Paul Ostergaard writes via email:
Here is an interesting new paper that Miklos Zagoni has pointed me to via Judith Curry’s blog. This researcher in Germany has carried out a spectroscopic analysis of the impact of CO2 and other greenhouse gases’ contribution to warming.
It arrives (surprise!) at a value one seventh of the IPCC best estimate for Climate Sensitivity for a CO2 doubling. Looks intriguing at first blush…
The climate sensitivity CS as a measure for the temperature increase found, when the actual CO2-concentration is doubled, assumesCS = 0.41 ̊C for the tropical zone, CS = 0.40 ̊C for the moderate zones and CS = 0.92 ̊C for the polar zones. The weighted average over all regions as the global climate sensitivity is found to be CS = 0.45 ̊C with an estimated uncertainty of 30%, which mostly results from the lack of more precise data for the convection between the ground and atmosphere as well as the atmospheric backscattering…. The values for the global climate sensitivity published by the IPCC [3] cover a range from 2.1 ̊C – 4.4 ̊C with an average value of 3.2 ̊C, which is seven times larger than that predicted here.
Here is the link to the abstract:
http://meetingorganizer.copernicus.org/EGU2011/EGU2011-4505-1.pdf
The paper is being presented at the EGU General Assembly 2011 in Vienna.
Perhaps our WUWT readers can dissect this and see how well it holds up. It is important to verify if the paper’s methodology is sound.
===============================================================
How much CO2 really contributes to global warming? Spectroscopic
studies and modelling of the influence of H2O, CO2 and CH4 on our
climate
Hermann Harde
Helmut-Schmidt-Universität Hamburg, Germany
Based on the actual HITRAN’2008 database [1] detailed spectroscopic studies on the absorbance of the greenhouse gases water, carbon dioxide and methane in the atmosphere are presented. The objective of these investigations was to examine and to quantify with these newly available data the influence of these gases on our climate.
The line-by-line calculations for sun light from 0.1 – 8 m (short wavelength radiation) as well as those for the emitted earth radiation from 3 – 60 m (long wavelength radiation) show, that due to the strong overlap of the CO2 and CH4 spectra with the water vapour lines the influence of these gases is significantly reducing with increasing water vapour pressure, and that with increasing CO2-concentration well noticeable saturation effects are observed limiting substantially the impact of CO2 on the warm-up of the atmosphere.
For the water vapour, which in its concentration is considerably varying with the altitude above ground as well as with the climate zone, separate distributions for the tropes, the moderate zones and the polar regions are presented.
They are based on actual GPS-measurements of the water content in these zones [2] and are applied for calculating the absorbance in the respective regions. The vertical variation in humidity and temperature, in the partial gas pressures and the total pressure is considered for each zone separately by computing individual absorption spectra for up to 228 atmospheric layers from ground level up to 86 km height.
The propagation length of the sun light in these layers, which depends on the angle of incidence to the atmosphere and therefore on the geographic latitude, is included by considering the earth as a truncated icosahedron (bucky ball) consisting of 32 surfaces with well defined angles to the incoming radiation and assigning each of the areas to one of the three climate zones.
To identify the influence of the absorbing gases on the climate and particularly the effect of an increasing CO2- concentration on the warming of the earth, a two-layer climate model was developed, which describes the atmosphere and the ground as two layers acting simultaneously as absorbers and Planck radiators. Also heat transfer by convection between these layers and horizontally by winds or oceanic currents between the climate zones is considered.
At equilibrium each, the atmosphere as well as the ground, delivers as much power as it sucks up from the sun and the neighbouring layer or climate zone.With this model for each climate zone the temperature progression of the earth and the atmosphere is calculated as a function of the CO2-concentration and several other parameters like ozone and cloud absorption, short- and long-wavelength scattering at clouds as well as the reflection at the earth’s surface.
The simulations for the terrestrial and atmospheric warm-up show well attenuating and saturating progressions with increasing CO2-concentration, mainly caused by the strongly saturating absorption of the intensive CO2 bands and the interference with water lines. The climate sensitivity CS as a measure for the temperature increase found, when the actual CO2-concentration is doubled, assumesCS = 0.41°C for the tropical zone, CS = 0.40°C for the moderate zones and CS = 0.92°C for the polar zones. The weighted average over all regions as the global climate sensitivity is found to be CS = 0.45°C with an estimated uncertainty of 30%, which mostly results from the lack of more precise data for the convection between the ground and atmosphere as well as the atmospheric backscattering.
The values for the global climate sensitivity published by the IPCC [3] cover a range from 2.1°C – 4.4°C with an average value of 3.2°C, which is seven times larger than that predicted here.
studies and modelling of the influence of H2O, CO2 and CH4 on our
climate
Hermann Harde
Helmut-Schmidt-Universität Hamburg, Germany (harde@hsu-hh.de)
Based on the actual HITRAN’2008 database [1] detailed spectroscopic studies on the absorbance of the greenhouse
gases water, carbon dioxide and methane in the atmosphere are presented. The objective of these investigations
was to examine and to quantify with these newly available data the influence of these gases on our climate.
The line-by-line calculations for sun light from 0.1 – 8 m (short wavelength radiation) as well as those for the
emitted earth radiation from 3 – 60 m (long wavelength radiation) show, that due to the strong overlap of the CO2
and CH4 spectra with the water vapour lines the influence of these gases is significantly reducing with increasing
water vapour pressure, and that with increasing CO2-concentration well noticeable saturation effects are observed
limiting substantially the impact of CO2 on the warm-up of the atmosphere.
For the water vapour, which in its concentration is considerably varying with the altitude above ground as well as
with the climate zone, separate distributions for the tropes, the moderate zones and the polar regions are presented.
They are based on actual GPS-measurements of the water content in these zones [2] and are applied for calculating
the absorbance in the respective regions. The vertical variation in humidity and temperature, in the partial gas
pressures and the total pressure is considered for each zone separately by computing individual absorption spectra
for up to 228 atmospheric layers from ground level up to 86 km height.
The propagation length of the sun light in these layers, which depends on the angle of incidence to the atmosphere
and therefore on the geographic latitude, is included by considering the earth as a truncated icosahedron (bucky
ball) consisting of 32 surfaces with well defined angles to the incoming radiation and assigning each of the areas
to one of the three climate zones.
To identify the influence of the absorbing gases on the climate and particularly the effect of an increasing CO2-
concentration on the warming of the earth, a two-layer climate model was developed, which describes the atmosphere
and the ground as two layers acting simultaneously as absorbers and Planck radiators. Also heat transfer by
convection between these layers and horizontally by winds or oceanic currents between the climate zones is considered.
At equilibrium each, the atmosphere as well as the ground, delivers as much power as it sucks up from the
sun and the neighbouring layer or climate zone.With this model for each climate zone the temperature progression
of the earth and the atmosphere is calculated as a function of the CO2-concentration and several other parameters
like ozone and cloud absorption, short- and long-wavelength scattering at clouds as well as the reflection at the
earth’s surface.
The simulations for the terrestrial and atmospheric warm-up show well attenuating and saturating progressions with
increasing CO2-concentration, mainly caused by the strongly saturating absorption of the intensive CO2 bands and
the interference with water lines. The climate sensitivity CS as a measure for the temperature increase found, when
the actual CO2-concentration is doubled, assumesCS = 0.41°C for the tropical zone, CS = 0.40°C for the moderate
zones and CS = 0.92°C for the polar zones. The weighted average over all regions as the global climate sensitivity
is found to be CS = 0.45°C with an estimated uncertainty of 30%, which mostly results from the lack of more
precise data for the convection between the ground and atmosphere as well as the atmospheric backscattering.
The values for the global climate sensitivity published by the IPCC [3] cover a range from 2.1°C – 4.4°C with an
average value of 3.2°C, which is seven times larger than that predicted here.
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How long before RC ramps up to “debunk” this one? Surely they won’t let a paper like this stand unmolested.
I’ve often heard this argument made before, but I have never seen it in the literature before. It is interesting to see that it made it through peer-review. Of course, that does not mean the paper is accurate, but it will certainly stir the debate. Thank you for the find!
It looks like a big progress. I like “228 layers” and “86 km”, not “up to tropopause” only. The model also has 3 climate zones and includes polar zone (instead of having only two zones in infamous Myhre-1997 study). I like accounting for horizontal transport between zones, and account for clouds (I hope their parametrization is individual for each zone). Sounds very good. I’d like to see their equivalent of “radiative forcing”, although it seems like the article uses more physical approach and evaluates the state of new balance for each increment in CO2, so the illusory “radiative forcing” simply does not enter the picture.
If someone published a paper that found a sensitivity of 5 degrees C, and the paper abstract included the phrase “considering the earth as a truncated icosahedron (bucky ball) consisting of 32 surfaces”, how well would that fly around here?
Can we at least agree to perform calculations with a spherical earth?
Maybe the Union of Concerned Scientists can trot out Jeff Masters and waste everyone’s time with a conference call on this paper. They seem to be experts on cutting edge research topics.
The modelers can just add
FEEDBACK = FEEDBACK * 7
Whew! That was almost a funding crisis.
George Turner makes a good point. It appears the paper is calculating the no feedback sensitivity. This normally calculated by IPCC types as somewhere between 1.0 – 1.1C. Instead of being 1/7 of the IPCC estimate, it is really 40-45% of the IPCC view for no feedback sensitivity.
It’s a bit like comparing apples and oranges as the IPCC figure includes feedbacks, if you exclude the feed backs the result is in the lower range. I think they need to fix the abstract before it goes any further. I think this figure may even be in agreement with IPCC for C02 alone.
If this is a conference paper, it has probably not been peer reviewed. Give it the same intensity of scrutiny we would expect for papers we disagree with, and let the chips fall as they may.
syphax says: March 2, 2011 at 10:34 pm
If someone published a paper that found a sensitivity of 5 degrees C, and the paper abstract included the phrase “considering the earth as a truncated icosahedron (bucky ball) consisting of 32 surfaces”, how well would that fly around here?
Not ideal, but it does eliminate rounding errors.
Doesn’t surprise me in the slightest: 3K climate sensitivity in AR4 depends on imaginary ‘cloud albedo effect’ cooling. By 2004, NASA knew it couldn’t be proved experimentally so it’s purely theoretical but the aerosol optical physics is wrong.
This goes back to the 1950s when Van de Hulst explained greater than expected backscattering from sols as a form of directed diffuse backscattering driven by strong asymmetry. Sagan picked it up and his analysis was used by Lacis and Hansen at GISS. The equation [and variants] apparently fits albedo-optical depth data but when used to predict albedo change when pollution reduces cloud droplet size, goes the wrong way for thicker clouds.
It’s because there’s a second optical process, direct backscattering at the upper cloud boundary, strongly dependent on droplet size. You can easily prove it by looking at clouds about to rain: they get very much darker underneath due to the shielding so smaller droplet size reduces the albedo of thicker clouds.
Therefore, all the climate models are broken. In 2004, apparently to justify incorporation of the cooling in AR4, NASA claimed a ‘surface reflection’ argument: http://geo.arc.nasa.gov/sgg/singh/winners4.html
This replaced Twomey’s partially correct physics which he had warned couldn’t be extrapolated to thicker clouds. As any competent person should have known, there’s no such physics. AR4 was known by some to be incorrect before it was published.
What appears to have been the biggest scientific fraud in History is being challenged.
considering the earth as a truncated icosahedron (bucky ball) consisting of 32 surfaces …….. or 20 surfaces ? as icos means 20.
http://mathworld.wolfram.com/Icosahedron.html
[Comment : Back in my schooldays, I think the object referred to (truncated icosahedron) was called an icosidodecahedron. It has 32 faces – 20 triangular and 12 pentagonal. http://mathworld.wolfram.com/Icosidodecahedron.html – mj]
The 0,45K CS matches the simple finding, that it takes around 9,25 “doublings” of CO2 to match the total CO2 effect:
http://hidethedecline.eu/pages/posts/925—a-factor-that-could-close-the-global-warming-debate-193.php
9,25 * 0,45 = 4,2 K for total CO2 contribution. This is around 13% of the supposed total green house gas effect of the Earth (33K) and thus the 0,45 K sounds physically possible unlike the IPCC/Hansen estimates.
K.R. Frank
This problem has an easy and convenient solution.
fudge_factor = 7
syphax asks, “Can we at least agree to perform calculations with a spherical earth?” after complaining about “truncated icosahedron consisting of 32 surfaces”
Would you feel better if the author would use climatardant jargon “using T31 grid”?
http://thenerdiestshirts.com/images/thumbs/math-shirt-t-icosahedron-white-325px.gif
[Comment – I stand corrected, it appears this is indeed the “buckyball”. http://www.angelfire.com/rachelgladstone/football.html – mj]
Hint to European scientists publishing in English: dig up a native speaker co-author. The text to understand easier much could be would, likely very!
Thanks.
It sounds like the author of this paper thinks that the standard IPCC models do not combine the atmospheric heat-trapping effects of multiple green-house gasses correctly — specifically, that these models do not correctly allow for the interaction of the water vapor and CO2 absorptions. If he’s correct, this could be a big “gotcha” for the standard IPCC climate models, because it would mean that the standard IPCC approach is “over-counting” the combined effect of CO2 and water vapor absorption by assuming that each gas is absorbs as if the other gas was not present instead of — as this author does — calculating how each gas takes away some of the radiation the other gas needs in order to reach its full greenhouse efficiency.
If I understand the abstract correctly, water vapour is included.
So what other feedbacks are commentors refering to?
I fear this model has some of the same limitations as the AGW ones but it does seem to be no worse. Those who complain about the icosidodecahedran simplifiction are clutching at straws. The effect of this approximation has got to be tiny. Those who compare this paper’s findings with the IPPC’s estimate ‘without feedback’ may have a valid point but in the linked abstract they say they have used actual measured figures for the amount of water vapour at each altitude so it sound like the biggest feedback is included. Since the IPPC modelled feedback is very contentious and yet unverified this objection also looks a bit deperate.
My personal doubt is whether they have included the temperature of the tropopause in their model and whether they have considered it to be constant. If the ‘well known saturation effects’ result in an increase in height of the tropopause and reduction in its temperature the amount of energy radiated from the top of the troposphere (particularly by CO2) will fall. I feel that this can only be determined by measurement. Some of you may remember the time when we did research which included measurement and model validation.
This result is interesting. It isn’t a pure climate sensitivity study, but is a merged CO2 forcing and sensitivity combined effect. I have to admit that it gives very comparable results to what I have gotten from my analysis.
I do like the latitude based results as the impact of water vapor is dominant.
Using his results it can be estimated that the north pole has experienced 0.3 C warming as a result of CO2. The world as a whole about 0.15C. I will do a full analysis and post in the next few days.
http://theinconvenientskeptic.com/
It’s all a load of rubbish…..its not a pal reviewed paper therefore it’s voodoo science.
The fact that the paper misses the point of feedback mechanisms in comparison with the IPCC range is telling. What I would like to see specifically identified is the specific points where this model differs from others – rather than a ground up construction with no reference points. As it stands, I think this has very little value. In effect, it says your other models are broken because I have one here which disagrees.
Yes, BaaHumbug and ZZZ . Water vapor is the predominant greenhouse gas by far. CO2 is a bit player at best. Not only that but low clouds are clearly a large negative feedback keeping the system stable. As CO2 doesn’t change phase at temperatures/pressures that exist anywhere in the atmosphere it simply cannot compete.
Harde is not alone in finding a value much less than 1 degree C for the increase in average global earth’s surface temperature per doubling of atmospheric CO2. A number of studies which have included empirical as well as theoretical arguments have also come up with values in the <<1 degree C range. For instance Newell and Dopplick, 1979 (J. Applied Meteorology, 18, 822-825), using a radiation flux model, suggested around 0.25 degrees C (without H2O feedback). This compares with the value of 1.2 degrees adopted by the IPCC.
It’s funny how each week it seems to get worse and worse for the IPCC / Warm.
Estimated CO2 Warming Cut By 65%
http://theresilientearth.com/?q=content/estimated-co2-warming-cut-65
http://www.nature.com/ngeo/journal/v3/n9/full/ngeo932.html
“Amplification of Global Warming by Carbon-Cycle Feedback Significantly Less Than Thought, Study Suggests”
http://www.sciencedaily.com/releases/2010/01/100127134721.htm
http://www.nature.com/nature/journal/v463/n7280/full/nature08769.html