it is a very one sided approach. i ll try to comment more later.
Lee,
"The radiative balance idea applies OVER TIME. If there is an imbalance, the planet will warm or cool until it gets back into balance, where incoming and outgoing energy are equal."
Look, you are going around in circles now. This is where I applied the (radiant energy in) > (radiant energy out) statement. And for the steady-state situation you are trying to imply it is a correct statement. There is no such equilibrium "radiative balance".
Also I'd like you to please tell me where this claimed "calculation" for the non-feedback CO2 sensitivity can be found.
You have danced around this point since the beginning. Below is a recounting of your posts on the subject.
"The coupled GCM models do NOT HAVE ANY ASSIGNED CO2 SENSITIVITY!! CO2 sensitivity comes OUt of the models."
So much for your claim of a simple "calculation that everyone agrees on".
"This is basic radiative physics - that you don't know this indicts your knowledge base."
Again if it is so basic please stop making insulting noises and just produce the damn thing.
"The calculated forcing for a doubling of CO2 is about 3.7 w/m2. The value is accepted by nearly everyone, even most of the staunchest denialists. Try this link."
Here is the entirety of the information at the link you provided.
6.3.1 Carbon Dioxide
IPCC (1990) and the SAR used a radiative forcing of 4.37 Wm-2 for a doubling of CO2 calculated with a simplified expression. Since then several studies, including some using GCMs (Mitchell and Johns, 1997; Ramaswamy and Chen, 1997b; Hansen et al., 1998), have calculated a lower radiative forcing due to CO2 (Pinnock et al., 1995; Roehl et al., 1995; Myhre and Stordal, 1997; Myhre et al., 1998b; Jain et al., 2000). The newer estimates of radiative forcing due to a doubling of CO2 are between 3.5 and 4.1 Wm-2 with the relevant species and various overlaps between greenhouse gases included. The lower forcing in the cited newer studies is due to an accounting of the stratospheric temperature adjustment which was not properly taken into account in the simplified expression used in IPCC (1990) and the SAR (Myhre et al., 1998b). In Myhre et al. (1998b) and Jain et al. (2000), the short-wave forcing due to CO2 is also included, an effect not taken into account in the SAR. The short-wave effect results in a negative forcing contribution for the surface-troposphere system owing to the extra absorption due to CO2 in the stratosphere; however, this effect is relatively small compared to the total radiative forcing (< 5%).
The new best estimate based on the published results for the radiative forcing due to a doubling of CO2 is 3.7 Wm-2, which is a reduction of 15% compared to the SAR. The forcing since pre-industrial times in the SAR was estimated to be 1.56 Wm-2; this is now altered to 1.46 Wm-2 in accordance with the discussion above. The overall decrease of about 6% (from 1.56 to 1.46) accounts for the above effect and also accounts for the increase in CO2 concentration since the time period considered in the SAR (the latter effect, by itself, yields an increase in the forcing of about 10%).
While an updating of the simplified expressions to account for the stratospheric adjustment becomes necessary for radiative forcing estimates, it is noted that GCM simulations of CO2-induced climate effects already account for this physical effect implicitly (see also Chapter 9). In some climate studies, the sum of the non-CO2 well-mixed greenhouse gases forcing is represented by that due to an equivalent amount of CO2. Because the CO2 forcing in the SAR was higher than the new estimate, the use of the equivalent CO2 concept would underestimate the impact of the non-CO2 well-mixed gases, if the IPCC values of radiative forcing were used in the scaling operation.
Note it says that they started with a value "calculated with a simplified expression" in 1990 but of course doesn't actually cite the calculation and decided later, based on other techniques and studies, that it was too high.
Then they used various methods including ones using GCMs and now have several different values that vary according to various assumptions despite your "everyone agrees" remarks.
So much for a simple calculation to obtain CO2 climate sensitivity.
When I pinned you down and asked again for this calculation that everyone agrees on you posted this.
Uh, codes? The first link is botched and goes no where, and the second goes to modtran, a computer model that magically spits out the ansewr if you give it input parameters.
Again neither of these is a "simple calculation" based on "basic radiative physics".
After some discussion of thermodynamics you posted.
"But there are only two issues in play. 1. What does the increase in back-scattered radiative energy from the increased CO2 do to the energy retention time in the system and therefore the total energy retained in the system. This is a 'simple' 2D radiative transfer calculation of a new state given a simple addition of a greenhouse gas to the current observed state. 2. How much warming is necessary to come into radiative balance with the increased energy in the atmosphere. This is a 'simple' gray body calculation."
Note that you again assert that there exists a "simple" 2-D radiative transfer calculation for the climate sensitivity to a doubling of CO2.
OK then where the hell is it?!
Most recently, in your last post you say, "First, it isn't a simple linear calculation - it is an integration across the atmospheric column of radiative transfer, using the known input of the sun, the known temperature and composition of the atmosphere, and the known absorption, emission, and collision properties of those gasses."
For the last time I ask you to produce this "simple 2-D calculation" (that you now call an "integration")not a link to some website, but the actual calculation.
Lance, stop being such a vapid idiot, please.
""The calculated forcing for a doubling of CO2 is about 3.7 w/m2. The value is accepted by nearly everyone, even most of the staunchest denialists. Try this link."
Here is the entirety of the information at the link you provided."
Lance, re-read the text you posted here. See this:
"have calculated a lower radiative forcing due to CO2 (Pinnock et al., 1995; Roehl et al., 1995; Myhre and Stordal, 1997; Myhre et al., 1998b; Jain et al., 2000). The newer estimates of radiative forcing due to a doubling of CO2 are between 3.5 and 4.1 Wm-2 with the relevant species and various overlaps between greenhouse gases included."
See the names and date in parentheses, Lance? Those are called "citations." They give you the information necessary to go GET THE DAMN PAPERS AND READ THEM!!!!
---
"Then they used various methods including ones using GCMs and now have several different values that vary according to various assumptions despite your "everyone agrees" remarks."
Christ almighty...
The estimates range between 3.5 and 4.1 W/m2. That isn't plus-or-minus standard error, Lance. That is the entire range, between most extreme results. The most likely value of 3.7 reflects the range and distribution of those estimates, none of which are away from that value by more than - 0.2W/m2 or +0.4W/m2, . You are arguing that this shows some kind of practical disagreement in the forcing estimate? Even the lowest of those estimates yields a sensitivity of 1C, and the highest about 1.3C or so. You think this is something you can use to dispute the value I cited of 1.1, in an argument where you are claiming that the 'real' value is some fraction of that?? Get fucking real.
More important, lose the intentional ignorance as debate tactic, Lance. It is intellectually lazy and dishonest. You claim to be a physicist. I gave you a link to a summary of the knowledge, with CITATIONS TO THE PRIMARY FUCKING PAPERS from which the summary was derived and the values taken - and you sit there and complain that I didn't show you the calculations? In my field - biology - I learned how to use a citation to track down a paper about 3 weeks into my freshman year. Don't they teach that to you physicists?
Lance, try separating the run together words in the above url with underlines.
Miranda Devine has an article in today's smh about World Youth Day, and how great and beautiful and "radiant" Catholic youth is compared to other kinds of people who are "aggressive secularists", and full of "nihilism", "rancid negativity" etc.
But the bit that I want to focus on is:
"Living in an era when faith and reason, art and mathematics, were inextricably linked, Renaissance artists would regard modern relativistic notions of beauty as ludicrous."
Now look: I read about the whole Alan Sokal thing, and I think its great that the spotlight was put on various humanities departments to lift their game, especially when it comes to drawing analogies to the weirdness in contemporary science when trying to make a philosophical point or comment on society or life.
But it seems to be increasingly common for people - especially in the blogosphere - to smear science and smear their ideological opponents as being pomo's, or relativists - without ever articulating exactly what they find so objectionable in their opponents argument. Its just a one word insult.
I think that is pathetic.
Like many ideas about the world, (e.g. evolution, climate change, psychotherapy, economic rationalism), postmodern theory can be validly challenged and criticised. But a lot of it makes sense, or has some intellectual value, or is at least thought provoking in a good way, and to use a label like 'pomo' or 'relativist' as a one word insult is anti-intellectual.
It reminds me of how climate sceptics have successfully created a popular meme that there is something theological about climate change science. The whole religious metaphor to characterise the majority of people who are moving in accordance with mainstream science and politics infuriates me. What a joke.
I am moodily expecting to see an increasing use of terms like 'relativist' and 'post-modernist' in pitiful ideological attacks against science and to score cheap ideological points from now on.
Not to mention also, Lance, that the broken link you disparage is obviously a wikipedia link, and is obviously to something called "List of atmospheric radiative transfer codes."
Links get broken by blogs - its fairly common. Intelligent people who see a wikipedia link to a list of radiative transfer codes, and are asking about such radiative transfer calculations, would freaking FIND a wikipedia page that is a list of radiative transfer codes. Failure to find that page is clear willful ignorance.
Not to mention further that you completely ignored the part - in the post you are specifically responding to - about the simplification in this particular calculation.
And you wonder why people get frustrated with you.
Upon reflection, I have decided that this statement from my earlier post:
"the 2nd law has no bearing on the radiative balance condition, which is a simple statement of the first law, applied to a nonequilibrium steady state."
is incorrect. It's incorrect in a very interesting way - the 2nd law is actually used to derive a crucial part of the radiative balance condition ! The calculation of outward radiative flux, whether crude (Stefan-Boltzmann) or sophisticated (line-by-line radiative transfer codes) literally has the 2nd law built into it. Stefan-Boltzmann, Kirchoff's Law, and the Wien Displacement Law can all be (and originally were) derived from the 2nd Law.
Lance: you've probably taken at least one and probably more than one course in Statistical Mechanics. Did you study Linear Response Theory ? Climate sensitivity is exactly analogous to LRT. As long as the change in the forcing is small compared to the overall forcing, you can calculate the response to a change in forcing from the equilibrium properties of the system. The Kubo Formula for electrical conductivity works for real electrons in real circuits, even though real electrical currents are (necessarily) far from equilibrium.
You OK Lee?
In my last post replace: "As long as the change in the forcing is small compared to the overall forcing"
with "as long as the change in the magnitude of the driving force..." or something equivalent. "Radiative forcing", by definition, is of course already a differential quantity - it's the result of the change, not the thing that is changed.
where you see the pointer:> Broken links
It's the software (which mangles underscores)
That's a feature, and explained right above the big empty box with the line around it at the end of the thread. See:
Comments: (you may use HTML tags or markdown for style)
Our host only had to explain this to me about three times that I can recall (no doubt after cleaning up messes I left til patience wore thin at my lack of reading comprehension).
Clues. So common, so hard to see. Get one today.
You OK Lee?
I'm worried, too. He underreacted to Lance's lying, dishonest, repetitive act.
It's been ages since we were treated to a Fumento piece. Has Mikey retired?
Robert P.,
While I didn't cover linear response theory in my studies of thermodynamics it did come up in a solid state quantum physics course.
As I recall it involved the time dependent response to an oscillating system to a small perturbation described using the Hamiltonian.
I'm not sure I understand its application to climate sensitivity.
"This article addresses new satellite and modeling evidence that previous satellite diagnoses of high climate sensitivity--which directly translate into predictions of dangerous levels of global warming--contain a large spurious bias. It is shown that those exaggerated estimates were the result of faulty assumptions regarding clouds when analyzing variations in average global temperature and average reflected sunlight off of the Earth. "
Lee,
The studies that are cited in the IPCC link you provided do not use a "calculation" based on "basic radiative" physics, simple or otherwise, as you claim. I know; I have read at least the abstract of all of them. Most use computer climate models and some just make corrections to the accepted estimate based on other factors such as short wave interactions with the stratosphere (Myhre et al. (1998b) and Jain et al. (2000)).
You can't provide a "simple calculation" for non-feedback CO2 climate sensitivity that "everyone agrees on" because one does not exist.
Screaming profanity laced insults changes that fact not one wit.
These non-feedback Co2 climate sensitivity estimates are based on highly simplified assumptions. As I said earlier since the figure is usually estimated at around 1 degree C for a doubling of CO2 I don't generally argue about it, but to assert that it is a "fact" is to overstate the confidence that should be placed in such a number.
Why do the Deniers infest the Scientific American comments section to such a degree? The S.A is pretty decent at reporting the issue. Is it the high profile that the magazine occupies among the popular science publications?
Lance - BS.
Look at the Collins et al 2006, for example,for a table listing the line-by-line codes they evaluated. Look at the wikipedia page I cited for a larger listing of line-by-line radiative transfer codes.
Those are not 'simple' calculations in the sense that you can write them down and solve for "x." They are very large and complicated calculations - but not complex calculations. They are simple in that they arrive at unique answers, based on known physics and known atmosphere profiles. Your 'complexity' criticisms of the climate models do not apply to these line by line codes. Versions of them are embedded in the climate models, but they are not the climate models, and they can be and are run independent of the models.
The "correcting" papers you dismiss are in fact runs of the line-by-line codes, with additional terms added for lower-order effects. Your continuing refusal to acknowledge the existence of these codes is getting absurd, Lance. Your refusal to acknowledge the general acceptance of these values is absurd as well. Spencer accepts a 2xCO2 forcing value near 1C - he thinks negative feedback reduces the with-feedback response to a much smaller value. Hell, even Monckton accepts it, although he doesn't seem to realize he does. He starts with a value in this range before he confuses forcing with temperature and arbitrarily divides the forcing value by three because he doesn't see trop trop warming.
--
And yes, the non-feedback CO2 warming values are based on highly simplifying assumption. That highly-simplifying assumption is that THERE IS NO FEEDBACK. That is why it is the non-feedback value. This is definitional.
The problem then simplifies to:
1. Given 2xCO2, what is the change in radiation transfer characteristics. The line by line codes provides that answer. It adds 3.5 - 4.1 w/m2 of forcing.
2. Given 3.5-4.1 w/m2 of additional forcing and no change in the gray-body characteristics of the earth other than that caused directly by the added CO2 (because there is no feedback, so nothing else changes) how much must the planet surface and atmosphere heat up to radiate an additional 3.5 - 4.1 w/m2, to balance that additional forcing. The answer is 1C - 1.3C at the surface.
What exactly do you see here, Lance, that is inappropriately simplified for the problem as stated? Be specific.
Lee,
You're obviously an intelligent person and probably even a nice guy (gal?). At least you're latest post only had the initials "BS" in it as opposed to outright profanity and was only mildly insulting.
Now here is the description of LBLRTM, one of the "line by line" radiative transfer computer models used to give the climate sensitivity to CO2, that is listed at Wikipedia.
"Some important LBLRTM attributes are as follows:
The Voigt line shape is used at all atmospheric levels with an algorithm based on a linear combination of approximating functions;
It has been and continues to be extensively validated against atmospheric radiance spectra from the ultra-violet to the sub-millimeter;
It incorporates the self- and foreign-broadened water vapor continuum model, [Mlawer et al., 2003; MT_CKD_1.0] as well as continua for carbon dioxide, and for the collision induced bands of oxygen at 1600 cm-1 and nitrogen at 2350 cm-1.;
All parameters on the HITRAN line database are used including the pressure shift coefficient, the halfwidth temperature dependence and the coefficient for the self-broadening of water vapor;
A version of the Total Internal Partition Function (TIPS) program is used for the temperature dependence of the line intensities [Gamache at al., 1990];
The effects of line coupling are treated to second order with the coefficients for carbon dioxide in the 600 - 800 cm-1 region [Hoke et al., 1989] and first order with the coefficients for carbon dioxide in 1932, 2080, 2093, and 2193 Q-branch regions [Strow et. al, 1994];
Temperature dependent cross section data such as those available with the HITRAN database may be used to treat the absorption due to heavy molecules, e.g. the halocarbons;
An algorithm is implemented for the treatment of the variation of the Planck function within a vertically inhomogeneous layer as discussed in [Clough et al., 1992];
Its computational efficiency mitigates the computational burden of the line-by-line flux and cooling rate calculation [Clough et al., 1992], for example linear algebraic operations are used extensively in the computationally intensive parts of LBLRTM so that vectorization is particularly effective with a typical vectorized acceleration of 20;
FFT instrument function with a choice of 9 apodization functions;
Includes a realistic spectral sea surface emissivity model in the infrared [Masuda, et. al., 1988, Wu and Smith, 1997];
Input atmospheric profiles in either altitude or pressure coordinates;
Interfaces with other radiative transfer models (like RRTM), and as the forward model for inversion algorithms (like the Tropospheric Emission Spectrometer (TES) retrieval algorithm.
These attributes provide spectral radiance calculations with accuracies consistent with the measurements against which they are validated and with computational times that greatly facilitate the application of the line-by-line approach to current radiative transfer applications."
I hope we can both agree that this is hardly a "simple" calculation, but is in fact a very complex computer model that utilizes a set of sub-routines each containing complicated algorithms that each contain many assumptions and parameters.
Look I'm not here to pick nits, but it is highly inaccurate to say that the non-feedback CO2 climate sensitivity is a "simple" calculation using "basic" radiative physics.
Maybe the approximately 1 C figure generated by many of these models, and that is generally accepted, is correct but it is clearly not a matter of "fact" based on straight forward "calculation".
As I have said repeatedly I don't have a big problem with that figure because most people agree that a 1 degree increase in global average temp is not going to cause any catastrophe and would be hard to differentiate from natural variability.
I have a few questions in re: climate sensitivity for anyone who cares to address them.
#1. Isn't it true that the average climate sensitivity(either from GH heating or directly from the sun) is (thought to be) substantially lower than the one predicted to be operating now by the IPCC? (~ 0.25C/Wm-2 vs ~0.75C/Wm-2)
#2. Can't we also agree that cooler areas of Earth tend to more sensitive to increases in radiative forcing? Doesn't this also imply that a cold Earth is *generally* more sensitive to radiation, than a warmer one? Wouldn't this imply that as the Earth warms the marginal sensitivity to radiative forcing will decrease?
#3. Doesn't nature provide us with an example of a highly temperature insensitive system in the tropics, where the temperature doesn't move more than a couple of degrees C on a cloudy day as on a sunny day? Don't high moisture areas typically have lower maximum temperatures than drier ones?
Cheers, :)
I should make clear for 1 that by average temperature sensitivity, I mean, for instance, the total temperature increase due to the GHE divided by the total radiative forcing from the GHE?
Lance:
I don't have a big problem with that figure because most people agree that a 1 degree increase in global average temp
So you disagree that water vapor increases with temperature or that water vapor is a greenhouse gas. We have to be careful which day of the week we listen to so called "sceptics". Some days water vapor is a greenhouse gas, some days it isn't.
Shawn,
The climate sensitivity factor I usually see is 0.75 K W-1 m-2.
Yes, a warmer planet does react a bit more slowly to radiation. That's not enough to provide a measurable difference in the response to global warming, however, since we're only talking a few degrees K out of the globe's present 287 K mean global annual surface temperature.
Not sure what you mean by GHE. GreenHouse Effect?
Hi Barton,
Yes, sorry, GHE = greenhouse effect.
I agree that 0.75K/Wm^2 is commonly given as an output from the GCMs(climate models) as the current climate sensitivity, but I do not understand why there is such a discrepancy btw that number and the overall average for climate sensitivity. I should probably make clear what I mean by the overall average. I mean the total temperature change for all the greenhouse effect divided by the total energetic contribution per surface area.
For instance, Kiehl & Trenberth give the total back radiation from GH gases as 324Wm^-2 and since the textbook value for the GH temperature effect is ~34 deg. C, this gives us an approximate overall temperature sensitivity of ~0.105 deg. C/Wm^-2.
Thus, unless Kielh & Trenberth are *way* off, the current estimates (~.75 deg. C/Wm^-2) are also *way* above the overall average. Now, it is certainly *possible* for the current climate to be less efficient in dissipating heat compared to the overall average efficiency, but I can see no physical reason why this is so.
Cheers, :)
Chris O'Neil,
The hottest places on earth, deserts, have very low relative humidities in the atmosphere above them. Equitorial regions with high water vapor content are typically cooler than those with lower relative humidity. Water vapor makes clouds that reflect incoming solar radiation and precipitate water out of the system.
This is the reason that simple statements about water vapor being a positive feedback are problematic.
The hottest places on earth, deserts, have very low relative humidities in the atmosphere above them.
Annual average of maximum and minimum temperatures of Alice Springs, Australia (rainfall 279.1 mm, latitude -23.8 deg): 20.95 deg C.
Annual average of maximum and minimum temperatures of Gladstone, Australia (rainfall 877.7 mm, latitude -23.86 deg): 23.1 deg C.
Lance, please don't argue from ignorance. It makes you look like an idiot and a fool.
Chris O'Neil,
First of all you looked at two whole places and then you used average temperature not maximum temperature. The highest temperature ever measured on the surface of the earth was 136 Degrees F. measured in the Sahara desert.
The Sahara has one of the lowest relative humidities in the world, rarely exceeding 30%.
First of all you looked at two whole places
That's two more than you looked at.
and then you used average temperature not maximum temperature.
What's so special about maximum temperature? Have you ever wondered why deserts get cold at night?
And some of the coldest places on earth are also deserts, for instance the south pole. Hmmm ...
This is the reason that simple statements about water vapor being a positive feedback are problematic.
Yeah, yeah, we know, Lance, you're smart, climate scientists are dumb ...
Lance, As I said above, the line-by-line codes are complicated, not complex. The problem has a unique solution, and is not chaotic. The physics is known, the composition of the atmosphere is known. The methods for numerical solution are known. Many of the additions you mention are incorporating lower order effects for the purpose of adding accuracy to the digits down at the small end of the sig figs, or are for increasing the spectral resolution - current line by line codes are working the 0.1cm bandwidth range, a resolution necessary for newest-generation imaging applications.
The output can be and is compared to real world known absorption and transmission characteristics of the atmosphere. They are accurate enough to have been used successfully for a quarter century - in much less detailed and less accurate older versions - for successful design of military and civilian imaging sensors. They are used by the military to improve target detection and acquisition by spectral detection. They have been used and verified against sampling data for passive IR sensing of pollutant clouds. They have been successfully used in the antarctic to detect water vapor, by comparing spectra from sensors with Modtran spectra, with results comparable to and verified against those obtained by radiometer and radiosonde data. And on and on.
This is not cutting edge physics, Lance. This is a well used, well verified, well understood engineering solution based on well understood physics. If yo want to dispute the value of 3.7 w/m2 +- ~0.2 / 2xCO2 because it doesn't match your definition of simple, go ahead and beat your head against the wall on it. But this particular wall is awfully solid.
Lance says:
"I don't have a big problem with that figure because most people agree that a 1 degree increase in global average temp is not going to cause any catastrophe and would be hard to differentiate from natural variability."
So your willingness to accept that figure is based on its seeming lack of policy implications for you, and not on the science behind it?
Chris asked:What's so special about maximum temperature? Have you ever wondered why deserts get cold at night?
Just to butt in here, I would say that comparing max temps shows the *details* of the feedback process better. Knowing that the temperature of an area stays within a given range under conditions of high moisture during the day, but moves in a much larger range for dry areas seems like pretty good evidence that *past a certain point*, at least, water vapor is a *net* cooling force. I don't think anyone disputes that moist air holds heat better than dry air, so nighttime temps will obviously be higher in moist areas.
Cheers, :)
Posted by: Shawn | July 25, 2008 3:55 PM
Slapping my forehead in awe!
Lance has got some real competition here.
Lee,
"So your willingness to accept that figure is based on its seeming lack of policy implications for you, and not on the science behind it?"
That Co2 absorbs and re-emits IR radiation is a proven fact. If someone said that they had evidence that my next breath was going to raise the earth's temperature by 10 degrees Celsius I would vigorously dispute that claim, if they said my next breath was going to raise the earth's temperature by 1.2 x 10^-12 degrees I would question how they could determine that number but I probably wouldn't spend a lot of time arguing with them about it.
That is unless they were lobbying for a law that said I had to limit my activities to reduce my carbon dioxide output.
If people want to say that they know that a doubling of CO2 in the atmosphere will result in a less than one degree rise in global temperature for purely academic reasons I have some interest in the validity of their methodology and data but have no real reason to push my objections since it isn't my field of interest.
If they then seek to change the way the entire world uses the most plentiful form of energy available, fossil fuels, that is another thing entirely and it is going to elicit an entirely different level of response.
Extraordinary claims require extraordinary evidence especially when you are trying to tell everyone on the planet how to live their lives based on your claim.
So your willingness to accept that figure is based on its seeming lack of policy implications for you, and not on the science behind it?
Shorter Lance ... "yes, you're right".
Maybe he's not such a fucking lying dishonest shit after all.
But life would be easier to accept if he'd drop his pretentious bullshit facade in which he claims his personal genius trumps everything real scientists know about climate science.
If they then seek to change the way the entire world uses the most plentiful form of energy available, fossil fuels, that is another thing entirely and it is going to elicit an entirely different level of response.
In other words, lying about science. We understand, Lance, thanks again for your honesty.
no doubt that water vapor is probably the thorniest part of the model(s) as they currently stand. however, almost all analyses indicate positive feedback; and the few that indicate a negative feedback come up with a figure which is too weak to completely eliminate the positive forcing of CO2. (i can't remember any more who is "there is no warming" and who is "there is warming but it isn't co2" and who is "there is co2 warming, but less than mostly believed"; the maximum negative feedback value would at least be somewhat consistent with the latter position)
of course, this same truth knocks holy hell out of the "it's the cosmic rays nucleating clouds" family of "theories" (using the word very loosely).
Extraordinary claims require extraordinary evidence especially when you are trying to tell everyone on the planet how to live their lives based on your claim.
Lance doesn't quite seem to grasp that a quick look in the mirror would make it clear that his extraordinary claim ("physics PhD dropout knows more about climate science than the professionals in the field") requires extraordinary evidence, since he's trying to tell everyone on the planet that we should live our lives continuing to dump CO2 into the atmosphere in unfettered fashion ...
water vapor is a net cooling force.
No, it is a net damping force, it reduces diurnal (and seasonal) temp variation, but does not decrease mean temps.
You are also talking about straight air temps, which does not accurately represent total exogenous thermal load on an organism. Humidity also counts big time (as does radiant heat). A high humidity, high temp climate is much tougher to live in than a low humidity, high temp climate, all other things being equal.
To extend on Mr O'Neill's Alice Springs example given above. Max temps (and diurnal and seasonal variation) there are considerably higher than in Darwin, 1500 km to north, deep inside the steaming tropics. But guess which place has the lower average temp and is much more comfortable to live in? Hint: not the tropical one.
past a certain point, at least, water vapor is a net cooling force
I must remember that next time I'm in Queensland and it's 30 degrees C and 90% relative humidity.
Lance, re my post at 19, let me ask again:
"What exactly do you see here, Lance, that is inappropriately simplified for the problem as stated? Be specific."
Or, will you admit that the value for no-feedback sensitivity is ~1.1C for 2xCO2?
--
Now, lets go back to your post 134 in Open Thread 9 - where all this foolishenss started.
You also said there (among other foolishness):
[Lee]:"As an example - climate sensitivity determined from relationship of Milankovich forcing and glacial stade transitions, using a realistic value for the amount of solar forcing imposed on the planet due to orbital variation, and then comparing that to the temperature change, to determine climate sensitivity. This approach makes no assumptions about CO2 - and it arrives at a value of about 3C / 2xCO2.
[Lance]: Since "Bullcrap" is your politeness standard. I say Bullcrap back at ya. This technique assumes that first of all their "realistic" value is correct and that CO2 is responsible for anything they didn't guess correctly. That you find this convincing shows your bias.".
---
Back to teh present: I'll reiterate - bullcrap. Those analyses don't consider CO2. They are analyses of temperature change for a given change in SOLAR forcing. They look at temperature change in the ice core records for a delta-forcing due to calculated Milankovich orbital variations, and arrive at a value of ~3C temp increase for each ~4W/m2. Your dismissal of that on the grounds that they assume that "CO2 is responsible for anything they didn't guess correctly" once again simply shows that you don't know what the hell you are talking about. They didn't assign ANYTHING to CO2, they didn't calculate CO2 effects. They looked at delta forcing, not delta CO2.
---
But now:
We have a value you have admitted you can accept - even if you haven't admitted that the derivation is valid - of ~4w/m2 per 2xCO2. This leads, by straightforward radiative equilibration calculations, to a temperature change without feedbacks of about 1C.
We also have this independent calculation from the glacial transitions and Milankovich forcing. A delta forcing of ~4 W/m2 leads to a surface delta temperature of ~ 3C.
This 3C value (+- ~ 1C or so) is also supported by several other lines of evidence, some of which are independent of GCM results or assumptions about CO2, just as the glacial transition derivation is.
This is (a small part of) the evidence. You claim that you believe net feedback is negative, and thus 2xCO2 delta-forcing of ~4W/m2 results in a sensitivity of a small fraction of 1C.
How do you square that with the evidence that sensitivity to delta-forcing of ~4W/m2 leads to temperature increase of ~3C? How do you square this with your belief that net feedback MUST be negative? Well, other than by ignoring the evidence, of course.
Shawn,
Your extrapolation doesn't work. The figure isn't linear over the distance between a 287 K Earth and a 255 K Earth. If you're interested, there's an explanation of this in greater depth here:
When talking about H2O and sensitivity,forcing, etc. it should be remembered the three phases of H2o that we are dealing with, gas,liquid and solid. All three must be considered when dealing with H2O and it's effect on warming/cooling.
WotWot, I agree that water vapor has the effect of minimizing the daily temperature variation, so can we agree that water vapor acts to cool the surface during the day and warm it at night?
While your point about which locales are more liveable may be valid for the places you've chosen, it certainly isn't globally. Generally, less fluctuation in temperature is easier to deal with than more is(at least if world population centres are any guide). Further, everything is not equal, obviously, humid areas also have higher precipitation which is generally good for plant growth.
Barton, I read your link, but I must admit that I didn't quite see the relevance. They appear to be saying(in the terms of my argument) that we can't use the energetic increase of CO2 on its own, we must include the energetic increase of all the other feedbacks too. OK, that is fair enough, but can we at least agree on the numbers from Kiehl and Trenberth?
IF so, if we *could* calculate the energetic increases from the other feedbacks, do you agree that *that* temperature sensitivity should be of the same general size as the K&T numbers imply?
Cheers, :)
interesting. Our favorite incompetent data analyst and propagandist over at Watts Up With That is blocking contrary factual posts again. He has a post touting Back on CO2. I've posted the following twice, posting as IceAnomaly, which Anthony knows is me. Its being black holed.
---
""Why then is CO2 measured at only a few SPECIAL locations with procedures to EXCLUDE data?? Isn't this the ultimate cherry picking??"
Because what we are interested in is the contribution of CO2 to the entire atmosphere - not the local concentration at point sources or sinks. For understanding the amount of CO2 in the global atmosphere, it doesn't matter that the Gallo winery has a high local CO2 concentration in the fall - and yes, it does.
CO2 is well mixed in the atmosphere - we know that because we measure it at a couple dozen points on the earth, and also in specially equipped aircraft on long-haul flights, and we see the increase as a well-mixed process. Temperature is not well-mixed - it is highly heterogeneous, so we need many more sites to determine delta-temp over the entire surface.
Key point for the Beck stuff - the accuracy of the analytical technique can't fix sampling issues. Sampling near a gas-lit city, for example, is NOT going to give you the mixed-atmosphere value for CO2. It is going to give you the local point-source concentration, which is not what we are interested in."
Shawn:
can we at least agree on the numbers from Kiehl and Trenberth
Primo; If you'd bothered to read more than the abstract of K&T you'd have learned total LW forcing isn't the back LW radiation but the difference between surface LW radiation and TOA outgoing LW radiation. 155W/m^2.
Secundo; the 34C approximation for the net effect of the atmosphere, hydrosphere and cryospheres (greenhouse warming plus effects of changes to cloud and surface albedo) is relative to a blackbody with an albedo of 1.0 and no greenhouse effect. The Earth's actual albedo is ~0.7. That would mean without the greenhouse but with the same albedo, the Earth's temperature would be ~178.5K, a difference of ~108.5K.
Tertio; That would indicate a sensitivity of 108K/155Wm^2 or ~0.7K/Wm^-2.
The climate sensitivity factor I usually see is 0.75 K W-1 m-2.
I think you missed my point, perhaps I did not explain it properly. Simple temp measurement alone is not sufficient. While it is true that water vapour reduces temp during the day, it does not reduce the total thermal energy in the system, indeed it increases it (because the water vapour is storing the heat). Higher humidity at the same temp = greater thermal energy in the system.
Which was greeted with silence earlier on this thread.
A denialism troll greeted by silence. Whoopee doo.
A denialist troll who not only denies his own speciality but evolutionary biology, too.
Wow. He's very convincing.
We all know that NGS doesn't care a twit about the science, just his own extremely right-wing politics, but ... NGS ... you are aware that Spencer's track record regarding satellite data analysis is ABYSMAL? That he and Christy proclaimed global warming was disproven by the satellite record, only to be confronted with a very long string of analytical errors including a basic sign error in a multiplication? I would take anything this man says with a very, very large grain of salt given his track record. He jumps at the slimmest straws to pronounce "global warming is dead" and doesn't do sound analytical work. And, yes, I think the fact that he and Christy are both fundamentalist southern Baptists do cause the bias that blatantly LEAPS into their work.
3 ad-hom attacks so far, and I'm sure there are more in the works. This is how I know something has really hit the mark.
3 ad-hom attacks so far, and I'm sure there are more in the works. This is how I know something has really hit the mark.
I think when you use coarse language, you forfeit the argument. You also forfeit the argument when you classify those who disagree with you as morons.
So if a creationist is a moron, and you point out that the creationist is a moron, evolutionary biology is false.
Apparently NGS's brilliant logic has come from some sort of right-wing science denialism cookbook.
BTW, Spencer's creationism is pertinent to his scientific credibility, and pointing out that he is one is not an ad hom attack.
Also Spencer's abysmal past track record in his specialty, temperature reconstruction from satellite data, is pertinent to his "holy grail" argument which is based on - you guessed it - analysis of satellite data.
Pointing out this is not an ad hom.
nags,the most important of part of that Spencer screed is the last couple paragraphs, where he says (I paraphrase) ' my model cant explain the last century, but I will assume my model is correct and everyone else's is incorrect, invoke the unexplained, and make a handwaving but utterly unsupported appeal: "Couldn't most of this global warming simply be part of a natural cycle?" ".'
His description of what he did is also wrong on its face:
"(1) the change in temperature with time of the climate system is equal to (2) a net heating or cooling term plus (3) a feedback term representing the climate sensitivity. In fact, if I know the climate sensitivity (a coefficient in the feedback term) then I can make just as good an estimate of global warming with this one equation as can a state-of-the-art, multi-million dollar climate model running on a supercomputer.
I created such a simple model in an Excel spreadsheet. In the following graph we see a climate sensitivity chart for a model forced with only radiative forcing (representing, for instance, changing amounts of low cloud cover letting variable amounts of sunlight in)."
This is absurd. To be able to track short term (90 day!) variations in temps, his net heating or cooling term needs to model varying time constants of various parts of the earth system. His statement about his simple equation being able to do as well as the GCMs, is only true for equilibrium sensitivity, but he is not dealing with equilibrium sensitivity. He is dealing with 90 day averages of forcing - his model can ntt be predicting real world results, because he is comparing instantaneous changes in forcing, with equilibrium delta temp. This is just wierd. More relevant, his description of his 'simple' model running on excel, does not include any place for radiative compartmentalization, and yet he then goes on to describe varying results from different sources of forcing. Better yet, his description assigns a net cooling to evaporation - which implies that he is ignoring the net positive forcing effect of the increased water vapor.
So let's summarize the denialist creed regarding models ...
1. A dozen or so independently developed GCMs, based on well-known physics, blah blah blah, are all wrong. Very wrong. Worthless. Crap.
2. Spencer's fiddling in Excel, which fails at hindcasting, doesn't include relevant physics, has resulted in a wonderful model overturning most everything we know of climate science, and also happens to prove the earth is flat and the moon made of green cheese.
Fair summary?
Some weird secret stuff I saw on a conservative web site, while reading a climate inactivist essay.
I'm sure it's due to natural variation. Or intelligent design.
I looked at Kane's link. Daponte apparently thinks it was unethical for the Lancet team to gather information on deaths in a wartime environment, but not unethical for other researchers to do this.
She added no new argument that I could see to the debates people have had here in the past few years. She also chooses a very slanted way to compare numbers which is apparently designed to make IBC's figures seem more compatible with the UNDP toll and less compatible with Lancet 1, though in reality Lancet 1 and UNDP gave the same violent death toll for the period they had in common (if you use the midpoint figure.) To make IBC's number seem closer to the UNDP figure, she averages over different time periods--if she has used the same time period then the UNDP figure is 3 times higher than IBC, though to be fair UNDP doesn't distinguish between civilian and combatant. (I am being more fair than she is.) To make Lancet1 seem to be in disagreement with UNDP she includes total excess deaths in the Lancet1 figure, not just violent deaths.
I was confused by what she said about the prewar death toll. At first it seemed like she was saying that it was much higher than the two Lancet papers claimed, and then she seemed to say, no, it was possibly lower.
This is depressing. I get the impression this is yet another hatchet job. If one merely set out the numbers, you'd get IBC at the low end, IFHS survey next (about double IBC), Lancet1 and UNDP in virtual agreement at IBC times three, and L2 with the ORB survey (unmentioned) at the high end. But Daponte wanted to say it was IBC with IFHS and the UNDP numbers in one category, with L1 and L2 in another and she reached this conclusion through careful painstaking obfuscation.
What's up with Watts Up ? This goes right off the Godwin scale (or is it some attempt at self parody ?)
they seem to be experiencing some collective Nazi persecution fantasy.
"Shawn,
Primo; If you'd bothered to read more than the abstract of K&T you'd have learned total LW forcing isn't the back LW radiation but the difference between surface LW radiation and TOA outgoing LW radiation. 155W/m^2.
Secundo; the 34C approximation for the net effect of the atmosphere, hydrosphere and cryospheres (greenhouse warming plus effects of changes to cloud and surface albedo) is relative to a blackbody with an albedo of 1.0 and no greenhouse effect. The Earth's actual albedo is ~0.7. That would mean without the greenhouse but with the same albedo, the Earth's temperature would be ~178.5K, a difference of ~108.5K.
Tertio; That would indicate a sensitivity of 108K/155Wm^2 or ~0.7K/Wm^-2."
Luminous, Thank you for the correction in Primo. I was unaware that the forcing numbers were for top of atmosphere numbers(I am still a bit new at this). However, for secundo I don't know where you get your albedo numbers from. Wikipedia lists Earth's (I assume mean)albedo as 0.367. The Encyclopedia of Earth lists the albedo of the Earth and atmosphere as 30%.
OTOH, a cloudy sky has much higher albedo, is this where your 0.7 comes from? This would be in line with your 155W number- it is for cloudy skies?
IAC, I don't follow the derivation of the 178.5K number, would you mind describing it a bit for me?
WotWot,
"I think you missed my point, perhaps I did not explain it properly. Simple temp measurement alone is not sufficient. While it is true that water vapour reduces temp during the day, it does not reduce the total thermal energy in the system, indeed it increases it (because the water vapour is storing the heat). Higher humidity at the same temp = greater thermal energy in the system"
I agree with this, depending on how we define "the system", but my point(which I probably didn't make clear) was about surface temps(which are generally what we are concerned about). Clearly, water in all its forms is better for storing heat than land(IOW it dissipates slower). However, when it gets *extremely* hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
Cheers, :)
so this being an open thread and all....
do australians really drink
Fosters?
I appreciate Donald Johnson's comments. I still hope that we will hear from sod, as well as other Lancet aficionados. I still hope that Tim will give us a Lancet-only thread at some point.
Donald writes: "This is depressing. I get the impression this is yet another hatchet job." But what is your theory as to why? It is fine to assume that I am crazy, that Spagat argues in bad faith and so on about all the other Lancet "denialists." (Actually, it is wrong, but ignore that debate for now.) But here we have Daponte who lost her job under Bush I because she insisted on providing Iraqi casualty estimates that were higher than the Administration wanted. Do you really believe that she would write a "hatchet job?" Why would she do that?
Can't we just start by assuming that she wrote what she wrote because she believes it? Can we also agree that she is an expert on the topic?
By the way, I am still hoping for feedback from Donald (or anyone else) about this post.
Re: #65...
Not a single Australian I know would even consider drinking Fosters. In fact, I doubt that there are many Aussie blokes at all who would even grace Fosters with the name 'beer'.
It's possibly the worst fermented swill available commercially in the country!
nags,the most important of part of that Spencer screed is the last couple paragraphs, where he says (I paraphrase) ' my ...
I think the most important part is Fig 5. Do you think it is logical from that graphic to use all points to compute climate sensitivity? Or does it deserve further analysis?
do australians really drink Fosters?
Not on your life, sunshine.
What we have to do is put it in a different bottle, slap a shiny gold label and bottle cap on it, and call it Crown Lager. Then we drink it.
nags, please tell us who exactly is using the slope of the oceanic 90-day tropospheric temperature change against 90-day emission anomaly (I assume it is anomaly - Spencer labels it 'extra energy lost to space for reflected solar plus emitted infrared') - who is using it to compute climate sensitivity?
What he is measuring - if anything - in those short term 'steep' excursions is the time constant of direct tropospheric warming to direct solar forcing averaged over the 90-day short term. This might be useful to verify the radiative transfer calculations, but it is not climate sensitivity, not by any definition I've ever heard of.
And then in his model, what Spencer is calling 'feedback' in that analysis is NOT what we've been referring to as feedback. It is the change in radiative output as direct response to radiative input. This is - if anything - the 'no-feedback' response to changes in solar radiative input.
IW, what Spencer is doing in that screed is comparing some features of the time constant of short-term temp changes in the earth's atmosphere to some short-term features a no feed-back simple model, and trying to claim this tells us something about climate sensitivity.
So, no, nags. I don't think figure 5, or anything in that article, tells us anything at all about climate sensitivity.
Tamino has made one background post on Spencer's claims, and among other things makes the same point Lee does, that Spencer's not using "feedback" in the way it's typically used in climate science (though he points out there's nothing wrong with the usage, as long as you understand how he's using it).
Tamino says he'll follow up with a post specifically shredding addressing Spencer's claims soon. From tidbits in his background post, I suspect that his take on it will be similar to Lee's ("What he is measuring - if anything - in those short term 'steep' excursions is the time constant of direct tropospheric warming to direct solar forcing averaged over the 90-day short term."), with the same conclusion, i.e. he's not measuring climate sensitivity despite his claims.
Tamino will do it with rigor, not that this seems to impress NGS in the least, judging from past history...
Shawn:
However, when it gets extremely hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
You're confusing evaporation with the greenhouse effect.
Lee, I think you'll find out more about what Spencer is doing at this link:
So, NGS, you're not by any chance hanging your hat on Spencer's work because it fits with his and your right-wing political views, right?
I mean, you're drooling over Spencer's work due to your belief that he's objectively right, and all the other climate scientists are wrong, and they're ignoring him because they're all pinkos or worse, right?
Lee, I think you'll find out more about what Spencer is doing at this link
as if we don't know enough already.
"#72Shawn:
However, when it gets extremely hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
You're confusing evaporation with the greenhouse effect."
I don't really think so, I am just trying to explore the relationship btw the two processes as the temperature changes.
ALso, for whoever is interested, in re #47, it seems that the 33C number for total GH warming is *inclusive* of albedo effects. See wikipedia's page on black body for an example of the calculation.
Cheers, :)
nags,
Check out Tamino's takedown of Spencer's analysis. Spencer is diagnosing the instantaneous response to an instantaneous change in forcing, NOT the sensitivity as it is generally known. HE is missing all processes with time constants longer than, at most, 90 days, and then is claiming that this short temr response is diagnostic off the entire process.
In other news, Lance seems to have lost interest in this thread.
However, when it gets extremely hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
You're confusing evaporation with the greenhouse effect.
I don't really think so, I am just trying to explore the relationship btw the two processes as the temperature changes.
"just trying to explore the relationship.."
Yes, "exploring the relationship" is one of those advanced scientific thingies.
I mentioned this article on Iraqi mortality to Tim a little while ago. I think it would lead to an interesting thread at Deltoid. My comments here.
Summary: Yale researcher thinks Lancet estimates stink.
Summary: Yale researcher thinks Lancet estimates stink.
so does a sloppy comparison.
it is a very one sided approach. i ll try to comment more later.
Lee,
"The radiative balance idea applies OVER TIME. If there is an imbalance, the planet will warm or cool until it gets back into balance, where incoming and outgoing energy are equal."
Look, you are going around in circles now. This is where I applied the (radiant energy in) > (radiant energy out) statement. And for the steady-state situation you are trying to imply it is a correct statement. There is no such equilibrium "radiative balance".
Also I'd like you to please tell me where this claimed "calculation" for the non-feedback CO2 sensitivity can be found.
You have danced around this point since the beginning. Below is a recounting of your posts on the subject.
"The coupled GCM models do NOT HAVE ANY ASSIGNED CO2 SENSITIVITY!! CO2 sensitivity comes OUt of the models."
So much for your claim of a simple "calculation that everyone agrees on".
"This is basic radiative physics - that you don't know this indicts your knowledge base."
Again if it is so basic please stop making insulting noises and just produce the damn thing.
"The calculated forcing for a doubling of CO2 is about 3.7 w/m2. The value is accepted by nearly everyone, even most of the staunchest denialists. Try this link."
Here is the entirety of the information at the link you provided.
6.3.1 Carbon Dioxide
IPCC (1990) and the SAR used a radiative forcing of 4.37 Wm-2 for a doubling of CO2 calculated with a simplified expression. Since then several studies, including some using GCMs (Mitchell and Johns, 1997; Ramaswamy and Chen, 1997b; Hansen et al., 1998), have calculated a lower radiative forcing due to CO2 (Pinnock et al., 1995; Roehl et al., 1995; Myhre and Stordal, 1997; Myhre et al., 1998b; Jain et al., 2000). The newer estimates of radiative forcing due to a doubling of CO2 are between 3.5 and 4.1 Wm-2 with the relevant species and various overlaps between greenhouse gases included. The lower forcing in the cited newer studies is due to an accounting of the stratospheric temperature adjustment which was not properly taken into account in the simplified expression used in IPCC (1990) and the SAR (Myhre et al., 1998b). In Myhre et al. (1998b) and Jain et al. (2000), the short-wave forcing due to CO2 is also included, an effect not taken into account in the SAR. The short-wave effect results in a negative forcing contribution for the surface-troposphere system owing to the extra absorption due to CO2 in the stratosphere; however, this effect is relatively small compared to the total radiative forcing (< 5%).
The new best estimate based on the published results for the radiative forcing due to a doubling of CO2 is 3.7 Wm-2, which is a reduction of 15% compared to the SAR. The forcing since pre-industrial times in the SAR was estimated to be 1.56 Wm-2; this is now altered to 1.46 Wm-2 in accordance with the discussion above. The overall decrease of about 6% (from 1.56 to 1.46) accounts for the above effect and also accounts for the increase in CO2 concentration since the time period considered in the SAR (the latter effect, by itself, yields an increase in the forcing of about 10%).
While an updating of the simplified expressions to account for the stratospheric adjustment becomes necessary for radiative forcing estimates, it is noted that GCM simulations of CO2-induced climate effects already account for this physical effect implicitly (see also Chapter 9). In some climate studies, the sum of the non-CO2 well-mixed greenhouse gases forcing is represented by that due to an equivalent amount of CO2. Because the CO2 forcing in the SAR was higher than the new estimate, the use of the equivalent CO2 concept would underestimate the impact of the non-CO2 well-mixed gases, if the IPCC values of radiative forcing were used in the scaling operation.
Note it says that they started with a value "calculated with a simplified expression" in 1990 but of course doesn't actually cite the calculation and decided later, based on other techniques and studies, that it was too high.
Then they used various methods including ones using GCMs and now have several different values that vary according to various assumptions despite your "everyone agrees" remarks.
So much for a simple calculation to obtain CO2 climate sensitivity.
When I pinned you down and asked again for this calculation that everyone agrees on you posted this.
"and here, Lance, is a listing of radiative transfer codes used to make this kind of calculation:
http://en.wikipedia.org/wiki/Listofatmosphericradiativetransfer_codes
And here is Modtran - have fun:
http://geosci.uchicago.edu/~archer/cgimodels/radiation.html"
Uh, codes? The first link is botched and goes no where, and the second goes to modtran, a computer model that magically spits out the ansewr if you give it input parameters.
Again neither of these is a "simple calculation" based on "basic radiative physics".
After some discussion of thermodynamics you posted.
"But there are only two issues in play. 1. What does the increase in back-scattered radiative energy from the increased CO2 do to the energy retention time in the system and therefore the total energy retained in the system. This is a 'simple' 2D radiative transfer calculation of a new state given a simple addition of a greenhouse gas to the current observed state. 2. How much warming is necessary to come into radiative balance with the increased energy in the atmosphere. This is a 'simple' gray body calculation."
Note that you again assert that there exists a "simple" 2-D radiative transfer calculation for the climate sensitivity to a doubling of CO2.
OK then where the hell is it?!
Most recently, in your last post you say, "First, it isn't a simple linear calculation - it is an integration across the atmospheric column of radiative transfer, using the known input of the sun, the known temperature and composition of the atmosphere, and the known absorption, emission, and collision properties of those gasses."
For the last time I ask you to produce this "simple 2-D calculation" (that you now call an "integration")not a link to some website, but the actual calculation.
Lance, stop being such a vapid idiot, please.
""The calculated forcing for a doubling of CO2 is about 3.7 w/m2. The value is accepted by nearly everyone, even most of the staunchest denialists. Try this link."
Here is the entirety of the information at the link you provided."
Lance, re-read the text you posted here. See this:
"have calculated a lower radiative forcing due to CO2 (Pinnock et al., 1995; Roehl et al., 1995; Myhre and Stordal, 1997; Myhre et al., 1998b; Jain et al., 2000). The newer estimates of radiative forcing due to a doubling of CO2 are between 3.5 and 4.1 Wm-2 with the relevant species and various overlaps between greenhouse gases included."
See the names and date in parentheses, Lance? Those are called "citations." They give you the information necessary to go GET THE DAMN PAPERS AND READ THEM!!!!
---
"Then they used various methods including ones using GCMs and now have several different values that vary according to various assumptions despite your "everyone agrees" remarks."
Christ almighty...
The estimates range between 3.5 and 4.1 W/m2. That isn't plus-or-minus standard error, Lance. That is the entire range, between most extreme results. The most likely value of 3.7 reflects the range and distribution of those estimates, none of which are away from that value by more than - 0.2W/m2 or +0.4W/m2, . You are arguing that this shows some kind of practical disagreement in the forcing estimate? Even the lowest of those estimates yields a sensitivity of 1C, and the highest about 1.3C or so. You think this is something you can use to dispute the value I cited of 1.1, in an argument where you are claiming that the 'real' value is some fraction of that?? Get fucking real.
More important, lose the intentional ignorance as debate tactic, Lance. It is intellectually lazy and dishonest. You claim to be a physicist. I gave you a link to a summary of the knowledge, with CITATIONS TO THE PRIMARY FUCKING PAPERS from which the summary was derived and the values taken - and you sit there and complain that I didn't show you the calculations? In my field - biology - I learned how to use a citation to track down a paper about 3 weeks into my freshman year. Don't they teach that to you physicists?
Lance, try separating the run together words in the above url with underlines.
Miranda Devine has an article in today's smh about World Youth Day, and how great and beautiful and "radiant" Catholic youth is compared to other kinds of people who are "aggressive secularists", and full of "nihilism", "rancid negativity" etc.
But the bit that I want to focus on is:
"Living in an era when faith and reason, art and mathematics, were inextricably linked, Renaissance artists would regard modern relativistic notions of beauty as ludicrous."
Now look: I read about the whole Alan Sokal thing, and I think its great that the spotlight was put on various humanities departments to lift their game, especially when it comes to drawing analogies to the weirdness in contemporary science when trying to make a philosophical point or comment on society or life.
But it seems to be increasingly common for people - especially in the blogosphere - to smear science and smear their ideological opponents as being pomo's, or relativists - without ever articulating exactly what they find so objectionable in their opponents argument. Its just a one word insult.
I think that is pathetic.
Like many ideas about the world, (e.g. evolution, climate change, psychotherapy, economic rationalism), postmodern theory can be validly challenged and criticised. But a lot of it makes sense, or has some intellectual value, or is at least thought provoking in a good way, and to use a label like 'pomo' or 'relativist' as a one word insult is anti-intellectual.
It reminds me of how climate sceptics have successfully created a popular meme that there is something theological about climate change science. The whole religious metaphor to characterise the majority of people who are moving in accordance with mainstream science and politics infuriates me. What a joke.
I am moodily expecting to see an increasing use of terms like 'relativist' and 'post-modernist' in pitiful ideological attacks against science and to score cheap ideological points from now on.
Not to mention also, Lance, that the broken link you disparage is obviously a wikipedia link, and is obviously to something called "List of atmospheric radiative transfer codes."
Links get broken by blogs - its fairly common. Intelligent people who see a wikipedia link to a list of radiative transfer codes, and are asking about such radiative transfer calculations, would freaking FIND a wikipedia page that is a list of radiative transfer codes. Failure to find that page is clear willful ignorance.
Not to mention further that you completely ignored the part - in the post you are specifically responding to - about the simplification in this particular calculation.
And you wonder why people get frustrated with you.
Upon reflection, I have decided that this statement from my earlier post:
"the 2nd law has no bearing on the radiative balance condition, which is a simple statement of the first law, applied to a nonequilibrium steady state."
is incorrect. It's incorrect in a very interesting way - the 2nd law is actually used to derive a crucial part of the radiative balance condition ! The calculation of outward radiative flux, whether crude (Stefan-Boltzmann) or sophisticated (line-by-line radiative transfer codes) literally has the 2nd law built into it. Stefan-Boltzmann, Kirchoff's Law, and the Wien Displacement Law can all be (and originally were) derived from the 2nd Law.
Lance: you've probably taken at least one and probably more than one course in Statistical Mechanics. Did you study Linear Response Theory ? Climate sensitivity is exactly analogous to LRT. As long as the change in the forcing is small compared to the overall forcing, you can calculate the response to a change in forcing from the equilibrium properties of the system. The Kubo Formula for electrical conductivity works for real electrons in real circuits, even though real electrical currents are (necessarily) far from equilibrium.
You OK Lee?
In my last post replace: "As long as the change in the forcing is small compared to the overall forcing"
with "as long as the change in the magnitude of the driving force..." or something equivalent. "Radiative forcing", by definition, is of course already a differential quantity - it's the result of the change, not the thing that is changed.
where you see the pointer:> Broken links
It's the software (which mangles underscores)
That's a feature, and explained right above the big empty box with the line around it at the end of the thread. See:
Comments: (you may use HTML tags or markdown for style)
"markdown" links to here:
http://daringfireball.net/projects/markdown/dingus
That explains why typing underscores into URLs with this software breaks them.
Our host only had to explain this to me about three times that I can recall (no doubt after cleaning up messes I left til patience wore thin at my lack of reading comprehension).
Clues. So common, so hard to see. Get one today.
I'm worried, too. He underreacted to Lance's lying, dishonest, repetitive act.
It's been ages since we were treated to a Fumento piece. Has Mikey retired?
Robert P.,
While I didn't cover linear response theory in my studies of thermodynamics it did come up in a solid state quantum physics course.
As I recall it involved the time dependent response to an oscillating system to a small perturbation described using the Hamiltonian.
I'm not sure I understand its application to climate sensitivity.
Global Warming: Has the Climate Sensitivity Holy Grail Been Found?
http://www.weatherquestions.com/Climate-Sensitivity-Holy-Grail.htm
"This article addresses new satellite and modeling evidence that previous satellite diagnoses of high climate sensitivity--which directly translate into predictions of dangerous levels of global warming--contain a large spurious bias. It is shown that those exaggerated estimates were the result of faulty assumptions regarding clouds when analyzing variations in average global temperature and average reflected sunlight off of the Earth. "
Lee,
The studies that are cited in the IPCC link you provided do not use a "calculation" based on "basic radiative" physics, simple or otherwise, as you claim. I know; I have read at least the abstract of all of them. Most use computer climate models and some just make corrections to the accepted estimate based on other factors such as short wave interactions with the stratosphere (Myhre et al. (1998b) and Jain et al. (2000)).
You can't provide a "simple calculation" for non-feedback CO2 climate sensitivity that "everyone agrees on" because one does not exist.
Screaming profanity laced insults changes that fact not one wit.
These non-feedback Co2 climate sensitivity estimates are based on highly simplified assumptions. As I said earlier since the figure is usually estimated at around 1 degree C for a doubling of CO2 I don't generally argue about it, but to assert that it is a "fact" is to overstate the confidence that should be placed in such a number.
Why do the Deniers infest the Scientific American comments section to such a degree? The S.A is pretty decent at reporting the issue. Is it the high profile that the magazine occupies among the popular science publications?
Lance - BS.
Look at the Collins et al 2006, for example,for a table listing the line-by-line codes they evaluated. Look at the wikipedia page I cited for a larger listing of line-by-line radiative transfer codes.
Those are not 'simple' calculations in the sense that you can write them down and solve for "x." They are very large and complicated calculations - but not complex calculations. They are simple in that they arrive at unique answers, based on known physics and known atmosphere profiles. Your 'complexity' criticisms of the climate models do not apply to these line by line codes. Versions of them are embedded in the climate models, but they are not the climate models, and they can be and are run independent of the models.
The "correcting" papers you dismiss are in fact runs of the line-by-line codes, with additional terms added for lower-order effects. Your continuing refusal to acknowledge the existence of these codes is getting absurd, Lance. Your refusal to acknowledge the general acceptance of these values is absurd as well. Spencer accepts a 2xCO2 forcing value near 1C - he thinks negative feedback reduces the with-feedback response to a much smaller value. Hell, even Monckton accepts it, although he doesn't seem to realize he does. He starts with a value in this range before he confuses forcing with temperature and arbitrarily divides the forcing value by three because he doesn't see trop trop warming.
--
And yes, the non-feedback CO2 warming values are based on highly simplifying assumption. That highly-simplifying assumption is that THERE IS NO FEEDBACK. That is why it is the non-feedback value. This is definitional.
The problem then simplifies to:
1. Given 2xCO2, what is the change in radiation transfer characteristics. The line by line codes provides that answer. It adds 3.5 - 4.1 w/m2 of forcing.
2. Given 3.5-4.1 w/m2 of additional forcing and no change in the gray-body characteristics of the earth other than that caused directly by the added CO2 (because there is no feedback, so nothing else changes) how much must the planet surface and atmosphere heat up to radiate an additional 3.5 - 4.1 w/m2, to balance that additional forcing. The answer is 1C - 1.3C at the surface.
What exactly do you see here, Lance, that is inappropriately simplified for the problem as stated? Be specific.
Lee,
You're obviously an intelligent person and probably even a nice guy (gal?). At least you're latest post only had the initials "BS" in it as opposed to outright profanity and was only mildly insulting.
Now here is the description of LBLRTM, one of the "line by line" radiative transfer computer models used to give the climate sensitivity to CO2, that is listed at Wikipedia.
"Some important LBLRTM attributes are as follows:
The Voigt line shape is used at all atmospheric levels with an algorithm based on a linear combination of approximating functions;
It has been and continues to be extensively validated against atmospheric radiance spectra from the ultra-violet to the sub-millimeter;
It incorporates the self- and foreign-broadened water vapor continuum model, [Mlawer et al., 2003; MT_CKD_1.0] as well as continua for carbon dioxide, and for the collision induced bands of oxygen at 1600 cm-1 and nitrogen at 2350 cm-1.;
All parameters on the HITRAN line database are used including the pressure shift coefficient, the halfwidth temperature dependence and the coefficient for the self-broadening of water vapor;
A version of the Total Internal Partition Function (TIPS) program is used for the temperature dependence of the line intensities [Gamache at al., 1990];
The effects of line coupling are treated to second order with the coefficients for carbon dioxide in the 600 - 800 cm-1 region [Hoke et al., 1989] and first order with the coefficients for carbon dioxide in 1932, 2080, 2093, and 2193 Q-branch regions [Strow et. al, 1994];
Temperature dependent cross section data such as those available with the HITRAN database may be used to treat the absorption due to heavy molecules, e.g. the halocarbons;
An algorithm is implemented for the treatment of the variation of the Planck function within a vertically inhomogeneous layer as discussed in [Clough et al., 1992];
Its computational efficiency mitigates the computational burden of the line-by-line flux and cooling rate calculation [Clough et al., 1992], for example linear algebraic operations are used extensively in the computationally intensive parts of LBLRTM so that vectorization is particularly effective with a typical vectorized acceleration of 20;
FFT instrument function with a choice of 9 apodization functions;
Includes a realistic spectral sea surface emissivity model in the infrared [Masuda, et. al., 1988, Wu and Smith, 1997];
Input atmospheric profiles in either altitude or pressure coordinates;
Interfaces with other radiative transfer models (like RRTM), and as the forward model for inversion algorithms (like the Tropospheric Emission Spectrometer (TES) retrieval algorithm.
These attributes provide spectral radiance calculations with accuracies consistent with the measurements against which they are validated and with computational times that greatly facilitate the application of the line-by-line approach to current radiative transfer applications."
I hope we can both agree that this is hardly a "simple" calculation, but is in fact a very complex computer model that utilizes a set of sub-routines each containing complicated algorithms that each contain many assumptions and parameters.
Look I'm not here to pick nits, but it is highly inaccurate to say that the non-feedback CO2 climate sensitivity is a "simple" calculation using "basic" radiative physics.
Maybe the approximately 1 C figure generated by many of these models, and that is generally accepted, is correct but it is clearly not a matter of "fact" based on straight forward "calculation".
As I have said repeatedly I don't have a big problem with that figure because most people agree that a 1 degree increase in global average temp is not going to cause any catastrophe and would be hard to differentiate from natural variability.
I have a few questions in re: climate sensitivity for anyone who cares to address them.
#1. Isn't it true that the average climate sensitivity(either from GH heating or directly from the sun) is (thought to be) substantially lower than the one predicted to be operating now by the IPCC? (~ 0.25C/Wm-2 vs ~0.75C/Wm-2)
#2. Can't we also agree that cooler areas of Earth tend to more sensitive to increases in radiative forcing? Doesn't this also imply that a cold Earth is *generally* more sensitive to radiation, than a warmer one? Wouldn't this imply that as the Earth warms the marginal sensitivity to radiative forcing will decrease?
#3. Doesn't nature provide us with an example of a highly temperature insensitive system in the tropics, where the temperature doesn't move more than a couple of degrees C on a cloudy day as on a sunny day? Don't high moisture areas typically have lower maximum temperatures than drier ones?
Cheers, :)
I should make clear for 1 that by average temperature sensitivity, I mean, for instance, the total temperature increase due to the GHE divided by the total radiative forcing from the GHE?
Lance:
So you disagree that water vapor increases with temperature or that water vapor is a greenhouse gas. We have to be careful which day of the week we listen to so called "sceptics". Some days water vapor is a greenhouse gas, some days it isn't.
Shawn,
The climate sensitivity factor I usually see is 0.75 K W-1 m-2.
Yes, a warmer planet does react a bit more slowly to radiation. That's not enough to provide a measurable difference in the response to global warming, however, since we're only talking a few degrees K out of the globe's present 287 K mean global annual surface temperature.
Not sure what you mean by GHE. GreenHouse Effect?
Hi Barton,
Yes, sorry, GHE = greenhouse effect.
I agree that 0.75K/Wm^2 is commonly given as an output from the GCMs(climate models) as the current climate sensitivity, but I do not understand why there is such a discrepancy btw that number and the overall average for climate sensitivity. I should probably make clear what I mean by the overall average. I mean the total temperature change for all the greenhouse effect divided by the total energetic contribution per surface area.
For instance, Kiehl & Trenberth give the total back radiation from GH gases as 324Wm^-2 and since the textbook value for the GH temperature effect is ~34 deg. C, this gives us an approximate overall temperature sensitivity of ~0.105 deg. C/Wm^-2.
http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
Thus, unless Kielh & Trenberth are *way* off, the current estimates (~.75 deg. C/Wm^-2) are also *way* above the overall average. Now, it is certainly *possible* for the current climate to be less efficient in dissipating heat compared to the overall average efficiency, but I can see no physical reason why this is so.
Cheers, :)
Chris O'Neil,
The hottest places on earth, deserts, have very low relative humidities in the atmosphere above them. Equitorial regions with high water vapor content are typically cooler than those with lower relative humidity. Water vapor makes clouds that reflect incoming solar radiation and precipitate water out of the system.
This is the reason that simple statements about water vapor being a positive feedback are problematic.
Annual average of maximum and minimum temperatures of Alice Springs, Australia (rainfall 279.1 mm, latitude -23.8 deg): 20.95 deg C.
Annual average of maximum and minimum temperatures of Gladstone, Australia (rainfall 877.7 mm, latitude -23.86 deg): 23.1 deg C.
Lance, please don't argue from ignorance. It makes you look like an idiot and a fool.
Chris O'Neil,
First of all you looked at two whole places and then you used average temperature not maximum temperature. The highest temperature ever measured on the surface of the earth was 136 Degrees F. measured in the Sahara desert.
The Sahara has one of the lowest relative humidities in the world, rarely exceeding 30%.
That's two more than you looked at.
What's so special about maximum temperature? Have you ever wondered why deserts get cold at night?
And some of the coldest places on earth are also deserts, for instance the south pole. Hmmm ...
Yeah, yeah, we know, Lance, you're smart, climate scientists are dumb ...
Lance, As I said above, the line-by-line codes are complicated, not complex. The problem has a unique solution, and is not chaotic. The physics is known, the composition of the atmosphere is known. The methods for numerical solution are known. Many of the additions you mention are incorporating lower order effects for the purpose of adding accuracy to the digits down at the small end of the sig figs, or are for increasing the spectral resolution - current line by line codes are working the 0.1cm bandwidth range, a resolution necessary for newest-generation imaging applications.
The output can be and is compared to real world known absorption and transmission characteristics of the atmosphere. They are accurate enough to have been used successfully for a quarter century - in much less detailed and less accurate older versions - for successful design of military and civilian imaging sensors. They are used by the military to improve target detection and acquisition by spectral detection. They have been used and verified against sampling data for passive IR sensing of pollutant clouds. They have been successfully used in the antarctic to detect water vapor, by comparing spectra from sensors with Modtran spectra, with results comparable to and verified against those obtained by radiometer and radiosonde data. And on and on.
This is not cutting edge physics, Lance. This is a well used, well verified, well understood engineering solution based on well understood physics. If yo want to dispute the value of 3.7 w/m2 +- ~0.2 / 2xCO2 because it doesn't match your definition of simple, go ahead and beat your head against the wall on it. But this particular wall is awfully solid.
Lance says:
"I don't have a big problem with that figure because most people agree that a 1 degree increase in global average temp is not going to cause any catastrophe and would be hard to differentiate from natural variability."
So your willingness to accept that figure is based on its seeming lack of policy implications for you, and not on the science behind it?
Chris asked:What's so special about maximum temperature? Have you ever wondered why deserts get cold at night?
Just to butt in here, I would say that comparing max temps shows the *details* of the feedback process better. Knowing that the temperature of an area stays within a given range under conditions of high moisture during the day, but moves in a much larger range for dry areas seems like pretty good evidence that *past a certain point*, at least, water vapor is a *net* cooling force. I don't think anyone disputes that moist air holds heat better than dry air, so nighttime temps will obviously be higher in moist areas.
Cheers, :)
Posted by: Shawn | July 25, 2008 3:55 PM
Slapping my forehead in awe!
Lance has got some real competition here.
Lee,
"So your willingness to accept that figure is based on its seeming lack of policy implications for you, and not on the science behind it?"
That Co2 absorbs and re-emits IR radiation is a proven fact. If someone said that they had evidence that my next breath was going to raise the earth's temperature by 10 degrees Celsius I would vigorously dispute that claim, if they said my next breath was going to raise the earth's temperature by 1.2 x 10^-12 degrees I would question how they could determine that number but I probably wouldn't spend a lot of time arguing with them about it.
That is unless they were lobbying for a law that said I had to limit my activities to reduce my carbon dioxide output.
If people want to say that they know that a doubling of CO2 in the atmosphere will result in a less than one degree rise in global temperature for purely academic reasons I have some interest in the validity of their methodology and data but have no real reason to push my objections since it isn't my field of interest.
If they then seek to change the way the entire world uses the most plentiful form of energy available, fossil fuels, that is another thing entirely and it is going to elicit an entirely different level of response.
Extraordinary claims require extraordinary evidence especially when you are trying to tell everyone on the planet how to live their lives based on your claim.
Shorter Lance ... "yes, you're right".
Maybe he's not such a fucking lying dishonest shit after all.
But life would be easier to accept if he'd drop his pretentious bullshit facade in which he claims his personal genius trumps everything real scientists know about climate science.
In other words, lying about science. We understand, Lance, thanks again for your honesty.
no doubt that water vapor is probably the thorniest part of the model(s) as they currently stand. however, almost all analyses indicate positive feedback; and the few that indicate a negative feedback come up with a figure which is too weak to completely eliminate the positive forcing of CO2. (i can't remember any more who is "there is no warming" and who is "there is warming but it isn't co2" and who is "there is co2 warming, but less than mostly believed"; the maximum negative feedback value would at least be somewhat consistent with the latter position)
of course, this same truth knocks holy hell out of the "it's the cosmic rays nucleating clouds" family of "theories" (using the word very loosely).
Lance doesn't quite seem to grasp that a quick look in the mirror would make it clear that his extraordinary claim ("physics PhD dropout knows more about climate science than the professionals in the field") requires extraordinary evidence, since he's trying to tell everyone on the planet that we should live our lives continuing to dump CO2 into the atmosphere in unfettered fashion ...
water vapor is a net cooling force.
No, it is a net damping force, it reduces diurnal (and seasonal) temp variation, but does not decrease mean temps.
You are also talking about straight air temps, which does not accurately represent total exogenous thermal load on an organism. Humidity also counts big time (as does radiant heat). A high humidity, high temp climate is much tougher to live in than a low humidity, high temp climate, all other things being equal.
To extend on Mr O'Neill's Alice Springs example given above. Max temps (and diurnal and seasonal variation) there are considerably higher than in Darwin, 1500 km to north, deep inside the steaming tropics. But guess which place has the lower average temp and is much more comfortable to live in? Hint: not the tropical one.
I must remember that next time I'm in Queensland and it's 30 degrees C and 90% relative humidity.
Lance, re my post at 19, let me ask again:
"What exactly do you see here, Lance, that is inappropriately simplified for the problem as stated? Be specific."
Or, will you admit that the value for no-feedback sensitivity is ~1.1C for 2xCO2?
--
Now, lets go back to your post 134 in Open Thread 9 - where all this foolishenss started.
You also said there (among other foolishness):
[Lee]:"As an example - climate sensitivity determined from relationship of Milankovich forcing and glacial stade transitions, using a realistic value for the amount of solar forcing imposed on the planet due to orbital variation, and then comparing that to the temperature change, to determine climate sensitivity. This approach makes no assumptions about CO2 - and it arrives at a value of about 3C / 2xCO2.
[Lance]: Since "Bullcrap" is your politeness standard. I say Bullcrap back at ya. This technique assumes that first of all their "realistic" value is correct and that CO2 is responsible for anything they didn't guess correctly. That you find this convincing shows your bias.".
---
Back to teh present: I'll reiterate - bullcrap. Those analyses don't consider CO2. They are analyses of temperature change for a given change in SOLAR forcing. They look at temperature change in the ice core records for a delta-forcing due to calculated Milankovich orbital variations, and arrive at a value of ~3C temp increase for each ~4W/m2. Your dismissal of that on the grounds that they assume that "CO2 is responsible for anything they didn't guess correctly" once again simply shows that you don't know what the hell you are talking about. They didn't assign ANYTHING to CO2, they didn't calculate CO2 effects. They looked at delta forcing, not delta CO2.
---
But now:
We have a value you have admitted you can accept - even if you haven't admitted that the derivation is valid - of ~4w/m2 per 2xCO2. This leads, by straightforward radiative equilibration calculations, to a temperature change without feedbacks of about 1C.
We also have this independent calculation from the glacial transitions and Milankovich forcing. A delta forcing of ~4 W/m2 leads to a surface delta temperature of ~ 3C.
This 3C value (+- ~ 1C or so) is also supported by several other lines of evidence, some of which are independent of GCM results or assumptions about CO2, just as the glacial transition derivation is.
This is (a small part of) the evidence. You claim that you believe net feedback is negative, and thus 2xCO2 delta-forcing of ~4W/m2 results in a sensitivity of a small fraction of 1C.
How do you square that with the evidence that sensitivity to delta-forcing of ~4W/m2 leads to temperature increase of ~3C? How do you square this with your belief that net feedback MUST be negative? Well, other than by ignoring the evidence, of course.
Shawn,
Your extrapolation doesn't work. The figure isn't linear over the distance between a 287 K Earth and a 255 K Earth. If you're interested, there's an explanation of this in greater depth here:
Climate Sensitivity
When talking about H2O and sensitivity,forcing, etc. it should be remembered the three phases of H2o that we are dealing with, gas,liquid and solid. All three must be considered when dealing with H2O and it's effect on warming/cooling.
WotWot, I agree that water vapor has the effect of minimizing the daily temperature variation, so can we agree that water vapor acts to cool the surface during the day and warm it at night?
While your point about which locales are more liveable may be valid for the places you've chosen, it certainly isn't globally. Generally, less fluctuation in temperature is easier to deal with than more is(at least if world population centres are any guide). Further, everything is not equal, obviously, humid areas also have higher precipitation which is generally good for plant growth.
Barton, I read your link, but I must admit that I didn't quite see the relevance. They appear to be saying(in the terms of my argument) that we can't use the energetic increase of CO2 on its own, we must include the energetic increase of all the other feedbacks too. OK, that is fair enough, but can we at least agree on the numbers from Kiehl and Trenberth?
IF so, if we *could* calculate the energetic increases from the other feedbacks, do you agree that *that* temperature sensitivity should be of the same general size as the K&T numbers imply?
Cheers, :)
interesting. Our favorite incompetent data analyst and propagandist over at Watts Up With That is blocking contrary factual posts again. He has a post touting Back on CO2. I've posted the following twice, posting as IceAnomaly, which Anthony knows is me. Its being black holed.
---
""Why then is CO2 measured at only a few SPECIAL locations with procedures to EXCLUDE data?? Isn't this the ultimate cherry picking??"
Because what we are interested in is the contribution of CO2 to the entire atmosphere - not the local concentration at point sources or sinks. For understanding the amount of CO2 in the global atmosphere, it doesn't matter that the Gallo winery has a high local CO2 concentration in the fall - and yes, it does.
CO2 is well mixed in the atmosphere - we know that because we measure it at a couple dozen points on the earth, and also in specially equipped aircraft on long-haul flights, and we see the increase as a well-mixed process. Temperature is not well-mixed - it is highly heterogeneous, so we need many more sites to determine delta-temp over the entire surface.
Key point for the Beck stuff - the accuracy of the analytical technique can't fix sampling issues. Sampling near a gas-lit city, for example, is NOT going to give you the mixed-atmosphere value for CO2. It is going to give you the local point-source concentration, which is not what we are interested in."
Shawn:
We can agree on their numbers but not your conclusions from them.
Shawn,
Primo; If you'd bothered to read more than the abstract of K&T you'd have learned total LW forcing isn't the back LW radiation but the difference between surface LW radiation and TOA outgoing LW radiation. 155W/m^2.
Secundo; the 34C approximation for the net effect of the atmosphere, hydrosphere and cryospheres (greenhouse warming plus effects of changes to cloud and surface albedo) is relative to a blackbody with an albedo of 1.0 and no greenhouse effect. The Earth's actual albedo is ~0.7. That would mean without the greenhouse but with the same albedo, the Earth's temperature would be ~178.5K, a difference of ~108.5K.
Tertio; That would indicate a sensitivity of 108K/155Wm^2 or ~0.7K/Wm^-2.
Please see:
Global Warming: Has the Climate Sensitivity Holy Grail Been Found? http://www.weatherquestions.com/Climate-Sensitivity-Holy-Grail.htm
Which was greeted with silence earlier on this thread.
If you need a break from the dismal questions of climatology, this bit on auditing will perhaps be amusing:
http://appraisersforum.com/showthread.php?t=141764
Shawn
I think you missed my point, perhaps I did not explain it properly. Simple temp measurement alone is not sufficient. While it is true that water vapour reduces temp during the day, it does not reduce the total thermal energy in the system, indeed it increases it (because the water vapour is storing the heat). Higher humidity at the same temp = greater thermal energy in the system.
A denialism troll greeted by silence. Whoopee doo.
A denialist troll who not only denies his own speciality but evolutionary biology, too.
Wow. He's very convincing.
We all know that NGS doesn't care a twit about the science, just his own extremely right-wing politics, but ... NGS ... you are aware that Spencer's track record regarding satellite data analysis is ABYSMAL? That he and Christy proclaimed global warming was disproven by the satellite record, only to be confronted with a very long string of analytical errors including a basic sign error in a multiplication? I would take anything this man says with a very, very large grain of salt given his track record. He jumps at the slimmest straws to pronounce "global warming is dead" and doesn't do sound analytical work. And, yes, I think the fact that he and Christy are both fundamentalist southern Baptists do cause the bias that blatantly LEAPS into their work.
3 ad-hom attacks so far, and I'm sure there are more in the works. This is how I know something has really hit the mark.
Yeah, creationists and 9/11 denialists say the same thing, to wit:
So if a creationist is a moron, and you point out that the creationist is a moron, evolutionary biology is false.
Apparently NGS's brilliant logic has come from some sort of right-wing science denialism cookbook.
BTW, Spencer's creationism is pertinent to his scientific credibility, and pointing out that he is one is not an ad hom attack.
Also Spencer's abysmal past track record in his specialty, temperature reconstruction from satellite data, is pertinent to his "holy grail" argument which is based on - you guessed it - analysis of satellite data.
Pointing out this is not an ad hom.
nags,the most important of part of that Spencer screed is the last couple paragraphs, where he says (I paraphrase) ' my model cant explain the last century, but I will assume my model is correct and everyone else's is incorrect, invoke the unexplained, and make a handwaving but utterly unsupported appeal: "Couldn't most of this global warming simply be part of a natural cycle?" ".'
His description of what he did is also wrong on its face:
"(1) the change in temperature with time of the climate system is equal to (2) a net heating or cooling term plus (3) a feedback term representing the climate sensitivity. In fact, if I know the climate sensitivity (a coefficient in the feedback term) then I can make just as good an estimate of global warming with this one equation as can a state-of-the-art, multi-million dollar climate model running on a supercomputer.
I created such a simple model in an Excel spreadsheet. In the following graph we see a climate sensitivity chart for a model forced with only radiative forcing (representing, for instance, changing amounts of low cloud cover letting variable amounts of sunlight in)."
This is absurd. To be able to track short term (90 day!) variations in temps, his net heating or cooling term needs to model varying time constants of various parts of the earth system. His statement about his simple equation being able to do as well as the GCMs, is only true for equilibrium sensitivity, but he is not dealing with equilibrium sensitivity. He is dealing with 90 day averages of forcing - his model can ntt be predicting real world results, because he is comparing instantaneous changes in forcing, with equilibrium delta temp. This is just wierd. More relevant, his description of his 'simple' model running on excel, does not include any place for radiative compartmentalization, and yet he then goes on to describe varying results from different sources of forcing. Better yet, his description assigns a net cooling to evaporation - which implies that he is ignoring the net positive forcing effect of the increased water vapor.
"It's crap" is not an ad hominem argument.
Internal forcing ... that's the ticket ... yeah ... internal forcing ...
So let's summarize the denialist creed regarding models ...
1. A dozen or so independently developed GCMs, based on well-known physics, blah blah blah, are all wrong. Very wrong. Worthless. Crap.
2. Spencer's fiddling in Excel, which fails at hindcasting, doesn't include relevant physics, has resulted in a wonderful model overturning most everything we know of climate science, and also happens to prove the earth is flat and the moon made of green cheese.
Fair summary?
Some weird secret stuff I saw on a conservative web site, while reading a climate inactivist essay.
I'm sure it's due to natural variation. Or intelligent design.
I looked at Kane's link. Daponte apparently thinks it was unethical for the Lancet team to gather information on deaths in a wartime environment, but not unethical for other researchers to do this.
She added no new argument that I could see to the debates people have had here in the past few years. She also chooses a very slanted way to compare numbers which is apparently designed to make IBC's figures seem more compatible with the UNDP toll and less compatible with Lancet 1, though in reality Lancet 1 and UNDP gave the same violent death toll for the period they had in common (if you use the midpoint figure.) To make IBC's number seem closer to the UNDP figure, she averages over different time periods--if she has used the same time period then the UNDP figure is 3 times higher than IBC, though to be fair UNDP doesn't distinguish between civilian and combatant. (I am being more fair than she is.) To make Lancet1 seem to be in disagreement with UNDP she includes total excess deaths in the Lancet1 figure, not just violent deaths.
I was confused by what she said about the prewar death toll. At first it seemed like she was saying that it was much higher than the two Lancet papers claimed, and then she seemed to say, no, it was possibly lower.
This is depressing. I get the impression this is yet another hatchet job. If one merely set out the numbers, you'd get IBC at the low end, IFHS survey next (about double IBC), Lancet1 and UNDP in virtual agreement at IBC times three, and L2 with the ORB survey (unmentioned) at the high end. But Daponte wanted to say it was IBC with IFHS and the UNDP numbers in one category, with L1 and L2 in another and she reached this conclusion through careful painstaking obfuscation.
What's up with Watts Up ? This goes right off the Godwin scale (or is it some attempt at self parody ?)
http://wattsupwiththat.wordpress.com/2008/07/27/hey-kids-be-a-climate-c…
they seem to be experiencing some collective Nazi persecution fantasy.
"Shawn,
Primo; If you'd bothered to read more than the abstract of K&T you'd have learned total LW forcing isn't the back LW radiation but the difference between surface LW radiation and TOA outgoing LW radiation. 155W/m^2.
Secundo; the 34C approximation for the net effect of the atmosphere, hydrosphere and cryospheres (greenhouse warming plus effects of changes to cloud and surface albedo) is relative to a blackbody with an albedo of 1.0 and no greenhouse effect. The Earth's actual albedo is ~0.7. That would mean without the greenhouse but with the same albedo, the Earth's temperature would be ~178.5K, a difference of ~108.5K.
Tertio; That would indicate a sensitivity of 108K/155Wm^2 or ~0.7K/Wm^-2."
Luminous, Thank you for the correction in Primo. I was unaware that the forcing numbers were for top of atmosphere numbers(I am still a bit new at this). However, for secundo I don't know where you get your albedo numbers from. Wikipedia lists Earth's (I assume mean)albedo as 0.367. The Encyclopedia of Earth lists the albedo of the Earth and atmosphere as 30%.
http://www.eoearth.org/article/Albedo
OTOH, a cloudy sky has much higher albedo, is this where your 0.7 comes from? This would be in line with your 155W number- it is for cloudy skies?
IAC, I don't follow the derivation of the 178.5K number, would you mind describing it a bit for me?
WotWot,
"I think you missed my point, perhaps I did not explain it properly. Simple temp measurement alone is not sufficient. While it is true that water vapour reduces temp during the day, it does not reduce the total thermal energy in the system, indeed it increases it (because the water vapour is storing the heat). Higher humidity at the same temp = greater thermal energy in the system"
I agree with this, depending on how we define "the system", but my point(which I probably didn't make clear) was about surface temps(which are generally what we are concerned about). Clearly, water in all its forms is better for storing heat than land(IOW it dissipates slower). However, when it gets *extremely* hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
Cheers, :)
so this being an open thread and all....
do australians really drink
Fosters?
I appreciate Donald Johnson's comments. I still hope that we will hear from sod, as well as other Lancet aficionados. I still hope that Tim will give us a Lancet-only thread at some point.
Donald writes: "This is depressing. I get the impression this is yet another hatchet job." But what is your theory as to why? It is fine to assume that I am crazy, that Spagat argues in bad faith and so on about all the other Lancet "denialists." (Actually, it is wrong, but ignore that debate for now.) But here we have Daponte who lost her job under Bush I because she insisted on providing Iraqi casualty estimates that were higher than the Administration wanted. Do you really believe that she would write a "hatchet job?" Why would she do that?
Can't we just start by assuming that she wrote what she wrote because she believes it? Can we also agree that she is an expert on the topic?
By the way, I am still hoping for feedback from Donald (or anyone else) about this post.
Re: #65...
Not a single Australian I know would even consider drinking Fosters. In fact, I doubt that there are many Aussie blokes at all who would even grace Fosters with the name 'beer'.
It's possibly the worst fermented swill available commercially in the country!
I think the most important part is Fig 5. Do you think it is logical from that graphic to use all points to compute climate sensitivity? Or does it deserve further analysis?
do australians really drink Fosters?
Not on your life, sunshine.
What we have to do is put it in a different bottle, slap a shiny gold label and bottle cap on it, and call it Crown Lager. Then we drink it.
nags, please tell us who exactly is using the slope of the oceanic 90-day tropospheric temperature change against 90-day emission anomaly (I assume it is anomaly - Spencer labels it 'extra energy lost to space for reflected solar plus emitted infrared') - who is using it to compute climate sensitivity?
What he is measuring - if anything - in those short term 'steep' excursions is the time constant of direct tropospheric warming to direct solar forcing averaged over the 90-day short term. This might be useful to verify the radiative transfer calculations, but it is not climate sensitivity, not by any definition I've ever heard of.
And then in his model, what Spencer is calling 'feedback' in that analysis is NOT what we've been referring to as feedback. It is the change in radiative output as direct response to radiative input. This is - if anything - the 'no-feedback' response to changes in solar radiative input.
IW, what Spencer is doing in that screed is comparing some features of the time constant of short-term temp changes in the earth's atmosphere to some short-term features a no feed-back simple model, and trying to claim this tells us something about climate sensitivity.
So, no, nags. I don't think figure 5, or anything in that article, tells us anything at all about climate sensitivity.
Tamino has made one background post on Spencer's claims, and among other things makes the same point Lee does, that Spencer's not using "feedback" in the way it's typically used in climate science (though he points out there's nothing wrong with the usage, as long as you understand how he's using it).
Tamino says he'll follow up with a post specifically shredding addressing Spencer's claims soon. From tidbits in his background post, I suspect that his take on it will be similar to Lee's ("What he is measuring - if anything - in those short term 'steep' excursions is the time constant of direct tropospheric warming to direct solar forcing averaged over the 90-day short term."), with the same conclusion, i.e. he's not measuring climate sensitivity despite his claims.
Tamino will do it with rigor, not that this seems to impress NGS in the least, judging from past history...
Shawn:
You're confusing evaporation with the greenhouse effect.
Lee, I think you'll find out more about what Spencer is doing at this link:
http://climatesci.org/wp-content/uploads/spencer-ppt.pdf
He references Forster & Taylor (2006).
So, NGS, you're not by any chance hanging your hat on Spencer's work because it fits with his and your right-wing political views, right?
I mean, you're drooling over Spencer's work due to your belief that he's objectively right, and all the other climate scientists are wrong, and they're ignoring him because they're all pinkos or worse, right?
as if we don't know enough already.
"#72Shawn:
However, when it gets extremely hot, WV movements take most of that excess heat away from the ground, which is why we get higher maximum temperatures in drier climates.
You're confusing evaporation with the greenhouse effect."
I don't really think so, I am just trying to explore the relationship btw the two processes as the temperature changes.
ALso, for whoever is interested, in re #47, it seems that the 33C number for total GH warming is *inclusive* of albedo effects. See wikipedia's page on black body for an example of the calculation.
Cheers, :)
nags,
Check out Tamino's takedown of Spencer's analysis. Spencer is diagnosing the instantaneous response to an instantaneous change in forcing, NOT the sensitivity as it is generally known. HE is missing all processes with time constants longer than, at most, 90 days, and then is claiming that this short temr response is diagnostic off the entire process.
In other news, Lance seems to have lost interest in this thread.
"just trying to explore the relationship.."
Yes, "exploring the relationship" is one of those advanced scientific thingies.