Is the climate computable?

chaos_signOur WUWT thread on Antarctic Sea Ice Losses has spurred quite an interesting discussion. Dr. Robert G. Brown of the Physics Department at Duke University responds to a comment on  ice albedo with a summary of water vapor action, the greenhouse effect, and the chaotic nature of the atmosphere. He ends with his view of why he’s not a betting man.

Well worth a read.

rgbatduke says:

May 21, 2014 at 5:49 am

phlogiston: I do realise that over the Antarctic land mass albedo from surface snow is anomalously higher than that from cloud, since the snow presents such a pure white surface. However this is probably not the case for sea ice whose surface is more irregular and cracked with patches of dark sea in between.

The trouble is that water vapor is literally a two-edged sword. As vapor, it is the strongest greenhouse gas in the atmosphere by (IIRC) around an order of magnitude, so increasing water vapor can and does measurably increase the GHE — a lot, when considering dry air versus saturated air. In arid deserts, temperatures skyrocket during the day and plummet at night because of the absence of a water vapor driven GHE — CO_2 alone isn’t nearly enough to keep upward facing surfaces from rapidly losing their heat due to radiation. In very humid tropical climates, the nights are consistently warm because of the GHE.

However, water vapor is also the mediating agent for two major cooling mechanisms. One is the bulk transport of latent heat — sunlight and LWIR hit the sea surface and cause rapid evaporation of surface molecules of water. Wind blows over the ocean surface, stripping off water molecules as it goes. This evaporated water has a huge heat content relative to liquid water — the latent heat of vaporization. As the warm water vapor is carried aloft by convection, it carries the heat along with it. It also cools as it rides the adiabatic lapse rate upward, and further cools by radiating its heat content away (some of which returns to the Earth as GHE back radiation). Eventually the partial pressure of water vapor in the moist air becomes saturated relative to the temperature and the dew point is reached, making it comparatively probable that the water vapor will recondense into water. In order to do so, though, several things have to be “just right”. The water vapor has to be able to lose the latent heat of vaporization that it picked up at the water surface when it evaporated. The future water droplets have to be able to nucleate — which is a lot more likely to occur when there are ionic aerosols in the atmosphere as water (a polar molecule) is attracted to bare charge of either sign.

Once a water droplet is nucleated and grows past a critical size (that depends weakly on humidity and temperature) its surface becomes large enough that growth due to increased surface deposition outweighs loss due to surface evaporation, and the droplet stabilizes as a single droplet of condensation in a cloud or continues to grow to fall as rain. Either way the water, now high in the troposphere and hence through most of the optically opaque greenhouse layer, releases heat that is “short circuited” through the greenhouse mechanism and lost to space via radiation.

The cloud, as you note, has a very high albedo. High albedo means that it strongly reflects short-wave (e.g. visible) radiation without ever absorbing it and being heated by it. During the day, clouds outside of the polar regions act as a cooling agent, reflecting sunlight before it has a chance to reach the ground and lower troposphere to warm either one. During the day and the night, however, the cloud also acts as a powerful greenhouse blanket, directly reflecting LWIR as well as visible back down towards the Earth’s surface. In the tropics, daytime reflection wins by a landslide — reducing the incident sunlight by a huge fraction for a large fraction of the day beats the comparatively small modulation of surface radiative losses both day and night. In the temperate zone (again, IIRC) albedo still wins, but by a smaller and smaller margin as one creeps north (and in ways that are increasingly dependent on seasonal weather patterns — in the winter clouds can easily be net warming where in the summer they can be net cooling).

However — and this is key and the reason I’m replying to you — in the polar regions clouds are generally net warming, at least most of the year. You’ve already indicated some of the reasons — the polar regions are already often or permanently ice covered, and the gain in daytime albedo from clouds vs ice is not so great. The real problem, however, is that nighttime warming from the enhanced GHE from clouds scales with the fraction of the day that it is nighttime, and of course inside the arctic circles that can be as long as 100% of it. High albedo doesn’t cool when there is no incident sunlight to reflect, and even in the arctic summer, the sun comes in at a substantial angle so that direct solar warming is weak (so that clouds can reflect only a proportionally smaller amount of heat). A lot of polar temperature is determined by heat transport, not direct heating, explaining the substantial difference in mean temperatures of the North and South poles. In the north, there is substantial heat transport and heat exchange via the ocean; in central Antarctica there is only the atmosphere to carry heat in from the warmer latitudes and it just can’t do the job half as well.

That’s why I hesitated to assign a sign to the net feedback from any sort of local modulation of e.g. ocean-air humidity or sea ice coverage. The processes are COMPLEX and can have either sign, and they are NON-LOCAL as adding humidity in one place can increase albedo someplace else thousands of miles away is it finally concentrates enough to form clouds. A large part of the rain that falls over North Carolina comes up from the Gulf of Mexico maybe 1000 miles away. Some of it comes all the way over from the Pacific, where some of that might have originated in e.g. the growing El Nino. Heat from the tropical Pacific can be transported all the way to NC before it finally releases its heat and falls as rain, before it finally creates clouds that cause NC to cool after helping to greenhouse warm much of the surface area it crossed in between.

This is the kind of thing that the models are supposedly trying to model, but they perforce replace all of the small-length scale detail of this description with presumptive averages over cells 100-300 km square (where weather phenomena such as thunderstorms are order of 1 to 10 km square, where the details of front structure and development are much finer than this). They are excruciatingly tuned to aerosol levels and albedo — they have to be to stabilize anywhere near the correct/observed temperatures and preserve the central tenet that CO_2 causes X amount of baseline warming that is on average augmented by additional water vapor.

This last assumption is finally dying a quiet and well deserved death. AFAIK, it is due to Hansen, who in his original papers predicting disaster assumed universally positive water vapor feedback (and for no particularly scientifically motivated reason that I can see, hypothesized truly absurd levels of water vapor feedback that doubled or tripled the CO_2-only warming of his then very simple models). Naturally, some of the GCMs out there have built into them parametric assumptions that preserve this much “climate sensitivity” — total ACO_2 warming plus feedback, usually at the expense of an overdriven response to e.g. volcanic aerosols necessary to explain periods of global cooling and to keep the model from having a runaway exponential instability (because one has to have a mechanism that keeps positive feedback water vapor from causing increase of water vapor without bound just from FLUCTUATIONS in water vapor content or global temperature — the climate cannot be a biased random walk where every time the temperature goes up a bit, average water vapor increases and hence resets the Earth’s average temperature a bit higher unless a competing process can completely erase the gain when the temperature fluctuates down a bit).

At the moment, estimates of climate sensitivity are struggling to retain any net positive feedback from water vapor in the face of data that already solidly excludes the kind of absurd feedback levels Hansen originally hypothesized. Even the question of net negative feedback from water vapor, long considered to be anathema in climate science (except for a few mavericks who managed to publish papers suggesting that clouds could easily lead to net negative feedback through the dual mechanism of latent heat transport and modulation of albedo) is no longer completely off of the table. I don’t know that people will start to take it too seriously unless/until the Earth actually cools (several tenths of a degree, sustained, not just vary up or down or weakly downward trend) but obviously if this happened it would truly be the only likely catastrophe associated with global warming to all of those that have invested their professional careers, hundreds of billions of dollars of global wealth, and their political and/or scientific reputation on shaky claims in poor agreement (so far) with observational data.

IF there is a super-ENSO, perhaps it will help their arguments survive a bit longer, or perhaps it will truly kick up the temperature to where the models become believable again. Perhaps not. ENSO is not the only factor in climate evolution, and while it has been dominant for the last half century or so in mediating positive jumps as documented by Bob Tisdale, its ability to do so could easily be predicated by the phases and states of the other decadal oscillations, the state of the Sun, the state of baseline vulcanism, the immediate past climate history, and the price of tea in China. A chaotic nonlinear system can be quasiperiodic and apparently causal for a while and then for no computable reason change to an entirely different mode of behavior where a significant quasiparticle/process becomes insignificant and some other process becomes the critical driver. We could still watch as the developing ENSO discharges all that heat in such a way that it never manages to raise global average temperatures by much because of some confounding wave that causes the heat to be efficiently transported up and quickly lost rather than persisting to spread out over the globe at high altitude, or by a mere modulation of the winds that causes albedo over the warm(ing) patch to be higher than expected so that the delivery of solar energy to the ocean is effectively interrupted. It’s not like we can properly predict ENSO (although we can do pretty well with forward projective hindsight once an ENSO process has started).

No matter what, I expect the next year to be highly informative. If we have a super El Nino that heats the planet by 0.3C very rapidly, that certainly makes GCMs more, not less, plausible on average as it kicks global average temperatures at least in the right direction for them not to be as egregiously wrong as they currently appear to be. If it only kicks the temperature up by 0 to 0.1 C, and that only transiently so that temperature in a year are again pretty much flat relative to 1998-2000, it is very bad news for the models. If it fizzles altogether — short-circuited, perhaps, by the downhill side of solar cycle 24 that maybe be beginning and which will proceed with poorly predictable speed and which may or may not have a competitive local effect on the climate and produces no gain at all and cycles immediately into a cooling La Nina that augments any solar cycle cooling to actually drop global average temperatures, that too will be very informative.

Personally, I won’t even place a bet. I don’t think the climate is computable, which means that I think one is basically betting on the output of a (possibly biased) random number generator. I’d rather play Mumbledy-peg for money.

 

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AlecM

You claim LWIR coming down from the sky; ‘back radiation’. It doesn’t exist; here’s why. IPCC ‘science’ is based on the concept of “Forcing’, net energy transfer to the Earth’s surface by solar SW and atmospheric LW radiation. Standard physics assesses both as the difference of ‘Irradiances’ from ‘Stefan-Boltzmann’ equations. The IPCC does it differently.
The SW emitter is the Sun, 5,500 deg.K. The SW absorber, mainly the surface, is cooler but it still has Irradiance so net SW surface heating rate = (Sigma(F1.T_sun^4 – F2.T_surface^4). Sigma is the S-B constant, F1 and F2 are parameters dependent on clouds etc.,Ts are temperatures. It comes to +160 W/m^2 (mean). For equilibrium, this heat flux transfers to the atmosphere as 97 W/m^2 convection/latent heat, 63 W/m^2 real net IR of which 40 W/m^2 goes to Space.
In standard physics, net LW surface heating equal net LW IR = (Sigma(F3.T_atmosphere^4 – F4.T_surface^4), numerically -63 W/m^2 = (333 W/m^2 – 396 W/m^2). Conservation of energy is: 160 W/m^2 (SW heating) -97 W/m^2 (convection) -63 W/m^2 (net surface LW IR) = 0 W/m^2. As net surface IR emission in main GHG bands is zero, there’s no atmospheric heating from this.
However, IPCC ‘science’ assumes 396 W/m^2 surface LW Irradiance, the ‘black body’ level for 16 deg C, is a real IR flux when in reality it’s the potential flux to a sink at absolute zero. Only 63 W/m^2 is real. They make up the difference by assuming 333 W/m^2 LW Irradiance measured by ‘pyrgeometers’ pointing to the atmosphere provides extra surface heat when standard physics shows for a normal temperature gradient it can’t transfer energy to the surface. This failure to understand their main instrument is a serious scientific mistake.
Adding 97 W/m^2 convection makes 493 W/m^2, 3x real heating, never proved experimentally. They offset 238.5 W/m^2 by falsely applying Kirchhoff’s Law of Radiation to the (semi-transparent) ToA; you can’t do that. The residual c. 60% more heating is, with 3x real GHE, used to purport imaginary ‘positive feedback’. They then use c. 25% extra low level cloud albedo in hindcasting to pretend the sensible heat left after the extra latent heat doesn’t heat the atmosphere above reality.
IPCC ‘science’ is nothing less than science fraud; manipulation of data to purport much more heating than reality. The GHG-absorbed IR component is exaggerated by a factor of 5.1. This scam deceived all but real heat transfer experts, of whom there are few.

That is one of the most cogent statements of why computer climate models cannot be trusted to accurately predict the future. I truly hope the absurd emphasis on CO2 levels finally gets dumped in the really dumb scientific conjecture grave yard. Then maybe we can get on with finding out how Earth’s climate engine works.

Leo Smith

I dunno who you are sir, but please keep writing.
This has to be the best thing ever written this month at least on climate change.
I have one question for you.
Is what we DO know about the behaviour of water water cycle enough, it crudely modelled, to account for all global warming of the late 20h century without the actual need for it to be driven by anything other than the climate mechanism itself?
That is, can we establish some sort of boundary of ‘purely natural variation’ and show that late 20th century warming is within, or outside it?
If within we simply don’t need any other ‘explanation’.
Climate is doing it all by itself….
I dont think such a model needs to actually look at geographical detail: what we need are the major time delays inherent in the heating and cooling of land masses oceans and ice masses. Because it isn’t actually a climate model: it would be a generalised dynamic model incorporating various feedback elements in it with various delays, and the purpose would be to establish what sorts of delays and feedback factors and indeed non linearities would be needed to create a variable climate that broadly matched the historical one.
That is, instead of starting with the premise that climate change is CO2 driven we started with the premise that it’s self-driven.
And showed that that indeed could account for observed variation better than CO2 driven models..

Stephen Richards

I do like your rational posts, Robert, they always make an interesting, cogent and logical read.
Thanks

SMC

“I’d rather play Mumbledy-peg for money.”
I’m assuming you are talking about the ‘Chicken’ variant. (I had to look this up on Wikipedia… What a great game, I think I’ll teach it to my kids.)

milodonharlani

Even some CACA advocates admit that the climate system would adjust to higher CO2 within a millennium or less, as whatever amount of the magic gas humans have added gets taken up by the various sinks of which science understands so little.

Leo Smith

Doug: computer models might in time be reliable forecasters if we knew what to program them with. The problem is to break down the climate into something broader than microscopic level Navier Stokes partial differentials without throwing the baby out.
WE simply do not yet know what is amenable to ‘parameterisation’ and what is not.
Currently the biggest and most popular elephant in the room is clouds.
No one knows yet how to even approximate clouds.

Doug

A very sensible and enlightening article.

I’m wondering what is so maverickish about negative feedback of water, when it has been demonstrated that temperature series tend to behave anti-persistent, which is consitent with overal negative feedback
http://www.aai.ee/~olavi/EE2007-ok.pdf

Alan Watt, Climate Denialist Level 7

Robert:
I’m always happy when you have time to contribute here. Do you by chance have your own blog somewhere?

Eddi Rebel

“In arid deserts, temperatures skyrocket during the day and plummet at night because of the absence of a water vapor driven GHE ”
Why is it hotter during the day without GHE? I thought GHE always warms?

It is very clear that climate is simply not computable by GCMs. For the reasons why see

For a reasonable and transparent estimate of the possible coming cooling based on the 60 and 1000 year quasi- periodicities in the temperature record and using the neutron count and 10 Be record as the best proxy for solar activity see several posts over the last couple of years at
http://climatesense-norpag.blogspot.com

Somebody

On long term, no, it’s not computable: https://www.youtube.com/watch?v=xig3knCjmaE Not even if it’s a way much simpler system.

Rud Istvan

Thanks for pulling this to the forefront. Wrote a much longer and more detailed explanation (basically saying the same thing, plus showing how AR4 used selection bias to hide the inconvenient facts about humidity and clouds RGB points out) in my Arts of Truth book chapter on climate. The humidity+cloud feedback is in essence Willis Eschenbachs thermoregulation hypothesis, itself a generalization of Lindzen’s original adaptive iris hypothesis IMO.
And no supercomputer in the foreseeable future will be able to model at grid scales small enough to resolve the essential convection cells at the core of the mechanism. That makes climate fundamentally noncomputable using finite element methods, independent of the nonlinear dependencies that make it formally, mathematically chaotic.
Great post. Should be cleaned up (decontextualized) and then spread far and wide.

mellyrn

Nice question, Leo Smith, but, again, not really answerable, I think.
For >75% of its existence, Earth has been -substantially- warmer than it is now — warmer as in, too warm for polar ice caps. Only for less than 1 billion of the last 4 billion years (and not all in one go, mind you) has Earth been as -cold- as it is now, at least according to the rocks.
Your question rather suggests that the current cold is normal, and asks if it is “within purely natural” variation, as if the “late 20thc warming” -might- have an unnatural — anthropogenic — component.
MY question is, what caused Earth to become abnormally cold, as it is now? And when will it -return- -to- -normal-? Because an Earth warm enough for forests in Antarctica IS “normal” — geologically speaking. If we were to shut down all our industry, the polar ice sheets would melt away anyway. Eventually. And quite naturally.

Eustace Cranch

Thank you Dr. Brown. This is fascinating and extremely informative. Some of the best climate info I’ve read all year
This piece in particular strikes me as spot on, and hugely important:
A chaotic nonlinear system can be quasiperiodic and apparently causal for a while and then for no computable reason change to an entirely different mode of behavior where a significant quasiparticle/process becomes insignificant and some other process becomes the critical driver.

AlecM

The reason why arid deserts heat up rapidly during the day is because there is little water to evaporate. This means the rate of heat loss from evapo-transpiration, the major heat transfer process from the surface over most of the World, is low.
The surface temperature rises until the next most important heat transfer process, IR energy via the ‘Atmospheric Window’, a T^4 process, acts to limit surface temperature, up to c.50 deg C.
The GHE is from clouds; there are no clouds in deserts. The proof that heat transfer from deserts is mainly radiative in the AW is the fast cooling at night. The Bedouin make ice by digging pits in the desert, minimising convective heat transport to the surface. The moral of this story is that there is no GHE from ‘back radiation’.

Ben

Even with the poor grasp of internal chaotic variability, these models omit both the geological and cosmic chaos that are important factors in long term climate change perspective.

Tim Walker

A very worthwhile read. Thank you.

joelobryan

Thanks. Enjoyed the reading. So a single butterfly flapping its wings in South America is still the best explanation for the quite modest Northern Hemisphere warming these last 30 years.
I see global cooling (e.g. Dr Brown’s, “several tenths of a degree, sustained, not just vary up or down or weakly downward trend”) needing at least one full IPCC AR cycle, ~5 years sustained lower global temps, to bring about the AGW catastrophe (i.e. the demise of the AGW meme).

milodonharlani

mellyrn says:
May 21, 2014 at 11:41 am
Polar ice sheets aren’t going to melt right away, even if we cranked up the CO2 generators to higher levels & for much longer than humans have been burning fossil fuels.
Shaviv et al find cosmic explanations for the apparent roughly 150 million year cycle out of Hothouse & into Icehouse climatic conditions. Whatever might be the reality of their case, earth has been in an icehouse since the Oligocene, when Antarctica became separated from Australia & South America by deep oceanic currents (the uplift of the Himalayas beginning in the Eocene has also been cited by some workers as a contributory factor, but mainly by the CACA mafia). The cold worsened in the past three million years with the interruption of ocean currents caused by the formation of the Isthmus of Panama.
Cycles on the orders of 10,000 & 100,000 years of ice growth during glacials & interglacial retreat (as now) appear to be largely under orbital mechanical control.

Gary Pearse

Thank you Dr RG Brown. It is very refreshing every once in awhile to get the big picture in compelling prose. So much of climate science seems to be frustratingly a hodge podge of analyses of little things. The recent paper on melting West Antarctica glaciers adding 450 microns a year to sea level; the terrible fate of the gorse on almost barren Campbell Island (300 miles south of NZ), because of irregular warm and cold winters (I’m not sure what winter has been warm down there for some time – Antarctica has been cooling throughout the satellite era); a river mouth sandbar community in Alaska had to be moved because the bar (a highly insubstantial land form)was being eroded…. storm tracks are moving a few tens of metres poleward over the past decade…Ohio braces for CAGW algal growth in (shallow) Lake Erie… I guess these minutiae are a measure of what scale they generally feel comfortable dealing with.
My view of all this is that if the globe is heading for incineration, there should be mega-effects telegraphing this. Tiny corrections of fractions of a mm on a sea level they expect to rise a number of metres. A correction of 0.O1 here and an 0.02C there when we are to be anticipating 3 to 6C increases is actually a measure of the uncertainty that resides in their hearts. Of course it is also a way to keep up the narrative.
I feel that Dr. Brown is more than generous in his evenhanded assessment of the cooling or warming future that might ensue. I basically agree with this but not because I would feel obliged to accept the science of the CAGW proponents. Enso might heat it up, AMO might pause and then go up unexpectedly….. Possibly we could use up gas reserves by blasting flaming gas jets at the tropical sea surface….whatever, but the present global warming math has to be largely scrapped and redone. It shouldn’t be seen as rescued by ENSO. BTW, watch for ENSO to become the stored form of CO2 caused warming.
The IPCC itself was given scientific and policy guidelines at the outset by UNFCCC which was set up by the Maurice Strong, a rabid anti civilization, new world order zealot. No one has been searching for non-anthropogenic warming among the orthodoxy. When a malthusian policy wonk with no scientific credentials invents the science of CAGW as a tool for subjugation, we are being generously evenhanded indeed.

john robertson

Thank you, another great comment.
Please keep them coming, every time I read a Robert Brown posting I feel like I learnt something.

CRS, DrPH

Thank you, Dr. Brown! I feel as if I just sat through a very high-level physics lecture, and definitely learned quite a bit.
I’m not sure if the question is “Is climate computable?” as much as “Are the factors that may have an impact on climate computable?” The albedo of a large, fluffy white cloud can probably be computed rather precisely. However, the physics and chemistry of cloud formation are proving to be so incredibly complex that I doubt we will ever figure these out with great reliability in our lifetimes.
Factors that figure into cloud formation include cosmic rays (Svensmark), atmospheric concentrations of ammonia and sulfate, particulates, certain species of bacteria and even meteoroid dust (noctilucent clouds at least). I don’t think it is possible with present computing power, we haven’t even figured out the correct questions to ask.

albertalad

What is climate if not weather over time? And in any future yet not lived it is weather to those living in that future. Can we predict weather today? Not in my neck of the woods to any degree of certainty. And if we cannot predict the most fundamental of weather on a daily basis how can anyone predict climate? We cannot predict that now despite all the tools man uses.

paullinsay

The entire premise that the heating by CO2 was boosted due to positive feedback from water vapor has always been absurd in my mind. If that’s true for CO2 why isn’t it true for water vapor itself, in which case, the feedback should be saturated by the water vapor due to its infinite abundance? There would have to be something magic about the 15 um CO2 lines that isn’t true of any other IR radiation, even the overlapping water vapor lines at 15 um and up.

AlecM

@mellyrn: the Earth is cool at present because we have polar ice caps and thermohaline circulation. This takes Fe to the Equatorial regions thereby allowing phytoplankton to grow. These produce many cloud condensation nuclei and the clouds increase albedo, thereby reducing average surface temperature.
Ice ages are a cold phase caused by the reduction of CCN, increasing cloud albedo. However, because SSTs are low enough and there is still (slow) thermoohaline circulation,, there are still residual phytoplankton and some CCN. In times like the Devonian, there was no thermohaline circulation, equatorial seas were barren so despite high humidity, there were few, if any CCN or clouds.
What this means is that the Earth is tristable; ice ages and interglacials with thermohaline redistribution of Fe, and hot times with no polar ice so no thermohaline circuit.

David McKeever

This piece is a model of clarity and conciseness. Many thanks.

“Is climate computable?” Maybe, but not with current techniques.
It appears to me that the GCMs are going about it a very hard way. As I understand it, they’re trying to compute weather in sufficient detail and over a long enough period to extract climate.
That seems like a lot of work. It’s also fraught with hazard. For example, Navier-Stokes is known to “blow up”. To me, that speaks of a deeper problem – non-linearity. Once you’re into that domain (and weather is), you can’t accurately predict specific events very far out.
Once you try you try to calculate weather, it’s only a matter of time before your model goes off the rails.
It might be possible to get there with some kind of quasiparticle ensemble that only calculates their probability of existence and movement, without ever calculating any actual weather. It could contain output like “cell xxxxx has a 49% chance of cloud formation between 2pm and 4pm”, without ever actually evaluating whether or not a cloud forms.

mkelly

Dr. Brown says: “If we have a super El Nino that heats the planet by 0.3C very rapidly,…”
This would prove it is the sun and nothing to do with CO2.

David Riser

Very Nice Post!
v/r,
David Riser

Rud Istvan

Leftturnandre, because if the watervapour feedback were negative instead of weakly positive, we would not observe the climate we do. But a weak positive gives a very different TCR and ECS, more in line with Lewis and Crok (1.1 ‘grey body’ Stefan Boltzmann, 1.3 TCR, 1.7 ( thereabouts) ECS) compared to the canonical and never changed since Charney swag ECS 3.0. The difference is between “so what’s the fuss? and CAGW!!!

HAS

I have some familiarity with the use of multi-scale modelling to help model complex systems at the quantum, molecular, and nano and meso scales. I have wondered whether these techniques have been applied to modelling the thunderstorm to regional climate problem.

Dave Yaussy

I hope Dr. Brown keeps commenting. His thoughts are unusually cogent and understandable. on basic issues that I need help with. Even when he talks about matters I can’t understand, I can at least see the outlines of what I don’t know.

Personally, I won’t even place a bet. I don’t think the climate is computable, which means that I think one is basically betting on the output of a (possibly biased) random number generator.
The Catastropharians have placed their bets on the computer models, this much is certain.
When you have been embezzling the company accounts,
then a decision to play the lottery is rational.
If you win, you keep your freedom and your good name.
If you lose…. you haven’t lost much because you were going to jail anyway.

Michael 2

Eddi Rebel says: (May 21, 2014 at 11:33 am)
“Why is it hotter during the day without GHE? I thought GHE always warms?”
GHE *insulates* — whether it *warms* depends on the existence of a heat source and where it is.
In a REALLY hot desert, if you are going to be in the heat for only a short time, wear a parka! Doubtless you’ve seen heavily dressed Beduin. It slows down heat GAIN. So it is with atmosphere. Sunlight is broad-spectrum and includes visible and infrared portions in a ramp kind of energy vs wavelength graph.
In the desert, the lack of water vapor, the leading GHG, allows nearly the entire spectrum to reach the surface — whereas nearby in areas with more humidity, a substantial portion (about 40 percent I think) of the sunlight never reaches the surface — and that’s just GHG, not to mention clouds. CO2 exists in the desert and BLOCKS incoming solar radiation in a few segments of the spectrum.
Greenhouse gases can, therefore, have a “net cooling” (which actually means “less warming”) as compared to their absence in certain situations. Removing all GHG (and the atmosphere) would allow desert surface temperatures to become the same as the moon.
“The temperature on the Moon varies from -387 Fahrenheit (-233 Celsius), at night, to 253 Fahrenheit (123 Celsius) during the day. ” http://coolcosmos.ipac.caltech.edu/ask/168-What-is-the-temperature-on-the-Moon-

mellyrn

@ milodonharlani, AlecM —
Thank you kindly, but it was sort of rhetorical, to point out that, well, current climate ain’t normal; “much hotter” is normal, and will return regardless of human activity.
“Cosmic” explanations — there may well be a perceptible cycle, but why? What’s changing? Does the sun pass through regions of space that kick it into higher gear, or cause it to slow down?
The presence or absence of the thermohaline circulation and CCNs — chicken or egg? Does a warmer world slow down the THC?
There is so much we don’t know. rgbatduke’s analysis of the, well, chaos is most excellent.

hunter

Thank you very much, Dr. That was a very accessible summary of water’s various roles in the climate. It would be highly informative to know your views on the so-called CO2 climate control knob concept taht was promoted a few years ago.

Theo Goodwin

“That’s why I hesitated to assign a sign to the net feedback from any sort of local modulation of e.g. ocean-air humidity or sea ice coverage. The processes are COMPLEX and can have either sign, and they are NON-LOCAL as adding humidity in one place can increase albedo someplace else thousands of miles away is it finally concentrates enough to form clouds. A large part of the rain that falls over North Carolina comes up from the Gulf of Mexico maybe 1000 miles away. Some of it comes all the way over from the Pacific, where some of that might have originated in e.g. the growing El Nino. Heat from the tropical Pacific can be transported all the way to NC before it finally releases its heat and falls as rain, before it finally creates clouds that cause NC to cool after helping to greenhouse warm much of the surface area it crossed in between.
This is the kind of thing that the models are supposedly trying to model, but they perforce replace all of the small-length scale detail of this description with presumptive averages over cells 100-300 km square (where weather phenomena such as thunderstorms are order of 1 to 10 km square, where the details of front structure and development are much finer than this).”
What a brilliant essay. I tried to find a shorter quotation but you think in highly structured paragraphs. Your description of the very large challenges that face scientists who attempt to measure albedo or other effects of water vapor are quite persuasive. Your criticism of efforts to model such phenomena are devastating.
I take it that modelers are committed to a party line on these matters and that is the reason that we never see discussion of the challenges that you have described here. I take it that the same is true for scientists who are not modelers but who are attempting to measure the phenomena and to formulate scientific hypotheses about the behavior of water vapor as it affects warming.
I do not know that I have seen an article which addresses, even in part, the challenges that you have described. Yet I have known that those challenges were there. So, I have doubted both the modelers and the physical scientists for not being honest about the work that must be done before there is reasonable confidence in something like “climate sensitivity.”
Thank you for making clear what modelers and scientists must do if they want to get real and be taken seriously.

milodonharlani

mellyrn says:
May 21, 2014 at 12:58 pm
“Cosmic” explanations — there may well be a perceptible cycle, but why? What’s changing? Does the sun pass through regions of space that kick it into higher gear, or cause it to slow down?
———————–
Cosmoclimatology has progressed a lot from Shaviv’s early work, but here’s a reference:
http://arxiv.org/abs/astro-ph/0209252
Cosmic ray flux over time is suggested as an explanation for observed glaciations.

ossqss

Quite enlightening as to how the climate system can juggle energy.
Thanks Dr. Brown and Anthony for sharing.
I read an interesting release yesterday, that I cannot locate, on how ice loss can contribute to techtonic and volcanic activity. Anyone else see that?
Regards Ed

AlecM

@Michael 2: you re right about the extra SW in the dry desert. It’ll be a maximum of 49%. I expect about 30% more SW.

milodonharlani

ossqss says:
May 21, 2014 at 1:10 pm
The hypothesis that reduced ice load can lead to increased volcanism has often been discussed on this blog.
http://adsabs.harvard.edu/abs/2011AGUFM.U53E..03A

“The trouble is that water vapor is literally a two-edged sword.”
Literally?
“This last assumption is finally dying a quiet and well deserved death. AFAIK, it is due to Hansen”
Water vapour feedback was built into the original calculations of Arrhenius. But it isn’t something that is explicitly included in GCMs. The ocean boundary conditions include Clausius/Clapeyron relations; evaporation necessarily increases with warmth.
” Naturally, some of the GCMs out there have built into them parametric assumptions that preserve this much “climate sensitivity” — total ACO_2 warming plus feedback, usually at the expense of an overdriven response to e.g. volcanic aerosols necessary to explain periods of global cooling and to keep the model from having a runaway exponential instability”
I’d like to see more details of that. I’m not aware of it, and it’s not obvious how it could be done.
“the climate cannot be a biased random walk where every time the temperature goes up a bit, average water vapor increases and hence resets the Earth’s average temperature a bit higher”
Why not? That is the basic mechanism of wv feedback. You get, say, 1° warming which makes enough wv to create 1/2° warming, which then makes 1/4° warming – nett effect 2° warming. It decreases stability, but to get runaway you need wv from 1° warming to cause 1° extra warming. Then it runs.

Matthew R Marler

good post, but: The trouble is that water vapor is literally a two-edged sword.
Water vapor is not “literally” a sword.

milodonharlani

Nick Stokes says:
May 21, 2014 at 1:21 pm
Arrhenius also tried to include nebulosity in his calculations, but the worse than worthless GIGO GCMs upon which tens of billions in treasure have been squandered ignore clouds. Just one of the many sources of the models’ worse than worthlessness is ignoring water vapor effects other than the radiative, such as evaporative cooling, convection currents & reflection off & shading by clouds.
Runaway global warming is a preposterous fantasy. Earth’s climate system is homeostatic. Our atmosphere doesn’t resemble that of Venus, despite Hansen’s warrantless hysteria, which has cost the lives of tens of thousands (at least) & trillions in wasted “alternative” energy developments foisted upon humanity by the academic-industrial complex.

hunter

Nick, perhaps you can clarify your calcualtion of 1+ 0.5 + 0.25 = 2.0?

Tom Billings

mellryn asked:
“MY question is, what caused Earth to become abnormally cold, as it is now?”
Apparently, it is several changes since the time our PacNW Douglas Fir grew on the shores of the Arctic Ocean. That Ocean was open water during the early Eocene. The air currents across Eurasia were uninterrupted by mountains, and warmth moved easily. CO2 was high.
Then, about 50 million years ago, CO2 was sequestered to the bottom of the sea by an Eocene Arctic Ocean equivalent to Sargasso Weed, or other salt water Kudzu. It sucked up the CO2, and fell to the bottom as it died, trapping the carbon there. As well, the Himalayas began to rise, as India was colliding with the Eurasian Landmass. These mountains have been interrupting the flow of warm air into the North of Eurasia. This combination change to Eurasian climate influenced the the whole planet so that by 34 million years ago we had an icehouse climate. Its latest manifestation is in the 2 million years of the current Ice Age, while we live in the interglacial period known as the Holocene.

Hunter
OK, geometric progression
1+0.5+0.25+0.125+… = 1/(1-0.5) = 2

DrTorch

Excellent piece here.