Major Errors Apparent in Climate Model Evaporation Estimates

Guest essay by Richard J. Petschauer, Senior Member IEEE

The physics of evaporation has complications related to what happens at the water / air interface such as wind speed and wave action. However if these factors remain constant, how evaporation changes with temperature and humidity can be estimated with well-known equations based on how water vapor pressure varies with temperature. For example, at a typical ocean temperature of 17 C, it should increase about 6.5% / C if the water vapor increases to maintain relative humidity, that the climate models indicate. If the surface air tracks the water within ± 2 C, the rate varies from 6.2% to 6.9% / C. Data over oceans by Wentz et, al (2007) report values of about 6% / C.

But the complex computer climate models show averages of only about 2.5% / C. There are no claims of reduced wind speeds or wave action or increased relative humidity to explain this. However many papers on the subject claim that the available energy is limiting evaporation in these models. But physics theory tells us that the latent energy for evaporation comes from the temperature of the water itself. The latent heat leaving the surface cools it and deposits heat in the atmosphere, part of which escapes to outer space. This combination causes negative feedback. The reduced net energy from increased CO2 still warms the surface, but this energy can’t be separated from what aids the final increased evaporation. A 6% / C increase applies to the water after the negative feedback is complete. Do the climate models ignore this cooling and feedback process?

A typical paper on this subject is one by O’Gorman and Schneider (2008) that defines this energy balance constraint that is supported by many other climate model references. Their equations (8) and (9) correctly show that an increase in latent heat transfer from evaporation must equal a reduction in the net surface radiation heat loss, assuming the loss from convection plus sensible heat and the net solar surface absorption all remain constant. However, this cannot provide a solution.

Let E = the latent heat loss from the surface due to evaporation, G the outward surface radiation and D the downwelling radiation from the atmosphere to the surface. Net surface radiation loss = G – D.

For a reduced radiation heat loss,

D E = D D – D G (1)

However, the developers of the climate models seem to be confusing independent and dependent variables. Evaporation is the driver or forcing agent controlled by the physics at the surface, and G and D must respond to a change in it. If the surface temperature rises, the additional latent heat lost at the surface will cause an offsetting decrease in the temperature and thus G. And the latent heat deposited in the atmosphere warms it and increases the downwelling radiation, D (and the outgoing radiation). We now have a feedback process at work. Equation (1) can only be used as a check after a correct solution is found to new values of E, D and G after the feedback process is complete. It appears there is a serious error in how climate models estimate evaporation as indicated in the rest of this paper.

We have developed a dynamic three level energy balance model (reference 1) with updates as described later that can be used for a number of forcings and feedbacks including the response to changes in evaporation and the cooling of the surface and the warming of the atmosphere.

The results are shown on the next page. No energy constraints of evaporations are seen.

As shown in Figure A1 in the appendix, we define S as the net incoming solar flux after albedo, A the absorption of the net solar flux by the atmosphere, G the surface radiation, W the surface radiation through the atmospheric window, H the convection from the surface, E the latent heat from surface evaporation (both H and E transfer heat to the atmosphere), U the atmosphere upward outgoing longwave radiation, and D the atmosphere downwelling longwave radiation to the surface. For this estimate the following values are fixed: S = 235; A = 67; H = 24. These and the baseline values shown in Table 1 are from Kiehl and Trenberth (1997) with average cloudy conditions of 60% coverage net considering overlaps.

From eqs (4 to 8) on the next page, Table 1 compares the baseline case with three having large forcings of 10 Wm-2 at the top of the atmosphere. One case has no evaporation changes, while two have rate changes of 6% and 10% / C. D T is calculated from the changes in G from the baseline.

The In minus Out fluxes are equal at all three levels for all the cases with each parameter used at least twice. No problem in finding the energy to support evaporation; the surface gave up some by cooling and the down radiation, D increased. Note that the increase in E is based on the final reduced temperature rise. In all cases D E = D D – D G, measured from the baseline.

Table 1 – With large TOA forcings no energy constraints on evaporation changes.

Increase in E follows that estimated from temperature change and the specified change %.

For example in case 3, E » Eo + r D T Eo = 78 + 0.06 x 1.57 x 78 = 85.34 » 85.40 shown.

Ignoring the drop in D T, from the value of 2.70 the increase in E to 85.40 is only 3.5% / C.

 TOA forcing & evap change D T – C G W E U D 1) 0 & 0 (Baseline) 0 390 40 78 195 324 2) 10 Wm-2 & 0 % / C 2.70 404.85 41.52 78 193.48 338.85 3) 10 Wm-2 & 6% / C 1.57 398.57 40.88 85.40 194.12 339.97 4) 10 Wm-2 & 10% / C 1.23 396.69 40.69 87.63 194.31 340.32

In – Out: Case 1

TOA = S – W + U = 235 – 40 – 195 = 0

Atmosphere = A + G – W + H + E – U – D = 67 + 390 – 40 + 24 + 78 – 195 – 324 = 0

Surface = S – A + D – G – H – E = 235 – 67 + 324 – 390 – 24 – 78 = 0

In – Out: Case 2

TOA = S – W + U = 235 – 41.52 – 193.48 = 0

Atm = A + G – W + H + E – U – = 67 + 404.85 – 41.52 + 24 + 78 – 193.48 – 338.85 = 0

Surface = S – A + D – G – H – E = 235 – 67 + 338.85 – 404.85 – 24 – 78 = 0

In – Out: Case 3

TOA = S – W + U = 235 – 40.88 – 194.12 = 0

Atm = A + G – W + H + E – U – D = 67 + 398.57 – 40.88 + 24 + 85.4 – 194.12 – 339.97 = 0

Surface = S – A + D – G – H – E = 235 – 67 + 339.97 – 398.57 – 24 – 85.4 = 0

In – Out: Case 4

TOA = S – W + U = 235 – 40.69 – 194.31 = 0

Atm = A + G – W + H + E – U – D = 67 + 396.69 – 40.69 + 24 + 87.63 – 194.31 – 340.32 = 0

Surface = S – A + D – G – H – E = 235 – 67 + 340.32 – 396.69 – 24 – 87.63 = 0

Note the increase in E follows that estimated from the temperature change and the specified change %. For example in case 4, E » Eo+ r D T Eo = 78 + 0.10 x 1.23 x 78 = 87.59 » 87.63.

No energy constraint is seen and all energy balances at the three levels are maintained.

The details of the calculations for the above table follow. The basic equations for energy balance at all three levels are from our paper, reference (1). For balance at the top of the atmosphere,

S = k (A + H + E) + k Ga + G (1 – a) (2)

Refer to Figure A1 in the appendix. S is the net incoming solar after albedo, k is the fraction of the total heat absorbed by the atmosphere that is radiated upward (here 0.3757), and a is the fraction of the surface longwave radiation absorbed by the atmosphere including clouds (here 0.8974).

Solving for G,

G = [S – k (A + H + E)] / (1 – a + ak) (3)

If we start with balance at the surface and again solve for G, we get the same result that also forces balance at the atmosphere.

To determine the feedback factor for E, add to it the increase caused by a 1 C surface temperature change and convert the change in G to a temperature change. For a 6% increase of 78, E becomes 82.68, the new value of G is 386.0014 Wm-2, down from 390, and provides a temperature change of –0.741 C which equals the feedback factor, the temperature change before additional feedback. With no other feedbacks, the feedback multiplier is M = 1 / (1 – F); here we get M = 0.5744. The temperature change of –0.741 would produce another change of -0.741 x –0.741 or +0.549, followed by (–0.741)3 or –0.406 then (–0.741)4 or +0.301, etc which sum converges to a final temperature drop –0.4256 C which also equals M x F or -0.741 x 0.5744.

As an alternate to using a feedback factor and a way to check it, the above equation for G can be modified to allow E, the evaporation rate, to vary with the change of surface temperature implied from the change in G, the surface radiation. Then the solution for the new surface radiation is,

G » [S – k (A + H) – k (E0 – r E G0 Tr)] / (1 – a + ak + k r E0Tr) (4)

Where r = the fractional rate of change / C of surface evaporation, E0 the initial evaporation, G0 the initial surface radiation, and Tr the temperature change rate factor at G0 which is T0 / (4 G0) with T0 the initial surface temperature. At 288 K or 15 C, Tr = 0.1846 C / W m-2. Here we get M = 0.581.

(Equation 3 is more accurate. The two values of M are very close for smaller forcings)

The final value of evaporation latent heat,

Ef = E0 + r TrE0 (G – G0) (5)

The temperature change uses the inverse of the Stefan-Boltzmann equation for G and G0.

The final value of W, Wf = G (1 – a) (6)

The final value of U, Uf = S – Wf (7)

The final value of D, Df = G + A + H + Ef – S (8)

The parameter a is the fraction of the surface longwave radiation absorbed by the atmosphere. Here it is 0.8974 or 1 – W0 / G0, whereW0 = 40, the amount through the atmospheric window and G0 = 390. The value k is the fraction of the total heat radiated from the atmosphere that is upward outgoing radiation. So k = U / (U + D). For our baseline k = 195 / (195 + 324) = 0.3757. To impose a forcing R at the TOA, k = (195 – R) / (195 – R + 324). Unless a or k is the value being perturbed, the equations above require the baseline values for a and k. For other values of a and k, partial derivatives are needed as described in the appendix.

It appears the climate models are grossly underestimating the negative feedback from latent heat transfer. For case 3 in the table above, the feedback multiplier of 1.57 / 2.70 = 0.581 implies a feedback factor for a change in evaporation of 6% / C of –0.720 C / C. This corresponds to the IPCC value for water vapor of 1.8 Wm-2 / C divided by their value of l of 3.2 to give a feedback factor of +0.562 C / C.

If we use the IPCC value of only 2.5% / C for evaporation changes, our feedback factor of –0.720 drops to –0.308. This compares fairly closely to the IPCC lapse rate feedback factor of –0.262 C / C, based on their value of –0.84 Wm-2 / C.

If one just wanted the feedback factor, equation (2) is more accurate. As described above, for a 6 % evaporation change rate, it gives a feedback factor of –0.741

The IPCC has a positive cloud feedback of 0.69 Wm-2 / C with a very large range. But it is not based on reduced clouds with warming, but as a residual of the amount of warming the models can not explain by the other feedbacks (Soden and Held (2006), p 3357, paragraph 2). So this is not a true estimate of cloud feedback. Eliminating it and replacing the lapse rate feedback with our evaporation feedback cuts the IPCC feedback multiplier from 2.48 down to 0.910.

The three level energy balance model used here is dynamic since it handles balance simultaneously at all three levels: the planet, the atmosphere and the surface. With atmospheric CO2 content increasing very slowly, only about 0.54% per year, there is more than enough time for the normal weather systems to move and distribute the small additional heat across the globe as it always has done in the past. So a simple improved global energy balance should be adequate. Another benefit of the three level model is that it can also handle changes in downwelling radiations. For both increased CO2 and water vapor, besides decreasing outgoing radiation, they will also increase downwelling radiation since these emission levels will move down to warmer temperatures. Present models that must refer everything to the outgoing radiation at the top of the atmosphere have a problem with this.

The use of spectral radiance tools for the atmosphere in both outward and downwelling directions under clear and cloudy conditions can handle the effects of CO2 and the significant water vapor feedback, including its negative feedback component of absorbing incoming solar radiation. These tools, available to all, can greatly improve accuracy and replace the present complicated unreliable computer models which, besides overestimating climate sensitivity, have large ranges of uncertainty of about ± 50%.

Richard J. Petschauer

Email: rjpetsch@aol.com

References

2) Kiehl, J. T., and K. E. Trenberth (1997): Earth’s Annual Global Mean Energy Budget. Bull. Amer. Meteorol. Soc., 78: 197-208

3) Wentz, F. J., L. Ricciardulli, K. Hilburn and C. Mears (2007): How much more rain will global warming bring? Science, Vol 317, 13 July 2007, 233-235

4) Soden, B.J., and Held, I.M. (2006): An assessment of climate feedbacks in coupled ocean-atmosphere models. J. Clim.19: 3354–3360.

5) O’Gorman, P. A., and Schneider, T (2008): The Hydrological Cycle over a Wide Range of Climates Simulated with an Idealized GCM. Amer. Meteorol. Soc., 1 August 2008, 3815-2831

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Appendix

From Figure A1, the present balanced conditions before any perturbation changes are (all in W m-2):

S = 342 – 77 – 30 = 235; A = 67; H = 24; E = 78; G = 390; W = 40; a = (390 – W) / 390 » 0.8974

where W is the amount through the atmospheric window, and k = 195 / (195 + 324) » 0.3757.

From Figure A1 it can be seen that for balance of heat flux in and out at the TOA,

S = k (A + H + E) + kGa + G (1 – a) (A1)

Solving for G,

G = [S – k (A + H + E)] / (1 – a + ak) (A2)

With the above base value in equation (A1), G = G0 = 390 Wm-2 corresponding to a surface at 14.9853 C. To perturb any value, change it and calculate a new G and from that a temperature change.

To impose a forcing R at the TOA, k = (195 – R) / (195 – R + 324). Unless a or k is the value being perturbed, the equations above require the baseline values for a and k. For other values of these, partial derivatives as shown below

At the lower part of the atmosphere,

G/ E = G/ H = ∂G/A = –∂G/D = – k / (1 a + ak) (A3)

At the top of the atmosphere for longwave radiation only,

G/ U= (k – 1) / (1 a + ak) (A4)

For change in net solar, S, shortwave incoming radiation, the forcing is substantially larger than for longwave radiation:

From changes in the solar strength,

G/ S= (1 – kA / S) / (1 a + ak ) (A5)

From changes in albedo,

G/ S » 1 / (1 a + ak) (A6)

For changes in evaporation with the present value of k or a different one, equation (A3) is used to get a feedback factor. The present value of k assumes the division of changes in radiation leaving the atmosphere are in the same ratio as the present total values. This ends up with a smaller temperature change at the upward outgoing emission level than that of the downwelling level. Changing the ratio of U / D to (U / D) 0.75 results in equal temperature changes and increases k from 0.3757 to 0.4059. From forcing at the TOA from CO2 at a typical emission level of about 10 km, one would think that the upward emission level temperature would increase more than the lower level. This suggests a value of k greater than 0.4059 of about 0.42 to 0.43.

The value a is simply a function of the fraction of emission through the atmospheric window and the estimated net fractional cloud cover, Cc. For changes to be compatible with this baseline with 60% cloud cover for different cloud coverage,

a = 1 – 100 / 390 (1 – Cc) (A7)

This implies a clear sky atmospheric window of 100/390 or 25.6%. Based on spectral radiance runs with Hitran 2008, a closer value of 22.8% results. Then,

a = 1 – 0.228 (1 – Cc) (A8)

For 60% cloud coverage, a = 0.9086, up from 0.8974.

Changing k to 0.4059 and a to 0.9086, increases the evaporation feedback factor from = –0.741 to –0.765.

92 thoughts on “Major Errors Apparent in Climate Model Evaporation Estimates”

1. Mike Jonas says:

Thanks, Richard J. Petschauer. That’s a lot of maths to go through, and I haven’t done it yet, but you appear to be on the right track:

at a typical ocean temperature of 17 C, [evaporation] should increase about 6.5% / C “.

It seems reasonable to assume that precipitation would increase in line with evaporation:

Science 27 April 2012:Vol. 336 no. 6080 pp. 455-458 DOI: 10.1126/science.1212222
https://www.sciencemag.org/content/336/6080/455
We show that ocean salinity patterns express an identifiable fingerprint of an intensifying water cycle. Our 50-year observed global surface salinity changes, combined with changes from global climate models, present robust evidence of an intensified global water cycle at a rate of 8 ± 5% per degree of surface warming. This rate is double the response projected by current-generation climate models and suggests that a substantial (16 to 24%) intensification of the global water cycle will occur in a future 2° to 3° warmer world.“.

Confirmation by Dr Susan Wijffels on ABC (Australian Broadcasting Corporation) “Catalyst” program ..
http://www.abc.net.au/catalyst/stories/3796205.htm
We’re already starting to detect and see big changes in the extreme events. And we’ve only really warmed the Earth by 0.8 of a degree. If we were to warm the Earth by 3 or 4 degrees, the changes in the hydrological cycle could be near 30 percent. I mean, that’s just a huge change, and it’s very hard for us to imagine.

It seems extraordinary unreasonable to assume that precipitation could increase like that without there being a similar increase in evaporation.

2. jauntycyclist says:

given

Alberto ARRIBAS HERRANZ Met Office, UK Ensemble Forecasting Research Group says in a paper “In terms of model formulation, there are two main sources of uncertainty: first of all, only imperfect models are available, and second, the resolution of these models is limited. The place where both factors more clearly come together is in what is known as physical parameterizations (i.e. the representation of the effects of processes occurring at unresolved scales using comparatively simple deterministic functions of the resolved variables). In any of them, the value of a large number of empirical-adjustable parameters and thresholds present is somewhat arbitrary, either because of being based on incomplete physical knowledge of the process or because of having been tuned to give optimal results for a test case that is not necessarily representative of more general applications (Yang and Arrit 2002). ”
from
‘Analysis of the impact of a stochastic physics parameterization on the seasonal
forecasting of the North Atlantic Oscillation’
Alberto ARRIBAS HERRANZ Met Office, UK Ensemble Forecasting Research Group

then its open knowledge the problems with models but somehow all those caveats disappear when presenting science to the public or policy makers.

funnily enough oceanographers using a basic physics based model managed to recreate the effect of the sun in changing climate lol
” Using a physics-based climate model, the authors were able to test the response of the ocean to changes in the solar output and found similar results to the data. ”

http://www.reportingclimatescience.com/news-stories/article/sun-fingered-for-little-ice-age-say-researchers.html

Yeah, whatever.

Squealing little lukewarmers were given their chance. They blew it.

Evaporation rates wrong? This is news?

Evaporation is the primary way the atmosphere cools the oceans. How does the atmosphere cool? Radiative gases.

Just get over yourselves.

Sure, I am a nasty piece of work. That doesn’t stop me being right ;-)

“There are no good and bad people in the world. There are only ever and always the bad people, it’s just that some of them are on different sides.” – T Pratchett

An unending sea of evil, shallow in most places, but deeper, oh so much deeper in others……

I may be a monster, by I am MY monster.

(Anthony, I can take out Monckton, Willis and Dr. Brown, yah got anything or anyone else?*)

*I am always the smartest guy in the room.**

** Dependant on room size. Serving suggestion only. Results may vary.

4. slow to follow says:

FWIW – Swimming pool engineering has a good body of knowledge on the topic of heat transfer from open water by evaporative losses.

5. Old England says:

Interesting, and the effect of convection on the calculations is ?

6. Joe Born says:

Is conductive loss so low that Equation (1) can ignore it?

“And the latent heat deposited in the atmosphere warms it and increases the downwelling radiation.” Is that correct? I had thought increased heat would increase radiation only after it became sensible.

7. I understand this blog to support negative feedback from phase change in H2O at the surface and radiation of the energy from the top of the atmosphere.

The author observes that models that support global warming incorrectly posit an energy constraint on evaporation.

I conclude that this is what forces them to introduce positive feedback to make their model work.

I think my conclusion follows from the data and discussion presented here. Any comment?

8. Joe Born says:

“But the complex computer climate models show averages of only about 2.5% / C. There are no claims of reduced wind speeds or wave action or increased relative humidity to explain this.”

I would have thought it would be decreased, rather than increased, relative humidity that would result from lower partial-pressure increase.

9. TimTheToolMan says:

Mike writes “It seems reasonable to assume that precipitation would increase in line with evaporation: […]”

And yet they cant follow the logic through that the climate models underestimate the evaporation and hence surface energy lost through latent heat transfer to be deposited much higher in the atmosphere and subsequently radiated away…and hence overestimate the warming effect. No, instead they harp on about the 2C to 4C warming the models predict.

10. M Seward says:

Very interesting post. LHV is such a powerful energy transfer when you appreciate that 1 kg water evaporated can cool about 2000 kg of air by 1 degree. Taken together with the huge energy absorbtion into the chemical binds of biomass ( via CO2 + H2O + whatever= biomass) and the CO2 GH effect looks like a popgun facing a minigun. It seems to me almost emblematic of those “scientists” inside the AGW bubble world that they would not bother to get the science and the maths right on these things as that really would reveal an inconvenient truth.

11. Dr Burns says:

“6% / C” seems a great over simplification. The following is for fresh water:

E = 5([Tc+ 18]**2.5– r[Ta+ 18]**2.5)(V + 4) x 10**-6
where:
E = evaporation rate, kg/m2/h
r = relative humidity/100T
Ta= air temperature, °C
Tc= water surface temperature, °C
V = wind velocity, km/h.

12. Doug Huffman says:

This will be interesting to study in light of the “Decreasing Trend in Pan Evaporation.”

13. kazzog says:

If the author is correct, then this is a pretty big deal. Infact, this could be one of the most significant events in the debate against AGW.

14. Joe Born says:

I assume the capital gammas in Eq’n A3 should be Gs?

15. Doug says:

This might be a little tangential, but it is also connected to precipitation, and specifically the resolution being too coarse to pick up rainstorms.

While discussing the Lovejoy 99% paper it struck me that a lot of the measurement accuracy is obtained by removing inhomogeneities by statistical techniques. However, if you consider that things that lower the surface temperature (rainstorms) are smaller scale than the rest of of the climate (i.e. there are more places, covering a larger area, where it is raining rather than not raining at any given time). What’s more, this evaporation problem will also occur over land, because you will have increased evaporation where it has recently rained.

In this context, what you get by doing that is just a high pass filter, and the more “accurate” result, the higher the skew to the positive side will be. If that is correct (and do correct me if I am wrong) it is not just in the models that suffer from this problem, but the measurements too.

16. Joe Born says:

Isn’t your approach based on the assumption that the vapor pressure immediately above the surface reflects that general humidity level? Have you double-checked the evaporation rate against the rate of rainfall?

From my stream-of-consciousness question barrage above, you may justifiably infer that I haven’t yet completely comprehended the post. I nonetheless persist:

“From forcing at the TOA from CO2 at a typical emission level of about 10 km, one would think that the upward emission level temperature would increase more than the lower level. ”

I would have thought that CO2-caused forcing would be represented by a decrease in k matched by such an increase in G as to keep U + W equal to (a constant) S. That sounds like a constant emission-level temperature to me.

17. Rud Istvan says:

The CMIP3 models all underestimate precipitation by a factor of 2. There is a direct connection.
The CMIP3 and 5 models all produce a tropical upper troposphere hotspot when none is observed. Again, there is a direct connection.
If surface evaporation is misstated, yet relative humidity is maintained at all altitudes AR4 black box 8.1, then the water vapor feedback is overestimated by about half and mismodeled precipitation is direct evidence. The mismodeling is greatest in the tropics where more precipitation occurs (ITCZ), which is why models have a tropical hotspot while the world doesn’t. In the world, upper humidity is lowered by washout, and the latent heat left in the atmosphere is freer to radiate away.
None of this got corrected in CMIP5. Perhaps this post offers a specific fundamental reason why.

18. Joe Born says:

One last question before I turn to my taxes:

For someone who is good with the data sets, it should be relatively easy to apply your function of evaporation versus temperature to the gridded temperature data set,area-weight the results, and compare that with global average rainfall. Wouldn’t that be a good sanity check?

19. bobl says:

This doesn’t pass a smell test, if evaporation increases 6% then precipitation must increase a similar amount. Taking into account that average rainfall across the surface is a meter per annum and the specific heat of evaporation and change in potential energy between the surface and 3 km a forcing of at least 5.5W per meter squared would be required to break even on the energy budget to do this. Since the total forcing is only 3.7 Watts per square meter, and the imbalance only 0.6W per square meter, there is clearly insufficient energy in CO2 related reflected IR to sustain the 6% increase in the hydrological cycle, even at 5.5W per square meter, if there was a 6 % increase in evaporation then the cooling effect would completely cancel the warming, so it seems to me that a driving energy of considerably more than 5.5W per square meter would be required to sustain such an increased evaporation AND warm the atmosphere at the same time. (Of course then we should add in the other losses, such a heating gigatonnes of liquid water, melting a few gigatonnes of ice, sustaining increased photosysthesis, greater storm energies and all the other magical effects that are supposed to happen – apparently without expending any of that magical 0.6W of heating that’s supposed to be causing these effects

I need to understand where you think the energy is coming from to sustain this warming in the presence of such a huge increase in evaporation.

April 15, 2014 at 12:55 am

*I am always the smartest guy in the room.**”

He says, as he posts from a phone booth.

He, he…

21. “It seems to me almost emblematic of those “scientists” inside the AGW bubble world that they would not bother to get the science and the maths right on these things as that really would reveal an inconvenient truth.”
I have oten wondered if that is the sad and sorry case. They are certainly quite capable of correcting their errors to make sure those laughable models be much more accurate, but they resist, why?

Why do they continually demonstrate their complete ineptitude and bias by not fixing those models to reflect true current results, instead of their own biased, fantasy driven ever higher temperatures. It is just beyond comprehension. Does it refer to that old saying “better to let them think you’re stupid than to open your mouth and remove all doubt?’. I am perplexed by this entire scenario. Even when faced with the obvious facts like the examples above they will still continue on their ignorant and deliberate of scientific principles, theories and conduct.

22. I believe IEEE stands for Institute of Electrical and Electronics Engineers. Electrical engineers normally have a good grasp of mathematics but I am not so sure of their grasp of chemical engineering science. I have come across electrical engineers who have no idea of process control because they do not understand engineering science such as reaction kinetics, fluid dynamics or heat & mass transfer. Mention of physics instead of engineering science makes me suspicious. Instead of humidity you should be using partial pressures-just think of the lower pressures in a cyclone which helps evaporation at the warm ocean surface to feed in energy. For forced convection and evaporation I did not see any mention of the Nusselt number or Prandtl number. Engineers normally take great care with units and dimensions. Working with dimensionless numbers helps to get sensible answers. Every part of an equation has to be in the same units- you can not add or multiply apples and oranges.. By the way CO2 can not do any of forcing -check the units.
Fancy quoting Kiehl & Trenberth that paper would never be published in an engineering journal.

23. Pamela Gray says:

When the missing heat is found, might it be due to this very miscalculation?

24. Pamela Gray says:

From upstream in this thread, I too think this mathematical model as a number of checkpoints that can be possibly varified with observation. What additional checks have you made besides the one mentioned in the paper? Precip, humidty, temperature, pressure, etc are all sources of potential checks for this model besides observed evaporation rate.

25. Thank you for your efforts.

But – and you knew a “but” was coming didn’t you? 8<)

If we start with balance at the surface and again solve for G, we get the same result that also forces balance at the atmosphere.

Does that not "require" the usual assumption of a single flat-earth, flat-plate, one-sided, "average' earth at a single constant distance from the sun in a "perfect" equilibrium" with space?

Rather, how does your work change if you require the use of a "spotlight" solar heating on a rotating 24 hour sphere? Solar heating is NOT an uniform average of 324 watts over 24 hours, but is a constantly-changing value between 200 watts (at 07:00) to over 1150 watts (noon) to 0 (after dark, before sunrise.)

Today, for example, day-of-year 105 (15 April) the amount of solar energy on each square meter of the earth's surface at the equator each hour of the day on a clear day is NOT 324 watts, but the following:

01:00      0
03:00      0
05:00      0
07:00    184
09:00    747
11:00   1087
12:00   1131
13:00   1087
15:00    747
17:00    184
19:00      0
21:00      0
23:00      0


So, your “equilibrium model” must evaporate, radiate (long wave), convect, and conduct (from the upper 2 millimeters of water to the depths), not 342, but 1131 watts (at the equator, at noon.) But, over night, an adequate model must change to evaporate, long wave radiate, convect, and conduct 0.0 SW solar radiation, and cool the ocean using the available stored energy from the previous day.

But the earth at any latitude is not radiated evenly either, and the north-south distribution invalidates a simplified flat-plate radiated evenly at equilibrium mode as well. Same day-of-year as above, same one square meter flat surface at noon as above, same clear skies in direct sunlight as above, but at each latitude.

 +85      178
+80      278
+70.6     467     (Southern Edge of 2012 Arctic Sea Ice this doy)
+70      479
+67.5     527     (Arctic Circle)
+60      666
+50      830
+40      965
+30     1065
+23.5    1110    (Tropic)
+20     1127
+10     1150
000     1131    (Equator)
-10     1073
-20      977
-23.5     935     (Tropic)
-30      846
-40      684
-50      499
-60      299
-64.4     211   (Northern Edge of 2011-2013 Antarctic sea ice extents this doy)
-67.5     150   (Antarctic Circle)
-70      104
-80        0
-85        0


26. William Astley says:

Old England says:
April 15, 2014 at 1:24 am
Interesting, and the effect of convection on the calculations is ?
William:

The following is the calculated affect on global warming of a change in evaporation from the same author warming for a doubling of atmospheric CO (nominal) = 0.84C with IPCC assumed positive feedback from clouds, 0.73C with neutral feedback from clouds, and 0.64C with negative feedback from clouds.

http://climateclash.com/improved-simple-climate-sensitivity-model/

Table 1 – Surface Temperature Increases for 2xCO2 with feedbacks (Min/Nominal/Max)
1) IPCC(2007) with constant evaporation and Ts =3010_______ 2.00/3.20/4.5 C
2) IPCC(2007) with constant evaporation and Ts =2645_______ 1.60/2.29/2.89 C
3) Same as above with 2.5%/C evaporation change rate______ 1.25/1.33/1.58 C
4) Same as above with 6%/C evaporation change rate________ 0.69/0.84/0.97 C
5) Same as above with no (William: Neutral) cloud feedback __0.61/0.73/0.82 C
6) Same as above with negative cloud feedback____________0.55/0.64/0.71 C

27. Bob Shapiro says:

Either I’m confused, or several commenters are confused (or both).

The article assumes a constant relative humidity, so the evaporation would need to be greater and would cause more water to STAY in the atmosphere. This water cannot then cause surface reheating by additional rainfall because by definition it is staying up there. (This doesn’t mean the water cycle can’t go up or down separately, just not with this water. BTW, alarmists need to demonstrate water cycle changes using data and not models.)

So the net effect of 6% more evaporation per degree C, is a negative feedback which isn’t being caught by the GCMs.

If I’m wrong, please tell me. Thanks.

28. William Astley says:

bobl says:
April 15, 2014 at 6:04 am
This doesn’t pass a smell test, if evaporation increases 6% then precipitation must increase a similar amount. Taking into account that average rainfall across the surface is a meter per annum and the specific heat of evaporation and change in potential energy between the surface and 3 km a forcing of at least 5.5W per meter squared would be required to break even on the energy budget to do this. Since the total forcing is only 3.7 Watts per square meter, and the imbalance only 0.6W per square meter, there is clearly insufficient energy in CO2 related reflected IR to sustain the 6% increase in the hydrological cycle, even at 5.5W per square meter, if there was a 6 % increase in evaporation then the cooling effect would completely cancel the warming, so it seems to me that a driving energy of considerably more than 5.5W per square meter would be required to sustain such an increased evaporation AND warm the atmosphere at the same time.
William:
The temperature of the planet will warm less than 1C for a doubling of CO2. There will not be 6% increase in evaporation.

Your comment suggests using forcing in watts to force the evaporation rate of the oceans. That confuses the issue. The evaporation of ocean is controlled by temperature at the surface of the ocean (and the variables noted in the next sentence.). The amount of water evaporation is not a free variable that can be changed to tune the general circulation model.
Physics controls the evaporation rate of water based on the controlling variables temperature, relative humidity above the water, wind speed, and wave action. The evaporation rate is not a free variable that can be change by the IPCC in their general circulation models to give the answer they want.
William:
The following is the calculated affect on global warming of a change in evaporation from the same author warming for a doubling of atmospheric CO (nominal) = 0.84C with IPCC assumed positive feedback from clouds, 0.73C with neutral feedback from clouds, and 0.64C with negative feedback from clouds.

http://climateclash.com/improved-simple-climate-sensitivity-model/

Table 1 – Surface Temperature Increases for 2xCO2 with feedbacks (Min/Nominal/Max)
1) IPCC(2007) with constant evaporation and Ts =3010_______ 2.00/3.20/4.5 C
2) IPCC(2007) with constant evaporation and Ts =2645_______ 1.60/2.29/2.89 C
3) Same as above with 2.5%/C evaporation change rate______ 1.25/1.33/1.58 C
4) Same as above with 6%/C evaporation change rate________ 0.69/0.84/0.97 C
5) Same as above with no (William: Neutral) cloud feedback __0.61/0.73/0.82 C
6) Same as above with negative cloud feedback____________0.55/0.64/0.71 C

29. wsbriggs says:

Slow to follow:

Here’s a [pointer] to a calculator for the evaporation from a body of water. Inputs are rel humidity, abs humidity, air temp, water [surface] temp, and wind velocity.

Any commenters who haven’t worked the examples, nor done the math, are simply muddying the waters of human knowledge. Arguments to authority, ad hominum (IEEE is an engineer…), are bogus as always.

30. Crispin in Waterloo says:

The ultimate conclusion is that thunderstorms are the main mechanism for cooling of the oceans. I think the assumption that the oceans are 17 is wa-ay wrong. Evaporation is far higher where the oceans are warmer because that is where more insolation lands.

Minor point re the acceleration of the water cycle – there can be a great deal of condensation on the water at night without ‘precipitation’ and it goes unnoticed. In other words the argument that the 6% increase is ‘too much’ should be examined in the light of all routes for returning water vapour to the sea.

@Dr Burns
++++++
E = 5([Tc+ 18]^2.5– r[Ta+ 18]^2.5)(V + 4) x 10^-6
where: E = evaporation rate [kg/m^2/h]; r = relative humidity/100T [units?]; a= air temperature [°C]
Tc= water surface temperature [°C] ; V = wind velocity [km/h]

+++++

I was unable to turn that into a spreadsheet.

r = % or …?
What is Ta ? Air Temp in C?
What is 100T ?

Thanks

31. Mods – Correction to previous post – water surface temp

32. Greg Goodman says:

“The IPCC has a positive cloud feedback of 0.69 Wm-2 / C with a very large range. But it is not based on reduced clouds with warming, but as a residual of the amount of warming the models can not explain by the other feedbacks (Soden and Held (2006), p 3357, paragraph 2). So this is not a true estimate of cloud feedback. Eliminating it and replacing the lapse rate feedback with our evaporation feedback cuts the IPCC feedback multiplier from 2.48 down to 0.910.”

OMG, they really are just making it up. This is totally a fudge factor.

I think tropical sensitivity to a change in radiation is near zero once the climate has settled which takes 2-3 years after an impact like a major volcano. Extra-tropics are more sensitive but buffered to a fair extent by exchanges with the tropics due to major ocean gyres.

I think these values are a lot more credible.

Sorry don’t have time to plough through the maths but it looks well thoughtout.

33. Trenberth himself acknowledges that the climate models ignored evaporative cooling from Tropical Cyclones of 1.13 Wm^2 see the last Fig in my post at
http://climatesense-norpag.blogspot.com/2013/02/its-sun-stupid-minor-significance-of-co2.html
I said in this post from about a year ago
“The modelling community and the IPCC have both recognized that they have a problem. For example both Hansen and Trenberth have been looking for the missing heat and generating epicycle type theories to preserve their models. Hansen thinks it might have something to do with aerosols and Trenberth first wanted to hide it down the deep ocean black hole. Death Train Hansen is a lost cause as far as objective science is concerned but Trenberth has always been a more objective and judicious scientist and has recently made excellent progress in discovering a real negative feedback in the system. see
http://www.cpc.ncep.noaa.gov/products/outreach/proceedings/cdw31_proceedings/S6_05_Kevin_Trenberth_NCAR.ppt

Note PPT slides 38,39 and 40
He says this TC cooling of 1.13Wm^2is important relative to the CO2 radiative forcing of 1.5 Wm^2 and has not been included in the climate models . I’m sure this negative feed back was not included in the latest AR5 report sensitivity calculations..

34. Greg Goodman says:

One thing that is important in all this is that downwards IR ( radiation does not “well” in any direction ) is absorbed in the top 100 microns of the water surface.

It thus must heat this thin film and it is just where evaporation happens and it is this temperature which is relevant to the effect of the radiation.

Several people have pointed out that you can’t heat a ventilated body of water with IR. It simple increases evaporation. Unless I’ve missed by scanning the article too quickly this does not seem to be accounted for.

It would seem that the above account would apply to visible and UV which can penetrate deeper into the bulk of the water.

However, I think this is an excellent article, I shall come back and pour over it when I have more time.

35. William Astley says:

William:
A ‘smell’ test to confirm the conclusion that warming due to a doubling of atmospheric CO2 will be significantly less than 1C is Idso’s calculations. Idso uses 10 different natural phenomena where a known forcing change caused by different natural phenomena is used to calculate the planet’s sensitivity to a change in forcing. Idso’s best estimate for the warming for a doubling of atmospheric CO2 from that calculation is 0.4C.

http://www.mitosyfraudes.org/idso98.pdf

CO2-induced global warming: a skeptic’s view of potential climate change by Sherwood B. Idso

Over the course of the past 2 decades, I have analyzed a number of natural phenomena that reveal how Earth’s near-surface air temperature responds to surface radiative perturbations. These studies all suggest that a 300 to 600 ppm doubling of the atmosphere’s CO2 concentration could raise the planet’s mean surface air temperature by only about 0.4°C. Even this modicum of warming may never be realized, however, for it could be negated by a number of planetary cooling forces that are intensified by warmer temperatures and by the strengthening of biological processes that are enhanced by the same rise in atmospheric CO2 concentration that drives the warming.

This author reaches a similar conclusion that the planet will warm significantly less than 1C for a doubling of atmospheric CO2 due to enhanced evaporation.

http://typhoon.atmos.colostate.edu/Includes/Documents/Publications/gray2012.pdf
The Physical Flaws of the Global Warming Theory and Deep Ocean Circulation Changes as the Primary Climate Driver
….These two misrepresentations result in a large artificial warming that is not realistic. A realistic treatment of the hydrologic cycle would show that the influence of a doubling of CO2 should lead to a global surface warming of only about 0.3°C – not the 3°C warming as indicated by the climate simulations….

But this pure IR energy blocking by CO2 versus compensating temperature rise for radiation equilibrium is unrealistic for the long-period and slow CO2 rises that are occurring. Only half of the blockage of 3.7 Wm-2 at the surface should be expected to go into temperature rise. The other half (~1.85 Wm-2) of the blocked IR energy to space will be compensated by surface energy loss to support enhanced evaporation. This occurs in a similar way as the earth’s surface energy budget compensates for half its solar gain of 171 Wm-2 by surface to air upward water vapor flux due to evaporation.

Note in Figures 1 and 2 that the globe’s annual surface solar absorption of 171 Wm-2 is balanced by about half going to evaporation (85 Wm-2) with the other half (86 Wm-2) going to surface to atmosphere upward IR (59 Wm-2) flux and surface to air upward flux by sensible heat transfer (27 Wm-2). Assuming that the imposed extra CO2 doubling IR blockage of 3.7 Wm-2 is taken-up and balanced by the earth’s surface as the solar absorption is taken-up and balanced, we should expect a direct warming of only ~ 0.5°C for a doubling of the CO2. The 1°C expected warming that is commonly accepted assumes that all the absorbed IR goes to balancing outward radiation (through E = σT4) with no energy going to evaporation. This is not realistic. These two figures show how equally the surface solar energy absorption (171 Wm-2) is balanced by a near equal division between temperature rise (enhancing IR and sensible heat loss) and energy loss from surface evaporation. We should assume that the imposed downward IR energy gain for a doubling of CO2 at the surface will likely be similarly divided. Such a division will cause an enhancement of the strength of the hydrologic cycle by about 2 percent (or 1.85 Wm-2 of extra global average evaporation over the ~ 85 Wm-2 energy equivalent of current evaporation).

This analysis shows that the influence of doubling atmospheric CO2 by itself (without any assumed positive feedback) leads to only very small amounts of global warming.

36. wsbriggs says:
April 15, 2014 at 7:48 am

Here’s a [pointer] to a calculator for the evaporation from a body of water. Inputs are rel humidity, abs humidity, air temp, water [surface] temp, and wind velocity.

Other users are reminded that – unlike many equations – there are as many different models and computerized linear approximations for evaporation losses from open water sources from as many different labs, universities, docs, post-docs, pre-docs, and graduate thesis as could be funded or approved by as many different departments and universities that ever existed. Papers have been written on these losses by as many different people as can apply for grants and thesis topics.

I recommend the ONLY evaporation/heat loss/heat transfer equations and models that anybody uses are those who simultaneously list the experimental conditions: latitude, relative humidity, area, weather conditions (air temperature, wind measurements, cloudy/clarity, radiation levels, relative humidity and wet bulb temperatures, measurement dates, level records, water temperature AT A MINIMUM) .

Then, once the reader is shown the actual conditions that “validate” each different approximation (model) he or she can evaluate whether that particular model is going to be valid for any particular situation. In particular, I distrust greatly “generic” computer models that do not list what very few conditions exist that validate the model.

For example: I’ve checked several different models that claim they predict the heat equilibrium for various swimming pools under various conditions; indoor closed cover, outdoor, indoor open room, outdoor exposed to sunlight, etc. Nice models, but they differ between equal conditions by as much as 100%! (50 watts/meter^2 losses compared to over a 100 watts/meter^2) ! Further, a “swimming pool” model may be valid for average conditions in swimming pool conditions: 80-100 deg F air temperatures, relative humidity of 30 – 70%, sunshine skies at 34-45 degrees latitude in the summer, etc. Does that mean they are accurate for any square meter of Arctic ocean water at 2 deg C, winds = 10 m/sec, air temperature of -15 deg C at a relative humidity of 30% under cloudy skies at latitude 78 north?

You mentioned IEEE – an good organization usually valid. But, even the ASHRAE – the specific heating and Air Conditioning Engineering Society (ie, heat exchange and cooling specialists working in a field SPECIFICALLY using relative humidifies and air temperatures!) have been accused in various papers of mis-calculating evaporation heat losses in their long-used “standard model” by over 30%.

37. Ian L. McQueen says:

I looked for a mention of the Clausius-Clapeyron relationship (equation) and did not find any. Is this not an application?

Ian

38. Frank says:

Richard: I’ve been interested in analyzing radiative forcing from a surface energy balance perspective rather than the balance across the tropopause. The instantaneous increase in DLR (from RTE) associated with 2XCO2 is only 0.8W/m2 at the surface, while the change at the tropopause is 3.7 W/m2. The 0.8 W/m2 at the surface will be amplified by water vapor feedback; call this 0.8*f W/m2.)

The surface can get rid of this excess energy by two mechanisms: warming until the surface radiates an additional 0.8*f W/m2 or by increased evaporation. From a surface perspective, climate sensitivity is controlled by the ratio of these two routes to escape the surface. However, the rate of evaporation is mostly controlled by wind speed, not the surface temperature of the water. This is because the layer of air immediately above the surface of the ocean is saturated with water vapor and the slow step in is mixing that saturated air into the boundary layer. (We can experience this difference leaving a pool on a warm windy day vs a warm still day.) I’m not sure how GCM handle this problem, but their failure to predict the full increase in rainfall with GW is proof that they haven’t got moisture transport into and out of the boundary layer right.

39. jorgekafkazar says:

“No energy constraints of evaporations are seen.”

Something is wrong, then.

40. Berényi Péter says:

Electromagnetic forces are strong compared to gravity. To move a water molecule from liquid to gas phase 1 micron above the surface needs about the same amount of energy as moving it to an elevation of 15 miles against gravitational gradient. Evaporation matters.

41. William Astley says:

Another smell test that we have found a significant modeling ‘climategate’ fudge is other papers discussing the issue and a response from one or more of the climategate cabal.

This paper explains how the general circulate models suppress evaporation of the oceans.

Muted precipitation increase in global warming simulations: A surface evaporation perspective by Ingo Richter and Shang-Ping Xie

One of the important consequences of a rise in global atmospheric temperatures is the increase of the atmosphere’s capacity to hold water vapor in accordance with the Clausius-Clapeyron (CC) equation. Under the assumption of constant relative humidity, this implies an increase in specific humidity at the rate of ∼7% per Kelvin of atmospheric warming, a prediction roughly borne out by observations and model simulations.

If, in addition, the atmospheric circulation remained approximately unchanged, we would expect precipitation to increase at a similar rate as water vapor. This, however, is not what is predicted by a wide array of climate models, which put the rate of precipitation increase at just 2%/K [Held and Soden, 2006].

One way the models can achieve this muted precipitation response is through a slowdown of the tropical circulation so that the decrease in upward velocity partially offsets the increase in atmospheric moisture [Emori and Brown, 2005]. Such a slow down is confirmed for the simulated Walker Circulation [Vecchi and Soden, 2007] and, to a lesser extent, for the Hadley Circulation [Lu et al., 2007]. [3]

The muted precipitation increase and slowing of the tropical circulation constitute a consistent response to greenhouse gas (GHG) forcing among models but it is not obvious why the climate system should behave in this particular manner. In fact, recent observational studies by Wentz et al. [2007] and Allan and Soden [2007] suggest that the actual rate of precipitation increase might be significantly higher than what is simulated by climate models. Similarly, a recent analysis of surface heat flux using merged satellite and reanalysis data [Yu and Weller, 2007] indicates a rate of latent heat flux increase that is much higher than in the models.

42. Berényi Péter says:

Global average precipitation is 990 mm/annum, evaporation should be the same. Precipitation over land is 715 mm/year. Of this 210 mm (31,500 km³) is lost as river runoff to sea, the rest is evaporated. Therefore evaporative cooling is significant even over land, over oceans it is only about twice as much.

Also, river runoff indicates a 16 W/m² latent heat import by the global land area.

Moreover, about 90% of water droplets in clouds are evaporated in mid air (at the cloud base), before falling to the surface as precipitation. Water vapor rises again, then recondenses at a higher elevation releasing its latent heat content. Therefore water plays an even more significant role in moving heat to higher elevations than usually assumed. Also, this is how clouds stay afloat in spite of liquid or frozen water being heavier than air.

It is not easy to calculate rate of evaporation, because it does not only depend on temperature and relative humidity, but also on area of water-air interface. In calm weather it is the surface area of oceans, but as soon as wind is strong enough to generate spray, interface area is increased by many orders of magnitude.

Over land effective interface area is mostly set by vegetation. In forests total leaf area alone is much higher than the area covered by trees (it is the same in grasslands). On top of that internal surface of stomata (microscopic cavities on backside of leaves) is even higher and they are opening and closing on demand, therefore rate of evaporation is regulated. At higher atmospheric CO₂ concentration there is less need to open up those breathing holes, so evaporation per unit leaf area is decreasing. However, it is compensated by an increasing total leaf area, which tends to maintain higher primary production of biomass with the same water consumption as before.

43. george e. smith says:

Well I am not a believer; but I applaud Richard’s effort.

It’s the latent heat; his G that bothers me.

Now Ice remains ice even at zero deg..C unless, and until, you add 80 calories per gram of ice to cause the phase change from ice to water still at zero deg. C That’s what latent heat is. And water does not become ice until something colder sucks out that 80 calories per gram at zero deg. C to allow the phase change.

The same thing happens at the other end. Water remains liquid even at 100 deg. C until something hotter supplies it with about 590 calories per gram to cause the phase change to water vapor.

And conversely, water vapor remains vapor until something COLDER sucks out that 590 calories per gram to allow it to condense. NOTHING GETS WARMER !! in the process.

The water when it precipitates out as rain or whatever, does not bring any “latent heat” back down to the ground. That was already sucked out by the colder upper atmosphere to get the water.

At Temperatures below 100 deg. C the evaporation of water requires a somewhat larger latent heat absorption. Common sense tells me the amount is equal to the 590 value at 100 deg. C plus another calorie per gram, for each degree below 100 deg C you are at. Maybe it’s not that simple, but that would be my bet.

People have to stop thinking that latent heat is a source of Temperature rise.

When you put your hand in steam and get scalded, it IS NOT that the latent heat of condensation (590 cal per gram) raises the Temperature of your skin above 100 deg C, it is simply that you get a dose of 590 plus the difference between the 100 deg. C stam Temperature, and your 98.6 deg. F body Temperature.

The amount of “heat” energy dumped in your skin is much higher than hot water, but the Temperature is no higher than 100 deg. C

Please stop saying that latent heat warms the atmosphere; it doesn’t.

44. Matthew R Marler says:

Greg Goodman: Several people have pointed out that you can’t heat a ventilated body of water with IR. It simple increases evaporation. Unless I’ve missed by scanning the article too quickly this does not seem to be accounted for.

Do you have references for that? I may have asked before and missed the answer; if so, I apologize.

45. Matthew R Marler says:

Berényi Péter

Global average precipitation is 990 mm/annum, evaporation should be the same. Precipitation over land is 715 mm/year. Of this 210 mm (31,500 km³) is lost as river runoff to sea, the rest is evaporated. Therefore evaporative cooling is significant even over land, over oceans it is only about twice as much.

Do you have references for those numbers? I’d like something to down load to my file on this topic.

46. Matthew R Marler says:

Richard J. Petschauer,

That was a most illuminating post. Thank you.
I look forward to your response to RACookPE1978; addressing the distribution of temperatures, radiant fluxes, and evaporative changes, rather than calculations based spatio-temporal distributions. However, I think the main point that the GCMs are off is likely to withstand scrutiny.

Is your work available in pdf format? I can easily copy/paste, but I always fear (this may seem absurd) transcription errors.

47. Joe Born says:

I got back from taking the taxes the post office and was looking forward to enjoying the author’s sound defense of this post.

What a disappointment.

48. aaron says:

Told you so.

49. I will try to answer some of the questions in segmentsi

Evaporation.
My early work was on evaporation related to indoor swimming pools based on ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) empirical equations. I used them in conjunction of a device I designed, installed and patented to automatically adjust indoor room humidity without outside temperature and reduce condensation damage in the winter. These equations have the same property regarding how water temperature and air humidity affect changes in evaporation assuming things such as wind speed and wave action if they do not change (if they do that should be treated as and additional separate feedback). In only depends on the vapor pressure of water as a function of temperature and the temperature and relative humidity of the surface air. Water vapor pressure can be very accurately measured and I use Bolton’s equations [p = 6.112*exp((17.67*t) / (t+243.5)) mbars] which is a fit to real data and is more accurate at sea level that the general purpose Clausius – Clapeyron equation. Using Bolton’s I get going from 17C to 18C an increase ratio of 1.0652 and with the C-C equation 1.0640. But I am using only 6% as a conservative estimate. The question was raised if 17 C is too low. Using 30C drops it to 1.590, but that is too warm for an average. Near the equator, the wind speeds are less so it cuts its importance. Regarding wind speed, it is important, but at 100% relative humidity, net evaporation is zero for any speed. And as shown in indoor swimming pools with very little wind, the evaporation is certainly not zero. Incidentally, the water drop in inches per day is independent of the pool shape or area and can be used to measure evaporation after a few days. With no wind the water-air interface is still refreshed. Water vapor has a molecular weight of 18 compared to air at about 29, so the lighter, moist air will rise and be replaced with less humid air. And as the evaporation cools the water at the interface, its density increases so it will drop and force the warmer water below to rise. Wind speed will accelerate this.
The equation for indoor swimming pools uses an empirical “activity factor” multiplier which can greatly effect the final value.

Regarding Dr Burns comments “about 6% / C is too simple”. I “stated with constant with and constant relative humidity”. So what does he get with his empirical equation? If I understood it correctly, I got values ranging from 7.3% / C at 17 to 18C and at 5.29 %/ C from 30C to 31C which seem to be changing too fast with temperature.

50. bobl says:

@William Astley

No, I think my comment holds. Sure, if the temperature increases by 1 degree and the evaporation increases by 6%. What does that do to the energy budget given that you must evaporate 30,600,000,000,000 tonnes of water and raise it to 3km high What does that cost in energy? Given the additional energy for a doubling of CO2 is IIRC 3.7W per square meter, there is insufficient energy to sustain even a 1 degree rise. The situation is non-physical, as there is insufficient additional energy to sustain the temperature rise given the evaporation rate. To evaporate that much water you need more energy than the change in energy that was supposed to be driving it – You are energy saturated – ergo, doubling CO2 cannot raise temperature 1 degree.

Add to that the parts of that extra retained energy that goes into the atmospheric window, melting ice, heating oceans, plant growth , wind, waves and numerous other unclaimed losses, the liklihood of a non zero sensitivity diminishes quickly, and may even be negative, for example, in plant growth, the CO2 acts both as a reactant and a catalyst – the small increase in CO2 partial pressure leads to larger increases in the consumption of shortwave energy, and increases in transpiration extracting more energy than the CO2 puts in This is likely to have a nett near surface cooling effect

51. Brian H says:

Greg Goodman says:
April 15, 2014 at 8:12 am

However, I think this is an excellent article, I shall come back and pour over it when I have more time.

What will you be pouring over it? Is it sticky? Nosy minds want to know.
);p

“It’s just basic (fudged) physics!”

JohnWho says:
April 15, 2014 at 6:06 am
“He says, as he posts from a phone booth.”
——————————————————
Well I did say “dependant on room size” ;-)

The judges would also have accepted “broom closet”.

But broom closet or ball room makes little difference when up against lukewarmers. They are playing at a disadvantage. Desperately running around looking for a “sciencey” sounding solution that allows “warming but far less than we thought”. Lukewarmers cannot even contemplate the idea that they are as wrong as the believers and that radiative gases don’t warm at all.

The problem is indeed evaporation. The oceans are primarily cooled by evaporation. Without this they would become a giant evaporation constrained solar storage pond with temperatures topping 80C. An atmosphere without radiative gases cannot provide this cooling as it has no effective way of cooling itself.

Climastrologists have calculated the temperature of the oceans to be -18C in the absence of DWLWIR and atmospheric cooling and claimed that our atmosphere must be warming our oceans. Empirical experiment shows that figure to be out by 98C. The atmosphere is therefore cooling our oceans. And the only effective cooling mechanism for the atmosphere is radiative gases.

AGW is a physical impossibility, but that’s not the answer lukewarmers want.

53. Janice Moore says:

Given the following:

— “… the {water evaporation} rate varies from 6.2% to 6.9% / C. … the complex computer climate models show averages of only about 2.5% / C.” (Petschauer above)

— “The CMIP3 models all underestimate precipitation by a factor of 2.” (Rud Istvan 5:50am)

— “… today’s climate modelers propose that the “flea” wags “the dog.” The flea, of course, is carbon dioxide, and the dog, is the water cycle. … In effect, the theory assumes that the carbon cycle is controlling the more powerful water cycle.”
{Steve Goreham, here: http://wattsupwiththat.com/2013/10/07/climate-change-is-dominated-by-the-water-cycle-not-carbon-dioxide/}

— “Water vapor constitutes Earth’s most significant greenhouse gas, accounting for about 95% of Earth’s greenhouse effect (5).”
{Fred Singer, here: http://www.geocraft.com/WVFossils/greenhouse_data.html

{emphases mine}

Conclusion: The IPCC is doing its level best to make CO2
(and — LOL — even more preposterously, the ~4% which is human CO2 (when natural sources and sinks net CO2 does not overwhelm it so that it is 0%, that is))
and NOT water a significant driver of the weather in the climate zones of the earth. IOW — the IPCC is ly-ing or abysmally incompetent.

Which is it, IPCC “scientists?” Ev1l or stupid?

**************************************
{Note: THE FOLLOWING IS A BONA FIDE QUESTION about the above article — please, if you have the time to explain to a non-tech like I, I would really like to read your explanation. If it is a poorly worded question, please re-word and answer the more useful one. Thanks!}

Question:

Given the above quotes and also this fact: there is no evidence that CO2 causes temperature increases in an open system like the earth,

can Petschauer accurately and with a meaningful level of confidence assert this: “… latent energy for evaporation comes from the temperature of the water itself. … reduced net energy from increased CO2 still warms the surface, … .”
{bolding is to emphasize what I am asking about, here, affect on earth’s climate zones of CO2}

In a highly controlled laboratory experiment, okay. But, on WHAT PROOF, i.e., what MECHANISM, does he base this grand assertion about CO2 and the oceans of the earth?

THANKS FOR ANSWERING (until I get back here to say that)!

Janice

54. Janice Moore says:

A little allegory…

The IPCC and Water

Bwah, ha, ha, ha, haaaaaaaaa!

They are SO dead, lol. Now, it’s just the walking dead we are dealing with. Zombies can still fool people, though, so, sigh, HANG IN THERE YOU WONDERFUL WUWT SCIENTISTS FOR TRUTH!

Ev1l will always be with us; however, it need not be in control.

And, in the long run, it is not:

TRUTH WINS. EVERY TIME.

55. William Astley says:

The following satellite observational data and analysis from Roy Spencer’s blog site supports the assertion that the increase in evaporation for a 1C rise in ocean surface temperature is at least 6% rather than the IPCC’s assumed 2%

http://www.drroyspencer.com/2014/04/ssmi-global-ocean-product-update-increasing-clouds-with-a-chance-of-cooling/

“SSM/I Global Ocean Product Update: Increasing clouds with a chance of cooling
The water vapor variations lag the SST variations by an average of one month. A regression relationship reveals an average 10.2% increase in vapor per deg. C increase in SST. This is larger than the theoretically-expected value of 6.5% to 7% increase, a discrepancy which can be interpreted in different ways (more evaporative cooling of the ocean stabilizing the climate, or more water vapor feedback destabilizing the climate — take your pick).

The results find there is a slight increase in wind speed when the water is warmer rather than a decrease in wind speed, assumed by the IPCC which explains why the evaporation is greater than the theoretical 6%.”

William: It appears the IPCC is ignoring data that obviously indicates that their General Circulation Models (GCMs) are incorrect, at the actual warming due to a doubling of atmospheric CO2 will be less than 1C rather than 3C.

56. Joe Born says:

William Astley:

Thanks for the link to Dr. Spencer’s timely post.

I’m trying to determine whether the relationship was properly calculated between vapor content, which is what Dr. Spencer was referring to, and evaporation rate, which is what Mr. Petschauer’s E value refers to. It seems that vapor content would be the integral of the difference between (appropriately converted values of) evaporation and precipitation rates. I haven’t tried to figure that out.

Are you implying (or otherwise have an opinion about) whether the author or anyone has?

57. Terry says:

From Trenberth

“The results suggest an evaporative, total enthalpy, precipitation ocean cooling of:
0.16, 0.185, 0.58 PW over a year. Over the tropical ocean 20°N to 20°S the LH is equivalent to 1.5 W m-2 , or 1.1 °C/year over a 10 m layer. Globally this is 0.36 and 1.13 W m-2 vs CO2 radiative forcing 1.5 W m-2.
It matters! And it is not included in climate models.”

The question is how much of this not “accounted for” cooling is actually lost from the atmosphere via upper air radiation to space. Or is it all considered to be retained in the troposphere. If the latter, then I would assume that the overall effect (to a 1st approximation) would be small. On the other hand it may make a big difference to the model performance.

58. Steven Mosher says:

Radiative gases dont warm.
They lower the rate of energy loss to space.
The silver lining on a thermos does not warm the coffee
By reflecting radiation. It slows the energy loss.
Radiative gases are nothing much more than leaky reflective surfaces. They retard the return of energy to space. When we add ghgs we raise the erl. The higher erl
Means the earth radiates from a higher colder altitude.
That means a slower loss of energy to space.
Over 100 years ago we predicted an increase in co2 would result in a warmer planet. So far that prediction is correct.

59. David Riser says:

Thanks Richard, nice information based on real science with verification. For the doubters out there check out Wentz et al, as in “Data over oceans by Wentz et, al (2007) report values of about 6% / C.” Typical that inconvenient data doesn’t ever make it into the CAGW meme.
v/r,
David Riser

60. Matthew R Marler says:

bobl: Since the total forcing is only 3.7 Watts per square meter, and the imbalance only 0.6W per square meter, there is clearly insufficient energy in CO2 related reflected IR to sustain the 6% increase in the hydrological cycle, even at 5.5W per square meter, if there was a 6 % increase in evaporation then the cooling effect would completely cancel the warming, so it seems to me that a driving energy of considerably more than 5.5W per square meter would be required to sustain such an increased evaporation AND warm the atmosphere at the same time.

Not disputing you, but the author, Richard J. Petschauer, did not actually claim that doubling the CO2 concentration would increase the global mean temp by 1 C and raise the rate of evaporation by 6%. What he did was mimic some of the equilibrium type assumptions commonly used (mean temp as equilibrium, uniform surface and TOA, maintaining the same relative humidity, etc) and show how much difference is made in the standard computations by changing the relationship of vaporization change to temp change from that used by IPCC to a more realistic value.

I don’t believe that any of the equilibrium models are accurate enough to use for planning, and the GCMs are to date clearly too inaccurate to support planning. But if you take equilibrium calculation seriously, then this post shows that the inaccurate function for vaporization used in the GCMs is probably an important contributor to their inaccuracy. That’s how I read it.

I have posed the question: If doubling CO2 increases downwelling LWIR by 3.7 W/m^2, how much of the energy transfer goes to warming the water and near-surface air, and how much goes to vaporizing the water (in the non-dry parts of the Earth surface)? His calculations and your calculations suggest that most has to go to vaporizing the water, and little to temperature increase.

61. Janice Moore says:

Mr.! Steven! Mo-sher!

HOW CAN YOU SAY THAT WITH A STRAIGHT FACE?

I can’t read it without smiling …….. (you can’t be serious)

Hey….. I think……. I saw you, yes….. oh, now…. don’t smile, Mr. Mo-sher, dooon’t smiiiille….. .

#(:))

Seriously….
“… an increase in co2 would result in a warmer planet. So far that prediction is correct… .” (you this evening)

Down –> goes –> the –> gauntlet
(or, in my case, the cerise kid glove)….

Prove it!

So far, all the AGWers have is: post hoc, ergo propter hoc.

Still hoping you will come back from the dark side,

Janice

62. Janice Moore says:

And, for NOW, AGWers don’t even have post hoc ergo propter hoc to wave around, lol.

CO2 UP. WARMING STOPPED.

63. David L. Hagen says:

Richard J. Petschauer
Thanks for the modeling. For some data to test against, may I refer to you WJR Alexander, Development of a multi-year climate prediction model, Water SA= 2007 http://www.wrc.org.za Dept. Civil, Biosystems Engineering, Univ. Pretoria. Pretoria 0002, So. Africa. Alexander compiled all hydrological records in Southern Africa, available on CD by request. He found that rainfall and hydrological flows BUT NOT surface evaporation were driven by the ~ 21 year Hale solar cycle.

Steven Mosher says:
April 15, 2014 at 4:52 pm
————————————
“Radiative gases don’t warm.”

I’m well aware the the claim is “slow the cooling rate”. Semantics won’t save you.

“They lower the rate of energy loss to space.”

Without radiative gases our atmosphere would have no radiative cooling ability at all. So for the atmosphere they increase the energy loss to space. An atmosphere without radiative gases would have its temperature driven by surface Tmax, but would have no effective cooling mechanism. Empirical experiment proves conduction back to the surface ineffective.

“When we add ghgs we raise the erl. The higher erl means the earth radiates from a higher colder altitude.”

There is no such thing as ERL or EEH. These are a mathematical fiction used only by climastrologists. The simplest empirical experiment disproves the very concept of an average ERL. Go outside on different days in different weather conditions and scan the sky with an IR thermometer. The atmosphere is radiating in ever changing patterns from ever changing altitudes.

“Over 100 years ago we predicted an increase in co2 would result in a warmer planet. So far that prediction is correct”

Correlation is not causation. The warming since the little ice age started well before any significant human CO2 emissions.

The bottom line is this –

The sun heats our oceans.
The atmosphere cools our oceans.
Radiative gases cool our atmosphere.
AGW is a physical impossibility.

Steven, the climastrologists have made a fist-biting error in the very foundation of their claims. They used “blackbody” calculations to claim the oceans in the absence of DWLWIR or atmospheric cooling would have a Tmean of -18C. This is totally and utterly wrong. Our deep transparent oceans are not a “blackbody”, they are a “selective coating” over 71% of the lithosphere. Empirical experiment proves that the oceans in the absence of DWLWIR and atmospheric cooling would be at 80C or beyond. That’s a 98C error for 71% of the Earth’s surface! You can’t laugh that one off.

You may object to my use of crude language, but there is no other way to put it. 97% of climate “scientists” are assclowns!

65. Regarding some of Joe Born’s questions
Joe Born says:
April 15, 2014 at 1:36 am
“But the complex computer climate models show averages of only about 2.5% / C. There are no claims of reduced wind speeds or wave action or increased relative humidity to explain this.”
I would have thought it would be decreased, rather than increased, relative humidity that would result from lower partial-pressure increase.

What I mean is that increased humidity beyond that to maintain relative humidity would explain a reduced evaporation rate, but none of this has been claimed by the models or data. In fact a paper I just discovered (cited by the IPCC, Dai, et al 2006) data (not models) indicates RH drops a little with temperature which means evaporation will increase more than I estimated.

Joe Born says:
April 15, 2014 at 1:27 am
Is conductive loss so low that Equation (1) can ignore it?
“And the latent heat deposited in the atmosphere warms it and increases the downwelling radiation.” Is that correct? I had thought increased heat would increase radiation only after it became sensible.

Yes, only when latent heat turns into sensible heat can it warm anything. But that happens when the rising air cools and forms clouds. In the summer one can watch the large high clouds growing at the top from the heat rising from below as more water is condensed. This causes more heat to be radiated to space which the cools the planet. And those high cloud tops are above most of the water vapor where CO2 covers only about 20% of the radiation band so it can’t stop much.

Joe also pointed out that the equations in the apendix, A3 to A6, did not convert correctly from my Word document the Greek letters for partial derivatives. I will correct these with a non “Greek” version and post them here.

66. Dr. Strangelove says:

Richard Petschauer

You get 6%/C if relative humidity remains constant. But it will decrease because evaporation cools the water. So water temperature drops as well as its vapor pressure. But air remains warm and its absolute humidity at saturation point increases with temperature. You get initial increase in evaporation then decrease. You average the two. 6%/C if only increase and no decrease.

67. These are versions ot the Appendix equations (A3) to (A6) without bthe Greek partial derivative symbols.

At the lower part of the atmosphere,
A 1 W/m2 increase in E, A or H or a 1 W/m2 decrease in D will cause
a decrease in G (in W/m2) of – k / (1 – a + ak) (A3)

At the top of the atmosphere for longwave radiation only, a 1 W/m2 decrease in outgoing radiation will increase G (in W/m2) by (k – 1) / (1 – a + ak) (A4)

For change in net solar, S, shortwave incoming radiation, the forcing is substantially larger than for longwave radiation, contrary to present models that treat them as equal:

From changes in the solar strength, a 1 W/m2 increase in net incoming solar radiation
will increase G (in W/m2) by (1 – kA / S) / (1 – a + ak ) (A5)

From changes in albedo, a 1 W/m2 decrease will increase G (in W/m2) will increase G (in W/m2) by1 / (1 – a + ak) (A6)

68. David Riser says:

I think the point of the 6-7% is actually the measured evap increase/C. The point being the models being set at 2%/C guarantees they don’t follow reality. We know the models don’t follow reality and this is merely a reason why. Trying to say that measured reality is impossible is pretty much what the CAGW folks do daily. Obviously in local conditions water temp does in fact increase over time and then decrease, this drives the water cycle. The static annual average of global temps used to measure GW mean nothing when it comes to actual local conditions. The truly astonishing thing is how little the very meaningless annual average varies.
v/r,
David Riser

69. From changes in albedo, a 1 W/m^2 decrease will increase G (in W/m2) will increase G (in W/m^2) by1 / (1 – a + ak)(A6)

Janice Moore says:
April 15, 2014 at 3:30 pm
———————————-
Janice,
yes, it is the water that’s going to get them in the end ;-)

It seems they forgot that there is a big puddle of it 4-5 km deep covering 71% of the planet’s surface.

When you look at what the maths would actually mean, the Church of Radiative Climatology is actually claiming that our atmosphere is acting to warm the oceans. I think those big fluffy white things in the sky rather indicate that our atmosphere is cooling the oceans. I would have thought some of the climastrologists might have noticed, but apparently not…

71. Curious George says:

There is an excellent reason why at least one IPCC model (CAM5) has a problem with evaporation: it treats a latent heat of water evaporation as a constant, independent of temperature (in reality, it is 3% lower at 30 C than at 0 C) – http://judithcurry.com/2013/06/28/open-thread-weekend-23/#comment-338257. Modelers take it philosophically: why should a latent heat, of all things, be treated correctly?

For comparison, with an average Earth surface temperature about 290 K, a 3% error is 8.7 degrees K (or C), or 15.6 degrees F.

72. Janice Moore says:

Thank you, so much, for honoring me with a response. A person can easily start to feel like they just don’t know the secret WUWT password for recognition or something. I have wondered from time to time, “Why?” Even compliments or “Hi! How are you?’s” roll away, and fall through a crack in the floor, never to be seen again. I am often attacked, but seldom answered thoughtfully. And rarely spoken to kindly (waaa, I miss Mario — many of us do, no doubt; he’s just busy with work and car racing). Mostly, I’m ignored (I mean IGNORED — people post BELOW something I’ve said and harshly criticize me for what I just corrected or NEVER EVEN SAID — they write with complete disregard for what I wrote about AT LENGTH an hour or more above them; I think, “You obviously never even read my post… .”).

Meh, that’s just pretty typical for ALL of us commenters, I think. Nothing personal. What IS a personality issue is what it is about me that makes me even think much about this issue — even more, what it is that made me write about it, here, LOL.

Well, even if no one reads all that, it helped me to sing the “blogger blues” for a few bars. Better now!

Keep up all your fine argument on behalf of truth using evidence.

Gratefully,

Janice

73. There still seems to be some confusion about where the energy comes from to support the evaporation. I am basicly treating the evaporation as negative feeback, regardless of what changes the surface temperature and even if it is an increase or decrease in temperature. And the process feedbacks on itself. So for an initial change of 1C that will cause a 6% increase in evaporation cooling, this will reduce the evaporation along with the initial temperature rise.

From page 3:
“To determine the feedback factor for E, add to it the increase caused by a 1 C surface temperature change and convert the change in G to a temperature change. For a 6% increase of 78, E becomes 82.68, the new value of G is 386.0014 Wm-2, down from 390, and provides a temperature change of –0.741 C which equals the feedback factor, the temperature change before additional feedback. With no other feedbacks, the feedback multiplier is M = 1 / (1 – F); here we get M = 0.5744. The temperature change of –0.741 would produce another change of -0.741 x –0.741 or +0.549, followed by (–0.741)^3 or –0.406 then (–0.741)^4 or +0.301, etc which sum converges to a final temperature drop –0.4256 C which also equals M x F or -0.741 x 0.5744″.

Which validates the feedback equations that are based on how infinite series converge.

So the initial temperature change of +1C ends up at 1C – 0.4256 or 0.5744C and the evaporation would now be 6% x 0.5744 or about 3.44% higher (actualy 1.06 ^ 0.5744 or 3.40% higher).

The latent heat contained in the water is based on its temperature driven by the vapor pressure which is just a measure of the energy of the individual water molecues that allows them to escape the bonds of surface tension. You can’t have warming without it also increasing. There is a distribution of this energy so the more energtic ones can escape, reducing the average energy remaining which causes the cooling. At the same time water vapor molecues near the water surface are attracted to it and become liquid and this rate depends on the density of the water vapor molecules near the surface. The climate modelers can write their programs, but the water molecules don’t have to buy it. If a college physics major told his professor that the water was warming, but there was not energy to energy to support the estimated evaporation increase, he might be told he should consider changing his major. Maybe that’s where these climate model programers came from. The climate modelers justify their low estimates of evaporation increases based on their flawed energy balanced models. That what I show in the section with the Table. All the energy is balanced at all three levels up to a 10% / C evaporation increase. The warming started from a large 10 watt per square meter at the top of the atmosphere drop in outgoing radiation that present models say would increase surface temperature about 3C before any other feedbacks, I intenionally selected a large value with up to 10% evaporation changes to counter the “lack of energy” or a nonlinearity argument.

74. Janice Moore says:

Well! I’ll just take care of myself! And write this post from me to me, heh, heh.

Dear Janice,

How are you? …

Take care, dear,

Janice

lolololololololo

“Gonna Sit Right Down and Write Myself a Letter” — Ella Fitzgerald

75. TimTheToolMan says:

Mosher writes “Radiative gases are nothing much more than leaky reflective surfaces. They retard the return of energy to space.”

Ouch. Worst analogy ever.

Radiative gasses intercept the IR and capture it by vibrating more (the modes of capture are well understood) and then collide with a non-GHG (eg O2 or N2) and transfer that energy towards that molecule and hence warm the atmosphere.

Mosher likened it to “The silver lining on a thermos does not warm the coffee”

No, but the silver lining reflects all of the radiation back towards the coffee to minimise energy loss. Yes, to keep it warm. GHGs by comparison dont reflect anything back towards the ground. They capture IR and warm the atmosphere. They capture energy from the atmosphere and radiate both up and down for no net effect.

AGW “warming theory” comes from the TOA (as you later mentioned)

76. Janice Moore says:

@ Curious George (8:15pm) “a 3% error…” — Thank you for that jaw-dropping, helpful, statistic. Good for perspective!

********************************

Dear Mr. Petschauer,

Thank you for a fine article (even if I still have a Q about the CO2 remark in it). It is well-written and full of highly relevant information. Your careful, informed, analysis shows. That article took a lot of your time, no doubt. We are blessed that you shared it with us.

And GOOD FOR YOU to come back and answer questions or to clarify.

Gratefully,

Janice

77. Terry says:

Richard Petschauer

In your analysis you hold H as a constant. How realistic is that. Also your calcs indicate that for an increase in E there is no increase in U. Surely U must increase with an increase in E and H that both result from the increase in evaporation, and it is U that is actually important since it is the only pathway for the evaporative losses to escape the system.

78. bobl says:

Richard Petschauer,

Let me paraphrase, in order to avoid energy limitation arguments, you have used an assumption of available driving energy of 10W / square meter, not caring where it comes from.

The point I’m trying to make though is that in reality we energy constrained. We are told that a doubling of CO2 produces a driving energy of 3.7W per meter squared not 10W. What I was wanting you to do was to constrain your solution to 3.7 watts and calculate the maximum temperature change, and evaporation when that constraint is applied, or alternately calculate the energy required for an increase of 1C given that evaporation increases 6 % either way this makes for a quick comparison with IPCC models. I am not suggesting that the energy constraint would reduce the evaporation.

Eg the IPCC says that a doubling will cause 3.3 degrees of warming and by your calcs an attendant 20% increase in evaporation. Given that the energy is constrained to 3.7 Watts per square meter what is the revised temperature rise and evaporation rate. I’d assume that if we calculated the maximum extra evaporation that could be sustained by the excess energy, one could use the temperature/evaporation relation to tell us the temperature rise, all other losses ignored. By my estimate rather than 3.3 degrees and 20% we would get about 0.5 C temperature rise, and 3% evaporation for a doubling. That’s a big difference, a headline.

79. Joe Born says:

Mods:

I was about to suggest to Mr. Petschauer that he use LaTeX to get over his typographical problems above. If you speak LaTeX, all you do is put the math between dollar signs, as you do in LaTex, with the exception that after the first dollar sign you insert “latex” and a space.

The problem is that in the past it’s been best to try it first on the test page (saving your work before you submit), whereas today that page kept telling me that it could not accept my submissions (even without the LaTeX). So I’ll submit LaTeX here without testing it first:

$\frac{\partial G}{\partial U} = \frac{k - 1}{1 - a + ak}$

[Your values, your expression with latex worked in the above, but for “Everybody else” – those of us less skilled than you for example – the site policy is to “test” such functions and processes FIRST on the site’s Test page. Mod]

80. I will try to cover a number of comments and questions here

Regarding evaporation and precipitation:
It is usually agreed that globally over about a months average, precipitation will approximately equal evaporation since the atmosphere can’t hold that much water. But the sources of the evaporation and the destinations of the precipitation can be separated by very great distances. Evaporation is easier to calculate (if local temperatures, humidities and wind speeds are known), but precipitation is easier to measure, except some data over oceans may be lacking. What causes which? I would think evaporation is the main driver; however precipitation causes downdrafts of drier air that can enhance evaporation locally. Cloud formation is difficult to simulate, as is the onset of precipitation, except in the very short term such as in weather forecasting.

From Mike Jonas:
Confirmation by Dr Susan Wijffels on ABC (Australian Broadcasting Corporation) “Catalyst” program ..
http://www.abc.net.au/catalyst/stories/3796205.htm
“We’re already starting to detect and see big changes in the extreme events. And we’ve only really warmed the Earth by 0.8 of a degree. If we were to warm the Earth by 3 or 4 degrees, the changes in the hydrological cycle could be near 30 percent. I mean, that’s just a huge change, and it’s very hard for us to imagine.“
It seems extraordinary unreasonable to assume that precipitation could increase like that without there being a similar increase in evaporation.

My Response:
We won’t get increases as high as 3 to 4 degrees. Now they are admitting evaporation & precip rises 7.5 to 10%, but the models only use 2.5% to justify the warming. The increased temperature rise of 3 to 4 degrees can’t happen, because the increased evaporation will cut in almost in half and the lack of positive cloud feedback another large reduction.

Old England says:
April 15, 2014 at 1:24 am
Interesting, and the effect of convection on the calculations is?

My Response: Convection is the H in the equations. Here we use the estimate at 24 W/m squared. If it changes with surface temperature, it would be treated as an additional feedback factor the same way as evaporation. One would need to its change per C of surface temperature change. Since the atmosphere temperature tracks the surface, I would not think this is significant.

Joe Born says:
April 15, 2014 at 1:27 am
Is conductive loss so low that Equation (1) can ignore it?

My Response: Yes. Air that does not move has very little actual conduction; it is a fairly good insulator. Air moves heat by parcels of air moving either through convection (rising air thermals) or cooling air dropping. This net is the term H in the equation. Winds also move much heat from one area to another, but that does not enter into the global heat balance, but it helps distribute the heat and help make a global heat model work .

Frederick Colbourne says:
April 15, 2014 at 1:27 am
I understand this blog to support negative feedback from phase change in H2O at the surface and radiation of the energy from the top of the atmosphere.
The author observes that models that support global warming incorrectly posit an energy constraint on evaporation.
I conclude that this is what forces them to introduce positive feedback to make their model work.
I think my conclusion follows from the data and discussion presented here. Any comment?

My Response: I think they had the water vapor positive feedback there already. But I think you have a point in the case of the cloud feedback, which as I pointed out was simply manufactured so the simple energy balance models will give the same temperature rise from 2x CO2 as the models do (for the nominal value of about 3C; the maximum value of 4.5C is just because there is so much variation among the models). So just eliminating the cloud feedback (that’s probably a little negative with more water vapor) and correcting the evaporation rate feedback, the feedback multiplier drops from 2.48 to 0.91. And elimination of the uncertainty of the climate models could cut the maximum by about 30%.

My present project is to check on the large positive water vapor feedback claimed using both the IPCC estimate of its increase and that based on a large amount of data how it has varied across the globe.

bobl says: (See last Para)
April 15, 2014 at 6:04 am
This doesn’t pass a smell test, if evaporation increases 6% then precipitation must increase a similar amount. Taking into account that average rainfall across the surface is a meter per annum and the specific heat of evaporation and change in potential energy between the surface and 3 km a forcing of at least 5.5W per meter squared would be required to break even on the energy budget to do this. Since the total forcing is only 3.7 Watts per square meter, and the imbalance only 0.6W per square meter, there is clearly insufficient energy in CO2 related reflected IR to sustain the 6% increase in the hydrological cycle, even at 5.5W per square meter, if there was a 6 % increase in evaporation then the cooling effect would completely cancel the warming, so it seems to me that a driving energy of considerably more than 5.5W per square meter would be required to sustain such an increased evaporation AND warm the atmosphere at the same time. (Of course then we should add in the other losses, such a heating gigatonnes of liquid water, melting a few gigatonnes of ice, sustaining increased photosysthesis, greater storm energies and all the other magical effects that are supposed to happen – apparently without expending any of that magical 0.6W of heating that’s supposed to be causing these effects

I need to understand where you think the energy is coming from to sustain this warming in the presence of such a huge increase in evaporation.

My Response: First, I use 6% of 78 or about 4.68 W per meter squared, not 5.5. Secondly, you perhaps missed what I said twice in my essay, that the 6% applies to the temperature rise after the negative feedback and its temperature reduction process is complete. Assuming there are no other feedbacks (that would change the 3.7 value), my equation (3) shows 3.7 gives a surface temperature rise of 0.98 C before feedback. To get this, change k from 195 / (195 + 324) to (195-3.7) / (195-3.7 +324) from the change in G calculate a change in temperature (about 0.184 times the change). IPCC gets 3.7 / 3.2 or 1.16C. In my paper I gave a negative feedback factor for a 6% change in E of -0.741, which gives a feedback multiplier of 1 / (1 – F) or 1/ 1.741 or 0.5744. So the final temperature rise is drops to 0.98 x 0.5744 or 0.56C and the evaporation is 6% x 0.5744 times 78 (the original E) or about 2.68 W per meter squared larger. For a 0.56 temperature rise from the surface I get an increase in radiation of 3.04 W per meter squared for a total increase of 3.04 + 2.68 or 5.72 W per meter squared. But how can 3.7 W per meter squared at the top of the atmosphere cause a 5.72 increase at the surface?
Well in this case D increased by the same amount and supplied the energy. It’s the greenhouse multiplier. The same thing that causes 390 – 40 through the atmospheric window per meter squared leaving the surface when the net incoming solar heat is only about 235 W per meter squared. Note 350 / 235 = 1.50 and 5.72 / 3.7 = 1.55. The difference is a small additional increase in the amount through atmospheric window.

[block quotes added to increase clarity. Mod]

81. cementafriend says:
April 15, 2014 at 6:31 am
“I believe IEEE stands for Institute of Electrical and Electronics Engineers. Electrical engineers normally have a good grasp of mathematics but I am not so sure of their grasp of chemical engineering science. I have come across electrical engineers who have no idea of process control because they do not understand engineering science such as reaction kinetics, fluid dynamics or heat & mass transfer. Mention of physics instead of engineering science makes me suspicious. Instead of humidity you should be using partial pressures-just think of the lower . . . .

Kiehl & Trenberth that paper would never be published in an engineering journal.”

My Response
First, I am using partial pressure in the change of evaporation as a function of water temperature and air humidity. By the way, this is physics not chemistry.

Second, I am not sure what the comments about Kiehl & Trenberth mean. I think the paper I refer to and use as a reference “Earth’s Annual Global Mean Energy Budget” from 1997 is one of the best resources I have seen on the subject. It is better than the 2009 update because it explains how and where the data came from and because the numbers are balanced at all three levels: planet, atmosphere and the surface. The 2009 version has an unbalance at the surface of 0.9 W per meter squared (which I think was intentional to show future warming) and is hard to understand if you have not read the first version. But if a person uses the new numbers in my model, the results change very little. Evaporation latent heat goes up a little from 78 to 80 W per meter squared and surface radiation from 390 to 396.

Third, regarding, my electrical engineering degree, I took a year of separate courses of college chemistry and physics and happen to get 3 A’s in each not to mention the same in a year’s of advanced calculus in grad school. I am not using any chemistry in my global warming work, but I am with regard to physics. I still have the excellent textbook that has several chapters on heat including partial pressure of water vapor, latent heat and humidity calculations. And in my retirement, I have spent the last 6 years doing literature research and my own computer calculations on CO2 and the feedbacks and how they relate to global warming. As far as engineers go as opposed to “scientists”, we like to solve problems in the simplest, practical, yet sound way, and not spend a lifetime on the same subject. I think the climate people made a major mistake many years ago in dropping improving the simple energy balance models in favor of the complex, bottoms up across the planet for the next 100 years approach, while thinking they could accurately simulate the complex non linear, chaotic climate system just to tell us how much doubling CO2 would warm the average temperature across the globe. Industry would never attack a problem this way. On the other hand maybe they wanted to make things extra complicated so outsiders could not question their work. And it’s not a bad gig. Only your buddies understand what you are really doing and it will take 15, 20 or more years before anyone knows if you are close to the correct answer. Then one can make up excuses. Plus all that government funding while you are helping save the planet. Real “science” in action. And now these same people who can’t even get close to the warming from CO2 are trying to tell how many ways this little warming, they did not predict, will “disrupt the planet”. It’s time for a little common sense. Not even an engineering degree needed to figure this out, and I think the public has. Hopefully, finally the media will too.

82. I will try to cover a number of additional comments and questions here

Bob Shapiro says:
April 15, 2014 at 7:12 am
“Either I’m confused, or several commenters are confused (or both).
The article assumes a constant relative humidity, so the evaporation would need to be greater and would cause more water to STAY in the atmosphere. This water cannot then cause surface reheating by additional rainfall because by definition it is staying up there. (This doesn’t mean the water cycle can’t go up or down separately, just not with this water. BTW, alarmists need to demonstrate water cycle changes using data and not models.)
So the net effect of 6% more evaporation per degree C, is a negative feedback which isn’t being caught by the GCMs.
If I’m wrong, please tell me. Thanks.

Minor point re the acceleration of the water cycle – there can be a great deal of condensation on the water at night without ‘precipitation’ and it goes unnoticed. In other words the argument that the 6% increase is ‘too much’ should be examined in the light of all routes for returning water vapour to the sea.”

My Response:
It is well known that warmer air tends to hold more water vapor, how much is in question. The climate models assume or estimate that relative humidity (the fraction of the saturated value) will remain “approximately” constant. Data shows it actually drops a little, but I want to use the climate model’s values. Less humidity will cause a greater increase in evaporation with temperature, so I am being conservative. One the water vapor increase to what ever level it seeks, than additional evaporation will force increased cloud formation and then precipitation. In the long run of a few months, it is generally agreed that the average will equal evaporation. It has been estimated that a particular water vapor molecule only stays in the atmosphere from about 7 to 30 days. And precipitation reduce the humidity locally with dry downdrafts to help increase evaporation. Regarding the condensation at nighttime that does occur as you point out, that is already estimated in the present net value of about 78 to 80 Watts per square meter average globally. We just assume it will increase in the same proportion that the evaporation will increase, which seems a reasonable.

Greg Goodman says:
April 15, 2014 at 8:12 am
“Several people have pointed out that you can’t heat a ventilated body of water with IR. It simple increases evaporation. Unless I’ve missed by scanning the article too quickly this does not seem to be accounted for.”

My Response:
I do not believe this. While it will increase the evaporation, but only after first warming it. What’s special about IR heating. My microwave warms my coffee and some may evaporate.

Matthew R Marler says:
April 15, 2014 at 1:52 pm
“reg Goodman: Several people have pointed out that you can’t heat a ventilated body of water with IR. It simple increases evaporation. Unless I’ve missed by scanning the article too quickly this does not seem to be accounted for.
Do you have references for that? I may have asked before and missed the answer; if so, I apologize.”

My Response: See comments above on same subject.

george e. smith says:
April 15, 2014 at 1:03 pm
“Well I am not a believer; but I applaud Richard’s effort.
It’s the latent heat; his G that bothers me.
Please stop saying that latent heat warms the atmosphere; it doesn’t.”

My response:
The latent heat warms the atmosphere, but only after it is turned into sensible heat when clouds form. I took it for granted that this was well understood. Thanks for pointing that out. Technically, it is not latent heat any more, but the process of converting it into a liquid during cloud formation releases the heat. This is how an air conditioner works. Except the heat is just moved outside your house. A person can feel it leaving the condenser. With the planet, this is nature’s air conditioning system. The big difference is that the energy to run it is free. It comes from the sum. And the heat is “pumped” upwards by heat rising in the atmosphere because of the temperature drop with altitude until its cold enough to reach the dew point. And part of this warming migrates further upward and increases the radiation to outer space, a cooling action and negative feedback. And the warmer atmosphere radiates the rest of the added heat back to the surface (the atmosphere can’t store heat) which offsets part of the cooling and restores the energy balance needed for evaporation. The value, k, in my equation (3) provides the fraction of the added heat that leaves in the upward direction.

Matthew R Marler says:
April 15, 2014 at 1:52 pm
“reg Goodman: Several people have pointed out that you can’t heat a ventilated body of water with IR. It simple increases evaporation. Unless I’ve missed by scanning the article too quickly this does not seem to be accounted for.
Do you have references for that? I may have asked before and missed the answer; if so, I apologize.”

See comments above on same subject.

Matthew R Marler says:
April 15, 2014 at 2:05 pm
“Richard J. Petschauer,
That was a most illuminating post. Thank you.
I look forward to your response to RACookPE1978; addressing the distribution of temperatures, radiant fluxes, and evaporative changes, rather than calculations based spatio-temporal distributions. However, I think the main point that the GCMs are off is likely to withstand scrutiny.
Is your work available in pdf format? I can easily copy/paste, but I always fear (this may seem absurd) transcription errors.”

My Response: I plan to address RACookPE1978 later. Short answer: The globe and weather system have a good way of averaging these things out as we exprect they will continue to do so.

****
I JUST MADE A PDF of the paper with a few added clarifications one page 1.
FOR A COPY EMAIL TO: rjpetsch@aol.com
****
Janice Moore says:
April 15, 2014 at 3:21 pm
. . . .
“{Note: THE FOLLOWING IS A BONA FIDE QUESTION about the above article — please, if you have the time to explain to a non-tech like I, I would really like to read your explanation. If it is a poorly worded question, please re-word and answer the more useful one. Thanks!}
Question:
Given the above quotes and also this fact: there is no evidence that CO2 causes temperature increases in an open system like the earth,
can Petschauer accurately and with a meaningful level of confidence assert this: “… latent energy for evaporation comes from the temperature of the water itself. … reduced net energy from increased CO2 still warms the surface, … .”
{bolding is to emphasize what I am asking about, here, affect on earth’s climate zones of CO2}
In a highly controlled laboratory experiment, okay. But, on WHAT PROOF, i.e., what MECHANISM, does he base this grand assertion about CO2 and the oceans of the earth?”

My Response: Yes, there is no proof by actual data that mode CO2 will cause the planet to warm. But I have seen what is reported to be satellite data that shows a drop in infrared heat leaving the planet in the same 12 to 18 micron range where CO2 has been shown to absorb and radiate heat. And more CO2 will reduce the heat more in this region according to well established spectral physics. I have run these myself, but they show only about a drop of 2.53 W per square meter for a doubling of CO2, not the 3.7 generally accepted value.

(A stratospheric correction could increase my estimate to about 2.9). The band of CO2 is partial saturated so the heat loss turns out to follow a slow logarithmic function which means each doubling (or any percent increase) will cause the same amount of heat loss. The question is how much the surface temperature will rise per Watt per meter squared of addition heat loss to space. More heat loss will cause the atmosphere to warm enough to increase the heat enough to offset the loss and this warmer atmosphere will reduce the heat from the surface, causing it to warm. The IPCCs and many others divide the 3.7 by 3.2 (or multiply it by about 0.315) to get 1.16 C rise before certain feedbacks alert this. My model’s equation (3) gives me about 0.264 C / per Watt or 2.9 x 0.264 or about only 0.77 C before any feedbacks, which I estimate are much less than the IPCC’s.

No real proof, only estimates but with some good basis I think. By the way, at current annual growth rates of CO2 in the atmosphere of about 0.54% (based on data) it will take about 130 years to double. I think the climate models still use 1%, which gives 70 years. The 1% number ignores the absorption of the CO2 by the planet. This absorption also means the added CO2 will not stay in the atmosphere for over 1000 years as often quouted, if we ever reduce the CO2 emissions.

Richard Petschauer says:
April 16, 2014 at 9:13 pm
———————————–
Richard,
in looking at issues of evaporation, you are looking in the right area. Oceans cover 71% of the planet’s surface and evaporation is their primary cooling mechanism.

The approach you are using seems overly complex , in that you are trying to model the water cycle and then test what altered levels of radiative gases may do.

There are far simpler questions that can be asked as a “sanity check”.

The first of these is –
“given 1 bar atmospheric pressure, is the net effect of our radiative atmosphere over the oceans warming or cooling?”

Or you could ask –
“How hot would our oceans get in the absence of DWLWIR and atmospheric cooling?”

Or you could ask –
“could a non-radiative atmosphere cool our oceans, as it would have no effective means of cooling itself?”

I would note here that the “basic physics” of the “settled science” claims that DWLWIR is warming our oceans from -18C to 15C. Some climastrologists go so far as to claim that -18C is for the “surface” without an atmosphere. Given that the primary cooling mechanism for 71% of the planet’s surface is evaporation, do their claims pass the most basic “sanity check”?

84. george e. smith says:

“””””….george e. smith says:
April 15, 2014 at 1:03 pm
“Well I am not a believer; but I applaud Richard’s effort.
It’s the latent heat; his G that bothers me.
Please stop saying that latent heat warms the atmosphere; it doesn’t.”

My response:
The latent heat warms the atmosphere, but only after it is turned into sensible heat when clouds form. I took it for granted that this was well understood. Thanks for pointing that out. Technically, it is not latent heat any more, but the process of converting it into a liquid during cloud formation releases the heat. …..

Well my response is that NO latent heat energy becomes available from water vapor, until the surrounding atmosphere drops down to the dew point, at which time, given any kind of substrate to nucleate on, the COLDER atmosphere can start removing the energy necessary to allow the phase change to the liquid phase to occur. At no time during liquefaction, does the local Temperature EVER increase, due to the condensation process going on, and if it did then the condensation would stop due to the second law of thermodynamics, not permitting “heat” to flow unaided from a cold source (the water vapor) to a hot sink; aka your warmed up atmosphere.

The transport of the latent heat energy out of the atmosphere is by way of conduction or convection to EVEN COLDER layers of air at higher altitudes. No air ever gets a higher Temperature from latent heat of condensation.

A refrigerator gets rid of “heat” energy by compressing the working fluid which makes it hotter, and then the fluid is cooled by running it through a radiator which is cooled by outside air,

There is NO latent heat involvement, in Cooling the refrigerant by the outside radiator. Automobile engines get rid of “heat” energy by the exact same process, as does a refrigerator; y air cooling of a hot radiator.

85. I am sorry George, we disagree on the role transfer of latent heat throught change of state. Do you believe in cooling by evaporation? If so, it makes sense to think that the reverse process applies. Otherwise we have no conservation of energy.

86. RACookPE1978 says:
“April 15, 2014 at 7:07 am
Thank you for your efforts.
But – and you knew a “but” was coming didn’t you? 8<)
If we start with balance at the surface and again solve for G, we get the same result that also forces balance at the atmosphere.
Does that not "require" the usual assumption of a single flat-earth, flat-plate, one-sided, "average' earth at a single constant distance from the sun in a "perfect" equilibrium" with space?
Rather, how does your work change if you require the use of a "spotlight" solar heating on a rotating 24 hour sphere? Solar heating is NOT an uniform average of 324 watts over 24 hours, but is a constantly-changing value between 200 watts (at 07:00) to over 1150 watts (noon) to 0 (after dark, before sunrise.)
Today, for example, day-of-year 105 (15 April) the amount of solar energy on each square meter of the earth's surface at the equator each hour of the day on a clear day is NOT 324 watts, but the following:
01:00 0
03:00 0
05:00 0
07:00 184
09:00 747
11:00 1087
12:00 1131
13:00 1087
15:00 747
17:00 184
19:00 0
21:00 0
23:00 0
So, your “equilibrium model” must evaporate, radiate (long wave), convect, and conduct (from the upper 2 millimeters of water to the depths), not 342, but 1131 watts (at the equator, at noon.) But, over night, an adequate model must change to evaporate, long wave radiate, convect, and conduct 0.0 SW solar radiation, and cool the ocean using the available stored energy from the previous day.
But the earth at any latitude is not radiated evenly either, and the north-south distribution invalidates a simplified flat-plate radiated evenly at equilibrium mode as well. Same day-of-year as above, same one square meter flat surface at noon as above, same clear skies in direct sunlight as above, but at each latitude.
+85 178
+80 278
+70.6 467 (Southern Edge of 2012 Arctic Sea Ice this doy)
+70 479
+67.5 527 (Arctic Circle)
+60 666
+50 830
+40 965
+30 1065
+23.5 1110 (Tropic)
+20 1127
+10 1150
000 1131 (Equator)
-10 1073
-20 977
-23.5 935 (Tropic)
-30 846
-40 684
-50 499
-60 299
-64.4 211 (Northern Edge of 2011-2013 Antarctic sea ice extents this doy)
-67.5 150 (Antarctic Circle)
-70 104
-80 0
-85 0 "

My response:
You provide a lot of data thatr I assume is correct. But the earth and atmosphere stores a lot of heat and the atmosphere and oceans to some extent move it from heat to cold places

Here are some examples:
I live in the Minneapolis area, very close to the 45% latitude.
On June 21 with the most sunlight, the ratio to day and night solar radiation is infinite. But the difference between the average high (81) and low (61) is only 20F. These values convert to 300.4 and 289.6 degrees K. Using the Stefan-Botzmann radiation equation, W = 5.670e-8 T^4, one get radiations of about 461 and 396 Watts per square meter, a difference of only 16%.

Looking at winter vs, summer and using June and December, the hours per day of sunlight drops from about 16 to 8 hours per day. Beside this, the sun’s angle at noon goes from to 65 to 22 degrees. Using the ratios of the hours and the sine of these two angles gives a combined ratio of (16 x 0.907) / (8 x 0.374) or 4.85 to 1. This ignores the cooling effect of the reflection from winter snow that would increase the ratio. The average daily temperature drops from 71 to 13 F. This gives radiations of about 427 and 269 Watts per square meter, a ratio of 1.59 compared to a ratio of heat from the sun of 4.85.

Now lets look at different latidues. Comparing the tropical atmosphere with a latitude of 15 degrees with the mid latitude of 45 degrees, the data I have show an average annual surface temperatures of 299.7 K and 283.2. Using the cosine of the angles, the ratio 0.966 and 0.707 is 1.37. The radiations are 442 and 365, a ratio of 1.21. So here we get less difference, but some heat is indicated in moving from the warmer climates to the colder ones.

I never said my model requires that the earth is flat. Only that there is an average global values of heat transfers between the three levels and outer space and the only way heat can move in or out of the planet is by radiation to/from space. There is some non-linearity between radiation and temperature, but not much. For example at 15C, the radiation is 390.1 Watts per square meter while the average of 5C and 25C is 392.9, a difference of only 0.7%.

87. Matthew R Marler says:
April 15, 2014 at 5:47 pm

“I have posed the question: If doubling CO2 increases downwelling LWIR by 3.7 W/m^2, how much of the energy transfer goes to warming the water and near-surface air, and how much goes to vaporizing the water (in the non-dry parts of the Earth surface)? His calculations and your calculations suggest that most has to go to vaporizing the water, and little to temperature increase.”

My Response:
You can get similar information from Table 1 by comparing cases 2 and 3 where all the details are shown. Case 2 has a temperature rise of 2.7C from the 10 Watts per square meter at the top of the atmosphere (IPCC claims about this much starting with 3.7 if you include their feedback multipliers). This case has no change in evaporation. G (surface radiation) goes up from 390 to 404.85, an increase of 14.85 (all values in Watts per square meter). (14.85 is larger than 10 because of the “greenhouse multiplier”). For case 3 with 6% rise in evaporation / C, the temperature rise drops from 2.7 C to 1.57 C, and G goes down to 398.57 a decrease of 6.28 from the 404.85 value. The evaporation (E) goes up from 78 to 85.4 a gain of 7.40. So where does this energy gain of 7.40 – 6.28 or 1.12 come from? Look at the change in D, the down radiation from the atmosphere. It increased from the latent heat condensing and increased from 338.85 to 339.97 or 1.12, exactly matching increase in heat leaving the planet. These numbers were not fudged, but came directly from equations (4) through (8). And the “In minus Out” numbers shown under the table show that all energy balances at all the three levels are maintained. For a 3.7 W per meter squared change, just scale these numbers by 3.7 / 10 or 0.37.

By the way the evaporation latent heat did not increase 6% / C from the original 2.7 C of warming. This seems to be a major confusion point, although the paper mentions this in three places. The 6% increase is from the reduced rise of 1.57 after the cooling action. For case 3, 1.57 x 0.06 x 78 = 7.34. The table shows an increase of 78 to 85.4 or 7.4, a slight difference from nonlinearities.

88. Dr. Strangelove says:
April 15, 2014 at 6:47 pm
“You get 6%/C if relative humidity remains constant. But it will decrease because evaporation cools the water. So water temperature drops as well as its vapor pressure. But air remains warm and its absolute humidity at saturation point increases with temperature. You get initial increase in evaporation then decrease. You average the two. 6%/C if only increase and no decrease.”

My Response:
But moist air rises since H2O has a molecular weight of 18 compared to air at about 29. And the cooler water is denser so it sinks. Both of these refresh the surface at the interface even when there is no wind and/or wave action, which usually exist, and accelerate this. Perhaps there is some small drop as you describe. I use 6% since there is some date to support this and the calculated value for constant RH is about 6.5%. Also, I just discovered data by Dai (2006) from over 15,000 stations from 1975 to 2005 that shows on a global basis humidity increases 5% / C, indicating a drop in RH from about 70% to about 69%. This slight change increases evaporation rate to 10% / C. Details: vapor pressure at 17 C = 19.36 mbar; at 18C, 20.63. So (20.63 – 20.63 x 0.69) / (19.36 – 0.7 x 19.36) = 1.10. At a typical 70% humidity, small changes in RH make a big difference. I think the IPCC considers a drop from 70% to 69% as still being “consistent with” constant RH. Repeating the calculation at 50% humidity, a drop to 49% for a 1 C rise gives an increase in evaporation of 8.7% / C. So my 6% seems conservative.

Curious George says:
April 15, 2014 at 8:15 pm
“There is an excellent reason why at least one IPCC model (CAM5) has a problem with evaporation: it treats a latent heat of water evaporation as a constant, independent of temperature (in reality, it is 3% lower at 30 C than at 0 C) – http://judithcurry.com/2013/06/28/open-thread-weekend-23/#comment-338257. Modelers take it philosophically: why should a latent heat, of all things, be treated correctly?:

My Response:
I looked at that. It seems they are referring to the latent heat per kg of weight. This varies a little with temperature. My physics book shows for water it drops from 595.4 to 538.7 calories per gram when the temperature increases from 0 to 100 C. That is only a change of about 0.1% per C, which is not a large concern it seems.

Terry says:
April 15, 2014 at 9:46 pm
Richard Petschauer
In your analysis you hold H as a constant. How realistic is that. Also your calcs indicate that for an increase in E there is no increase in U. Surely U must increase with an increase in E and H that both result from the increase in evaporation, and it is U that is actually important since it is the only pathway for the evaporative losses to escape the system.

My Response:
If H varies, that should be treated as a separate feedback. One would need to know how much it changes per C of surface temperature change. Then use the same method as for E. In fact you could scale it from the feedback factor of –0.741 for a 0.06 x 78 or 4.68 Watts per square meter. This would be additional negative feedback that combines with others algebraically. It is probably not much since the atmosphere temp will increase with the surface.

Regarding the increase in U, it is small because for both the cases with and without changes in evaporation, E, the forcing at the to of the atmosphere is constant at 10 W per meter squared. Note in all cases after the climate warms to offset the 10 w loss to outer space (which our model provides), the sum of U and W, (the amount through the atmospheric window that goes directly from the surface to outer space) always total 235, the net incoming solar after the reflections from clouds and the surface. W varies with G as shown in equation (6) in the paper.

bobl says:
April 15, 2014 at 10:54 pm
“Richard Petschauer,
Let me paraphrase, in order to avoid energy limitation arguments, you have used an assumption of available driving energy of 10W / square meter, not caring where it comes from.
The point I’m trying to make though is that in reality we energy constrained. We are told that a doubling of CO2 produces a driving energy of 3.7W per meter squared not 10W. What I was wanting you to do was to constrain your solution to 3.7 watts and calculate the maximum temperature change, and evaporation when that constraint is applied, or alternately calculate the energy required for an increase of 1C given that evaporation increases 6 % either way this makes for a quick comparison with IPCC models. I am not suggesting that the energy constraint would reduce the evaporation.
Eg the IPCC says that a doubling will cause 3.3 degrees of warming and by your calcs an attendant 20% increase in evaporation. Given that the energy is constrained to 3.7 Watts per square meter what is the revised temperature rise and evaporation rate. I’d assume that if we calculated the maximum extra evaporation that could be sustained by the excess energy, one could use the temperature/evaporation relation to tell us the temperature rise, all other losses ignored. By my estimate rather than 3.3 degrees and 20% we would get about 0.5 C temperature rise, and 3% evaporation for a doubling. That’s a big difference, a headline.”

I think you understand it. The 6% / C applies after the final temperature change. The 3 C rise will not stand, but I don’t get as low as 0.5 C that you do. My case # 3 is close to what I get, ignoring other feedbacks which I as a rough estimate include in the 10 W forcing which was to represent the 3.7 multiplied by the IPCC or climate models feedbacks. For 10 W they 10/32 or 3.125 C. My model ignoring evaporation changes gets 2.7 C. That is case 2 in my Table 1. With evaporation increased to 6% per C (case 3), the rise drops to 1.57 C. A breakdown of the energy transfers follows.

In case 2 with no change in evaporation, G (surface radiation) goes up from 390 to 404.85, an increase of 14.85 (all values in Watts per square meter). (14.85 is larger than 10 because of the “greenhouse multiplier”). For case 3 with 6% rise in evaporation / C, the temperature rise drops from 2.7 C to 1.57 C, and G goes down to 398.57 a decrease of 6.28 from the 404.85 value. The evaporation (E) goes up from 78 to 85.4 a gain of 7.40. So where does this small energy gain of 7.40 – 6.28 or 1.12 come from? Look at the change in D, the down radiation from the atmosphere. It increased from the latent heat condensing and increased from 338.85 to 339.97 or 1.12, exactly matching increase in heat leaving the planet. These numbers were not fudged, but came directly from equations (4) through (8). And the “In minus Out” numbers shown under the table show that all energy balances at all the three levels are maintained. For a 3.7 W per meter squared change, just scale these numbers by 3.7 / 10 or 0.37.

By the way the evaporation latent heat did not increase 6% / C from the original 2.7 C of warming. This seems to be a major confusion point although the paper mentions this in three places, but you seem to understand this. The 6% increase is from the reduced rise of 1.57 after the cooling action. For case 3, 1.57 x 0.06 x 78 = 7.34. The table shows an increase of 78 to 85.4 or 7.4, slight difference from nonlinearities.

By the way, while 10 W forcing is intended to include the approximate added forcing from the positive feedback multipliers, the correct way is to include sum the feedbacks
and create a single feedback multiplier. The negative feedbacks have a large effect then in offsetting the positive. For example a positive feedback of 0.5 and a negative feedback of 0.5 cancel each other out. However, the positive feedback multiplier is 1 /( 1 – 0.5 ) or 2 while the negative one is 1 / ( 1 – (-0.5)) or 1 / 1.5 or 0.67. But 2 x 0.67 give a feedback multiplier of 1.33, not the correct value of 1. That is why in my paper, I show the drop in the feedback factor from 2.48 down to 0.91. For a 3.7 W my model fives a temp rise before feedback of 0.98 C (others and the IPC get about 1.15 C). So for a final with no changes except in those in the paper, I get 0.98 x 0.0.91 or 0.89 C.

Now I am in the process of using the Hitran spectral absorption database and my energy balance to estimate water vapor feedback now estimated at 1.8 W per square meter which is a feedback factor of +0.5625 C / C.

I also have published a paper with much detail on estimating if the 3.7 w forcing for 2 x CO2 is correct. (See:http://climateclash.com/does-the-tropopause-limit-carbon-dioxide-heat-trapping/). It shows only 3.38 that drops to an average 2.53 when typical clouds are included. However, the paper does not include a stratosphere cooling correction that is supposed to be included. Adding 15% for this gives a value of 2.9 W, still less than the 3.7 now widely accepted. Replacing the 3.7 with 2.9, I get after feedback a temperature rise of 0.70 C from doubling CO2 .

89. Curious George says:

@Richard Petschauer April 17, 2014 at 1:40 pm: “That is only a change of about 0.1% per C, which is not a large concern it seems.” I agree with your numbers, not with your easy dismissal. At 30 degrees C (the highest surface temperature of tropical seas) the latent heat is 3% lower. That means that with the same supply of energy the model will evaporate 97 kg of water instead of correct 100 kg. Clouds can only form when a relative humidity reaches 100%, so the model will underestimate clouds.

90. Curious George says:

.. and of course it will also underestimate the effect of water on IR radiation.

91. Reply to Curious George from
April 17, 2014 at 7:02 pm

The 0.1% should apply to the difference in the average global temperatire of 15C and 30C, so it is about half of what you estimate or 1,5%. Also this was based of the differences of radiation that go as the 4th power of the absolute temperature. But all this is already happening. I was concerned with changes from one surface temperature to another. Also if my estimate of evaporation increase is only 1.5% less than 6%, or 5.91% that is not too bad.