Does CO2 Drive the Earth’s Climate System? Comments on the Latest NASA GISS Paper
by Dr. Roy Spencer
There was a very clever paper published in Science this past week by Lacis, Schmidt, Rind, and Ruedy that uses the GISS climate model (ModelE) in an attempt to prove that carbon dioxide is the main driver of the climate system.
This paper admits that its goal is to counter the oft-quoted claim that water vapor is the main greenhouse gas in our atmosphere. (They provide a 1991 Lindzen reference as an example of that claim).
Through a series of computations and arguments, the authors claim that is actually the CO2, not water vapor, that sustains the warmth of our climate system.
I suspect this paper will result in as many opinions in the skeptic community as there are skeptics giving opinions. But unless one is very careful in reading this paper and knows exactly what the authors are talking about, it is easy to get distracted by superfluous details and miss the main point.
For instance, their table comparing the atmospheres of the Earth, Venus, and Mars does nothing to refute the importance of water vapor to the Earth’s average temperature. While they show that the atmosphere of Mars is very thin, they fail to point out the Martian atmosphere actually has more CO2 than our atmosphere does.
I do not have a problem with the authors’ calculations or their climate model experiment per se. There is not much new here, and their model run produces about what I would expect. It is an interesting exercise that has value by itself.
It is instead their line of reasoning I object to — what they claim their model results mean in terms of causation– in their obvious attempt to relegate the role of water vapor in the atmosphere to that of a passive component that merely responds to the warming effect of CO2…the real driver (they claim) of the climate system.
OUR ASSUMPTIONS DETERMINE OUR CONCLUSIONS
From what I can tell reading the paper, their claim is that, since our primary greenhouse gas water vapor (and clouds, which constitute a portion of the greenhouse effect) respond quickly to temperature change, vapor and clouds should only be considered “feedbacks” upon temperature change — not “forcings” that cause the average surface temperature of the atmosphere to be what it is in the first place.
Though not obvious, this claim is central to the tenet of the paper, and is an example of the cause-versus-effect issue I repeatedly refer to in the past when discussing some of the most fundamental errors made in the scientific ‘consensus’ on climate change.
It is a subtle attempt to remove water vapor from the discussion of “control” over the climate system — by definition. Only those of us who know enough of the details of forcing-feedback theory within the context of climate change theory will likely realize this, through.
Just because water vapor responds quickly to temperature change does not mean that there are no long-term water vapor changes (or cloud changes) — not due to temperature — that cause climate change. Asserting so is a non sequitur, and just leads to circular reasoning.
I am not claiming the authors are being deceptive. I think I understand why so many scientists go down this path of reasoning. They view the climate system as a self-contained, self-controlled complex of physically intertwined processes that would forever remain unchanged until some “external” influence (forcing) enters the picture and alters the rules by which the climate system operates.
Of course, increasing CO2 is the currently fashionable forcing in this climatological worldview.
But I cannot overemphasize the central important of this paradigm (or construct) of climate change theory to the eventual conclusions the climate researcher will inevitably make.
If one assumes from the outset that the climate system can only vary through changes imposed external to the normal operation of the climate system, one then removes natural, internal climate cycles from the list of potential causes of global warming. And natural changes in water vapor (or more likely, clouds) are one potential source of internally-driven change. There are influences on cloud and water vapor other than temperature which in turn help to determine the average temperature state of the climate system.
After assuming clouds and water vapor are no more than feedbacks upon temperature, the Lacis et al. paper then uses a climate model experiment to ‘prove’ their paradigm that CO2 drives climate — by forcing the model with a CO2 change, resulting in a large temperature response!
Well, DUH. If they had forced the model with a water vapor change, it would have done the same thing. Or a cloud change. But they had already assumed water vapor and clouds cannot be climate drivers.
Specifically, they ran a climate model experiment in which they instantaneously removed all of the atmospheric greenhouse gases except water vapor, and they got rapid cooling “plunging the climate into an icebound Earth state”. The result after 7 years of model integration time is shown in the next image.
Such a result is not unexpected for the GISS model. But while this is indeed an interesting theoretical exercise, we must be very careful about what we deduce from it about the central question we are ultimately interested in: “How much will the climate system warm from humanity adding carbon dioxide to it?” We can’t lose sight of why we are discussing all of this in the first place.
As I have already pointed out, the authors have predetermined what they would find. They assert water vapor (as well as cloud cover) is a passive follower of a climate system driven by CO2. They run a model experiment that then “proves” what they already assumed at the outset.
But we also need to recognize that their experiment is misleading in other ways, too.
First, the instantaneous removal of 100% of the greenhouse gases in the atmosphere except for water vapor causes about 8 times the radiative forcing (over 30 Watts per sq. meter) as does a 100% increase in CO2 (2XCO2, causing less than 4 Watts per sq. meter), something that will not occur until late this century — if ever.
This is the so-called ‘logarithmic effect’…adding more and more CO2 has a progressively weaker radiative forcing response.
Currently, we are about 40% of the way to that doubling. Thus, their experiment involves 20 times (!) the radiative forcing we are now experiencing (theoretically, at least) from over a century of carbon dioxide emissions.
So are we to assume that this dramatic theoretical example should influence our views of the causes and future path of global warming, when their no-CO2 experiment involves ~20 times the radiative forcing of what has occurred to date from adding more CO2 to the atmosphere?
Furthermore, the cloud feedbacks in their climate model are positive, which further amplifies the model’s temperature response to forcing. As readers here are aware, our research suggests that cloud feedbacks in the real climate system might be so strongly negative that they could more than negate any positive water vapor feedback.
In fact, this is where the authors have made a logical stumble. Everyone agrees that the net effect of clouds is to cool the climate system on average. But the climate models suggest that the cloud feedback response to the addition of CO2 to our current climate system will be just the opposite, with cloud changes acting to amplify the warming.
What the authors didn’t realize is that when they decided to relegate the role of clouds in the average state of the climate system to one of “feedback”, their model’s positive cloud feedback actually contradicts the known negative “feedback” effect of clouds on the climate’s normal state.
Oops.
(In retrospect, I suppose they could claim that cloud feedbacks switched from negative at the low temperatures of an icebound Earth, to being positive at the higher temperatures of the real climate system. But that might mess up Jim Hansen’s claim of strongly positive feedbacks during the Ice Ages).
CONCLUSION
Taken together, the series of computations and claims made by Lacis et al. might lead the casual reader to think, “Wow, carbon dioxide really does have a strong effect on the Earth’s climate system!” And, in my view, it does. But the paper really tells us nothing new about (1) how much warming we can expect from adding more CO2 to the atmosphere, or (2) how much of recent warming was caused by CO2.
The paper implies that it presents new understanding, but all it does is get more explicit about the conceptual hoops one must jump through in order to claim that CO2 is the main driver of the climate system. From that standpoint alone, I find the paper quite revealing.
Unfortunately, what I present here is just a blog posting. It would take another peer-reviewed paper that follows an alternative path, to effectively counter the Lacis paper, and show that it merely concludes what it assumes at the outset. I am only outlining here what I see as the main issues.
Of course, the chance of editors at Science allowing such a response paper to get published is virtually zero. The editors at Science choose which scientists will be asked to provide peer review, and they already know who they can count on to reject a skeptic’s paper.
Many of us have already been there, done that.
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I am a simple experimental physicist with many years experience in computer modeling for elementary particle theories.
I cannot see how it is possible, if one takes out CO2 completely from the atmosphere, H2O will act completely like and anti – greenhouse gas.
When I look at the absorption spectra of H2O and the rest of the greenhouse gases, I see a great overlap of H2O, which is also much more abundant. Correct me if I am wrong, but specific humidity does not go below a part in a thousand, and how could it on a planet that is 75% water.
That measly 390ppm will be taken up by the long term reservoir of the non dry atmosphere and do the job CO2 et al were doing, if the program is programmed correctly.
Fluid mechanics does not know atoms and molecules at that level. If anthropogenic CO2 has a residence time of thousands of years according to the paper, then the baseline H2O has one of millions of years, it is there and will do its greenhouse job, imo. I suspect that in their feedback/forcing confusion( terminology that gives me hives as a physicist) they ignore that there is an underlying level of specific humidity, H2O vapor, that cannot be condensed/precipitated etc out of the atmosphere because of the basic physics of gases. That must be how they get their ice.
p.s. to my last
It happens that Modeling the Basics, A mathematical summary of condensation in climate models. a flaw in GCMs is being discussed over at Jeff Id’s AirVent. Seems all the GCMs have it wrong as far as condensation and pressure goes. Might be a related problem of how this specific GCM turns H2O from a greenhouse to an anti-greenhouse gas.
What more can one say about the paper? GIGO.
If removing all the greenhouse gases from the atmosphere causes a snowball earth then we can conclude we shouldn’t remove them. Not that the temperature would matter any. When CO2 drops to half the present value it’s not enough for plants to survive and without them animals can’t survive and the earth becomes a paradise for prokaryotic extremophiles and little else.
Recent research suggests that methane accounts for about half the GHG effect and since its residence time is very short compared to CO2 and it has little if any benefit to the vast majority of the biosphere we should, if we’re really concerned about GHG warming, be targeting anthropogenic methane (with a vengeance) instead of CO2. The risk vs. reward situation with methane is immensely more attractive and would yield results (one way or another) in a short enough span of time to give climate “science” some remote semblance of an experimental science rather than the current state of being a forensic science dominated by narrative accounts of possible futures rather than the testable predictions of experimental sciences.
@ur momisugly crosspatch says: October 21, 2010 at 10:38 pm :
I studied paleoclimatology in the Holocene at University and, like you, came to the conclusion that the biggest feedback mechanism operating during glaciations was the thickness of the ice and its effect on surface altitude.
I heard it mentioned once, in passing, during a lecture, with nary a word in any of the many books and papers I read on the subject…
Can you say “can’t see the wood for the trees?”
Come on Dr Roy; you are pulling our legs. Fess up now, you made this whole yarn up; didn’t you ?
What scientist worth his salt, who had ever been in a high altitude arid desert at night and frozen his; well you know what he froze; would claim that it was CO2 that keeps the planet warm ?
If my office wasn’t so small I’d be rolling on the floor laughing my A*** off .
So take every last molecule of H2O out of the atmosphere ( I believe that Peter Humbug actually did this over at r-c , on his Playstation) and what do you get; with NO water vapor; and NO CLOUDS and all the CO2 you can fit on your plate ?
Well you get the mother of all “forcings” with suddenly a very small planetary albedo; and you no longer get a Black Body Equilibrium Temperature that is sub zero (C) at the earth’s orbital location.
Well you soon get all your water and clouds back in a hurry; even with not a single extra CO2 molecule added. I believe Peter Humbug said he got it all back in three months.
Hey Roy; it is Halloween that is coming up; Not April Fool’s Day; ah what a good laugh to end the week !
George
“”” John S. says:
October 22, 2010 at 6:22 am
What the authors didn’t realize is that when they decided to relegate the role of clouds in the average state of the climate system to one of “feedback”, their model’s positive cloud feedback actually contradicts the known negative “feedback” effect of clouds on the climate’s normal state.
Dr. Spencer, doesn’t clouds’ role in feedback depend on the time of day? In the daytime, cloud cover is a negative feedback, allowing less solar energy to reach the surface. But at night cloud cover is a positive feedback, blocking re-radiation from the surface back into space. “””
Green house gases DONOT warm the surface; they DO warm the atmosphere; and they DO NOT block the exit to space of LWIR radiation; they DO delay that exit.
During the daylight hours the sun is pouring in solar energy to the SURFACE. That rate of energy input times the average delay of LWIR exit caused by GHG intervention is the extra heat load that results in an upwards offest in the Black Body like equilibrium surface Temperature. That is the source of the Temperature rise.
At night, it still cools down after sunset; because the sun is no longer pouring in solar energy, and the GHGs (and clouds) cannot stop the exodus of the LWIR radiation; merely delay it. And since the sun is not adding energy during the night; no energy offset occurs, and no Temperature offset either, due to that delay.
The clouds at night are CAUSED by the surface warmth during the day; they are not the cause of the surface warmth at night. It never warms up after sunset unless a totally different warm air mass moves in from somewhere else; it always cools; and with no water vapor in the air, as in high arid deserts; it cools damn fast; no matter how much CO2 there is.
I’m going to go to my grave still looking for a cloud that passed in front of the sun, and made the Temperature higher in the shadow zone.
Clouds ALWAYS reduce the total amount of solar energy that reaches the earth’s surface (mainly the ocean) and gets stored in the earth (deep oceans). There are NO exceptions to this rule, anywhere on earth, at any time, for any reason. What else clouds do is open to debate; but they DO NOT increase the amount of solar energy that reaches the surface of the planet. The total amount of solar energy that the earth receives and retains, is what determines its Temperature.
And I don’t care what happens on the Moon, or Venus, or Mars.
John S. says:
October 22, 2010 at 6:22 am
“Dr. Spencer, doesn’t clouds’ role in feedback depend on the time of day?”
To some extent, yes. Clouds drastically change albedo which is important only when the sun is high in the sky.
What is missing and has been mentioned over and over again on WUWT is the heat transport from surface to altitude that occurs when clouds form. Liquid water requires a tremendous amount of energy to become a vapor. The bulk of the energy it carries, called latent heat of vaporization, doesn’t register on a thermometer. That’s why it’s called latent. The temperature of the liquid or gas is called its sensible heat.
So when water evaporates on the ground it takes up a tremendous amount of sensible heat from the surface and carries it quickly high aloft through convection. As the adiabatic lapse rate does its magic the water vapor cools as it rises until it reaches the dewpoint and condenses into a cloud. When it condenses to a liquid it gives up all that latent heat it carried which becomes sensible heat in the surrounding atmosphere which causes even more convection so much that the tops of thunderstorms can penetrate the stratosphere.
When all this energy is removed from the surface and released at altitude it acts to drill right through the densest greenhouse gases so that when the energy is released again as sensible heat the dense layer of greenhouse gases below it now serve to block that energy from returning to the surface and makes the path of least resistance a whole lot easier going upward into space. The process goes on day and night although it is dominated by cloud formation during the hottest part of the day and the water returning to the surface in the late afternoon or evening. Thus it tends to also raise the albedo at just the right time to moderate insolation reaching the surface.
The water cycle is a wondrous dynamic thing that stabilizes the earth’s temperature in a regime suitable for the life that evolved in it and is poorly modeled mostly through arbitrarily defined constant values in global circulation models. There’s no evidence whatsoever that there is any positive warming feedback associated with the water cycle that would increase with temperature. The earth has NEVER experienced a runaway greenhouse even with CO2 levels in past 10-20 times greater than today. What the earth HAS experienced is ice ages. Water in its solid phase is hideously effective negative feedback that can and does produce catastrophic global cooling. There’s a tipping point alright but it isn’t a tipping point into a very warm earth it’s a tipping point into a frozen earth. If it cools enough so that ice formation exceeds ice melt for even a short period of time it’s a runaway effect as ice breeds even more ice. At that point CO2 may become the savior as plants don’t grow very well in ice so the major sink for atmospheric CO2 goes offline. In the meantime the ice doesn’t do a damn thing to stop volcanoes from belching it out so over a period of millions of year it might be the mysterious forcing that eventually melts the snowball earth. No one knows exactly what can rescue a frozen earth from the clutches of massive high albedo ice cover but it has been rescued from such a condition over and over through the geologic ages. We’re presently in an ice age in fact and teetering on the border between a comparitively warm interglacial period and two miles of ice covering everything north of Tennessee. Because of the negative feedback of snow and ice the transition from interglacial to glacial periods (the latter endures about ten times longer than the former) is a plunge that happens in a single human lifetime. Our civilization and most of the biosphere along with it will be well and truly screwed if we reach that tipping point. Any sane knowledgeable person greatly hopes that anthropogenic greenhouse gas emission is enough to keep that tipping point at a safe remove. Personally I don’t think there’s anywhere near enough economically recoverable fossil fuels to do more than marginally extend the length of the current interglacial period. Maybe, just maybe, it’ll be long enough to come up with some technological solution to how we are going to cope with the next ice age. In the meantime when it comes to fossil fuels, burn baby burn in the hope that it gives us enough time and economic growth to come up with a means of dealing with the end of the current interglacial period. The current interglacial has already lasted longer than average which is perhaps the sole reason that humans were able to build a global civilization – the extra two thousand years was just long enough so that modern humans who have survived a great many glacial epics didn’t get kicked back to a frozen stone age before they had a chance to radiate civilization across the planet and prosper enough so that technology had the means to bloom beyond fire, flints, spears, and cave drawing.
A well reasoned response, Dr Spencer. However, the scientific method has evolved beyond the mere discussion of logic and methodology. A scientific paper stands and falls on the ‘plagiarism principle.’ If any hint of plagiarism is found, the paper is rejected as unsound, otherwise it can be accepted as true provided it agrees with consensus.
Apologies for the long post but I wish to make 5 points.
First, Dr Spencer when commenting upon the latest NAS/GISS paper observes:
“They view the climate system as a self-contained, self-controlled complex of physically intertwined processes that would forever remain unchanged until some “external” influence (forcing) enters the picture and alters the rules by which the climate system operates”.
If that is their view, it shows a complete failure to understand and appreciate chaos theory. In a chaotic system, one does not need outside/external drivers to effect a change within the self contained system itself. The climate is a chaotic system (I understand that this is accepted on both sides of the debate), that being the case, it is strange that quakified scientists should hold the view expressed.
Second, the output of any model (assuming that it has been properly scribed/programmed) does no more than output the assumptions made by the programmer. It does nothing to prove whether those assumptions are valid. Given the assumptions made in the model, the result was a foregone conclusion and proves nothing.
Third, edmh says:
October 21, 2010 at 10:40 pm
“The FUTILITY of Man-made Climate Control by limiting CO2 emissions
A Layman’s view: Just running the numbers: watch
On average world temperature is ~+15 deg C. This is sustained by the atmospheric Greenhouse Effect ~33 deg C. Without the Greenhouse Effect the planet would be un-inhabitable at ~-18 deg C. The Biosphere and Mankind need the Greenhouse Effect.”
It is often claimed by AGW supporters that greenhouse gas component in the atmosphere is responsible for the apparent 33 deg C warming. But is this really so? I have a number of doubts about this assertion. First, I am sceptical that the assumed black body radiation said to emanate from the Earth is correct given that the 70% of the Earth is covered by deep oceans that store vast quantities of heat which they re-radiate and this fact alone renders the Earth a very different beast when compared to the Moon (or for that matter Mars or Venus). Second, some element of the assumed 33 deg C is accounted for not by the greenhouse effect of the so called greenhouse gases, but rather by the pressure and density of the atmosphere itself irrespective of the gaseous mix of the atmosphere. One significant reason that Venus is so warm, is due to the high pressure and density of its atmosphere. One significant reason that Mars is so cold, is due to the lack of pressure and density of its atmosphere. What if the pressure and density of the atmosphere (irrespective of its chemical composition, ie., whether or not it has any greenhouse gas component) accounts for a significant part of the 33 deg C component? For example, what if the pressure and density of the atmosphere (irrespective of its chemical composition) accounts for say 30 deg C of the apparent warming? This figure is used merely for the sake of argument, but this would mean that the greenhouses gases in the atmosphere account for only 3 deg C of the warmth (ie., 33 – 30 deg C). This has significant implications since (in the absence of our making the atmosphere denser by the sheer quantity/volume of manmade gas emissions) it means that changes in the greenhouse gases only acts on the 3 deg C element not on the entire 33 deg C element.
One has to bear in mind the relationship between temperature and height. Leaving aside stratification of the atmosphere and inversion, as a general rule of thumb in the troposphere there is a drop in temperature of 6.5 deg K per km. In other words, if I move from the valley and climb a 500 m hill, I will experience a 3.25 deg C drop in temperature. This is not because less energy from the sun is reaching the ground where I stand (in fact very slightly more energy is reaching me since I am that much closer to the sun and more importantly, the sun light has passed less distance through the atmosphere itself which atmosphere is partly opaque to sun light – albeit the amount of additional energy is immeasurably small). It is not because there is less CO2 (or greenhouse gas) blanket to keep me warm (to trap/delay the heat being radiated). It is because the pressure of air within the column of air directly underneath which I stand is less and there are very slightly less air molecules around me so even though these molecules may have slightly more energy there are less collisions transferring that energy). Unless this is properly taken into account, the entire context in which the apparent 33 deg C apparent warming occurs is misunderstood and the case for the impact of greenhouse gases over-stated.
Fourth, and this follows on from the third point. What precisely are we measuring when we seek to assess the average global temperature. Whilst this is in some way gridded to location, to what extent is it adjusted to take account of height at which the temperature is being measured. Obviously, for the purposes of calculating trend anomalies, the height is not relevant (unless there are station changes). However, it is relevant when saying that the global average temperature is ~ 15 deg C which we then use to extrapolate the ~ 33 deg C figure for the warming effect of the so called green house gases.
I have always been at a loss to understand how you can accurately calculate the average global mean temperature still less to understand its relevance. Without an infinite number of weather stations (both on land and in the sea) any assessment is bound to be horribly inaccurate. And what is the point, since there is one thing certain about averages, namely that most places do not experience the average temperature and in any event climate change is regional not global. In fact, in some places it will inevitably be very localised. The effect of climate change on the UK, Ireland, various regions within the States, Canada, Europe, Africa, India etc will all be different. There will be winners and losers. Policy makers need, for the main part, only to know how change will affect their country.
Fifth, it seems difficult to understand why a scientist (as opposed to a politician) would home in on CO2. There seems to be no significant and good correlation between CO2 levels and temperature change when viewed on either a geological scale or on a modern instrument scale. On the geological scale, there have been times when there have been modest levels of CO2 and yet it has been warm and where there have been high levels and yet it has been cold. Temperatures have fallen when CO2 levels have been rising and temperatures have increased whilst CO2 levels have fallen. As regards, the modern instrument period, temperatures rose significantly between 1850s and 1940 when there was little significant rise in CO2 levels. As soon as there were significant increases in manmade CO2 emissions, between 1940s and 1970s temperatures dropped! Of course, there is a short period when CO2 levels between 1970s and 2000 rose and so too did the temperature. However, between 2000 and 2010, temperatures have flat lined notwithstanding the rise in CO2 levels. Where is the correlation in all of this?
As I see the theory, since it is based upon the premise that any increase in CO2 must result in an increase in temperature (the theory does not allow temperatures to remain static or fall when CO2 levels increase), those that promote the theory need to explain for each and every year where there has been an increase in CO2 but not a corresponding increase in temperature why that is so. They need to explain what factors/mechanism over-shadowed the theoretical increase in temperature that must follow from the increase in CO2 level. If those promoting the theory cannot identify or otherwise explain the factors/mechanisms at work and how these counteracted the theoretical calculated rise in temperature but are left with a vague assertion that unexplained natural variations some how swamped the increase, then they are unable to rule out the possibility that the very same unexplained natural variations (and not CO2) led to the observed rise in temperatures between 1970s to 2000. In fact, no one can say that those unexplained natural variations are not responsible for the entire temperature changes between the 1850s to date.
Why is it so hard for us to admit the truth, namely (1) we lack the required accurate data from which to make meaningful extrapolations as to what is going on, (2) that we know little about the workings of the atmosphere and climate, and (3) we understand even less.
Lets come back in 20 or 30 years time when we may know and understand more.
“”” michael hammer says:
October 22, 2010 at 12:13 am
Hmmm, a simple calculation. The sun delivers 340 watts/sqM at the top of the atmosphere. Of this about 100 watts/sqM is reflected back out to space mainly by clouds. Now if there were no green house gases at all (including water vapour) there would also be no clouds. At 340 watts/sqM of insolation according to Stefans law the average temperature would be 5C or about 9C colder than it is now. “””
Well your numbers are a bit off. The current value for the TSI is about 1366 W/m^2 ; not 340.
And if you remove the clouds and the atmospheric water vapor, you get no cloud albedo reflection, and you get no water vapor absorption of perhaps 20% of the solar energy; so the atmosphere will likely cool; but the surface is going to get hotter as a result of that increase in solar energy at the surface.
I don’t know why climatists insist on dividing the TSI by 4, as if the weather and climate responds to the average energy impinging on the surface.
Try to get a desert surface Temperature of +60 to + 90 degrees C, with 340 W/m^2 impinging on it continuously, 24/7 .
Good luck on that.
Mother Gaia has a thermometer in each and every atom or molecule, so she can monitor the Temperature of every one of them at any moment; and she does not do averages. She does real time actual data, and she doesn’t use any computer programs to hide the decline.
“”” richard verney says:
October 22, 2010 at 9:09 am
Apologies for the long post but I wish to make 5 points. “””
Richard; the tires on my bike in my garage contain air including GHGs at a pressure of 65 PSI; which is 4.4 times the pressure of the outside atmosphere in my garage; and I can assure you that my tires are at exactly the same temperature as the air in my garage; as is the higher density and pressure air inside them.
Tom in Florida
October 22, 2010 at 5:39 am
Hey, have some respect for the desert inhabitants. Last thing we need is to see a bunch’o pasty-puffy-psudoescientsts running around buck nekkid, YIKES!
“””” John F. Hultquist says:
October 21, 2010 at 10:11 pm
. . . a 100% increase in CO2 (2XCO2, causing less than 4 Watts per sq. meter), something that will not occur until late this century — if ever.
If ever? I hope soon to see a post explaining whether or not that “goal” is attainable. How fast can human activities inject CO2 into the atmosphere? The faster we try (demand for coal and oil) the more costly they will become. Higher prices reduce demand and encourage alternatives. Can coal and oil be supplied fast enough and consumed fast enough?
How long does CO2 stay in the atmosphere? Is it 5, 10, or 200 years? Unless this is known how can one proceed? “”””
John,
CO2 has been in the atmosphere for at least the last 600 million years; and who knows how long before that.
So claims that it only stays in the atmosphere for 5, 10 or 200 years are just plain silly. For all practical purposes it is there permanently; and as it so happens; on planet earth H2O is also in the atmosphere permanently and always at greater levels than CO2 is.
So what does that have to do with climate ?
I have some really stupid questions. Water has a much higher specific heat then most of the other atmospheric gasses. Does the evaporation condensation cycle transport heat from the surface to the upper atmosphere? And does humidity have a significant effect on the total specific heat?
I’ve read statements on their sites saying that only weather is chaotic; climate is not.
(SarcOn) I’m tellin’ ya’ there’s just no way to handle all this extra Carbon Die Oxide stuff except by gettin’ a few billion nice people on this here planet to start holdin’ their breath permanently. Nope! Jus’ ain’t no other way!(SarcOff)
One and one is two! Always! Every time!
One little stupid thing plus another little stupid thing makes two little stupid things. Etc., Etc., Etc.!
We really do need to get our heads out of the simulated clouds and our feet back on solid ground before someone starts doing something really stupid and we’re talking about real money and a lot of heartache. Every time “science” and “technology” get out there too far ahead of the rest of us, or dreans up some bad, bad science fiction, a lot of people get hurt arguing about how, where, when, who, what, why, and which way we’re going to go. Simple minded people like Gore, Mann, Jones, and the lot, tend to like to keep things frightening and all glumped together so they’re able to get what they and their patrons want to achieve — a riot, or a war, or a revolution, all for the “good” of mankind and ‘their’ own bank accounts. Woo is me! What to do?
Why is it that when I read papers like Schmidt’s that I keep getting visions of Greek scientists explaining the beauty and complexity of epicycles? The equations related to planetary motion as explained by epicycles was even rendered into one of the most sophisticated mechanical apparati of the ancient word (the Antikythera mechanism) was nothing more than a mechanical computer model. That model, though it explained the motions of the planet with a measure of precision, still got the underlying science completely wrong.
http://en.wikipedia.org/wiki/Antikythera_mechanism
Stellar example of failing w.r.t. Simpson’s Paradox — will likely be a major textbook example in the future. [Good work Dr. Spencer.]
Also, missing the “+c” in the integral of f'(x) — classic.
Finally, Stephen Wilde, if you are around, what is this discovery you have recently been attributing to Joanna Haigh? I’ve been so busy I haven’t had time to read (in detail) every comment, but based in part on the above article & discussion, I’m getting the sense that multi-temporal-scale lapse-rate-variations (and related temperature differentials, cloud dynamics, & flows) deserve a serious look. Even if Haigh is wrong, a look at her ideas might stimulate some better ones…
Just because water vapor responds quickly to temperature change does not mean that there are no long-term water vapor changes (or cloud changes) — not due to temperature — that cause climate change.
What might those ‘longer-term’ changes be?
Dave Springer
October 22, 2010 at 9:02 am
Thanks for answering one of my questions before I posted it.
I posted this elsewhere on models, but it works here also
If you can not do clouds right, you have nothing
…..as an albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, which is the same amount a doubling of CO2 will give without the unproven feedbacks.
And…”… the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain
from the IPCC
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch1s1-5-2.html
“… the amplitude and even the sign of cloud feedbacks was noted in the TAR as highly uncertain, and this uncertainty was cited as one of the key factors explaining the spread in model simulations of future climate for a given emission scenario. This cannot be regarded as a surprise: that the sensitivity of the Earth’s climate to changing atmospheric greenhouse gas concentrations must depend strongly on cloud feedbacks can be illustrated on the simplest theoretical grounds, using data that have been available for a long time. Satellite measurements have indeed provided meaningful estimates of Earth’s radiation budget since the early 1970s (Vonder Haar and Suomi, 1971). Clouds, which cover about 60% of the Earth’s surface, are responsible for up to two-thirds of the planetary albedo, which is about 30%. An albedo decrease of only 1%, bringing the Earth’s albedo from 30% to 29%, would cause an increase in the black-body radiative equilibrium temperature of about 1°C, a highly significant value, roughly equivalent to the direct radiative effect of a doubling of the atmospheric CO2 concentration. Simultaneously, clouds make an important contribution to the planetary greenhouse effect. …”
I am not sure that there is any call for a resoponse to be made on what George says, however, I will briefly reply.
George E. Smith says:
October 22, 2010 at 9:22 am
“”” richard verney says:
October 22, 2010 at 9:09 am
Apologies for the long post but I wish to make 5 points. “””
“Richard; the tires on my bike in my garage contain air including GHGs at a pressure of 65 PSI; which is 4.4 times the pressure of the outside atmosphere in my garage; and I can assure you that my tires are at exactly the same temperature as the air in my garage; as is the higher density and pressure air inside them”.
George, do you know that? Have you got a thermocouple inside your tires measuring the temperature? You cannot measure the temperature of the air egressing from the tires when deflating them since this air is expanding and as you know expansion results in a reduction of temperature.
You are describing something quite different, namely that with time, and in the absense of some further inputs, the temperature of an object assimulates the temperature of its surroundings. An equalibrium is eventually achieved.
But if you are serious in your point, you might wish to consider the Gas Laws and put forward your proof disproving Boyle’s Law, Charles’s Law and the Ideal Gas Law. If you can do this, there is probably a Nobel Prize in it for you.
This is probably the most appropriate thread to mention this data, that I have discovered in the Infra-Red Handbook; chapter 3 on Natural Light Sources; and more specifically, 3.6 Radiation of the Sky as Seen from Earth. and 3.6.1 Sky Spectral Radiance.
And note that is Radiance and not Irradiance; so the units are microWatts per square cm, per steradian, per micron (of spectral wavelength.
In the text, they mention that the Infra-red sky background consists of scattering of the sun’s radiation, and by emission from atmospheric constituents.
So the solar scattering is a daylight phenomenon which they restrict to less than 3.0 microns; while the thermal emission is beyond 4.0 microns. They say the thermal radiation is represented by a 300 K black body radiation. They have a set of BB curves for Temperatures from 0 deg C to +40 deg C, and the spectral peak varies slightly around 10 microns; but the spectral radiance goes from about 600 at zero deg C, to about 1200 at 40 deg C, eyeballing the graphs, and in the above units. They add that this simple model is modified by a number of absorption bands, at 0.94, 1.1, 1.4, 1.9, and 2.7 microns for H2O in the solar spectrum plus CO2 at 2.7 microns.
For the thermal region; they say that spectral regions with strong absorption and emission bands, willa proach the black body curves for the appropriate Temperature OF THE ATMOSPHERE, and they mention the CO2 band at 15 microns, H2O at 6.3 microns, and O3 at 9.6 microns.
They plotted some rather strange looking curves; which are ACTUAL MEASUREMENTS taken at Elk Park Station in Colorado; which is a high altitude dry location, and for Cocoa Beach Florida, which is a more humid location.
These curves are measured for several Altitude angles from the horizon, so zero degrees is a horizontal reading measured through several air masses of the densest highest CO2 and H2O part of the Atmosphere; while 90 degrees is straight at the Zenith, through air mass one.
So here’s the weird result:- at zero degrees, the spectrum closely matches the BB spectrum peakign at about 10 microns and about 650 Radiance units (above), so it corresponds roughly to a 10 deg C Black Body spectrum in the Colorado case.
Same thing and spectral shape for Florida but about 900 units radiance corresponding to about +20 deg C.
So now what about other angles. Well in the zenith direction (90 deg AM-1), you get a very similar enveloped Spectrum; BUT with big holes in it. So the Black Body spectral limit is maintained; but now there are some spectral holes. In Colorado, which is dry, there’s a peak of about 450 units, at around 7 microns (H2O) and a small narrow peak about 150 at 9.5 microns (O3), then a dip to about 75 at 11 microns, and a CO2 peak about 575 at 15 microns, and a small unnamed peak about 200 at 18.5 microns. The sides of these dips are quite sloped so the peaks are sort of triangular.
In Florida where it is much higher humidity, the water peak at 7 microns is about 750 and the long wave edge falls very steeply to about 175 at about 8.5 microns, then pops up to the Ozone peak about 200 at 9.5 microns, the same 11 micron trough at about 175, than a slo rise to about 650 at14 microns, and then follows the BB envelope all the way.
For intermediate altitude angles you get intermediate results.
Now remeber these are observed spectra, and they are measuring spectral radiance, and not spectral irradiance (W/m^2).
So it’s a little puzzling; and I have to confess, I haven’t figured out yet exactly what I am looking at.
But clearly, the Temperature determined Black Body spectrum, does provide an envelope limit to the atmospheric LWIR radiation. But why does the horizontal umpteen air masses view give a rather mundane BB spectrum, with almost no spectral structure; although a tiny O3 pip can be ssen over Colorado at Zero degrees. Not sure where Elk Park is; but presumably it is at some elevated altitude; so it would be lacking the lowere denser atmosphere, and closer to the Ozone layer; which would get accentuated by the lack of the lower dense air. The Florida horizontal shows not band structure at all, neither O3, nor H2O, even though there’s a lot of H2O in a typical Florida beach atmosphere; and not a hint of CO2.
So I’m not quite sure what is happening; but it does suggest that those spectral regions which we know are capturing LWIR radiation such as 6.3, 9.6, and 15 for H2O, O3, and CO2 respectively ARE radiating at those same wavelengths and not so much from the N2, O2, Ar in the straight shot at the zenith; but horizontally it appears that the thermalization is complete; and the spectrum is simply Black Body Temperature dependent.
And I suppose what surprises me, is that the spectral spontaneous re-emission due to lack of thermalization, must be kicking in at a low enough altitude in the atmosphere, for those emissions to be quite significant in the straight down atmospheric thermal radiation.
So it generally is in agreement with my stick in the sand seat of the pants conjecture about what happens; with maybe the high altitude sources band spectral emissions being a bit spicier, than I would have guessed.
Maybe if Phil is out there he can kick in on this; because he seems to have a good handle on that aspect. I wish one could cut and paste pictures in here then you could all see what I’m seeing.
But nyet on the thesis that gases do NOT emit Black Body like thermal continuum LWIR electromagnetic radiation; but resonance band absorption spectra do show up as well in the overall ALL sky picture.
Now the IR Handbook is for the military to see and track and target things to blow them up; which is why they look horizontally through lots of air masses; and they do not care about climate scientists; or what they want to know; which is why they don’t have a dumb graph like an all sky surface Spectral Irradiance graph, instead of this silly Spectral Radiance thing; but my mind is somewhat adept at integrating in my head; sicne I’ve been doing it for 50 years or so.
And for you Academic Institutional types that have access to real libraries; you can check out the originals of these info bits in the following peer reviewed paper:-
E.E.Bell, I.L.Eisner, and R.A.Oetjen, “The Spectral Distribution of the Infrared Radiation from the Sky and Terrain at Wavelengths between 1 and 20 Microns. II. Sky Measurements, ” Journal of The Optical Society of America, Vol 50 December 1960, pp 1313-1320. There’s another paper referenced by the same authors on the same subject, in Proc of the Symposium on Infrared Backgrounds ERI; U of Michigan; which is sort of the origin of The Infrared Handbook. This along with my two volumes of “The Constitution of Binary Alloys” are my most treasured possessions after my fly rods, and reels.
I;m still a bit flabbergasted, that the stratospheric layer of long mean free path atmosphere; which allows spontaneous decay from excited states; shows up so prominently from the ground. Phil probably knows why.
Dave Springer :
October 22, 2010 at 9:02 am ,
I agree the imminent plunge to the next ice age is the only true prophecy . Resources should be concentrated to finding means of stopping it, rather than chasing the chimera of CO2 dubious anthropogenic contribution to heating.
The technological means exist, and the cleanest solution would be to orient mirrors in space and increase insolation judiciously. This means that the GCMs instead of chasing CO2 fantoms should be used to study insolation effects and cloud motions so that an intelligent decision can be made of where to focus extra energies from the sun.