

Not only is this paper not authoritative it is a piece of crap.
http://n3xus6.blogspot.com/2007/02/dd.html
He makes a strange choice of 5 stations within a few hundred miles of one another to represent the US, to prove the US has been cooling. He leaves out a bunch of data in an attempt to show correlation between solar cycle and Debilt temperature.
He also uses the Temperature of Central England Graph compiled by Lamb to illustrate the MWP, and doesn't mention that it is a local not a global temperature graph .
Using Idso's estimate of 0.1C for climate sensitivity is of course ridiculous. This is a low outlier. Archibald's own graph, on page 24 shows that. Even Lindzen the skeptic gives a value of 1C, versus the IPPC's nominal estimate of 3C.

Who the hell is David Archibald? Has he published anything peer reviewed? How did you come to choose this paper?

[glenncz]

The paper is only a "piece of crap" because it doesn't support your views. There may be some "theory" in it, but most of it is simply about sunspot cylces. Much of those graphs are not disputed, sunspots numbers and cycle lengths are easily measured. Certainly there is theory about the future. Also, it opened my eyes to CO2 saturation, which I never really explored before.

But of course, you just made an ad hominen attack, which is what usually happens, but seriously, I thought you could do better than that. I just printed out the article you referred to and will read it, I enjoy reading opposing points of views and trying to get to the truth of all things. And actually, I can see there is some dispute about CO2 saturation with reverse logarithmic effects.

We shall see.

[glenncz]

Q. I read that review but did not analyze it. Actually, I am not prepared to predict solar cycles and "future theories". I know that there is controversy regarding the sun cycles and I accept that. I only used the paper because it tipped me off to the logarithmic reverse saturation effect of CO2 on the greenhouse effect. What Archibald wrote in his paper about CO2 saturation does not seem that controversial. If what you and your pals say about Archibalds cherry-picking to make his future predictions is true, it is absolutely no different than the what IPCC et al is doing to skim/scam trillions of dollars from our world economy. Same exact thing! I'm not here to argue about predictions for the future because certainly the green movement has a complete monopoly on that issue. Or they did. Things have changed since ClimateGate and Dopenhagen, and stable temperatures.

[questioner]

Q. I read that review but did not analyze it. Actually, I am not prepared to predict solar cycles and "future theories". I know that there is controversy regarding the sun cycles and I accept that. I only used the paper because it tipped me off to the logarithmic reverse saturation effect of CO2 on the greenhouse effect. What Archibald wrote in his paper about CO2 saturation does not seem that controversial. If what you and your pals say about Archibalds cherry-picking to make his future predictions is true, it is absolutely no different than the what IPCC et al is doing to skim/scam trillions of dollars from our world economy. Same exact thing! I'm not here to argue about predictions for the future because certainly the green movement has a complete monopoly on that issue. Or they did. Things have changed since ClimateGate and Dopenhagen, and stable temperatures.

Explain where the IPCC is cherry picking data.
ClimateGate showed that scientists were irritated by AGW deniers who cherry picked data. The fact is that 95% of the climate data is in the public domain. There is nothing coming out of ClimateGate to change any of the peer reviewed papers that have been published.
At least you are not claiming it is cooling. How stable are the temperatures? What is the definition of stable. This Nov was a record high for the GISS global data base.

[Mike Davis]

Q:
It appears that you have not read any of the 4 IPCC annual reports which is all the evidence required to answer your question regarding Cherry Picking. The evidence is on every page that has words written on them. The entire purpose for creating the IPCC group was to "Cherry Pick" data to provide evidence that humans might has a role in climate change. They proved the theory that with control of the numbers one can get any answer desired. All that is required is a minor adjustment here and there. Ignore what does not conform to the desired results and you end up with the annual reports.

[questioner]

Q:
It appears that you have not read any of the 4 IPCC annual reports which is all the evidence required to answer your question regarding Cherry Picking. The evidence is on every page that has words written on them. The entire purpose for creating the IPCC group was to "Cherry Pick" data to provide evidence that humans might has a role in climate change. They proved the theory that with control of the numbers one can get any answer desired. All that is required is a minor adjustment here and there. Ignore what does not conform to the desired results and you end up with the annual reports.

This is one of your typical posts. A rant totally without any supporting evidence.