Guest post by David Archibald
The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere, so instead of the average surface temperature being -15° C, it is 15° C. Carbon dioxide contributes 10% of the effect so that is 3° C. The pre-industrial level of carbon dioxide in the atmosphere was 280 ppm. So roughly, if the heating effect was a linear relationship, each 100 ppm contributes 1° C. With the atmospheric concentration rising by 2 ppm annually, it would go up by 100 ppm every 50 years and we would all fry as per the IPCC predictions.
But the relationship isn’t linear, it is logarithmic. In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic heating effect of carbon dioxide relative to atmospheric concentration:
And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
I recast Willis’ first graph as a bar chart to make the concept easier to understand to the layman:
Lo and behold, the first 20 ppm accounts for over half of the heating effect to the pre-industrial level of 280 ppm, by which time carbon dioxide is tuckered out as a greenhouse gas. One thing to bear in mind is that the atmospheric concentration of CO2 got down to 180 ppm during the glacial periods of the ice age the Earth is currently in (the Holocene is an interglacial in the ice age that started three million years ago).
Plant growth shuts down at 150 ppm, so the Earth was within 30 ppm of disaster. Terrestrial life came close to being wiped out by a lack of CO2 in the atmosphere. If plants were doing climate science instead of us humans, they would have a different opinion about what is a dangerous carbon dioxide level.
Some of the IPCC climate models predict that temperature will rise up to 6° C as a consequence of the doubling of the pre-industrial level of 280 ppm. So let’s add that to the graph above and see what it looks like:
The IPCC models water vapour-driven positive feedback as starting from the pre-industrial level. Somehow the carbon dioxide below the pre-industrial level does not cause this water vapour-driven positive feedback. If their water vapour feedback is a linear relationship with carbon dioxide, then we should have seen over 2° C of warming by now. We are told that the Earth warmed by 0.7° C over the 20th Century. Where I live – Perth, Western Australia – missed out on a lot of that warming.
Nothing happened up to the Great Pacific Climate Shift of 1976, which gave us a 0.4° warming, and it has been flat for the last four decades.
Let’s see what the IPCC model warming looks like when it is plotted as a cumulative bar graph:
The natural heating effect of carbon dioxide is the blue bars and the IPCC projected anthropogenic effect is the red bars. Each 20 ppm increment above 280 ppm provides about 0.03° C of naturally occurring warming and 0.43° C of anthropogenic warming. That is a multiplier effect of over thirteen times. This is the leap of faith required to believe in global warming.
The whole AGW belief system is based upon positive water vapour feedback starting from the pre-industrial level of 280 ppm and not before. To paraphrase George Orwell, anthropogenic carbon dioxide molecules are more equal than the naturally occurring ones. Much, much more equal.
Sponsored IT training links:
Worried about 642-426 exam results? Join 642-446 training program and get complete set of 350-029 dumps with 100% success guarantee.
Monckton:
This seems a perfectly clear exposition of what’s wrong with AGW theory.
So what in the above it beyond the capabilities of main-stream journalists? If I was a Harabin or Black, I would want to know from the Met Office experts exactly where the errors are in this, because clearly there MUST be some serious mistake, as we know from the Met Office just last week that AGW is real, and MUST be due to man-made interference with nature.
So seriously, if any main-stream journalists get to read this, why are you not doing your jobs and investigating? Surely it is the low-level arguments such as this that need to disproved by the AGW supporters who constantly tell us that the science has been clear for 150 years.
If they cannot disprove this, why do the MSM listen to them?
I don’t know if this post was supposed to be misleading and confusing but is certainly is.
Forcing is logarithmic! Surprisingly, climate scientists were aware of that.
The final graph is complete junk. Comparing forcing due to CO2 alone with forcing due to CO2 + feedbacks and finding that the latter is larger is pretty trivial.
Excellent post for the layman. But it would be nice to have a few citations. What is the source of the claim that “the first 20 ppm accounts for over half of the heating effect ?”
But the following is the true statement that is gives some perspective (and puts a smile on my face): If plants were doing climate science instead of us humans, they would have a different opinion about what is a dangerous carbon dioxide level.
The IPCC projection looks decidedly odd even for a layman. Unbelievable in fact. Since the amount of warming is also in doubt due to poorly sited and deleted thermometers I’m beginning to wonder what the AGW hypothesis has left to support it. Manic rants from those about to lose their cash cow appears to be the last resort. Even chairman Rudd has gone quiet and Penny Wrong has gone off to buy some floodwater.
“To paraphrase George Orwell, anthropogenic carbon dioxide molecules are more equal than the naturally occurring ones. Much, much more equal.”
————–
Borrowing another idea from Orwell’s “Animal Farm”:
– Four legged CO2 is a friend.
– Two legged CO2 is an enemy.
They have a nice theory, they have models that use the theory but these models future predictions all end up being wrong so end of theory in my mind.
The temperature sensitivity of CO2 is clearly not logarithmic over the entire range. The logarithmic relationship appears to range from about 40ppm to about 200ppm. After that it looks more like a 1/x type relationship. Maybe the whole curve is closer to 1/x. Has anyone tried doing such a plot?
I’ve read Davids papers on this before (I’m a layman I hasten to say). Apart from a derivative graph on the Junk Science site and a quote from Fred Hoyle I’ve not been able to dig out any further papers that support this idea. I’m told the science is settled, but something as basic as this seems to cut right to the heart of the whole argument…how could something as simple as this have been overlooked?
forcing due to CO2 + feedbacks
You mean like the melting ice-caps decreasing albedo. How’s that particular forcing working out for you?
The idea that water vapour suddenly kicks in at a particular CO2 concentration is extremely odd. Water vapour levels doesn’t depend on CO2 levels, just temperature and wind. We already have parts of the world which remain at high temperatures year round — the tropics. They would already be exhibiting the vapour feedback, and have done so for centuries. We have parts of the world which are always cold — the poles. No substantial mechanism effect there because they don’t get hot enough. So any water vapour effects will have to come at the margins, and they won’t generate the accelerating effect you need.
The idea that water vapour will cause accelerated warming seems to rest on the idea that the earth is a consistent temperature. Since it isn’t, there can be no magic kick-in point.
So what forcing are you actually relying on?
Nice one David,
I can’t stand it when an alarmist states (unchallenged) that the sceptics have not come up with one argument to upset the settled science. Well how about we get this into the head of the next talking head (to challenge) – hey dude CO2’s contribution is logartithmic not linear – heck that scientific enuff for ya. Plimer touches on it in his book – but well explained here, good job. I like the line about the point of view of the plants. You know, I reckon corals and foraminifera might like it for their skeletons too.
Excellent!
Mr Archibald:
May I translate this article into Spanish and publish it in my blog, with due recognition and links to the original, of course?
David Archibald’s conclusions are either true or not. Or am I being simple-minded? If he’s wrong why don’t climate scientists stop holding their noses and say why. Wouldn’t that be science?
This we’re-not-talking-to-each-other mentality is what is so frustrating to non-scientists like me.
I’d like Richard Telford to comment in greater detail. Then I’d like to see David Archibald respond.
And yes, I know we’ve all got day jobs … but hang on! Aren’t we sceptics all funded by Big Oil?
Richard Telford (01:00:29) :
May I respectfully suggest that you re-read the penultimate para. of the post, think, engage brain, think again, then make a considered response.
I’ve read in literature somewhere that CO2 contributes to about 25% of the greenhouse effect, i.e. 7-8°C. Can you cite where the 10% value comes from?
And there are other logarithmic curves, e.g. Lindzen, that are less flat after the first 300 ppm than the ones presented above. I’m wondering which are correct. Has Willis’s graphs been peer-reviewed? (Not that it makes a difference).
Its a curious thing that this point – well made by David here, still gets re-iterated and as far as I am aware, without response from the modellers. In the middle of last year I wrote a book aimed at my fellow environmentalists where I outline this issue – especially the 300% ‘gain factor’ in the equations – which is not so easy to derive from IPCC documents and for which I must thank Christopher Monckton in his article for the American Physical Society, where he tracks it down to James Hansen way back at the very beginning. It is a theoretical feedback, as Richard Lindzen pointed out at IPCC-1 in 1990! The modellers have taken the ‘warming’ (partly it now appears to have conjured and manipulated in the ‘gridded data set’ process) as evidence of the theoretical projection – and small wonder that when, after 2002, the warming ceased (no appreciable rise in upper oceanic heat content which is where 80% of the ‘warmth’ is held) that Kevin Trenberth at NCAR states in exasperation that it is a ‘travesty’ that they can’t account for the ‘lack of warming’.
You would think that at least one environmentalist from the long list of IPCC supporters would have either written to me, or pointed out in numerous public talks and discussions, where the refutation can be found – or that the MetOffice would have issues some guidance. Not one word!
So – given that this blogsite is visited by the orthodox – he is a challenge – please explain in simple terms, what is wrong with David Archibald’s presentation. I, for one, am open to listening and being re-educated – I care about the future of humanity, biodiversity…..the planet, but right now much of what I and others greatly value is threatened not by the projected consequences of carbon dioxide, but by the supposed remedy for climate change which will seriously and immediately damage landscape, biodiversity and community throughout the world, not to mention draining the pockets of taxpayers in a feeding frenzy of ‘jobs-for-the boys’ (Friends of Rajendra Pachauri rather than Friends of the Earth) – the technologies of turbines, barrages and biofuels.
So lets have an intelligent dialogue around this central issue – please!
Richard Telford (01:00:29) :
“I don’t know if this post was supposed to be misleading and confusing but is certainly is. Forcing is logarithmic! Surprisingly, climate scientists were aware of that.
The final graph is complete junk. Comparing forcing due to CO2 alone with forcing due to CO2 + feedbacks and finding that the latter is larger is pretty trivial.”
Looks like you have an excellent opportunity to demolish the sceptics with at most one follow-up submission which I hope you’ll make. Please avoid abuse such as ‘complete junk’ (makes you feel better but does not enlighten us) and tell us exactly where the author has gone wrong and mislead us
Richard Telford
Why is the last paragraph complete junk? Forcing is logarithmic. Surprisingly, climate scientists were aware of that….. were they? So why do you get such alarming amounts of warming out of a trace gas?
Either you know a lot that needs to be explained to the rest of us, or you don’t now nuffin.
Richard Telford (01:00:29) :
I don’t know if this post was supposed to be misleading and confusing but is certainly is.
Forcing is logarithmic! Surprisingly, climate scientists were aware of that.
Then why do their models produce an algebraic result?
Reply: Do you mean arithmetic? ~ ctm
If these graphs display the reality then why does the IPCC and the MET office want – seriously want – to continue propating the myth of AGW what is the purpose? If someone could describe to me in simple detail the reason behind the corruption of data and evidence that at the end becomes simple propaganda then whilst not being happy with the current situation I could at least understand why it exists.
You see it is a really big issue because if the BBC is correct according to their documentary serious about the solar system (last night) we only have 5 billion years left to sort the problem out.
Within that time frame the sun will implode and turn planet Earth into Walkers crisps hopefully if Al Gore is still around then he will get fried first so I am not going down to the gym and then restrict my diet to the minimum amount of calories so I live long enough to watch the episode on reality TV, I cant wait!
David Wells
I’m a little confused on this. The logarithmic nature of the Beer-Lambert law is well established but my understanding is that it applies even with an abundance of IR radiation that CO2 can absorb and dissipate as kinetic energy. Now, I’m under the impression that there exists a scarcity of IR radiation in the wavelengths which CO2 absorbs and the only effect of increasing the amount of CO2 in the atmosphere is that this finite amount of available energy gets absorbed closer to the ground.
So, is it correct that there are, in fact, two influences here, i.e. (a) the logarithmic impact on temperature according to the Beer-Lambert law and (b) the finite amount of reflected IR energy already being absorbed to extinction by the CO2 already in the atmosphere. Can someone please clarify this for me?
MC – thanks for the link : brilliant debating, just superb. Monckton, with wit and humour aplenty, describes the reduced greenhouse effect of each additional atmospheric CO2 molecule over its predecessor, so this debate is not entirely off topic. It is well worth a watch if you have a spare 80 minutes or so.
I’m not sure what claim the first sentence is based on. Can the writer elaborate?
My initial thoughts when I look at the post. The current radiative forcing at top of atmosphere from 380ppm of CO2 is around 1.7W/m^2 and from all increases in “greenhouse” gases = 2.4W/m^2. What I would call “non-controversial physics”, because it nicely ignores the rest of climate effects – the radiative-convective effect in isolation.
When you calculate the “rule of thumb” surface temperature increase from these 2 numbers above from the Stefan-Boltzmann equation you get 0.5’C and 0.7’C increase in surface temperature respectively. This is without feedbacks. You can see this all laid out in CO2 – An Insignificant Trace Gas? Part Seven – The Boring Numbers
But these are just rules of thumb – a “ready reckoner” approach to save standing in the long queue for the GCM each time you want to know something..
As far as I understand the point of this post, the climate modeling community is wrong because the current temperature increase isn’t 0.5’C x 2 or 0.7’C x 2 ?
I have my skepticisms about the climate models, but is this critique based on what climate modelers say? Is there a paper to reference?
The water vapor feedback is perhaps one critical aspect of climate models.
Do climate modelers presume it linear from pre-industrial times?
Do they calculate it to be linear from pre-industrial times?
I don’t know the answer. There seems a presumption in the article but no reference. It would be nice to check.
A few extra notes on the boring detail..
2. Where did “Carbon dioxide contributes 10% of the effect” come from? Kiehl and Trenberth (1997) calculate CO2 as about 26% of the “greenhouse” effect (see CO2- An Insignificant Trace Gas? – Part Five
3. Where does the forcing calculation in the 2nd graph come from and what is it saying?
The IPCC, effectively quoting Myhre (1998), says radiative forcing at top of atmosphere = 5.35x ln(C/Co), where Co is industrial levels of CO2, 278ppm. It is specified in boring detail (see it at the http://scienceofdoom.com reference above) and tells us the expected addition to radiative surface forcing.
This 2nd graph says “Net downwards forcing” – at surface? at TOA? And is this after feedback, before feedback?
Please can we all play nicely!
Contrast the comment by Antonia (02:14:59), which attempts to get more information from Richard Telford, with the following one from Ronaldo (02:17:36) which is guaranteed to kill any serious discussion.
What’s the point of the nastiness? It doesn’t help anyone.
“The whole AGW belief system is based upon positive water vapour feedback starting from the pre-industrial level of 280 ppm and not before.”
This is just assertion. No reference, no cite. It’s a fabrication.
Positive feedback, assumed by the AGW hypothesis, can’t just kick in today or at 280ppm: it would have to apply at all CO2 concentrations if such feedback exists. If every 20ppm CO2 causes 0.46 degC warming, then this would hold for concentrations below the level of today, and because of the logarithmic effect, each 20ppm reduction in CO2 concentration would give a monotonically increasing effect on cooling (lack of heating). So going down to the so-called pre-industrial level of 280ppm would appear to knock out about 2.5 degC of heating, if this positive feedback be true.
The fourth graph says it all, if your calculations are correct: the cumulative effect declines to zero at around 280ppm. No – that can’t be right: any cumulative effect must go through the origin: there can be no good reason why positive feedback would kick in at 280ppm. I would expect to see the cumulative effect starting at the X-Y axes origin and monotonically increasing with CO2 concentration, BUT with the increase in the cumulative temperature per 20ppm CO2 decreasing with increasing CO2 concentration.
Bill Tuttle (02:43:21) :
Then why do their models produce an algebraic result?
Reply: Do you mean arithmetic? ~ ctm
Yup — thanks, Charles.
Too little sleep from enjoying the celebratory tracer fire over here last night…
There does appear to be some question as to the actual, say 1880, level of atmospheric CO2. At the Air vent blog http://noconsensus.wordpress.com/2010/03/06/historic-variations-in-co2-measurements/ points out that perhaps that generally accepted figure of 280ppm, may be too low a figure. If we are questioning assumptions, then this seems to be one that needs rechecking.
Where do the numbers in the second graph, indicating CO2 contributing over 250W/m2 to the downward forcing, come from. These two papers
http://www.webpages.uidaho.edu/~vonw/pubs/TownEtAl_2005.pdf
http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
which describe experiments which used spectral analysis of downward longwave radiation to determine the contribution of the various GHGs to the total signal, show that CO2 doesn’t contribute more than 35W/m2 at its most active range and would likely be below 10W/m2 throughout most of the Tropics and Subtropics.
A great post by David; of course the effect of increasing CO2 on temperature has been known to be miniscule by the IPCC because that is why they have invented the enhanced Greenhouse effect which depends on the slight warming from increased CO2 releasing water into the atmosphere with its much greater greenhouse effect.
This is wrong on many levels despite Mr Telford’s typical warmist snark. First there has not been increased levels of water going into the atmosphere; Paltridge’s excellent paper establishes that with the ghost in the machine of Miskolczi present in the stability of optical depth over the enhanced greenhouse period.
Secondly, the role of clouds has been profoundly misunderstood by AGW proponents; the recent Pinker et al dispute between Monckton and Lambert in their Sydney debate shows this; the SW flux findings of Pinker, most likely caused by cloud variation, are sufficient to explain recent warming. In this respect Monckton, despite misunderstanding cloud forcing, was correct about climate sensitivity to increases of CO2; this tiny CS from ^CO2 must be based on the log effect described by Archibald and this fact coupled with the moderating role water plays against temperature movement in any direction fundamentally contradicts AGW.
sHx (01:06:52) :
Refer the MODTRANS facility, University Of Chicago.
Alarmists will tell you that the climate is far more sensitive than Archibad suggests, however I’ve never seen a convincing argument for *why*
Heber Rizzo (02:05:53) :
Please do. If you email me at david.archibald @ westnet.com.au ,
I can send you the original.
“Plant growth shuts down at 150 ppm”
Try telling that to Mr 350.
Great News: Over the past 140 years the British weather observatory situated in the Himalayas revealed a temperature drop of .4 degrees
http://www.hindustantimes.com/india-news/northindia/Global-Warming-has-no-impact-on-Himalayas-claims-Wadia-Director/Article1-515763.aspx
Senior scientists at the Wadia Institute of Himalayan Geology (WITG) has rejected the Global Warming Theory and told that the Himalayas are quite safer zone on earth, where Global Warming has no role in controlling the conditions. They also said that the conditions of Himalayas are controlled by the winter snowfall rather than external factors like much hyped Global Warming.
So a doubling of CO2 relative to pre-industrial times leads to an increase of 2W/m2. The difference between the solar minima and solar maxima IIRC is about that much.
Just in case you missed it, more over enthusiasm from the IPCC on CO2.
http://www.fysast.uu.se/ges/en/headline-news/new-research-questions-the-ipcc
God save me from scientists and pseudo scientists, you are all as bad, if you are so concerned about the environment then for goodness sake do something practical eg dont buy biscuits or anything else that uses palm oil.
50,000 Orang Utans have already been sacrificed for your own personal health and wellbeing before you even consider the average Americans concern about the cash in his pocket, palm oil being the cheapest vegetable oil available, then if you moan about water shortage then consider that it takes 14000 litres of fresh water to make one litre of biofuel.
Who for goodness sake cares whether or not Co2 is logarithmic or suffers from attention deficit disorder and maybe subject to rabies, what we do know is that none one single prediction made by the IPCC, Gore or Hansen has come true therefore commonsense would clearly indicate that its all hot air and that only someone severely retarded would want to continue this idiotic debate rather than actually do someone about the absolute destruction of our environment.
Americans should eat less hamburgers not because cows belch but because more rainforest is destroyed each year just to fuel the average Americans desire to cheap subsidised food.
Get your face out of the screen, go out and let some daylight into your challenged brains and recognise that none of you bellacheing about pointless statistics well change anything or is your chosen sense of status more important that the biodiversity that you think will be saved by your craven indulgence?
Get a life, you only have one so make use of it.
David Wells
I would urge WUWT readers to take anything written by David Archibald with a large pinch of salt.
The main (only) point of debate between responsible sceptics and AGWers concerns feeback. Sceptics think it’s likely to be small or even negative – AGWers think it will be large and positive.
David A says “ Carbon dioxide contributes 10% of the effect so that is 3° C . This is rubbish. Jack Barrrett, a leading expert in spectroscopy – and a sceptic (see http://www.barrettbellamyclimate.com/page3.htm ) reckons the effect of CO2 is more like 9 deg (see the link to his paper on Warwick Hughes site). In fact David Archibald’s own graphs suggest his numbers are wrong. The Modtran plots show the net downward forcing increasing by ~25 w/m2 (~235 w/m2 -> ~260 w/m2) due to the current concentration of CO2.
Is David saying that 25 w/m2 only equates to a 3 deg rise?
How does that square with his claims that weaker solar output will result in a temperature decline of ~2 deg over the next “few years”. TSI measurements show that the sun’s output varies by ~0.1% or ~0.24 w/m2 at the earth’s surface.
In this WUWT post, Richard Lindzen estimates 1 deg increase from a doubling of CO2
http://wattsupwiththat.com/2009/03/30/lindzen-on-negative-climate-feedback/
Here, Jack Barrett calculates an increase of ~1.3 deg
http://www.barrettbellamyclimate.com/page45.htm
There are many other reputable (not AGW) scientists who say much the same. If the feedback effect is small (or negative) then we don’t have a problem and it’s quite possible that natural variation will ‘hide’ most of the effect. CO2 will, though, have an effect. There are also very good reasons that continuing to add CO2 will not, as David says result in the effect being ‘tuckered out’, but result rather in indefinite warming. I’m not prepared to go into that now, though.
This effect is the opposite of a “tipping point.” More like a “disappearing effect.”
That CO2 forcing increases logarithmically with concentration has been known for over a century. Arrhenius (1896) did the necessary calculations:
“if the quantity of carbonic acid increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression”
The IPCC are well aware of this
“Note that for CO2, RF increases logarithmically with mixing ratio” (AR4 WG1 chapter 2.3.1)
and this knowledge is implicit in all the model projections. To imply otherwise is disingenuous.
Graph 4 is simply wrong. The bar chart is warming per 20ppm increase in CO2 concentration, the line is the cumulative effect. The units of these two parts are different – the first is deg C/ppm, the second is deg C. They are incomparable.
That problem is fixed in the last plot: at least the units are the same in this figure. But there is a second problem. The natural CO2 forcing is shown without any feedbacks, whereas the anthropogenic forcing is shown with feedbacks. This is misleading. Nobody would argue that the natural changes in CO2 are not magnified by feedbacks (try to explain the glaciations without feedbacks) One can argue about the magnitude of the feedbacks. Perhaps the IPCC has them too high. Perhaps too low.
Richard Telford,
Are cloud feedbacks positive or negative?
How is it that earth’s temperature has remained in a narrow range for 600 million years, despite 2000% changes in CO2 concentration?
As a non-scientist, can anyone please explain why there is no convective heating
of the atmosphere? Are thermals due entirely to CO2 in the deserts?
Thank you, David. This one simple fact has not been repeated often enough. Dare I say it has been suppressed in the mainstream debate.
I know that most disinterested people I talk to are under the impression driven by media alarmists that as atmospheric CO2 levels increase the temperature follows in a linear, if stochastic, fashion. That is the single greatest myth behind AGW demagoguery.
Watts and others should repeat some version of this post once a month for the next decade. It can not be stated often enough!
ginckgo (04:03:44) :
So a doubling of CO2 relative to pre-industrial times leads to an increase of 2W/m2. The difference between the solar minima and solar maxima IIRC is about that much.
The doubling of CO2 relative to pre-industrial times leads to an increase od ~3.7 w/m2. When looking at the difference between soalr minima and maxima you need to look at insolation, i.e. what the earth receives, not TSI. If TSI increases by 2w/m2, the earth’s surface, on average, only receives 25% of this (think day, night, winter, summer). Of that ~30% gets reflected back to space due to the earth’s albedo. A 2 w/m2 increase in TSI equates to an increase of ~0.35 w/m2 averaged over the earth’s surface. You should take a bit more notice of Dr. Leif Svalgaard’s posts and it a little less of Dr. David Archibald’s.
Or alternatively one could be to look to ‘natural causes’. One of the better proxies is GMF (geomagnetic field)
http://www.vukcevic.talktalk.net/LFC8.htm
which not necessarily mean that GMF is either the cause or a consequence, but possibly two offsprings of the same parentage.
http://www.vukcevic.co.uk/GandF.htm
Let’s see, usually we are told by AGW skeptics that the atmosphere is too complex to understand. That the sophisticated mathematical models that run on supercomputers cannot possibly come close to the real climate. But, now we are to believe that some guy with a graphing calculator has got it all figured out! He didn’t even need calculus, just an ln x button. Think of all the tax dollars that could have been saved!
http://www.aip.org/history/climate/GCM.htm
http://www.giss.nasa.gov/research/briefs/schmidt_04/
http://www.logicalscience.com/skeptic_arguments/models-dont-work.html
http://www.grist.org/article/climate-models-are-unproven/
I have been on the receiving end of proponents’ reply to the temperature changes mentioned in the above post.
The counter argument is that we need to make a distinction between the “equilibrium” climate sensitivity, and “transient phase”. We are suppiosed to be in the transient phase at the moment, and it is argued that the climate will take centuries to settle to equilibrium. According to this argument, we would not expect to see the equilibrium conditions for a long time to come.
I have not found this to be convincing.
Even if we were to accept that the present condition is the transient en route to a much higher equilibrium, the transient should still be evident in measurement. IPCC AR3 Chapter 9 has a beautiful chart of the “big red spot”, which show how atmospheric heating above the surface is necessary to observe heating at the surface (if heating is due to radiative physics). We should be able to see the red spot forming by now (transient or not) – especially if some past warming has been attributed to CO2.
I know of no confirming measurements which do so. Some people claim that cooling in the ionosphere is evidence – but cooling in the ionosphere without warming further down does nothing to explain recent warming. In the absence of such evidence, I’d look upon the hypothesis as falsified.
Secondly, what I consider to be the unphysical argument of amplification of temperature change by positive feedback. The term “amplification” means a dimensionless constant, where a change of an input variable results in a greater change of an output variable with the same dimensions. In the case of climate sensitivity, we’re talking about units of temperature or units of radiative flux at the surface (take your pick), where a change of input results in some multiplied change, when the system eventually settles to equilibrium.
Given that amplification is dimensionless, it’s clear that there is an increase of energy from the input to the output. We need to identify and account for this energy to make a convincing case for amplification in climate sensitivy.
And this applies equally to feedback systems – without an “auxiliary” source of energy, feedback cannot amplify a signal. Trying to say it does would be like arguing that I could jump into a basket and lift myself off the ground using the handle. You might get that to work in the cyberworld of computer models, but it doesn’t work in the real world.
I’m not trying to say that amplification is wrong. I just haven’t seen the full explanation of energy flows, so references would be welcomed. And until I see this, I would tend to view amplification of the climate sensitivity as another falsified hypothesis.
There is no need to rehash the science. Real Climate attacked my graph back in October 2007 in a piece entitled “My model, used for deception”. http://www.realclimate.org/index.php/archives/2007/10/my-model-used-for-deception/
That was the seal of approval. Real Climate felt they could no longer ignore it, they had to try to counter it. Thanks guys. Without that sort of feedback, you don’t know how effective you are.
There are two sorts of IPCC scientists – the ones that fake the historical record and the modellers who generate warmings for a doubling of CO2. We hear a lot about the former but the latter are required to give credence to the alarmist projections. Looking at a graphic that Roy Spencer produced in early 2008, there are 21 model results contributing to the IPCC concensus, with the lowest warming 2.5 degrees and the median 3.5 degrees.
But it had been bugging me for a while that global warming belief system has their heating from the pre-industrial level, and not some other point. Never mind that Spencer has shown that the feedback is negative, not positive. What the AGW belief system requires is that the system is quiescent up to the pre-industrial level and then it just explodes. It requires everybody to believe in fairies at the bottom of the garden. It defies the laws of physics and nature. It is the big lie upon which the whole AGW edifice is founded.
Bill Tuttle (02:43:21) :
I think some of the answer is that if CO2 are climbing exponentially, then the log() of that is a straight line. The catch is that current CO2 levels can better be modeled, I believe (i.e. no references and I wouldn’t believe this if I were you), as a baseline plus an exponential. The log() that is quite a bit
flatter until the exponential overwhelms the baseline.
OT, but being the science blog, some of you may find these interesting, I think they are fascinating (to see next position cursor over the photo).
http://www.telegraph.co.uk/science/picture-galleries/7397841/Creepy-crawlies-Amazing-Scanning-Electron-Microscope-pictures-of-insects-and-spiders.html
Or alternatively one could look to ‘natural causes’ to account. One of the better proxies is GMF (geomagnetic field)
http://www.vukcevic.talktalk.net/LFC8.htm
which not necessarily mean that GMF is either the cause or a consequence, but possibly two offsprings of the same parentage.
http://www.vukcevic.co.uk/GandF.htm
Re: David Wells (Mar 8 04:22),
My bellyaching changed the opposition leader here in Australia and stopped the proposed ETS in it’s tracks. Why is that important? Well if the likes of Watt McIntyre Monckton et al weren’t bellyaching, you and I and our nations would be that much poorer due to these grab taxes like the ETS. Why is that important? Look at the environments in poor countries compared to well off countries. The people in poor countries don’t give a chit about the environment, they rightfully care about where their next meal will come from.
I’m guessing you made your remarks after being well informed by reading these sorts of blogs for many months now. Why aren’t you outside getting some fresh air? Or were you naughty and just quipped after reading one or two threads?
Rob:
Somewhat OT but something is odd with the GISS numbers for Mukteshwar http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=207421470003&data_set=0&num_neighbors=1
I believe Mukteshwar Ku is the location reported in the news story.
More on my note above – my comment about log(exp()) being linear above assumes a graph of the function over time – Archibald’s graphs show temperature wrt to CO2 concentration! I think models and warmists talk about a linear increase over time, this may be a major disconnect between Archibald and them!
Where Archibald has a straight line for modeled warming, it should be a log() curve (or log(baseline + exp()) as I mention before).
Here is an interesting explanation and discussion of CO2 saturation in the Physics Forum.
http://www.physicsforums.com/archive/index.php/t-174215.html
Another scientists look at this issue.
http://wrauny.blogspot.com/2009/12/global-warming-leave-co2-alone.html
A graphics from othe studies.
http://www.junkscience.com/Greenhouse/co2greenhouse-X2.png
David,
Your post is interesting, but rests on an arbitrary choice that skews the results.
Your 10% of the greenhouse effect for CO2 is an arbitrary choice, although it is within the range supported by the literature.
Going back to Ramanathan and Coakley 1978, we see that they get a wide range for CO2’s contribution to the greenhouse effect. They get between 9 and 26 percent. The range is calculated by first removing all CO2 from the atmosphere and recording surface temp (9%) then removing EVERYTHING BUT CO2 from the atmosphere (26%) This was done in a basic radiation code and has been repeatedly verified with slight variations of no more than a percent in the 30 years since R&C.
But what exactly does the 9% tell us? Unfortunately, the 9% doesn’t tell us much. Since concentrations of WV are held steady in the radiation code to get the 9% number, there is an assumption of 0 feedback for CO2. (In other words, 9% assumes that none of the WV in the atmosphere is a result of the warming caused by CO2) Since your arbitrary choice is so close to this no-feedback number it is not surprising that you get odd results when compared to climate model predictions.
If we knew the exact contribution of CO2 to the GHE, we would know the strength of feedbacks and have a pretty good estimate of climate sensitivity to CO2 doubling. Unfortunately we do not know this with the certainty you imply in this post.
So essentially your analysis proves that if you select a small effect for CO2, you will get results that support a small effect. An equally arbitrary (and equally supported) choice of 20% for CO2’s contribution would get completely different results.
David Wells
‘Get al life, you only have one so make use of it’
I am interested in this subject because it involves such a vast waste of taxpayer money which could be put to much better use. We are in a serious economic recession and out politicians want to handicap us further by imposing taxes on industries that emit CO2. I am horrified by the vast lie that is AGW.
I was brought up on David Archibald’s excellent ‘Solar Cycle 24’, and I am very grateful to have been given a copy of it by an alert friend.
The question of CO2 warming effect being logarithmic seems to me to be a crucial fundamental question. It either is, or it isn’t. Why isn’t this question discussed more often, and more emphasis not put upon the answer? The Earth’s atmosphere has been in equilibrium for the past 500 million years, and life has flourished.
We are bumping along the bottom of the amount of CO2 seen during the past 500 million years. I gather that the average amount of CO2 in the atmosphere during the past 500 million years was 2,500 ppm. Why are we now so paranoid about a mere 388 ppm. And even more paranoid about the mere 15 ppm produced by our burning of fossil fuels?
It seems to me an absurd collective madness has overtaken most of the population. Get a life? Get a grip.
The Earth’s climate has been in equilibrium for millions of years. There must be a robust mechanism that keeps it in equilibrium. CO2 has been as high as 5000ppm during the past 500 million years. There was no runaway warming. Life flourished.
I was brought up on David Archibald’s book ‘Solar Cycle 24’. It was an excellent book
David, as a skeptic who is well versed in the logarithmic nature of CO2 forcing, I dont have a clue which message you are trying to give here. The co2 range of interest is 100 to 1500 ppm, and already Arrhenius confirmed in 1906 that this leads to a 1.2 degree temperature rise for every doubling. The only debate is now about feedbacks: Is miskolczi right that tau is a constant (which means co2 is compensated by less water vapour) or is IPCC richt that that the feedback is positive. This posting is really not helping in this debate.
Yes, IPCC knows that carbon dioxide has a logarithmic effect (look for Myhre simplified expression) http://www.grida.no/climate/ipcc_tar/wg1/222.htm
So … when is this information going to be published in a peer reviewed journal?? .. OR .. has it already been published in a peer review journal?
It would seem to me that in order to make a valid claim that the IPCC scientists are cherry picking their information, alternative information needs to be published in peer reviewed journals. Granted, I’m aware of the conspiracy to block alternative information, and to prevent alternative information from getting to the mainstream. But still, you would run a better chance of making a valid claim if it were published.
I’m a staunch skeptic and find much wrong with Climate Science from a scientific perspective. However, I find myself scratching my head wondering why “science” is not driving ahead according to the accepted protocol. … Publish!
There are so many things. Station drop out, solar forcings, this issue on CO2 forcing, bad models, bad thermometers, etc etc .. but it seem little of it gets published in journals .. just internet.
HECK .. start your own journal if the tainted ones won’t publish it.
What is the real pre-industrial CO2 level? I am confused. See this webpage:
http://www.biomind.de/realCO2/
I have used this graph and argument in conversations with True Believers(tm) and the reaction is always the same: It doesn’t matter, look at the ice melt.
It is completely useless to continue to engage TBs any longer. There is literally nothing that will convince them. Even a glacier at their front door would be proof positive the “science” is right.
Focus on the the people on the fence….
Dear Dr.Archibald, stick to your brilliant approach of the Sun cycles. Greenhouse doesn´t exist, it´s dead. The so called “green-house effect” is for closed systems, it really means “trapped heat”. Our earth, HOLY GAIA for the world government conspirers believers, it is not a closed system but an open system…and, as Lord Monckton has shown, based on satellites observed energy balance, energy loss from our planet is greater than energy gain. Temperature is but an almost subjective reference.
The famous physicist Niels Bohr, at the beginning of the 20th.century described this “green-house effect” as non existing:
http://www.scribd.com/doc/28018819/Greenhouse-Niels-Bohr
David Wells (04:22:34) :
Rant much?
1. It isn’t just Americans that post in these threads, or are you truly and specifically targeting Americans for the worlds environmental issues?
2. The ‘environment’ and CO2 (in context) are two different things. Me thinks you have trouble distinguishing the two.
3. It appears you deem the ‘science as settled’: would this be the case?
4. Perhaps it is you who needs to get your ‘face out of the screen’ and go outside to see that the environment *isn’t* crumbling at our hands.
5. Did you forget to mention the evil corporations and big oil?
6. Just because you have no interest in a particular subject [science], and don’t see the relevance, doesn’t mean others don’t.
@richard Telford (01:00:29) :
“The final graph is complete junk. Comparing forcing due to CO2 alone with forcing due to CO2 + feedbacks and finding that the latter is larger is pretty trivial.”
————-
Feedbacks are infinitely complex, and the portion that deals with cloud cover, and changes in sea ice and snow cover are poorly understood. Only the water vapor aspect is well understood, and is widely agreed upon as being positive. Accurately assigning a quantity to that positive value for water vapor is another matter. There is wide disagreement (depending on which Climatologist you ask) whether cloud feedbacks due to increased CO2 forcing are positive or negative. What is known is that cloud feedbacks are highly chaotic. Feedbacks due to CO2 forcing don’t just “take off” at some imaginary threshold, but rather logically follows a more smooth curve. The idea that a diminutive increase in forcing due to an increase in atmospheric CO2 could be amplified several times by positive feedbacks (with the assumption that the positive feedbacks overwhelm the negative feedbacks) runs parallel to the concept of an over-unity perpetual motion machine, thus my skepticism. Besides that, the Stefan-Boltzmann law for radiation of a black body predicts that there is always present a strong negative feedback for any type of forcing that changes the temperature of the black body.
It would require a googolplex of data points to actually measure the feedbacks existing on the globe for a single day. Good luck with that. All we have is some limited data, fuzzy theoretical math equations, and GIGO computer models to predict feedbacks.
Here is a statement found at:
http://www.faqs.org/faqs/sci/climate-change/basics/
“These figures are compatible with the IPCC estimate of about 1.5 to 4.5 o C surface
warming for a CO2 doubling.”
The range of that estimate runs the gamut of 300% for the maxima over the minima. Nothing to see here, move along.
Someone asked for references. Here are a couple:
Bejan, Adrian; Kraus, Allan D. Heat Transfer Handbook. John Wiley & Sons., 2003 Page 618 (Leckner’s curves, available in electronic form from http://www.knovel.com)
Schumann, Reinhardt, Metallurgical Engineering, Volume 1, Addison-Wesley, 1952 (Hottel’s curves –>> note the year.)
Hottel et. al. developed a method of calculating the impact of CO2 on radiant heat transfer in the atomsphere. Leckner greatly improved on the method. Both take into account all of the “fudge factors” that relate to absorbance. Full spectra, concentration, distance, reradiation within the gas, etc. This work that was ignored by climate scientists is used by everyone else who needs to calculate radiant heat loss in the atmosphere (so many people do this even engineers like me can learn it). Applying this work to the atmosphere shows that the logarithmic relation is an approximation. A log/log relation is more likely. Anyway, the graphs of forcing one gets using these methods is similar to the f=5.35ln([CO2]/{CO2{284}). It just flattens more at higher concentrations (above 100 ppm). It does indeed prove that most radiant heat effects begin at very low levels of gas. Using this method, the maximum absorbance by CO2 would be about 45 W/m³. This is attained at about 200 ppm. (100 ppm is 40) 22.5 W/m³ is attained at about 6 ppm. If Anthony is interested, I can send him a paper I’ve written that clearly shows the method for obtaining these including sample calcs, etc. that make creating the graphs relatively trivial.
@ David Wells
I shout
he she or it shouts
we shout
they shout
You make some valid points but start a shouting match with other posters quite un-necessarily so.
The reason this and similar articles on this site have validity is because the foundation of the hypothesis that man made CO2 emissions will cause dangerous global warming is at the heart of the debate.
Finally does anyone know what the CO2 level was during the MWP and earlier warm periods?
PS Guys
A sponfull of sugar and a pint pot of gall?
Does anyone remember where that wonderful little article is which shows how much the CO2 levels have increased… by showing a graph of atmospheric gases scaled from 0 to 100%? It really puts 300 PPM in perspective.
Dave Wendt (03:19:06) :
I’ve seen elsewhere analysis of the two papers you cite as not only discussing the total intensity/amount of Long Wave Radiation, but also as documenting the lack of a measurable correlative difference in the re-radiated (outgoing) LWR given the increase of CO2 ppm in the atmosphere. In other words, as observational data that directly refutes the claims of CO2 greenhouse effects, as postulated by the AGW theory.
If something can be confirmed, via directly measurable observational data, e.g. Einstein’s prediction of the effects of gravity on light, confirmed by observations during a solar eclipse – then how is a departure from the postulation (absence of predicted behavior) not a credible refutation?
Following on from that, if the main premise is demonstrably inaccurate (in other words, wrong), how is anything based upon the hypothesis anything other than pure malarky?
CO2 – if the numbers don’t fit, you must acquit. And question why so many are so latched on to the one theoretical model that has even the slightest possibility of being influenced by the manipulation of human behavior, becomes extremely relevant, although this thread is not the appropriate venue to explore it.
Water vapor is a good greenhouse gas/vapor but water vapor in the form of clouds decreases the solar insolation.
AnonyMoose (06:09:31):
Do you mean this one? : click
Just to keep it in proportion, this is the average composition of the
atmosphere up to an altitude of 25 km.
Nitrogen N2 78.08%
Oxygen O2 20.95%
Water H2O 0 to 4% (variable, affecting total)
Argon Ar 0.93%
Carbon dioxide CO2 0.0360%
I just love someone popping in to discuss “responsible” scientists. Nonsense!
Scientists may be wrong in their theories, or correct, but if they are really scientists, the term responsible doesn’t belong in the discourse.
Referral to socially based grading of behavior is a warning flag that the discussion isn’t about science at all.
Attempts to hide data, algorithms, ad hominem attacks, referrals to discredited papers, and appeals to higher authority are all venal attempts to hide non-science, both from the lay public, and other, competent scientists.
This thread is a poster child for the Warmists method of doing business. It wouldn’t matter if the poster were wrong, it happens frequently that a scientist is wrong. The point is, scientists put everything out on the table to be viewed, right or wrong.
The method of responding is what is telling.
@AnonyMoose
It’s the dose the makes the poison, the fact that CO2 is a trace gas is not an issue. CO2 is a very strong IR absorber.
All classic strawmen are passing by.
Very informative write up.
The old painting a window glass pane with successive coats of white paint, and hoping to turn the room completely dark trick. After a few coats nothing else much happens. That’s called the logarithmic effect, once you have about three coats of paint, it’s all the paint has got that can be used to block light.
If the positive feedbacks proposed by the IPCC and their merry band of modelers, were true, the earth would be a fireball already. Once the climate ran away, or latched up, it would be stuck hot, or cold, for all time.
Watching a discovery channel presentation last week, they went all over the temperature ups and downs, the sea level ups and downs, and the CO2 levels ups and downs. It’s been far hotter than today, far colder than today, the sea levels have been 300 feet higher and 300 feet lower, the atmospheric CO2 level has been lower and much much higher than today, ice covered the whole planet, and completely melted everywhere, and we are still here. Very enlightening, here is the link … http://dsc.discovery.com/tv/prehistoric/prehistoric.html … watch if you dare.
The effect of plate tectonics was clearly shown in determining earth’s climate.
If only the media would tell the truth … scientists could get back to real science, and stop with the silly stuff. The alarmists have clearly gone past the expiration date on the public’s “Issue Attention Cycle” with their hoaxing. Time to move on.
Suggestion, next a writeup on the absorption of CO2, the lab experiments that prove it, and how it plays into this posting. May not be for the laymen though.
Wind Rider (06:12:02) :
If something can be confirmed, via directly measurable observational data, e.g. Einstein’s prediction of the effects of gravity on light, confirmed by observations during a solar eclipse
Are you sure?, That was only diffraction.
The primary global warming potential action of increasing CO2 is said to be an increase in water vapor (not clouds, water vapor) due to the warmer air. Show me one graph that demonstrates a significant and increasing trend in water vapor that lies outside what is expected to occur during natural water vapor increasing events (IE El Nino, warm PDO, etc). Without increasing water vapor, the AGW theory and the models are proven false.
Just to remember some facts:
Facts about CO2:
CO2 it is not black, but trasparent and invisible
CO2 is the gas you exhale. You exhale about 900 grams a day of CO2
CO2 that you exhale is what plants breath to give you back O2 (oxygen) for you to breath.
CO2 is heavier than air, it doesn´t fly up, up and away CO2 is a trace gas in the atmosphere, it is the 0.038 per cent of it, or 3.8 parts per ten thousand.
The atmosphere, the air you know, does not have the capacity to “hold” enough heat, it only “saves” 0.001297 joules per cubic centimeter, while water , the sea you know, has 3227 times that capacity (4.186 joules).
Would you warm your feet with a bottle filled with air or filled with hot water?
Hans Erren (06:23:17) :
“It’s the dose the makes the poison, the fact that CO2 is a trace gas is not an issue.”
That seems to be a contradiction. What am I missing?
The first sentence starts with a misrepresentation.
It is not “greenhouse gases in the atmosphere” which raise the temperature of the planet above the -15° average calculated for a planet at our distance from the local star, but the ability of the atmosphere to absorb heat by conduction from the surface and distribute it around the globe in an attempt to establish homogeneity.
The presence of any atmosphere, with or without attendant greenhouse gases, would accomplish this to some degree.
It is the lack of a fluid atmosphere with this ability which causes the temperatures on the Moon to range from -233° to +123° over the diurnal cycle.
The greenhouse gases play a minor role in radiative blocking, but not nearly enough to account for the 30° difference between here and the Moon.
Second potential falsification:
The primary global warming potential action of increasing CO2 is said to be an increase in water vapor (not clouds, water vapor) due to the warmer air. Show me one graph that demonstrates a diminution of OLR (a growing imbalance between incoming shortwave and outgoing long wave infrared radiation) that lies outside what is expected to occur during natural events. Without decreasing LWR, the AGW theory and the models are proven false.
The CO2 AGW theory, as it stands, can be tested with measurements beyond temperature.
I’m a bit confused with the pre-industrial CO2 levels as well. Actually up to about say 1979.
The measurement done was that for the summer or winter deposits of CO2? What with the winter levels not being so high.
And with what we supposedly know now about CO2, it mostly being concentrated in a couple of streaks around Earth hiking the trade winds and jets streams, isn’t it then kind of looney to rely on measurements from the ever so central place called antarctica, well central for birds that can’t fly anyway?
Dear Dr. Archibald,
CO2 in Icecores in no way reliably represents the original atmospheric CO2 level because of fractional processes. The fossil leaf stomata indices for example show CO2 concentrations between 270ppm and 326 ppmv while the Taylor Dome icecore showed only concentrations between 260 and 264 ppmv in the last 6000 years. the chemical measurements of CO2 in the 19th century showed values up 420 ppmv.
As most plants receive more CO2 than the present day concentration they grow faster and fatter. In order to do that they must be absorbing solar radiation and converting it into potential chemical energy, (fats and sugars, etc.), at a faster rate. Such conversion by photosynthesis could be represented as ‘lost heat’ in the earth radiation budget in that radiation that arrives at the surface then ‘disappears’ from the equation. (Any satellite image you look at shows the vegated / rural areas as much darker than the cities even though they are always cooler than the cities. (Transpiration only can go so far to explain the difference IMO.)
I wonder then, given CO2’s logarithmic, ‘diminishing return’, nature, could the above negative feedback of photosynthetic radiation loss, at some higher PPM concentration, utltimately overtake CO2’s GHG effect on an incremental basis?
The problem is, the first sentence is not correct (in my opinion).
1) 33K is not correct, because it is calculated with present albedo. 70% of present albedo is created by clouds, which should not be there since the hypothetical Earth got no “greenhouse gases”. With cloudless Earth, the difference should be some 15K. (I will not go further, considering that such Earth can not have oceans and should be more Moon-like etc.)
2) Presence of greenhouse gases expects existence of oceans and clouds. Clouds cools Earth. Condensed water vapor rains on the surface and cools it by evaporation. Oceans absorb a lot of heat, effectively cooling the surface again. Net effect of “greenhouse gases”, mainly water in various forms, is cooling effect.
3) Earth is warmer, because it has atmosphere consisting of 99% nitrogen and oxygen. Atmosphere absorbs and keeps heat, therefore our night is not as cold as on the Moon. Also, our days is not as hot as on the Moon.
4) Mars has thin atmosphere consisting of 95% CO2, and its temperature is equal to the theoretical value 210K. Its effective CO2 concentration is roughly equal to water vapor + CO2 on Earth, but has no visible effect. Venus has dense atmosphere consisting of 95% CO2, and its temperature is very high. However, Venus is both closer to the Sun and has much higher surface pressure. Its temperature in 1bar altitude, corrected for its Sun proximity, yields average Earth temperature again. –> It does not matter much, from what is the atmosphere composed, but how much of it is present.
5) I believe water vapor has dampening effect, warming nights and cooling days, but thats all. There is no increased “greenhouse effect” observed in polar regions, where is only a little humidity and rising CO2 should increase temperatures by far most. “GH” effect causing +33K is theoretical construction, which wrongly attributes observed reality. How can you recognize IR radiation coming from 300ppm CO2, compared to radiation, emitted by 900,000 ppm warm oxygen and nitrogen?
In case I am wrong, either there are negative effects swallowing all the CO2 addition or per Miskolczi, total “GH” effect is constant, modulated by changes in water vapor.
How does an individual assess competing claims on an issue of this complexity? You’ve got to have sympathy with the journalists who basically say “whoa, this biologist from Stanford must know what he’s talking about.” Of course with a little historical perspective we can remember that the entire academic world of Geology was wrong about plate tectonics a few decades ago… In the case of AGW even looking at temperatures doesn’t really help that much because “weather is not climate” and in my opinion even if it started decisively heating up again, that still wouldn’t indicate that greenhouse gases emitted by human activity had anything to do with it, necessarily. It’s a vexing question.
>>
. . . (the Holocene is an interglacial in the ice age that started three million years ago).
<<
I think it’s more like 12,000 years ago. The current ice age 100,000 year cycle (with 10,000-20,000 year interglacials) started about 2-4 million years ago.
Jim
@Smokey,
You are missing that a little bit of CO2 can block a lot of infrared radiation, just like a little bit of arsenic kan kill a lot of rats.
But, But, CO2 behaves logarithmically!
Sure, we knew that.
David,
a missed ‘key’ here is the same concept for h2o vapor. Absolute humidity again is a log function. If you assume an increase – say 5K and recompute absolute humidity based upon the standard climate assumption of constant relative humidity, you’ll find there is an increase of 0.3 in absolute humidity. This is far less than a doubling. Note that h2o has much higher concentrations than does co2 and it is much more potent. I haven’t used archer’s modtran calculator to manipulate h2o content but I’ve got my on 1-d model. H2o effects are around 8-10 w/m^2 increase for a doubling versus 3.7 w/m^2 for a co2 doubling.
The net results indicate that a 5 deg C increase in temperature results in less forcing than a co2 doubling. That means we’re missing over 3 deg C of warming to achieve that 5 deg C rise after accounting for h2o vapor and co2 – ignoring additional cloud formation etc. Try it for a 2 deg C rise and you’ve got the same problem, co2 doubling is good for less than 1 deg C on its own and a 2 deg C rise will support much less than a 5 deg C rise – which was roughly comparable to co2 but a little less. For 2 deg C rise, we’re still missing almost half of the necessary forcing as the h2o is going to contribute only about 1/3 what a co2 doubling does.
don’t look now but they’re trying to move the goal posts. the extra will be the methane beast that they didn’t know know about in any quantitative fashion (and still don’t) and didn’t program their models for – the ones that promise 5 deg C rises. LOL
I would edit this sentence:
“The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere…”
to say:
“Insolating gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere…”
I like the analogy of the earth as hot water bottle over the earth as a greenhouse…I think the hot water bottle is more accurate.
Mike (04:54:41) “…That the sophisticated mathematical models that run on supercomputers ….”
You mean the ones that run “a href=”http://www.americanthinker.com/2009/11/crus_source_code_climategate_r.html”>code like this? –
yrloc=[1400,findgen(19)*5.+1904]
valadj=[0.,0.,0.,0.,0.,-0.1,-0.25,-0.3,0.,-0.1,0.3,0.8,1.2,1.7,2.5,2.6,2.6,2.6,2.6,2.6]*0.75 ; fudge factor
Oops, can I retract that? That was dumb, here’s what I meant to say…
I would edit this sentence:
“The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere…”
to say:
“Insolating gasses keep the Earth 30° C warmer than it would otherwise be without an atmosphere…”
I like the analogy of the earth as hot water bottle over the earth as a greenhouse…I think the hot water bottle is more accurate and the CO2 component contributes an interesting added warming effect, but it is small compared to how the sun heats water, and the water then heats the atmosphere.
With that global warming is like religion, except that
forsy church picks from ordinary people, and the spec from GLOBAL WARMING
want to cut the cash already WHOLE COUNTRY, a much higher driving school:)
I have a great deal of sympathy with the view taken by Mari Warcwm 05 41 01 .As with so many things, money seems to hold sway over common sense. In the UK we have a government which is practically bankrupt proposing to spend millions we do not have on wind farms which will not work. They also plan to bury CO2 under the North Sea – another Green dream which has already been shown to be impossible.
The AGW pseudo science is so deeply entrenched in money that scientific argument will never shift it.
According to James Delingpole the BBC Pension Fund has £8 Billion invested in the Institutional Investors Group on Climate Change – other people similarly misled include several County Councils and other Pension Funds.
This probably explains the BBC’s reluctance to see the light. To know Just how many more of our sources of information are tainted in this and similar ways would be most interesting.
I find these graphs to be of great use in explaining what David is talking about.
http://www.globalwarmingart.com/wiki/File:Solar_Spectrum_png
http://upload.wikimedia.org/wikipedia/commons/7/7c/Atmospheric_Transmission.png
and
http://wattsupwiththat.files.wordpress.com/2009/02/eia_co2_contributions_table3.png
First there is very little extra energy available to be absorbed by CO2 as seen in the first two graphs. That is what the logarithmic relationship is all about.
Second H2O is a much bigger player as seen by the total amount of energy absorbed by H2O vs that absorbed by CO2.
Then you must add in the amount of water vapor vs the amount of CO2 in the atmosphere and the tremendous variability in the amount of water in the atmosphere by location and time.
Finally there is the percentage of CO2 generated by mankind (3.1%) compared to the total annual amount of CO2 produced. ( Mankind 23,100 million metric tons/yr vs a total of 793,100 million metric tons/yr.)
Catastrophic Mann-made Global Warming is laughable when you actually look at the facts. I do not care what type of multiplier “forcings” the IPCC and climate scientists try to conjure up to explain how a minuscule amount of man-emitted CO2 is going to make the sky fall.
Hans Erren (07:00:00) :
Yes, this is true. However once they’re dead, adding more arsenic doesn’t make them more dead.
Hans Erren (07:00:00):
“But, But, CO2 behaves logarithmically!
Sure, we knew that.”
Thanks for pointing out that an increase in that minor trace gas can not cause runaway global warming. In fact, we do know that.
JonesII
Thank you for the link to hhtp/www.scribd.com/doc/28018819/Greenhouse-Niels-Bohr.
The articel was very illuminating, and I particularly liked the image of ‘Trapping IR with CO2 would be like trapping mice with a chain link fence.’
Mike (04:54:41) :
“Let’s see, usually we are told by AGW skeptics that the atmosphere is too complex to understand. That the sophisticated mathematical models that run on supercomputers cannot possibly come close to the real climate.”
The basic physics of the effect of CO2 is well known and well documented.
All other things being equal a doubling of CO2 gives you somewhere in the neighborhood of a 1 degree C rise in temperature. There isn’t any scientific disagreement on this point.
Where the disagreements are is what happens to other things if one raises the tempurature 1 degree C.
Does the amount of the water vapor substantially change? Does the water vapor end up as clouds? Does the water vapor end up as snow? If the earth warms by 1 degree ‘C’ do substantial amounts of methane get released from frozen bogs?
The AGW’ers believe that the earth is very senstive and a minor change in one variable will cause catastrophic changes in other variables.
They also believe that a major change in demand for fossil fuels will not cause a major change in the cost relationships between fossil fuel energy and non-fossil fuel energy.
To get a doubling of Atmospheric CO2 we need to be emitting at the 60 Gigaton a year rate, but we are only emitting at the 30 Gigaton a year rate.
Somehow in the magical world of an AGW’er, humanity doubles its demand for fossil fuels, but the price relationship between coal,natural gas,oil,wind,nuclear and solar stays the same, so government intervention is required.
David I completely agree with the gist of your post
David Archibald (05:09:20) :
The entire CO2 question is really a political and worldview struggle. The current “Global Warming” group are true religious believers and likely composed of a majority of people who long for a completely different social system. I suspect they desperately hate the petroleum industry and their real goal is to shift financial and political power to a paradigm that fits their definition of acceptability; the financial, economic and human induced harm be damned.
I enjoyed your post, it makes sense to me but even if you are completely wrong it makes little difference to the real struggle at hand. For the sake of real science and openness, the current gate-keepers of the global warming religion must be defeated. Their corruption of the spirit of science must be relegated to the dust bin of history along with the carpetbaggers that ride their coattails.
Keep up the good fight.
Has anyone taken a chalk in his/her hands?. Well, you know it comes from the trillions of lime (calcium carbonate, chalck) deposits all over the earth. Wanna know fossil CO2? just see those inmense deposits: They TELL YOU how much CO2 there was in the past. See?. Well, all the rest is but the expression of a dying subculture, of naive ideologies, a product of too much hemp in the 1960’s. All those “philosophies” have taken you to the state of affairs that you msm qualifies as an inminent, and yours only to enjoy,”armageddon”.
As I understand the process at the primary sampling station for CO2 at Mauna Loa, a sampling tube is purged with inert gas and then a sample of air is drawn.
This sample is measured spectrographically and the daily results are added; has anyone ever established that the purging is fool-proof?
Has any study ever investigated the accuracy and reliability of the sampling process?
This graph is the grail — the foundation itself.
I would hate to learn that it gets dirty like my rain gauge.
******
Richard Telford (04:39:45) :
The natural CO2 forcing is shown without any feedbacks, whereas the anthropogenic forcing is shown with feedbacks. This is misleading. Nobody would argue that the natural changes in CO2 are not magnified by feedbacks (try to explain the glaciations without feedbacks) One can argue about the magnitude of the feedbacks.
******
Ice-albedo feedback is the major feedback during glacial transitions. This feedback is having little affect now because the remaining glacial ice @ Greenland & Antarctica is at such high latitudes that relatively little sunlight is reflected (and hence our relatively stable temps during interglacials). Only when cold periods occur often enough and/or snowfall increases that snowcover survives much of the summer at lower latitudes will the ice-albedo affect become significant. No changes in CO2 are required — the CO2 changes during glacial transitions are the result of ocean in/outgassing from temp changes, not the other way around.
Do not be deceived by professionals from the European
narrative tales.
Pamela Gray (06:31:46) :
“Without decreasing LWR, the AGW theory and the models are proven false.”
The average LWR has not been decreasing, and there seems to be little correlation between outgoing LWR and the troposphere temperature: click
Some have decried why conventional media outlets don’t pick up on stories like this. Regardless of the merits of the article, the fact is that a good portion of the journalists and reporters get befuddled and have their eyes glaze over at the word “feedback” much less “logarithmic.” In other words, they don’t know how to write up their stories because they forgot all that “stuff” from High School and they don’t think anyone will read it.
Excellent article but I still have problem with the base methodology of deriving from a mixed gas even the reduced level of GWG attributed to 0.002% increments of the composite mixture.
To call this an empirical derivation is ‘I think’ misleading. There may not be supercomputers involved but there are still a lot of assumptions of understanding … you could say derivations based on a ‘model’.
My preference is to simply strike this term in the equation to 0 (or insignificant) given we consider the ‘base case’ (0 on ‘y axis’) the suffocation of plant life and not even consider what happens below ~200 ppm (0.02%).
Thanks for the like Mari.
Smokey,
Theoretically it could depending on the feedback factor. But if we would have that strong feedbackfactor, the earth would already have ran away, but it didn’t, so it isn’t.
Sorry, thanks for the LINK Mari.
hhtp/www.scribd.com/doc/28018819/Greenhouse-Niels-Bohr
True, CO2 increases should have a roughly logarithmic effect, but water vapor feedback should ALSO have a logarithmic effect. I think that’s one item missing in their logic when the Catastrophic Anthropogenic Global Warmers present their apocalyptic scenarios.
About 4.6 billion years ago, the sun was roughly 70% as luminous as it is now. Using a linear extrapolation of luminosity increase, the sun must have been only 75% as luminous as it is now at 3.8 billion years ago, yet by that time the world had oceans and life, and a mostly nitrogen atmosphere, as it does now. OBVIOUSLY the feedbacks must be mostly negative, probably due to clouds, else the world’s oceans would have boiled away billions of years ago, else the earth would have been a frozen, lifeless slab 3.8 billion years ago.
Here is a short, animated PowerPoint Show with audio to illustrate why the “greenhouse” effect of CO2 is roughly logarithmic. The 15 micron band of radiation from the Earth reached 100% absorption when CO2 rose to nearly 300 ppmv prior to the industrial age. That is why the roughly 100 ppmv added by recent human activities has had a minimal effect. Even if CO2 goes up another 100 ppmv, to 500 ppmv over the next 50 years or so, the effect will be minimal. This is compatible with David Archibald’s charts.
A longer version of the above, showing why human-caused “global Warming” is not a crisis and why water vapor most likely has a net negative feedback, is available here.
Henry @ David Archibald
Sorry, but I am not sure where this information comes from that
“Carbon dioxide contributes 10% of the effect ”
first of all, how do we know for sure that CO2 is a greenhouse gas?
The trick they used (to convince us) is to put a light bulb on a vessel with 100% CO2.
But that is not the right kind of testing.
You must look at the spectral data. Then you will notice that CO2 has absorption in the 14-15 um range causing some warming (by re-radiating earthshine) but it also has a number of absorptions in the 0-5 um range causing cooling (by re-radiating sunshine). So how much cooling and how much warming is caused by the CO2? How was the experiment done to determine this and where are the test results?
Hans Erren (05:43:53) :
David, as a skeptic who is well versed in the logarithmic nature of CO2 forcing, I dont have a clue which message you are trying to give here. The co2 range of interest is 100 to 1500 ppm, and already Arrhenius confirmed in 1906 that this leads to a 1.2 degree temperature rise for every doubling. The only debate is now about feedbacks: Is miskolczi right that tau is a constant (which means co2 is compensated by less water vapour) or is IPCC richt that that the feedback is positive. This posting is really not helping in this debate.
Yes, IPCC knows that carbon dioxide has a logarithmic effect (look for Myhre simplified expression) http://www.grida.no/climate/ipcc_tar/wg1/222.htm
Hans
Thanks for your contribution. I fear it will do little good, though. David’s argument is similar to many that were being put forward on ‘maverick’ blogs when I first starting looking into AGW several years ago. Eventually you learn to filter out this sort of rubbish.
Of course we know that the CO2 effect is logarithmic. There is no-one on either side of the debate who doesn’t acknowledge this. I, like you, am not sure what David’s motivation for this post is (another book perhaps?)
Anyone who thinks that the effect of COO2 in the atmospehere in insignificant should take a look at emission spectra graphs. Steve McIntyre looked into the issue a couple of years ago. See
http://climateaudit.org/2008/01/08/sir-john-houghton-on-the-enhanced-greenhouse-effect/
In this post, he included a graph which showed a comarison of theoretical and observed radiances for a clear atmosphete at 15N; 215W (see Fig 3). Steve makes the following comment
John Eggert (06:07:51) :
“…. If Anthony is interested, I can send him a paper I’ve written that clearly shows the method for obtaining these including sample calcs, etc. that make creating the graphs relatively trivial.”
I do not know about Anthony, but anything that helps clarify the science for the rest of us is much appreciated.
The temperature sensitivity of CO2 is clearly not logarithmic over the entire range. The logarithmic relationship appears to range from about 40ppm to about 200ppm. After that it looks more like a 1/x type relationship. Maybe the whole curve is closer to 1/x. Has anyone tried doing such a plot?
A logarithmic curve is a 1/x curve (roughly) over narrow ranges.
Do they still teach algebra in high school?
Would it not be relatively simple to create practical experiments to show the effect of different levels of greenhouse gasses – or has this already been tried and, if so, what were the results?
The BBC made a simplistic experiment to “prove” that higher C02 “caused warming” during Copenhagen by heating 2 plasic bottles of “atmosphere”, one with more C02 than the other, with two electric light bulbs. There was no measurement of the amount of C02 being used or the relative heat of the 2 bulbs so the experiment imho was useless. The temparature of both bottles shot up with the increase in the one with the higher C02 being slightly ahead of the other. My conclusion was that the main reason for the increase in heat was the light bulb (“sun”?), not the C02 but the audience appeared to be convinced.
If no experiments have been performed, would it be possible to create containers with exactly the same atmospheres in them but then add extra levels of ppm of C02 and/or other trace gasses to certain containers and then observe what happened naturally to the temperatures of each container over time ?
A better link than above and a nice short description of the origins of this discussion … Arrhenius vs Bohr.
http://my.telegraph.co.uk/reasonmclucus/blog/2009/02/07/greenhouse_theory_disproved_a_century_ago
I haven’t seen anything that would keep me from ignoring this whole ‘effect’ and striking CO2 in the equation to zero.
The enhanced greenhouse effect appears to be a misnomer, because the positive feedbacks do not appear to be caused by the c02, but caused by the rise in temperature caused by the co2 (or am I missing something?). This would suggest that any temperature increase causes an increased temperature (i.e. the sun warms up slightly causing water vapour to increse and icebergs to recede etc. etc.)
Systems that exhibit this phenomena in electronics are described as having hysteresis (they tend to lock at their maxima or minima, and are used to remove noise when moving from an analog to a digital world). It seems bizarre for scientists to be characterizing a natural system to be exhibiting more positive feedback than negative – at least without defining when the negative feedback will kick in.
Any computer model with a little bit of excess positive feedback is going to predict whatever it is modelling is going to hell in a handcart over sufficient iterations. These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.
John Finn (08:00:45) The large notch or “funnel” in the spectrum is due to “high cold” emissions from tropopause CO2 in the main CO2 band. CO2 emissions (from the perspective of someone in space) are the coldest.
And how is this differentiated from a gas mixture with no CO2, in determining this effect? How do you remove all the other explanations for the observed behaviour of a mixed gas? I have yet to see a ‘controlled experiment’ that cleanly shows this exists and on the surface the very idea of this massive energy foci appears implausible. Something else is going on and only the ‘political focus’ on CO2 becomes self evident the more you dig down into this subject. That is a very interesting (old) story in itself.
Why is there an assumption that CO2 dispersion, inbound solar energy, and outbound LWR – are spatially uniform?
Mike M (06:46:15) :
“As most plants receive more CO2 than the present day concentration they grow faster and fatter….
I wonder then, given CO2’s logarithmic, ‘diminishing return’, nature, could the above negative feedback of photosynthetic radiation loss, at some higher PPM concentration, utltimately overtake CO2’s GHG effect on an incremental basis?”
I love it. A provable negative feedback effect from increasing CO2. Mann-made CO2 causes GLOBAL COOLING. I guess we will have to keep this one under raps or the political types will use it when the climate turns cooler for the next 30 yrs.
@ScientistForTruth:
“No – that can’t be right: any cumulative effect must go through the origin: there can be no good reason why positive feedback would kick in at 280ppm.”
Actually, there can. Around that level, most of the moisture in the atmosphere today would have precipitated out as snow due to the cold, i.e. what happens when you are in a death spiral headed toward an Ice Age, the poles, where most of the warming happens, would be bone dry in the atmosphere, any atmospheric moisture would come from polar ice evaporating due to low vapor pressure. What we need to see is a similar curve for the forcing of H2O (according to whatever law it behaves by, linear, log, geometric, etc) along with what temperature to expect each given level of atmospheric H2O.
Some say H2O is negative forcing in its sensitivity, others say positive. If it were truly, solidly negative, then a H2O rise will always be the trigger of a new ice age, but ice cores don’t reflect that, instead you see slow CO2 drawdowns causing gradual cooling over thousands of years (excepting freshwater injection events like LD, but those only happen at the end of a glaciation, not the start). If it were truly positive, then a H2O rise like that were seeing would always be the trigger of a catastrophic flooding of the globe, but we don’t see that either, the only catastrophic floodings happen at the end of glaciations (draining Agaziz, filling the Med, the Red, and the Black seas..) .
Because atmospheric water vapor both cools during the day, and reduces cooling at night, its more fair to say that increased water vapor is going to increase volatility in climate in both directions, which I believe is what most middle of the road climate folk believe anyways. The big question in dispute is how sensitive H2O is to CO2 levels.
Is anyone out there thinking?
CO2 is a gas found in the atmosphere. As is true of many molecules, CO2 responds to certain incoming radiation (photons) by jumping to an excited state. I am citing the obvious here. What then? Does the CO2 remain excited forever? No. The excited state decays back to an unexcited state, releasing the quantum of energy (this time without regard to direction).
The absorbed energy CANNOT remain in the atmosphere, in excited CO2 molecules. In the outgoing energy from earth, only a certain portion is found in energy levels to which CO2 responds. It is kind of like a food fight. If one CO2 molecule gets the photon, another one does not. So distributing the energy among more CO2 molecules means (inevitably) that fewer of them (proportionally) will be excited.
This non-equation view should suffice to explain why there cannot be a linear relation between CO2 concentration and infrared absorption and re-radiation.
Looked at from a statistical perspective, such a relation is tailor-made for a logarithmic relation.
And that is what the data shows.
That first 20 PPM of CO2 ALL get excited.
But saturation sets in. In fact I would suggest exploring the logistic curve as an even better model.
Oh, well. I am not being paid by any oil companies, so I have nothing to prove.
Hans Erren (07:00:00) :
Perhaps ou need to get away from the poison angle and take the life giving approach: that trace of CO2 supports all life on the planet without it (and water) the planet would be be lifeless.
I just like this perspective better.
Well………it can be green house effect can increase exponentially in later days……….Am worried and everyone
IMHO it all comes down to feedbacks. A doubling of CO2, by itself, would cause warming of about 1C. The IPCC predicts a much greater increase of up to 6C based on climate models. But all of their climate models assume there are positive feedbacks which amplify the effect of the CO2. Professor Richard Lindzen in his paper “Deconstructing Global Warming” shows that the overall feedback is in fact negative. http://www.globalwarming.org/wp-content/uploads/2009/10/lindzen-talk-pdf.pdf
That paper is based on measurement of radiant energy leaving the earth, not on modeling assumptions.
Positive feedbacks imply an unstable climate that would be prone to going into a runaway effect. A negative feedback implies that the earth has a natural regulating system which tends to stabilize temperature.
Ken Roberts (07:41:04) :
“As I understand the process at the primary sampling station for CO2 at Mauna Loa, a sampling tube is purged with inert gas and then a sample of air is drawn.
This sample is measured spectrographically and the daily results are added; has anyone ever established that the purging is fool-proof?
Has any study ever investigated the accuracy and reliability of the sampling process?
This graph is the grail — the foundation itself…”
You forgot the fact that Mauna Loa is an ACTIVE volcano emitting CO2 so like the temperature measurements it has to be “adjusted”
http://sci.tech-archive.net/Archive/sci.electronics.design/2009-02/msg00386.html
Hey everybody!, climate changers found another scaring menace:
http://news.yahoo.com/s/mcclatchy/20100307/sc_mcclatchy/3444187
They are looking for a way out, however this too is a lie as PDO being negative (lower sea temperatures) increases oxygen solubility in sea water.
Another Ban kee moon science-global government marketing.
Man is not creating C02. He is releasing it from storage by the burning of hydrocarbons made by the biosphere and stored by geology. There’s a big difference between the two.
This post is misguided on several levels. First, it assumes that the effect of CO2 is saturated over the whole frequency spectrum, which it is not. Some parts of the IR spectrum are indeed saturated, and CO2 increase won’t have any effect. But in other regions of the spectrum, and particularly at the poles, the edges of the CO2 bands are anything but saturated.
If you think of the atmosphere as a blanket with holes in it, you don’t get much improvement in the blanket by stretching a thin film over the intact part, but you do improve by covering the holes.
Second, it’s simply silly to say that the earth came close to catastrophe by going below the threshold for plant growth. What pulls CO2 out of the atmosphere is largely plant growth. It’s self limiting; as CO2 levels drop, plants grow less, and that limits further decrease in CO2.
If no experiments have been performed, would it be possible to create containers with exactly the same atmospheres in them but then add extra levels of ppm of C02 and/or other trace gasses to certain containers and then observe what happened naturally to the temperatures of each container over time ?>>
Try
http://www.john-daly.com/artifact.htm
Simulated earth atmosphere with 2.6% water vapor and two different levels of CO2 (one double the other) and measured absorption of LW being transmitted through it. Concluded IPCC estimates were high by 80X. However, my assumption is that this was done at room temp. Other temperature ranges and other water vapor concentrations would give different results. Earth is inconveniently round, spinning, and has the atmosphere on the outside as opposed to a cylinder with atmosphere on the inside.
John Finn…your application of “appeal to authority” is humorous, entirely fallacious from a logical pov, but definitely humorous.
It is feeblemindling groping in the dark, trying to guess phantoms by empty discourse, if temperatures will scorch us or not, and what causes what is it what we call it temperature.
J.C.Maxwell put it this way:
“…when, however, there is a general transference of particles in one direction, they must pass from one molecule to another, and, in doing so, may experience resistance, so as to waste electrical energy and generate heat”
“On physical lines of force” , by J.C.Maxwell.
In reply to Mike,
Yes, AGW skeptics say that the climate is too complex for all of the models to properly account for all of the variables and how they interact. That is a true statement.
However, it is still possible to show with some very simple mathematical exercises that their assumptions are probably outlandish.
The two statements are not incompatible with each other.
Hi could someone tell me where I can find what the total Infra red energy coming to the Earth from outer space, which is of the frequency which can be absorbed or radiated back to earth or reflected back to space by co2?
These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.
Now that is funny…and sad. Difference between an engineer who has to make something work and an academic that merely has to satisfy his “customers” desire for results in a certain form. What if we added a little feedback into the funding cycle? Observable predictions result in more money, missed or unexplained observations result in less money? Would that have runaway negative feedback?
Larry – Interesting comment. I’ve always thought there was something strange about things were framed in terms of forcings, feedbacks, positives, negatives, fasts and slows. Perhaps someone was trying to avoid the simpler but peculiar sounding formulation…. warming is going to cause warming. What I’d like to say is that warming causes more humidity and more humidity will cause more frequent rains and more rain presupposes more clouds and even the IPCC admits that the effects of clouds on climate are poorly understood. Ergo, dire predictions are less than plausible and certainly uncertain.
Larry,
You are correct. A system which had a never-ending positive feedback loop would essentially self-destruct. Most sane people realize that the climate of the earth is not such a system. It is known that the warming effect of CO2 is logarithmic and not terribly significant, and it is now postulated that water-vapor feedback is actually negative rather than positive, so the climate seems to have a thermostat, so to speak.
Mike M (06:46:15) :
“As most plants receive more CO2 than the present day concentration they grow faster and fatter. In order to do that they must be absorbing solar radiation and converting it into potential chemical energy, (fats and sugars, etc.), at a faster rate. Such conversion by photosynthesis could be represented as ‘lost heat’ in the earth radiation budget in that radiation that arrives at the surface then ‘disappears’ from the equation.”
Yes, photosynthesis is strongly endothermic and increasing concentration of CO2 increases photosynthesis, so more cooling. Transpiration is important (latent heat of evaporation) but decreases somewhat with increasing CO2 as stomata close up. The plant canopy couples its cooling to the surrounding air by conduction, so to all air molecules, not just the tiny CO2 component.
Everyone knows that it’s cooler on a grass lawn than a concrete or asphalt yard. Some buildings deliberately grow grass on their roofs for their cooling effect.
Of course, all this endotherm becomes exotherm when the vegetation is burned and it reverts again to CO2 and water.
If people want carbon capture and storage, with cooling to boot, they could simply plant fast-growing trees, cut them down after 30 years and store the remains (including as the structure in permanent buildings). Much simpler than trying to do it on a coal-fired power plant.
David, To me an illuminating additional graph would show the theoretical cumulative radiative forcing of H2O and CO2 based on the assumption that incremental CO2 forces additional atmospheric H2O ie a stacked version of your last graph above (but ignoring other H2O feedback effects such as cloud effects and latent heat of evaporation etc) and ranging from 20 to 400ppm CO2 and beyond. I assume the forcing effects of CO2 and H2O are individually logarithmic with the H2O part being larger. Such a graph would show the effective baseline around which the other feedbacks are hypothesised to force reality. Of course my request assumes we know the pre-industrial level of H2O in the atmosphere and it’s relationship to temperature.
Isn’t it interesting?
We have to have HUNDREDS of temperature surface stations all over the world (whether they are accurate or not is another story)
We seem to rely on TWO tiny samples of trees – the famous bristlecones and the Yamal set, from two small geographic areas
We have ONE definitive measure of CO2 from Mauna Loa – even though atmospheric CO2 doesn’t seem to be evenly distributed around the world.
What’s the rationale for the various sample (or sampling) sizes? Am I missing something?
rob (04:00:46) :
… Over the past 140 years the British weather observatory situated in the Himalayas revealed a temperature drop of .4 degrees.
Think about it. This is the data you can trust. When a meteorological station is located far from urban environment and volcanic activity, when people recording the measurements are not financially interested in altering them, and when they don’t pick the lowest temperature dip as a starting point for comparison, suddenly there is no “global warming” and never was.
For this reason, and for many other equally important reasons, the United Nations should be boycotted and abolished. It is a criminal organization that causes enormous harm to freedom, culture, and civilization.
it was established before AGW ideology that c02 bandwidths are fixed at between 7 and 8% of outgoing atmospheric energy. Outgoing atmospheric energy is anything from 1-5% of the radiation budget (mainly from soils) that makes itself available to c02. Measured as temperature c02 capture is 0.15C, certainly not 3C.
only the stefan boltzmann equation could increase this 8% budget artifically to an absurdly higher figure to give 3-5C in the near future (the basis on which the calculation was made due to anthropogenic c02 emissions)
in fact there are many poorly applied equations used to contrive and exagerrate the greenhouse effect in order to increase the alarm and produce a hypothetical future 3-5C increase based on anthropogenic emissions. true,, deserts could give off more radiation- 10%, but matter at 15C, which is quite cool, thermalises so as not to radiate beyond 1% of its energy, besides which at those temperatures, IR radiation bypasses c02 – especially desert regions
Shade (08:15:35)
The temperature difference is explained by air pressure and the ideal gas law in a closed system. The atmosphere isn’t a closed system – The experiment would have to be 350ppm in a vessel and 450ppm in a larger vessel to create the same pressure. Then the experiment ( as tried by Anstrom) would reveal fairly objective results. The external heat source would have to correspond to earth temperatures between -40C and 45C
Ken Roberts (07:41:04) :
“As I understand the process at the primary sampling station for CO2 at Mauna Loa, a sampling tube is purged with inert gas and then a sample of air is drawn.
This sample is measured spectrographically and the daily results are added; has anyone ever established that the purging is fool-proof?
Has any study ever investigated the accuracy and reliability of the sampling process?”
Mauna Loa is the world’s largest volcano, and a very active one. Ever heard of how many gigatons of CO2 volcanoes put out?
Mauna Loa used to have pineapple plantations on its slopes near the laboratory, but these have dwindled away since the 1950s. Anyone know that pineapple plants, using the unusual CAM photosynthesis pathway, are among the world’s most efficient sequesterers of atmospheric CO2? The increase in ambient CO2 when removing pineapple plantations is well established.
Mauna Loa must be one of the worst places on earth to establish a benchmark for CO2 measurements. Unless you had a particular agenda, of course.
Funny that.
The very premise of this article that 30C increase in surface temperature is explained by greenhous effect is wrong. This difference is due to convection. It is the difference between surface temperature (+14C) and the temperature at lower boundary of stratosphere (-18C), since there is no convection above this altitude. But atmospheric convection is adiabatic: the same body of air ascending to, say, 10 km, will expand due pressure drop and so get cooler without loss of its heat content. This adiabatic cooling has nothing to do with trapping of infrared radiation, this is simply laws of gas expansion. What the Wood’s experiment really shown is that greenhouse effect does not operate in real greenhouses, the only heating is due to suppressing of convection. Does it operate in real atmosphere? Probably, yes, but trapping of heat will only enhance convection and so enhance convective cooling. No real experiment with real atmosphere is possible, but some observations indicate that the main heat-trapping gas is water vapour: day-to-night temperature difference is much higher in deserts, where air humidity is near zero, than in wet regions. During night convection is weak or absent, and most cooling is radiation cooling, and it seems, the only difference is water vapour content. CO2 does not enter into this effect, and its contribution is not known and can be immesurably small.
Henry Pool (07:59:34) :
It absorbs radiation at 13.7-16.3 microns with a peak of 15 microns – yet radiation on average leaves earth at 10 microns, which equates with 15C, or 288K. 15 microns equates with subzero temperatures that can be found at the poles – so heat capture of c02 in the atmosphere is a rather rare event, and is fixed at around 6-8% of atmospheric thermal energy, achieved by the 1st 100ppm where its absorbtion window closes – well outside of normal temperatures. Its true that a c02 molecule’s stretching mode would allow it to transfer energy to other atmospheric molecules, such as the ghg water vapour, but this requires so much energy that it doesn’t occur even at 300K, with the c02 absorbtion bands, and there’s some 3,000 other mlecules apart from c02 in a given volume of air, making collisions between thermally excited c02 molecules very unlikely. Molecules of like kind are more efficient at transferring energy to one another. In the absence of such, thermal degradation takes place very quickly. (a billionth of a second), so vibrationally excited c02 thermalises very quickly with oxygen and nitrogen
Ira (07:58:20) Thanks, Ira, that’s an excellent explanation of how this works. That, and the complete disconnect between historical CO2 and temperature (http://ff.org/centers/csspp/library/co2weekly/2005-08-18/dioxide.htm ) make it very difficult for me to believe in AGW.
also:
Richard111 (04:42:57) :
“As a non-scientist, can anyone please explain why there is no convective heating
of the atmosphere? Are thermals due entirely to CO2 in the deserts?”
Richard, I fly small airplanes in the desert, and CO2 has nothing to do with thermals. You get thermals that make you tighten your seat belts because there are few clouds. The sun differentailly heats the ground depending on local albedo. e.g. black highways are hotter than vegetation. This sets up convective cells. Air rises over the hot spots on the ground and settles over the cooler ground spots. Makes bumpy air.
In places like Florida, where there is a lot of humidity, clouds form where the updrafts take the water up to the altitude at which the water vapor turns to liquid droplets.
Sorry about the OT digression.
And I like this paper, which says that CO2 concentrations have been as high as 480ppm in the 1940s. Figures, derived through chemical gas analysis.
http://www.friendsofscience.org/assets/files/documents/CO2%20Gas%20Analysis-Ernst-Georg%20Beck.pdf
Any problems with this paper too?
.
One problem with these simple experiments is the climate system is not simple at all.
Richard Telford (01:00:29) : “I don’t know if this post was supposed to be misleading and confusing but is certainly is.”
Obviously, at least one person has been misled and confused. This is a good thread and perhaps based on reader comment the post can be supplemented with additional material that will lessen Mr. Telford’s confusion. Dismissing his comments out-of-hand is neither productive or polite. Clarification seems warranted.
Not a good experiment, IMO. There are escape paths for internal heat other than back through the window, and the Earth isn’t accurately modelable as a small, fully-enclosed greenhouse lined with black cardboard.
Oh, and he’s using sunlight already filtered by the atmosphere as input. But that’s probably just a quibble.
Is the Sun going back to sleep? It tried to get out of bed for a little and has been dragging it’s ass with just a few sun specks. Take a look, the sunspot number is zero again.
Solar wind
speed: 325.8 km/sec
Sunspot number: 0
Updated 07 Mar 2010
Spotless Days
Current Stretch: 2 days
2010 total: 3 days (5%)
2009 total: 260 days (71%)
Since 2004: 773 days
Typical Solar Min: 485 days
http://www.spaceweather.com/
Larry (08:18:31) :
“Any computer model with a little bit of excess positive feedback is going to predict whatever it is modelling is going to hell in a handcart over sufficient iterations. These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.”
Generally, positive feedback is a very bad thing as it causes instability and oscillation. Biological systems have strong negative feedbacks otherwise life would have died out long ago.
A small amount of positive feedback can sometimes be accommodated but there is then need for ‘intelligent’ control, monitoring and possible intervention to ensure that a runaway problem doesn’t develop. We run incandescent lightbulbs from voltage sources, relying on a NEGATIVE feedback mechanism – as the filament heats, its resistance increases, reducing the current and so throttling back on the I^2R heating losses. Equilibrium is quickly established, and the system is intrinsically stable even if one varies the voltage. Not so with driving an incandescent lightbulb with a current source where the system then has POSITIVE feedback: as the filament heats its resistance increases so I^2R heating losses increase, so it gets hotter, so its resistance increases more, so I^2R losses increase even more. Even with this regeneration, there will be a low value of current at which (a not-very-stable) equilibrium will be attained. However, there is a critical current above which the system becomes unstable and thermal runaway ensues until the filament blows. Depending on thermal inertias, a small glitch that takes the current momentarily over the critical current can prove fatal to the system by pushing it into a region of instability from which there is no recovery (without external intervention). So, as a designer, you would never knowingly run a filament lamp from a current source. As a designer, you wouldn’t design a biosphere with positive feedbacks either if you wanted it to be stable.
As Richard Lindzen has remarked, any significant positive feedback in the climate system is a problem for the theist because it would be evidence of ‘UnIntelligent Design’. That’s not compelling for the atheist, but even there one could consider the argument that of all possible earths that could exist, the only ones that can persist are those that don’t exhibit positive feedbacks. Since this earth exists with a flourishing biosphere and has without doubt persisted for a very long time, then this evidence would tend to militate against the presence of positive feedbacks as well. Of course, these are metaphysical arguments, but when someone propounds a crazy idea like AGW it’s worth doing a reality check by taking a look outside the box.
One feedback which has not been discussed here (unless I have missed a comment) is the presumed increase of outgoing CO2 from the soil when climate is getting warmer. During this winter there was a study where the authors claimed to have quantified this effect: for each degree oC there would be 7 % extra warming because of extra release of CO2. According to climate models a standard value for this feedback has been fixed to 40 % extra warming. The difference would be 1.07 oC contra 1.40 oC.
Thus we have in fact two uncertain factors in IPCC models, this outgoing CO2 and the clouds.
I wonder if Hans Erren could comment on this.
Larry Huldén
Finnish Museum of Natural History
Richard Telford (04:39:45) :
The natural CO2 forcing is shown without any feedbacks, whereas the anthropogenic forcing is shown with feedbacks. This is misleading. Nobody would argue that the natural changes in CO2 are not magnified by feedbacks (try to explain the glaciations without feedbacks) One can argue about the magnitude of the feedbacks. Perhaps the IPCC has them too high. Perhaps too low.
Well…actually we would. Not only the absolute value of the “magnification” of feedbacks, but the direction. As for your glaciation analogy, lookup orbital cycles. See if that helps your understanding.
Hi JonesII
Thanks for the ‘Magnetic drain’ link.
Here is a graph showing huge drop in the intensity of the Earth’s GeoMagnetic Field (GMF, vertical component) at latitude of 36 degrees South.
http://www.vukcevic.talktalk.net/LFC13.htm
Location east of Concepcion (in the Andes near the Argentinean border) the GMF has one of the largest drops anywhere on Earth (in 1600 was 54 microTesla , in 2010 is 14.6 microTesla ) i.e. in 1600 GMF was 370% stronger than it is today.
You can find the South Atlantic GMF sweep on: http://www.vukcevic.talktalk.net/GandF.htm
Congrats David. That is an excellent, clear and easy to understand exposition, and illustrates beautifully the nonsense of water vapor positive feedback. I did a check of all the NH high latitude temp. stations a couple of years ago, and the 1976 PDO shift shows up very clearly, especially for Alaska and Siberia. In greenland it gets obscured to some degree by NAO shifts. For Alaska, if you factor out other impacts, like paved runways in the ’90s, and UHI increases you also have the “no further warming”.
Clearly, the process is:
– hypothesize warming
– build a model to prove warming
– tune the model so it gives the desired warming
– invent a mechanism that explains the fudge factor used to tune the model
WV positive feedback is the mechanism for post 2000 warming.
The fudge factors to make the models backcast are also interesting. Very slow mixing between the surface and deeper layers of the ocean are necessary to give the needed CO2 pulse lifetime and then the cooling from ca 1945 to 1975 is aerosols. Noone explains the source of the aerosols, nor why they ceased to be effective after 1975. With 2 undemonstrated mechanisms you can make the models backcast pretty well, and then with a third one you can get a “catastrophic” (also undemonstrated) forecast.
Ain’t AGW wonderful??
If you want to see an excellent performance by sceptics and a disaster by alarmists you would find this difficult to beat.
A must see.
Readfearn – What a plonker.
See Tony Brown’s excellent post at The Air Vent:
“Historic variations in CO2 measurements.”
http://noconsensus.wordpress.com/2010/03/06/historic-variations-in-co2-measurements/
Larry (08:18:31) :
(…)
These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.
————-
Reply:
You’re absolutely right Larry. And without going into a whole lot of theoretical or graphical persuasion, what you say is obvious. Why? From a geologist’s standpoint, if there was truly a “tipping point”, the earth would have tipped a long time ago when the CO2 levels were many times what they are today. Yet we don’t see the oceans boiled up into the sky in a soup so thick you could cut it with a knife. And those that propose “global warming” as the cause of earth’s 5 major extinction episodes rather than catastrophic impacts are simply ignoring the obvious.
Before those proposing a “tipping point” gain any credibility whatsoever, they need to propose an “untipping point”. Please identify the mechanism. Barring that, it’s all pretty much fantasy. I simply grab a photo of the earth taken from space as Exhibit A. And I’m pretty certain that’s how the earth appeared before the industrialized era began 150 years ago.
mathman (08:32:29) :
“Is anyone out there thinking?
CO2 is a gas found in the atmosphere. As is true of many molecules, CO2 responds to certain incoming radiation (photons) by jumping to an excited state. I am citing the obvious here. What then? Does the CO2 remain excited forever? No. The excited state decays back to an unexcited state, releasing the quantum of energy (this time without regard to direction).”
Hey, hang on: I’m getting uncomfortable with some of the comments here. CO2 is a MOLECULE like water is a molecule. Molecules can be excited into resonance in a way that atoms can’t. Nils Bohr was right about atoms, for example sodium absorption and emission spectra, but molecules are different: they can have resonances between the atoms that atoms themselves can’t have. When you put your food in the microwave oven the frequency of the magnetron is tuned to excite a molecular resonance for water, not an atomic one: the non-ionizing radiation is not exciting electrons into different states in the individual atoms. Air is made up of O2, N2, CO2 and CO2 molecules, and Ar atoms.
In the IR spectrum of emission from the earth’s surface, the only atmospheric absorption that takes place worth considering are molecular absorption mechanisms, as the atomic absorption/emission lines are way out of the spectrum. If that’s the case then what Nils Bohr said was not relevant to this case as we are talking about a different mechanism – molecular resonance, not quantum mechanics.
Vukcevic (10:22:58) Thanks Vuk! Really surprising, and as the line of force goes from the strongest to the lowest…there is a “pressure” on the spot.
“Mike (04:54:41) :
Let’s see, usually we are told by AGW skeptics that the atmosphere is too complex to understand.”
This relates to the chaotic nature of the climate. Within Newtonian mechanics the famous 3 body problem is chaotic and the paths of the individual bodies cannot be calculated exactly because of the uncertainty of the exact initial conditions. But it is known that the maximum possible distance between any 2 bodies will be determined by the balance between kinetic and gravitational potential energy.
Similarly the climate is governed overall by an energy balance but the predicted configuration of the atmosphere is unpredictable. Hence we know the earth can’t get warmer than the sun as an extreme example but we can’t predict how winds and ocean patterns would change.
Should have read “Air is made up of O2, N2, CO2 and H20 molecules, and Ar atoms”
Jaye (09:10:13) :
John Finn…your application of “appeal to authority” is humorous, entirely fallacious from a logical pov, but definitely humorous.
Whereas you appear prepared to believe any old rubbish as long as it supports your fervent wish that CO2 should have no effect. Well, suit yourself, but when you find that AGWers are able to ridicule sceptic arguments don’t start whining.
Any computer model with a little bit of excess positive feedback is going to predict whatever it is modelling is going to hell in a handcart over sufficient iterations. These modellers should be made to repeat before they go to work “any natural system that had unrestrained positive feedback would have destroyed itself before I got to model it”.
Which is why I believe they do not show their results for farther than 100 years out. Not that the results would be useful, but they would show if the models are stable.
Funny thing is that you don’t hear much about tipping points from the climate “scientists” these days although it was all the rage for a while. Perhaps they were afraid some one would tumble to the fact that the models are broken Fundamentally.
Murray (10:27:29) :
Very slow mixing between the surface and deeper layers of the ocean are necessary to give the needed CO2 pulse lifetime and then the cooling from ca 1945 to 1975 is aerosols. Noone explains the source of the aerosols, nor why they ceased to be effective after 1975.
Couldn’t have anything to do with a world war and over 500 atmospheric nuclear bomb tests could it!
Can Mr. Archibald please include some citations? I have no trouble believing that the IPCC models assume that water vapor feedback effects start at 280ppm. They do much worse. For instance, they parameterize total solar effects as having 1/14th the forcing effect of CO2, when numerous studies show a .6-.8 degree of correlation between solar activity and past temperature change.
Want to see where solar effects are assumed (not found) to be tiny compared to CO2? Look on figure 2.4 on page 39 of the Synthesis Report: http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf
The only solar variable included is TSI, which is accorded a forcing of .12 W/M2, compared to 1.66 for CO2.
Providing the citation allows other people to USE the information because they can back it up. Similarly, we need the citation in order to use Mr. Archibald’s information. He is making a pretty important claim. It would be nice to be able to verify and cite it.
What percentage of the CO2 increase can be ascribed to our increasing use of fermented beverages? More people = more booze drinkers; is this a significant part of the CO2 problem?
Well I for one have a problem with the entire premise of this essay. For a start “Climate Senistivity” is defined as the permanent increase in the mean global surface temperature of the earth for a doubling of the CO2 abundance in the atmosphere. I googled dozens of papers; in fact dozens of pages of papers which citre this definition or the equivalenty in slightly different words. The IPCC evidently even gives a value for it namely 3.0 deg C per doubling. Well actually to be more accurate they say 3.0 +/-1.5 deg C, a 3:1 spread in value. I don’t know whether that is a GCM modelled value, or an actual planet earth observed value.
In any case they have a Temperature versus log CO2 relationship; that’s not the same thing as a “Forcing” in Watts per metre squared versus log CO2.
Now your curves look very pretty, especially that first one, the modtrans logarithmic plot.
Now toss in a 3:! spread about that nice curve, and then try to convince me that the relationship is still logarithmic; well more likely to be logarithmic than say linear.
Well the relationship between mean global surface temperature and “Forcing” in Watts per m^2, is not even linear. Well the simplest assumption that the connection exactly follows black body radiation laws, would make the “forcing” go as the 4th power of the absolute temperature. Luckily, if the relationship was logarithmic, that 4th power merely changes the scale.
Unfortunately the thermal processes that remove heat from the earth are a lot more complex than simply black body radiation; and the rate of heat loss globally is not simply related to the mean surface temperature.
But the proof of the pudding is in the climate data over a longer period of time. Your pre-inductrial levels of CO2 to today, are not even one half of one octave of doubling, so to twice today, is less than 1 1/2 doublings.
Hoe about five doublings; well halvings anyway, that have taken place over the last 600 million years.
See http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif
Now there you have CO2 dropping from 7000 ppm (25 times today’s value) down to your 180 ppm low. Yet over most of that 600 million years, the temperature remained constant at 22 deg C.
So currently, the earth is in an anomalous cold phase, the likes of which we haven’t seen in over 300 million years; well maybe 260.
It would be nice if somebody was able to show us some believable observational data, either measured or believable proxy data, covering at least one octave of CO2 doubling, which confirms a logarithmic relationship as more likely than a simple straight line linear relation.
It would be even nicer if someone would offer even a simple physics model for why the earth’s mean surface temperature should be expected to vary as the logarithm of the atmospheric CO2. Ther’s no such physical connection that I am aware of; so I’d like someone to point to such a theory.
Well a lot of people like to point to Beer’s Law, which governs the transmission of light through absorptive media; optical glasses for example.
The net transmission decays exponentially with thickness of the (assumed homogeneous) absorbing medium. The concept is simple; the probability of absorption of any single photon is a constant for a particular wavelength and thickness of the sample, and of course on the nature of the material. The probability of the photon passing through many such layers is simply the product of the (transmission) probablilities of all those layers.
Well Beer’s law works quite well, if you measure the transmitted energy with a monochromator. Some “fast cut” long pass color filter glasses can easily reduce the transmission to 0. 001 % in say 3 mm of glass, just a few hundred nanometres longer in wavelength than the wavelength which passes 50% (the cut-off wavelength for that sample.
But don’t expect to get only 0.001% of the energy transmitted through that same sample. Replace the monochromator with a wide bandwidth detector, and you will find orders of magnitude more energy than the absorption curves claim. The problem is that such materials fluoresce, and the energy absorbed by the glass at one wavelength is then re-emitted at a longer wavelength, and emerges out the other side simply shifted to a longer wavelenght. You can stack up a whole series of such glasses with increasing cut-off wavelengths, and each will sequentially shift the wavelength so that it passes through the next layer too. So Beers law is NOT always followed, in the case where the energy can be re-emitted at longer wavelengths.
The best one can hope for in say visible light absorption filtering, is that the visible wavelength energy that is absorbed by the filter results in heating, and the final emission is in the LWIR spectrum; hopefully a long way away from an area that can influence whatever system the filter is part of.
Well guess what happens in the atmosphere when GHG molecules e.g. CO2 absorb specific photon energies in the 13.5 to 16.5 micron range. That energy becomes thermalized, and transmitted to the ordinary atmospheric gas molecules; which eventually radiate a thermal continuum LWIR spectrum, based on the temperature of the atmopshere; not the temperature of the original emitting surface.
There’s no evidence that such processes conform to Beer’s Law, or in any other way exhibit a logarithmic response as to the resulting mean earth surface temperature rise.
Al Gores famous graphs in his book, of ice core temperatures and CO2 both have the same general shape, as he makes clear in his book, and apparently did so in his movie as he waved them in front of the audience, and suggested that they awere the same. If one was the logarithm of the other they certainly wouldn’t look the same.
The 600 million years of proxy data cited above certainly do not support a logarithmic connection between either mean global surface temperature, or “Forcings” and CO2 abundance in the atmosphere.
Earth’s comfort temperature range, is being controlled by something a whole lot more influential than atmospheric CO2.
For one thing, over the earth’s extreme total temperature range from -90 C, to over +60 C (all of which could be co-existing simultaneously); the maximum possible surface emittance bounded by black body radiation laws, covers a 11 to one range of Watts per square meter (“forcings” if you like). That sets the maximum energy available to be captured by CO2, depending on location on earth. There isn’t any global network that is sampling the value of “Climate sensitivity” all over the earth to arrive at the IPCC’s 3.0 +/-1.5 deg C per doubling of CO2.
And the definition says nothing about CO2 getting any assistance or support from any other GHG; that is the result of doubling CO2; period. Other GHGs each have their own effect and they are unrelated to how much CO2 is present.
To me, the whole idea of “Climate senitivity” and a logarithmic relationship between mean global surface temperature and the log of CO2 abundance in the atmosphere simply doesn’t hold water, either experimentally or theoretically.
But that is just my opinion of course; I’d be happy to learn of either a theory or measured data showing otherwise.
Alan D McIntire (07:56:20) :… OBVIOUSLY the feedbacks must be mostly negative, probably due to clouds,…
Well, if the geologic record of earth’s temperature is correct then temperature definitely hits some sort of a severe negative feedback ‘wall’ around +22C. It’s as though we have a giant air conditioner out there with its thermostat set at +22C.
http://geocraft.com/WVFossils/PageMill_Images/image277.gif (According to Al Gore earth should have burnt up 500-600 MYA when there was at least 3000 PPM CO2.)
If not because of water vapor then what else could it possibly be? We already know that warming happens the least in the tropics and most at the poles so the key to the negative feedback from water vapor appears to be found in whatever is happening in the tropics – IMO large quantities of water vapor’s latent heat being convected way up there above most of the GHG’s. As the earth gets warmer – tropical conditions would expand to higher latitudes thus enhancing the negative feedback over a larger area.
Ralph (10:04:17) :
And I like this paper, which says that CO2 concentrations have been as high as 480ppm in the 1940s. Figures, derived through chemical gas analysis.
http://www.friendsofscience.org/assets/files/documents/CO2%20Gas%20Analysis-Ernst-Georg%20Beck.pdf
Any problems with this paper too?
There’s a lot wrong with it. The measurements are clearly taken at locations which are contaminated by local effects. There are plenty of places where you can measure 500 ppm but they do not provide a global representation of CO2 in the atmosphere, i.e. CO2 is not “well-mixed” in the atmosphere. The Beck numbers make no sense whatsoever. According to Beck, there is an increase of around 150 ppm between 1930 and 1940. Where did that lot come from? Modern fossil fuel emissions are about 7.5Gt Carbon per year which corresponds to ~3.5ppm. Around half of that is absorbed by natural sinks in the ocean and the terrestrial biosphere (there was a post on WUWT about this a bit back). This gives us an average increase of just under 2ppm per year. What do you imagine caused the 150ppm increase?
It gets worse. According to Beck there is a similar rise in the 1820s. There are also annual increases (and decreases) of 50 ppm in a single year. How this paper is being treated seriously by anyone is beyond me.
I think everyone agrees that the direct effect of doubling CO2 is less than 1.5C. The area of disagreement has more to do with feedbacks in the climate models.
Ralph (10:04:17) :
Any problems with this paper too?
I don’t see how there can be, they are actual measured values, not guesses from Ice cores, Tree Rings, Leaves etc.
But the IPCC & Climate Scientists seem to want to ignore written History, because it is Inconvenient.
Just look at Australia’s history compared to current “Unprecedented” temperatures, droughts & Rainfall etc. They just love to apply that “Unprecedented” when it is obviously not so.
Gerard Harbison (09:06:07) :
Some parts of the IR spectrum are indeed saturated, and CO2 increase won’t have any effect. But in other regions of the spectrum, and particularly at the poles, the edges of the CO2 bands are anything but saturated.
And the net result of predicted strongest increase of greenhouse effect is..
Antarctic – cooling?
http://climexp.knmi.nl/data/itlt_0-360E_-66–90N_na.png
Arctic – AMO oscillation?
http://climexp.knmi.nl/data/icrutem3_hadsst2_0-360E_66-90N_na.png
Where is the strengthened greenhouse effect fingerprint, when the most sensitive areas on the Earth show nothing or just regular variations, well correlated with oceanic oscillations?
Well, how have the IPCC done so far?
http://www.ianschumacher.com/img/TempsvsIPCCModelsWM.jpg
http://deepclimate.files.wordpress.com/2009/05/ar4-a1b-a2.gif
http://joannenova.com.au//globalwarming/graphs/akasofu/akasofu_graph_little_ice-age.gif
And here is Prof Jones admitting the lack of statistically significant warming since 1995.
http://news.bbc.co.uk/2/hi/science/nature/8511670.stm
So rising CO2 since the start of the industrial era means we should be cooking under the positive feedback which we are not. Its
“The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t,”
http://www.eastangliaemails.com/emails.php?eid=1048
Help me understand the multiplier.
If adding CO2 means more water vapor and accordingly more greenhouse from the water vapor, then this will, in turn create more heating, water vapor and yet more heating. This appears to be a classic system with positive feedback which would limit at some value unrelated to the initial CO2 increase.
What keeps this from happening in their models?
David,
As this paper is a pretty fundamental & concrete analysis of the potential effects of CO2, could you please provide references for the various facts at the front end of the paper – such as GHG’s providing 30 deg C or warming, CO2 being 10%, etc – It is important to have those for all to see for independent verification – as all analysis flows from those assumptions. Just setting high standards for work presented here to help improve the case being made & show that skeptics are scientists with the highest & most transparent of standards
John Finn (10:59:36) :
Jaye (09:10:13) :
John Finn…your application of “appeal to authority” is humorous, entirely fallacious from a logical pov, but definitely humorous.
Whereas you appear prepared to believe any old rubbish as long as it supports your fervent wish that CO2 should have no effect. Well, suit yourself, but when you find that AGWers are able to ridicule sceptic arguments don’t start whining.
I don’t believe I exposed any of my beliefs in pointing your transparent attempt at “appeal to authority”.
The issues are much deeper than a silly jihad between “Warmers” and “Skeptics”. The travails of “Steady State” vs ‘The Big Bang” crowd (fyi, the name Big Bang was an insult just as denier is used today) is an interesting study in scientific jihad. One thing I do know, models and simulation are only tools that can, at best, aid in understanding. The results of M&S are only truly useful if they have gone through IV&V and that they can predict new things. Ultimately, empiricism has to rule the day.
If the GHG effect of CO2 is logarithmic, then so is it for HOH, yes? If so, then we are so “far-out” on the curve that any type of “water vapor feedback” is not possible. No?
In ordinary Optical absorption theory, a basic assumption is that an incident photon has a certain probablilty of being captured in passage therough some small thickness of material. To particle physicists, this is a simple concept, where a given potentially absorbing atom/molecule is considered to lie at the center of a target area; its “Capture crossection”, and the assumption is that if the appropriate particle (including a photon) strikes that target area, then the contemplated reaction occurs. Well of course it is a statistical probability so there isn’t really a go/no-go decision made if the target is hit or missed. The Units of “Crossection” are typically “Barns”, yes as in can you hit the broad side of a barn. One barn is 10^-24 square cm, so one might argue that is is one picon square; which makes a pecon pie among the world’s smallest.
In a typical solid, the molecular/atomic density is so high, that a capture crossection would have to be very small to have so many target areas overlapping in a thin section, that a photon was bound to hit something eventually.
In the case of non-fluorescent solids, and say visible light spectrum wavelengths, crossections can be sub-atomic dimensions. For nuclesr reactions they are even smaller, since the incoming particle has to interract with the nucleus, rather than with the surrounding electron cloud, in atomic of molecular capture events.
The result of optical absorption in non-fluorescing materials, is that the captured energy, ultimately appears in the form of heat; thermal agitation of the atom or molecule, that is communicated to surrounding , molecules.
The quantum physicists might refer to such events as “phonon” interractions; a phonon being a quantum of accoustic energy; aka thermal vibration or “heat”.
Solids can have significant “specific heats”, so the temperature rise caused by a photon capture can be extremely small. As a result the increase in BB like thermal radiation from a solid optical medium absorbing photons, might be too small to easily detect.
In any case, the result of the overlapping of crossection targets, is that the transmission, (tau) = exp(-alpha.x) where x is the distance travelled, and alpha is the absorption coefficient.
This is essentially Beers Law, or sometimes referred to as the Beer-Lambert Law.
In a liquid such as say ocean (sea) water , alpha has values as low as 10^-4 cm^-1 at the lowest which is about 470 nm in the blue region. Over the near UV (300 nm) to near IR range (800 nm) , alpha is always less than 0.01, so the light decays to 1/e (37%) in about one metre.
Sea water is most absorptive at 3.0 microns where alpha has a value of about 9,000 cm^-1, so you get 1/3 transmission after only about 1.1 microns of distance. Over most of the IR range longer than 2.5 microns, alpha is about 1000 cm^-1, so you get 37% transmission after about 10 microns for most of that range except the 3 micron abyss.
The temperature rise situation is similar to solids, but you now have the convective effects of heating to siphon off heat to a greater body of water.
So now what about the effects in the atmosphere, where similar molecular absorptions can take place in IR active molecules such as CO2.
Well once again you get the same absorbed photon energy being thermalized by conduction to the ordinary atmospheric gases of N2 and O2; except at bery high altitudes, where the mean free path between collisions is long enough for spontaneous decay of the CO2 excited state to occur.
But now we have a somewhat differnt situation from the soid or liquid case.
The specific heats of gases are orders of magnitude lower than for liquids, and solids; so the result of that CO2 photon capture for an LWIR photon from the surface (or elsewhere) is a MUCH GREATER TEMPERATURE RISE; compared to that seen in solids or liquids.
The result it that the intensity of the increased LWIR continuum thermal radiation from the ordinary atmospheric gases, is much greater than occurs in solids, with there much higher specific heats.
But be careful here; although a given atmospheric region may have a greater temperature increse from LWIR absoirption, that very same low specific heat, means that, the radiation of the thermal emission from that gas region, also results in a greater temperature drop for that pice of gas.
So the atmosphere is a very poor “heat” source, in terms of how much thermal radiation it can emit, for a given resulting drop in gas temperature; compared to what happens when the solid ground, or the ocean surface emits LWIR tot eh atmosphere. The atmosphere is not a very stiff source of thermal radiation, because of the low molecular density. And yes when it does radiate, that emission is pretty much isotropis, so opnly about half of it returns towards the surface.
David Archibald (05:09:20) : Wrote
“There is no need to rehash the science. Real Climate attacked my graph back in October 2007 in a piece entitled “My model, used for deception”. http://www.realclimate.org/index.php/archives/2007/10/my-model-used-for-deception/
That was the seal of approval. Real Climate felt they could no longer ignore it, they had to try to counter it. Thanks guys. Without that sort of feedback, you don’t know how effective you are.”
While I do try to contribute something meaningful to this blog from time to time, I defer for the most part, to the better informed participants on this site for more in depth analysis of the topic.
I do however, understand and appreciate the value of clustersourcing the topic in order to flesh out the fact from the fiction. I know how effective this process is because there is virtually no vested interest on the part of the participants. We have a more altruistic motive for participation here. The betterment of everybody.
Smokey (07:45:44) :
It’s clear from your graphs that neither the lower troposphere temperature (LTT) nor the outgoing longwave radiation (OLR) have been doing anything spectacular for the past 30 years. On the other hand, and this is just an observation from my Mark III eyeball, there does seem to be something of an “inverted, lagged, correlation” between them.
If you invert your temperature graph and move it to the left a bit (about 8 months), it tracks fairly well with the radiation graph. Not a perfect match, and there are surely other things happening, but on the whole, (and pardon this phrasing) it’s “consistent with” the following sequence:
(1) Earth dumps more OLR; 8 months later, the LTT drops.
(2) Earth dumps less OLR; 8 months later, the LTT rises.
I have no idea how long it takes for the troposphere to “catch up” to what is (mostly) happening on the ground and oceans, but the response certainly can’t be instantaneous. Nevertheless, the “correlation” might be just an artifact of a short data set, or “whatever it is” that the UAH and RSS people do when processing raw satellite data. (I have some misgivings about that.)
/dr.bill
Larry, Jay, John Finn, RockyRoad, and others who have discussed positive and negative feedback mechanisms:
Is there anything logically wrong with the following AGW position?
1) There are natural negative feedback mechanisms to absorb CO2.
2) These negative feedbacks kept CO2 in check and/or reduced CO2 from previous extremes without causing a runaway hot earth (unchecked positive feedback).
3) The negative feedbacks are now being overwhelmed by man made emissions that are increasing CO2 dramatically faster than in the past.
E.g., something along the lines of what’s being said here:
http://climateprogress.org/2008/04/28/human-driven-co2-rise-14000-times-faster-than-nature-overwhelming-the-slow-negative-feedbacks/
son of mulder (10:51:06) :
This relates to the chaotic nature of the climate
God does not play dice. Chaos is a mind disorder.
meanwhile, back at the UEA ranch:
The Carbon Change Agent Programme
SAVE MONEY. MAKE MONEY. BECOME A CARBON CHAMPION. Specialist staff from the UEA’s Low Carbon Innovation Centre (LCIC) will be delivering a training programme to develop Carbon Change Agents in businesses and organisations across Norfolk.
http://www.uea.ac.uk/nbs/evolve/carbon
7 March: UK Tele: Richard Gray: Row over leaked climate emails may undermine reputation of science
The Royal Society of Chemistry (RSC) and the Royal Statistical Society (RSS) have both issued statements declaring that it is essential that scientific data and evidence compiled by researchers be made publicly available for scrutiny.
Their comments come after the Institute of Physics said that emails sent by Professor Phil Jones, head of the CRU, had broken “honourable scientific traditions” about disclosing raw data and methods…
Dr Don Keiller, deputy head of life sciences at Anglia Ruskin University, however, claims that Professor Jones and his colleagues conspired to withhold information in case it was used to criticise them.
He said: “What these emails reveal is a detailed and systematic conspiracy to prevent other scientists gaining access to CRU data sets. Such obstruction strikes at the very heart of the scientific method, that is the scrutiny and verification of data and results by one’s peers.”
Professor Darrel Ince, from the department of computer science at the Open University, added: “A number of climate scientists have refused to publish their computer programs; what I want to suggest is that this is both unscientific behaviour and, equally importantly ignores a major problem: that scientific software has got a poor reputation for error.”
http://www.telegraph.co.uk/earth/environment/climatechange/7385584/Row-over-leaked-climate-emails-may-undermine-reputation-of-science.html
when will ALL the data, raw and adjusted, plus methods, etc be released? surely it’s time to force complete disclosure.
Tipping points and how to overcome them:
We get everybody on earth to converge on one spot. The earth gets heavier at that spot and the tilt of the earth’s axis changes (we “tip” it the other way). All we need to do is figure out if we want more tilt or less tilt.
Let the modeling begin!
I was reading here ( http://www.aip.org/history/climate/simple.htm ) that viewing the atmosphere as a series of distinct layers as opposed to as a single “slab” increases the likelihood that adding more CO2 will cause more radiative absorption. If CO2 doesn’t “capture” the outgoing radiation in one layer, a higher layer might do so, and still “trap the heat”.
That seems logical on the surface, like having 50 blankets instead of one, but I’m not sure how many layers they would need to propose to make the curve fit the theory. And I can’t imagine a large increase in effect even if it were true. Since greenhouse theory depends on the troposphere being well-mixed, that means the troposphere layer number always has to be 1.
The layer suggestion might hold up better in the stratosphere, but I know next to nothing about the stratosphere. Can anyone enlighten me in this area?
LOL
8 March: USA Today: Al Gore’s climate groups unite as he sees ‘massive’ opposition
“There has been a very large, organized campaign to try to convince people that it (global warming) is not real, to try to convince people that they shouldn’t worry about it,” Gore said during an interview on the Norwegian talk show Skavlan to promote his newest book Our Choice: A Plan to Solve the Climate Crisis. Gore said:
In my country, the oil and coal companies spent $500 million last year just on television advertising just on these questions. There are now five anti-climate lobbyists on Capitol Hill in Washington for every member of the House and Senate. So it’s been a very massive, organized campaign.
To bolster their muscle, two groups that Gore founded in 2006 announced Friday that they are merging.
The union of the Washington-based Alliance for Climate Protection and the Nashville-based Climate Project will create, they said, “one of the largest non-profit educational and advocacy organizations in the world.”
The unified group, which will carry the Alliance’s name, will have branches in eight countries, more than 200 staffers in 30 U.S. offices and 3,000 volunteers in 55 countries.
Some of its funding comes from Gore, who won the 2007 Nobel Peace Prize for his warning about climate change. It gets 100% of the proceeds of both his new book — which uses recycled paper — as well as his 2006 best seller, An Inconvenient Truth.
http://content.usatoday.com/communities/greenhouse/post/2010/03/al-gores-climate-groups-unite-as-he-sees-massive-opposition/1
@ P Gosselin (02:19:05) : “I’ve read in literature somewhere that CO2 contributes to about 25% of the greenhouse effect, i.e. 7-8°C. Can you cite where the 10% value comes from?”
You ask a good question. A quick search came up with the following, although it is only 3.6% rather than 10…. Hope it helps.
TABLE 3.
Role of Atmospheric Greenhouse Gases
(man-made and natural) as a % of Relative
Contribution to the “Greenhouse Effect”
Based on concentrations (ppb) adjusted for heat retention characteristics
Water vapor 95.000%
Carbon Dioxide (CO2) 3.618%
Methane (CH4) 0.360%
Nitrous oxide (N2O) 0.950%
CFC’s (and other misc. gases) 0.072%
Total 100.000%
http://www.geocraft.com/WVFossils/greenhouse_data.html
Completely O/T but I couldn’t help noticing that the “rogue” Himalayan British weather observatory which has recorded global cooling is in Almora. “Return to Almora” is the name of R K Pachauri’s allegedly smutty first novel!
Alec Rawls (11:26:03) :
An easy source is Wikipedia for “greenhouse effect”.
Mari Warcwm (05:41:01) :
Thankyou very much.
Boris (05:36:48) :
Water is the dominant greenhouse gas so what is allocated to CO2 is the spectrum left over after water.
John Finn (11:36:30):
You are providing incorrect information.
You say that “the Beck numbers make no sense whatsoever.” Beck only collated and reported on the data provided by many internationally esteemed scientists, including Nobel laureates, who performed tens of thousands of CO2 measurements.
There were numerous scientists doing the work that Beck reported [all amateurs in those days, although a few did one-off contract work]. Being a scientist meant that your reputation was everything, unlike today, where corrupt degree holders scheme to finagle the system for grant money. If any scientist in the 1800’s was caught fudging data, he was finished.
The CO2 samples taken, typically between ≈1-3% accuracy, equate to about 4 – 12 ppm when measuring CO2 at 400 ppm. A one percent tolerance is very accurate, even by today’s automated standards, when measuring atmospheric CO2.
Beck reports on six of the locations where CO2 measurements were taken. The only populated location was Leige, a relatively small town in the 1800’s. The other samples were taken in very sparsely populated locations: an island in the Baltic sea, the Geissen weather station, the Baltic sea coast, a high mountain outside of Helsinki, the desolate Ayrshire coast in Scotland, and on fourteen extended ocean crossings on scientific expeditions, from Europe across the Atlantic, to the tropics, Australia, North and South America, the North and South Pacific ocean, Greenland, the Arctic, Spitzbergen, and Antarctica. No samples were taken in large cities or industrial areas.
Thus, the CO2 samples [along with other samples such as ocean pH – which turns out to be the same as today’s ocean pH] were the average readings taken from many unpopulated and very sparsely populated areas in both hemispheres, on mountains, on seashores and on mid-ocean crossings. Contrast those numerous, isolated locations with today’s main CO2 reporting source, located on the Haleakala volcano on Maui.
And the samples taken were not just a handful. Dr Kreutz took 64,000 separate CO2 readings at the Geissen weather station over two years. Wattenburg used 310 separate sampling stations; other scientists provided similar amounts of CO2 data.
Since measurements began in 1812, Nobel laureates such as Krogh and Warburg, and their colleagues Haldane, de Saussure, Bunsen, Callendar [who selected the lowest CO2 values and deleted all data outside a ± 10% bandwidth], and other well known scientists collaborated in the project. All took copious notes and made detailed drawings of their test apparatus – something Phil Jones and the rest of the alarmist scientists either consistently neglected to do, or they lost the original data.
If Mann, Briffa, the CRU crew and the rest of today’s grant seeking scientists had the rigor of the 19th century amateurs, they would not be despised for their self-serving gaming of today’s climate industry, while claiming their findings are “robust.” But neither would there be a runaway global warming scare.
For more information on Dr Beck’s paper: click [the site is very interactive; click around to find information].
I have a question about the graph showing heating effect per 20 ppm of CO2: a doubling of CO2, by itself with no forcings or feedbacks, is supposed to raise temps by 1°C by the time 550 ppm is reached, yet the graph only shows about 0.4°C of increase over the same period, why the discrepancy?
We are all climate scientists now!
@Larry Huldén (10:15:33) :
To my knowledge CO2 levels in the Eemian did not exceed current values, which means that 10 ppm/K is a good number for global CO2-outgassing as response to temperature increase. In other words, nothing to worry about.
Corrolary: the dominant cause of CO2 rise is the burning of fossil fuel.
[next time post an excerpt and a link. thanks. ~ ctm
Toyotawhizguy: “Only the water vapor aspect is well understood, and is widely agreed upon as being positive.”
But is this true? I thought that part of the water vapor aspect was more water vapor available to develop cloud cover which would tend to be negative.
Re: Smokey (Mar 8 14:22),
Dr Kreutz took 64,000 separate CO2 readings at the Geissen weather station over two years.
Yes, he did. And they are extremely erratic (Fig 5). They vary up and down between about 310 ppm and 550 ppm. They don’t correlate with Beck’s global figure at all.
He even (Fig 8) shows one of his sites with a 100 ppm variation overnight.
The chemical analysis may have been accurate. But they are not measuring global CO2.
The earth’s temperature has stayed between 12C and 22C for hundreds of millions of years. Is that a true assumption? If true, wouldn’t a strongly negative feedback system having dead-band model it? Such a feedback system would servo to 290 deg K with a +/-5 deg K dead-band (non-linear region) .
AC (13:00:32) :
Larry, Jay, John Finn, RockyRoad, and others who have discussed positive and negative feedback mechanisms:
Is there anything logically wrong with the following AGW position?
1) There are natural negative feedback mechanisms to absorb CO2.
2) These negative feedbacks kept CO2 in check and/or reduced CO2 from previous extremes without causing a runaway hot earth (unchecked positive feedback).
3) The negative feedbacks are now being overwhelmed by man made emissions that are increasing CO2 dramatically faster than in the past.
E.g., something along the lines of what’s being said here:
http://climateprogress.org/2008/04/28/human-driven-co2-rise-14000-times-faster-than-nature-overwhelming-the-slow-negative-feedbacks/
These feedbacks are referring to specifically to the growth of CO2. It could actually be argued that there are both positive and negative feedbacks here. For example, the amount of CO2 produced by fossil fuel burning adds is equivalent to ~3.5 ppm but only ~2 ppm is being added each year. It seems as thoughthe system is responding and at least partly offsetting the increase.
However the CO2 feedbacks (+ve or -ve) simply determine whether we’ll double the pre-industrial level in 2050, say, or 2070 or even 2100. The feedbacks referred to earlier by myself relate to the forcing feedbacks at a given concentration of CO2. It is these feedbacks where there is disagreement. To explain:
If CO2 doubles from 300 ppm to 600 ppm then radiative transfer calculations suggest that this will cause the earth to warm by a bit more than 1 deg. That’s the basic temperature rise due to CO2 alone. Now then, because the surface and atmosphere is warmer it’s possible that increased evaporation will occur. Also a warmer atmosphere can hold more moisture (water vapour) which might mean that the greenhouse effect is amplified further (water vapour is a ghg) and so we get further warming in addition to that from CO2 alone. That is a simplified explanation of why climate models get warming of 3 deg per CO2 doubling. However, the assumption seems to be that all the extra water vapour goes into warming the planet. I’m not convinced by this.
Thanks for the analysis.
I first became convinced that AGW is greatly exaggerated when I found out it relies on positive feedback to magnify any forcing by at least 3. That should surely have meant the earth would have shot off to an extreme, never to return, ages ago. The earth would be either permanently frozen, or boiling hot, unless the forcings were miraculously minute. A volcano would have led to an ice age. The heat from a major asteroid hitting earth would have made the earth being boiling hot for ages.
I started to say in a previous comment that assuming a magnification of 3 times due to feedback is incompatible with a relatively stable system like the earth’s climate, and started to analyse the effect of feedback combined with a logarithmic forcing due to CO2. Someone pointed out that the effect of CO2 can’t be logarithmic since ln(0) is negative infinity. I would say that it’s approximately logarithmic over a wide range where we are, but goes to a very small linear effect at low concentrations. If there was one molecule of CO2 in the atmosphere, and you added a second, the effect would be almost exactly linear since the second order effects would be tiny.
It now seems that the feedback reduces the change to maybe 1/3 of the forcing. Even if there was no feedback opposing changes, ignoring the relatively stability of the earth’s climate, even if we could double the CO2 in the air before it dissolved in the oceans or we went to nuclear power etc, that would mean a rise of about 1.2 degrees Celsius. I think that would make the world a better place, more like the prosperous medieval warming than the cold times of the Great Famine and the Little Ice Age.
When we have accurate temperature measurements over the last century, without “artificial adjustments” and “normalisation”, this would be an interesting calculation:
Calculate the forcing due to CO2 over the last 100 years.
For various assumed feedback magnifications of forcing, calculate the effect of CO2.
Subtract the effect of CO2 from the measured temperatures to get the temperature as determined by natural variation.
Compare the calculated variation for the various assumed magnifications.
The AGW theory is that natural variation is small and CO2 effects are large and dangerous.
Given that it cooled from about 1940 to 1970 when industry got going, and then cooled from 1998 to 2010 when CO2 production was at it’s maximum, I’m sure that large positive magnifications would need more natural variation to fit, and that negative feedback with say 1/3 magnification would need much smaller natural variation. In other words, scary scenarios for the future need a large positive feedback but that’s incompatible with the actual temperatures and CO2 of the 20th century.
George E. Smith (11:32:44) :
George E. Smith (12:42:22) :
Thank you for elucidating so clearly fact that CO2 hypothesis is fallible. Considering the light’s electromagnetic wave properties, the CO2 absorption and radiation account, in the ‘light’ of spectrum’s wavelengths and atom’s energy levels, may be as instructive.
Thanks again.
Smokey (14:22:46) :
You miss the point I was making. I wasn’t suggesting that the ‘Beck’ measurements were wrong or inaccurate I was suggesting they were taken from different locations and so were inconsistent and from locations that were inappropriate.
They are useless in providing any comparsion to the current well-mixed levels. Here’s an example from an Excel file of Beck’s data.
In 1843 CO2 was 308.6 ppm
In 1844 CO2 was 400 ppm
Now it’s quite possible these were both highly accurate readings but I doubt if they were taken from the same location. If we took a measurement from the centre of London or Paris or New York I’m sure it would be well in excess of 400 ppm but it would not be representative of global CO2 concentrations.
Mike J (13:37:49) :
@ P Gosselin (02:19:05) : “I’ve read in literature somewhere that CO2 contributes to about 25% of the greenhouse effect, i.e. 7-8°C. Can you cite where the 10% value comes from?”
You ask a good question. A quick search came up with the following, although it is only 3.6% rather than 10…. Hope it helps.
It doesn’t – it’s nonsense.
Oh, great. Another pseudoscientific article. If someone shows me that net downwards forcing (backradiation) is an observed property of the atmosphere, I’ll show a fraudulent representation of physics.
Also CO2 is NOT a strong absorber of IR. CO2 is much poorer at absorbing heat than air. The rate of emission of CO2 is inversely proportional to its rate of absorption. CO2 temperature always LAGS dry air when equal volumes are heated (with CO2 at 100% concentration). CO2 is a poor absorber of heat period. Compared to water vapor CO2 is insignificant to do anything but provide life to the biosphere.
“AC (13:00:32) :
Larry, Jay, John Finn, RockyRoad, and others who have discussed positive and negative feedback mechanisms:
Is there anything logically wrong with the following AGW position?
1) There are natural negative feedback mechanisms to absorb CO2.”
This is not the way a negative feedback works. A negative feedback simply produces an input to the system with the opposite polarity of the output, and depending on the strength of the negative feedback this might reduce amplification or null it altogether. An example would be: Rising CO2 level leads to a fall in humidity according to F. Miskolczi’s theory. But the physical mechanism is not that important: Important is that negative feedback can be independent of absorption of CO2.
“2) These negative feedbacks kept CO2 in check and/or reduced CO2 from previous extremes without causing a runaway hot earth (unchecked positive feedback).”
The effect of a negative feedback can be what you described here.
“3) The negative feedbacks are now being overwhelmed by man made emissions that are increasing CO2 dramatically faster than in the past.”
A simple linear negative feedback is proportional to the output of the system, so the stronger the output rises, the stronger the negative value fed back. So, no, it can’t be overwhelmed.
Of course the feedback might be nonlinear, might have a time lag associated with it (in a physical system the size of the earth, probably a noticeable one on the order of at least days if not months, years or decades), might be a logarithmic response etc…
It’s difficult to say without a model of a physical mechanism. The AGW scientists have never talked much about negative feedbacks or i didn’t listen, i always hear “positive feedback” from them… Miskolczi, Lindzen, Eschenbach have described negative feedback mechanisms.
For a stable system, the negative feedback must have an amplification factor between 0 and -1 i would say; a greater negative value would lead to rapid and amplifying oscillations (ever greater extremes, which we don’t observe).
A consequence would be that the input perturbation – the warming of the surface through increased CO2 – would not be entirely compensated: The output of the system must be perturbed slightly to be able to feed back a compensation value. So a negative feedback close to -1 would lead to a near-compensation of the “warming due to increased CO2 ‘forcing'”, but not compensate it completely.
(My usual model of a negatively fed back operational amplifier – i don’t know whether any “credible climatologist” (of the Hansen school of thought, i hope that is not taken as an insult) ever thought about it this way; or whether they even know about negative feedbacks)
HTH
I keep reading that greenhouse gases are the reason the average temperature of the Earth is approximately 33 degrees K (or C) higher than the average temperature would be in the absence of greenhouse gases. Just like Juraj V. (06:54:22), I find this hard to believe. My reasons for disbelief are as follows.
(1) I’ll assume the average temperature of the Earth is 15 degrees C or 288 degrees K. Subtracting 33 degrees C gives a temperature of -18 degrees C or 255 degrees K. Thus, for greenhouse gases to warm the Earth 33 degrees C, the average temperature of the Earth in the absence of greenhouse gases must be 255 degrees K.
I believe the argument for a “greenhouse-gasless” average Earth temperature of 255 degrees Kelvin is based on five assumptions: (a) the Earth’s surface acts like a “grey body” absorber/radiator, (b) the temperature of the surface of the Earth is everywhere the same (both day/night and at all latitudes/longitudes), (c) the average albedo of the Earth is approximately 0.3–which implies an average absorptivity of approximately 0.7, (d) the emissivity of the Earth is unity, and (e) the Earth exists in a directional electromagnetic radiation field having a power density of approximately 1,367 Watts per square meter. The computation of the power absorbed by the Earth is the product of (i) the incident power density, (ii) the average Earth absorptivity, and (iii) the cross-sectional area of the Earth (pi times the radius of the Earth squared). The computation of the power radiated by the Earth is the product of (i) the temperature of the Earth in degrees Kelvin to the fourth power, (ii) the surface area of the Earth (4 times pi times the radius of the Earth squared), (iii) the Stefan-Boltzmann constant, and (iv) the average Earth emissivity. Setting these two powers equal and solving for temperature one gets approximately 255 degrees K for the temperature of the Earth.
A critical flaw with this approach is that for thermal radiation from “grey body” surfaces, the principle of detailed balance (which is a qualitative form of Kirchoff’s law) requires that the emissivity and the absorptivity of a surface be equal. Thus, it is inappropriate to simultaneously use an absorptivity of 0.7 and an emissivity of 1. When the preceding model is used with the single change that the average absorptivity equals the average emissivity, the Earth’s temperature is approximately 278 degrees K, not 255 degrees K; and provided the absorptivity is not zero, the temperature is independent of the absorptivity.
This still leaves 10 degrees C to be accounted for; but not 33 degrees C as is often claimed.
(2) Then like Ron E Seal (06:28:48) and Ken Coffman (07:05:02) have pointed out, the presence of an atmosphere (greenhouse or otherwise) will have an effect on the Earth’s average temperature. In the first place, the surface of the Earth can no longer be treated as a “grey body” radiator. Electromagnetic radiation through and by gases voids the use of grey body radiation laws–conduction and convection must be taken into account. I believe such computations are extremely complex–especially for a non-inertial (rotating) Earth. As such, it seems eminently reasonable that an atmosphere like the Earth’s but devoid of all greenhouse gases might raise the average surface temperature of the Earth 10 degrees C above what it would be in the absence of an atmosphere.
Bottom line, I see little or no justification in Mr. Archibald’s statement: “The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere…“
Hmmm … I sometimes wonder if these posts (head post + ensuing discussion) aren’t some sort of over-all general competency test … doing a word-search on the volume of text and posts above, I found zero mention of the following terms WHICH underpin the of physics of ‘radiational forcing’ that CO2 (and H2O vapor) are intimately involved insofar as the surface-to-space energy budget.
“Atmospheric window” – an area in/about 10 um that enjoys a clear view from surface to space (save for moderate to heavy overcast/clouds). Coincidentally, the ‘warm earth’ produces a spectral peak in the Planck curve in this atmospheric window especially as warmer earth surface temperatures. The spectrum either side of this window are bracketed by (variable amounts of) water vapor and CO2 absorption (which also serve to determine how wide this ‘window’ ultimately is)
“Planck’s curve” – a curve denoting wavelength versus spectral emission (radiation, as a verb) strength. Notably, the spectral energy in this curve is proportional to Temperature to the 4th power.
“Wein’s Law” – calculates where the peak wavelength occurring in Planck’s curve, which for a 288 to 290 K earth peaks in/about 10 um wavelength atmospheric window (see above)
I note that MODTRAN is used in the first graph to depict ‘net downward forcing’ energy; MODTRAN can also be used for calculating ‘upwelling’ LWIR radiation from the earth’s surface should internally be using Planck’s Law and the ‘spectral opening’ at 10 um to determine the energy budget/energy flow into space
An interesting experiment of the student: Using MODTRAN plot David Archibald’s graph axis for CO2 (ppm) versus a fixed earth surface temperature; (is IT, the resulting func logarithmic? what does a delta change in temperature vs total W/m2 upwelling LWIR look like?)
.
.
Re: Percentage contribution from CO2 to greenhouse effect.
Ididn’t particualrly want to get into this but here goes anyway.
Because of overlaps in the absorbing spectra, calculating the effect any particular gas is not straightforward. The best way to illustrate this is to look at a hypothetical case or thought experiment.
If CO2 were removed from the atmosphere while leaving all other ghgs at the same concentrations then we would be left with 91% of the current greenhouse effect. However, if all other ghgs were removed leaving only CO2 then 26% of the current greenhouse effect would remain. The CO2 contribution, therefore, is somewhere between 9% and 26% of the total. But (and it ‘s a big but) if we removed CO2 thus cooling the atmosphere it’s unlikely that the water vapour concentration would remain constant.
“AC (13:00:32) :
Example of +ve feedback as proposed by AGW
doubling CO2 from 280ppm to 560ppm = 3.7 watts/m2 extra juice “kept in”
3.7 w/m2 = +1 degree C
max water vapour about doubles with every +10 degree C
water vapour is a greenhouse gas
extra water vapour from +1 degree C = 7.4 w/m2
CO2 plus positive feedback = 3 degrees
(over simplification but you get the idea)
Example of -ve feedback
+3 degrees temperature rise
earth surface radiates power (in theory) = constant x T(degrees K) ^4
or P=C*T*T*T*T
so +3 degrees at 0 C = 14.3 w/m2
but +3 degrees at 20 C = 17.7 w/m2
so the warmer it gets, the FASTER the rate at which the earth sends heat to space goes up. Now it is of course much more complex than that, but it is easy to see that the +ve inputs can only raise temperature for so long before the -ve inputs overwhelm them.
Bravo, Reed Coray! It’s just amazing how many lapses in phyical reasoning are encapsulated in the usual, simplistic, radiation-only view of Earth’s thermodynamics. You’d think that those who call themselves climate scientists had never heard of enthalpy or understand that evaporation from the oceans necessarily cools the surface. All this without even touching the misguided notion of “positive feedback.”
One of the things I’m finding interesting about this thread is that Dr. Svalgaard has not yet turned up to give a thump to Dr. Archibald. One of these days those two Renaissance Men will get together on something they agree on and set us all back on our heels. I’m waiting for the day. In the mean time, I sit and learn.
John Finn (14:48:33) :
“Also a warmer atmosphere can hold more moisture (water vapour) which might mean that the greenhouse effect is amplified further (water vapour is a ghg) and so we get further warming in addition to that from CO2 alone. That is a simplified explanation of why climate models get warming of 3 deg per CO2 doubling. However, the assumption seems to be that all the extra water vapour goes into warming the planet. I’m not convinced by this.”
See my comment at 12:41:13. If there is a logarithmic relationship between temperature increase and concentration of water vapor, then how could any small addition of water vapor caused by the additional heat from CO2 be significant?
I agree with your last two sentences quoted above. I think folks l
”
Bill S (13:20:36) :
I was reading here ( http://www.aip.org/history/climate/simple.htm ) that viewing the atmosphere as a series of distinct layers as opposed to as a single “slab” increases the likelihood that adding more CO2 will cause more radiative absorption. If CO2 doesn’t “capture” the outgoing radiation in one layer, a higher layer might do so, and still “trap the heat”.
The layer suggestion might hold up better in the stratosphere, but I know next to nothing about the stratosphere. Can anyone enlighten me in this area?
”
Bill, a multislab situation provides more accuracy because each has its own temperature, pressure, and gas concentrations. It doesn’t mean though there’s more chance to capture – in fact – it’s less. As pressure drops, the lines become narrower so there’s less energy that can be collected. Also, each slab has far less material than the whole so there’s still only so many molecules of co2 between here and the top of the atmosphere.
Another factor is that for the troposphere and most all of the stratosphere and thermosphere, there is radiation away from the slab as well as absorbed by the slab. In fact, the lapse rate is related to this as a conservation of energy. Lower down, when surrounded by slabs above and below that are similar in temperatures, there is a bit of equilibrium going on – or so it would seem. Higher up, you’ve got all the radiation coming through the slab (in the LWR arena) coming from below. One can approximate with the stefan’s law grey body concept. Stefan’s law is for radiation in a hemisphere and there are two hemispheres – the outbound and the inbound. It’s got to radiate equally in both directions and the energy has to balance with what is absorbed, which is essentially only from below as you get higher – as there’s low lwr coming down so there’s got to be a T drop – unless there’s some additional energy coming in.
General comment – I am rereading Tommy Gold’s Deep Hot Biosphere and his chapter on the carbon cycle is now extremely relevant – put very simply, in order for life to exist on Earth, apart from having a massive atmosphere which ensures the presence of liquid water, CO2 is continually extracted from the atmosphere and precipitated into sediments, coral reefs etc. This requires a fresh source of CO2 that Gold proposes comes via the breakdown of hydrocarbons by a deep hot biosphere which then emits, mainly methane, and some CO2.
So the existence of life on the Earth’s surface that is dependent on photosynthesis for its existence, and consumes carbohydrates, actually relies on an even deeper biosphere that feeds on upwelling hydrocarbons whose metabolising products are methane and hence CO2 which feed the surface biosphere.
To paraphrase Obiwan Kenobi, we are in a symbiotic relationship with the deep hot biosphere, surely you must understand that! 🙂
”
Reed Coray (15:25:22) :
..
A critical flaw with this approach is that for thermal radiation from “grey body” surfaces, the principle of detailed balance (which is a qualitative form of Kirchoff’s law) requires that the emissivity and the absorptivity of a surface be equal. Thus, it is inappropriate to simultaneously use an absorptivity of 0.7 and an emissivity of 1. When the preceding model is used with the single change that the average absorptivity equals the average emissivity, the Earth’s temperature is approximately 278 degrees K, not 255 degrees K; and provided the absorptivity is not zero, the temperature is independent of the absorptivity.
This still leaves 10 degrees C to be accounted for; but not 33 degrees C as is often claimed.
(2) Then like Ron E Seal (06:28:48) and Ken Coffman (07:05:02) have pointed out, the presence of an atmosphere (greenhouse or otherwise) will have an effect on the Earth’s average temperature. In the first place, the surface of the Earth can no longer be treated as a “grey body” radiator. Electromagnetic radiation through and by gases voids the use of grey body radiation laws–conduction and convection must be taken into account. I believe such computations are extremely complex–especially for a non-inertial (rotating) Earth. As such, it seems eminently reasonable that an atmosphere like the Earth’s but devoid of all greenhouse gases might raise the average surface temperature of the Earth 10 degrees C above what it would be in the absence of an atmosphere.
Bottom line, I see little or no justification in Mr. Archibald’s statement: “The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere…“
”
Emissivity and the grey body assumption are an engineering approximation. In reality, one should expect the body to have emissivity and absorption by wavelength to be consistent at each wavelength. Note, incoming solar is for a planck curve of about 6000k and peaks around 500 nm. The albedo is 0.7. The Earth is radiating outward at a T of near 288k and it is radiating totally in the longwave IR. The effective emissivity is going to be approximately 1 at the lwr. Note too that the albedo of 0.7 is a combination of surface and cloud albedo and the actual average surface albedo is around 0.08 while the clouds contribute around 0.22 so in no way do you have a problem here.
One does have the problem of such things being radiative only – but then the idea is to conceptually explore the conditions associated with such. Around 100 w/m^2 is the convection and water vapor cycle. any increase in T results in increases of convection and evaporation. It’s not that big a deal to assume an average or typical value or look at radiative only as that is a best case (actually worst case) scenario for problems in transfer of heat. Since the surfac an d most Ts in the atmosphere are triple digit – 200-400 K, one also can deal more with pertubations than having to worry about individual calculations for every variation above or below the mean with T^4 rather than T.
The figure of 1DegC warming for a 3.5W/m^2 increase in Radiative Forcing (which the IPCC makes clear is a forcing at the Tropopause) is for the Tropopause area only.
At the surface, the sensitivity is between 0.095 and 0.15 DegC/W/m^2, depending on the assumption you make for evaporation (there is a wide range of views – the mainstream seems to lie between 2% and 6.5% increase per DegC).
So the same forcing translated to the surface would produce an extremely worrying 0.3to 0.5 DegC temperature rise, implying a 1% to 3% increase in water vapour.
To maintain the median IPCC forecast of 3DegC at the SURFACE, the implied conditons at the surface are:
1. Evaporation increased between 6% and 20%.
2. Surface Forcing increased by between 21W/m^2 and 32W/m^2
So we have the situation, according to the Proponents, that a doubling of CO2 causes a radiative imbalance of 3.5W/m2 at the Tropopause. This Radiative Forcing translates to an increase in Surface Forcing (at equilibrium- this is not a transient) of between 21-32W/m^2.
In detail, how is this increased forcing maintained? Where is the accounting of it, Watt by Watt?
The global warming theory does provide a number of testable hypothesis. Generally each component of the following assumptions can be tested. This may be a new explanation of global warming theory for some of you.
1) If CO2/GHGs double, there should be an increased forcing of 4.0 watts/metre2 at the tropopause emission layer which is now 255K or 240 watts/m2 (on average 5 kms up, not the surface);
2) If there is an increase of 4.0 watts/m2 at the tropopause emission layer, temperatures at that layer will increase by 1.2C (according to the Stefan Boltzmann equations).
3) If temperatures increase by 1.2C at the (former level of the) tropopause emission layer, water vapour will increase providing an additional indirect 4.0 watts/m2 of forcing.
4) If there is 8.0 additional watts/m2 of forcing at the tropopause emission layer, another 1.75 watts/m2 of indirect and surface albedo affects will appear in the long-run and (and another 1.75 watt/m2 of humidity forcing will result from those indirect effects) and, in total there will now be 11.5 extra watts of forcing at the emission layer.
5) If there is an extra 11.5 watts/m2 at the layer which was 255K or 240 watts/m2, temperatures at this layer will increase by 3.0C according to the Stefan Boltzmann equation.
6) If temperatures increase by 3.0C at the former level of the tropopause emission layer, the layer itself will increase in height by 461 metres. This newer higher emission layer will still be in equilibrium (over the long-term) with the solar forcing of 240 watts/m2.
7) If the tropopause emission layer is now 461 metres higher, and if the adiabatic lapse rate of 6.5C/km stays constant, the surface temperature will now increase by the same 3.0C .
8) And thus we have 3.0C per GHG doubling of 4 watts/m2 (or a impact of 0.75C/watt/m2).
There is your global warming theory in a nutshell which is not really explained anywhere else like this that I have seen.
We can test all of these assumptions:
1) humidity levels are not increasing at the tropopause emission layer.
2) the adiabatic lapse rate should not be considered as a never-changing entity. The Stefan Boltzmann equations predict that it should increase slightly as the temperatures increase so that the surface should only warm by a little more than half of the tropopause.
3) I have never seen a proof of Myhre’s GHG doubling forcing estimates.
John Finn (15:43:17)
‘The CO2 contribution, therefore, is somewhere between 9% and 26% of the total. But (and it ’s a big but) if we removed CO2 thus cooling the atmosphere it’s unlikely that the water vapour concentration would remain constant.
That’s a “BIG IF” taking in the power of wind.
John Finn (04:44:49) : Thanks for your clarification. I was actually pointing out that, while people here seem quite happy to attribute fluctuations in the climate to solar cycles (and also the LIA), they don’t seem aware just how small the change in energy input needs to be to cause that change. As you point out, the increased energy retention brought on by CO2 doubling is actually bigger than the much touted “it’s the sun, stupid”.
Sergey (09:37:55) :
The very premise of this article that 30C increase in surface temperature is explained by greenhous effect is wrong. This difference is due to convection.
Thank you. Convection trumps radiative effects in every complex system. Why the effect seen in the backwards derivation of the magical properties of CO2 I don’t know.
Considering the history and persistance of this line of reasoning I don’t blame David for putting forward this intellectual argument.
There is only one comment I haven’t made yet and that is given the logarithmic effect of CO2, I suppose if we remove it from the atmosphere its effect goes to infinity 😀 … so like many have noted here, until I see some empirical experiment that shows something interesting and not some assumption laden model based derivation disguised as an experiment … the CO2 effect is ZERO in my mind and simply does not exist. It is only a small part of layers of a mixed gases of certain densities of the layered fluids that blanket the surface of the Earth and the phenomena we are observing should be renamed the ‘Blanket Effect’.
Ben W (05:57:46), HelmutU (06:44:57) and a number of other comments seem to have hit on the biggest problem with the CO2 graphs. David Archibald’s explanation of the diminishing logarithmic effect of CO2 is reasonable, however accepting claims of pre-industrial levels for CO2 of 280 ppm seems to have little foundation.
Splicing under sampled and inappropriate tree ring data to cherry picked UHI contaminated surface station readings produced temperature graphs showing “unprecedented warming”. These were offered as valid reconstructions by advocate scientists who intentionally hid the divergence between the two sets of rubbish data where they overlapped.
Splicing ice core readings from CO2 poor areas of the planet in which CO2 is not evenly mixed in the atmosphere with modern readings taken from the side of an active volcano produced graphs showing rapid increases in CO2. These were offered as valid reconstructions by advocate scientists who have intentionally ignored the large number of direct chemical measurements from the last 200 years that diverged from their ice core proxy data.
Same “Climate Science”, different bucket.
Jan Pompe (08:34:26) :
Hi Jan,
I’m happy to see your name here!
Here’s a bit from John Christy on benefits of co2,
Gene
I do not accept that pre-industrial CO2 was 280 ppm.
That is another of the Climate-gate lies. Dr. Callendar and early CAGW proponent apparently successfully sold the idea that we could not trust the laboratory measurements of CO2 in the 1800s. Why? Because they measured atmospheric CO2 not 280 parts per million but varying over the place, from 330 -440 ppm, as Georg Beck showed.
The AGW Cassandras would rather read and realy on ice core proxies or chicken entrails, instead of of lab measurements. Scientists of two centuries ago conducted atmospheric composition studies and 93,000 measurements from lots of scientific teams publishing in scientific journals then, revealed that and also showed the rises due to the massive Tambora and Krakatoa volcanic eruptions.
We would be puzzled when comparing the Vostok ice core samples with their publications, were it not for Dr. Zbiegniew Jaworowski, the IPCC past ice core chairman, recognized for his world-leading ice core expertise. He said CO2 readily forms hydrates at modest pressure as in buried ice. It forms such hydrates and then stops at 280ppm, in the air bubbles in the ice.
He insisted that ice core readings had to be corrected for this effect to get a correct reading. But this is not done, and they have succeeded in convincing you that 280- ppm is the pre-industrial level, when it is not. The Moana Loa labs Loa-gate, created the image that the Vostok readings are accurate when they matched CO2 readings. But in reality, they merged data separated by 83 years to match and show a continuously rising curve. It is a pure scandal and bunk.
Reed Coray (15:25:22) :
A critical flaw with this approach is that for thermal radiation from “grey body” surfaces, the principle of detailed balance (which is a qualitative form of Kirchoff’s law) requires that the emissivity and the absorptivity of a surface be equal. Thus, it is inappropriate to simultaneously use an absorptivity of 0.7 and an emissivity of 1. When the preceding model is used with the single change that the average absorptivity equals the average emissivity, the Earth’s temperature is approximately 278 degrees K, not 255 degrees K; and provided the absorptivity is not zero, the temperature is independent of the absorptivity.
No, the critical flaw with your approach is that the frequency range of the insolation is not the same as the frequency range of the emission. Therefore it is quite acceptable to use an absorptivity of 0.7 and an emissivity of 1 (the correct values).
George E. Smith (12:42:22)
I think that’s the reason why we stopped using plain air between the 2X4 walls and decided to encase the air in fibers for insulation.
It seems that about everyone knows that the “greenhouse gas hypothesis” should not be equated to what really happens in an actual greenhouse, because it ignores convection. Well, folks, the “atmospheric greenhouse gas hypothesis” suffers the same problem, IMHO.
Re: Bill Illis (Mar 8 17:11),
“If temperatures increase by 1.2C at the (former level of the) tropopause emission layer, water vapour will increase”
??? How? At the surface warming leads to more water because of evaporation from the surface. But what is the source up there?
Well, that explains why the poles are so warm …
Wait; maybe not. Just the converse (To paraphrase: ” It’s the LWIR, s***** ” ) …
The ‘convectionists’ need to explain this one outside of exalted convectionist doctrine.
.
.
“”
Colin Davidson (17:09:44) :
The figure of 1DegC warming for a 3.5W/m^2 increase in Radiative Forcing (which the IPCC makes clear is a forcing at the Tropopause) is for the Tropopause area only…..
“”
At the tropopause (assuming std 1976 atm values), one sees 3.7w/m^2 decrease in transmitted IR from the surface. For the atmosphere, it seems that the actual average sensitivity is around 0.22 K rise per w/m^2 increase. For 3K that’s about 14 w/m^2 increase. THe number comes from the avg values associated with Earth – 33 K rise due to atmosphere, 288.2k avg surface T, 235w/m^2 average emission to balance the 235 avg incoming solar with an absorption of around 150 w/m^2 (which includes cloudy skies not just clear sky conditions). This also accommodates the avg contribution of convection.
for the co2 doubling, this is 3.7 w/m^2. Assuming a 5 K rise in column T, the absolute humidity should increase by 30% which corresponds to less than another 3.7 W/m^2 contribution to the needed forcing. At 0.22 sensitivity. we’ve got less than a 1.7 K rise in T which means the h2o vapor is contribution is way too small to generate anything close to what is needed. Consequently, we’re missing almost 3 1/2 deg. of the original 5k presumed temperature increase (for the h2o increase calculation).
What happens above the tropopause (and below) is also interesting. Increasing the absorption means increasing the emissivity. The atmosphere radiates more at the same temperature. By 70 to 100 km altitude, note also that the co2 doubling difference is back down to just over 2W/m^2 (or so I seem to recall at the moment). The lapse rate depends now upon the conservation of energy. Increases in ghgs mean increases in emissivity and hence a drop in T due to the need for energy balance.
JAE (12:41:13) :
If the GHG effect of CO2 is logarithmic, then so is it for HOH, yes? If so, then we are so “far-out” on the curve that any type of “water vapor feedback” is not possible. No?
No. A weak absorber (Freon in atmosphere) is ~linear (Beer’s Law), moderately strong (e.g. CO2) is ~log, and strong (e.g. CH4 or N2O) is ~ square root