I received this presentation of the “Bjerknes Lecture” that Dr. James Hansen gave at the annual meeting of the American Geophysical Union on December 17th. There are the usual things one might expect in the presentation, such as this slide which shows 2008 on the left with the anomalously warm Siberia and the Antarctic peninsula:
Source: James Hansen, GISS
Off topic but relevant, NASA has recently “disappeared”updated this oft cited map showing warming on the Antarctic peninsula and cooling of the interior:
There is also some new information in Hansen’s presentation, including a claim about CO2 sensitivity and coal causing a “runaway greenhouse effect”.
Hansen makes a bold statement that he has empirically derived CO2 sensitivity of our global climate system. I had to chuckle though, about the claim “Paleo yields precise result”. Apparently Jim hasn’t quite got the message yet that Michael Mann’s paleo results are, well, dubious, or that trees are better indicators of precipitation than temperature.
In fact in the later slide text he claims he’s “nailed” it:
He adds some caveats for the 2xCO2 claim:
Notes:
(1)
It is unwise to attempt to treat glacial-interglacial aerosol changes as a specified boundary condition (as per Hansen et al. 1984), because aerosols are inhomogeneously distributed, and their forcing depends strongly on aerosol altitude and aerosol absorbtivity, all poorly known. But why even attempt that? Human-made aerosol changes are a forcing, but aerosol changes in response to climate change are a fast feedback.
(2)
The accuracy of our knowledge of climate sensitivity is set by our best source of information, not by bad sources. Estimates of climate sensitivity based on the last 100 years of climate change are practically worthless, because we do not know the net climate forcing. Also, transient change is much less sensitive than the equilibrium response and the transient response is affected by uncertainty in ocean mixing.
(3)
Although, in general, climate sensitivity is a function of the climate state, the fast feedback sensitivity is just as great going toward warmer climate as it is going toward colder climate. Slow feedbacks (ice sheet changes, greenhouse gas changes) are more sensitive to the climate state.
Hansen is also talking about the “runaway” greenhouse effect, citing that old standby Venus in part of his presentation. He claims that coal and tar sands will be our undoing:
Hansen writes:
In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect. If we also burn the tar sands and tar shale (a.k.a. oil shale), I think it is a dead certainty.
That would be the ultimate Faustian bargain. Mephistopheles would carry off shrieking not only the robber barons, but, unfortunately and permanently, all life on the planet.
I have to wonder though, if he really believes what he is saying. Perhaps he’s never seen this graph for CO2 from Bill Illis and the response it gives to IR radiation (and thus temperature) as it increases:
It’s commonly known that CO2’s radiative return response is logarithmic with increasing concentration, so I don’t understand how Hansen thinks that it will be the cause of a runaway effect. The physics dictate that the temperature response curve of the atmosphere will be getting flatter as CO2 increases. Earth has also had much higher concentrations of CO2 in past history, and we didn’t go into runaway then:
Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ).
There’s lots more in this paper to behold in wonderment, and I haven’t the time today to comment on all of it, so I’ll just leave it up to the readers of this forum to bring out the relevant issues for discussion.
I’m sure Steve McIntyre at Climate Audit will have some comments on it, even though his name is not mentioned in the presentation. My name was mentioned several times though. 😉
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Manfred
December 25, 2008 3:42 pm
Joel Shoer wrote:
“…I also hold no illusions that I will be able to convince everyone. There are people around (commenting on this very website, in fact) who still don’t believe that CFCs impact the ozone layer…”
To convince others, you may have to rethink your attitude towards science.
Recently, the first experiment to measure the CFCs impact on the ozone layer has demonstrated, that the previously assumed and computer simulated mechanism was at least one order of magnitude weaker than expected. It shurely takes more exerimental data to confirm this, but presently experimental evidence is not supporting previous consensus.
The author of the peer reviewed papaer therefore stated, that scientific consensus was shattered and that science may have to to start all over again.
Therefore I can’t follow your remark ridiculing others, who feel more comfortable with experimental evidence than computer models.
foinavon
December 25, 2008 3:45 pm
Bill Illis (05:37:46) :
You’ve misunderstood again. I’m not “crapping” on your formula at all. You should try to read posts carefully because very often the writers make an effort to say clearly what they mean! Go back to my post [21:12:08 (12:52:53)] and you’ll see that I pointed out that my equation was essentially the same as yours[***].
The problem is with your representation of the data in the article at the top of this thread. It is highly misleading in relation to the issue at hand which is the effect of raising atmospheric CO2 levels by very large amounts. The only reason I can think of that anyone would represent the temperature variation expected with CO2 variations, starting from near 0 ppm is to create the impression that increasing CO2 from today’s levels would have little effect, since the data is massively dominated by the completely irrelevant range between 0 and 100 ppm.
That’s very misleading. Therefore I included an equation so that anyone sufficiently interested could address this themselves, for example by calculating (in Excel, for example) the CO2/temp relationship (within a 3 oC climate sensitivity) over the range 280-600/700 ppm (e.g. to assess what might acrue during this century if we don’t make an effort to limit or sequester emissions), or the range 280-3000 ppm, if we seriously want to address Hansen’s “burning all the coal and tar-sands” scenario.
The other problem with your graph has already been highlighted very well by Chris V, which is the extremely well-understood fact that the climate sensitivity relates to the temperature increase at equilibrium. You’ve chosen to ignore that in your red plot it seems.
[***]my equation is rather better than yours (!) since it is transparent and versatile. I’ve kept the values for the climate sensitivity and the temperature normalization independently-defined, so that the equation can be used to assess the effects of any chosen climate sensitivity (3.0 below) and any chosen normalization (9.39 below which gives an absolute temperature of 15oC at 280 ppm). That doesn’t make it “complicated”!
T = (3.0/log(2))*(log(C))-9.39
Peter
December 25, 2008 3:52 pm
Joel Shore:
More precisely, the concentration of water vapor is dependent on the temperature. So, as the direct effect of the CO2 causes temperatures to rise, the concentration of water vapor increases and you get additional warming
The temperature increase is from the total greenhouse effect of all greenhouse gases – including water vapor and CO2.
Over the oceans, the water vapor is already there – its presence doesn’t depend on the presence of CO2 – and its greenhouse effect is very large compared to that of CO2, and even larger compared with the added CO2.
So almost all of the greenhouse warming effect, from the time the sun rises and starts warming the ocean, is due to the water vapor itself.
foinavon
December 25, 2008 4:13 pm
Wondering Aloud (07:22:50)
I described the problem here [22.12.08 (10:47:01)]
The truncated version of Scotese’s graph in the article at the top of this thread is an extremely crude and outdated sketch of temperature in the deep past. I don’t know where the data has come from. Do you? We’d surely like to know that, but I can’t find it on Scotese’s site. It’s O.K in the context of Scotese’s very nice site on paeogeology (the version on his site is somewhat better. But it doesn’t bear much relation to our current understanding of paleotemperature and it certainly shouldn’t be used alongside the CO2 model (time resolution of the model one data point every 10 million years) to “assess” the relationships between temperature and CO2 levels in the past. We can only do that where we have contemporaneous proxies for CO2 and temperature.
There’s a wealth of paleotemperature data in the scientific literature. Even this version on Wikipedia is sufficient to illustrate that the truncated Scotese sketch is not very scientific (and we can see where the data comes from!): http://en.wikipedia.org/wiki/File:All_palaeotemps.png
Phil
December 25, 2008 4:18 pm
Joel Shore (14:28:34) :
“More precisely, the concentration of water vapor is dependent on the temperature. So, as the direct effect of the CO2 causes temperatures to rise, the concentration of water vapor increases and you get additional warming (a positive feedback) from that. Of course, if something else other than CO2 (like an increase in solar irradiance) caused the initial warming, you would still get the same water vapor feedback effect…It is not specific to the cause of the warming being CO2.”
Please help me understand this a little better. I understand that the amount of water that air can hold is dependent on temperature (by the way, the link didn’t come through). That much is clear. My question is: what is the formula that governs how additional CO2 puts more water vapor into the air and what is the mechanism by which that is asserted to happen? That is why I asked what the climate sensitivity is asserted to be for CO2 without water vapor, under the assumption (perhaps misunderstood) that there would then be a formulaic relationship that would add the water feedback in, thus resulting in the asserted 3°C per doubling of CO2. What are the intermediate steps expressed mathematically?
Bill Illis
December 25, 2008 4:34 pm
foinavon, the formula is important at the lower end of the CO2 spectrum as well because it tells you something important about the expected relative humidity response of warming/GHGs.
The formula at the extremes of the possible responses says that CO2/GHGs are responsible for nearly the entire greenhouse effect (when the secondary impact on water vapour is included).
That says the assumptions included in the formulas and in the models is based on relative humidity staying broadly constant. If that is not expected to occur at the extremes, then maybe it is not accurate for the current spectrum of CO2/GHG values as well.
If the formula does not hold through all possible values then how can we be sure it is valid for the current spectrum of values.
What if relative humidity declines by 10% (4 percentage points) as GHGs reach their equilibrium forcing level. Warming then only amounts to 1.5C rather than 3.0C.
I spelled this out in another chart more than a month ago (some of the values in the chart have changed since then.) http://i463.photobucket.com/albums/qq360/Bill-illis/LackofWarmingExplained.png
Chris V.
December 25, 2008 4:34 pm
Manfred (15:42:52) wrote:
“Recently, the first experiment to measure the CFCs impact on the ozone layer has demonstrated, that the previously assumed and computer simulated mechanism was at least one order of magnitude weaker than expected.”
I can’t find anything about this. Link?
John Philip
December 25, 2008 5:49 pm
Rather confusingly Mr Wilde is a Fellow of the Royal Meteorological Society however he is not entitled to use the FRMetSoc designation that indicates professional Meteorological experience or competence.
The rules changed in 2003, before that it was possible for an enthusiastic layman or amateur to become a Fellow without any verified proof of Meteorological aptitude. Existing Fellows were not relieved of their title at the time of the rule change and may continue to use it as an honorarium.
To be fair Wilde makes this clear in the first article of his series on CO2Sceptics site, yet still starts many subsequent pieces with Stephen Wilde has been a Fellow of the Royal Meteorological Society since 1968. which is bound to lead the casual reader to infer that they are reading a piece by a professional Meteorologist rather than an amateur.
I too was struck by the contrast between this claim of Wilde’s academic recognition and the many errors of basic science in his writings, which led to an exchange with Mr Wilde on this very blog …
[Comments 09:02:38 onwards]
Hope this unmuddies the waters a little.
JP.
Joseph
December 25, 2008 5:50 pm
<Re: Joel Shore (14:28:34) says
Not sure where you get this from. It is an elementary physics problem to work out that the blackbody radiative temperature of the earth (having the albedo of ~30% in the visible that it does) corresponds to about -18 C (or 255 K). The reason why the average surface temperatures are significantly warmer than this (~15 C) is because of the greenhouse effect.
————————————————————
No. That is incorrect. Your invocation of the blackbody radiative temperature of the earth concerns the radiation of our planet and the atmosphere, taken as a whole (the biosphere), radiating into space. That IS in radiative equilibrium, with the temperature of the system as you stated. My discussion with foinavon concerns the transfer of heat from the planet’s surface (the ocean) to the atmosphere, within that system, not our biosphere’s blackbody temperature, or radiation of heat into space. The transfer of heat from our planet’s surface to the upper atmosphere is mostly convective, not radiative.
You are also mistaken concerning the nature of the greenhouse effect. Did you visit the links I provided? If there was no greenhouse effect to transport the heat away from our planet’s surface towards the upper atmosphere and the poles, primarily through convection, our planet’s surface temperature would average approximately 170 °F.
Our biosphere is unequally heated by the sun. The greenhouse effect acts to transport heat from areas where there is more heat to areas where there is less heat, both horizontally across the planet’s surface and vertically within the atmosphere. The greenhouse effect also acts to ameliorate the difference between daytime highs and nighttime lows.
Have you ever been to a desert area? The air there is very dry. It’s the reason why it can be blisteringly hot during the day, and still drop below freezing at night. Very little greenhouse effect.
Cheers!
Joel Shore
December 25, 2008 6:41 pm
Peter says:
The temperature increase is from the total greenhouse effect of all greenhouse gases – including water vapor and CO2.
Well, we are simply talking about different things. Looking back at the original post that I was responding to, it was talking about increasing CO2 levels and the water vapor feedback, not the original of the entire natural greenhouse effect. I agree that the large majority of the natural greenhouse effect is due to water vapor. (It is hard to ascribe a rigorous percentage of the effect to water vapor and CO2 because the effects are not additive.)
By the way, I noticed in looking back at Phil’s original post that I never did answer this question of his:
If the climate sensitivity is asserted to be 3°C per doubling of CO2, WITH water feedback, what is the climate sensitivity per doubling of CO2 WITHOUT water feedback supposed to be?
Well, the “bare radiative effect” of doubling CO2 is to increase the temperature by about 1.1 C, give or take about a tenth of a degree. However, the water vapor feedback isn’t the only feedback effect to consider. There are other positive feedbacks like the ice-albedo feedback (land and sea ice melting makes the earth less reflective so it absorbs more solar energy), negative feedbacks like the the lapse rate feedback that I mentioned above, and then there is of course the feedback due to clouds. The cloud feedback is currently the biggest source of uncertainty and differences between the models.
Joseph
December 25, 2008 6:42 pm
Re: foinavon (15:17:50)
foinavon, I think you are confused. Atmospheric changes that result in a reduction of the transfer of the heat from the ocean to the atmosphere does not translate into; “Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.”. Reduced cooling does not mean warming. The ocean is heated by the sun. Changes in the atmosphere cannot add additional heat to the ocean, it can only affect the rate at which heat is lost from the ocean, nothing more.
Jeff Alberts
December 25, 2008 7:46 pm
Mind you, I am not saying that I endorse Hansen’s current view that there is a serious possibility that we could trigger a runaway greenhouse effect. However, if you want to effectively argue against it, you have to do so by actually presenting scientific arguments, not by attacking strawmen versions of Hansen’s scientific arguments.
Actually Hansen needs to prove that it’s even possible. I don’t think he’s done that. Then he needs to explain why it hasn’t happened in the past.
Joseph
December 25, 2008 7:50 pm
Re: foinavon (16:13:03)
I have to agree with your assessment of Scotese’s temperature graph. I have searched (online only) for an explanation from him of this conclusion (his graph) and cannot locate it. I have read at various blogs and forums (sorry, no links) that what he did was to assume that if there was no evidence of ice at the poles, or continental glaciers, he assumed an average global temperature of 22 °C; with ice at the poles (or continental glaciers), he assumed an average global temperature of 12 °C. They were assumptions of the model that he used. The wiggles in between these temperatures were deduced from his analysis of the distribution of sedimentary rock types (and coal and fossils), their position on the planet, and the climatic conditions conducive to their formation. In other words, most of his temperature graph is modeled on assumptions, not data.
If anyone is aware of information to the contrary, please post it.
Jeff Alberts
December 25, 2008 8:03 pm
The temperature increase is from the total greenhouse effect of all greenhouse gases – including water vapor and CO2.
Over the oceans, the water vapor is already there – its presence doesn’t depend on the presence of CO2 – and its greenhouse effect is very large compared to that of CO2, and even larger compared with the added CO2.
So almost all of the greenhouse warming effect, from the time the sun rises and starts warming the ocean, is due to the water vapor itself.
You mean tossing a lit match into a roaring fire won’t cause the fire to go runaway and explode??
Mike Bryant
December 25, 2008 9:16 pm
Joseph, you said:
“Our biosphere is unequally heated by the sun. The greenhouse effect acts to transport heat from areas where there is more heat to areas where there is less heat, both horizontally across the planet’s surface and vertically within the atmosphere. The greenhouse effect also acts to ameliorate the difference between daytime highs and nighttime lows.”
—————————–
Does this suggest that a more complete greenhouse, with much more water vapor might actually make the deserts cooler during the day and warmer at night? Might the poles warm and open up areas for habitation? Might the increase of water vapor in the atmosphere lessen the sea level rise? Might any lands lost to sea level rise be replaced by more temperate regions being created? I know this is extremely speculative on my part. But nothing whatsoever is more speculative than catastrophic global warming.
Phil
December 25, 2008 11:45 pm
Joel Shore (18:41:44) :
“Well, the “bare radiative effect” of doubling CO2 is to increase the temperature by about 1.1 C, give or take about a tenth of a degree.”
Thanks. Do you have a source for that?
Also, disregarding for the moment other factors,I would like to try to understand the asserted water feedback contribution specifically. How does that happen and what is the mathematical formulation that describes it?
Peter
December 26, 2008 4:18 am
Joel Shore:
It is hard to ascribe a rigorous percentage of the effect to water vapor and CO2 because the effects are not additive.
But this is a fundamental point, as water vapor exists over the vast bulk of the earth’s surface – wherever liquid water exists,
If you cannot ascribe a rigorous percentage to this then you cannot know with any degree of accuracy anything on which this depends.
Peter
December 26, 2008 5:11 am
Sorry, that should have read, “If you cannot ascribe a rigorous percentage to this then you cannot know with any degree of accuracy anything which depends on this.”
Frank. Lansner
December 26, 2008 5:13 am
@joel Shore
you write:
“Since the air is colder as you go higher in the atmosphere and the intensity of radiation goes as the fourth power of the temperature, this means that the earth is now radiating less energy…”
I have read this more times, still not realy being able to understand your logic.
and you write:
“This means it will warm up until such point that the upper atmosphere has warmed enough that the earth is now radiating as much as it receives”
Still, your logic, your point? The warmer the more radiation, as you know. Please rephrase, I don’t understand.
You write:
“Although greenhouse gases play an important role in the overall radiation budget, the atmosphere mixes heat well enough that the… ”
Aha, so you thinkIPCC´s idea of a (not mixed!) hot spot is wrong?
But then you write:
“a more likely explanation is that the data that show the hotspot for the temperature fluctuations is correct and the data that have had a tendency not to show the hotspot for the longterm trends is not correct…And, the hotspot is really there.”
🙂 Now you believe that tere IS a hotspot ?!
To be honest: My impression is that you realy believe in the AGW, and try to argue in east and west, im sorry 🙂
K.R. Frank Lansner
Frank. Lansner
December 26, 2008 5:22 am
@Mike Bryant :
You write:
“I believe that the hot spot is hiding wherever the extra heat is hiding… in the pipeline somewhere. It is SO obvious.”
“I believe that the hot spot is hiding wherever the extra heat is hiding”
And where is that?
This reminds me of the opinion that we will see a jump in temperatures soon up to the predicted warming trend. Except the big buffer of heat, the oceans, have only been cooling. So where is the warming hiding?? On the moon?
But IPCC predicted over the tropics, 5-15 km up. So if you believe that it will appear elsewhere, you are out of line with IPCC. Which for me is no problem, though.
Joel Shore
December 26, 2008 6:07 am
Phil says:
Thanks. Do you have a source for that?
I am sure that you can find it somewhere in the IPCC report. You can also derive it, approximately at least, by using the blackbody equation for radiation balance between the earth and sun plus the fact that doubling CO2 changes the radiative forcing at the top of the atmosphere by about 4 W/m^2.
Also, disregarding for the moment other factors,I would like to try to understand the asserted water feedback contribution specifically. How does that happen and what is the mathematical formulation that describes it?
Sorry that I forgot the link for the C-C equation. You can find it here: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/clausius.php
As for any simple mathematical formulation for the complete water vapor feedback, I don’t think there is any that I know of. The computed feedback comes out of the climate models (and, even then, I think there may be a little bit of “play” in how you define a certain temperature change to this feedback since the feedbacks can interact with each other and so are not strictly additive or multiplicative).
I once wrote up a simplified model of the water vapor feedback that assumed the fact that the dependence of temperature on CO2 concentration was logarithmic , the dependence of temperature on water vapor on concentration was logarithmic, and the dependence of water vapor concentration on temperature maintained constant relative humidity. It was useful to illustrate some basic principles of the feedback but it was clearly a simplified model and it had at least one parameter (the coefficient for the dependence of temperature on water vapor on concentration) that I didn’t have any good estimate for and just ended up estimating by working backwards from what I knew to be the approximate estimated strength of the water vapor feedback.
Joel Shore
December 26, 2008 6:18 am
Joseph says:
You are also mistaken concerning the nature of the greenhouse effect. Did you visit the links I provided? If there was no greenhouse effect to transport the heat away from our planet’s surface towards the upper atmosphere and the poles, primarily through convection, our planet’s surface temperature would average approximately 170 °F.
Our biosphere is unequally heated by the sun. The greenhouse effect acts to transport heat from areas where there is more heat to areas where there is less heat, both horizontally across the planet’s surface and vertically within the atmosphere. The greenhouse effect also acts to ameliorate the difference between daytime highs and nighttime lows.
It is true that the number that I quoted of -18 C for the blackbody temperature of the earth assumes infinitely fast transport of heat across the earth so that it is at a uniform temperature. However, the effect of the temperature being non-uniform is actually to LOWER, not raise that average temperature. (This is because the heat radiated depends on the fourth power of the temperature. So, as a simple example, if half of the earth was at 0 K and the other half was at 510 K [double the 255 K, i.e., -18 C] then the average temperature would be 255 K but the amount of heat radiated would be much larger than if the entire earth was at 255 K…in fact, 8X as large, because of the strongly nonlinear dependence of heat radiated on the temperature…So, clearly the average temperature of such an unequal earth has to be lower.)
So, I can’t see how you can possibly get the result that the AVERAGE temperature of the earth in the absence of the greenhouse effect would be 170 F, although depending on the assumptions you make concerning heat transport on a greenhouse-less earth, I see how you could potentially get a result that says that the temperature of the part facing the sun could be this high.
Bill Illis
December 26, 2008 6:21 am
In regards to Hansen’s runaway greenhouse possibility, if your model is based on unrealistic GHG impacts, one could see how a runaway greenhouse event could occur.
As the final piece of evidence why the global warming models (and foinavon’s formula) are unrealistically high, consider what happens over geologic time when CO2 levels were as high as 3,000 ppm or 7,000 ppm for example.
Hansen’s model and foinavon’s formula produce temperatures that are as much as 12C to 13C higher than current temps which does not appear to have happened in Earth’s climate history.
While the warming to date Log or Ln formulas produce warming levels of 6C to 8C which more closely matches the temperature record – whether you use the Scotese chart or the more-up-to-date higher resolution ones from Wikipedia/global warming art
– note that the Sun was a little weaker as you go back farther in time and the position of the continents over geologic time is important as well – the more the continents are weighted toward the poles, the colder Earth’s climate becomes – 600 million years ago and 300 million years ago, more than half of the continents were locked together over the south pole which created huge continental glaciers and cooled the planet – glaciers do not form on the ocean – ocean circulation patterns were much different when deep ocean currents could enter the Arctic through the Pacific or cross from the Atlantic to the Pacific between the America’s continents etc. etc.
– Warming Models over geologic time: http://img440.imageshack.us/img440/3291/co2tempgeotnc8.png
– Earth’s Temp history over the last 540 million years: http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/All_palaeotemps.png/800px-All_palaeotemps.png
– CO2 estimates over the last 540 million years (Berner’s GeoCarb III yellow-orange line is the most accepted): http://www.globalwarmingart.com/images/7/76/Phanerozoic_Carbon_Dioxide.png
foinavon
December 26, 2008 6:33 am
Joseph (18:42:52) :
I think we’re completely on the same wavelength. My comment that you are questioning was made in a post [23.12.2008 (05:53:08)] illustrating that the evidence supports that the ocean surface is warming due to enhanced greenhouse forcing (rather than as inferred from ill-characterized ideas about redistribution of heat from the deep and so on).
So it’s really an answer to the questions why has the ocean surface warmed during the last 40 years</i?…or why has the heat content of the surface layers of the oceans increased so much since the 1960’s
The answer is that changes in the composition of the atmosphere has increased the radiative imbalance resulting in the accumulation of “excess” heat in the oceans. That’s the respect in which one can say it’s the atmosphere that has warmed the oceans. If one considers the mechanism my statement is lazy and your explanation (but not Mr. Wilde’s!) is fine.
And “reduced cooling” does mean “more warming”, if during a previous nearer-equilibrium state (e.g. as described in the NOAA site you linked to) the cooling was more or less balanced by warming (heat input and output near equilibrium). That’s the only way one can accomodate your idea of “reduced cooling” with the extant reality of warming!
However one swings it, enhanced greenhouse gas concentrations has resulted in a rather significant radiative imbalance which has resulted in a very significant penetration of warmth into the ocean surface layers which have warmed as a result (and I mean this in the same sense as [***]).
[***] T. P. Barnett et al. (2005) Penetration of Human-Induced Warming into the World’s Oceans Science 309, 284 – 287.
Mike Bryant
December 26, 2008 7:07 am
Frank. Lansner,
You said:
“This reminds me of the opinion that we will see a jump in temperatures soon up to the predicted warming trend. Except the big buffer of heat, the oceans, have only been cooling. So where is the warming hiding?? On the moon?”
Well, so many people were jumping on Joel that I was feeling sorry for him so I thought I would help him out. It’s not his fault that the extra heat is so good at hiding from us.
Mike Bryant
Joel Shoer wrote:
“…I also hold no illusions that I will be able to convince everyone. There are people around (commenting on this very website, in fact) who still don’t believe that CFCs impact the ozone layer…”
To convince others, you may have to rethink your attitude towards science.
Recently, the first experiment to measure the CFCs impact on the ozone layer has demonstrated, that the previously assumed and computer simulated mechanism was at least one order of magnitude weaker than expected. It shurely takes more exerimental data to confirm this, but presently experimental evidence is not supporting previous consensus.
The author of the peer reviewed papaer therefore stated, that scientific consensus was shattered and that science may have to to start all over again.
Therefore I can’t follow your remark ridiculing others, who feel more comfortable with experimental evidence than computer models.
Bill Illis (05:37:46) :
You’ve misunderstood again. I’m not “crapping” on your formula at all. You should try to read posts carefully because very often the writers make an effort to say clearly what they mean! Go back to my post [21:12:08 (12:52:53)] and you’ll see that I pointed out that my equation was essentially the same as yours[***].
The problem is with your representation of the data in the article at the top of this thread. It is highly misleading in relation to the issue at hand which is the effect of raising atmospheric CO2 levels by very large amounts. The only reason I can think of that anyone would represent the temperature variation expected with CO2 variations, starting from near 0 ppm is to create the impression that increasing CO2 from today’s levels would have little effect, since the data is massively dominated by the completely irrelevant range between 0 and 100 ppm.
That’s very misleading. Therefore I included an equation so that anyone sufficiently interested could address this themselves, for example by calculating (in Excel, for example) the CO2/temp relationship (within a 3 oC climate sensitivity) over the range 280-600/700 ppm (e.g. to assess what might acrue during this century if we don’t make an effort to limit or sequester emissions), or the range 280-3000 ppm, if we seriously want to address Hansen’s “burning all the coal and tar-sands” scenario.
The other problem with your graph has already been highlighted very well by Chris V, which is the extremely well-understood fact that the climate sensitivity relates to the temperature increase at equilibrium. You’ve chosen to ignore that in your red plot it seems.
[***]my equation is rather better than yours (!) since it is transparent and versatile. I’ve kept the values for the climate sensitivity and the temperature normalization independently-defined, so that the equation can be used to assess the effects of any chosen climate sensitivity (3.0 below) and any chosen normalization (9.39 below which gives an absolute temperature of 15oC at 280 ppm). That doesn’t make it “complicated”!
T = (3.0/log(2))*(log(C))-9.39
Joel Shore:
The temperature increase is from the total greenhouse effect of all greenhouse gases – including water vapor and CO2.
Over the oceans, the water vapor is already there – its presence doesn’t depend on the presence of CO2 – and its greenhouse effect is very large compared to that of CO2, and even larger compared with the added CO2.
So almost all of the greenhouse warming effect, from the time the sun rises and starts warming the ocean, is due to the water vapor itself.
Wondering Aloud (07:22:50)
I described the problem here [22.12.08 (10:47:01)]
The truncated version of Scotese’s graph in the article at the top of this thread is an extremely crude and outdated sketch of temperature in the deep past. I don’t know where the data has come from. Do you? We’d surely like to know that, but I can’t find it on Scotese’s site. It’s O.K in the context of Scotese’s very nice site on paeogeology (the version on his site is somewhat better. But it doesn’t bear much relation to our current understanding of paleotemperature and it certainly shouldn’t be used alongside the CO2 model (time resolution of the model one data point every 10 million years) to “assess” the relationships between temperature and CO2 levels in the past. We can only do that where we have contemporaneous proxies for CO2 and temperature.
There’s a wealth of paleotemperature data in the scientific literature. Even this version on Wikipedia is sufficient to illustrate that the truncated Scotese sketch is not very scientific (and we can see where the data comes from!):
http://en.wikipedia.org/wiki/File:All_palaeotemps.png
Joel Shore (14:28:34) :
“More precisely, the concentration of water vapor is dependent on the temperature. So, as the direct effect of the CO2 causes temperatures to rise, the concentration of water vapor increases and you get additional warming (a positive feedback) from that. Of course, if something else other than CO2 (like an increase in solar irradiance) caused the initial warming, you would still get the same water vapor feedback effect…It is not specific to the cause of the warming being CO2.”
Please help me understand this a little better. I understand that the amount of water that air can hold is dependent on temperature (by the way, the link didn’t come through). That much is clear. My question is: what is the formula that governs how additional CO2 puts more water vapor into the air and what is the mechanism by which that is asserted to happen? That is why I asked what the climate sensitivity is asserted to be for CO2 without water vapor, under the assumption (perhaps misunderstood) that there would then be a formulaic relationship that would add the water feedback in, thus resulting in the asserted 3°C per doubling of CO2. What are the intermediate steps expressed mathematically?
foinavon, the formula is important at the lower end of the CO2 spectrum as well because it tells you something important about the expected relative humidity response of warming/GHGs.
The formula at the extremes of the possible responses says that CO2/GHGs are responsible for nearly the entire greenhouse effect (when the secondary impact on water vapour is included).
That says the assumptions included in the formulas and in the models is based on relative humidity staying broadly constant. If that is not expected to occur at the extremes, then maybe it is not accurate for the current spectrum of CO2/GHG values as well.
If the formula does not hold through all possible values then how can we be sure it is valid for the current spectrum of values.
What if relative humidity declines by 10% (4 percentage points) as GHGs reach their equilibrium forcing level. Warming then only amounts to 1.5C rather than 3.0C.
I spelled this out in another chart more than a month ago (some of the values in the chart have changed since then.)
http://i463.photobucket.com/albums/qq360/Bill-illis/LackofWarmingExplained.png
Manfred (15:42:52) wrote:
“Recently, the first experiment to measure the CFCs impact on the ozone layer has demonstrated, that the previously assumed and computer simulated mechanism was at least one order of magnitude weaker than expected.”
I can’t find anything about this. Link?
Rather confusingly Mr Wilde is a Fellow of the Royal Meteorological Society however he is not entitled to use the FRMetSoc designation that indicates professional Meteorological experience or competence.
The rules changed in 2003, before that it was possible for an enthusiastic layman or amateur to become a Fellow without any verified proof of Meteorological aptitude. Existing Fellows were not relieved of their title at the time of the rule change and may continue to use it as an honorarium.
To be fair Wilde makes this clear in the first article of his series on CO2Sceptics site, yet still starts many subsequent pieces with Stephen Wilde has been a Fellow of the Royal Meteorological Society since 1968. which is bound to lead the casual reader to infer that they are reading a piece by a professional Meteorologist rather than an amateur.
I too was struck by the contrast between this claim of Wilde’s academic recognition and the many errors of basic science in his writings, which led to an exchange with Mr Wilde on this very blog …
[Comments 09:02:38 onwards]
Hope this unmuddies the waters a little.
JP.
<Re: Joel Shore (14:28:34) says
Not sure where you get this from. It is an elementary physics problem to work out that the blackbody radiative temperature of the earth (having the albedo of ~30% in the visible that it does) corresponds to about -18 C (or 255 K). The reason why the average surface temperatures are significantly warmer than this (~15 C) is because of the greenhouse effect.
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No. That is incorrect. Your invocation of the blackbody radiative temperature of the earth concerns the radiation of our planet and the atmosphere, taken as a whole (the biosphere), radiating into space. That IS in radiative equilibrium, with the temperature of the system as you stated. My discussion with foinavon concerns the transfer of heat from the planet’s surface (the ocean) to the atmosphere, within that system, not our biosphere’s blackbody temperature, or radiation of heat into space. The transfer of heat from our planet’s surface to the upper atmosphere is mostly convective, not radiative.
You are also mistaken concerning the nature of the greenhouse effect. Did you visit the links I provided? If there was no greenhouse effect to transport the heat away from our planet’s surface towards the upper atmosphere and the poles, primarily through convection, our planet’s surface temperature would average approximately 170 °F.
Our biosphere is unequally heated by the sun. The greenhouse effect acts to transport heat from areas where there is more heat to areas where there is less heat, both horizontally across the planet’s surface and vertically within the atmosphere. The greenhouse effect also acts to ameliorate the difference between daytime highs and nighttime lows.
Have you ever been to a desert area? The air there is very dry. It’s the reason why it can be blisteringly hot during the day, and still drop below freezing at night. Very little greenhouse effect.
Cheers!
Peter says:
Well, we are simply talking about different things. Looking back at the original post that I was responding to, it was talking about increasing CO2 levels and the water vapor feedback, not the original of the entire natural greenhouse effect. I agree that the large majority of the natural greenhouse effect is due to water vapor. (It is hard to ascribe a rigorous percentage of the effect to water vapor and CO2 because the effects are not additive.)
By the way, I noticed in looking back at Phil’s original post that I never did answer this question of his:
Well, the “bare radiative effect” of doubling CO2 is to increase the temperature by about 1.1 C, give or take about a tenth of a degree. However, the water vapor feedback isn’t the only feedback effect to consider. There are other positive feedbacks like the ice-albedo feedback (land and sea ice melting makes the earth less reflective so it absorbs more solar energy), negative feedbacks like the the lapse rate feedback that I mentioned above, and then there is of course the feedback due to clouds. The cloud feedback is currently the biggest source of uncertainty and differences between the models.
Re: foinavon (15:17:50)
foinavon, I think you are confused. Atmospheric changes that result in a reduction of the transfer of the heat from the ocean to the atmosphere does not translate into; “Yes, there’s pretty good evidence that the atmosphere has warmed the oceans.”. Reduced cooling does not mean warming. The ocean is heated by the sun. Changes in the atmosphere cannot add additional heat to the ocean, it can only affect the rate at which heat is lost from the ocean, nothing more.
Actually Hansen needs to prove that it’s even possible. I don’t think he’s done that. Then he needs to explain why it hasn’t happened in the past.
Re: foinavon (16:13:03)
I have to agree with your assessment of Scotese’s temperature graph. I have searched (online only) for an explanation from him of this conclusion (his graph) and cannot locate it. I have read at various blogs and forums (sorry, no links) that what he did was to assume that if there was no evidence of ice at the poles, or continental glaciers, he assumed an average global temperature of 22 °C; with ice at the poles (or continental glaciers), he assumed an average global temperature of 12 °C. They were assumptions of the model that he used. The wiggles in between these temperatures were deduced from his analysis of the distribution of sedimentary rock types (and coal and fossils), their position on the planet, and the climatic conditions conducive to their formation. In other words, most of his temperature graph is modeled on assumptions, not data.
If anyone is aware of information to the contrary, please post it.
You mean tossing a lit match into a roaring fire won’t cause the fire to go runaway and explode??
Joseph, you said:
“Our biosphere is unequally heated by the sun. The greenhouse effect acts to transport heat from areas where there is more heat to areas where there is less heat, both horizontally across the planet’s surface and vertically within the atmosphere. The greenhouse effect also acts to ameliorate the difference between daytime highs and nighttime lows.”
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Does this suggest that a more complete greenhouse, with much more water vapor might actually make the deserts cooler during the day and warmer at night? Might the poles warm and open up areas for habitation? Might the increase of water vapor in the atmosphere lessen the sea level rise? Might any lands lost to sea level rise be replaced by more temperate regions being created? I know this is extremely speculative on my part. But nothing whatsoever is more speculative than catastrophic global warming.
Joel Shore (18:41:44) :
“Well, the “bare radiative effect” of doubling CO2 is to increase the temperature by about 1.1 C, give or take about a tenth of a degree.”
Thanks. Do you have a source for that?
Also, disregarding for the moment other factors,I would like to try to understand the asserted water feedback contribution specifically. How does that happen and what is the mathematical formulation that describes it?
Joel Shore:
But this is a fundamental point, as water vapor exists over the vast bulk of the earth’s surface – wherever liquid water exists,
If you cannot ascribe a rigorous percentage to this then you cannot know with any degree of accuracy anything on which this depends.
Sorry, that should have read, “If you cannot ascribe a rigorous percentage to this then you cannot know with any degree of accuracy anything which depends on this.”
@joel Shore
you write:
“Since the air is colder as you go higher in the atmosphere and the intensity of radiation goes as the fourth power of the temperature, this means that the earth is now radiating less energy…”
I have read this more times, still not realy being able to understand your logic.
and you write:
“This means it will warm up until such point that the upper atmosphere has warmed enough that the earth is now radiating as much as it receives”
Still, your logic, your point? The warmer the more radiation, as you know. Please rephrase, I don’t understand.
You write:
“Although greenhouse gases play an important role in the overall radiation budget, the atmosphere mixes heat well enough that the… ”
Aha, so you thinkIPCC´s idea of a (not mixed!) hot spot is wrong?
But then you write:
“a more likely explanation is that the data that show the hotspot for the temperature fluctuations is correct and the data that have had a tendency not to show the hotspot for the longterm trends is not correct…And, the hotspot is really there.”
🙂 Now you believe that tere IS a hotspot ?!
To be honest: My impression is that you realy believe in the AGW, and try to argue in east and west, im sorry 🙂
K.R. Frank Lansner
@Mike Bryant :
You write:
“I believe that the hot spot is hiding wherever the extra heat is hiding… in the pipeline somewhere. It is SO obvious.”
“I believe that the hot spot is hiding wherever the extra heat is hiding”
And where is that?
This reminds me of the opinion that we will see a jump in temperatures soon up to the predicted warming trend. Except the big buffer of heat, the oceans, have only been cooling. So where is the warming hiding?? On the moon?
But IPCC predicted over the tropics, 5-15 km up. So if you believe that it will appear elsewhere, you are out of line with IPCC. Which for me is no problem, though.
Phil says:
I am sure that you can find it somewhere in the IPCC report. You can also derive it, approximately at least, by using the blackbody equation for radiation balance between the earth and sun plus the fact that doubling CO2 changes the radiative forcing at the top of the atmosphere by about 4 W/m^2.
Sorry that I forgot the link for the C-C equation. You can find it here: http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/clausius.php
As for any simple mathematical formulation for the complete water vapor feedback, I don’t think there is any that I know of. The computed feedback comes out of the climate models (and, even then, I think there may be a little bit of “play” in how you define a certain temperature change to this feedback since the feedbacks can interact with each other and so are not strictly additive or multiplicative).
I once wrote up a simplified model of the water vapor feedback that assumed the fact that the dependence of temperature on CO2 concentration was logarithmic , the dependence of temperature on water vapor on concentration was logarithmic, and the dependence of water vapor concentration on temperature maintained constant relative humidity. It was useful to illustrate some basic principles of the feedback but it was clearly a simplified model and it had at least one parameter (the coefficient for the dependence of temperature on water vapor on concentration) that I didn’t have any good estimate for and just ended up estimating by working backwards from what I knew to be the approximate estimated strength of the water vapor feedback.
Joseph says:
It is true that the number that I quoted of -18 C for the blackbody temperature of the earth assumes infinitely fast transport of heat across the earth so that it is at a uniform temperature. However, the effect of the temperature being non-uniform is actually to LOWER, not raise that average temperature. (This is because the heat radiated depends on the fourth power of the temperature. So, as a simple example, if half of the earth was at 0 K and the other half was at 510 K [double the 255 K, i.e., -18 C] then the average temperature would be 255 K but the amount of heat radiated would be much larger than if the entire earth was at 255 K…in fact, 8X as large, because of the strongly nonlinear dependence of heat radiated on the temperature…So, clearly the average temperature of such an unequal earth has to be lower.)
So, I can’t see how you can possibly get the result that the AVERAGE temperature of the earth in the absence of the greenhouse effect would be 170 F, although depending on the assumptions you make concerning heat transport on a greenhouse-less earth, I see how you could potentially get a result that says that the temperature of the part facing the sun could be this high.
In regards to Hansen’s runaway greenhouse possibility, if your model is based on unrealistic GHG impacts, one could see how a runaway greenhouse event could occur.
As the final piece of evidence why the global warming models (and foinavon’s formula) are unrealistically high, consider what happens over geologic time when CO2 levels were as high as 3,000 ppm or 7,000 ppm for example.
Hansen’s model and foinavon’s formula produce temperatures that are as much as 12C to 13C higher than current temps which does not appear to have happened in Earth’s climate history.
While the warming to date Log or Ln formulas produce warming levels of 6C to 8C which more closely matches the temperature record – whether you use the Scotese chart or the more-up-to-date higher resolution ones from Wikipedia/global warming art
– note that the Sun was a little weaker as you go back farther in time and the position of the continents over geologic time is important as well – the more the continents are weighted toward the poles, the colder Earth’s climate becomes – 600 million years ago and 300 million years ago, more than half of the continents were locked together over the south pole which created huge continental glaciers and cooled the planet – glaciers do not form on the ocean – ocean circulation patterns were much different when deep ocean currents could enter the Arctic through the Pacific or cross from the Atlantic to the Pacific between the America’s continents etc. etc.
– Warming Models over geologic time:
http://img440.imageshack.us/img440/3291/co2tempgeotnc8.png
– Earth’s Temp history over the last 540 million years:
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/All_palaeotemps.png/800px-All_palaeotemps.png
– CO2 estimates over the last 540 million years (Berner’s GeoCarb III yellow-orange line is the most accepted):
http://www.globalwarmingart.com/images/7/76/Phanerozoic_Carbon_Dioxide.png
Joseph (18:42:52) :
I think we’re completely on the same wavelength. My comment that you are questioning was made in a post [23.12.2008 (05:53:08)] illustrating that the evidence supports that the ocean surface is warming due to enhanced greenhouse forcing (rather than as inferred from ill-characterized ideas about redistribution of heat from the deep and so on).
So it’s really an answer to the questions why has the ocean surface warmed during the last 40 years</i?…or why has the heat content of the surface layers of the oceans increased so much since the 1960’s
The answer is that changes in the composition of the atmosphere has increased the radiative imbalance resulting in the accumulation of “excess” heat in the oceans. That’s the respect in which one can say it’s the atmosphere that has warmed the oceans. If one considers the mechanism my statement is lazy and your explanation (but not Mr. Wilde’s!) is fine.
And “reduced cooling” does mean “more warming”, if during a previous nearer-equilibrium state (e.g. as described in the NOAA site you linked to) the cooling was more or less balanced by warming (heat input and output near equilibrium). That’s the only way one can accomodate your idea of “reduced cooling” with the extant reality of warming!
However one swings it, enhanced greenhouse gas concentrations has resulted in a rather significant radiative imbalance which has resulted in a very significant penetration of warmth into the ocean surface layers which have warmed as a result (and I mean this in the same sense as [***]).
[***] T. P. Barnett et al. (2005) Penetration of Human-Induced Warming into the World’s Oceans Science 309, 284 – 287.
Frank. Lansner,
You said:
“This reminds me of the opinion that we will see a jump in temperatures soon up to the predicted warming trend. Except the big buffer of heat, the oceans, have only been cooling. So where is the warming hiding?? On the moon?”
Well, so many people were jumping on Joel that I was feeling sorry for him so I thought I would help him out. It’s not his fault that the extra heat is so good at hiding from us.
Mike Bryant