Guest Post by Willis Eschenbach
As usual, there is more to learn in the CERES satellite dataset. I got to thinking of the idea put forth by Lacis 2010. He announced model results claiming that if the only modeled greenhouse gas in the modeled atmosphere were modeled water, the model world would basically evolve to a modeled ice over condition at a modeled -20°C (-4°F). Here is his money graph, showing the evolution of various modeled climate measurements in the first fifty modeled years after removing all modeled GHGs except for modeled water from the modeled atmosphere. See his paper for details.
Hmmm, sez I … something there doesn’t look right. The modeled planet is frozen solid at -20°C? (black line) … Don’t think so. Oddities.
Now, planetary albedo is what percent of the sunshine is simply reflected back into space. Currently it’s around 30% (orange line, left end, right scale). But how can the planetary albedo be going up in his results by a third, while at the same time the atmospheric water content is reducing by 90%?
Globally the albedo is ruled by clouds. You’d think the variable sea ice and snow on land during winter would matter more to the albedo. But consider how much sunlight there is during a polar winter … the albedo is high up north because of ice and snow, but the weak winter sun may not even come up over the horizon. As a result, ice doesn’t affect the total planetary albedo as much as you might think, much less than clouds, simply because it’s generally not reflecting much sunshine.
So how could albedo be going up when the amount of water in the atmosphere was going through the floor? My intuition, my bad number detector going Hmmm, said no way it could do that—but I realized I didn’t really know that.
So I thought I’d take a look at the data. Remote Sensing Systems (RSS) publishes a gridded dataset of total precipitable water over the ocean. It’s available here as a 3-D NetCDF file (lat/long/time). So I compared that measurement of atmospheric water to the measured albedo of the CERES dataset. The result is below, showing the correlation of total precipitable water (TPW) and total albedo (surface plus cloud). The monthly seasonal variations were removed from the data before analysis. This is the correlation of 17 years of data.
I can’t tell you how much fun it is after laboriously writing the computer code designed to create a new result, hitting run … and then waiting for the image to appear. It’s always a surprise and a joy, new understanding, new intuitions. But I digress …
As you can see, indeed the general pattern is, more water = greater albedo. There are only limited areas of exception to that. This correlation is strongest in the western tropical Pacific, where the ocean is warmest.
So I have to doubt the Lacis result simultaneously claiming much less water and yet greater albedo. Less water = less clouds = less albedo, not more as Lacis claimed.
My next objection to the Lacis result is the precipitous drop in surface temperature. Presumably inter alia it is a result of the great reduction in incoming sunshine due to the fantasized albedo increase. But as shown in the figure above, less water in the air = small albedo, not larger as Lacis claims.
Nor is the temperature drop a result of the loss of atmospheric longwave absorption due to the poorly-named “greenhouse gases” in the atmosphere. There’s an amazing on-line line-by-line atmospheric calculator called MODTRAN. And according to MODTRAN, the loss of all of the GHGs except water would cool the planet by from 6°C to 8°C, with the smaller value in subarctic winter and the larger in the tropics. This is far from enough to take the global average down to minus twenty as claimed.
In addition, there are larger forces at play. Let’s consider three inter-related measurements—ocean sea surface temperature (SST), total precipitable water (TPW), and albedo. All of them rise and fall together. The warmer the sea surface is, the more water there is in the atmosphere, because evaporation increases with temperature.
The warmer the SST, the more water in the atmosphere, the more clouds. The more clouds, the greater the albedo.
Now, think about the effect as this relationship unfolds over time. Warmer ocean waters lead to more atmospheric water leading to greater albedo, which results in less sunshine making it to the surface … which results in cooler ocean waters …
Or we can look at it the other way. Cooler ocean waters lead to less atmospheric water leading to lower albedo, which leads to more sunshine making it to the surface … which results in warmer ocean waters …
How about that for a lovely thermostatic phenomenon? Cools the ocean when it’s warm, warms the ocean when it’s cool!
And that’s the main reason I disbelieve the Lacis model result claiming that the world will go to -20°C. The world is full of many such emergent phenomena that all tend to stabilize the surface temperature. The temperature is not some slavish linear function of the forcing as is generally claimed. It’s far more complex than that.
Best to all on a foggy afternoon. Feel free to come over to my blog or follow me on twitter @WEschenbach
w.
PS—Misunderstandings are the bane of the web. Please QUOTE THE EXACT WORDS you are referring to, so we can all understand both who and what you are talking about.
w. ==> I would have predicted the Lacis result, or something similar, from Chaos Theory alone. Fiddling with the numeric climate models, dependent on non-linear equations, is very likely to throw the “future climate” (chaotic model output) into one or the other of the two known possible climate extremes, and leave it trapped there. This is very easily demonstrated with any of the common examples of non-linear formula output.
This does not happen in the Real World, of course. It only happens in numeric climate models, as accidentally discovered by Edward Lorenz long ago.
The Real World climate does occasionally stray to extremes but eventually recovers from the extreme and we have an Interglacial period., as we do now.
My jaw drops every time I look at the Lacis 2010 paper. A 90% reduction in column water vapor leads to a large increase in cloud cover? Wouldn’t that ridiculous result cause anyone with sense to go back and question their analysis?
It’s called the Clausius-Clapeyron relation coupled with condensation and a stratification of the boundary layer due to surface cooling.
It’s total BS. What ends interglacial warming of a steady 0.001 deg K pa for 7Ka, while CO2 from the oceans is still accelerating to a maximum, with NO effect on the temperature shut down at this point in the cycle? Why didn’t it warm a lot more when humans nearly doubled the CO2, with an actual maximum 0.3% sensitivity re absolute temperature over the same period – if CO2 was all the cause. RUBBISH.
ANSWER? Cloud control. GHE warming from water vapour is small vs other cooling effects , only impactful during the stable ice age cold periods of low humidity, temperature hence cloud cover. GHE water vapour effect kis useful to keep things above freezing at this time, but insignificant in precipitous (0.001 deg K pa) interglacial peak temperature and humidity events. NB: Nothing changes at more than noise levels in human lifetimes. FACT.
Under iterglacial conditions Water Vapour has over 140W/m^2 of negative feedback to warming available – from 90w/m^2 evaporation, cloud formation and precipitation, and 50W/m^2 of cloud albedo , a tiny variation can crush all the GHE from CO2, for example.
Of course this virtual reality is nonsense, as any fool knows, except the so called climate scientists. They look at the climate big picture through IPCC virtual reality modellers goggles that have gone beyond the physical limits of deterministic science, to eschew a trust in actual data in favour of their beliefs and prophesies. In short, they believe their own bullshit, like the papal forgiveness salesmen they are.
I can see NASA at the Challenger enquiry, as Feynman elegantly demonstrated the physical reality of their deceitful assertions with some ice water and a clamp. Nothing much has changed in the management team or their preference for their own opinions over the actual facts, IMO.
Time for a repeat demonstration of reality to law makers as regards NASA et al, this time re climate? But who can do this? Once the regressive and truly fraudulent on the absolute energy science fact energy subsidies disappear, then the grants to prove a position that support the subsidies will disappear with them, the BS dies along with the easy money subsidies that fill the renewable energy trough for the cynical insiders, be they academics, politicians or renewable lobbyists.
And another thing…. is this a very revealing demonstration of how wrong the underlying model assumptions are?
I am no expert on computer model prophesies, I prefer Feyman’s idea of deterministic physics that follows laws to the pseudo science prediction by extrapolation of correlation without proof. Neural nets are not science. And unsafe outside their data limits. As AI will be. And cliate models, IMO.
Does Lacis simply remove the dreaded killer AGW gasses from the IPCC default climate model to arrive at this history denying conclusion?
If so, comparing the outcome of his virtual reality model with the actuality of a low CO2 interglacial, for example, seems to demonstrate rather neatly just how much the GHE effect from trace gasses is over amplified in the models, when compared to the inconvenient truths of the climate record. Not also might this underestimate the actual effect of water vapor, but it may also show many other potentially significant effects may be artificially inhibited in their effect by modeller’s assumptions, designed to make make their chosen causes appear the main contributors to warming, as per the terms of their grants.
Or perhaps I over simplify 😉 ?
A bigger or different model is not the answer. Some deterministic reality is. Regarding both climate unknowns and energy reality. Is it yet time to call BS on the whole renewable subsidy racket and the pseudo science of computerised rune casting behind it? It’s frauds are busting out all over.
Willis. Excellent discovery. For the data to extend it to land, might NOAA’s Precipitable Water (over land) – help? https://sos.noaa.gov/datasets/precipitable-water-over-land-real-time/
Thanks, David. Sadly, all I could find at that site were their graphics. It’s a great dataset, daily, but only images … anyone know where the data for this might be available
w.
Willis FYI a paper on clouds and Total Precipitable Water
Method for observation of total atmosphere vapor over Inner Mongolia with MODIS data
http://en.cnki.com.cn/Article_en/CJFDTOTAL-GHZH200905014.htm
To extend over land, this may be of interest. Evaluation of atmospheric precipitable water from reanalysis products using homogenized radiosonde observations over China
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2015JD023906
“And according to MODTRAN, the loss of all of the GHGs except water would cool the planet by from 6°C to 8°C, with the smaller value in subarctic winter and the larger in the tropics.”
Good to have that confirmed, I have heard claims of the larger value in subarctic winter and the smaller value in the tropics.
The snowball earth hypothesis, (probably wrong) holds that Earth was completely covered in ice and snow (yes right down to the equator) about 700 million years ago.
What was the atmospheric make-up back then? How much CO2? (Oh, nothing, nothing. Why do you ask?)
Oh dear, I think you’ve just proved water vapor is a negative feedback Mr Eschenbach.
The climate cabal is not going to be happy with you…
(PS, nice data!)
Thanks Willis for revisiting Lacis[2010].
Planetary albedo may be much more stable than previously thought. One almost astonishing example of cloud feedback from The albedo of Earth: “The Northern and Southern Hemispheres (NH, SH) reflect the same amount of sunlight within ~ 0.2 W/m2”.
the model world would basically evolve to a modeled ice over condition –>
the model world would basically evolve to a modeled ice cover condition
Willis wrote: The warmer the SST, the more water in the atmosphere, the more clouds. The more clouds, the greater the albedo.
This post shows a correlation between Ts, TPW and cloudiness, but – as we both know – correlation is not causing. Clouds are produced by rising air masses, not temperature or TPW. Rising air masses are produced by an unstable lapse rate and the inability of radiation alone to carry away all of the energy arriving at the surface. For air masses to rise, there must be air masses subsiding elsewhere and subsiding air is always clear (except for marine boundary layer clouds). To a first approximation, one might expect the area occupied by rising and subsiding air masses to remain constant.
Globally cloud cover is about 68%. Over the South Pole, 55% of the sky is cloudy in the summer when the average surface temperature is -25 deg, slightly colder that Lacis’s planet. In the winter, it drops to 35% when the average temperature is -58 degC, almost 40 degC lower than Lacis’s planet. Along the coast (where the temperature is near 0 degC, 75% of the sky is cloudy year round. Cold doesn’t prevent cloud formation – subsidence does.
https://journals.ametsoc.org/doi/10.1175/1520-0442%282004%29017%3C1198%3AACARWT%3E2.0.CO%3B2
You are worrying about a small fraction of the changes that would follow removing CO2 from the atmosphere. The lower the temperature and water vapor, the smaller the greenhouse effect. With all CO2 gone and 90% of the water vapor gone, almost nothing interferes with LWR radiative cooling to space.
According to MODTRAN, with 0 ppm CO2 and 10% normal water vapor, the planet with a US Standard Atmosphere (no clouds) at 288 K would emit 329 W/m2 to space, up 63 W/m2 from the current 268 W/m2 that escapes from clear skies. (The lower emission from cold cloud tops lowers this to 240 W/m2.) Lowering the surface temperature to 281 K (down 7.2 K) lowered OLR to 268 W/m2. So the 90% reduction in water vapor produces a reduce GHE that lowers the temperature 7 K.
The second important factor you haven’t considered is how the height of the cloud tops will change. Low cloud tops radiate almost as much energy as the surface, while high cloud tops at 218 K emit 1/3 as much thermal radiation as the surface. Convection carries water vapor aloft only until the atmosphere is transparent enough so that radiation can remove all the heat delivered to the surface. Lower cloud tops means more effective radiative cooling to space and a lower surface temperature.