Discussion > Does Climate Science Exist?
"The direct calculation for forcing due to CO2 is ∆F=5.35ln (C/Co)"
If I'd have put the 5.35 in my equation we would have got the same answer - blunder.
I see you get your info from SkS Dana, the Nazi messenger, tried to make out that the rise in temperature between 1910 and 1940 was caused by human by alluding to the fact that 0.29C was very close to 0.45C. In his dreams. The thing is that the master misinformation could have got the 0.45C if he'd been a little more imaginative.
geronimo
"5.35ln (C/Co)"
Part of the folklore of climate science. It has the appearance of a formula derived analytically from physical laws. But you'd be wrong if you thought that was how it had been obtained.
The Myhre, Highwood, Shine, Stordal paper obtain the 5.35 coefficient by fitting a log curve to the output of numerical models (unvalidated models). Accuracy to two decimal places is implied but no estimate of accuracy is actually given. Would such an omission be accepted from an A-level physics student?
The previous best estimate (IPCC) for the coefficient differed by 15% so the +/- 0.01 implied accuracy is probably, shall we say, 'optimistic'. Yet everyone in climate science, from EM and downwards, quotes it as something having mathematical precision.
The C values ranged over about 1:4 so OK for "doubling of CO2" estimates, but far from establishing the validity of the formula for all C. Steve McIntyre pointed out that a square root formula could have been fitted just as well.
Martin A
Martin A
Validation for the forcing model comes from hitrans, the database of CO2 properties and atmospheric behaviour put together by the USAF while developing heat seeking air-to-air missiles and ballistic missile launch detectors.
Entropic man
ABSTRACT
(...) The HITRAN molecular absorption compilation is comprised of six major components structured into folders that are freely accessible on the internet. These folders consist of the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, ultraviolet spectroscopic parameters, aerosol indices of refraction, collision-induced absorption data and general tables such as partition sums that apply globally to the data. (...)
Martin A
Geronimo
I got the temperature figures from GISS.
Lambda matches the IPCC mid-range prediction of 3C/doubling.
It occurs to me that if ∆T=lambda∆F, then the same formula let's us calculate approximate values for lambda from the actual temperatures ( though it assumes that only CO2 is varying.)
Lambda=∆T/∆F
For 1910-1940 lambda=0.46/0.36=1.28K/w/m2. In more conventional terminology a climate sensitivity of 1 is 0.27K/w/m2. A lambda of 1.28 becomes a climate sensitivity of 1.28/0.27=4.7
For 1950-2012 lambda=0.71/1.3=0.55. That becomes 0.55/0.27=2.03.
Just for fun I tried the whole period 1910-2012.
∆F is 5.35ln(395/290)=1.65
∆T is -0.44 to 0.62 = 1.06C.
Lambda=1.06/1.65= 0.64. Climate sensitivity is 0.64/0.27=2.38.
The fun of this is that it is science we can do ourselves, without being told what the answers should be. It lets us crosscheck the professionals.
Entropic man
Martin A
That's the one. Unfortunately "freely available" is a slight exaggeration, perhaps a hangover from their military research origins.
Entropic man
Looks reasonably accessible. http://www.hitran.org/please-register/
I think we may have different things in mind for 'validated'. No doubt accurate values from physical measurements and archived in HITRAN would have been used for the parameters of the models wherever possible.
But, since radiative forcing, from its definition, cannot be directly measured physically, it's hard to see how the models used could have been validated in the normal sense of having their outputs compared directly with physical measurements of the same things.
Martin A
Martin A
Actually you can validate in the lab. The apparatus is a long tube with IR transparent ends. Fit an IR emitter to one end and an IR spectrometer to each end. You can use mirrors to increase the path length.
This allows you to put in 15 micrometre radiation and detect both the transmitted and back radiation. By varying the pressure and composition of tha e gas in the tube you can simulate differences in the atmosphere.
You can then plot transmitted and back radiation against CO2 concentration and derive the formula from the best fit curve.
Entropic man
" There are plenty of people claiming (and believing) that they are ' climate
scientists '. But in what sense does climate science exist as a subject?"
Martin, I ran climate models for a few years at Reading, the subject was called
Meteorology. There are quite a lot of interesting experiments you can run with
them to get some kind of understanding of how the weather works (ie I was
looking at the importance of the mountains and oceans in controlling the jet
stream... The Rockies and warm Gulf of Mexico give it a generally SW flow
over Britain, hence our generally warm weather. Nothing to do with the gulf
stream....)
Though potentially interesting it obviously has no practical use at all apart
from weather forecasting really and that should pretty cheap to do well
enough these days.
Rob Burton
10:17 PM Entropic man
EM. If you have devised a method for measuring radiative forcing, you should write it up for publication so that it can be put to use. It will be a significant advance. Until now, the consensus has been that it is a concept that exists in model form only.
Martin A
Martin A
Already done. There is even a monitoring network in place.
As an engineer you may be interested in the design .
And this is what you can do with it. Observational determination of surface radiative forcing by CO2 from 2000 to 2010
Sorry about the paywall.
What intrigues me is that they get a decadal increase of 0.2 +/- 0.07 w/m2 and the technique is sensitive enough to pick up the 0.02 seasonal variation.
How does this compare with theory?
CO2 increased from 370-390ppm. The expected forcing increase would be 5.35ln(390/370)=0.27w/m2.
Observed- 0.2+/- 0.7. Expected 0.27.
Entropic man
EM
If Martin A pays to view that article and it turns out to be the junk that I anticipate then I feel sure I can get you banned at last and you will have proved just how low you are willing to go.
Dung
Dung
Perhaps you should read the article, or at least the abstract and Figure 4. It provides an observed correalation between CO2 concentration and radiative forcing. The size of the observed forcing change also fits well with the theoretical CO2 forcing change predicted by radiative physics.
This is an example of what I was discussing elsewhere. The scientific method compares observational results with different hypotheses and judges their value accordingly.
This experiment produced results which matched the prediction of the CO2 greenhouse effect hypothesis. It did not fit the prediction of your hypothesis, that there would be no correlation between CO2 concentration and forcing.
Entropic man
How does this compare
CO2 increased from 370-390ppm. The expected forcing increase would be 5.35ln(390/370)=0.27w/m2.
Observed- 0.2+/- 0.7. Expected 0.27.
EM - no uncertainty range has even been given, so far as I know for your beloved formula. Comparing a theoretical result, for which no uncertainty range has been given and treating it as if it had no uncertainty gives an optimistic view.
My calculation gives 5.35ln(390/370) = 0.282... So your 0.27 w(sic)/m2 is a bit understated. I think using the actual CO2 values (rather than rounded to integer) gives a result a bit bigger still.
Pity the abstract does not give more info. "with respective uncertainties of ±0.06 W m−2 per decade and ±0.07 W m−2 per decade". "Uncertainties" - standard deviation estimate? Some sort of confidence limit? Who knows?
They say "0.2" in the abstract ? Why not "0.20", if that is the actual result?
Too bad the paper is not freely available. Could be highly significant, could be rubbish. Hard even to make out what it's actually saying.
Martin A
Martin A
I can't get through the paywall either, but they are referring to them in the way usually used for 95% confidence limits.
Don't have confidence limits for the formula. I might point out that the bigger its uncertainty the better the overlap with the observations.
Remember that the formula applies to an ideal atmosphere with gases only.The real atmosphere contains aerosol particles which will scatter photons, or absorb them and reradite at different frequencies.This will reduce forcing measured at the surface, so the calculated value represents an upper limit, not the most likely observed value.
Entropic man
EM - what do you think are they actually measuring? The IR radiation arriving at ground level and (presumably identified from its spectral characteristics) radiated by CO2 in the atmosphere?
Martin A
Getting back to something related to the original topic of this discussion thread. Pointman, never one to mince words:
"....alarmist climate science is essentially a criminal enterprise..."
(halfway down the page)
Martin A
What they would be measuring is IR downwelling radiation from a clear sky. The signature of CO2 is the wavelength, centred on 15 micrometres with some band spreading out 13 and 17micrometres.
PS I reran the calculation and got 0.28. Senility and finger trouble strike again. ☺
Entropic man
Martin A
What awes me about the climate conspiracy is the scale on which it operates.
THEY started in the 19th century. John Tyndall was induced to fiddle his infra-red spectra. Arrhenius was told to make false calculations and write his book..
Tens of thousands of weather station readers were told to overread their thermometers, as were the crew of every ship which ever took a temperature measurement.Even Putin and the Soviet Union are involved, rigging Siberian temperatures and digging fake blowholes in the tundra.
Think of the care and subtlety with which urban heat island effects were incorporated. How carefully the ARGO float network and its predecessors were manipulated to show increasing ocean heat content.
Think of the satellite operators at NASA and elsewhere who have generated false insolation and energy flow data.
What about all those glaciologists who have photoshopped fake photos of receding glaciers and the Antarctic explorers who painted the Larsen ice sheets dark blue to make them appear to vanish.
Who fiddled the tide guage and satellite data to show rising sea levels?
The editors and reviewers of every scientific journal must be involved. Why else would they publish the rubbish produced by thousands of mteororologists, oceanographers, astronomers, polar explorers, physicists biologists, glaciologists and statisticians; all in on the plot. They must also reject papers published by those brave few willing to write the truth.
Coordinating the conspiracy must take thousands of people in a couple of skyscrapers. Perhaps the evidence of the conspiracy was getting too obvious and the World Trade Centre was demolished to destroy the records.
Tens of thousands of conspirators get a cut of trillions of dollars. The millions of dollars each receives is salted away, while THEY live modest suburban lifestyles.
THEIR final subtlety is to reveal the truth on anonymous blogs, written in an emotional ranting style full of insults and giving no evidence. Surely no one would believe it and the secret would be safe.
Entropic man
Do you think they make the assumption that outgoing IR (outgoing to space) is the same as downwelling? I'd have thought they are not the same thing. But, presumably, it's the outgoing that matters, not what's bouncing around inside the atmosphere or between the surface and the lower atmosphere.
0.27, 0.28, ..... ???
Let's redo the calculation with the actual CO2 values rather than using EM style values rounded to integers...
Taking the Mauna Loa CO2 annual mean data
2000 369.52ppm
2010 389.85ppm
5.35 ln(389.85/369.52) = 0.2865... = 0.29 (to two decimal places). So even less overlap.
"the bigger its uncertainty the better the overlap with the observations."
Well yes, but there is an implied fallacy in there somewhere... If the uncertainty in the model result were *huge*, the overlap would be *perfect*.
A bit like Richard Betts saying that the "pause*" was predicted by the Met Office model because the variability of their model's output is so big. Or my computer program that predicts perfectly the throw of the dice - its output is (every time) 3, with an uncertainty range of ± 4.
__________________________________________________________________________________
* As has been pointed out before, it's can only be legitimately/scientifically be termed a "pause" if the future is known. The use of the term "pause" is one of the 10,000 things that make me tend to disbelieve *anything* that comes from "climate science". It's a bullshitter's term; not a scientist's.
Martin A
Martin A
IR in the atmosphere starts as radiation from the surface. Spectrum depends on temperature and the materials involved but approximates to the prediction of the Stefan-Boltzmann equation. At some wavelengths this leaves the atmosphere directly and becomes OLR detectable by satellites.
At wavelengths absorbed by greenhouse gases a portion of the radiation is absorbed and reemitted in all directions. This is, as you aptly describe, "what's bouncing around inside the atmosphere".
Sooner or later this either gets high enough to join the OLR or is reabsorbed by the surface as downwelling radiation/radiative forcing.
Without CO2 all the 13-17micrometre radiation from the surface becomes OLR. As concentration increases a higher proportion becomes radiative forcing. When there is enough CO2 for the atmosphere to saturate, 50% of the surface radiation becomes OLR and the other 50% becomes radiative forcing.
Interestingly, at the 15 micrometer spot frequency CO2 may already have saturated, with most of the increasing forcing coming from either side.
I have to go out. More later
Entropic man
EM - Two or three years ago I think I had a reasonable understanding of this stuff. But my understanding seems to have nearly all evaporated. A few hours at SOD would bring it back no doubt.
"IR in the atmosphere starts as radiation from the surface."
Or can it also start as radiation from water vapour (or other greenouse gas) that has been warmed by non-radiation transport of heat? (Latent heat of condensation of water vapour lifted by convection, convection of warm air,...?)
To you (as I understand) "radiative forcing" = "downwelling IR absorbed at the surface". Have I understood right?
Given that there are other energy/heat transport mechanisms involved, is there any reason to think
"50% of the surface radiation becomes OLR and the other 50% becomes radiative forcing."
other than in an idealised model that neglects non radiative heat transfer? (Such as the simple model used to calculate a crude estimate of what the temperature of the Earth would be without the greenhouse effect, for example.)
Does the paper's use of only clear sky measurements ensure the 50%, 50%? (Not so far as I can see - even with clear sky (which would mostly rule out heat transfer by evaporation/condensation of H2O) there will still be non-radiative heat transfer going on.)
The only purely radiative transfer that is certain is the final radiation to space....
Martin A
When EM relies on conspiracy strawmen he reduces himself from true believer to dumbass troll.
It is the work of Tyndall et al and the data that supports the skeptics. It takes climate kooks and true believers to distort the data, massage the data, and refuse to consider the implications of their falsified predictions to keep their faith alive.
Climate kooks rely on conspiratorial phantoms to fuel the skepticism that reasonable people feel towards the end-of-the-world bullshit EM and Raff regurgitate. And instead of being honest about it, they have to fall back on assigning bad motives to skeptics.
It is so tedious when the climate faithful twist their failed predictions into support for their apocalyptic idiocy.
hunter
If there was a clear example of somebody being in denial about some serious issues, Entropic Man gives it above.
And Entropic Man also likes to deny that anybody is making more than a modest living from their climate science activities.
... live modest suburban lifestyles.
Please spare us yet another repetition. It's boring and it does not show you in a good light. The reality is that there are an awful lot of people making a much more comfortable living out of climate science than they would have had from say schoolteaching or supermarket management.
What is a typical salary for a tenured climate science professor in the USA?. Over $100,000. Plus several pleasant conference trips to exotic locations. Plus consultancy engagements (EPA, NASA,...) amounting to 25% - 30% of their university salary. In terms of income and security, far above what the average US citizen has to get by on.
Similar comparisons for UK professors. £75,000 + salary.
And for UK Met Office scientific staff - (plus their inflation proofed pension - an immensely better deal than the typical UK citizen's defined contribution pension.)
Big Oil
Do not patronise me, EM, and do not make presumptions on my reference knowledge or lack of. I have had discussion with one person who tried to convince me that the MWP and Greenland farming was localised to Greenland and was a myth created by “deniers”. It did not take long to find a site that had linked many other proxy investigations around the world that showed the MWP was real, though cannot recall any of them showing “spikes”; one simple point to note – I would contend that a “spike” can only refer to an acknowledged reading, and cannot be deduced from proxies; any “spikes” shown would be treated with a great deal of caution, not, as you seem to imply, to be trumpeted as yet more “proof” of your myth.
You are right there, even when those holding the minority opinion have the loudest voices, and are in control of the mainstream media. I had no intention of insulting you; I was just making an observation.